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Sample records for sodium bicarbonate solution

  1. Solubility of ammonium metavanadate in ammonium carbonate and sodium bicarbonate solutions at 25 deg C

    International Nuclear Information System (INIS)

    Solubility at 25 deg C has been studied in the system ammonium metavanadate - sodium bicarbonate - water which is a stable section of the corresponding quaternary mutual system. In the eutonic point the content of ammonium metavanadate is 4.95% and of sodium bicarbonate 12.1%. The crystallization branch of ammonium metavanadate has been studied in the system ammonium metavanadate - ammonium carbonate - water at 25 deg C. Metavanadate solubility attains minimum (0.14%) at ammonium carbonate concentration 2.6%. Three sections have been studied of the quaternary system ammonium - metavanadate - ammonium carbonate - sodium bicarbonate-water at 25 deg C in the crystallization region of ammonium metavanadate at a ratio of sodium bicarbonate to ammonium carbonate 3:1, 1:1, and 1:3. A region of minimum solubility of ammonium metavanadate has been detected (0.1%)

  2. 21 CFR 184.1736 - Sodium bicarbonate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium bicarbonate. 184.1736 Section 184.1736 Food... Specific Substances Affirmed as GRAS § 184.1736 Sodium bicarbonate. (a) Sodium bicarbonate (NaHCO3, CAS Reg. No. 144-55-8) is prepared by treating a sodium carbonate or a sodium carbonate and sodium...

  3. The anodic dissolution of SIMFUEL (UO2) in slightly alkaline sodium carbonate/bicarbonate solutions

    International Nuclear Information System (INIS)

    The corrosion of nuclear fuel under waste disposal conditions is likely to be influenced by the bicarbonate/carbonate content of the groundwater since it increases the solubility of the UVI corrosion product, [UO2]2+. As one of the half reactions involved in the corrosion process, the anodic dissolution of SIMFUEL (UO2) has been studied in bicarbonate/carbonate solutions (pH 9.8) using voltammetric and potentiostatic techniques and electrochemical impedance spectroscopy. The reaction proceeds by two consecutive one electron transfer reactions (UIV ? UV ? UVI). At low potentials (?250 mV (vs. SCE) the rate of the first electron transfer reaction is rate determining irrespective of the total carbonate concentration. At potentials >250 mV (vs. SCE) the formation of a UVIO2CO3 surface layer begins to inhibit the dissolution rate and the current becomes independent of potential indicating rate control by the chemical dissolution of this layer.

  4. 21 CFR 582.1736 - Sodium bicarbonate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium bicarbonate. 582.1736 Section 582.1736 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1736 Sodium bicarbonate. (a) Product. Sodium bicarbonate. (b) Conditions of use....

  5. Sodium Bicarbonate mouth rinse: An Uncommon Complication

    Directory of Open Access Journals (Sweden)

    Fatih Mehmet Coskunses

    2012-02-01

    Full Text Available Sodium bicarbonate is a natural buffer that maintains a healthy pH in mouth to promote a clean and fresh oral environment. Sodium-bicarbonate rinse is empirically suggested to patients by dentist and people around, and may prove to be harmful. In this short communication, we present chemical burn of oral mucosa because of sodium-bicarbonate rinse after misfit dental impression.

  6. Oxidation of Am(III) in carbonate - bicarbonate solution by sodium perxenate

    International Nuclear Information System (INIS)

    The oxidation of Am(III) by Na4XeO6 in KHCO3, KHCO3 + K2CO3, and K2CO3 solutions is studied by spectrophotometry. In 1.5M solutions (HCO3- + CO32-) with perxenate concentrations comparable to those of Am, Am(III) is quickly converted to a mixture of Am(IV) + Am(V) + Am(VI). In concentrated K2CO3 solutions (5.9 M), Am(III) is in general not oxidized by perxenate. A mechanism is proposed for the oxidation of Am(III) by perxenate that includes the reaction of Am(III) with Xe(VIII) and possibly with Xe(VI). The reaction of Na4XeO6 and Am(IV) was also investigated. In this instance Am(IV) was quickly converted to Am(V) and Am(VI)

  7. Postharvest behaviour of two Sardinian apple varieties following immersion in heated sodium bicarbonate solution.

    Science.gov (United States)

    Venditti, T; Molinu, M G; Dore, A; Agabbio, M; D'Hallewin, G

    2010-01-01

    'Miali' and 'Caddina' are apple varieties of Sardinian germplasm, mainly produced under sustainable conditions. Fruit is rarely subjected to cold storage and postharvest losses are generally high. In order to prolong the marketing period and contain postharvest decay of these local varieties, we investigated on their storage behaviour and on the efficacy of combined alternative postharvest treatments. Pre-climateric fruit was harvested and immersed for 0 (control), 15, 30, 45 or 60 sec. in water at 20, 50, 55 or 60 degrees C with or without 2% (W/V) NaHCO3 (SBC). Then, fruit was stored for 4 months at 5 degrees C and 90% RH followed by a 6 day simulated marketing period (SMP) at 10 degrees C and 75% RH. Decay was monitored at the end of storage and after the SMP, while appearance and physiological disorders were evaluated after SMP. During storage 56 and 62% of the untreated 'Caddina' and 'Miali' apples rotted, respectively. During the SMP, an additional 3% of 'Caddina' and 5% of 'Miali' was lost. Among the treatments the best decay control, for both varieties, was attained when fruit was immersed in the SBC solution at 55 degrees C for 60 sec. Compared to control, decay was reduced by 91 and 95% for 'Caddina' and 'Miali', respectively. This combination induced some rind damage, mainly on 'Caddina' fruit. Superficial scald was evident on 'Caddina' and scored as medium while, cold storage induced a significant deposition of epicuticular wax in 'Miali' fruit, affecting significantly fruit appearance. A significant reduction of decay was also achieved when fruit was immersed at 60 degrees C for 30 or 45 sec., attaining for 'Caddina' a reduction of 82 and 88% of decay, respectively. Other combinations were lesser effective or produced rind damages and most decay was caused by Penicillium expansum. PMID:21534486

  8. Sodium-Coupled Bicarbonate Transporters

    Directory of Open Access Journals (Sweden)

    Boron WF

    2001-07-01

    Full Text Available Together, the Na(+-coupled HCO(3(- transporters and the AE family of anion exchangers (i.e., Cl-HCO3 exchangers comprise the bicarbonate transporter (BT superfamily. Virtually all BTs are important for the regulation of intracellular pH (pH(i in cells throughout the body. Specific BTs also play roles in cell-volume regulation, as well as for the transport of salt and/or acid-base equivalents across many epithelia. Electrogenic Na/HCO3 cotransporters (NBCe's play key roles in HCO(3(- reabsorption by the renal proximal tubule, and HCO(3(- secretion by the pancreatic duct. Electroneutral NBC's (NBCn's regulate pH(i in vascular smooth muscle and are present in/near axons in the brain. Finally, the Na(+-driven Cl-HCO3 exchanger (NDCBE's appear to be the major pH(i regulators in CNS neurons. A characteristic of most, but not all, BT's is that they are inhibited rather effectively by 4,4'-diisothiocyanostilbene-4,4'-disulfonate (DIDS.

  9. Gram-scale solution-phase synthesis of selective sodium bicarbonate Co-transport Inhibitor S0859

    DEFF Research Database (Denmark)

    Larsen, Ann Møller; Krogsgaard-Larsen, Niels; Lauritzen, Gitte; Olesen, Christina W.; Hansen, Steen Honore'; Bødtkjer, Ebbe; Pedersen, Stine Helene Falsig; Bunch, Lennart

    2012-01-01

    Na+-coupled HCO3- transporters (NBCs) mediate the transport of bicarbonate ions across cell membranes and are thus ubiquitous regulators of intracellular pH. NBC dysregulation is associated with a range of diseases; for instance, NBCn1 is strongly up-regulated in a model of ErbB2-dependent breast...... cancer, a malignant and widespread cancer with no targeted treatment options, and single-nucleotide polymorphisms in NBCn1 genetically link to breast cancer development and hypertension. The N-cyanosulfonamide S0859 has been shown to selectively inhibit NBCs, and its availability on the gram scale is...... murine cancer cell lines in Ringer solutions. However, S0859 binds very strongly to components in plasma, and accordingly, measurements on isolated murine tissues showed no effect of S0859 at concentrations up to 50 mu M....

  10. Leaching of uranium from Syrian phosphorite (sodium carbonate-bicarbonate)

    International Nuclear Information System (INIS)

    The leaching of uranium from Syrian phosphorite by sodium carbonate-bicarbonate solution has been studied, using a batch technique. Parameters influencing percentage extraction of uranium that are considered and studies in this work are: Leachant concentration, particle size, heat treatment, leachant renewal, phosphorite renewal and contact time. All measurements of uranium from aqueous solutions were carried out by fluorometry. (author). 12 refs., 4 figs., 1 tab

  11. 40 CFR 415.140 - Applicability; description of the sodium bicarbonate production subcategory.

    Science.gov (United States)

    2010-07-01

    ... sodium bicarbonate production subcategory. 415.140 Section 415.140 Protection of Environment... POINT SOURCE CATEGORY Sodium Bicarbonate Production Subcategory § 415.140 Applicability; description of the sodium bicarbonate production subcategory. The provisions of this subpart are applicable...

  12. The origin of high sodium bicarbonate waters in the Atlantic and Gulf Coastal Plains

    Science.gov (United States)

    Foster, M.D.

    1950-01-01

    Some sodium bicarbonate waters at depth in the Atlantic and Gulf Coastal Plains have the same bicarbonate content as the shallower calcium bicarbonate waters in the same formation and appear to be the result of replacement of calcium by sodium through the action of base-exchange minerals. Others, however, contain several hundred parts per million more of bicarbonate than any of the calcium bicarbonate waters and much more bicarbonate than can be attributed to solution of calcium carbonate through the action of carbon dioxide derived from the air and soil. As the waters in the Potomac group (Cretaceous) are all low in sulphate and as the environmental conditions under which the sediments of the Potomac group were deposited do not indicate that large amounts of sulphate are available for solution, it does not seem probable that carbon dioxide generated by chemical or biochemical breakdown of sulphate is responsible for the high sodium bicarbonate waters in this area. Sulphate as a source of oxygen is not necessary for the generation of carbon dioxide by carbonaceous material. Oxygen is an important constituent of carbonaceous material and carbon dioxide is a characteristic decomposition product of such material-as, for example, peat and lignite. Experimental work showed that distilled water, calcium bicarbonate water, and sodium bicarbonate water, after contact with lignite, calcium carbonate, and permutite (a base-exchange material), had all increased greatly in sodium bicarbonate content and had become similar in chemical character and in mineral content to high sodium bicarbonate waters found in the Coastal Plain. The tests indicated that carbonaceous material can act as a source of carbon dioxide, which, when dissolved in water, enables it to take into solution more calcium carbonate. If base-exchange materials are also present to replace calcium with sodium, a still greater amount of bicarbonate can be held in solution. The presence of carbonaceous material, together with calcium carbonate and base-exchange minerals in a formation is, therefore, sufficient to account for the occurrence in it of high sodium bicarbonate waters. ?? 1950.

  13. Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

    International Nuclear Information System (INIS)

    It is well known that sodium bicarbonate in pharmacological doses induces transient alkalosis, causing intracellular transport of serum potassium. The aims of this study were (a) to investigate whether, in humans, myocardial thallium-201 uptake can be augmented by pretreatment with a single bolus of sodium bicarbonate at a pharmacological dose, (b) to verify general safety aspects of the intervention and (c) to evaluate the clinical implications of augmentation of 201Tl uptake, if any. Routine exercise myocardial scintigraphy was performed twice in eight adult volunteers (five normal and three abnormal), once without intervention and the second time (within a week) following intravenous administration of sodium bicarbonate (88 mEq in 50 ml) as a slow bolus 1 h prior to the injection of 201Tl. Conventional myocardial thallium study was compared with sodium bicarbonate interventional myocardial scintigraphy with respect to myocardial uptake (counts per minute per mCi injected dose), washout patterns in normal and abnormal myocardial segments, and overall clinical interpretation based on planar and single-photon emission tomographic (SPET) images. All patients remained asymptomatic after the intervention. A mean increase of 53% in myocardial uptake of thallium was noted in post-exercise acquisitions after the intervention, confirming uptake of the tracer via the potassium-hydrogen pump and its augmentation by transient alkalosis. The washout pattern remained unchanged. The visual quality of planar and SPET images improved significantly after the intervention. Out of the five abnormal myocardial segments identified in three cases, four showed significant filling-in after the intervention, causing the diagnosis to be upgraded from ''partial scar'' to ''ischaemia'', or from ''ischaemia'' to ''normal''. The overall scan impression changed in two out of three such cases. Sodium bicarbonate augmentation may have significant implications for stress-thallium scintigraphy and may be a new parameter for defining myocardial viability. (orig.)

  14. Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Sarin, Badal; Chugh, Pradeep Kumar; Kaushal, Dinesh; Soni, Nakse Lal; Sawroop, Kishan; Mondal, Anupam; Bhatnagar, Aseem [Department of Nuclear Medicine, Institute of Nuclear Medicine and Allied Sciences, Brig. S. K. Mazumdar Road, 110054, Delhi (India)

    2004-04-01

    It is well known that sodium bicarbonate in pharmacological doses induces transient alkalosis, causing intracellular transport of serum potassium. The aims of this study were (a) to investigate whether, in humans, myocardial thallium-201 uptake can be augmented by pretreatment with a single bolus of sodium bicarbonate at a pharmacological dose, (b) to verify general safety aspects of the intervention and (c) to evaluate the clinical implications of augmentation of {sup 201}Tl uptake, if any. Routine exercise myocardial scintigraphy was performed twice in eight adult volunteers (five normal and three abnormal), once without intervention and the second time (within a week) following intravenous administration of sodium bicarbonate (88 mEq in 50 ml) as a slow bolus 1 h prior to the injection of {sup 201}Tl. Conventional myocardial thallium study was compared with sodium bicarbonate interventional myocardial scintigraphy with respect to myocardial uptake (counts per minute per mCi injected dose), washout patterns in normal and abnormal myocardial segments, and overall clinical interpretation based on planar and single-photon emission tomographic (SPET) images. All patients remained asymptomatic after the intervention. A mean increase of 53% in myocardial uptake of thallium was noted in post-exercise acquisitions after the intervention, confirming uptake of the tracer via the potassium-hydrogen pump and its augmentation by transient alkalosis. The washout pattern remained unchanged. The visual quality of planar and SPET images improved significantly after the intervention. Out of the five abnormal myocardial segments identified in three cases, four showed significant filling-in after the intervention, causing the diagnosis to be upgraded from ''partial scar'' to ''ischaemia'', or from ''ischaemia'' to ''normal''. The overall scan impression changed in two out of three such cases. Sodium bicarbonate augmentation may have significant implications for stress-thallium scintigraphy and may be a new parameter for defining myocardial viability. (orig.)

  15. 40 CFR 180.1176 - Sodium bicarbonate; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Sodium bicarbonate; exemption from the... Exemptions From Tolerances § 180.1176 Sodium bicarbonate; exemption from the requirement of a tolerance. The biochemical pesticide sodium bicarbonate is exempted from the requirement of a tolerance in or on all...

  16. Influence of bicarbonate ions on the deterioration of mortar bars in sulfate solutions

    International Nuclear Information System (INIS)

    This work investigates the influence of bicarbonate ions on the deterioration of cementitious material exposed to sulfate ions. Mortars based on a CEM I and on a CEM III/B cement were investigated. Experimental investigations were compared to thermodynamic modeling and phase characterization to understand the differences in deterioration. The presence of bicarbonate ions significantly reduced the expansion of the CEM I mortars. Thermodynamic modeling showed that at high concentrations of bicarbonate ettringite and gypsum become unstable. Microstructural characterization combined with information from thermodynamic modeling suggests that conditions of high supersaturation with respect to ettringite are unlikely in the samples exposed in solutions containing bicarbonate. Consequently, expansive forces are not generated by the crystallization pressure of ettringite. There was little expansion of the CEM III/B sample even in the sodium sulfate solution. In the bicarbonate solution this mortar showed a highly leached zone at the surface in which calcite was observed.

  17. Flue Gas Desulfurization by Mechanically and Thermally Activated Sodium Bicarbonate

    Directory of Open Access Journals (Sweden)

    Walawska Barbara

    2014-09-01

    Full Text Available This paper presents the results of study on structural parameters (particle size, surface area, pore volume and the sorption ability of mechanically and thermally activated sodium bicarbonate. The sorption ability of the modified sorbent was evaluated by: partial and overall SO2 removal efficiency, conversion rate, normalized stoichiometric ratio (NSR. Sodium bicarbonate was mechanically activated by various grinding techniques, using three types of mills: fluid bed opposed jet mill, fine impact mill and electromagnetic mill, differing in grinding technology. Grounded sorbent was thermally activated, what caused a significant development of surface area. During the studies of SO2 sorption, a model gas with a temperature of 300°C, of composition: sulfur dioxide at a concentration of 6292 mg/mn3, oxygen, carbon dioxide and nitrogen as a carrier gas, was used. The best development of surface area and the highest SO2 removal efficiency was obtained for the sorbent treated by electromagnetic grinding, with simultaneous high conversion rate.

  18. Separation of uranium from sodium carbonate - sodium bicarbonate eluate by ion exchange method

    International Nuclear Information System (INIS)

    The ion exchange method was used for separating uranium from the eluate (0.5 N Na2CO3-0.5 N NaHCO3) that was obtained in the extraction process of uranium from natural sea water by using the titanium-activated carbon composite adsorbent. Uranium in the eluate containing 3 mg/1 uranium was adsorbed by ion exchange resin (Amberlite IRA-400), and was eluted with the eluant (5 % NaCl-0.5 % Na2CO3). The concentration ratio of uranium in the final concentrated-eluate became more than 20 times. The eluting solution to the adsorbent and the eluant to the resin could be repeatedly used in the desorption-ion exchange process. Sodium carbonate was consumed at the desorption step, and sodium bicarbonate was consumed at the ion exchange step. The concentration ratio of uranium was found to decrease as chloride ion in the eluate increased. (author)

  19. Separation of uranium from sodium carbonate-sodium bicarbonate eluate by ion exchange method

    International Nuclear Information System (INIS)

    The ion exchange method was used for separating uranium from the eluate (0.5 N Na2CO3-0.5 N NaHCO3) that was obtained in the extraction process of uranium from natural sea water by using the titanium-activated carbon composite adsorbent. Uranium in the eluate containing 3 mg/l uranium was adsorbed by ion exchange resin (Amberlite IRA-400), and was eluted with the eluent (5% NaCl-0.5% Na2CO3). The concentration ratio of uranium in the final concentrated-eluate became more than 20 times. The eluting solution to the adsorbent and the eluant to the resin could be repeatedly used in the desorption-ion exchange process. Sodium carbonate was consumed at the desorption step, and sodium bicarbonate was consumed at the ion exchange step. The concentration ratio of uranium was found to decrease as chloride ion in the eluate increased. (author)

  20. Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

    Scientific Electronic Library Online (English)

    Fernando Augusto Cervantes Garcia de, Sousa; Thaís Cachuté, Paradella; Cristiane Yumi, Koga-Ito; Antonio Olavo Cardoso, Jorge.

    2009-12-01

    Full Text Available The purpose of this study was to evaluate the effect of 5% sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm² specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then i [...] mmersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37ºC, the specimens were divided into four groups according to the substance used for disinfection (5% sodium bicarbonate, 0.12% digluconate chlorhexidine, vinegar and Corega Tabs). A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL). The results were analyzed through the Mann-Whitney statistical test at the 5% level of significance. Only 0.12% digluconate chlorhexidine and 5% sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively) compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12% digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12% digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5% sodium bicarbonate also proved to be a viable alternative.

  1. Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

    Directory of Open Access Journals (Sweden)

    Fernando Augusto Cervantes Garcia de Sousa

    2009-12-01

    Full Text Available The purpose of this study was to evaluate the effect of 5% sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm² specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then immersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37ºC, the specimens were divided into four groups according to the substance used for disinfection (5% sodium bicarbonate, 0.12% digluconate chlorhexidine, vinegar and Corega Tabs. A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL. The results were analyzed through the Mann-Whitney statistical test at the 5% level of significance. Only 0.12% digluconate chlorhexidine and 5% sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12% digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12% digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5% sodium bicarbonate also proved to be a viable alternative.

  2. Prevention of contrast induced nephropathy with sodium bicarbonate (the PROMEC study

    Directory of Open Access Journals (Sweden)

    John Fredy Nieto-Ríos

    2014-09-01

    Full Text Available Introduction: Contrast-induced nephropathy is a common complication of radiographic procedures. Different measures have been used to avoid this damage, but the evidence is controversial. New investigations are required to clarify it. We investigated the efficacy and safety of sodium bicarbonate solution compared with sodium chloride solution to prevent contrast induced nephropathy in patients with or at risk of renal dysfunction. Methods: A prospective, single-center, randomized clinical trial conducted from May 1, 2007 to February 8, 2008. Inpatients in a tertiary center, scheduled to undergo a procedure with the nonionic radiographic contrast agent iohexol. There were 220 patients with serum creatinine levels of at least 1.2 mg/dL (106.1 µmol/L and/or type 2 diabetics, who were randomized to receive an infusion of sodium chloride (n = 113 or sodium bicarbonate (n = 107 before and after contrast dye administration. The intervention were "A" group received 1 ml/kg/hour of normal saline solution, starting 12 hours before and continuing 12 hours after iohexol contrast. "B" group received 3 ml/kg of sodium bicarbonate solution (150 mEq/L one hour prior to procedure and then drip rate was decreased to 1 ml/kg/hour until 6 hours post procedure. Our main outcome measure was change in serum creatinine. Results: The mean creatinine value after the procedure was 1.26 mg/dL in the saline group and 1.22 mg/dL in the bicarbonate group (mean difference: 0.036; CI 95%: -0.16 to 0.23, p = 0.865. The diagnosis of contrast-induced nephropathy, defined by increase in serum creatinine on 25% or more within 2 days after administration of radiographic contrast, was done in twelve patients (12% in the bicarbonate group and eighth patients (7.1% in the saline group (RR: 1.68, CI 95%: 0.72 to 3.94. Conclusion: Our investigation showed that there were no differences between normal saline solution (extended infusion vs. bicarbonate solution for nephroprotection.

  3. Magnesium bicarbonate as an in situ uranium lixiviant

    International Nuclear Information System (INIS)

    In the subsurface solution mining of mineral values, especially uranium, in situ, magnesium bicarbonate leaching solution is used instead of sodium, potassium and ammonium carbonate and bicarbonates. The magnesium bicarbonate solution is formed by combining carbon dioxide with magnesium oxide and water. The magnesium bicarbonate lixivant has four major advantages over prior art sodium, potassium and ammonium bicarbonates

  4. EFFECTS OF SODIUM BICARBONATE INGESTION ON SWIM PERFORMANCE IN YOUTH ATHLETES

    Directory of Open Access Journals (Sweden)

    Jozef Langfort

    2009-03-01

    Full Text Available The purpose of this study was to evaluate the effect of oral administration of sodium bicarbonate (300 mg·kg-1 b.w. on swim performance in competitive, (training experience of 6.6 ± 0.6 years youth, (15.1 ± 0.6 years male swimmers. The subjects completed a test trial, in a double blind fashion, on separate days, consisting of 4 x 50m front crawl swims with a 1st minute passive rest interval twice, on two occasions: after ingestion of bicarbonate or placebo, 72 hours apart, at the same time of the day. Blood samples were drawn from the finger tip three times during each trial; upon arrival to the laboratory, 60 min after ingestion of placebo or the sodium bicarbonate solution and after the 4 x 50m test, during the 1st min of recovery. Plasma lactate concentration, blood pH, standard bicarbonate and base excess were evaluated. The total time of the 4 x 50 m test trial improved from 1.54.28 to 1.52.85s, while statistically significant changes in swimming speed were recorded only during the first 50m sprint (1.92 vs. 1.97 m·s-1, p < 0.05. Resting blood concentration of HCO-3 increased following the ingestion of sodium bicarbonate from 25.13 to 28.49 mM (p < 0.05. Sodium bicarbonate intake had a statistically significant effect on resting blood pH (7.33 vs. 7.41, p < .05 as well as on post exercise plasma lactate concentration (11.27 vs. 13.06 mM, p < 0.05. Collectively, these data demonstrate that the ingestion of sodium bicarbonate in youth athletes is an effective buffer during high intensity interval swimming and suggest that such a procedure can be used in youth athletes to increase training intensity as well as swimming performance in competition at distances from 50 to 200 m

  5. Unusual radiolytic behavior of neptunium ions in aqueous bicarbonate solutions

    International Nuclear Information System (INIS)

    Behavior of neptunium ions in carbonate and bicarbonate aqueous solutions saturated with air, oxygen or argon during gamma radiation (60Co) by doses up to 3 kGy at dose rates 10 and 25 Gy/min was studied by the method of spectrophotometry. It is shown that in neptunium (5) bicarbonate solution nearly complete (95%) neptunium ion oxidation occurs under the effect of radiation, whereas no oxidation is observed in carbonate solution. Radiation-chemical yield of neptunium (5) oxidation and stationary concentration of neptunium (6) ions depend on concentration of bicarbonate-ions. Explanation to the results obtained is made from the viewpoint of potential radiolytic reactions

  6. Radiolysis of aqueous solutions of ammonium bicarbonate over a large dose range

    DEFF Research Database (Denmark)

    Draganic, Z.D.; Negrón-Mendoza, A.; Sehested, K.; Vujosevic, S.I.; Navarro-Gonzales, R.; Albarran-Sanchez, M.G.; Draganic, I.G.

    1991-01-01

    Oxygen-free aqueous solutions of 0.05 mol dm-3 ammonium and sodium bicarbonate were studied after receiving various doses of Co-60 gammas (0.01-400 kGy) or 0.5-20 Gy pulses of 10 Mev electrons. Formate and oxalate were found to be the main radiolytic products, in addition to trace amounts of form...

  7. Efficacy of sodium bicarbonate as anaesthetic for yellow seahorse, Hippocampus kuda (Bleeker, 1852)

    Digital Repository Service at National Institute of Oceanography (India)

    Pawar, H.B.; Ingole, B.S.; Sreepada, R.A.

    , 8, 10, 12, 14, 16, 18, 20, 25, 30, 40 and 50g L-1 concentrations of sodium bicarbonate. It was observed that very high dose of sodium bicarbonate (more than 30g L-1) was needed to completely anesthetise adult seahorses...

  8. Transformation of Sodium Bicarbonate and CO2 into Sodium Formate over NiPd Nanoparticle Catalyst

    Science.gov (United States)

    Wang, Mengnan; Zhang, Jiaguang; Yan, Ning

    2013-09-01

    The present research systematically investigated, for the first time, the transformation of sodium bicarbonate and CO2 into sodium formate over a series of Ni based metal nanoparticles (NPs). Ni NPs and eight NiM (M stands for a second metal) NPs were prepared by a facile wet chemical process and then their catalytic performance were evaluated in sodium bicarbonate hydrogenation. Bimetallic NiPd NPs with a composition of 7:3 were found to be superior for this reaction, which are more active than both pure Ni and Pd NPs. Hot filtration experiment suggested the NPs to be the truly catalytic active species and kinetic analysis indicated the reaction mechanism to be different than most homogeneous catalysts. The enhanced activity of the bimetallic nanoparticles may be attributed to their smaller size and improved stability.

  9. Anodic deposition of Np(7) compounds from bicarbonate solutions

    International Nuclear Information System (INIS)

    Presented are several results of electrochemical oxidation of Np(6) up to Np(7) in pure carbonate solutions. It is shown that Np can be oxidated electrochemically up to Np(7) on platinum anode at current density of 1.5-20 ma/cm2 and at room temperature. Np(7) solutions in bicarbonate solutions of alkali metal with excessive concentration of bicarbonate in solution have been used as electrolyte. At anode potentials higher than 1.3 V an intensive oxidation of Np(6) up to Np(7) takes place, Np(7), producing, being separated from the solution in the form of hard soluble compound with cation of alkali metal. Anodic oxidation of neptunium up to seven-valent state in bicarbonate solutions can be a convinient way of electrosynthesis of Np(7) solid compounds

  10. Sodium bicarbonate intake improves high-intensity intermittent exercise performance in trained young men

    DEFF Research Database (Denmark)

    Krustrup, Peter; Ermidis, Georgios; Mohr, Magni

    2015-01-01

    Background Sodium bicarbonate intake has been shown to improve exercise tolerance, but the effects on high-intensity intermittent exercise are less clear. Thus, the aim of the present study was to determine the effect of sodium bicarbonate intake on Yo-Yo intermittent recovery level 2 test perfor......-intensity intermittent exercise performance is improved by prior intake of sodium bicarbonate in trained young men, with concomitant elevations in blood alkalosis and peak blood lactate levels, as well as lowered rating of perceived exertion....

  11. A study of the catalytic role of a gold electrode in the electrochemical activation of four macrolide antibiotics in sodium bicarbonate solution

    Directory of Open Access Journals (Sweden)

    Milka L. Avramov Ivi?

    2010-07-01

    Full Text Available Using the cyclic voltammetry, it has been shown that hydrogen evolution at a gold electrode is necessary in the electrochemical activation of azithromycin dihydrate and erythromycin A. After four hours of the potential holding at –1.2 V vs. SCE, the pH of the electrolyte has been changed from 8.40 to 8.96; from 8.40 to 8.77 in the presence of erythromycin A, and from 8.40 to 9.18 in the presence of azithromycin, indicating the reaction of the hydrogen species with antibiotics. This effect has been confirmed by using the phenolphthalein indicator and by analysing colours of the solutions by UV-Vis, as well as by FTIR spectroscopy. Under the identical experimental conditions at the gold electrode, in contrast to azithromycin dihydrate and erythromycin A, roxithromycin and midecamycin electroactivity promotion has been obtained during the first forward sweep starting from the area of a double layer region.

  12. Sodium bicarbonate in-duct injection with sodium sulfate recovery for SO2/NOx control

    International Nuclear Information System (INIS)

    Dry sodium injection with sodium bicarbonate has been used commercially at industrial sites since the mid 1980's. In the past three years, five full scale commercial demonstrations have been completed on electric utility coal fired units. Up to 75% SO2 removal with 0-40% NOx removal has been achieved on units equipped with ESPs. Recent slip stream studies have proven up to 90% SO2 removal and 25% NOx removal when injection is ahead of a baghouse. If dry sodium bicarbonate sorbent injection technology is used prior to a retrofitted baghouse, but after an existing ESP the sodium sulfate by-product/flyash mixture in the baghouse is over 90% Na2SO4. Simple filtration and crystallization will yield a high value 99% + pure Na2SO4 for sale. In this application, no liquid discharge occurs and potentially no solids discharge, since flyash recovered from the filter is either recycled to the boiler with the coal stream or reinjected into the boiler. EPA IAPCS model Version 4 is modified to project costs for this SO2/NOx removal technology when couples with Na2SO4 recovery. In this paper an example is used to show hardware requirements, consumables accountability, by-product recovery rates, capital costs and levelized costs

  13. A Literature Review of the Use of Sodium Bicarbonate for the Treatment of QRS Widening.

    Science.gov (United States)

    Bruccoleri, Rebecca E; Burns, Michele M

    2016-03-01

    Sodium bicarbonate is a well-known antidote for tricyclic antidepressant (TCA) poisoning. It has been used for over half a century to treat toxin-induced sodium channel blockade as evidenced by QRS widening on the electrocardiogram (ECG). The purpose of this review is to describe the literature regarding electrophysiological mechanisms and clinical use of this antidote after poisoning by tricyclic antidepressants and other agents. This article will also address the literature supporting an increased serum sodium concentration, alkalemia, or the combination of both as the responsible mechanism(s) for sodium bicarbonate's antidotal properties. While sodium bicarbonate has been used as a treatment for cardiac sodium channel blockade for multiple other agents including citalopram, cocaine, flecainide, diphenhydramine, propoxyphene, and lamotrigine, it has uncertain efficacy with bupropion, propranolol, and taxine-containing plants. PMID:26159649

  14. Studies on the kinetics of UO2 dissolution in carbonate-bicarbonate medium using sodium hypochlorite as oxidant

    International Nuclear Information System (INIS)

    The dissolution of UO2 in carbonate-bicarbonate solutions containing sodium hypochlorite as an oxidant has been investigated. The effect of temperature, sodium hypochlorite concentration and stirring speed was examined. In the temperature range of 303 to 318 K, the leaching reaction displayed linear kinetics. Apparent activation energy obtained from the differential approach was found to be 57 kJ mol-1. This relatively high activation energy value indicates a chemically controlled behavior of UO2 dissolution. The order of reaction with respect to sodium hypochlorite concentration was found to be unity. (author). 18 refs., 6 figs

  15. Metabolic attributes, yield and stability of milk in Jersey cows fed diets containing sodium citrate and sodium bicarbonate

    Directory of Open Access Journals (Sweden)

    Marcelo Tempel Stumpf

    2013-05-01

    Full Text Available The objective of this work was to evaluate the inclusion of sodium citrate and sodium bicarbonate in the diet of lactating Jersey cows, and its effects on the metabolic attributes, productivity and stability of milk. We evaluated urinary pH, levels of glucose and urea in blood, body weight, body condition score, milk yield, milk stability (ethanol test, and milk physicochemical properties of 17 cows fed diets containing sodium citrate (100 g per cow per day, sodium bicarbonate (40 g per cow per day or no additives. Assessments were made at the 28th and 44th days. Supply of sodium citrate or bicarbonate has no influence on the metabolic attributes, productivity, body weight, and body condition score of the cows, neither on the composition and stability of milk.

  16. Some aspects of the electrochemical behaviour of mild steel in carbonate/bicarbonate solutions

    International Nuclear Information System (INIS)

    The electrochemical behaviour of mild steel in aqueous solutions of sodium carbonate/sodium bicarbonate (600 ppm) has been investigated using potentiodynamic polarization. In the pre-passive region three well-defined peaks are observed associated to reduction peaks corresponding to Fe(II) and Fe(III) species. A transpassive anodic peak is also observed being attributed to Fe(VI) species showing, in sweep reversal experiments, an associated reduction peak and an increase in the peak associated to the reduction of Fe(III) species. The characterization of the transpassive peak will be subject of further publication. (author)

  17. Effects of combined creatine and sodium bicarbonate supplementation on repeated sprint performance in trained men.

    Science.gov (United States)

    Barber, James J; McDermott, Ann Y; McGaughey, Karen J; Olmstead, Jennifer D; Hagobian, Todd A

    2013-01-01

    Creatine and sodium bicarbonate supplementation independently increase exercise performance, but it remains unclear whether combining these 2 supplements is more beneficial on exercise performance. The purpose of this study was to evaluate the impact of combining creatine monohydrate and sodium bicarbonate supplementation on exercise performance. Thirteen healthy, trained men (21.1 ± 0.6 years, 23.5 ± 0.5 kg·m(-2), 66.7 ± 5.7 ml·(kg·m)(-1) completed 3 conditions in a double-blinded, crossover fashion: (a) Placebo (Pl; 20 g maltodextrin + 0.5 g·kg(-1) maltodextrin), (b) Creatine (Cr; 20 g + 0.5 g·kg(-1) maltodextrin), and (c) Creatine plus sodium bicarbonate (Cr + Sb; 20 g + 0.5 g·kg(-1) sodium bicarbonate). Each condition consisted of supplementation for 2 days followed by a 3-week washout. Peak power, mean power, relative peak power, and bicarbonate concentrations were assessed during six 10-second repeated Wingate sprint tests on a cycle ergometer with a 60-second rest period between each sprint. Compared with Pl, relative peak power was significantly higher in Cr (4%) and Cr + Sb (7%). Relative peak power was significantly lower in sprints 4-6, compared with that in sprint 1, in both Pl and Cr. However, in Cr + Sb, sprint 6 was the only sprint significantly lower compared with sprint 1. Pre-Wingate bicarbonate concentrations were significantly higher in Cr + Sb (10%), compared with in Pl and Cr, and mean concentrations remained higher after sprint 6, although not significantly. Combining creatine and sodium bicarbonate supplementation increased peak and mean power and had the greatest attenuation of decline in relative peak power over the 6 repeated sprints. These data suggest that combining these 2 supplements may be advantageous for athletes participating in high-intensity, intermittent exercise. PMID:23254493

  18. Effect of sodium bicarbonate pretreatment on barium coating of mucosa during double contrast barium meal

    International Nuclear Information System (INIS)

    The radiographic pattern of the areae gastricae is produced by barium lying in the intersecting furrows of the gastric mucosal surface. However, if the mucus layer on the gastric mucosa is thick, it interferes with the barium coating of the areae gastricae during double contrast barium meal. As sodium bicarbonate decreases the viscosity of mucus and thus may make the gastric mucus layer thinner, it was evaluated as a pretreatment agent in a routine double contrast upper-gastrointestinal study to improve the visualization of the areae gastricae. In a single blind study, 53 of 106 patients took sodium bicarbonate water mixtures at bedtime the day before and on the morning of the examination. According to the results of the present study mucolysis induced by the used doses of sodium bicarbonate does not significantly affect micromucosal visualization during double-contrast barium meal. (orig.)

  19. Sodium bicarbonate intake improves high-intensity intermittent exercise performance in trained young men

    DEFF Research Database (Denmark)

    Krustrup, Peter; Ermidis, Georgios; Mohr, Magni

    2015-01-01

    Background Sodium bicarbonate intake has been shown to improve exercise tolerance, but the effects on high-intensity intermittent exercise are less clear. Thus, the aim of the present study was to determine the effect of sodium bicarbonate intake on Yo-Yo intermittent recovery level 2 test....... Peak heart rate reached at exhaustion was 197 ± 3 and 195 ± 3 bpm in SBC and CON, respectively, with no difference between conditions. RPE was 7 % lower (P = 0.003) in SBC than in CON after 440 m, but similar at exhaustion (19.3 ± 0.2 and 19.5 ± 0.2). Conclusion In conclusion, high-intensity...... intermittent exercise performance is improved by prior intake of sodium bicarbonate in trained young men, with concomitant elevations in blood alkalosis and peak blood lactate levels, as well as lowered rating of perceived exertion....

  20. Effect of sodium bicarbonate on the prevention of contrast induced nephropathy in patients undergoing coronary angiography

    International Nuclear Information System (INIS)

    Contrast induced nephropathy (CIN) remains a common complication of coronary angiography (CAG) and is associated with significant morbidity and mortality. Although a previous study reported pretreatment with sodium bicarbonate is more effective than sodium chloride for prophylaxis of CIN, this has not been a universal finding and the long-term effects of sodium bicarbonate on CIN have not been studied before. We performed a prospective, single-center, randomized trial to investigate whether CIN can be avoided by sodium bicarbonate in patients with chronic renal failure. Eighty patients with chronic renal failure (defined as serum creatinine concentration (SCr), >1.1 mg per deciliter), who were undergoing CAG, were enrolled in this study. We assigned them to either sodium chloride plus sodium bicarbonate (Group B: n=35) or sodium chloride alone (Group C: n=45). In all patients, an infusion of sodium chloride of 1 ml/kg per hour was given between 12 hours before and after the procedure. In Group B, sodium bicarbonate infusion of 1 ml/kg per hour continued from 3 hours before procedure to 6 hours after procedure, changing from sodium chloride at 1 ml/kg per hour. SCr was measured at baseline, day 1, day 2 and 1 month after the procedure. CIN was defined as a 25% increase in SCr from baseline value, or an absolute increase of at least 0.5 mg/dl, which appears within 2 days after CAG. No differences in age, sex and contrast volume were observed between the two groups. SCr at baseline was not significantly different in the two groups (Group B: 1.41±0.32 versus Group C: 1.50±0.38 mg/dl). SCr at day 2 was significantly lower in Group B than Group C (1.44±0.38 versus 1.60±0.5 mg/dl, p<0.05) and 1 month (1.28±0.27 versus 1.49±0.55 mg/dl, p<0.05). CIN occurred in 9 patients (20%) in Group C but in only 2 (6%) in Group B (p=0.03). Sodium chloride plus sodium bicarbonate is more effective than sodium chloride alone for prophylaxis of CIN and can help retain long-term renal function. (author)

  1. Radiolysis of aqueous solutions of ammonium bicarbonate over a large dose range

    International Nuclear Information System (INIS)

    Oxygen-free aqueous solutions of 0.05 mol dm-3 ammonium and sodium bicarbonate were studied after receiving various doses of 60Co gammas (0.01-400 kGy) or 0.5-20 Gy pulses of 10 Mev electrons. Formate and oxalate were found to be the main radiolytic products, in addition to trace amounts of formaldehyde and an unidentified polymer. A large initial yield of formate in the ?-radiolysis, G(HCOO-) = 2.2, is due to the reaction COO- + HCO3-? HCOO- +CO3-. The efficiency of organic synthesis within the large dose range studied is low and is explained by efficient pathways leading to the reformation of bicarbonate, where the reaction COO- + CO3- is particularly significant. (author)

  2. CRACK2 - Modelling calcium carbonate deposition from bicarbonate solution in cracks in concrete

    International Nuclear Information System (INIS)

    The numerical CRACK2 model simulates precipitation of calcite from calcium bicarbonate solution (e.g. groundwater) passing through cracks in concrete or other cementitious materials. A summary of experimental work is followed by a detailed description of the model. Hydroxyl ions are transported by diffusion in pore systems in columns of cementitious materials. The hydroxyl is precipitating calcite from a flow of bicarbonate solution in a crack connecting the ends of a row of such columns. The cementitious material is simulated as calcium hydroxide mixed with inert material but with sodium hydroxide dissolved in the pore solution. Diffusive migration of cesium as radioactive isotope is also considered. Electrical interaction of the migrating ions is taken into account. Example calculations demonstrate effects of parameter variations on distribution of precipitated calcite in the crack and on the composition of the outflowing solution, which can be compared directly with experimental results. Leaching behavior of sodium can be used to tune the model to experimental observations. The calcite is mostly precipitated on top of the original crack surface and may under certain circumstances fill the crack. The produced thin layers of low porosity calcite act as a diffusion barrier limiting contact between cement and solution. Pore closure mechanisms in such layers are discussed. Implications for safety assessment of radioactive waste disposal are shortly mentioned. The model is also relevant for conventional uses of concrete. (au)

  3. Formation of a sodium bicarbonate cluster in the structure of sodium-substituted hydroxyapatite

    Science.gov (United States)

    Tkachenko, M. V.; Kamzin, A. S.

    2015-02-01

    Ceramic sodium-substituted carbonated hydroxyapatite has been synthesized using the method of the solid-phase reaction in the temperature range of 640-820°C in water vapor. It has been established that substitutions of Ca2+ ions in the cation and anion subsystems with Na+ ions and the PO{4/3-} and OH- groups with CO{3/2-} ions lead to a considerable acceleration of the shrinkage and synthesis of dense ceramics at substantially lower temperatures than in the case of unsubstituted hydroxyapatite. Sintering in water vapor leads to densification of carbonate groups in channel positions, which induces the appearance of orderings of A2 and B2 types (bands with wave numbers 867 and 865 cm-1 in IR spectra, respectively) as well as the protonation of carbonate groups both in A and B sites and the formation of sodium bicarbonate clusters (856 and 859 cm-1) in addition to carbonate ordering of A1 and B1 types (879 and 872 cm-1).

  4. Control of blue mold of apple by combining controlled atmosphere, antagonist mixtures and sodium bicarbonate

    Science.gov (United States)

    'Golden Delicious' apples were wound-inoculated with Penicillium expansum, treated with various combinations of sodium bicarbonate and two antagonists, and stored in air or controlled atmosphere (1.4% O2, 3% CO2). The fruit were stored for 2 or 4 months at 1°C. The antagonists survived and their p...

  5. Diphenhydramine Overdose with Intraventricular Conduction Delay Treated with Hypertonic Sodium Bicarbonate and IV Lipid Emulsion

    OpenAIRE

    Amin Abdi; Emily Rose; Michael Levine

    2014-01-01

    Diphenhydramine toxicity commonly manifests with antimuscarinic features, including dry mucous membranes, tachycardia, urinary retention, mydriasis, tachycardia, and encephalopathy. Severe toxicity can include seizures and intraventricular conduction delay. We present here a case of a 23-year-old male presenting with recurrent seizures, hypotension and wide complex tachycardia who had worsening toxicity despite treatment with sodium bicarbonate. The patient was ultimately treated with intrave...

  6. Sodium bicarbonate-based hydration prevents contrast-induced nephropathy: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Tamhane Umesh

    2009-05-01

    Full Text Available Abstract Background Contrast-induced nephropathy is the leading cause of in-hospital acute renal failure. This side effect of contrast agents leads to increased morbidity, mortality, and health costs. Ensuring adequate hydration prior to contrast exposure is highly effective at preventing this complication, although the optimal hydration strategy to prevent contrast-induced nephropathy still remains an unresolved issue. Former meta-analyses and several recent studies have shown conflicting results regarding the protective effect of sodium bicarbonate. The objective of this study was to assess the effectiveness of normal saline versus sodium bicarbonate for prevention of contrast-induced nephropathy. Methods The study searched MEDLINE, EMBASE, Cochrane databases, International Pharmaceutical Abstracts database, ISI Web of Science (until 15 December 2008, and conference proceedings for randomized controlled trials that compared normal saline with sodium bicarbonate-based hydration regimen regarding contrast-induced nephropathy. Random-effects models were used to calculate summary odds ratios. Results A total of 17 trials including 2,633 subjects were pooled. Pre-procedural hydration with sodium bicarbonate was associated with a significant decrease in the rate of contrast-induced nephropathy (odds ratios 0.52; 95% confidence interval 0.34–0.80, P = 0.003. Number needed to treat to prevent one case of contrast-induced nephropathy was 16 (95% confidence interval 10–34. No significant differences in the rates of post-procedure hemodialysis (P = 0.20 or death (P = 0.53 was observed. Conclusion Sodium bicarbonate-based hydration was found to be superior to normal saline in prevention of contrast-induced nephropathy in this updated meta-analysis.

  7. Photochemical oxidation of americium(3) in bicarbonate-carbonate solutions saturated with N2O

    International Nuclear Information System (INIS)

    The influence of UV radiation on 1.1x10-4 mol/l Am(3) in bicarbonate-carbonate solutions of sodium and potassium saturated with N2O was studied by spectrographic method. In all the cases Am(4) was formed as a primary product. Initial rate of Am(4) accumulation remains stable in solutions up to HCO3- or HCO3-+CO32- concentration of approximately 1.5 mol/l, but it decreases in case of their higher concentration. In solutions with pH 8.4-10 Am(4) disproportionates at a slow rate and the method suggested permits attaining practically 100% yield of it

  8. Effects of Cheap Antidotes; Sodium Bicarbonate and Magnesium Sulfate in Organophosphorous Poisoning

    International Nuclear Information System (INIS)

    Organophosphorous (OP) compounds have been used as pesticides and chemical warfare nerve agents. Despite administration of well known antidotes (atropine and oximes), morbidity and mortality of OP poisoning were still high. Besides, oximes are very expensive and not available in most developing countries. It was thus aimed to study the effects of cheap available antidotes; sodium bicarbonate and magnesium sulfate in OP poisoning. In addition to the standard antidotal treatment, out of 117 patients (63M, 47F) aged 25.2 ± 9.5 years with moderate to severe acute OP pesticide poisoning 59 were given sodium bicarbonate 5 mEq/kg in 60 min. followed by 5-6 mEq/kg/day to obtain arterial blood pH of 7.45 to 7.55. Arterial blood pH increased significantly (p less than 0.01) to 7.48 ± 0.05 compared to the controls (7.32 ± 0.06). Morbidity based on hospitalization days reduced significantly (p less than 0.05) from 5.62 ± 3.4 in the controls to 3.1 ± 2.6 days in the sodium bicarbonate group. Total atropine dose was also significantly (p less than 0.05) lower in the test group. Mortality was lower, but not significantly due to the low numbers (5 and 2 of the controls and test group, respectively). Sodium bicarbonate appeared to be effective and could be added to the treatment regime of OP poisoning. Magnesium sulfate was administered four gram intravenously only for the first 24 hr of hospitalization day for the patients with moderate to severe OP poisoning in a pilot study. The results were promising and thus further investigations are continued.(author)

  9. The effect of sodium bicarbonate on intracellular pH using 31P-MR spectroscopy

    International Nuclear Information System (INIS)

    This report deals with the effects of sodium bicarbonate on the intracellular pH of the brain and cerebral blood flow (CBF); five normal volunteers were studied. Intracellular pH and CBF were measured by phosphorus 31 magnetic resonance spectroscopy (31P-MRS) and stable xenon computed tomography (Xe-CT), respectively. Each individual received 7% sodium bicarbonate (3.5 ml/kg body weight), infused intravenously over a 15-min period. Intracellular pH, CBF, and physiological parameters were determined before and after the injection. Intracellular pH was significantly decreased and CBF was increased. Among the physiological parameters, the hematocrit was significantly decreased and arterial pressure of carbon dioxide (PaCO2), increased. These results suggest that increasing CO2 contributes to the decrease in intracellular pH. In conclusion, three factors increase CBF during the administration of sodium bicarbonate to humans: arterial dilatation in response to carbon dioxide; decrease of the hematocrit, and intracellular cerebral acidosis. (author)

  10. Ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise

    DEFF Research Database (Denmark)

    Marriott, Matthaus; Krustrup, Peter; Mohr, Magni

    2015-01-01

    BACKGROUND: Caffeine and sodium bicarbonate ingestion have been suggested to improve high-intensity intermittent exercise, but it is unclear if these ergogenic substances affect performance under provoked metabolic acidification. To study the effects of caffeine and sodium bicarbonate on intense...... intermittent exercise performance and metabolic markers under exercise-induced acidification, intense arm-cranking exercise was performed prior to intense intermittent running after intake of placebo, caffeine and sodium bicarbonate. METHODS: Male team-sports athletes (n = 12) ingested sodium bicarbonate (Na......HCO3; 0.4 g.kg(-1) b.w.), caffeine (CAF; 6 mg.kg(-1) b.w.) or placebo (PLA) on three different occasions. Thereafter, participants engaged in intense arm exercise prior to the Yo-Yo intermittent recovery test level-2 (Yo-Yo IR2). Heart rate, blood lactate and glucose as well as rating of perceived...

  11. Effect of sodium bicarbonate supplementation on feed intake, digestibility, digesta kinetics, nitrogen balance and ruminal fermentation in young fattening lambs

    OpenAIRE

    Bodas, Raúl; Frutos, Pilar; Giráldez, Francisco Javier; Hervás, Gonzalo; López, Secundino

    2009-01-01

    [EN] Twenty-two Merino lambs (average weight=15.3 kg) were used to study the effects of inclusion of sodium bicarbonate in the concentrate on feed intake, digestibility, rate of passage, nitrogen balance and ruminal fermentation in vivo and in vitro. Lambs were allocated to two experimental groups receiving concentrate and 20 g kg-1 sodium bicarbonate (group Bic) or concentrate alone (group Control). Both groups received barley straw ad libitum. Faeces and urine were collected for...

  12. Ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise

    OpenAIRE

    Marriott, Matthaus; Krustrup, Peter; Mohr, Magni

    2015-01-01

    BACKGROUND: Caffeine and sodium bicarbonate ingestion have been suggested to improve high-intensity intermittent exercise, but it is unclear if these ergogenic substances affect performance under provoked metabolic acidification. To study the effects of caffeine and sodium bicarbonate on intense intermittent exercise performance and metabolic markers under exercise-induced acidification, intense arm-cranking exercise was performed prior to intense intermittent running after intake of placebo,...

  13. Ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise

    DEFF Research Database (Denmark)

    Marriott, Matthaus; Krustrup, Peter; Mohr, Magni

    2015-01-01

    BACKGROUND: Caffeine and sodium bicarbonate ingestion have been suggested to improve high-intensity intermittent exercise, but it is unclear if these ergogenic substances affect performance under provoked metabolic acidification. To study the effects of caffeine and sodium bicarbonate on intense intermittent exercise performance and metabolic markers under exercise-induced acidification, intense arm-cranking exercise was performed prior to intense intermittent running after intake of placebo, ca...

  14. Sodium bicarbonate absorption and anabolism by detatched root of young paddy rice, corn and wheat plants

    International Nuclear Information System (INIS)

    This work is aimed at investigating species-to-species difference in the capability of absorption and anabolism through the root and examining the effects of sodium bicarbonate on the capability. Roots detatched from young plants of paddy rice, corn and wheat are used as the samples. The respiratory rate and anabolic rate of the detatched roots are measured by using the 14C tracer. It is found that paddy rice whows the greatest initial anabolic rate, while the rates of corn and wheat are 14 - 30 % of that of paddy rice. The initial anabolic rate is almost independent of the concentration of sodium bicarbonate. The initial absorption rate is greatest in paddy rice, followed by corn (30 - 78 %) and wheat (16 - 21 %). It is also shown that paddy rice has the greatest capability both in anabolism and absorption. The anabolism and absorption capabilities of corn are 17 - 29 % and 31 - 80 % of those of paddy rice, respectively. The corresponding values of wheat are 16 - 38 % and 24 - 66 %. Sidium bicarbonate has little effect on the anabolism capability, while the absorption capability is affected above a high concentration of 50 mM. (Nogami, K.)

  15. Sodium bicarbonate intake improves high-intensity intermittent exercise performance in trained young men

    DEFF Research Database (Denmark)

    Krustrup, Peter; Ermidis, Georgios

    2015-01-01

    Background Sodium bicarbonate intake has been shown to improve exercise tolerance, but the effects on high-intensity intermittent exercise are less clear. Thus, the aim of the present study was to determine the effect of sodium bicarbonate intake on Yo-Yo intermittent recovery level 2 test performance in trained young men. Method Thirteen men aged 23?±?1 year (height: 180?±?2 cm, weight: 78?±?3 kg; VO2max: 61.3?±?3.3 mlO2?·?kg?1?·?min?1; means?±?SEM) performed the Yo-Yo intermittent recovery level 2 test (Yo-Yo IR2) on two separate occasions in randomized order with (SBC) and without (CON) prior intake of sodium bicarbonate (0.4 g?·?kg?1 body weight). Heart rate and rating of perceived exertion (RPE) were measured during the test and venous blood samples were taken frequently. Results Yo-Yo IR2 performance was 14 % higher (P?=?0.04) in SBC than in CON (735?±?61 vs 646?±?46 m, respectively). Blood pH and bicarbonate were similar between trials at baseline, but higher (P?=?0.003) immediately prior to the Yo-Yo IR2 test in SBC than in CON (7.44?±?0.01 vs 7.32?±?0.01 and 33.7?±?3.2 vs 27.3?±?0.6 mmol?·?l?1, respectively). Blood lactate was 0.9?±?0.1 and 0.8?±?0.1 mmol?·?l?1 at baseline and increased to 11.3?±?1.4 and 9.4?±?0.8 mmol?·?l?1 at exhaustion in SBC and CON, respectively, being higher (P?=?0.03) in SBC. Additionally, peak blood lactate was higher (P?=?0.02) in SBC than in CON (11.7?±?1.2 vs 10.2?±?0.7 mmol?·?l?1). Blood glucose, plasma K+ and Na+ were not different between trials. Peak heart rate reached at exhaustion was 197?±?3 and 195?±?3 bpm in SBC and CON, respectively, with no difference between conditions. RPE was 7 % lower (P?=?0.003) in SBC than in CON after 440 m, but similar at exhaustion (19.3?±?0.2 and 19.5?±?0.2). Conclusion In conclusion, high-intensity intermittent exercise performance is improved by prior intake of sodium bicarbonate in trained young men, with concomitant elevations in blood alkalosis and peak blood lactate levels, as well as lowered rating of perceived exertion.

  16. Exhaust gas purification with sodium bicarbonate. Analysis and evaluation; Abgasreinigung mit Natriumhydrogencarbonat. Analyse und Bewertung

    Energy Technology Data Exchange (ETDEWEB)

    Quicker, Peter; Rotheut, Martin; Schulten, Marc [RWTH Aachen Univ. (Germany). Lehr- und Forschungsgebiet Technologie der Energierohstoffe (TEER); Athmann, Uwe [dezentec ingenieurgesellschaft mbH, Essen (Germany)

    2013-03-01

    The dry exhaust gas cleaning uses sodium bicarbonate in order to absorb acid components of exhaust gases such as sulphur dioxide or hydrochloric acid. Recently, sodium and calcium based adsorbents are compared with respect to their economic and ecologic options. None of the investigations performed considered decidedly practical experiences from the system operation such as differences in the management, availability, personnel expenditure and maintenance expenditure. Under this aspect, the authors of the contribution under consideration report on exhaust gas cleaning systems using sodium carbonate as well as lime adsorbents. The operators of these exhaust gas cleaning systems were questioned on their experiences, and all relevant operational data (consumption of additives, consumption of energy, emissions, standstill, maintenance effort) were recorded and evaluated at a very detailed level.

  17. Sodium bicarbonate injection: a small-plant SO sub 2 /NO sub x option

    Energy Technology Data Exchange (ETDEWEB)

    Darmstaedter, E. (NaTec Resources Inc. (USA). Environmental Systems Division)

    1990-12-01

    The sodium bicarbonate injection process provides a cost effective alternative to flue gas desulfurization for smaller power plants. EPRI and NaTec Resources have been conducting demonstrations on coal-fired utility boilers. 90% SO{sub 2} reduction was achieved in EPRI's High-Sulfur Test Centre 4 MW pilot HYPAS installation near Barker, NY. During 1990 Public Service Company of Colorado and NaTec completed a two-phase commercial demonstration for continuous SO{sub 2}/NO{sub x} control on Cherokee Unit 1 to determine levels of urea and injection locations for urea and sodium bicarbonate to minimise NO{sub 2} and NH{sub 3} emissions while maintaining a high level of SO{sub 2} reduction. Methods for sodium sulphate by-product recovery/sale are described - these are higher value than those from the limestone process. Costs for the whole process, driven by sorbent costs, work out typically for a dry sorbent injection/HYPAS system at $610/ton SO{sub 2} removed. 11 refs., 5 figs., 1 tab.

  18. Additive effects of beta-alanine and sodium bicarbonate on upper-body intermittent performance

    OpenAIRE

    Tobias, Gabriel; Benatti, Fabiana Braga; de Salles Painelli, Vitor; Roschel, Hamilton; Gualano, Bruno; Sale, Craig; Harris, Roger C.; Lancha, Antonio Herbert; Artioli, Guilherme Gianinni

    2013-01-01

    We examined the isolated and combined effects of beta-alanine (BA) and sodium bicarbonate (SB) on high-intensity intermittent upper-body performance in judo and jiu-jitsu competitors. 37 athletes were assigned to one of four groups: (1) placebo (PL)+PL; (2) BA+PL; (3) PL+SB or (4) BA+SB. BA or dextrose (placebo) (6.4 g day?1) was ingested for 4 weeks and 500 mg kg?1 BM of SB or calcium carbonate (placebo) was ingested for 7 days during the 4th week. Before and after 4 weeks of supplementation...

  19. Diphenhydramine Overdose with Intraventricular Conduction Delay Treated with Hypertonic Sodium Bicarbonate and IV Lipid Emulsion

    Directory of Open Access Journals (Sweden)

    Amin Abdi

    2014-11-01

    Full Text Available Diphenhydramine toxicity commonly manifests with antimuscarinic features, including dry mucous membranes, tachycardia, urinary retention, mydriasis, tachycardia, and encephalopathy. Severe toxicity can include seizures and intraventricular conduction delay. We present here a case of a 23-year-old male presenting with recurrent seizures, hypotension and wide complex tachycardia who had worsening toxicity despite treatment with sodium bicarbonate. The patient was ultimately treated with intravenous lipid emulsion therapy that was temporally associated with improvement in the QRS duration. We also review the current literature that supports lipid use in refractory diphenhydramine toxicity. [West J Emerg Med. 2014;15(7:–0.

  20. CRACK2. Modelling calcium carbonate deposition from bicarbonate solutions in cracks in concrete

    DEFF Research Database (Denmark)

    Brodersen, Knud Erik

    2003-01-01

    The numerical CRACK2 model simulates precipitation of calcite from calcium bicarbonate solution (e.g. groundwater) passing through cracks in concrete or other cementitious materials. A summary of experimental work is followed by a detailed description ofthe model. Hydroxyl ions are transported by diffusion in pore systems in columns of cementitious materials. The hydroxyl is precipitating calcite from a flow of bicarbonate solution in a crack connecting the ends of a row of such columns. Theceme...

  1. Degradation of hydroxyapatite in vivo and in vitro requires osteoclastic sodium-bicarbonate co-transporter NBCn1

    DEFF Research Database (Denmark)

    Riihonen, Riikka; Nielsen, Søren; Väänänen, H Kalervo; Laitala-Leinonen, Tiina; Kwon, Tae-Hwan

    2010-01-01

    Dissolution of the inorganic bone matrix releases not only calcium and phosphate ions, but also bicarbonate. Electroneutral sodium-bicarbonate co-transporter (NBCn1) is expressed in inactive osteoclasts, but its physiological role in bone resorption has remained unknown. We show here that NBCn1, encoded by the SLC4A7 gene, is directly involved in bone resorption. NBCn1 protein was specifically found at the bone-facing ruffled border areas, and metabolic acidosis increased NBCn1 expression in rat...

  2. Sodium bicarbonate intake improves high-intensity intermittent exercise performance in trained young men

    DEFF Research Database (Denmark)

    Krustrup, Peter; Ermidis, Georgios; Mohr, Magni

    2015-01-01

    performance in trained young men. Method Thirteen men aged 23?±?1 year (height: 180?±?2 cm, weight: 78?±?3 kg; VO2max: 61.3?±?3.3 mlO2?·?kg?1?·?min?1; means?±?SEM) performed the Yo-Yo intermittent recovery level 2 test (Yo-Yo IR2) on two separate occasions in randomized order with (SBC) and without (CON......) prior intake of sodium bicarbonate (0.4 g?·?kg?1 body weight). Heart rate and rating of perceived exertion (RPE) were measured during the test and venous blood samples were taken frequently. Results Yo-Yo IR2 performance was 14 % higher (P?=?0.04) in SBC than in CON (735?±?61 vs 646?±?46 m, respectively......-intensity intermittent exercise performance is improved by prior intake of sodium bicarbonate in trained young men, with concomitant elevations in blood alkalosis and peak blood lactate levels, as well as lowered rating of perceived exertion....

  3. Effect of Beta alanine and sodium bicarbonate supplementation on repeated-sprint performance.

    Science.gov (United States)

    Ducker, Kagan J; Dawson, Brian; Wallman, Karen E

    2013-12-01

    This study aimed to investigate if combining beta alanine (BA) and sodium bicarbonate (NaHCO3) supplementation could lead to enhanced repeated-sprint performance in team-sport athletes, beyond what is possible with either supplement alone. Participants (n = 24) completed duplicate trials of a repeated-sprint test (3 sets; 6 × 20 m departing every 25 seconds, 4 minutes active recovery between sets) and were then allocated into 4 groups as follows: BA only (n = 6; 28 days BA, acute sodium chloride placebo); NaHCO3 only (n = 6; 28 days glucose placebo, acute NaHCO3); BA/NaHCO3 (n = 6; 28 days BA, acute NaHCO3); placebo only (n = 6; 28 days glucose placebo, acute sodium chloride placebo), then completed duplicate trials postsupplementation. Sodium bicarbonate alone resulted in moderate effect size (d = 0.40-0.71) and "likely" and "very likely" benefit for overall total sprint times (TST) and for each individual set and for first sprint (sets 2 and 3) and best sprint time (sets 2 and 3). Combining BA and NaHCO3 resulted in "possible" to "likely" benefits for overall TST and for sets 2 and 3. First sprint (set 3) and best sprint time (sets 2 and 3) also showed "likely" benefit after this trial. The BA and placebo groups showed no differences in performance after supplementation. In conclusion, these results indicate that supplementation with acute NaHCO3 improved repeated-sprint performance more than either a combination of NaHCO3 and BA or BA alone. PMID:23524361

  4. A spectroelectrochemical study of the technetium(IV)/technetium(III) couple in bicarbonate solutions

    International Nuclear Information System (INIS)

    Spectroelectrochemistry at an optically transparent electrode, in conjunction with controlled potential coulometry, has been used to study the Tc(IV)/Tc(III) redox couple in aqueous bicarbonate solutions. The complexation provided by bicarbonate/carbonate ions was found to stabilize both Tc(IV) and Tc(III). The uv-visible absorption spectra for technetium(III) and technetium(IV) carbonate complexes are described. The redox potential for the Tc(IV)/Tc(III) couple, as well as the number of electrons, the number of carbonate groups, and the number of hydroxyl groups exchanged during the redox process in bicarbonate media are reported

  5. Excess sodium bicarbonate in the diet and its effect on Leghorn chickens.

    Science.gov (United States)

    Davison, S; Wideman, R F

    1992-09-01

    1. A commercial 62-week-old layer flock experienced an acute drop in egg production and an increase in shell-less egg production within 2 days of consuming feed erroneously formulated to contain over 30 g/kg instead of 3 g/kg sodium bicarbonate (NaHCO3). Other symptoms included increased water consumption, diarrhoea and increased mortality associated with visceral gout. 2. An experiment was conducted to assess the responses of hens under controlled conditions. Twenty Dekalb XL Single Comb White Leghorn hens (50 weeks old) were placed in individual cages, having ad libitum access to water from trough waterers. Ten hens were fed the TEST (High NaHCO3) feed for one week (Test group), and ten hens remained on normal commercial layer ration (Control group). 3. Hens in the Test group had high water consumption and watery droppings, but egg production and mortality were not affected. Physiological evaluations indicated the Test feed caused metabolic alkalosis. Plasma sodium, urine pH and urinary sodium excretion were increased, and glomerular filtration rates were decreased in the Test group. 4. These physiological effects are consistent with known responses to excess sodium intake in domestic fowl. The reduced egg production and increased mortality caused by the Test feed under commercial conditions may be related to more severe dehydration experienced by hens in multi-bird cages supplied by cup-type watering systems. PMID:1327426

  6. Effects of sodium bicarbonate and 1,25-dihydroxy-cholecalciferol on calcium and phosphorus balances in the rat

    International Nuclear Information System (INIS)

    Metabolic balance studies were undertaken to determine whether sodium bicarbonate (NaHCO3) supplements (4.5 mmol/day) altered 7-day cumulative calcium (Ca) phosphorus (P) balances in growing rats consuming either a basal diet providing 0.6% Ca and 0.3% P, or this diet plus 1,25-dihydroxycholecalciferol [40 ng 1,25(OH)2D3/day]. Feeding bicarbonate lowered urinary Ca but raised fecal Ca so that Ca balance became less positive. However, 1,25(OH)2D3 increased net absorption of Ca and P to the same degree when given to control rats and rats consuming bicarbonate. Nevertheless, bicarbonate-fed rats had lower net Ca absorption than controls, even when treated with high doses of 1,25(OH)2D3. Changes in net Ca absorption induced by bicarbonate may occur at a point in the gut distal to the duodenum since duodenal 45Ca absorption was decreased by bicarbonate feeding. The present results show that bicarbonate consumption depressed net Ca absorption in the rat. The effect appears to be independent of changes in 1,25(OH)2D3 metabolism because it is manifest in animals receiving high doses of 1,25(OH)2D3, which stimulate alimentary Ca absorption maximally, and because bicarbonate-fed rats are able to respond normally to exogenous 1,25(OH)2D3 by increasing their net absorption of Ca and P. In view of this demonstration that NaHCO3 supplements elevate fecal Ca loss in the rat, it is suggested that studies should be undertaken to determine whether bicarbonate exerts similar adverse effects on Ca balance in humans

  7. Control of blue mold decay of apple during commercial controlled atmosphere storage with yeast antagonists and sodium bicarbonate

    Science.gov (United States)

    A mixture of two yeast antagonists, Metschnikowia pulcherrima and Cryptococcus laurentii, originally isolated from apples and having superior biocontrol activity against blue mold of apple over individual application of these yeasts, were used in combination with sodium bicarbonate (SBC) in a pilot ...

  8. Effects of potential and concentration of bicarbonate solution on stress corrosion cracking of annealed carbon steel

    International Nuclear Information System (INIS)

    Effects of potential and concentration of bicarbonate on stress corrosion cracking (SCC) of annealed SM 400 B carbon steel has been investigated in bicarbonate solutions at 343 K. The surface of annealed specimen had decarburized layer of about 0. 5 mm thickness. A potentiostatic slow strain rate testing apparatus equipped with a charge coupled device camera system was employed to evaluate SCC susceptibility from the viewpoint of the crack behavior. In a constant bicarbonate concentration of 1 M, cracks were observed in the potential range from -800 to 600 mVAg/AgCl. and especially, the initiation and the propagation of the cracks were accelerated at -600 mV. At a constant potential of -600 mV, cracks were observed in the concentration range from 0.001 to 1 M, and the initiation and the propagation of the cracks were suppressed as the concentration decreased. Polarization curves for the decarburized surface were measured with two different scan rates. High SCC susceptibility may be expected in the potential range where the difference between the two current densities is large. It was found in this system that the potential with the maximum difference in the current density was -600 mV for 1 M bicarbonate solution, and the potential increased with a decrease in the concentration of bicarbonate. This means that an applied potential of -600 mV provides the highest SCC susceptibility for 1 M bicarbonate solution, and that the SCC susceptibility decreases as the concentration decreases. These findings support the dependence of the actual SCC behavior on the potential and the concentration of bicarbonate. (author)

  9. Toxopathology of gout induced in laying pullets by sodium bicarbonate toxicity.

    Science.gov (United States)

    Mubarak, M; Sharkawy, A A

    1999-10-01

    A total of 60, 3-week-old, laying pullets were used in the present experiment. The exposed birds received excess sodium bicarbonate (SB) in their drinking water for 35 days at the levels of: 2 g/l (0.2%), 7.5 g/l (0.75%), 20 g/l (2%) and 40 g/l (4%). All birds were subjected to pathological and toxicological examination. Birds of the 0.75% and 2%-groups developed gross picture of visceral gout, while birds of 4%-group showed acute kidney damage without manifesting visceral urate deposition. Erythrocytic count, packed cell volume (PCV), and hemoglobin (Hb) levels were all increased in the exposed birds. There were dose-related increments in the serum level of sodium (Na(+)). Serum levels of chloride (Cl(-)), and potassium (K(+)) were relatively decreased in some cases. Serum levels of uric acid were increased in a dose-related pattern. Blood pH of the treated birds was shifted toward the alkaline side. Microscopic examination revealed significant renal changes in birds manifesting visceral gout and these changes included urate deposits associated with tubular necrotic changes. Some birds in the third group (2%) developed urate granulomas (tophi) in their renal interstitium. It was concluded that development of gout in birds may be related to a state of metabolic alkalosis which is associated with significant changes of the electrolyte balance. PMID:21781931

  10. On photochemical reactions of Am(5) in bicarbonate-carbonate solutions

    International Nuclear Information System (INIS)

    The influence of UV radiation on Am(5) in solutions of sodium carbonate-bicarbonate with pH 9.00-11.40 has been studied by spectrophotometric method. At pH 9-10 a mixture of Am(4)+Am(6) is formed, but the degree of Am(5) transformation does not exceed 60-70%. The reaction order in terms of Am(5) is close to 1. Quantum yield of the reaction during photolysis by light with ? = 337 nm is estimated as 0.003. With increase in pH the reaction rate and degree of Am(5) transformation decrease. The reaction starts with absorption of UV light quantum by Am(5) carbonate complex. It is assumed that the reaction first stage is electron transfer either from water molecule to Am(5) in coordination sphere of excited carbonate complex of Am(5) or between two Am(5) ions in excimer, consisting of excited and non-excited carbonate complexes of Am(5). 10 refs., 2 figs

  11. Facile and Efficient Acetylation of Primary Alcohols and Phenols with Acetic Anhydride Catalyzed by Dried Sodium Bicarbonate

    Directory of Open Access Journals (Sweden)

    Fulgentius Nelson Lugemwa

    2013-12-01

    Full Text Available A variety of primary alcohols and phenols were reacted with acetic anhydride at room temperature in the presence of sodium bicarbonate to produce corresponding esters in good to excellent yields. The acetylation of 4-nitrobenzyl alcohol was also carried out using other bicarbonates and carbonates. The reaction in the presence of cesium bicarbonate and lithium carbonate gave 4-nitrobenzyl acetate in excellent yield, while in the presence of Na2CO3, K2CO3, Cs2CO3, or KHCO3 the yield was in the range of 80%–95%. Calcium carbonate and cobaltous carbonate did not promote the acetylation of 4-ntirobenzyl alcohol using acetic anhydride. The acetylation of 4-nitrobenzyl alcohol was carried out using ethyl acetate, THF, toluene, diethyl ether, dichloromethane and acetonitrile, and gave good yields ranging from 75%–99%. Toluene was the best solvent for the reaction, while diethyl ether was the poorest.

  12. Comparative solubilisation of potassium carbonate, sodium bicarbonate and sodium carbonate in hot dimethylformamide: application of cylindrical particle surface-controlled dissolution theory.

    OpenAIRE

    Forryan, CL; Compton, RG; Klymenko, OV; Brennan, CM; Taylor, CL; Lennon, M.

    2006-01-01

    A surface-controlled dissolution of cylindrical solid particles model is applied to potassium carbonate, sodium bicarbonate and sodium carbonate in dimethylformamide at elevated temperatures. Previously published data for the dissolution of potassium carbonate is interpreted assuming a cylindrical rather than a spherical shape of the particles, the former representing a closer approximation to the true shape of the particles as revealed by scanning electron microscopy. The dissolution kinetic...

  13. The Effects of Novel Ingestion of Sodium Bicarbonate on Repeated Sprint Ability.

    Science.gov (United States)

    Miller, Peter; Robinson, Amy L; Sparks, S Andy; Bridge, Craig A; Bentley, David J; McNaughton, Lars R

    2016-02-01

    Miller, P, Robinson, AL, Sparks, SA, Bridge, CA, Bentley, DJ, and McNaughton, LR. The effects of novel ingestion of sodium bicarbonate on repeated sprint ability. J Strength Cond Res 30(2): 561-568, 2016-This work examined the influence of an acute dose of sodium bicarbonate (NaHCO3) on buffering capacity and performance during a repeated sprint ability (RSA) protocol. Eleven (mean ± SD: age 24.6 ± 6.1 years; mass 74.9 ± 5.7 kg; height 177.2 ± 6.7 cm) participated in the study, undertaking 4 test sessions. On the first visit to the laboratory, each participant ingested 300 mg·kg of NaHCO3 (in 450 ml of flavored water) and blood samples were obtained at regular intervals to determine the individual times peak pH and HCO3. In subsequent visits, participants ingested 300 mg·kg of NaHCO3, 270 mg·kg body mass (BM) of NaCI, or no drink followed by a RSA cycling protocol (10 × 6 seconds sprints with 60 seconds recovery), which commenced at each individuals predetermined ingestion peak pH response time. Blood samples were obtained before exercise and after the first, fifth, and 10th sprint to determine the blood pH, HCO3, and lactate (La) responses. Total work completed during the repeated sprint protocol was higher (p ? 0.05) in the NaHCO3 condition (69.8 ± 11.7 kJ) compared with both the control (59.6 ± 12.2 kJ) and placebo (63.0 ± 8.3 kJ) conditions. Peak power output was similar (p > 0.05) between the 3 conditions. Relative to the control and placebo conditions, NaHCO3 ingestion induced higher (p ? 0.05) blood pH and HCO3 concentrations before exercise and during the bouts, and higher lactate concentrations (p ? 0.05) after the final sprint. Results suggest that NaHCO3 improves the total amount of work completed during RSA through enhanced buffering capacity. PMID:26815179

  14. Ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise

    DEFF Research Database (Denmark)

    Marriott, Matthaus; Krustrup, Peter

    2015-01-01

    BACKGROUND: Caffeine and sodium bicarbonate ingestion have been suggested to improve high-intensity intermittent exercise, but it is unclear if these ergogenic substances affect performance under provoked metabolic acidification. To study the effects of caffeine and sodium bicarbonate on intense intermittent exercise performance and metabolic markers under exercise-induced acidification, intense arm-cranking exercise was performed prior to intense intermittent running after intake of placebo, caffeine and sodium bicarbonate. METHODS: Male team-sports athletes (n?=?12) ingested sodium bicarbonate (NaHCO3; 0.4 g.kg(-1) b.w.), caffeine (CAF; 6 mg.kg(-1) b.w.) or placebo (PLA) on three different occasions. Thereafter, participants engaged in intense arm exercise prior to the Yo-Yo intermittent recovery test level-2 (Yo-Yo IR2). Heart rate, blood lactate and glucose as well as rating of perceived exertion (RPE) were determined during the protocol. RESULTS: CAF and NaHCO3 elicited a 14 and 23% improvement (P?sodium bicarbonate administration improved Yo-Yo IR2 performance and lowered perceived exertion after intense arm cranking exercise, with greater overall effects of sodium bicarbonate intake.

  15. Gout induced by intoxication of sodium bicarbonate in Korean native broilers.

    Science.gov (United States)

    Ejaz, Sohail; Kim, Bum Seok; Lim, Chae Woong

    2005-01-01

    Gout is a metabolic disorder that results in hyperuricemia and the deposition of positively birefringent monosodium urate crystals in various parts of the body. Intoxication of sodium bicarbonate (SBC) for 35 days in Korean native broilers was investigated. Sixty birds, aged 2 weeks, divided into 5 groups were exposed to excess SBC: 2 g/L (group A), 7.5 g/L (group B), 20 g/L (group C), 40 g/L (group D). Toxicopathological examination of all exposed birds revealed the manifestation of visceral and articular gout in group C, while birds of group D showed acute kidney damage with manifestation of excessive visceral gout. Interestingly, few birds in group D also showed signs of rare condition of acute articular gout. Dose-dependent increments in erythrocytic count, hematocrit values, and hemoglobin levels of the exposed birds were observed. Hypernatremia, hyperuricemia, hypokalemia, and hypochloremia were common findings among exposed birds. Microscopic examination of birds that manifested visceral gout revealed significant urate deposit, tubular necrosis, and tophi formation in renal interstitium. These findings provide a pathophysiological link that SBC intoxication may support hyperuricemia, which is an independent risk factor for gout and other renal dysfunctions. Further study is required to delineate the effect of lowering uric acid on progression of gout and other renal diseases. PMID:15865264

  16. Optimization of sodium bicarbonate injection for acid scrubbing in hospital waste incineration plant

    International Nuclear Information System (INIS)

    Optimization of sodium bicarbonate (NaHCO3) injection for acid hydrochloric (HCl) scrubbing was conducted on a hospital waste incineration plant. The plant employs a rotary kiln system having burning capacity of 350 kg/h hospital waste (average calorific value of 17.4 MJ/kg) and is operated on a 24 hr/ day basis. Currently, NaHCO3 injection rate is 25 kg/h as recommended by manufacturer to meet the Department of Environment (DOE) standard emission limit of 200 mg/Nm3 HCl. Testing of HCl emission at various injection rates of 25, 20, 15 and 10 kg/ h results in HCl final concentration in the range of 0.58-7.13, 5.63-7.74, 0.07-2.99 and 3-28 mg/Nm3 respectively. The results showed that NaHCO3 injection rate as low as 10 kg/ h could still meet the HCl stipulated emission limit. Economic comparison between 25 and 10 kg/ h injection rates showed that total saving on NaHCO3 and disposal of fly ash was RM 22,000 per month (equivalent to saving RM 260,000 per year) when using 10 kg/ h injection rate. It was concluded from the study that optimum injection rate would not only save cost and reduce wastage but also reduce bag house loading rate and prolong the life span of filter bags. (author)

  17. In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.; Skaar, Don

    2014-01-01

    Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO3 rise to more than 1500?mg/L (also expressed as >1245?mg HCO3 (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800?m to 1200?m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed.

  18. Combination of Kluyveromyces marxianus and sodium bicarbonate for controlling green mold of citrus fruit.

    Science.gov (United States)

    Geng, Peng; Chen, Shaohua; Hu, Meiying; Rizwan-Ul-Haq, Muhammad; Lai, Kaiping; Qu, Fei; Zhang, Yanbo

    2011-12-01

    Biocontrol efficacy of an antagonistic yeast Kluyveromyces marxianus was evaluated individually or in combination with sodium bicarbonate (SBC) against green mold of citrus fruit caused by Penicillium digitatum. Their effects on postharvest quality of citrus fruit were also investigated. The results indicated that the antagonistic activity of K. marxianus at 1×10? CFU/mL on green mold of citrus fruit was enhanced by 2% SBC treatment. In artificial inoculation trials, disease control after 3 and 6 days, respectively, with the mixture of K. marxianus and 2% SBC (18.33%, 58.33%) was significantly improved over that obtained with K. marxianus (41.67%, 70.00%) or SBC (43.33%, 81.67%) alone. The combination of K. marxianus with SBC was as effective as the imazalil treatment in natural infection trials, which gave about 90% control of green mold. Addition of 2% SBC significantly stimulated the growth of K. marxianus in citrus fruit wounds after 72 h. Moreover, K. marxianus, SBC and their combination did not impair quality parameters including weight loss, fruit firmness, total soluble solids, titratable acidity and ascorbic acid at 4 °C for 30 days followed by 20 °C for 15 days. These results suggested that the use of SBC is a useful approach to improve the efficacy of K. marxianus for the postharvest green mold of citrus fruit. PMID:21920618

  19. The chronic toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.

    2014-01-01

    Sodium bicarbonate (NaHCO3) is the principal salt in coal bed natural gas produced water from the Powder River Structural Basin, Wyoming, USA, and concentrations of up to 3000?mg NaHCO3/L have been documented at some locations. No adequate studies have been performed to assess the chronic effects of NaHCO3 exposure. The present study was initiated to investigate the chronic toxicity and define sublethal effects at the individual organism level to explain the mechanisms of NaHCO3 toxicity. Three chronic experiments were completed with fathead minnows (Pimephales promelas), 1 with white suckers (Catostomus commersoni), 1 with Ceriodaphnia dubia, and 1 with a freshwater mussel, (Lampsilis siliquoidea). The data demonstrated that approximately 500?mg NaHCO3/L to 1000?mg NaHCO3/L affected all species of experimental aquatic animals in chronic exposure conditions. Freshwater mussels were the least sensitive to NaHCO3 exposure, with a 10-d inhibition concentration that affects 20% of the sample population (IC20) of 952?mg NaHCO3/L. The IC20 for C. dubia was the smallest, at 359?mg NaHCO3/L. A significant decrease in sodium–potassium adenosine triphosphatase (Na+/K+ ATPase) together with the lack of growth effects suggests that Na+/K+ ATPase activity was shut down before the onset of death. Several histological anomalies, including increased incidence of necrotic cells, suggested that fish were adversely affected as a result of exposure to >450?mg NaHCO3/L.

  20. Sodium bicarbonate for the prevention of contrast induced nephropathy: A meta-analysis of published clinical trials

    Energy Technology Data Exchange (ETDEWEB)

    Kunadian, Vijayalakshmi, E-mail: kunadianvijay@aol.com [Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne Hospitals, NHS Foundation Trust/Newcastle University, Newcastle upon Tyne (United Kingdom); Zaman, Azfar, E-mail: Azfar.Zaman@nuth.nhs.uk [Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne Hospitals, NHS Foundation Trust/Newcastle University, Newcastle upon Tyne (United Kingdom); Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne (United Kingdom); Spyridopoulos, Ioakim [Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne Hospitals, NHS Foundation Trust/Newcastle University, Newcastle upon Tyne (United Kingdom); Institute of Human Genetics, Newcastle University, Newcastle upon Tyne (United Kingdom); Qiu, Weiliang [Channing Laboratory, Department of Medicine, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA, United States of America (United States)

    2011-07-15

    Background: Contrast induced nephropathy (CIN) is a serious but rare complication following contrast based procedures. Sodium bicarbonate (NaHCO{sub 3}) has been postulated to prevent CIN by various mechanisms. However, the outcomes following sodium bicarbonate administration to prevent CIN have been inconsistent. Methods: A meta-analysis of published randomized clinical trials to determine if the administration of sodium bicarbonate is superior to sodium chloride among patients with chronic renal failure undergoing catheterization and interventional procedures in preventing CIN was performed. Results: Data were combined across seven published clinical trials consisting of 1734 patients. There were no significant differences in the baseline characteristics between the NaHCO{sub 3} and NaCl groups except patients in the bicarbonate group were heavier (P = 0.04). The odds ratio (OR) for the development of contrast nephropathy for NaHCO{sub 3} versus NaCl was 0.33 (95% confidence interval [CI] 0.16-0.69; P = 0.003). Heterogeneity and publication bias were detectable with P-values 0.01 and 0.0005 respectively. There was no difference between the NaHCO{sub 3} group and the NaCl group in the occurrence of death [OR 0.6; 95% CI (0.26-1.41); P = 0.24], congestive heart failure [OR 0.85; 95% CI (0.32-2.24); P = 0.74] and the requirement for renal replacement therapy [OR 0.56; 95% CI (0.22-1.41); P = 0.22]. Conclusion: This meta-analysis demonstrates that based on currently available randomized trials, the administration of NaHCO{sub 3} is superior to the administration of NaCl alone in the prevention of CIN among patients with moderate to severe chronic kidney disease. However, further controlled clinical trials are needed due to significant study heterogeneity and publication bias.

  1. Sodium bicarbonate for the prevention of contrast induced nephropathy: A meta-analysis of published clinical trials

    International Nuclear Information System (INIS)

    Background: Contrast induced nephropathy (CIN) is a serious but rare complication following contrast based procedures. Sodium bicarbonate (NaHCO3) has been postulated to prevent CIN by various mechanisms. However, the outcomes following sodium bicarbonate administration to prevent CIN have been inconsistent. Methods: A meta-analysis of published randomized clinical trials to determine if the administration of sodium bicarbonate is superior to sodium chloride among patients with chronic renal failure undergoing catheterization and interventional procedures in preventing CIN was performed. Results: Data were combined across seven published clinical trials consisting of 1734 patients. There were no significant differences in the baseline characteristics between the NaHCO3 and NaCl groups except patients in the bicarbonate group were heavier (P = 0.04). The odds ratio (OR) for the development of contrast nephropathy for NaHCO3 versus NaCl was 0.33 (95% confidence interval [CI] 0.16-0.69; P = 0.003). Heterogeneity and publication bias were detectable with P-values 0.01 and 0.0005 respectively. There was no difference between the NaHCO3 group and the NaCl group in the occurrence of death [OR 0.6; 95% CI (0.26-1.41); P = 0.24], congestive heart failure [OR 0.85; 95% CI (0.32-2.24); P = 0.74] and the requirement for renal replacement therapy [OR 0.56; 95% CI (0.22-1.41); P = 0.22]. Conclusion: This meta-analysis demonstrates that based on currently available randomized trials, the administration of NaHCO3 is superior to the administration of NaCl alone in the prevention of CIN among patients with moderate to severe chronic kidney disease. However, further controlled clinical trials are needed due to significant study heterogeneity and publication bias.

  2. Aldosterone stimulates the cardiac sodium/bicarbonate cotransporter via activation of the g protein-coupled receptor gpr30.

    Science.gov (United States)

    De Giusti, Verónica C; Orlowski, Alejandro; Ciancio, María C; Espejo, María S; Gonano, Luis A; Caldiz, Claudia I; Vila Petroff, Martín G; Villa-Abrille, María C; Aiello, Ernesto A

    2015-12-01

    Some cardiac non-genomic effects of aldosterone (Ald) are reported to be mediated through activation of the classic mineralocorticoid receptor (MR). However, in the last years, it was proposed that activation of the novel G protein-coupled receptor GPR30 mediates certain non-genomic effects of Ald. The aim of this study was to elucidate if the sodium/bicarbonate cotransporter (NBC) is stimulated by Ald and if the activation of GPR30 mediates this effect. NBC activity was evaluated in rat cardiomyocytes perfused with HCO3(-)/CO2 solution in the continuous presence of HOE642 (sodium/hydrogen exchanger blocker) during recovery from acidosis using intracellular fluorescence measurements. Ald enhanced NBC activity (% of ?JHCO3(-); control: 100±5.82%, n=7 vs Ald: 151.88±11.02%, n=5; P<0.05), which was prevented by G15 (GPR30 blocker, 90.53±7.81%, n=7). Further evidence for the involvement of GPR30 was provided by G1 (GPR30 agonist), which stimulated NBC (185.13±18.28%, n=6; P<0.05) and this effect was abrogated by G15 (124.19±10.96%, n=5). Ald- and G1-induced NBC stimulation was abolished by the reactive oxygen species (ROS) scavenger MPG and by the NADPH oxidase inhibitor apocynin. In addition, G15 prevented Ald- and G1-induced ROS production. Pre-incubation of myocytes with wortmannin (PI3K-AKT pathway blocker) prevented Ald- or G1-induced NBC stimulation. In summary, Ald stimulates NBC by GPR30 activation, ROS production and AKT stimulation. PMID:26497404

  3. Additive effects of beta-alanine and sodium bicarbonate on upper-body intermittent performance.

    Science.gov (United States)

    Tobias, Gabriel; Benatti, Fabiana Braga; de Salles Painelli, Vitor; Roschel, Hamilton; Gualano, Bruno; Sale, Craig; Harris, Roger C; Lancha, Antonio Herbert; Artioli, Guilherme Gianinni

    2013-08-01

    We examined the isolated and combined effects of beta-alanine (BA) and sodium bicarbonate (SB) on high-intensity intermittent upper-body performance in judo and jiu-jitsu competitors. 37 athletes were assigned to one of four groups: (1) placebo (PL)+PL; (2) BA+PL; (3) PL+SB or (4) BA+SB. BA or dextrose (placebo) (6.4 g day?¹) was ingested for 4 weeks and 500 mg kg?¹ BM of SB or calcium carbonate (placebo) was ingested for 7 days during the 4th week. Before and after 4 weeks of supplementation, the athletes completed four 30-s upper-body Wingate tests, separated by 3 min. Blood lactate was determined at rest, immediately after and 5 min after the 4th exercise bout, with perceived exertion reported immediately after the 4th bout. BA and SB alone increased the total work done in +7 and 8 %, respectively. The co-ingestion resulted in an additive effect (+14 %, p < 0.05 vs. BA and SB alone). BA alone significantly improved mean power in the 2nd and 3rd bouts and tended to improve the 4th bout. SB alone significantly improved mean power in the 4th bout and tended to improve in the 2nd and 3rd bouts. BA+SB enhanced mean power in all four bouts. PL+PL did not elicit any alteration on mean and peak power. Post-exercise blood lactate increased with all treatments except with PL+PL. Only BA+SB resulted in lower ratings of perceived exertion (p = 0.05). Chronic BA and SB supplementation alone equally enhanced high-intensity intermittent upper-body performance in well-trained athletes. Combined BA and SB promoted a clear additive ergogenic effect. PMID:23595205

  4. Preventive and therapeutic effects of sodium bicarbonate on melamine-induced bladder stones in mice.

    Science.gov (United States)

    Ren, Shu-Ting; Du, Yun-Xia; Xu, Chang-Fu; Zhang, Jiao-Jiao; Mo, Li-Ping; Sun, Ying; Gao, Xiao-Li

    2014-10-01

    The actual preventive and therapeutic effects of alkalinizing urine on melamine-induced bladder stones (cystolith) are not completely known. Using an ideal model, two experiments were conducted in Balb/c mice. The mice were fed a normal diet in controls and a melamine diet in the other groups. The first day was set as experiment-day 1. In "Experiment 1", either low-/mid-/high-dose sodium bicarbonate (SB) or sterile water was administered by intragastric perfusion (once daily) to the mice for 14 days. Relative to the model group, the mean pH of the urine in the SB groups was significantly elevated at 3 h after SB administration, with a significant decrease in cystolith incidence on experiment-day 14. In "Experiment 2", on experiment-day 12, the melamine diet was replaced by a normal diet in 4 groups with melamine withdrawal (MW). Meanwhile, either mid-/high-dose SB or sterile water was administered by intragastric perfusion (once) to the mice in the corresponding groups. On experiment-day 12, after an additional 8 h, the cystolith incidence was significantly reduced in the high-SB, MW + mid-SB and MW + high-SB groups than in the model group. In conclusion, low urinary pH is one of the main determinants of the formation of melamine-associated stones, urinary alkalinization can be achieved by a proper dose of oral SB, and SB acts to prevent and treat melamine-induced cystoliths in mice. PMID:25092435

  5. The Effect of Sodium Bicarbonate in Sports Drink on the Metabolism of Athletes

    Directory of Open Access Journals (Sweden)

    Yanchun Liu

    2015-05-01

    Full Text Available It is known that sodium bicarbonate (NaHCO3 is used by athletes before exercise to delay fatigue and improve performance based on the knowledge that it removes H+ ions from the body through the creation of a metabolic alkalosis state. In this study, the effects of 0.3 g/kg NaHCO3 given orally to athletes and non-athletes before a 600 m race were compared. After resting for 48 h, 0.3 g/kg NaHCO3 was given orally as a 500 mL fruit juice and the same determinations made under the same conditions 2 h later. In the study, the time taken to complete race after the administration of NaHCO3 fell compared to that before its administration in the athletes. The level of HCO3- before the administration of NaHCO3 in the athletes was observed to be higher than after the administration of NaHCO3. A rise in the HLa levels was observed after exercising following the administration of NaHCO3 ’ in the athletes. The differences in the other parameters apart from that in pH were not statistically significant (p<0.01, (p<0.05. In conclusion, it can be said that, use of NaHCO3 at doses low enough not to cause gastrointestinal disturbances is one of the factors that positively affect anaerobic performance in athletes, but this effect is lower than that observed in individuals leading sedentary lives.

  6. Toxicity of Sodium Bicarbonate to Fish from Coal-Bed Natural Gas Production in the Tongue and Powder River Drainages, Montana and Wyoming

    Science.gov (United States)

    U.S. Geological Survey

    2006-01-01

    This study evaluates the sensitivity of aquatic life to sodium bicarbonate (NaHCO3), a major constituent of coal-bed natural gas-produced water. Excessive amounts of sodium bicarbonate in the wastewater from coal-bed methane natural gas production released to freshwater streams and rivers may adversely affect the ability of fish to regulate their ion uptake. The collaborative study focuses on the acute and chronic toxicity of sodium bicarbonate on select fish species in the Tongue and Powder River drainages in southeastern Montana and northeastern Wyoming. Sodium bicarbonate is not naturally present in appreciable concentrations within the surface waters of the Tongue and Powder River drainages; however, the coal-bed natural gas wastewater can reach levels over 1,000 milligrams per liter. Large concentrations have been shown to be acutely toxic to native fish (Mount and others, 1997). In 2003, with funding and guidance provided by the U.S. Environmental Protection Agency, the Montana Fish, Wildlife, and Parks and the U.S. Geological Survey initiated a collaborative study on the potential effects of coal-bed natural gas wastewater on aquatic life. A major goal of the study is to provide information to the State of Montana Water Quality Program needed to develop an aquatic life standard for sodium bicarbonate. The standard would allow the State, if necessary, to establish targets for sodium bicarbonate load reductions.

  7. Corrosion behavior of iron and carbon steel in bicarbonate solution and in ground water

    International Nuclear Information System (INIS)

    Corrosion behavior was studied for iron and carbon steel in bicarbonate solution and in ground water by corrosion potential measurement and electrochemical impedance spectroscopy. Iron and carbon steel were passivated in the air-saturated carbonate media. In 0.1 M NaHCO3 saturated with N2, iron and carbon steel electrodes were in an active state, but their corrosion rates were not much different from air saturated cases. From the AC impedance spectroscopic result, it is suggested that the electrochemical dissolution of iron and carbon steel accompanies an adsorption reaction in the bicarbonate solutions. In ground water, the corrosion rates of iron and carbon steel were evaluated as 5.8 ? m/yr and 0.27 ? m/yr, respectively

  8. The role of sodium bicarbonate in the nucleation of noctilucent clouds

    Directory of Open Access Journals (Sweden)

    J. M. C. Plane

    Full Text Available It is proposed that a component of meteoric smoke, sodium bicarbonate (NaHCO3, provides particularly effective condensation nuclei for noctilucent clouds. This assertion is based on three conditions being met. The first is that NaHCO3 is present at sufficient concentration (±104 cm-3 in the upper mesosphere between 80 and 90 km. It is demonstrated that there is strong evidence for this based on recent laboratory measurements coupled with atmospheric modelling. The second condition is that the thermodynamics of NaHCO3(H2On cluster formation allow spontaneous nucleation to occur under mesospheric conditions at temperatures below 140 K. The Gibbs free energy changes for forming clusters with n = 1 and 2 were computed from quantum calculations using hybrid density functional/Hartree-Fock (B3LYP theory and a large basis set with added polarization and diffuse functions. The results were then extrapolated to higher n using an established dependence of the free energy on cluster size and the free energy for the sublimation of H2O to bulk ice. A 1-dimensional model of sodium chemistry was then employed to show that spontaneous nucleation to form ice particles (n >100 should occur between 84 and 89 km in the high-latitude summer mesosphere. The third condition is that other metallic components of meteoric smoke are less effective condensation nuclei, so that the total number of potential nuclei is small relative to the amount of available H2O. Quantum calculations indicate that this is probably the case for major constituents such as Fe(OH2, FeO3 and MgCO3.

    Key words: Atmospheric composition and structure (aerosols and particles; cloud physics and chemistry; middle atmosphere · composition and chemistry

  9. Scientific Opinion on the safety assessment of the active substances, sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulphate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, for use as active system in food contact materials

    OpenAIRE

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF)

    2014-01-01

    This scientific opinion of EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the active substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, used in mixture which is packed into sachets for absorbing oxygen/carbon dioxide emitting from/into the headspace surrounding packed food. All substances of this formulation have been e...

  10. Structural modifications of the salivary conditioning film upon exposure to sodium bicarbonate: implications for oral lubrication and mouthfeel.

    Science.gov (United States)

    Ash, A; Wilde, P J; Bradshaw, D J; King, S P; Pratten, J R

    2016-03-14

    The salivary conditioning film (SCF) that forms on all surfaces in the mouth plays a key role in lubricating the oral cavity. As this film acts as an interface between tongue, enamel and oral mucosa, it is likely that any perturbations to its structure could potentially lead to a change in mouthfeel perception. This is often experienced after exposure to oral hygiene products. For example, consumers that use dentifrice that contain a high concentration of sodium bicarbonate (SB) often report a clean mouth feel after use; an attribute that is clearly desirable for oral hygiene products. However, the mechanisms by which SB interacts with the SCF to alter lubrication in the mouth is unknown. Therefore, saliva and the SCF was exposed to high ionic strength and alkaline solutions to elucidate whether the interactions observed were a direct result of SB, its high alkalinity or its ionic strength. Characteristics including bulk viscosity of saliva and the viscoelasticity of the interfacial salivary films that form at both the air/saliva and hydroxyapatite/saliva interfaces were tested. It was hypothesised that SB interacts with the SCF in two ways. Firstly, the ionic strength of SB shields electrostatic charges of salivary proteins, thus preventing protein crosslinking within the film and secondly; the alkaline pH (≈8.3) of SB reduces the gel-like structure of mucins present in the pellicle by disrupting disulphide bridging of the mucins via the ionization of their cysteine's thiol group, which has an isoelectric point of ≈8.3. PMID:26883483

  11. Sodium bicarbonate protects uranium-induced acute nephrotoxicity through uranium-decorporation by urinary alkalinization in rats

    OpenAIRE

    Ohmachi, Yasushi; Imamura, Tomomi; Ikeda, Mizuyo; Shishikura, Eriko; Kim, Eunjoo; Kurihara, Osamu; Sakai, Kazuo

    2015-01-01

    To evaluate the effectiveness of sodium bicarbonate (SB) in removing uranium and protecting animals from uranium toxicity, we intramuscularly administered 1 mg/kg of uranyl nitrate to 8-wk-old male SD rats, and 20 min after administration of uranyl nitrate, the animals were given a single oral administration of SB at 0.1, 0.3 or 1 g/kg. The SB treatment at a dose of 0.3 g/kg or more raised the pH of the rats’ urine until 4 h after treatment, and it significantly reduced the uranium amounts in...

  12. The Mn(2+)-bicarbonate complex in a frozen solution revisited by pulse W-band ENDOR.

    Science.gov (United States)

    Potapov, Alexey; Goldfarb, Daniella

    2008-11-17

    The coordination of bicarbonate to Mn (2+) is the simplest model system for the coordination of Mn (2+) to carboxylate residues in a protein. Recently, the structure of such a complex has been investigated by means of X-band pulse EPR (electron paramagnetic resonance) experiments ( Dasgupta, J. ; et al. J. Phys. Chem. B 2006, 110, 5099 ). Based on the EPR results, together with electrochemical titrations, it has been concluded that the Mn (2+) bicarbonate complex consists of two bicarbonate ligands, one of which is monodentate and other bidentate, but only the latter has been observed by the pulsed EPR techniques. The X-band measurements, however, suffer several drawbacks. (i) The zero-field splitting (ZFS) term of the spin Hamiltonian affects the nuclear frequencies. (ii) There are significant contributions from ENDOR (electron nuclear double resonance) lines of the M S not equal +/- (1)/ 2 manifolds. (iii) There are overlapping signals of (23)Na. All these reduce the uniqueness of the data interpretation. Here we present a high-field ENDOR investigation of Mn (2+)/NaH (13)CO 3 in a water/methanol solution that eliminates the above difficulties. Both Davies and Mims ENDOR measurements were carried out. The spectra show that a couple of slightly inequivalent (13)C nuclei are present, with isotropic and anisotropic hyperfine couplings of A iso1 = 1.2 MHz, T perpendicular1 = 0.7 MHz, A iso2 = 1.0 MHz, T perpendicular2 = 0.6 MHz, respectively. The sign of the hyperfine coupling was determined by variable mixing time (VMT) ENDOR measurements. These rather close hyperfine parameters suggest that there are either two distinct, slightly different, carbonate ligands or that there is some distribution in conformation in only one ligand. The distances extracted from T perpendicular1 and T perpendicular2 are consistent with a monodentate binding mode. The monodentate binding mode and the presence of two ligands were further supported by DFT calculations and (1)H ENDOR measurements. Additionally, (23)Na ENDOR resolved at least two types of (23)Na (+) in the Mn (2+)-bicarbonate complex, thus suggesting that the bicarbonate bridges two positively charged metal ions. PMID:18947176

  13. Utilization of sodium bicarbonate for the neutralization of acid components in exhaust gases; Verwendung von Natriumbicarbonat zur Neutralisation saurer Bestandteile in Abgasen

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Thomas [Solvay Chemicals GmbH, Rheinberg (Germany). Technisches Marketing

    2013-03-01

    The SOLVAIR dry process using sodium bicarbonate as absorbent facilitates an uncomplicated and efficient purification of exhaust gases from different processes. The products from exhaust gas purification can be used either directly in a producing process or subsequently to a treatment process in the chemical process. The author of this contribution reports on the utilization of sodium bicarbonate in the neutralisation of pour components in exhaust gases such as hydrochloric acid, sulphur dioxide and nitrous dioxides. Further aspects of this contribution are the energy efficiency and the recycling of reaction products.

  14. Effect of ion concentrations on uranium absorption from sodium carbonate solutions

    International Nuclear Information System (INIS)

    The effect of various ion concentrations on uranium absorption from a sodium carbonate solution by a strong-base, anion resin was investigated in order to help assure an adequate uranium supply for future needs. The studies were conducted to improve the recovery of uranium from in situ leach solutions by ion exchange. The effects of carbonate, bicarbonate, chloride, and sulfate ions were examined. Relatively low (less than 5 g/l) concentrations of chloride, sulfate, and bicarbonate were found to be detrimental to the absorption of uranium. High (greater than 10 g/l) carbonate concentrations also adversely affected the uranium absorption. In addition, the effect of initial resin form was investigated in tests of the chloride, carbonate, and bicarbonate forms; resin form was shown to have no effect on the absorption of uranium

  15. Shock wave synthesis of amino acids from solutions of ammonium formate and ammonium bicarbonate

    Science.gov (United States)

    Suzuki, Chizuka; Furukawa, Yoshihiro; Kobayashi, Takamichi; Sekine, Toshimori; Nakazawa, Hiromoto; Kakegawa, Takeshi

    2015-07-01

    The emergence of life's building blocks, such as amino acids and nucleobases, on the prebiotic Earth was a critical step for the beginning of life. Reduced species with low mass, such as ammonia, amines, or carboxylic acids, are potential precursors for these building blocks of life. These precursors may have been provided to the prebiotic ocean by carbonaceous chondrites and chemical reactions related to meteorite impacts on the early Earth. The impact of extraterrestrial objects on Earth occurred more frequently during this period than at present. Such impacts generated shock waves in the ocean, which have the potential to progress chemical reactions to form the building blocks of life from reduced species. To simulate shock-induced reactions in the prebiotic ocean, we conducted shock-recovery experiments on ammonium bicarbonate solution and ammonium formate solution at impact velocities ranging from 0.51 to 0.92 km/s. In the products from the ammonium formate solution, several amino acids (glycine, alanine, ß-alanine, and sarcosine) and aliphatic amines (methylamine, ethylamine, propylamine, and butylamine) were detected, although yields were less than 0.1 mol % of the formic acid reactant. From the ammonium bicarbonate solution, smaller amounts of glycine, methylamine, ethylamine, and propylamine were formed. The impact velocities used in this study represent minimum cases because natural meteorite impacts typically have higher velocities and longer durations. Our results therefore suggest that shock waves could have been involved in forming life's building blocks in the ocean of prebiotic Earth, and potentially in aquifers of other planets, satellites, and asteroids.

  16. Radiolysis of aqueous solutions of ammonium bicarbonate over a large dose range

    International Nuclear Information System (INIS)

    02-free aqueous solutions of 0.05 mol dm -3 ammonium bicarbonate were studied after receiving various doses of 60Co gammas (0.001-170 Mrd) or krd pulses of 10 MeV electrons. Formate, oxalate, formaldehyde and an unidentified polymer (Mw14000-16000 daltons) were found to be the main radiolytic products. A large initial yield of formate in the γ-radiolysis, G(HCOO-) = 2.2, is due to the reaction CO2- + HCO3- ↔ HC00- + CO3-. The efficiency of organic synthesis within the large dose range studied is low and is explained by efficient pathways to the reformation of bicarbonate, where the reaction CO2- + CO3- is particurlarly significant. Computer fitting of the data obtained in the γ-radiolysis and by pulsed electron beam experiments gives k(CO2- + HCO3-) = (2 ± 0.4)x103 dm3mol-1s-1, k(CO2-+ CO3-) = (5 ± 1)x107 dm3mol-1s-1, k(NH2 + = HCO3-) 4 dm3mol-1s-1 and k(NH2 + CO3-) = (1.5 ± 0.5)x109 dm3mol-1s-1. (author)

  17. Degradation of hydroxyapatite in vivo and in vitro requires osteoclastic sodium-bicarbonate co-transporter NBCn1

    DEFF Research Database (Denmark)

    Riihonen, Riikka; Nielsen, SØren

    2010-01-01

    Dissolution of the inorganic bone matrix releases not only calcium and phosphate ions, but also bicarbonate. Electroneutral sodium-bicarbonate co-transporter (NBCn1) is expressed in inactive osteoclasts, but its physiological role in bone resorption has remained unknown. We show here that NBCn1, encoded by the SLC4A7 gene, is directly involved in bone resorption. NBCn1 protein was specifically found at the bone-facing ruffled border areas, and metabolic acidosis increased NBCn1 expression in rats in vivo. In human hematopoietic stem cell cultures, NBCn1 mRNA expression was observed only after formation of resorbing osteoclasts. To further confirm the critical role of NBCn1 during bone resorption, human hematopoietic stem cells were transduced with SLC4A7 shRNA lentiviral particles. Downregulation of NBCn1 both on mRNA and protein level by lentiviral shRNAs significantly inhibited bone resorption and increased intracellular acidification in osteoclasts. The lentiviral particles did not impair osteoclast survival, or differentiation of the hematopoietic or mesenchymal precursor cells into osteoclasts or osteoblasts in vitro. Inhibition of NBCn1 activity may thus provide a new way to regulate osteoclast activity during pathological bone resorption.

  18. (In)Consistencies in Responses to Sodium Bicarbonate Supplementation: A Randomised, Repeated Measures, Counterbalanced and Double-Blind Study

    Science.gov (United States)

    Froio de Araujo Dias, Gabriela; da Eira Silva, Vinicius; de Salles Painelli, Vitor; Sale, Craig; Giannini Artioli, Guilherme; Gualano, Bruno; Saunders, Bryan

    2015-01-01

    Objectives Intervention studies do not account for high within-individual variation potentially compromising the magnitude of an effect. Repeat administration of a treatment allows quantification of individual responses and determination of the consistency of responses. We determined the consistency of metabolic and exercise responses following repeated administration of sodium bicarbonate (SB). Design and Methods 15 physically active males (age 25±4 y; body mass 76.0±7.3 kg; height 1.77±0.05 m) completed six cycling capacity tests at 110% of maximum power output (CCT110%) following ingestion of either 0.3 g?kg-1BM of SB (4 trials) or placebo (PL, 2 trials). Blood pH, bicarbonate, base excess and lactate were determined at baseline, pre-exercise, post-exercise and 5-min post-exercise. Total work done (TWD) was recorded as the exercise outcome. Results SB supplementation increased blood pH, bicarbonate and base excess prior to every trial (all p ? 0.001); absolute changes in pH, bicarbonate and base excess from baseline to pre-exercise were similar in all SB trials (all p > 0.05). Blood lactate was elevated following exercise in all trials (p ? 0.001), and was higher in some, but not all, SB trials compared to PL. TWD was not significantly improved with SB vs. PL in any trial (SB1: +3.6%; SB2 +0.3%; SB3: +2.1%; SB4: +6.7%; all p > 0.05), although magnitude-based inferences suggested a 93% likely improvement in SB4. Individual analysis showed ten participants improved in at least one SB trial above the normal variation of the test although five improved in none. Conclusions The mechanism for improved exercise with SB was consistently in place prior to exercise, although this only resulted in a likely improvement in one trial. SB does not consistently improve high intensity cycling capacity, with results suggesting that caution should be taken when interpreting the results from single trials as to the efficacy of SB supplementation. Trial Registration ClinicalTrials.gov NCT02474628 PMID:26574755

  19. Low Alloy X100 Pipeline Steel Corrosion and Passivation Behavior in Bicarbonate-Based Solutions of pH 6.7 to 8.9 with Groundwater Anions: An Electrochemical Study

    Science.gov (United States)

    Gadala, Ibrahim M.; Alfantazi, Akram

    2015-07-01

    This research investigates the fundamental corrosion and passivation processes occurring on API-X100 pipeline steels before, during, and after passive layer formation in bicarbonate-based simulated soil solutions of pH 6.7 to 8.9. Free corrosion potentials decrease exponentially with bicarbonate (and pH), owing to increased water and bicarbonate reduction in more alkaline conditions and the coupled iron oxidation reaction. Active corrosion rates at potentials slightly above open circuit potential increase with bicarbonate, until a concentration of 1.68 g L-1 sodium bicarbonate (plus dilute amounts of chlorides/sulfate) at which first signs of film formation appear. Thereon, increased bicarbonate concentration generally decreases current densities and resists ferrous-oxide product formations due to improved iron carbonate formation conditions precipitating more durable passive layers. Potentiodynamic polarization in the anodic regime reveals varying electrochemical processes involving interactions between hydroxide, carbonate, and oxide complexes with ferrous, with diverse pH and potential dependencies. The products of corrosion reactions were investigated by scanning electron microscopy, X-ray diffraction, and/or X-ray photoelectron spectroscopy.

  20. Stress corrosion cracking of nickel alloys in bicarbonate and chloride solutions

    International Nuclear Information System (INIS)

    Alloy 22 is one of the candidates for the manufacture of high level radioactive waste containers. These containers provide services in natural environments characterized by multi-ionics solutions, it is estimated they could suffer three types of deterioration: general corrosion, localized corrosion (crevice corrosion) and stress corrosion cracking (SCC). It has been confirmed that the presence of bicarbonate at temperatures above 60°C and applied potentials around +400 mVSCE are necessary in order to produce cracking, . This susceptibility may be associated to the instability of the passive film formed and to the formation of an anodic current peak in the polarization curves in these media. Until now, it is unclear the role played by each alloying element (Ni, Cr or Mo) in the SCC susceptibility of Alloy 22 in these media The aim of this work is to evaluate the SCC susceptibility of nickel-based alloys in media containing bicarbonate and chloride ions, at high temperature. Slow Strain Rate Testing (SSRT) was conducted to samples of different alloys: 22 (Ni-Cr-Mo), 600 (Ni-Cr-Fe), 800H (Ni-Fe-Cr) y 201 (99.5% Ni).This tests were conducted in 1.1 mol/L NaHCO3 +1.5 mol/L NaCl a 90°C and different applied potentials (+200mVSCE,+300 mVSCE, +400 mVSCE). These results were complemented with those obtained in a previous work, where we studied the anodic electrochemical behavior of nickel base alloys under the same conditions. It was found that alloy 22 showed a current peak in a potential range between +200 mVSCE and +300 mVSCE when immersed in bicarbonate ions containing solutions. This peak was attributed to the presence of chromium in the alloys. The SSRT showed that only alloy 22 has a clear indication of stress corrosion cracking. The current results suggested that the presence of an anodic peak in the polarization curves was not a sufficient condition for cracking. (author)

  1. Carbonic acid ionization and the stability of sodium bicarbonate and carbonate ion pairs to 200 °C - A potentiometric and spectrophotometric study

    Science.gov (United States)

    Stefánsson, Andri; Bénézeth, Pascale; Schott, Jacques

    2013-11-01

    Carbonic acid ionization and sodium bicarbonate and carbonate ion pair formation constants have been experimentally determined in dilute hydrothermal solutions to 200 °C. Two experimental approaches were applied, potentiometric acid-base titrations at 10-60 °C and spectrophotometric pH measurements using the pH indicators, 2-napthol and 4-nitrophenol, at 25-200 °C. At a given temperature, the first and second ionization constants of carbonic acid (K1, K2) and the ion pair formation constants for NaHCO(aq)(K) and NaCO3-(aq)(K) were simultaneously fitted to the data. Results of this study compare well with previously determined values of K1 and K2. The NaHCO(aq) and NaCO3-(aq) ion pair formation constants vary between 25 and 200 °C having values of logK=-0.18 to 0.58 and logK=1.01 to 2.21, respectively. These ion pairs are weak at low-temperatures but become increasingly important with increasing temperature under neutral to alkaline conditions in moderately dilute to concentrated NaCl solutions, with NaCO3-(aq) predominating over CO32-(aq) in ?0.1 M NaCl solution at temperatures above 100 °C. The results demonstrate that NaCl cannot be considered as an inert (non-complexing) electrolyte in aqueous carbon dioxide containing solutions at elevated temperatures.

  2. Effects of sodium bicarbonate on the end-tidal CO2, PaCO2, HCO3-, PH and cerebral blood flow

    International Nuclear Information System (INIS)

    To estimate the quantitative reactivity of cerebral blood flow (CBF), the effects of sodium bicarbonate on the end-tidal CO2, arterial partial pressure of CO2 (PaCO2), HCO3-, pH and CBF were examined. The CBF was measured by 133Xe inhalation method with ring type SPECT (HEADTOME). Activation study with sodium bicarbonate administration was performed after 30 minutes of resting study, and the reactivity of each parameters was investigated. The arterial HCO3- and pH increased with similar reactivity, but PaCO2, end-tidal CO2 and CBF in the non-injured hemisphere changed with irregular reactivity. The excellent correlation between PaCO2 and end-tidal CO2 was vanished by the administration of sodium bicarbonate. The reactivity of CBF did not correlate with reactivity of PaCO2 and end-tidal CO2, but correlated with arterial HCO3- and pH. Thus the measurement of arterial HCO3- and pH may be indispensable to estimate the CBF reactivity with the administration of sodium bicarbonate. (author)

  3. The radiation chemistry of aqueous sodium terephthalate solutions

    International Nuclear Information System (INIS)

    The radiation chemistry of cobalt-60 gamma-irradiated aqueous sodium terephthalate solutions has been studied. In aerated 4 x 10-4M sodium hydroxide solutions, the main products are hydroxyterephthalate (HTA) (G = 0.99 +- 0.01), carbonate (G = 1.31 +- 0.08), and peroxides (G = 2.84 +- 0.04). The HTA and carbonate species are both formed as a result of hydroxyl radical attack and account for approximately 90 per cent of hydroxyl radical reactions. Oxygen needs to be present for efficient conversion of the terephthalate-OH radical adduct to HTA and oxygenation increases G(HTA) above the aerated solution value. G(HTA) is unaffected by changes in terephthalate concentration between 1 x 10-4M and 1 x 10-2M in sodium hydroxide solutions at pH 10. Decreasing the solution pH does however affect G(HTA). In phosphate buffered solutions pH 6.85, G(HTA) is 0.93 +- 0.01 and lower values are obtained with further decrease in solution pH. The lowering of the G(HTA) value is attributed to recombination reactions between the terephthalate-OH radical products and reducing radical products. Experimental evidence supporting the recombination postulate was obtained from the measurement of a parallel decrease in the peroxide yield and the observation of a dose rate effect on G(HTA). Competition kinetic studies with the added solutes carbonate and bicarbonate gave the rate ratios k (OH + TA2-) : k(OH + CO32-) : k(OH + HCO3-) = 1 : 0.105 : 0.0036

  4. Scientific Opinion on the safety assessment of the active substances, sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulphate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, for use as active system in food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-02-01

    Full Text Available This scientific opinion of EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the active substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, used in mixture which is packed into sachets for absorbing oxygen/carbon dioxide emitting from/into the headspace surrounding packed food. All substances of this formulation have been evaluated and approved for use as additives in plastic food contact materials or as food additives. No migration of calcium, iron and sodium ions was detected. No volatile organic compounds other than carbon dioxide were detected at the limit of detection of 0.5 μg/l. The CEF Panel concluded that the use of the substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water does not raise a safety concern when used in oxygen absorber/carbon dioxide emitter systems, in sachets that prevent the physical release of their contents into the food. The sachets are to be placed in the headspace of the packaging and as such may come into occasional contact with the food, e.g. during handling. The sachet should not come into direct contact with liquid foods or foods that have and external aqueous liquid phase on the surface (liquid or exudates.

  5. Effects of Creatine and Sodium Bicarbonate Coingestion on Multiple Indices of Mechanical Power Output During Repeated Wingate Tests in Trained Men.

    Science.gov (United States)

    Griffen, Corbin; Rogerson, David; Ranchordas, Mayur; Ruddock, Alan

    2015-06-01

    This study investigated the effects of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints. Nine well-trained men (age = 21.6 ± 0.9 yr, stature = 1.82 ± 0.05 m, body mass = 80.1 ±12.8 kg) participated in a double-blind, placebo-controlled, counterbalanced, crossover study using six 10-s repeated Wingate tests. Participants ingested either a placebo (0.5 g·kg(-1) of maltodextrin), 20 g·d(-1) of creatine monohydrate + placebo, 0.3 g·kg(-1) of sodium bicarbonate + placebo, or coingestion + placebo for 7 days, with a 7-day washout between conditions. Participants were randomized into two groups with a differential counterbalanced order. Creatine conditions were ordered first and last. Indices of mechanical power output (W), total work (J) and fatigue index (W·s(-1)) were measured during each test and analyzed using the magnitude of differences between groups in relation to the smallest worthwhile change in performance. Compared with placebo, both creatine (effect size (ES) = 0.37-0.83) and sodium bicarbonate (ES = 0.22-0.46) reported meaningful improvements on indices of mechanical power output. Coingestion provided small meaningful improvements on indices of mechanical power output (W) compared with sodium bicarbonate (ES = 0.28-0.41), but not when compared with creatine (ES = -0.21-0.14). Coingestion provided a small meaningful improvement in total work (J; ES = 0.24) compared with creatine. Fatigue index (W·s(-1)) was impaired in all conditions compared with placebo. In conclusion, there was no meaningful additive effect of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints. PMID:25203421

  6. The sodium-bicarbonate cotransporter NBCe2 (slc4a5) expressed in human renal proximal tubules shows increased apical expression under high-salt conditions.

    Science.gov (United States)

    Gildea, John J; Xu, Peng; Carlson, Julia M; Gaglione, Robert T; Bigler Wang, Dora; Kemp, Brandon A; Reyes, Camellia M; McGrath, Helen E; Carey, Robert M; Jose, Pedro A; Felder, Robin A

    2015-12-01

    The electrogenic sodium bicarbonate cotransporter (NBCe2) is encoded by SLC4A5, variants of which have been associated with salt sensitivity of blood pressure, which affects 25% of the adult population. NBCe2 is thought to mediate sodium bicarbonate cotransport primarily in the renal collecting duct, but NBCe2 mRNA is also found in the rodent renal proximal tubule (RPT). The protein expression or function of NBCe2 has not been demonstrated in the human RPT. We validated an NBCe2 antibody by shRNA and Western blot analysis, as well as overexpression of an epitope-tagged NBCe2 construct in both RPT cells (RPTCs) and human embryonic kidney 293 (HEK293) cells. Using this validated NBCe2 antibody, we found NBCe2 protein expression in the RPT of fresh and frozen human kidney slices, RPTCs isolated from human urine, and isolated RPTC apical membrane. Under basal conditions, NBCe2 was primarily found in the Golgi, while NBCe1 was primarily found at the basolateral membrane. Following an acute short-term increase in intracellular sodium, NBCe2 expression was increased at the apical membrane in cultured slices of human kidney and polarized, immortalized RPTCs. Sodium bicarbonate transport was increased by monensin and overexpression of NBCe2, decreased by NBCe2 shRNA, but not by NBCe1 shRNA, and blocked by 2,2'-(1,2-ethenediyl)bis[5-isothiocyanato-benzenesulfonic acid]. NBCe2 could be important in apical sodium and bicarbonate cotransport under high-salt conditions; the implication of the ex vivo studies to the in vivo situation when salt intake is increased remains unclear. Therefore, future studies will examine the role of NBCe2 in mediating increased renal sodium transport in humans whose blood pressures are elevated by an increase in sodium intake. PMID:26447209

  7. Prevention of contrast induced nephropathy with sodium bicarbonate (the PROMEC study) / Prevenção de nefropatia por contraste com bicarbonato de sódio (o estudo PROMEC)

    Scientific Electronic Library Online (English)

    John Fredy, Nieto-Ríos; Wílmar Arley Maya, Salazar; Oscar Mauricio Santos, Sánchez; Janeth Liliana Jaramillo, Ortega; Jorge Ignacio García, Caro; Julián Miguel Aristizabal, Aristizabal; Lina Maria Serna, Higuita; Álvaro García, García; Fabián Alberto Jaimes, Barragán.

    2014-09-01

    Full Text Available Introdução: A nefropatia induzida por contraste é uma complicação comum de procedimentos radiográficos. Medidas diferentes têm sido utilizadas para evitar estes problemas, mas a evidência é controversa. Novos estudos são necessários para esclarecer isso. Investigamos tanto a eficácia quanto a segur [...] ança de uma solução de bicarbonato de sódio em comparação com a solução de cloreto de sódio para evitar nefropatia por contraste em pacientes com ou em risco de desenvolver disfunção renal. Métodos: Estudo prospectivo, randomizado clínico, conduzido em um único centro, entre 01 de maio de 2007 e 8 de fevereiro de 2008. Os pacientes internados em um centro terciário, agendados para passar por um procedimento radiográfico com uso de contraste não iônico., Havia 220 pacientes com níveis de creatinina sérica de pelo menos 1,2 mg/dL (106,1 mmol/L) e/ou diabéticos do tipo 2, que foram escolhidos aleatoriamente para receber uma infusão de cloreto de sódio (n = 113) ou bicarbonato de sódio (n = 107) antes e após a administração do meio de contraste. A intervenção foi: grupo "A" recebeu 1 ml/kg/hora de solução salina normal, começando 12 horas antes e continuando por 12 horas após o uso do contraste iohexol. Os pacientes do grupo "B" receberam 3 ml/kg de uma solução de bicarbonato de sódio (150 mEq/L), 1 hora antes do procedimento e, em seguida, o gotejamento foi reduzido a 1 ml/kg/hora por até 6 horas após o procedimento. Nosso principal indicador de desfecho foi a alteração na creatinina sérica. Resultados: O valor médio da creatinina após o procedimento foi de 1,26 mg/dL no grupo que recebeu a solução salina e 1,22 mg/dL no grupo do bicarbonato (diferença média: 0,036, IC 95%: -0,16 a 0,23, p = 0,865). O diagnóstico da nefropatia induzida por contraste, definida pelo aumento de creatinina no soro em 25% ou mais dentro de 2 dias após a administração de contraste radiográfico, foi realizado em doze pacientes (12%) no grupo do bicarbonato e oitavo pacientes (7,1%) no grupo da solução salina (RR: 1,68, IC 95%: 0,72-3,94). Conclusão: Nossa investigação mostrou que não houve diferença entre soro fisiológico normal (infusão prolongada) contra uma solução de bicarbonato para nefroproteção. Abstract in english Introduction: Contrast-induced nephropathy is a common complication of radiographic procedures. Different measures have been used to avoid this damage, but the evidence is controversial. New investigations are required to clarify it. We investigated the efficacy and safety of sodium bicarbonate sol [...] ution compared with sodium chloride solution to prevent contrast induced nephropathy in patients with or at risk of renal dysfunction. Methods: A prospective, single-center, randomized clinical trial conducted from May 1, 2007 to February 8, 2008. Inpatients in a tertiary center, scheduled to undergo a procedure with the nonionic radiographic contrast agent iohexol. There were 220 patients with serum creatinine levels of at least 1.2 mg/dL (106.1 µmol/L) and/or type 2 diabetics, who were randomized to receive an infusion of sodium chloride (n = 113) or sodium bicarbonate (n = 107) before and after contrast dye administration. The intervention were "A" group received 1 ml/kg/hour of normal saline solution, starting 12 hours before and continuing 12 hours after iohexol contrast. "B" group received 3 ml/kg of sodium bicarbonate solution (150 mEq/L) one hour prior to procedure and then drip rate was decreased to 1 ml/kg/hour until 6 hours post procedure. Our main outcome measure was change in serum creatinine. Results: The mean creatinine value after the procedure was 1.26 mg/dL in the saline group and 1.22 mg/dL in the bicarbonate group (mean difference: 0.036; CI 95%: -0.16 to 0.23, p = 0.865). The diagnosis of contrast-induced nephropathy, defined by increase in serum creatinine on 25% or more within 2 days after administration of radiographic contrast, was done in twelve patients (12%) in the bicarbonate group and eighth patients (7.

  8. Stress corrosion cracking tests on electron beam welded carbon steel specimens in carbonate-bicarbonate solution

    International Nuclear Information System (INIS)

    Stress corrosion cracking tests have been performed on tapered carbon steel test pieces containing electron beam welds with a view to defining susceptibility to such cracking in a carbonate-bicarbonate solution at 90 C and an appropriate electrode potential. The tests involved applying cyclic loads to the specimens and it is shown that the threshold stress for cracking reduces linearly with increase in the magnitude of the cyclic load component. Extrapolation of these trends to zero fluctuating stress indicates static load threshold stresses in the vicinity of the yield stress (i.e. about 300 N/mm2 for parent plate without a weld, 400 N/mm2 for specimens with welds on one side only and 600 N/mm2 for specimens having welds penetrating through the thickness of the specimen). The averages of the maximum crack velocities observed were least for parent plate material and greatest for weld metal, the former being essentially intergranular in morphology and the latter mostly transgranular, with heat affected zone material being intermediate between these extremes. (author)

  9. Nutrient intake, acid base status and weight gain in water buffalo calves fed different dietary levels of sodium bicarbonate

    Scientific Electronic Library Online (English)

    M, Sarwar; M.A, Shahzad; M, Nisa; S, Amjad.

    Full Text Available The impact of different dietary levels of sodium bicarbonate (NaHCO3) on nutrient intake, acid-base status, nitrogen balance and weight gain was examined in growing male buffalo (Bubalus bubalis) calves exposed to hot summer conditions. In a complete randomized block design 60 animals of similar age [...] and weight were divided into five treatment groups of 12 per group. Five isonitrogenous and isoenergetic diets were formulated and randomly allocated to a treatment group. The control diet (0SB) contained no NaHCO3, while diets 4SB, 8SB, 12SB and 16SB contained 0.4, 0.8, 1.2 and 1.6% NaHCO3, respectively. An increase in nutrient intake was recorded with increasing dietary NaHCO3 level while the reverse was true for nutrient digestibility. Calves fed the 12SB and 16SB diets had higher nitrogen retentions than those fed the 0SB and 4SB diets. Significant increases in blood pH, serum HCO3 and urine pH were recorded with increasing NaHCO3 levels, with the highest in calves receiving the 16SB diet. Calves fed the 14SB and 16SB diets gained more weight than those fed the 0SB and 4SB diets. These results indicate that the best nutrient intake, acid-base status, nitrogen retention and weight gain occurred in the calves receiving the diet containing 1.2% NaHCO3.

  10. Evaluation of BSK-H Complete Medium Supplemented with Rabbit Serum and Sodium Bicarbonate for the Growth of Borrelia anserina

    Directory of Open Access Journals (Sweden)

    Bilal Aslam, Iftikhar Hussain*, Muhammad Shahid Mahmood and Ahrar Khan1

    2013-04-01

    Full Text Available The present study was conducted to compare the effect of 3 formulations Barbour-Stoenner-Kelly (BSK medium on the growth of Borrelia (B. anserina, the causative agent of avian borreliosis. Three different formulations of BSK medium (BSK-H, BSK-II and BSK-H complete medium were prepared. For the isolation of B. anserina, Argas ticks were inoculated in all the three (BSK-H, BSK-II and BSK-H complete formulations of BSK medium. All the samples were also observed for the impact of BSK medium on the growth (Generation time, Growth per hour, Specific growth rate of B. anserina. Phase contrast microscopy was performed for the observation of viable B. anserina cells, and additional confirmation of all the isolates was done by performing indirect immunofluorescence assay and PCR. BSK-H complete medium supplemented with 6% rabbit serum and sodium bicarbonate was found best when compared to two other formulations of BSK medium with respect to the isolation, generation time and growth rate of Borrelia spirochetes.

  11. Vanadium oxide dissolution in sodium carbonate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Cherkashin, V.I.; Doroshenko, V.P.; Goncharov, I.A.; Denisova, G.V. (Zaporozhskij Industrial' nyj Inst. (Ukrainian SSR))

    1983-01-01

    Kinetics of dissolution process of powdered vanadium (5) oxide in sodium carbonate is studied. Activation energy of chemical dissolution of V/sub 2/O/sub 5/ at sodium carbonate concentration up to 0.6 mol/dm/sup 3/ constitutes 35.2 kJ/mol. With sodium carbonate concentration increase the dissolution activation energy decreases to 32.5 kJ/mol. Absolute values of activation energy of the dissolution process, dependence of the reaction order on the temperature in the range of low sodium carbonate concentration, testify to the presence of kinetic difficulties in the process studied. Thus, the process of V/sub 2/O/sub 5/ dissolution in sodium carbonate solutions proceeds in the mixed region and obeys regularities of the mixed kinetics.

  12. Conjugated linoleic acids content in M.longissimus dorsi of Hanwoo steers fed a concentrate supplemented with soybean oil, sodium bicarbonate-based monensin, fish oil.

    Science.gov (United States)

    Song, M K; Jin, G L; Ji, B J; Chang, S S; Jeong, J; Smith, S B; Choi, S H

    2010-06-01

    We hypothesized that increasing ruminal pH would lead to enrichment of adipose tissue with conjugated linoleic acid (CLA). Twenty-four Korean native (Hanwoo) steers were used to investigate the additive effects of monensin (30ppm, SO-BM) and/or fish oil (0.7%, SO-BMF) in the diets along with soybean oil (7%) and sodium bicarbonate (0.5%, SO-B) on cis-9, trans-11 and trans-10, cis-12 CLAs in adipose tissue. The steers were assigned to randomly four groups of six animals each based on body weight. The control group (CON) was fed a commercial concentrate for the late fattening stage. Supplementation of oil and sodium bicarbonate reduced feed intake and daily gain, and fish oil further decreased feed intake (Pfatty acids were higher (P=0.03) in steers fed SO than in CON steers. PMID:20374887

  13. Americium(3) oxidation in bicarbonate-carbonate medium by sodium perxenate

    International Nuclear Information System (INIS)

    The action of Na4XeO6 on Am(3) in KHCO3, KHCO3+K2CO3 and K2CO3 solution is investigated by the spectrophotometric method. It is ascertained that in 1.5 mol/l solutions (in terms of HCO3-+CO32-) at the concentrations of perxenate comparable with Am concentrates, the latter fastly moves in Am(4)+Am(5)+Am(6) mixture. The mechanism of Am(3) oxidation with perxanate is proposed; it includes reactions of Am(3 with Xe(3) and, probably, with Xe(6). 9 refs

  14. The effects of acute and chronic sodium bicarbonate supplementation on high-intensity intermittent performance, recovery and subsequent performance in rugby union players

    OpenAIRE

    Fitzpatrick, Paula

    2012-01-01

    Exogenous ingestion of alkalising agents, such as sodium bicarbonate (SB), has been shown to enhance muscle buffering capacity, thereby delaying the metabolic acidosis associated with high-intensity exercise and potentially improving performance. Aim: The aim of this research was to examine the effects of acute and chronic SB supplementation and a placebo (PLA) on high-intensity intermittent performance, recovery and subsequent performance in trained rugby union players. Methods: This aim was...

  15. Oral Prostaglandin E1 in Combination with Sodium Bicarbonate and Normal Saline in the Prevention of Contrast-Induced Nephropathy: A Pilot Study

    OpenAIRE

    Franz, Randall W.; Hinze, Scott S.; Knapp, Eric D.; Jenkins, James J.

    2011-01-01

    The purpose of this study was to evaluate the use of prostaglandin E1 (PGE1) as a renal protective medication for patients exposed to contrast agents, as well as to demonstrate the safety, efficacy, and low side-effect profile of PGE1. A prospective, randomized, double-blind study was designed to compare combination of intravenous sodium bicarbonate, normal saline, and oral PGE1 200 ?g versus the combination and placebo for renal protection from contrast agents. All patients receiving nonioni...

  16. Effects of sodium bicarbonate ingestion on performance and perceptual responses in a laboratory-simulated BMX cycling qualification series.

    Science.gov (United States)

    Zabala, Mikel; Requena, Bernardo; Sánchez-Muñoz, Cristóbal; González-Badillo, Juan José; García, Inmaculada; Oöpik, Vahur; Pääsuke, Mati

    2008-09-01

    The objective of this study was to examine the effect of sodium bicarbonate (NaHCO3-) ingestion on performance and perceptual responses in a laboratory-simulated bicycle motocross (BMX) qualification series. Nine elite BMX riders volunteered to participate in this study. After familiarization, subjects undertook two trials involving repeated sprints (3 x Wingate tests [WTs] separated by 30 minutes of recovery; WT1, WT2, WT3). Ninety minutes before each trial, subjects ingested either NaHCO3- or placebo in a counterbalanced, randomly assigned, double-blind manner. Each trial was separated by 4 days. Performance variables of peak power, mean power, time to peak power, and fatigue index were calculated for each sprint. Ratings of perceived exertion were obtained after each sprint, and ratings of perceived readiness were obtained before each sprint. No significant differences were observed in performance variables between successive sprints or between trials. For the NaHCO3- trial, peak blood lactate during recovery was greater after WT2 (p < 0.05) and tended to be greater after WT3 (p = 0.07), and ratings of perceived exertion were not influenced. However, improved ratings of perceived readiness were observed before WT2 and WT3 (p < 0.05). In conclusion, NaHCO3- ingestion had no effect on performance and RPE during a series of three WT simulating a BMX qualification series, possibly because of the short duration of each effort and the long recovery time used between the three WTs. On the contrary, NaHCO3- ingestion improved perceived readiness before each WT. PMID:18714219

  17. Dietary supplementation with sodium bicarbonate improves calcium absorption and eggshell quality of laying hens during peak production.

    Science.gov (United States)

    Jiang, M J; Zhao, J P; Jiao, H C; Wang, X J; Zhang, Q; Lin, H

    2015-12-01

    The advantage of supplemental sodium bicarbonate (NaHCO3) on eggshell quality in laying hens changes with age. Besides increasing calcium (Ca) secretion in the eggshell gland, it may improve Ca absorption in the intestine or kidney. Hy-Line Brown layers (n = 384), 25 weeks of age, were allocated to two treatment groups in two experiments, each of which included 4 replicates of 24 hens. Hens were fed a basal diet (control) or the basal diet containing 3 g NaHCO3 g/kg for 50 or 20 weeks in Experiment 1 or 2, respectively. A 24-h continuous lighting regimen was used to allow hens to consume the dietary supplements during the period of active eggshell formation. In Experiment 1, particularly from 25 to 50 weeks of age, and in Experiment 2, NaHCO3 supplementation favoured hen-d egg production at the expense of lower egg weight. The increased eggshell thickness should have nothing to do with the additional eggshell formation, because of the unchanged egg mass and daily eggshell calcification. At 35 weeks of age in both experiments, NaHCO3 supplementation increased duodenal expression of calbindin-d28k (CaBP-D28k) protein, contributing to higher Ca retention and balance. From 50 to 75 weeks of age in Experiment 1, the hens had little response to NaHCO3 supplementation and showed a negative trend on eggshell thickness and strength. It is concluded that dietary supplementation with 3 g NaHCO3 g/kg improves Ca absorption and eggshell quality of laying hens during the peak but not late production period, with the introduction of continuous lighting. PMID:26569471

  18. The potential effects of sodium bicarbonate, a major constituent from coalbed natural gas production, on aquatic life

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.

    2012-01-01

    The production water from coalbed natural gas (CBNG) extraction contains many constituents. The U.S. Environmental Protection Agency has established aquatic life criteria for some of these constituents, and it is therefore possible to evaluate their risk to aquatic life. However, of the major ions associated with produced waters, chloride is the only one with an established aquatic life criterion (U.S. Environmental Protection Agency, 1988). The focus of this research was NaHCO3, a compound that is a major constituent of coalbed natural gas produced waters in the Tongue and Powder River Basins. This project included laboratory experiments, field in situ experiments, a field mixing zone study, and a fishery presence/absence assessment. Though this investigation focuses on the Tongue and Powder River Basins, the information is applicable to other watersheds where sodium bicarbonate is a principle component of product water either from CBNG or from traditional or unconventional oil and gas development. These data can also be used to separate effects of saline discharges from those potentially posed by other constituents. Finally, this research effort and the additional collaboration with USGS Water Resources and Mapping, Bureau of Land Management, US Environmental Protection Agency, State of Montana, State of Wyoming, Montana State University, University of Wyoming, and others as part of a Powder River Aquatic Task Group, can be used as a model for successful approaches to studying landscapes with energy development. The laboratory acute toxicity experiments were completed with a suite of organisms, including 7 species of fish, 5 species of invertebrates, and 1 amphibian species. Experiments performed on these multiple species resulted in LC50s that ranged from 1,120 to greater than (>) 8,000 milligrams sodium bicarbonate per liter (mg NaHCO3/L) (also defined as 769 to >8,000 milligrams bicarbonate per liter (mg HCO3-/L) or total alkalinity expressed as 608 to >4,181 milligrams calcium carbonate per liter (mg CaCO3/L)) that varied across species and lifestage within a species. The age at which fish were exposed to NaHCO3 significantly affected the severity of toxic responses for some organisms. The chronic toxicity of NaHCO3 was defined in experiments that lasted from 7—60 days post-hatch. For these experiments, sublethal effects such as growth and reproduction, in addition to significant reductions in survival were included in the final determination of effects. Chronic toxicity was observed at concentrations that ranged from 450 to 800mg NaHCO3/L (also defined as 430 to 657 mg HCO3-/L or total alkalinity expressed as 354 to 539 mg CaCO3/L) and the specific concentration depended on the sensitivity of the four species of invertebrates and fish exposed. Sublethal investigations during chronic studies revealed percent decrease in the activity of sodium-potassium adenosine triphosphatase (Na/K ATPase, an enzyme involved in ionoregulation) and the age of the fish at the onset of the decrease may affect the ability of fathead minnow to survive exposures to NaHCO3. A database of toxicity evaluations of NaHCO3 on aquatic life has been constructed. Using these data, sample acute and chronic criteria of 459 and 381 mg NaHCO3/L, respectively, can be calculated for the protection of aquatic life. The final derivation and implementation of such criteria is, of course, left to the discretion of the concerned management agencies. A combination of in situ experiments, static-renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory, demonstrated that untreated coalbed natural gas (CBNG) product water from the Tongue and Powder River Basins reduces survival of fathead minnow and pallid sturgeon. More precisely, the survival of early-lifestage fathead minnow, especially those less than 6-days post hatch (dph), likely is reduced significantly in the field when concentrations of NaHCO3 rise above 1,500 mg/L. However, age was not a factor for pallid

  19. Effect of ambient temperature and sodium bicarbonate supplementation on water and electrolyte balances in dry and lactating Holstein cows.

    Science.gov (United States)

    Khelil-Arfa, H; Faverdin, P; Boudon, A

    2014-04-01

    The aim of this study was to quantify the effect of the interaction between 2 constant ambient temperatures [thermoneutrality (TN; 15°C) and high temperature (HT; 28°C)] and 2 levels of Na bicarbonate supplementation [calculated to provide diet Na contents of 0.20%DM (Na-) and 0.50%DM (Na+)] on water partitioning in dairy cows. Treatments were compared on 4 dry and 4mid-lactation Holstein cows according to 2 Latin squares (1 for each physiological stage) over the course of 4 periods of 15d. Diets consisted of a total mixed ration based on maize silage. Dry cows were restricted to their protein and energy requirements, whereas lactating cows were fed ad libitum. The daily average temperature-humidity index was 59.4 for TN and 73.2 for HT. Lactating and dry cows had higher vaginal temperatures at HT than at TN, but the increase was more pronounced in lactating cows (+1.05 vs. +0.12°C for vaginal temperature, respectively). Dry matter intake (DMI) of lactating cows decreased by 2.3kg/d at HT. Free water intake (FWI) and estimated volume of water lost to evaporation increased at HT in both lactating and dry cows; no interactions were observed between temperature and physiological stage. When expressed as a proportion of DMI, the increase in evaporation that occurred with increasing temperature was completely compensated for by an increase in FWI for both physiological stages. The urinary water excretion increased slightly at HT in lactating cows but not in dry cows, which may be related to the low chloride content of the offered diet. High Na supplementation increased DMI slightly in lactating cows, but milk yield was not affected. Sodium supplementation did not limit the decrease in DMI observed in lactating cows at HT; this observation is likely due to the high diet electrolyte balance of the offered diets. Sodium supplementation increased FWI in lactating cows and urinary flow in both physiological states. The interaction between ambient temperature and Na supplementation did not affect either water intake or water evaporation. This study demonstrates that the development of predictive models for water intake that include environmental variables could be based on mechanistic models of evaporation. PMID:24485695

  20. Intraocular Irrigating Solutions. A Clinical Study of BSS Plus ® and Dextrose Bicarbonate Fortified BSS ® as an Infusate during Pars Plana Vitrectomy.

    Directory of Open Access Journals (Sweden)

    Samuel Michael

    2003-01-01

    Full Text Available Purpose: To compare the effect of Balanced Salt Solution Plus (BSS Plus, Alcon Laboratories, Fort Worth, Texas, USA and fortified regular BSS on the cornea and lens, when used for continuous irrigation in pars plana vitrectomy (PPV surgery. Methods: Prospective, investigator masked, randomised study. Forty patients were randomly assigned to undergo PPV using BSS Plus (n=20 or fortified BSS (n=20 [regular BSS, fortified with 10.5 cc. of dextrose in water (D5W and 13.1cc. of 8.4% sodium bicarbonate]. Intraoperative features of the corneal epithelium, postoperative changes in the corneal endothelial cell denstiy (ECD at 3 months, and clarity of the lens during surgery and postoperatively were evaluated. Results: Intraoperative epithelial changes were similar in both groups with 7 (35% of the cases having the epithelium removed in the BSS Plus group and 8 (40% in the BSS fortified group (P=0.23. The mean differences in ECD (3 months versus preoperative in the operated eyes when adjusted for changes in the control eye showed no difference with the type of BSS (P=0.98. Intraoperative lens changes were more significant (P=0.018 in the BSS fortified group. Postoperative lens status at 3 months was similar for both groups. Though there was a trend towards worse postoperative nuclear sclerosis change in the BSS fortified group, it was not significant (P=0.160. Conclusion: Standard BSS fortified with dextrose and bicarbonate is an efficacious infusion fluid during pars plana vitrectomy. Both solutions showed comparable effects on postoperative corneal endothelial cell density and corneal epithelial changes intraoperatively. BSS fortified has more lenticular changes intraoperatively than BSS Plus although no lens had to be removed in either group. The study implications are important since BSS fortified is significantly less expensive than BSS Plus.

  1. The effect of sodium bicarbonate as an abrasive media on ferrous and non-ferrous metal surfaces

    International Nuclear Information System (INIS)

    The effect of bicarbonate ions on the surface of carbon steel, aluminium and copper has been investigated using corrosion analyzer. The corrosion rate of samples due to corrosion action, under static conditions at room temperature has been obtained from the current response using Faradays law. The degree of bicarbonate ions attack was referred to the corrosion rate of each sample. The significant resistance to corrosion and the outstanding stability of the corrosion resistance shows that the excellent performances of the carbon steel over that of aluminium and copper. From the results obtained show that the bicarbonate ions were not attacked on the surface of carbon steel but slightly attacked on the aluminium and copper surfaces. (Author)

  2. Viscosity and density tables of sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Fair, J.A.; Ozbek, H. (comps.)

    1977-04-01

    A file is presented containing tabulated data extracted from the scientific literature on the density and viscosity of aqueous sodium chloride solutions. Also included is a bibliography of the properties of aqueous sodium chloride solutions. (MHR)

  3. Effects of dietary supplemental sodium bicarbonate on some egg characteristics and blood parameters in Japanese Quail reared under high enviromental temperature

    OpenAIRE

    Okan, Ferda

    1998-01-01

    The aim of this study was to determine the effects of dietary supplemental sodium bicarbonate on egg production, egg weight, shell quality, feed conversion efficiency, blood pH, plasma Na+ values and blood gas in Japanese quail Layers reared under high environmental temperature. In this study, 9 weeks old 60 female Japanese quail Layers were used and divided equally into two groups. The control group was fed with basal diet where the second group was fed with a diet containing 0.2 % NaHCO3. ...

  4. Effects of an Ionophore Coccidiostat (Monensin or Salinomycin, Sodium or Potassium Bicarbonate, or Both, and Bacitracin Methylene Disalicylate in Broiler Chicken Diets

    Directory of Open Access Journals (Sweden)

    Hooge DM

    2000-01-01

    Full Text Available Peterson x Arbor Acres chicks were grown on used litter to 45 or 46 days of age in three pen trials. Coccidial inoculations were given by water at 14 days of age. Sodium bicarbonate (SBC; 0.20% or potassium bicarbonate (PBC; 0.14% was added to broiler chicken diets containing monensin (MON; 110 mg/kg or salinomycin (SAL; 66 mg/kg in Experiment 1. In Experiment 2, using SAL (55 mg/kg, three dietary bicarbonate treatments (SBC, 0.20%; PBC, 0.20%; or SBC + PBC 0.10% each were tested with or without BMD R (55 mg/kg. Diets differing in SAL, BMD R, and SBC levels were evaluated in Experiment 3. Beneficial interaction was found between ionophores and bicarbonates for mortality (lower when SBC or PBC and MON in Experiment 1. For main effects, in Experiment 1 PBC with MON or SAL improved body weight, feed conversion ratio and mortality. SAL improved weight, feed conversion ratio and mortality compared to MON. In Experiment 2, PBC with SAL improved weight, coccidial lesion score, feed conversion ratio and mortality across two levels of BMD R. The PBC and SBC were equally effective in Experiment 1, but PBC was about 0 to 40% as effective as SBC, depending on parameter in Experiment 2. Half levels of SBC plus PBC generally gave intermediate results between control and SBC. SBC with MON or SAL lowered mortalities, coccidial lesion scores, and feed conversion ratios (Experiments 1 and 2, and increased body weight (Experiment 2. In Experiment 3, BMD R in all feeds improved body weight and feed conversion versus in starter feed only, and SBC with SAL and BMD R improved all performance parameters.

  5. Np(V)/Np(IV) in concentrated carbonate/bicarbonate solutions; Np(V)/Np(IV) en solutions carbonate/bicarbonate concentrees

    Energy Technology Data Exchange (ETDEWEB)

    Delmau, L.H.; Vitorge, P.; Capdevila, H.

    1996-01-01

    A 1.5 M Na{sub 2}CO{sub 3} solution of Np(V) is electrolysed to Np(IV) at -2.0 V/SHE. -1g(H{sup +}) is decreased from 10.4 to 7.2 by bubbling CO{sub 2} in these solutions, where Np(IV) spectra can be interpreted with the only lost of one CO{sub 3}{sup 2-} anion from the Np(IV) limiting complex. From these spectral changes, the following parameters are fitted: 20.5 {+-} 2.1, 8.44 {+-} 0.9 and 28.9 {+-} 2.9 l/mol./cm for the Np(CO{sub 3}){sub 5}{sup 6-} molar absorptivity at 823, 990 and 1013 nm respectively, and 54.5 {+-} 5.5, 40.6 {+-} 4.1 and 8.53 {+-} 0.9 for the Np(CO{sub 3}){sub 4}{sup 4-} ones, and log((Np(CO{sub 3}){sub 5}{sup 6-}) / ((Np(CO{sub 3}){sub 4}{sup 4-})(CO{sub 3}{sup 2-}))) = 1.47 {+-} 0.08, 1.63 {+-} 0.05, 1.80 {+-} 0.04, 1.79 {+-} 0.10 and 2.21 {+-} 0.03 at the half point reaction in initially 0.2, 0.3, 0.4, 0.5 and 0.6 M Na{sub 2}CO{sub 3} solutions. These values are extrapolated to 0 ionic strength by using the Specific Interaction Theory (SIT). The redox potential of 0.3, 0.6, 1 and 1.5 M Na{sub 2}CO{sub 3} solutions of Np(V) and Np(IV) mixtures, is stable usually after three hours at T from 5 to 60 deg C, and then for up to three weeks at 21.5 deg C. At 25 deg C, its values are 0.247, 0.234, 0.244 and 0.228 V/SEH in 0.3, 0.6, 1 and 1.5 M Na{sub 2}CO{sub 3} solutions. When the tonic strength is equal to 0: E = 0.52 {+-} 0.1 V/SEH and {Delta}S/F = -1.1 {+-} 0.7 mV. deg C{sup -1}. Assuming this potential is controlled by the NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-} + 2 CO{sub 2} + e{sup -} {r_reversible} Np(CO{sub 3}){sub 5}{sup 6-} equilibrium, the formation constant of the limiting complex is deduced by using published values of the other needed equilibria: log {Beta}{sub 5}{sup d}eg = 38 {+-} 4. Qualitative results on the preparation and on the spectra of Np(IV) are used to explain the apparent contradictions between some published results. (authors). 39 refs., figs., tabs.

  6. Metabolic attributes, yield and stability of milk in Jersey cows fed diets containing sodium citrate and sodium bicarbonate / Atributos metabólicos, produtividade e estabilidade do leite em vacas Jersey alimentadas com dietas com citrato de sódio e bicarbonato de sódio

    Scientific Electronic Library Online (English)

    Marcelo Tempel, Stumpf; Vivian, Fischer; Giovani Jacob, Kolling; Maira Balbinotti, Zanela; Maria Edi Rocha, Ribeiro; Alexandre Süsenbach de, Abreu.

    2013-05-01

    Full Text Available O objetivo deste trabalho foi avaliar a inclusão de citrato de sódio e de bicarbonato de sódio na dieta de vacas lactantes Jersey e seus efeitos sobre os atributos metabólicos, a produtividade e a estabilidade do leite. Foram avaliados o pH urinário, os níveis sanguíneos de glicose e ureia, o peso e [...] o escore de condição corporal, a produção e a estabilidade do leite (teste do álcool) e as propriedades físico?químicas do leite de 17 vacas, alimentadas com dietas com citrato de sódio (100 g por vaca por dia), bicarbonato de sódio (40 g por vaca por dia) ou sem aditivos. As avaliações foram feitas no 28º e 44º dias. O fornecimento de citrato ou de bicarbonato de sódio não influencia os atributos metabólicos, a produtividade, o peso e o escore de condição corporal das vacas, nem a composição ou a estabilidade do leite. Abstract in english The objective of this work was to evaluate the inclusion of sodium citrate and sodium bicarbonate in the diet of lactating Jersey cows, and its effects on the metabolic attributes, productivity and stability of milk. We evaluated urinary pH, levels of glucose and urea in blood, body weight, body con [...] dition score, milk yield, milk stability (ethanol test), and milk physicochemical properties of 17 cows fed diets containing sodium citrate (100 g per cow per day), sodium bicarbonate (40 g per cow per day) or no additives. Assessments were made at the 28th and 44th days. Supply of sodium citrate or bicarbonate has no influence on the metabolic attributes, productivity, body weight, and body condition score of the cows, neither on the composition and stability of milk.

  7. X-ray diffraction studies on merohedrally twinned ?1–62NtNBCe1-A crystals of the sodium/bicarbonate cotransporter

    International Nuclear Information System (INIS)

    A truncated mutant missing the first 62 residues of the N-terminal, cytoplasmic domain of the sodium-bicarbonate NBCe1-A cotransporter crystallizes in space group P31 with pseudo-P3121 symmetry and a hemihedral twin fraction of 33.0%. Twinned fractions and twin-pair statistics over binned resolutions confirm that the calculated twin fraction is associated with hemihedral twinning and not to non-crystallographic symmetry. NBCe1-A membrane-embedded macromolecules that cotransport sodium and bicarbonate ions across the bilayer serve to maintain acid–base homeostasis throughout the body. Defects result in a number of renal and eye disorders, including type-II renal tubular acidosis and cataracts. Here, crystals of a human truncated mutant of the cytoplasmic N-terminal domain of NBCe1 (?1–62NtNBCe1-A) are reported that diffract X-rays to 2.4 Å resolution. The crystal symmetry of ?1–62NtNBCe1-A is of space group P31 with pseudo-P3121 symmetry and it has a hemihedral twin fraction of 33.0%. The crystals may provide insight into the pathogenic processes observed in a subset of patients with truncating and point mutations in the gene encoding NBCe1

  8. Sodium bicarbonate ingestion augments the increase in PGC-1? mRNA expression during recovery from intense interval exercise in human skeletal muscle.

    Science.gov (United States)

    Percival, Michael E; Martin, Brian J; Gillen, Jenna B; Skelly, Lauren E; MacInnis, Martin J; Green, Alex E; Tarnopolsky, Mark A; Gibala, Martin J

    2015-12-01

    We tested the hypothesis that ingestion of sodium bicarbonate (NaHCO3) prior to an acute session of high-intensity interval training (HIIT) would augment signaling cascades and gene expression linked to mitochondrial biogenesis in human skeletal muscle. On two occasions separated by ?1 wk, nine men (mean ± SD: age 22 ± 2 yr, weight 78 ± 13 kg, V?o2 peak 48 ± 8 ml·kg(-1)·min(-1)) performed 10 × 60-s cycling efforts at an intensity eliciting ?90% of maximal heart rate (263 ± 40 W), interspersed with 60 s of recovery. In a double-blind, crossover manner, subjects ingested a total of 0.4 g/kg body weight NaHCO3 before exercise (BICARB) or an equimolar amount of a placebo, sodium chloride (PLAC). Venous blood bicarbonate and pH were elevated at all time points after ingestion (P 0.05). However, the increase in PGC-1? mRNA expression after 3 h of recovery was higher in BICARB vs. PLAC (approximately sevenfold vs. fivefold compared with rest, P < 0.05). We conclude that NaHCO3 before HIIT alters the mRNA expression of this key regulatory protein associated with mitochondrial biogenesis. The elevated PGC-1? mRNA response provides a putative mechanism to explain the enhanced mitochondrial adaptation observed after chronic HIIT supplemented with NaHCO3 in rats. PMID:26384407

  9. Substituição de monensina sódica por bicarbonato de sódio em dietas de novilhas confinadas / Evaluation of the replacement of Monensin with Sodium Bicarbonate in diets for confined bovines

    Scientific Electronic Library Online (English)

    A.P., Oliveira; R.A., Reis; L.M.A., Bertipaglia; G.M.P., Melo; T.T., Berchielli; J.A., Oliveira; D.R., Casagrande; M.A.A., Balsalobre.

    2013-08-01

    Full Text Available Avaliaram-se os efeitos da substituição da monensina sódica pelo bicarbonato de sódio em dietas de novilhas em confinamento em relação ao desempenho animal, à conversão alimentar e ao parâmetro de fermentação ruminal. Foram utilizadas 56 novilhas mestiças, confinadas por 112 dias, submetidas a dieta [...] s com duas porcentagens de concentrado, 50% e 80% da matéria seca, com adição de monensina sódica ou bicarbonato de sódio, em fatorial 2x2. O volumoso utilizado para compor as dietas testadas foi composto de silagem de milho e cana-de-açúcar na proporção de 60:40, respectivamente. O nitrogênio amoniacal foi maior nos animais alimentos com dietas com alto grão. A monensina, na dieta 80:20, proporcionou maiores valores de nitrogênio amoniacal, uma e nove horas após o consumo da ração. O uso de bicarbonato promoveu os maiores valores de pH ruminal na dieta com 50% de concentrado, de seis a 18 horas após o consumo. Não houve efeito do aditivo sobre o desempenho animal. A alta inclusão de grãos na dieta propiciou aumento do desempenho animal e da eficiência alimentar. Conclui-se que o uso de bicarbonato de sódio em dietas para terminação de animais em confinamento é uma opção viável em substituição à monensina sódica para a manipulação da fermentação ruminal. Abstract in english The effects of replacing monensin with sodium bicarbonate in diets for confined heifers on weight gain (WG), dry matter intake (DMI), feed:gain ratio (FGR) and rumen fermentation parameters were evaluated. Fifity six heifers were utilized (Santa Gertrudis x Braunvieh). Diets were formulated with two [...] levels of concentrate (50% and 80% concentrate) with sodium monensin or sodium bicarbonate. The DMI was higest in heifers with an intake of 80% concentrate. There was not difference when the same concentrate levels were evaluated in relation to the DMI. The heifers at 80% concentrate showed highest WG. There was no significant difference in relation to WG between monensin and bicarbonate treatments and levels concentrate proportions. There were significant effects regarding FGR between treatments. The heifers on 80% concentrate showed lowest FGR. In the evaluation of N-NH3, the highest values were observed, on the whole, at 80:20 diets in relation to 50:50 diets. In the additive use, the monensin on 80:20 diets promoted the highest values of N-NH3 at 1 for 9 hours after feed intake. In the values of ruminal pH, the bicarbonate increased the values on 50:50 at 6 for18 hours after feed intake, in relation to the 80:20 diet. In this case, it was concluded that the use of sodium bicarbonate in diets for confined finishing heifers is a viable option for the replacement of monensin sodium.

  10. Bicarbonate Test

    Science.gov (United States)

    ... effectiveness of treatment for known imbalances. When an acid-base imbalance is identified, bicarbonate (as part of the electrolyte panel) and blood gases may be ordered to evaluate the severity of ...

  11. Preparation of excipient-free recombinant human tissue-type plasminogen activator by lyophilization from ammonium bicarbonate solution: an investigation of the two-stage sublimation phenomenon.

    Science.gov (United States)

    Overcashier, D E; Brooks, D A; Costantino, H R; Hsu, C C

    1997-04-01

    Dry, excipient-free recombinant human tissue-type plasminogen activator (tPA) powder was prepared by lyophilization from ammonium bicarbonate solution. Ammonium bicarbonate sublimes into ammonia, water, and carbon dioxide upon lyophilization, without causing measurable harm to the protein. There were approximately 4 mol of residual ammonium ion per mole of lyophilized tPA. Under certain lyophilization conditions, a large pressure increase in the lyophilizer chamber occurred, presenting a pressure control problem. Microscopy and sublimation rate measurements on the frozen matrix revealed that ice sublimation occurred first, followed by the sublimation of ammonium bicarbonate. Analysis of the sectioned frozen matrix indicated that the bicarbonate salt was evenly distributed throughout the vial, suggesting that the delay of ammonium bicarbonate sublimation was not due to hindrance by ice. In the two-stage process, ice sublimation proceeded according to zero-order kinetics, whereas ammonium bicarbonate sublimation followed a grain-burning (2/ 3-order) model and was governed by a higher activation enthalpy. In most cases, the sublimation rate of ammonium bicarbonate in the presence of tPA was lower than that in the absence of the protein. Sublimation activation enthalpy for ammonium bicarbonate in the presence of tPA was 26.1 +/- 3.8 kcal/mol, which was approximately 10 kcal/mol greater than that for the tPA-free system. Consistent with a prediction from our kinetic modeling, a 6-h extension of primary drying enabled us to conduct lyophilization while maintaining pressure control. PMID:9109048

  12. Acute toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters, to 13 aquatic species as defined in the laboratory

    Science.gov (United States)

    Harper, David D.; Farag, Aida M.; Skaar, Don

    2014-01-01

    Water produced during coal bed natural gas (CBNG) extraction in the Powder River Structural Basin of Wyoming and Montana (USA) may contain concentrations of sodium bicarbonate (NaHCO3) of more than 3000?mg/L. The authors evaluated the acute toxicity of NaHCO3, also expressed as bicarbonate (HCO3?), to 13 aquatic organisms. Of the 13 species tested, 7 had a median lethal concentration (LC50) less than 2000?mg/L NaHCO3, or 1300?mg/L HCO3?. The most sensitive species were Ceriodaphnia dubia, freshwater mussels (Lampsilis siliquoidea), pallid sturgeon (Scaphirhynchus albus), and shovelnose sturgeon (Scaphirhynchus platorynchus). The respective LC50s were 989?mg/L, 1120?mg/L, 1249?mg/L, and 1430?mg/L NaHCO3, or 699?mg/L, 844?mg/L, 831?mg/L, and 1038?mg/L HCO3?. Age affected the sensitivity of fathead minnows, even within life stage. Two days posthatch, fathead minnows were more sensitive to NaHCO3 and HCO3? compared with 4-d-old fish, even though fish up to 14 d old are commonly used for toxicity evaluations. The authors recommend that ion toxicity exposures be conducted with organisms less than 24?h posthatch to ensure that experiments document the most sensitive stage of development. The results of the present study, along with historical and current research regarding the toxicity of bicarbonate, may be useful to establish regulatory standards for HCO3?.

  13. The variation of calcium, magnesium, sodium, potassium and bicarbonate concentration, pH and conductivity in groundwater of Karachi region

    International Nuclear Information System (INIS)

    Groundwater in Karachi is influenced mainly by the evaporation / crystallization process as expressed by the Na/(Na+Ca) weight concentration ratio. The high coefficient of determined between conductivity and total dissolved ions concentration in meq/sup -1/ revealed that major ions affect the conductivity of groundwater. It was also found that groundwater quality with respect to cations is not significantly influenced by geology, particularly in the Urban are of the city, where the 90% of the population resides. The relationship between conductivity and bicarbonate concentration shows that supersaturation of groundwater with carbon dioxide is responsible for general depression of pH. (author)

  14. Effect of enteric coated sodium bicarbonate, enzymes and bile combination on the absorption of fat in chronic pancreatitis

    Directory of Open Access Journals (Sweden)

    . Vukovic M., Jojic N.

    2007-03-01

    Full Text Available The effects of (A H2-receptor antagonist (ranitidine and enzyme preparation with bile constituents (Digestal forte, (B Digestal forte and NaHCO3, (C NaHCO3 alone, or (D Digestal forte alone, on the increase of lipolysis, were studied in a double-blind, randomized, prospective, controlled cross-over study in 10 patients with chronic pancreatitis (CP and steatorrhea. All preparations were enteric-coated tablets except ranitidine. The 14C triolein breath test was used to monitor the lipolytic effect of the regimens, the parameter for the efficacy assessment being cumulative recover (CR of 14CO2 after 6 hours. Before the treatment patients underwent the same test procedure. The regimen B produced significantly higher increase in CR, as compared to other regimens (p<0.01. A, B and D regimens induced a significant increase in CR compared to baseline CR (p<0.01, while regimen C had no effect (p>0.05. No differences were observed between the regimes A and D (p>0.05. The results showed that exogenous lipolytic action of Digestal forte remained unaffected by ranitidine (p>0.05. This study suggests that the adding of bicarbonate with Digestal forte may play an important role in the regulation of lypolysis in these patients. Key words: Chronic pancreatitis, enzyme substitution, bicarbonate, ranitidine

  15. Evaluation of the efficacy of oral rehydration solutions using human whole gut perfusion.

    OpenAIRE

    Rolston, D D; Zinzuvadia, S N; Mathan, V I

    1990-01-01

    Whole gut perfusion in humans was used to compare the effect on intestinal water and electrolyte transport of the World Health Organisation oral rehydration solution (solution II, composition in mmol/l: glucose 111, sodium 90, bicarbonate 30, potassium 20; 308 mOsm/kg); a hypertonic commercial oral rehydration solution (solution III, glucose 188, sodium 50, bicarbonate 20, potassium 20 mmol/l; 335 mOsm/kg); and three experimental bicarbonate free, hypotonic oral rehydration solutions: solutio...

  16. Design requirements for uranium ion exchange from ammonium bicarbonate solutions in a fluidized system

    International Nuclear Information System (INIS)

    A fluidized countercurrent ion-exchange system was developed, operated, and evaluated. The system consisted of integrated multiple-compartment absorption and elution columns in which the solution flows were continuous except for short periods when resin increments were withdrawn. The exchange of uranyl carbonate between a simulated in situ uranium leach liquor and a strong-base ion-exchange resin together with the subsequent elution with an ammonium chloride solution was studied. The effects of the number of sections, section height, amount of resin withdrawal, solution flow rate, and column diameter were investigated. The kinetic and equilibrium relationships for the absorption and elution steps were also examined. The experimental data indicate a strong interdependence between variables. Solution retention time appears to be a major limiting variable in the absorption process, while resin residence time is the determining factor in the elution process. The column was efficient over a range of conditions, but close control was needed for optimum operation. 30 figures

  17. Process of attack of uraniferous ores by a solution of potassium carbonate and bicarbonate

    International Nuclear Information System (INIS)

    Oxidizing attack process of uraniferous ores by an aqueous solution of potassium carbonate and dicarbonate in which is introduced a gas containing oxygen under pressure. This process allowing a high solubilization of uranium in a soluble salt form

  18. Stability of Ceftiofur Sodium and Cefquinome Sulphate in Intravenous Solutions

    OpenAIRE

    Agnieszka Do?ha?; Anna Jeli?ska; Marcelina B?benek

    2014-01-01

    Stability of ceftiofur sodium and cefquinome sulphate in intravenous solutions was studied. Chromatographic separation and quantitative determination were performed by using a high-performance liquid chromatography with UV-DAD detection. During the stability study, poly(vinylchloride) minibags were filled with a solution containing 5?mg of ceftiofur sodium or cefquinome sulphate and diluted to 0.2?mg/mL with suitable intravenous solution depending on the test conditions. The solutions for the...

  19. Np(V)/Np(IV) in concentrated carbonate/bicarbonate solutions

    International Nuclear Information System (INIS)

    A 1.5 M Na2CO3 solution of Np(V) is electrolysed to Np(IV) at -2.0 V/SHE. -1g(H+) is decreased from 10.4 to 7.2 by bubbling CO2 in these solutions, where Np(IV) spectra can be interpreted with the only lost of one CO32- anion from the Np(IV) limiting complex. From these spectral changes, the following parameters are fitted: 20.5 ± 2.1, 8.44 ± 0.9 and 28.9 ± 2.9 l/mol./cm for the Np(CO3)56- molar absorptivity at 823, 990 and 1013 nm respectively, and 54.5 ± 5.5, 40.6 ± 4.1 and 8.53 ± 0.9 for the Np(CO3)44- ones, and log((Np(CO3)56-) / ((Np(CO3)44-)(CO32-))) = 1.47 ± 0.08, 1.63 ± 0.05, 1.80 ± 0.04, 1.79 ± 0.10 and 2.21 ± 0.03 at the half point reaction in initially 0.2, 0.3, 0.4, 0.5 and 0.6 M Na2CO3 solutions. These values are extrapolated to 0 ionic strength by using the Specific Interaction Theory (SIT). The redox potential of 0.3, 0.6, 1 and 1.5 M Na2CO3 solutions of Np(V) and Np(IV) mixtures, is stable usually after three hours at T from 5 to 60 deg C, and then for up to three weeks at 21.5 deg C. At 25 deg C, its values are 0.247, 0.234, 0.244 and 0.228 V/SEH in 0.3, 0.6, 1 and 1.5 M Na2CO3 solutions. When the tonic strength is equal to 0: E = 0.52 ± 0.1 V/SEH and ?S/F = -1.1 ± 0.7 mV. deg C-1. Assuming this potential is controlled by the NpO2(CO3)35- + 2 CO2 + e- ? Np(CO3)56- equilibrium, the formation constant of the limiting complex is deduced by using published values of the other needed equilibria: log ?5deg = 38 ± 4. Qualitative results on the preparation and on the spectra of Np(IV) are used to explain the apparent contradictions between some published results. (authors). 39 refs., figs., tabs

  20. Electron transfer across anodic films formed on tin in carbonate-bicarbonate buffer solution

    International Nuclear Information System (INIS)

    Impedance and steady-state data were recorded in order to study the kinetics of electron transfer between passive tin electrodes and an electrolytic solution containing the K3Fe(CN)6-K4Fe(CN)6 redox couple. Film thickness plays a key role in determining the type of electronic conduction of these oxide covered electrodes. Electron exchange with the oxide takes place with participation of the conduction band in the semiconducting film. A mechanism involving direct electron tunneling through the space charge barrier is the most suitable to interpret the experimental evidence

  1. Solution and mechanochemical syntheses, and spectroscopic and structural studies in the silver(I) (bi-)carbonate: triphenylphosphine system.

    Science.gov (United States)

    Bowmaker, Graham A; Effendy; Hanna, John V; Healy, Peter C; King, Scott P; Pettinari, Claudio; Skelton, Brian W; White, Allan H

    2011-07-21

    Syntheses of a number of adducts of silver(I) (bi-)carbonate with triphenylphosphine, both mechanochemically, and from solution, are described, together with their infra-red spectra, (31)P CP MAS NMR and crystal structures. Ag(HCO(3)):PPh(3) (1:4) has been isolated in the ionic form [Ag(PPh(3))(4)](HCO(3))·2EtOH·3H(2)O. Ag(2)CO(3):PPh(3) (1:4) forms a binuclear neutral molecule [(Ph(3)P)(2)Ag(O,μ-O'·CO)Ag(PPh(3))(2)](·2H(2)O), while Ag(HCO(3)):PPh(3) (1:2) has been isolated in both mononuclear and binuclear forms: [(Ph(3)P)(2)Ag(O(2)COH)] and [(Ph(3)P)(2)Ag(μ-O·CO·OH)(2)Ag(PPh(3))(2)] (both unsolvated). A more convenient method for the preparation of the previously reported copper(I) complex [(Ph(3)P)(2)Cu(HCO(3))] is also reported. PMID:21660345

  2. The effect of buffering dairy cow diets with limestone, calcareous marine algae, or sodium bicarbonate on ruminal pH profiles, production responses, and rumen fermentation.

    Science.gov (United States)

    Cruywagen, C W; Taylor, S; Beya, M M; Calitz, T

    2015-08-01

    Six ruminally cannulated Holstein cows were used to evaluate the effect of 2 dietary buffers on rumen pH, milk production, milk composition, and rumen fermentation parameters. A high concentrate total mixed ration [35.2% forage dry matter (DM)], formulated to be potentially acidotic, was used to construct 3 dietary treatments in which calcareous marine algae (calcified remains of the seaweed Lithothamnium calcareum) was compared with limestone (control) and sodium bicarbonate plus limestone. One basal diet was formulated and the treatment diets contained either 0.4% of dietary DM as Acid Buf, a calcified marine algae product (AB treatment), or 0.8% of dietary DM as sodium bicarbonate and 0.37% as limestone (BC treatment), or 0.35% of dietary DM as limestone [control (CON) treatment]. Cows were randomly allocated to treatments according to a double 3×3 Latin square design, with 3 treatments and 3 periods. The total experimental period was 66 d during which each cow received each treatment for a period of 15 d before the data collection period of 7 d. Rumen fluid was collected to determine volatile fatty acids, lactic acid, and ammonia concentrations. Rumen pH was monitored every 10min for 2 consecutive days using a portable data logging system fitted with in-dwelling electrodes. Milk samples were analyzed for solid and mineral contents. The effect of treatment on acidity was clearly visible, especially from the period from midday to midnight when rumen pH dropped below 5.5 for a longer period of time (13 h) in the CON treatment than in the BC (8.7 h) and AB (4 h) treatments. Daily milk, 4% fat-corrected milk, and energy-corrected milk yields differed among treatments, with AB being the highest, followed by BC and CON. Both buffers increased milk fat content. Treatment had no effect on milk protein content, but protein yield was increased in the AB treatment. Total rumen volatile fatty acids and acetate concentrations were higher and propionate was lower in the AB treatment than in CON. The molar proportion of acetate was higher in AB than in CON, but that of propionate was lower in both buffer treatments than in CON. The acetate:propionate ratio was increased in the AB and BC treatments compared with CON. Lactic acid concentration was higher in the CON treatment than in the buffer treatments. Treatment had no effect on rumen ammonia concentrations. Results indicated that buffer inclusion in high concentrate diets for lactating dairy cows had a positive effect on milk production and milk composition. Calcareous marine algae, at a level of 90 g/cow per day, had a greater effect on rumen pH, milk production and milk composition, and efficiency of feed conversion into milk than sodium bicarbonate at a level of 180 g/cow per day. PMID:26026755

  3. Pre-harvest treatments with fungicides and post-harvest dips in sodium bicarbonate to control postharvest decay in stone fruit.

    Science.gov (United States)

    D'Aquino, S; Barberis, A; Satta, D; De Pau, L; Schirra, M

    2012-01-01

    The objective of this study was to evaluate the effectiveness of different commercial formulations of fungicides containing one or more active ingredients in controlling postharvest decay of Thyrinthos and Boccuccia apricots, Red top peaches and Caldesi nectarines. Field treatments consisted of two sprays with cupric compounds, at the end of leaf fall and before bud swelling, one with sulfur compound, at fruit about half final size stage, and one with one of the following commercial formulations at the label suggested rates, one week before harvest: Teldor (fenexamid 50%; Bayer Crop Protection), Folicur (Tebuconazole 4.35%; Bayer Crop Protection), Signum (boscalid 26.7%, pyraclostrobin 6.7%; Basf Crop Protection), Score (difenoconazole 23.23%, Syngenta Crop Protection) and Switch (cyprodinil 37.5%, fludioxonil 25%, Syngenta Crop Protection). After harvest the fruit were stored for 1 week at 6 degrees C and 90% RH followed by 1 week at 20 degrees C and 60% RH to simulate retail conditions, or placed directly at 20 degrees C. All formulations significantly reduced decay in all cultivars. Switch, Signum and Folicur were the most active, while Score was slightly less effective. Teldor activity was low, especially in Thyrintos apricots, where the percentage of rotten fruit was slightly lower than in control fruit. Brown rot was the most representative disease, but in apricots a high percentage of fruit was affected by blue mold and grey mold. Rhizopus rot generally developed as a secondary disease on fruit previously affected by other pathogens and was more frequent in control and Teldor treated fruit. Preharvest sprays with Signum 3 days before harvest reduced postharvest decay after 1 week storage at 20 degrees C in Glo haven peaches and Venus nectarine harvested at advanced stage of maturity. Combining pre-harvest sprays with Signum and a 2-min postharvest dip in 2% sodium bicarbonate at 20 degrees C further reduced decay. In Sothern regions of Italy, the use of synthetic fungicides only immediately before harvest in years when the weather conditions are not favorable to brown rot and other pathogens inducing postharvest decay, combined with a postharvest treatment with sodium bicarbonate could be a feasible integrated approach to reduce the risk of selection of resistant strains of fungi to synthetic fungicides while controlling effectively postharvest decay. PMID:23878974

  4. Prevenção de nefrotoxicidade por contraste com solução de bicarbonato: resultados preliminares e revisão da literatura Prevention of contrast-induced nephropathy by use of bicarbonate solution: preliminary results and literature review

    Directory of Open Access Journals (Sweden)

    Ricardo Gonçalves da Silva

    2010-09-01

    Full Text Available INTRODUÇÃO: A incidência da nefropatia por contraste tem aumentado simultaneamente ao aumento da sua utilização com fins diagnósticos e de intervenção terapêutica. A sua incidência na população geral é baixa, porém aumenta exponencialmente em pacientes com fatores de risco como diabetes e doença renal prévia. Várias estratégias têm sido utilizadas na tentativa de prevenir a nefropatia por contraste. Hidratação com solução fisiológica, contraste de baixa osmolalidade ou iso-osmolar e infusão de bicarbonato de sódio são consideradas como as mais eficazes. OBJETIVO: O objetivo deste trabalho é revisar a literatura pertinente sobre prevenção de nefropatia do contraste e estudar, de forma inicial, a eficácia da hidratação a base de bicarbonato de sódio a 1,3% comparada à hidratação a base de cloreto de sódio a 0,9% na prevenção da nefrotoxicidade do contraste em pacientes de alto risco para o seu desenvolvimento. MATERIAIS E MÉTODOS: Foi analisada a literatura por meio de busca sistemática no banco de dados PubMed usando as palavras-chave bicarbonato, nefrotoxicidade, contraste e insuficiência renal aguda e, adicionalmente, foram estudados 27 pacientes, portadores de diabetes mellitus e/ou doença renal crônica prévia e diagnosticados com algum tipo de câncer. RESULTADOS: Nenhum dos pacientes desenvolveu nefropatia do contraste, caracterizada como aumento de 0,5 mg/ dL e/ou de 25% na creatinina basal. CONCLUSÃO: A revisão de literatura sugere fortemente que o uso de bicarbonato de sódio é eficaz na prevenção de nefropatia por contraste. Em relação ao estudo randomizado e controlado o soro fisiológico e o bicarbonato de sódio apresentaram eficácia similar quanto à prevenção de nefrotoxicidade do contraste. No entanto, o pequeno número de pacientes não permite conclusões definitivas.INTRODUCTION: The incidence of contrast-induced nephropathy has increased simultaneously with the increase in contrast medium use in diagnostic and interventional procedures. The incidence of contrast-induced nephropathy in the general population is low, but increases exponentially in patients with risk factors, such as diabetes and chronic kidney disease. Several strategies have been used in order to prevent contrast-induced nephropathy. The most efficient strategies are saline hydration (0.9% or 0.45%, use of low-or iso-osmolality contrast medium, and sodium bicarbonate infusion. OBJECTIVE: The aim of this study was to review the pertinent literature and to assess the efficacy of hydration with 1.3% sodium bicarbonate compared with hydration with 0.9% saline solution in preventing contrastinduced nephropathy in high-risk patients. MATERIAL AND METHODS: A systematic search of the literature was conducted in PubMed by using the following keywords: bicarbonate, nephropathy, contrast medium, and acute kidney failure. In addition, 27 patients with diabetes and/or chronic kidney disease, diagnosed with some kind of cancer were randomized for study. RESULTS: None of the patients developed contrast-induced nephropathy characterized as a 0.5 mg/ dL-increase and/or a relative 25%-increase in baseline creatinine. CONCLUSIONS: The literature review strongly suggested that sodium bicarbonate is effective in preventing contrast-induced nephropathy. Regarding the randomized study, saline solution and bicarbonate solution had similar efficacy in preventing contrast-induced nephropathy. However, the small number of patients does not allow definite conclusions.

  5. Prevenção de nefrotoxicidade por contraste com solução de bicarbonato: resultados preliminares e revisão da literatura / Prevention of contrast-induced nephropathy by use of bicarbonate solution: preliminary results and literature review

    Scientific Electronic Library Online (English)

    Ricardo Gonçalves da, Silva; Nelson Gonçalves da, Silva; Fabiano, Lucchesi; Emmanuel A, Burdmann.

    2010-09-01

    Full Text Available INTRODUÇÃO: A incidência da nefropatia por contraste tem aumentado simultaneamente ao aumento da sua utilização com fins diagnósticos e de intervenção terapêutica. A sua incidência na população geral é baixa, porém aumenta exponencialmente em pacientes com fatores de risco como diabetes e doença ren [...] al prévia. Várias estratégias têm sido utilizadas na tentativa de prevenir a nefropatia por contraste. Hidratação com solução fisiológica, contraste de baixa osmolalidade ou iso-osmolar e infusão de bicarbonato de sódio são consideradas como as mais eficazes. OBJETIVO: O objetivo deste trabalho é revisar a literatura pertinente sobre prevenção de nefropatia do contraste e estudar, de forma inicial, a eficácia da hidratação a base de bicarbonato de sódio a 1,3% comparada à hidratação a base de cloreto de sódio a 0,9% na prevenção da nefrotoxicidade do contraste em pacientes de alto risco para o seu desenvolvimento. MATERIAIS E MÉTODOS: Foi analisada a literatura por meio de busca sistemática no banco de dados PubMed usando as palavras-chave bicarbonato, nefrotoxicidade, contraste e insuficiência renal aguda e, adicionalmente, foram estudados 27 pacientes, portadores de diabetes mellitus e/ou doença renal crônica prévia e diagnosticados com algum tipo de câncer. RESULTADOS: Nenhum dos pacientes desenvolveu nefropatia do contraste, caracterizada como aumento de 0,5 mg/ dL e/ou de 25% na creatinina basal. CONCLUSÃO: A revisão de literatura sugere fortemente que o uso de bicarbonato de sódio é eficaz na prevenção de nefropatia por contraste. Em relação ao estudo randomizado e controlado o soro fisiológico e o bicarbonato de sódio apresentaram eficácia similar quanto à prevenção de nefrotoxicidade do contraste. No entanto, o pequeno número de pacientes não permite conclusões definitivas. Abstract in english INTRODUCTION: The incidence of contrast-induced nephropathy has increased simultaneously with the increase in contrast medium use in diagnostic and interventional procedures. The incidence of contrast-induced nephropathy in the general population is low, but increases exponentially in patients with [...] risk factors, such as diabetes and chronic kidney disease. Several strategies have been used in order to prevent contrast-induced nephropathy. The most efficient strategies are saline hydration (0.9% or 0.45%), use of low-or iso-osmolality contrast medium, and sodium bicarbonate infusion. OBJECTIVE: The aim of this study was to review the pertinent literature and to assess the efficacy of hydration with 1.3% sodium bicarbonate compared with hydration with 0.9% saline solution in preventing contrastinduced nephropathy in high-risk patients. MATERIAL AND METHODS: A systematic search of the literature was conducted in PubMed by using the following keywords: bicarbonate, nephropathy, contrast medium, and acute kidney failure. In addition, 27 patients with diabetes and/or chronic kidney disease, diagnosed with some kind of cancer were randomized for study. RESULTS: None of the patients developed contrast-induced nephropathy characterized as a 0.5 mg/ dL-increase and/or a relative 25%-increase in baseline creatinine. CONCLUSIONS: The literature review strongly suggested that sodium bicarbonate is effective in preventing contrast-induced nephropathy. Regarding the randomized study, saline solution and bicarbonate solution had similar efficacy in preventing contrast-induced nephropathy. However, the small number of patients does not allow definite conclusions.

  6. The origin of recharge waters and their evolution into effervescent sodium-bicarbonate groundwater from the Ballimore region, central New South Wales: oxygen and hydrogen isotope data

    International Nuclear Information System (INIS)

    Oxygen-18 and deuterium stable isotopic data were used to investigate the origin of water recharging the Ballimore region's groundwater system. The sodium-bicarbonate-rich groundwater (soda-water) is of meteoric origin with both ?18O and ?D values being shifted to the left of Global Meteoric Water Line. This shift is linked to the influx of mixed mantle-magmatic CO2 gas: the ?18O depletion in the soda-water is interpreted to result from isotopic exchange between groundwater and CO2 gas. The local flow system is shown to be open to the influx of CO2 with the gas being of mixed mantle-magmatic origin. The more saline Na-HCO3 groundwaters have the lowest ?18O and ?D values. Additionally weathering of aluminosilicates and precipitation of kaolinite further depletes the groundwater in both ?18O and D. The stable isotope data support the interpreted major ion chemical processes and ?13C data show that fractionation related to CO2 gas exchange produces groundwater with depleted ?18O and ?D values

  7. Crystal growth of calcite from calcium bicarbonate solutions at constant PCO2 and 25°C: a test of a calcite dissolution model

    Science.gov (United States)

    Reddy, Michael M.; Plummer, L. Neil; Busenberg, E.

    1981-01-01

    A highly reproducible seeded growth technique was used to study calcite crystallization from calcium bicarbonate solutions at 25°C and fixed carbon dioxide partial pressures between 0.03 and 0.3 atm. The results are not consistent with empirical crystallization models that have successfully described calcite growth at low PCO2 (crystallization rates and those calculated from the calcite dissolution rate law and mechanism proposed by Plummer et al. (1978).

  8. Hydration and ion pairing in aqueous sodium oxalate solutions.

    Science.gov (United States)

    Buchner, Richard; Samani, Faradj; May, Peter M; Sturm, Peter; Hefter, Glenn

    2003-04-14

    Dielectric spectra have been measured for aqueous sodium oxalate solutions up to the saturation concentration (0.04 frequency range 0.2 Eigen theory, consistent with a 2SIP structure for the ion pair. PMID:12728552

  9. The carbon source for effervescent sodium-bicarbonate groundwater in the Ballimore region, central New South Wales

    International Nuclear Information System (INIS)

    This paper describes the integrated use of stable isotopic (?13C) data for delineating the origin of carbon in groundwater systems. Groundwater in the Ballimore region is unusual: the main interests of this study are artesian boreholes that produce effervescent Na-HCO3 (soda) waters. Carbon-dioxide gas is present in concentrations of up to 1g/l, and CO2 partial pressures are one thousand times higher than atmospheric levels. Major-ion geochemical interpretation indicates that the evolution of the effervescent Na-HCO3-rich groundwater in the region relies on fresh water entering the deep cell of the local flow system from Late Jurassic depocentres that are filled with fresh water. This groundwater flows S-SE through the fracture network that constitutes the deep cell of the local groundwater system. As it travels along the flowpath it mixes with CO2(g): decreasing the groundwater pH and making it chemically aggressive. When this water comes into contact with Late Miocene (?), sodium-rich intrusive rocks along flow path, sodic silicates (probably nepheline) weather to form kaolinite, this reaction produces a Na:HCO3 ratio (in mmol/l) of unity. Stable isotopic data from rock samples and groundwater collected throughout the Ballimore region provide support for the interpreted major-ion chemical evolution of effervescent Na-HCO3-rich groundwater. Carbon isotope data helps constrain the source of carbon in this system

  10. Corrosion of dental amalgams in solutions of sodium chloride, sodium sulfide and ammonia.

    Science.gov (United States)

    Palaghias, G

    1986-06-01

    Specimens were prepared from three different dental amalgams and were immersed in 0.5% aqueous solutions of sodium sulfide, ammonia and sodium chloride. Every month and over a 6-month experimental period the solutions were replaced with fresh electrolyte and were analyzed in an atomic absorption spectrophotometer with respect to their content in silver, mercury, copper, tin and zinc. In sulfide solutions large amounts of tin and mercury were released from the amalgams while none of the other elements could be detected. Copper, tin and mercury were mostly dissolved in ammonia solutions. An increased silver dissolution could also be observed. Zinc was the first element to be released in sodium chloride solutions. After a 4-month immersion, considerable amounts of copper and mercury could also be found in the same solutions. PMID:3461549

  11. Bicarbonate exporting transporters in the ovine ruminal epithelium.

    Science.gov (United States)

    Bilk, S; Huhn, K; Honscha, K U; Pfannkuche, H; Gäbel, G

    2005-07-01

    In order to stabilize the intraruminal pH, bicarbonate secretion by the ruminal epithelium seems to be an important prerequisite. The present study therefore focussed on the characterization of bicarbonate exporting systems in ruminal epithelial cells. Intracellular pH (pH(i)) was measured spectrofluorometrically in primary cultured ruminal epithelial cells loaded with the pH-sensitive fluorescent dye, 2,7-bis(carboxyethyl)-5(6')-carboxyfluorescein acetomethyl ester. Switching from CO2/HCO3- -buffered to HEPES-buffered solution caused a rapid intracellular alkalinization followed by a counter-regulation towards initial pH(i). The recovery of pH(i) was dependent upon extracellular chloride, but independent of extracellular sodium. Adding 500 microM H2DIDS significantly reduced the increase of pH(i). For further characterization of the bicarbonate exporting systems, we tested the ability to reverse the direction from HCO3- export to import in the absence of sodium and chloride. Under sodium and chloride-free conditions, counter-regulation after CO2-induced pH(i) decrease did not differ from pH(i) recovery in the presence of sodium and chloride. Existence of bicarbonate exporting systems in cultured ruminal epithelial cells and intact ruminal epithelium was verified by reverse transcription polymerase chain reaction (RT-PCR). Using RT-PCR and subsequent sequencing, expression of mRNA encoding for AE2, DRA and PAT1 could be found. Bicarbonate exporting systems could therefore be detected both on the functional and structural level. PMID:15926041

  12. Sodium carbonate-bicarbonate leaching of a New Mexico uranium ore and removal of long half-life radionuclides from the leach residue

    International Nuclear Information System (INIS)

    The present study demonstrates the possibility to develop an efficient carbonate-bicarbonate leaching process for the extraction of uranium from a low-grade ore. In this process uranium extraction is coupled with the removal of radionuclides from the leach residue to yield environmentally safe and radiochemically innocuous tailings. Radionuclides are concentrated in small volumes and stored under controlled containment until uses for the radioisotopes are found. The influence of leach parameters Na2CO3, NaHCO3, pulp density, agitation, temperature and oxygen pressure was assessed. Uranium extractions as high as 96% were obtained at atmospheric air pressure with leach suspensions containing 20% pulp density at 750C in 2 h of leaching and at 1700 kPa oxygen pressure with 10% pulp density leach suspensions at 750C in 1.5 h. The activation energy was calculated to be ?Esub(a) = 18.8 kJ mol-1, which suggests a diffusion-controlled mechanism for uranium extraction. Using leach residues of carbonate leaching and brine solutions containing HCl and CaCl2, the highest extraction of radionuclides was approximately 79% of Th-230, 91% of Ra-226 and 69% of Pb-210. The selective extraction of Ra-226 from the brine-containing leach solution was demonstrated with barium-loaded organic solid ion exchangers. (orig.)

  13. Degradation of Organophosphorus Pesticides in Water during UV/H2O2 Treatment: Role of Sulphate and Bicarbonate Ions

    OpenAIRE

    Fadaei, AM; Dehghani, Mh; Mahvi, AH; S Nasseri; Rastkari, N.; M Shayeghi

    2012-01-01

    The photodegradation of two organophosphorus pesticides, malathian and diazinon, by sulfate radicals and bicarbonate radicals in aqueous solution were studied. The effect of the operational parameters such as pH, salt concentration, water type, H2O2 concentration and initial concentration of pesticides was studied. Gas chromatography mass spectroscopy (GC–MS) was used for analyses of pesticides. When salt effect was studied, it was found that sodium bicarbonate was the most powerful inhibitor...

  14. Photochemical oxidation of Am(III) in bicarbonate-carbonate solutions by BrO3-, ClO3-, and IO3-

    International Nuclear Information System (INIS)

    A new photochemically active oxidant of Am in bicarbonate-carbonate (HCO3--CO2-3) solutions, BrO3-, is discovered. In solutions containing BrO3-, Am(III) (up to 10-3 M), and a mixture of bicarbonate and carbonate ions in a definite ratio (pH from 8.4 to 10.5) and at a total concentration greater than 1 M, Am(III) is quantitatively oxidized to Am(IV) on irradiation by UV light for several minutes. Quantum yield of the reaction is 20-30% depending on the conditions. The features of the oxidation are practically the same in Na and K HCO3--CO2-3 solutions. The rate of Am(III) oxidation slightly decreases as the pH or the total [HCO3-] + [CO2-3] increase. The oxidation is zero-order in Am. In CO32- solutions that do not contain HCO3-, Am is quantitatively oxidized by BrO3- to Am(VI). The ions ClO3- and IO3- can only partially oxidize Am(III) to Am(IV) in HCO3--CO32- solutions and cannot oxidize it to Am(VI) in CO32- solutions

  15. Tetragonal Chicken Egg White Lysozyme Solubility in Sodium Chloride Solutions

    Science.gov (United States)

    Forsythe, Elizabeth L.; Judge, Russell A.; Pusey, Marc L.

    1998-01-01

    The solubility of chicken egg white lysozyme, crystallized in the tetragonal form was measured in sodium chloride solutions from 1.6 to 30.7 C, using a miniature column solubility apparatus. Sodium chloride solution concentrations ranged from 1 to 7% (w/v). The solutions were buffered with 0.1 M sodium acetate buffer with the solubility being measured at pH values in 0.2 pH unit increments in the range pH 4.0 to 5.4, with data also included at pH 4.5. Lysozyme solubility was found to increase with increases in temperature and decreasing salt concentration. Solution pH has a varied and unpredictable effect on solubility.

  16. On vanadium oxide dissolution in sodium carbonate solutions

    International Nuclear Information System (INIS)

    Kinetics of dissolution process of powdered vanadium (5) oxide in sodium carbonate is studied. Activation energy of chemical dissolution of V2O5 at sodium carbonate concentration up to 0.6 mol/dm3 constitutes 35.2 kJ/mol. With sodium carbonate concentration increase the dissolution activation energy decreases to 32.5 kJ/mol. Absolute values of activation energy of the dissolution process, dependence of the reaction order on the temperature in the range of low sodium carbonate concentration, testify to the presence of kinetic difficulties in the process studied. Thus, the process of V2O5 dissolution in sodium carbonate solutions proceeds in the mixed region and obeys regularities of the mixed kinetics

  17. Sodium Hydroxide Extraction From Caustic Leaching Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, Gregg J.; Garza, Priscilla A.; Levitskaia, Tatiana G.; Brown, Gilbert M.

    2002-09-18

    This report describes experiments conducted to demonstrate the proof-of-principle of a method to recover NaOH from Hanford tank sludge leaching solutions. Aqueous solutions generated from leaching actual Hanford tank waste solids were used. The process involves neutralization of a lipophilic weak acid (t-octylphenol was used in these experiments) by reaction with NaOH in the aqueous phase. This results in the transfer of Na into the organic phase. Contacting with water reverses this process, reprotonating the lipophilic weak acid and transferring Na back into the aqueous phase as NaOH. The work described here confirms the potential application of solvent extraction to recover and recycle NaOH from solutions generated by leaching Hanford tank sludges. Solutions obtained by leaching sludges from tanks S-110 and T-110 were used in this work. It was demonstrated that Na+ is transferred from caustic leaching solution to the organic phase when contacted with t-octylphenol solutions. This was accompanied by a concomitant decrease in the aqueous-phase hydroxide ion concentration. Seventy to 80 % of the extracted Na was recovered by 3 to 4 sequential contacts of the organic phase with water. Cesium was co-extracted by the procedure, but Al and Cr remained in the feed stream.

  18. Examination of rheological properties of aqueous solutions of sodium caseinate

    Directory of Open Access Journals (Sweden)

    Jolanta Gawałek

    2012-12-01

    Full Text Available Application of sodium caseinate as a functional additive in manufacturing processes requires production of its concentrated aqueous solutions which, in industrial conditions, presents a number of difficulties. In order to develop an effective and optimal industrial process of mixing – manufacturing a concentrated solution of sodium caseinate, it is essential to know rheological properties in a definite range of concentrations changing in the course of the dissolving process. The material for investigations was typical commercial sodium caseinate in the form of dry powder manufactured in Poland from acid casein using the method of extrusion. The objective of the undertaken empirical studies was the assessment of the impact of the concentration on rheological properties of sodium caseinate concentrates. Investigations were carried out for five concentrates manufactured in a mixer equipped in a mechanical agitator at concentrations ranging X (% Î (2.5¸12.5 and changing mass proportions of sodium caseinate in the aqueous solution as follows: GS/G (kgS·kg-1 = 0.025. On the basis of the obtained research results, classical flow curves were plotted for individual concentrates. The determined values of viscosity and density of the examined solutions were correlated in the form of h = f(GS/G and r = f(GS/G dependencies which were used during the determination of classical characteristics of mixing forces essential for the assessment of energetic expenditures required to manufacture concentrates in a mixer equipped in a mechanical agitator. The density of the examined concentrates increased in a way directly proportional, while the dynamic viscosity coefficient increased exponentially together with the increase of sodium caseinate concentration. Sodium caseinate concentrates exhibited Newtonian character in the examined range of concentrations.

  19. Solubility of sodium soaps in aqueous salt solutions.

    Science.gov (United States)

    Lin, Bin; McCormick, Alon V; Davis, H Ted; Strey, Reinhard

    2005-11-15

    The solubility of sodium soaps in dilute aqueous salt solutions has been systematically investigated by direct visual phase behavior observations. The added electrolytes, including simple inorganic salts and bulky organic salts, influence the solubility of sodium soaps in water, as represented by the varied soap Krafft point. Two inorganic salts, sodium chloride and sodium perchlorate, demonstrate a "salting-out" property. On the other hand, tetraalkylammonium bromides show an excellent ability to depress the soap Krafft point and enhance the soap solubility in water. With increasing the tetraalkylammonium ionic size, the degree of "salting-in" of soaps in water increases. However, solubility of pure tetraalkylammonium bromide in water decreases as the length of the alkyl chains increases. Furthermore, in the ternary water-tetrapentylammonium bromide (TPeAB)-sodium myristate (NaMy) system, we observed an upper cloud point phenomenon, which greatly shrinks the 1-phase micellar solution region in the phase diagram. This miscibility gap, together with the organic salt solubility limitation, restricts the use of tetraalkylammonium bromides with alkyl chains longer than 4 carbon atoms as effective soap solubility enhancement electrolytes. We also found that for sodium soap with a longer hydrocarbon chain, more tetrabutylammonium salt is required to reduce the soap Krafft point to room temperature. PMID:15979632

  20. [Serious risk related to oral use of sodium phosphate solution].

    Science.gov (United States)

    Hoffmanová, I; And?l, M

    2013-12-01

    Sodium phosphate solutions are commonly used to cleanse the bowel in preparation for colonoscopy, for barium enema or surgical procedures and eventually for treatment of severe constipation. Though relatively safe, these drugs must be used with caution in patients with kidney disease, small intestinal disorders, or poor gut motility and are prohibited in renal insufficiency and bowel obstruction. Especially elderly patients are at increased risk for phosphate intoxication due to decreased glomerular filtration rate, concomitant medication use, and systemic and gastrointestinal diseases. Sodium phosphate solution could induce by at-risk patients serious electrolyte abnormalities (hyperphosphatemia, hypocalcemia, hypokalemia) and acute kidney injury called acute phosphate nephropathy, which is potentially life-threatening condition with slowly progressive renal insufficiency. This article gives a report on two cases of severe adverse effects after administration of oral sodium phosphate solution: an elderly women who developed increase in serum phosphate with compensatory severe hypokalcemia with tetany; and an elderly man who developed acute phosphate nephropathy following colon preparation prior to colonoscopy and barium enema. Especially in elderly and in patients in whom sodium phosphate solution is contraindicated or should be used with caution, we recommend to use isosmotic macrogol (polyethylene glycol) solution for the bowel cleansing a for the treatment of constipation. PMID:24350942

  1. BY THE MECHANOACTIVATION OF SOLUTION OF THE SODIUM SILICATE

    Directory of Open Access Journals (Sweden)

    Fedosov Sergey Viktorovich

    2012-09-01

    Full Text Available Mixing of cement by the mechanoactivation of the sodium liquid glass solution resulted in increasing of the heat stability and the compressive and flexural strengths of cement stone and reducing of the water adsorption. These data point to compacting of cement stone structure.

  2. Ionization of methyl orange in aqueous sodium chloride solutions

    International Nuclear Information System (INIS)

    Highlights: ? Thermodynamic ionization constant of methyl orange in the temperature range (278.15 to 333.15 K). ? Influence of sodium chloride on the ionization of methyl orange. ? Pitzer interaction coefficients for methyl orange (sodium salt). ? Ionic strength dependence of the stoichiometric ionization constant. - Abstract: Ionization constants of sodium 4?-dimethylaminoazobenzene-4-sulphonate (methyl orange) were determined by means of spectrophotometric measurements in water and in aqueous sodium chloride solutions with molalities up to 2 mol·kg?1 at temperatures between 278.15 K and 333.15 K. The temperature dependence of the thermodynamic acidity constant shows a slight curvature in accordance with published data. The influence of sodium chloride on the methyl orange deprotonation was assessed by the measurement of stoichiometric acidity constants in this ionic medium. The Pitzer theory, widely used in the evaluation of the excess free energy of non-ideal electrolyte solutions, was applied to the computation of the activity coefficients of the chemical species involved in the equilibria and a good fit of those equations to the experimental data was observed, at all temperatures under consideration.

  3. On the texturization of monocrystalline silicon with sodium carbonate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vallejo, B.; Gonzalez-Manas, M.; Martinez-Lopez, J.; Caballero, M.A. [Departamento de Cristalografia, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real (Spain)

    2007-05-15

    The texturization of monocrystalline silicon wafers using sodium carbonate solution has been investigated. This etching process has been evaluated in terms of the surface morphology and the reflectance value. The results show that for low concentration of sodium carbonate the increase of texturing time decreases the reflectance value because of the change in morphology from hillocks to pyramidal; on the contrary for intermediate and high concentrations the increase of time has a detrimental effect on texturization because it increases both the pyramid sizes and their non-uniform distribution. However, a good cell performance could be obtained by etching at high concentrations and short times. (author)

  4. Corrosion behaviour of Alloy 800 in high temperature aqueous solutions: Electrochemical studies

    International Nuclear Information System (INIS)

    The anodic behaviour and passivity breakdown of Alloy 800 in aqueous solutions of sodium chloride, sodium sulphate and sodium bicarbonate were studied by electrochemical techniques in the temperature range from 60 C to 280 C. The pitting resistance and pitting morphology of the alloy in chloride plus sulphate and chloride plus bicarbonate mixtures, at 60 C and 280 C, were also examined. Increasing bicarbonate or sulphate additions to chloride solutions shift the characteristic pitting potential of Alloy 800 to higher values, both at low and high temperatures. Changes in pitting morphology were observed in sulphate containing solutions while the morphology of the attack found in bicarbonate containing solutions was similar to that in pure chloride solutions. Finally, no localized or substantial generalized corrosion was detected in pure sulphate or bicarbonate solutions at any temperature. (orig.)

  5. A study of X100 pipeline steel passivation in mildly alkaline bicarbonate solutions using electrochemical impedance spectroscopy under potentiodynamic conditions and Mott-Schottky

    Science.gov (United States)

    Gadala, Ibrahim M.; Alfantazi, Akram

    2015-12-01

    The key steps involved in X100 pipeline steel passivation in bicarbonate-based simulated soil solutions from the pre-passive to transpassive potential regions have been analyzed here using a step-wise anodizing-electrochemical impedance spectroscopy (EIS) routine. Pre-passive steps involve parallel dissolution-adsorption in early stages followed by clear diffusion-adsorption control shortly before iron hydroxide formation. Aggressive NS4 chlorides/sulfate promote steel dissolution whilst inhibiting diffusion in pre-passive steps. Diffusive and adsorptive effects remain during iron hydroxide formation, but withdraw shortly thereafter during its removal and the development of the stable iron carbonate passive layer. Passive layer protectiveness is evaluated using EIS fitting, current density analysis, and correlations with semiconductive parameters, consistently revealing improved robustness in colder, bicarbonate-rich, chloride/sulfate-free conditions. Ferrous oxide formation at higher potentials results in markedly lower impedances with disordered behavior, and the involvement of the iron(III) valence state is observed in Mott-Schottky tests exclusively for 75 °C conditions.

  6. Sodium bicarbonate as prevention of metabolic acidosis in sheep submitted to experimental ruminal acidosis / Bicarbonato de sódio como preventivo da acidose metabólica em ovinos submetidos à acidose ruminal experimental

    Scientific Electronic Library Online (English)

    Luciane M., Laskoski; Lívia S., Muraro; Marinho S., Santana Júnior; Mariana B., Carvalho; Silvio H., Freitas; Renata G.S., Dória; Marcelo D., Santos; Rosangela Locatelli, Dittrich.

    2014-09-01

    Full Text Available O objetivo deste estudo foi avaliar o efeito preventivo do bicarbonato de sódio sobre a acidose sistêmica em decorrência da acidose ruminal, a qual foi induzida pelo fornecimento de concentrado após jejum prolongado. Foram utilizados 14 ovinos, divididos em três grupos experimentais: grupo controle [...] (Cg), contendo quatro ovinos, submetidos a jejum sem desenvolvimento de acidose ruminal; grupo não tratado (NTg), contendo cinco ovinos submetidos a acidose ruminal sem tratamento preventivo; e grupo tratado (Tg), contendo cinco ovinos, submetidos a acidose ruminal e tratados preventivamente com bicarbonato de sódio. Foram realizadas avaliações do pH ruminal e hemogasometria arterial, durante 48 horas após o fornecimento do concentrado. Houve redução do pH ruminal em todos os grupos, sendo que o Cg apresentou a redução apenas às 24 horas. Notou-se redução do pH arterial, bicarbonato e excesso de base em todos os grupos, indicando acidose metabólica sistêmica; no entanto, o NTg apresentou o quadro mais grave. Conclui-se que o bicarbonato de sódio possui efeito preventivo da acidose metabólica sistêmica, reduzindo a sua gravidade em ovinos submetidos à acidose ruminal. Abstract in english The aim of this study was to evaluate the preventive effect of sodium bicarbonate on systemic acidosis due to ruminal acidosis, which was induced by ingestion of concentrate after prolonged fasting. Fourteen sheep were divided into three experimental groups: control group (Cg), with four sheep, subm [...] itted to fasting without development of ruminal acidosis; no-treated group (NTg), with five sheep with rumen acidosis without preventive treatment; and treated group (Tg), with five sheep with rumen acidosis and preventively treated with sodium bicarbonate. Assessments of ruminal pH and arterial hemogasometry were performed for 48 hours after ingestion of the concentrate. There was a reduction in the ruminal pH in all groups, whereas the Cg showed a reduction only after 24 hours. A reduction in the arterial pH, bicarbonate and base excess in all groups was also noted, indicating systemic metabolic acidosis, but the NTg presented the greatest alteration. It is concluded that sodium bicarbonate prevents systemic metabolic acidosis, reducing its severity in sheep subjected to ruminal acidosis.

  7. Electrochemical Recovery of Sodium Hydroxide from Alkaline Salt Solution

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.T. [Westinghouse Savannah River Company, AIKEN, SC (United States); Edwards, T.B.

    1996-10-01

    A statistically designed set of tests determined the effects of current density, temperature, and the concentrations of nitrate/nitrite, hydroxide and aluminate on the recovery of sodium as sodium hydroxide (caustic) from solutions simulating those produced from the Savannah River Site (SRS) In-Tank Precipitation process. These tests included low nitrate and nitrite concentrations which would be produced by electrolytic nitrate/nitrite destruction. The tests used a two compartment electrochemical cell with a Nafion Type 324 ion-exchange membrane. Caustic was successfully recovered from the waste solutions. Evaluation of the testing results indicated that the transport of sodium across the membrane was not significantly affected by any of the varied parameters. The observed variance in the sodium flux is attributed to experimental errors and variations in the performance characteristics of individual pieces of the organic-based Nafion membrane.Additional testing is recommended to determine the maximum current density, to evaluate the chemical durability of the organic membrane as a function of current density and to compare the durability and performance characteristics of the organic-based Nafion membrane with that of other commercially available organic membranes and the inorganic class of membranes under development by Ceramatec and PNNL.

  8. Molybdenum recovery from sulfide ores by alkali sodium hypochlorite solution

    International Nuclear Information System (INIS)

    The specified kinetic characteristics of hydrochemical oxidation of molybdenite by sodium hypochlorite are discussed. The methods of hypochlorite synthesis, Mo recovery from solutions after leaching are selected. It is shown that the most acceptable method of preparing hypochlorite should be considered the NaCl solution electrolysis. Mo recovery from solutions after leaching has been performed by sorption on V-P-1p anionite, eluated from resin by 10% solution of ammonia, commodity product has been extracted in a form of ammonium polymolybdate. A principle flowsheet of Mo recovery from sulfide ores is suggested. The flowsheet has been tested under laboratory conditions. It ensures a closed cycle of leaching solution circulation and meets the requirements of environment control

  9. Positronium lifetime studies in aqueous sodium dodecyl sulphate micellar solutions

    International Nuclear Information System (INIS)

    Positronium lifetime measurements were performed in aqueous SDS (sodium dodecyl sulphate) solutions at different temperatures. The o-Ps (orthopositronium) lifetime shows monotonous increase vs. surfactant concentration and temperature. Results are explained by a simple model based on o-Ps diffusion and on the residence probability of o-Ps atoms in micelles; a lower boundary for o-Ps diffusion coefficient in the solvent was estimated. (author)

  10. Kinetics of gibbsite leaching in sodium hydroxide aqueous solution

    Directory of Open Access Journals (Sweden)

    Pavlovi? Ljubica J.

    2002-01-01

    Full Text Available In order to study the kinetics and mechanism of the reaction, laboratory leaching was carried out with industrially produced gibbsite ?-Al(OH3 in aqueous solutions containing an excess of sodium hydroxide. The results obtained reaction temperature, duration and base concentration varied. The basic kinetic parameters were determined from: the reaction rate constant k=8.72·107 exp (-74990/RT and the process activation energy in the range Ea=72.5-96.81 kJ/mol.

  11. In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate / Eficiência antimicrobiana in vitro de um enxaguatório bucal contendo triclosan/gantrez e bicarbonato de sódio

    Scientific Electronic Library Online (English)

    Juliana Rico, Pires; Carlos, Rossa Junior; Antonio Carlos, Pizzolitto.

    2007-12-01

    Full Text Available Diversas substâncias antisépticas têm sido utilizadas como adjuntos aos procedimentos mecânicos rotineiros de higiene oral, com base em seus efeitos antimicrobianos. O objetivo deste estudo foi avaliar, in vitro, a eficiência antimicrobiana de um enxaguatório bucal contendo Triclosan/Gantrez e bicar [...] bonato de sódio, em comparação a controles positivos e negativos. Linhagens padrão de Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus e Bacillus subtilis foram utilizadas. Amostras de Streptococcus mutans e Bacilos Gram-negativos foram coletadas de 20 voluntários (10 com um periodonto clinicamente saudável e 10 com gengivite associada à presença de biofilme). A avaliação da atividade antimicrobiana foi realizada pela determinação da Concentração Inibitória Mínima (CIM). Os resultados mostraram que a solução teste inibiu o crescimento de microrganismos Gram-negativos e Gram-positivos da saliva dos voluntários, bem como das linhagens padrão na CIM de 1:20, enquanto que a CIM da diluição de clorexidina 0.12% contra as mesmas bactérias foi de 1:80. Desta forma, apesar de o enxaguatório bucal testado apresentar atividade antimicrobiana in vitro superior à do placebo, esta foi inferior à da Clorexidina. Abstract in english Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of a mouthwash containing Triclosan/Gantrez and sodium bicarbonate in compa [...] rison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis). Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC). The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers’ saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12% chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.

  12. In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate Eficiência antimicrobiana in vitro de um enxaguatório bucal contendo triclosan/gantrez e bicarbonato de sódio

    Directory of Open Access Journals (Sweden)

    Juliana Rico Pires

    2007-12-01

    Full Text Available Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of a mouthwash containing Triclosan/Gantrez and sodium bicarbonate in comparison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis. Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC. The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers’ saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12% chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.Diversas substâncias antisépticas têm sido utilizadas como adjuntos aos procedimentos mecânicos rotineiros de higiene oral, com base em seus efeitos antimicrobianos. O objetivo deste estudo foi avaliar, in vitro, a eficiência antimicrobiana de um enxaguatório bucal contendo Triclosan/Gantrez e bicarbonato de sódio, em comparação a controles positivos e negativos. Linhagens padrão de Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus e Bacillus subtilis foram utilizadas. Amostras de Streptococcus mutans e Bacilos Gram-negativos foram coletadas de 20 voluntários (10 com um periodonto clinicamente saudável e 10 com gengivite associada à presença de biofilme. A avaliação da atividade antimicrobiana foi realizada pela determinação da Concentração Inibitória Mínima (CIM. Os resultados mostraram que a solução teste inibiu o crescimento de microrganismos Gram-negativos e Gram-positivos da saliva dos voluntários, bem como das linhagens padrão na CIM de 1:20, enquanto que a CIM da diluição de clorexidina 0.12% contra as mesmas bactérias foi de 1:80. Desta forma, apesar de o enxaguatório bucal testado apresentar atividade antimicrobiana in vitro superior à do placebo, esta foi inferior à da Clorexidina.

  13. Potentiometric monitoring of sodium borohydride in aqueous solutions

    Scientific Electronic Library Online (English)

    Diogo M. F., Santos; César A. C., Sequeira.

    2008-12-01

    Full Text Available Platina, paládio, ouro, cádmio, níquel e nióbio imersos em soluções alcalinas de borohidreto de sódio são caracterizados por respostas de eléctrodo que permitem monitorizar o conteúdo em borohidreto presente num dado meio aquoso. Descreve-se uma técnica de titulação potenciométrica relativamente sim [...] ples e precisa que pode ser aplicada para a análise de soluções de borohidreto. Abstract in english Platinum, palladium, gold, cadmium, nickel and niobium immersed in sodium borohydride alkaline solutions are characterised by electrode responses that allow monitoring the borohydride present in aqueous media. A simple and relatively precise potentiometric titration technique is described and applie [...] d for the analysis of borohydride solutions.

  14. Measurements of the viscosity of sodium tetraborate (borax)-UO2 and of sodium metaborate-UO2 liquid solutions

    International Nuclear Information System (INIS)

    Adding UO2 produces an increase of viscosity of borax and sodium metaborate. For temperatures below 9200C the measurements with the borax-UO2 solution show a phase separation. Contrary to borax the sodium metaborate solutions indicate a well defined melting point. At temperatures slightly below the melting point a solid phase is formed. The tested sodium-borates-UO2 mixtures are in liquid form. (DG)

  15. Cost of producing U3O8 from ammonium bicarbonate in situ leach solution by the multiple-compartment ion-exchange system

    International Nuclear Information System (INIS)

    The Bureau of Mines estimated the cost for a uranium ion-exchange recovery system using five grades of U3O8 leach solution producing 815,570 pounds of U3O8 per year from an ammonium bicarbonate in situ leach solution. The system flowsheet consisted of four unit operations: (1) Multiple-compartment ion-exchange (MCIX) absorption; (2) MCIX elution; (3) precipitation of the uranium as yellow cake, filtering, calcining, and packaging; and (4) waste disposal. The total fixed capital cost of a system treating 2,000 gallons per minute of 0.1-gram-per-liter-U3O8 leach solution was estimated as $6,888,000. For a basic case of an MCIX system depreciating in 9 years, unit production cost of U3O8 was $3.51 per pound. A decrease in feed solution grade from 0.4 to 0.03 gram per liter increased the production cost exponentially. Shorter depreciating periods significantly increased the production cost particularly for the lower grade feed solutions

  16. Radiolytic oxidation behavior of neptunium in sodium chloride solutions

    International Nuclear Information System (INIS)

    Radiolytic oxidation behavior of neptunium was investigated in order to predict its migration behavior at the disposal site for radioactive waste. Neptunium, in 5 mol/dm3 sodium chloride solutions of several pH values, was irradiated by ?-particles of 238Pu which had been placed in the solutions as dioxide powder. Solution neptunium redox behavior was compared with that of an unirradiated sample. Pentavalent neptunium, which was stable in the absence of 238Pu, was found to be oxidized to hexavalent and even to heptavalent neptunium. Oxidizing species would be chloride molecule anion (Cl2-) and/or hypochlorite anion (ClO-) which were generated by the reaction between radiolytically generated hydroxide radical (OH) and chloride ion (Cl-). The oxidation rate of pentavalent neptunium was independent of its concentration, but dependent on solution pH. The measured rate constant was (19±4)[H] mol/dm3/d. (author)

  17. Magnetite stability in aqueous sodium phosphate solutions at elevated temperatures

    International Nuclear Information System (INIS)

    Magnetite (Fe3O4) is shown to transform to a sodium ferric hydroxyphosphate compound in concentrated, alkaline sodium phosphate solutions at elevated temperatures via 1/3 Fe3O4(s) + 133 Na+ + 2 HPO+4 left-reversible Na4Fe(OH)(PO4)2·31NaOH(s) + 13H+ + 16H2(g). The thermodynamic equilibrium for this reaction was defined in the system Na2OP2O5-Fe3O4-H2O for Na/P molar ratios between 2.1 and 3. Quantitative chemical, infrared and Moessbauer spectroscopic, and X-ray diffraction analysis are employed to verify that the precipitated solid was a single phase having the non-whole number stoichiometric Na/P ratio = 2.15 ± 0.02. On the basis of observed reaction threshold values for sodium phosphate concentration and temperature, the standard entropy (S0) and free energy of formation (?G01) for sodium ferric hydroxyphosphate were calculated to be 729.2 J/(mol-K) and -3550.3 Kh/mol, respectively

  18. Photoionization of Sodium Salt Solutions in a Liquid Jet

    International Nuclear Information System (INIS)

    A liquid microjet was employed to examine the gas/liquid interface of aqueous sodium halide (Na+X-, X=Cl, Br, I) salt solutions. Laser excitation at 193 nm produced and removed cations of the form H+(H2O)n and Na+(H2O)m from liquid jet surfaces containing either NaCl, NaBr or NaI. The protonated water cluster yield varied inversely with increasing salt concentration, while the solvated sodium ion cluster yield varied by anion type. The distribution of H+(H2O)n at low salt concentration is identical to that observed from low-energy electron irradiated amorphous ice and the production of these clusters can be accounted for using a localized ionization/Coulomb expulsion model. Production of Na+(H2O)m is not accounted for by this model but requires ionization of solvation shell waters and a contact ion/Coulomb expulsion mechanism. The reduced yields of Na+(H2O)m from high concentration (10-2 and 10-1 M) NaBr and NaI solutions indicate a propensity for Br- and I- at the solution surfaces and interfaces. This is supported by the observation of multiphoton induced production and desorption of Br+ and I+ from the 10-2 and 10-1 M solution surfaces

  19. SODIUM ALUMINOSILICATE FOULING AND CLEANING OF DECONTAMINATED SALT SOLUTION COALESCERS

    International Nuclear Information System (INIS)

    During initial non-radioactive operations at the Modular Caustic Side Solvent Extraction Unit (MCU), the pressure drop across the decontaminated salt solution coalescer reached ?10 psi while processing ?1250 gallons of salt solution, indicating possible fouling or plugging of the coalescer. An analysis of the feed solution and the 'plugged coalescer' concluded that the plugging was due to sodium aluminosilicate solids. MCU personnel requested Savannah River National Laboratory (SRNL) to investigate the formation of the sodium aluminosilicate solids (NAS) and the impact of the solids on the decontaminated salt solution coalescer. Researchers performed developmental testing of the cleaning protocols with a bench-scale coalescer container 1-inch long segments of a new coalescer element fouled using simulant solution. In addition, the authors obtained a 'plugged' Decontaminated Salt Solution coalescer from non-radioactive testing in the MCU and cleaned it according to the proposed cleaning procedure. Conclusions from this testing include the following: (1) Testing with the bench-scale coalescer showed an increase in pressure drop from solid particles, but the increase was not as large as observed at MCU. (2) Cleaning the bench-scale coalescer with nitric acid reduced the pressure drop and removed a large amount of solid particles (11 g of bayerite if all aluminum is present in that form or 23 g of sodium aluminosilicate if all silicon is present in that form). (3) Based on analysis of the cleaning solutions from bench-scale test, the 'dirt capacity' of a 40 inch coalescer for the NAS solids tested is calculated as 450-950 grams. (4) Cleaning the full-scale coalescer with nitric acid reduced the pressure drop and removed a large amount of solid particles (60 g of aluminum and 5 g of silicon). (5) Piping holdup in the full-scale coalescer system caused the pH to differ from the target value. Comparable hold-up in the facility could lead to less effective cleaning and precipitation of bayerite solid particles. (6) Based on analysis of the cleaning solutions from the full-scale test, the 'dirt capacity' of a 40 inch coalescer for these NAS solids was calculated to be 40-170 grams

  20. Fatal methemoglobinemia caused by liniment solutions containing sodium nitrite.

    Science.gov (United States)

    Saito, T; Takeichi, S; Yukawa, N; Osawa, M

    1996-01-01

    We describe a case of fatal methemoglobinemia (MetHb-emia) resulting from application of liniment solution containing large quantities of sodium nitrite. As a remedial treatment of atopic dermatitis, the liniment solution was applied all over the boy's body. Autopsy findings showed no significant macroscopic or microscopic findings except blood tinted chocolate brown color and chronic atopic dermatitis over the whole surface of the body. Quantitation of the methemoglobin (MetHb) in the blood was performed using spectrophotometer; MetHb concentration of the blood was 76%. Ion chromatographic determination revealed a nitrite concentration of 1 mg/L in the serum. Such a liniment solution is not authorized by the Ministry of Public Welfare. PMID:8934720

  1. Interaction of praseodymium chloride with sodium decavanadate in aqueous solution

    International Nuclear Information System (INIS)

    Method of residual concentrations, measurement of electric conductivity and pH, differential thermal, X-ray phase and chemical analyses, infrared spectroscopy were used for investigation of praseodymium (3) chloride interaction with sodium decavanadate in aqueous solution. It was established that 25-aqueous praseodymium decavanadate Pr2V10O28 X 25H2O formed as the intermediate solid phase. Then it transformed to the stable solid phase - hexahydrate of acid praseodymium pyrovanadate PrHV2O7 X 6H2O. The prepared vanadates decomposed at ? 130-160 deg C with formation of praseodymium orthovanadate and vanadium (5) oxide

  2. Crevice Corrosion of 321 Stainless Steel in Sodium Chloride Solutions

    International Nuclear Information System (INIS)

    Electrochemical techniques have been applied to study the crevice corrosion behaviour of stabilized 321 stainless steel in both 0.5, 1 and 2 M sodium chloride solutions at 25 and 80 degree . This type of stainless steel enjoys a good corrosion resistance especially in the heat affected zone (Haz) of welds. In this investigation the crevice corrosion of 321 stainless steel was studied in both bulk solution environments as well as in chloride solutions simulating those formed inside crevices. A metal-to-nonmetal crevice assembly, in which disc type specimens were faced to a PTFE crevice former, is used for bulk solution tests. Crevice-free specimens of solutions formed inside crevices (known as the critical crevice solutions, CCS). Cyclic potentiodynamic technique was used in evaluating the electrochemical corrosion performance of the alloy in bulk (0.5 and 1 M Nacl) environment. This revealed that both chloride ion concentration and temperature have a marked effect on the electrochemical parameters generally used for the evaluation of the crevice corrosion susceptibility. This included the corrosion potential. E corr. The passivity breakdown potential, Eb, and the protection potential, E p

  3. Efeitos da correção da acidose metabólica com bicarbonato de sódio sobre o catabolismo protéico na insuficiência renal crônica / The effects of the correction of metabolic acidosis with sodium bicarbonate on protein catabolism in chronic kidney failure

    Scientific Electronic Library Online (English)

    Denise, MAFRA; Roberto Carlos, BURINI.

    2001-04-01

    Full Text Available A desnutrição protéico-energética constitui problema comum aos pacientes com insuficiência renal crônica, influenciando diretamente na sua morbi-mortalidade. A acidose metabólica tem papel no catabolismo protéico, ativando a via proteolítica proteasoma-ubiquitina, dependente de adenosina trifosfato, [...] e conjuntamente com glicocorticóides induz uma maior atividade na desidrogenase que degrada os aminoácidos de cadeia ramificada. Esta revisão teve como objetivo descrever o mecanismo pelo qual a acidose metabólica nos pacientes com insuficiência renal crônica promove o catabolismo protéico, favorecendo assim a desnutrição, bem como avaliar os efeitos do uso de bicarbonato de sódio na correção da acidose e conseqüentemente redução do catabolismo protéico. Pesquisas mostram melhora da acidose pelo uso de bicarbonato de sódio e conseqüente redução do catabolismo protéico na insuficiência renal crônica, podendo ser esta uma conduta promissora na atenuação da desnutrição nestes pacientes. Abstract in english Protein-Energy Malnutrition is common among patients with chronic kidney failure, thus increasing morbidity and mortality. Several studies have shown that metabolic acidosis is a major cause of muscle protein breakdown, and recently it was attributed to ATP-dependent ubiquitin-proteasome proteolytic [...] pathway. Acidosis, plus glucocorticoids, also respond to increasing branched-chain amino acids oxidation. In this review, the impact of metabolic acidosis on protein and amino acid metabolism is examined in order to understand its effect on lean body mass and the nutritional status of patients with chronic kidney failure. The study also observes whether or not sodium bicarbonate supplementation is beneficial to chronic kidney failure patients. In summary, there is a preliminary evidence suggesting that the correction of acidosis using sodium bicarbonate reduces protein degradation in chronic kidney failure patients, thus emerging as a potential therapy for reducing protein-energy malnutrition among them.

  4. Efeitos da correção da acidose metabólica com bicarbonato de sódio sobre o catabolismo protéico na insuficiência renal crônica The effects of the correction of metabolic acidosis with sodium bicarbonate on protein catabolism in chronic kidney failure

    Directory of Open Access Journals (Sweden)

    Denise MAFRA

    2001-04-01

    Full Text Available A desnutrição protéico-energética constitui problema comum aos pacientes com insuficiência renal crônica, influenciando diretamente na sua morbi-mortalidade. A acidose metabólica tem papel no catabolismo protéico, ativando a via proteolítica proteasoma-ubiquitina, dependente de adenosina trifosfato, e conjuntamente com glicocorticóides induz uma maior atividade na desidrogenase que degrada os aminoácidos de cadeia ramificada. Esta revisão teve como objetivo descrever o mecanismo pelo qual a acidose metabólica nos pacientes com insuficiência renal crônica promove o catabolismo protéico, favorecendo assim a desnutrição, bem como avaliar os efeitos do uso de bicarbonato de sódio na correção da acidose e conseqüentemente redução do catabolismo protéico. Pesquisas mostram melhora da acidose pelo uso de bicarbonato de sódio e conseqüente redução do catabolismo protéico na insuficiência renal crônica, podendo ser esta uma conduta promissora na atenuação da desnutrição nestes pacientes.Protein-Energy Malnutrition is common among patients with chronic kidney failure, thus increasing morbidity and mortality. Several studies have shown that metabolic acidosis is a major cause of muscle protein breakdown, and recently it was attributed to ATP-dependent ubiquitin-proteasome proteolytic pathway. Acidosis, plus glucocorticoids, also respond to increasing branched-chain amino acids oxidation. In this review, the impact of metabolic acidosis on protein and amino acid metabolism is examined in order to understand its effect on lean body mass and the nutritional status of patients with chronic kidney failure. The study also observes whether or not sodium bicarbonate supplementation is beneficial to chronic kidney failure patients. In summary, there is a preliminary evidence suggesting that the correction of acidosis using sodium bicarbonate reduces protein degradation in chronic kidney failure patients, thus emerging as a potential therapy for reducing protein-energy malnutrition among them.

  5. Photo-electrochemical analysis of passive film formed on X80 pipeline steel in bicarbonate/carbonate buffer solution

    International Nuclear Information System (INIS)

    Photo-electrochemical measurement was used to explore the formation potential, formation time, chloride ions concentration, applied potential and pH value of the solution on the electronic property of passive film formed on X80 pipeline steel in 1 M NaHCO3/0.5 M Na2CO3 buffer solution. The results showed that the photocurrent is positive, indicating an n-type semiconductor character of the passive film, the photocurrent increased with increasing the formation potential, prolonging the formation time, decreasing chloride ions concentration, rising applied potential and decreasing the pH value of the solution. Capacitance measurement exhibited a positive slope of Mott-Schottky plot, and the slopes of Mott-Schottky plots increased with the increasing formation potential, showing a decrement of the donor density of the passive film

  6. Anodic polarization behavior of low-carbon steel in concentrated sodium hydroxide and sodium nitrate solutions

    International Nuclear Information System (INIS)

    High-level radioactive wastes, primarily consisting of concentrated sodium hydroxide (NaOH) and sodium nitrate (NaNO3) solutions, are stored in large underground storage tanks made of low-carbon steel. The anodic polarization behavior of low-carbon steel in concentrated solutions of 10 M NaOH and various concentrations of NaNO3 (0.01-2.0 M) was determined in order to predict the caustic stress corrosion cracking (CSCC) susceptibility of the tanks. The active-passive transition peak exhibited during anodic polarization of low-carbon steel in 10 M NaOH, typically associated with CSCC, at -0.25 and -0.75 VSCE, is still present at the lower and higher concentrations of nitrate. However, there is a mid-range of nitrate concentrations (0.5-1 M) within which the peak is suppressed by the strongly oxidizing nitrate in the presence of oxygen, a cathodic depolarizer. Temperature also affects the magnitude of this mid-range of nitrate concentrations where CSCC is seen to be electrochemically prevented. The data suggest that the oxygen solubility at the relatively low temperatures tested (corr is driven more noble than the active-passive transition peak

  7. Visco-Elastic Properties of Sodium Hyaluronate Solutions

    Science.gov (United States)

    Kulicke, Werner-Michael; Meyer, Fabian; Bingöl, Ali Ö.; Lohmann, Derek

    2008-07-01

    Sodium Hyaluronate (NaHA) is a member of the glycosaminoglycans and is present in the human organism as part of the synovial fluid and the vitreous body. HA is mainly commercialized as sodium or potassium salt. It can be extracted from cockscombs or can be produced by bacterial fermentation ensuring a low protein content. Because of its natural origin and toxicological harmlessness, NaHA is used to a great extent for pharmaceutical and cosmetic products. In medical applications, NaHA is already being used as a component of flushing and stabilizing fluids in the treatment of eye cataract and as a surrogate for natural synovial fluid. Another growing domain in the commercial utilization of NaHA is the field of skin care products like dermal fillers or moisturizers. In this spectrum, NaHA is used in dilute over semidilute up to concentrated (0solutions. In order to optimize NaHA samples for their specific utilization and to find new applications, it is of great interest to understand its viscoelastic behavior. We therefore present in this contribution the results of a comprehensive investigation of the viscous and elastic material functions of different NaHA samples. This includes, besides shear flow and oscillatory experiments, the performance of rheo-optical measurements in order to determine the elastic component in the range of low shear rates and low concentrations.

  8. Radiolysis of sodium p-cumenesulfonate in aqueous solution

    International Nuclear Information System (INIS)

    The reactions of hydrated electron eaq?, hydrogen atom (H) and CO2? (reducing species) as well as Cl2?, Br2?, N3?, OH, O?, SO4? radicals (oxidizing species) with sodium p-cumenesulfonate (SCS) in aqueous solution below minimum hydrotrope concentration have been studied by the method of steady-state and pulse radiolysis. The spectra of transient intermediates, leading to the final products, are presented. The rate constants for the reduction or oxidation reaction of the SCS are also given. The fate of the primary products of the SCS reaction produced during the pulse radiolysis under reductive or oxidative conditions is discussed. - Highlights: ? We determined the minimum hydrotrope concentration (MHC) for SCS. ? We analyzed the SCS reactions with oxidizing and reducing species. ? The rate constants for the oxidation and reduction of SCS were given

  9. Kinetics of conversion of celestite to strontium carbonate in solutions containing carbonate, bicarbonate and ammonium ions and dissolved ammonia

    Directory of Open Access Journals (Sweden)

    Zoraga Mert

    2014-01-01

    Full Text Available Celestite concentrate (SrSO4 has been converted to SrCO3 in solutions containing CO32-, HCO3- and NH4+ ions and dissolved ammonia. The effects of stirring speed, CO32- ion concentration; temperature and particle size of SrSO4 on the reaction rate were investigated. It was found that the conversion of SrSO4 was increased by increasing the temperature and decreasing the particle size, while the reaction rate was decreased with increasing the CO32- ion concentration. However, there was no effect of the stirring speed on the reaction rate. The conversion reaction was under chemical reaction control and the Shrinking Core Model was suitable to explain the reaction kinetics. The activation energy for the conversion reaction was found to be 41.9 kJ mol-1. The amounts of the elements in the reaction solution were determined quantitatively by inductively coupled plasma-optical emission spectrometry. The characterization of the solid reactant and product was made using scanning electron microscopy-energy dispersive spectrometry and X-ray powder diffraction analytical techniques.

  10. Improving the Corrosion Inhibitive Strength of Sodium Sulphite in Hydrogen Cyanide Solution Using Sodium Benzoate

    Directory of Open Access Journals (Sweden)

    Muhammed Olawale Hakeem AMUDA

    2008-12-01

    Full Text Available The improvement in the inhibitive strength of sodium sulphite on corrosion of mild steel in hydrogen cyanide by adding sodium benzoate in regulated volume was investigated using the fundamental weight loss measurement.500 ppm concentration inhibitive mixtures of sodium benzoate and sodium sulphite in three different volume ratios (5/15, 10/10, 15/5 were formulated and studied for corrosion rate in 200ml hydrogen cyanide fluid. Result obtained indicates that the corrosion rate of mild steel in hydrogen cyanide in the presence of sodium benzoate/sodium sulphite inhibitive mixtures range 0.322mmpy to 1.1269mmpy across the three volumetric ratios considered. The 15ml5ml sodium benzoatesodium sulphite mixture had the best average corrosion rate of 0.5123mmpy.The corrosion rate followed reducing pattern after the first 200 hours of immersion. The average corrosion rate in the sodium benzoate / sodium sulphite mixture is less than the rate in sodium sulphite and the mixture is only effective after long time exposure.It is concluded that adding sodium benzoate to sodium sulphite in the volumetric ratio 155ml improves the inhibitive strength of sodium sulphite on the corrosion of mild steel in hydrogen cyanide environment.

  11. Sodium silicate solutions from dissolution of glasswastes. Statistical analysis

    Directory of Open Access Journals (Sweden)

    Torres-Carrasco, M.

    2014-05-01

    Full Text Available It has studied the solubility process of four different waste glasses (with different particle sizes, 125 µm in alkaline solutions (NaOH and NaOH/Na?CO? and water as a reference and under different conditions of solubility (at room temperature, at 80°C and a mechano-chemical process. Have established the optimal conditions of solubility and generation of sodium silicates solutions, and these were: the smaller particle size (Se ha estudiado el proceso de solubilidad de cuatro diferentes residuos vítreos (con distintas granulometrías, 125 µm en disoluciones alcalinas de NaOH y NaOH/Na?CO? y agua como medio de referencia y bajo distintas condiciones de solubilidad (a temperatura ambiente, a 80°C y con un proceso mecano-químico. Se han establecido las condiciones óptimas de solubilidad y generación de disoluciones de silicato sódico, y estas son: menor tamaño de partícula del residuo vítreo (inferior a 45 µm, con la disolución de NaOH/Na?CO? y tratamiento térmico a 80°C durante 6 horas de agitación. El análisis estadístico realizado a los resultados obtenidos da importancia a las variables estudiadas y a las interacciones de las mismas. A través de ²?Si RMN MAS se ha confirmado la formación, tras los procesos de disolución, de un silicato monomérico, apto para su utilización como activador en la preparación de cementos y hormigones alcalinos.

  12. Sodium sulfate as an eluant for concentrated solution of pertechnetate.

    Science.gov (United States)

    Mushtaq, A; Haider, I

    2008-08-01

    Fission molybdenum-99 based technetium-99m chromatography generators are the most widely employed generator systems in the field of diagnostic nuclear medicine. In the first week these generators provide high specific volume activity Na99mTcO4, but in the second week the radioactive concentration of the eluate (99mTc) becomes 17% of that at the beginning of the first week. Low specific volume activity limits the clinical procedures (e.g. 99mTc-DTPA for lung ventilation scanning, 99mTc-sestamibi for myocardial perfusion studies, 99mTc-ECD for brain imaging and 99mTc-red cells for testicles) that can be performed at the beginning of the second week. To overcome such limitations sodium sulfate was used as an eluant, which provides>80% of 99mTc radioactivity in 2 ml solution, while 0.9% NaCl provides only 40-45% 99mTc in first 2 ml solution. PMID:18280744

  13. Sodium sulfate as an eluant for concentrated solution of pertechnetate

    International Nuclear Information System (INIS)

    Fission molybdenum-99 based technetium-99m chromatography generators are the most widely employed generator systems in the field of diagnostic nuclear medicine. In the first week these generators provide high specific volume activity Na99mTcO4, but in the second week the radioactive concentration of the eluate (99mTc) becomes ?17% of that at the beginning of the first week. Low specific volume activity limits the clinical procedures (e.g. 99mTc-DTPA for lung ventilation scanning, 99mTc-sestamibi for myocardial perfusion studies, 99mTc-ECD for brain imaging and 99mTc-red cells for testicles) that can be performed at the beginning of the second week. To overcome such limitations sodium sulfate was used as an eluant, which provides >80% of 99mTc radioactivity in 2 ml solution, while 0.9% NaCl provides only 40-45% 99mTc in first 2 ml solution

  14. Gadolinium block of calcium channels: influence of bicarbonate.

    Science.gov (United States)

    Boland, L M; Brown, T A; Dingledine, R

    1991-11-01

    The selectivity of block of voltage-activated barium (Ba2+) currents by lanthanide ions was studied in a rat dorsal root ganglion (DRG) cell line (F11-B9), rat and frog peripheral neurons, and rat cardiac myocytes using the whole-cell patch clamp technique. Gadolinium (Gd3+) produced a dose-dependent and complete inhibition of whole-cell Ba2+ current in all cells studied, including cells expressing identified dihydropyridine-sensitive L-type currents and omega-conotoxin-sensitive N-type currents. Like Gd3+, lutetium (Lu3+) and lanthanum (La3+) blocked all Ba2+ current with little selectivity for different components of the whole-cell current. Gd3+ block of Ba2+ currents was incomplete, however, when sodium bicarbonate (5-22.6 mM) was added to the standard HEPES-buffered external Ba2+ solution. In rat DRG neurons and F11-B9 cells, a fraction of the whole-cell Ba2+ current recorded in the presence of bicarbonate was resistant to block by saturating concentrations of Gd3+ (50-100 microM). The resistant current inactivated more rapidly than the original current giving the appearance that, under these conditions, Gd3+ block is more selective for the slowly inactivating component of the whole-cell current. Bicarbonate modification of Gd3+ block occurred both before and after omega-conotoxin block of N-type currents in rat DRG neurons, suggesting that even in the presence of bicarbonate, Gd3+ block was not selective for N-type currents. PMID:1786527

  15. Improving the Corrosion Inhibitive Strength of Sodium Sulphite in Hydrogen Cyanide Solution Using Sodium Benzoate

    OpenAIRE

    Muhammed Olawale Hakeem AMUDA; Olusegun Olusoji SOREMEKUN; Olakunle Wasiu SUBAIR; Atinuke OLADOYE

    2008-01-01

    The improvement in the inhibitive strength of sodium sulphite on corrosion of mild steel in hydrogen cyanide by adding sodium benzoate in regulated volume was investigated using the fundamental weight loss measurement.500 ppm concentration inhibitive mixtures of sodium benzoate and sodium sulphite in three different volume ratios (5/15, 10/10, 15/5) were formulated and studied for corrosion rate in 200ml hydrogen cyanide fluid. Result obtained indicates that the corrosion rate of mild steel i...

  16. Use of hypertonic solutions of sodium chloride in hypergranulating wounds

    Directory of Open Access Journals (Sweden)

    Bruno de Assis Quelemente, Ana Beatriz Pinto da Silva Morita, Angelo Teixeira Balbi

    2009-04-01

    Full Text Available Objective: to verify the efficiency of hypertonic solution (NaCl/20% on the hypergranulation due to the constant hypergranulating wound beds treated in venous ulcers in the daily clinic practice, which delays and disables cells epithelization. Methodology: clinical case study, performed in an outpatient’s clinic of Médio Vale do Paraíba, from February to March 2008. MCT, 60 years old, female, white skin, systematic arterial hypertension controlled, with wounds on the middle part and region of distal third of the left leg. Dressings were made with prior sterilization sores of sodium chloride to 0.9%, which was applied compress of gauze soaked with hypertonic solution (NaCl 20% was applied on the region presenting hypergrantulation tissue and immediately occluded with dry gauze and fixed with crepe bandage and adhesive tapes. Results: on February 13, 2008, the first wound on the middle part of the left leg measured 3,5 x 2,3 inches (9x6 cm and 2,7 9 inches (7 cm of hypergranulation, and the second wound on the region of distal third of the left leg measured 5,5 x 5,1 inches (14x13 cm and 5,1 inches (13 cm of hypergranulation. After 22 days, the first wound measured 1,5 x 1,5 inches (4X4 cm and 1,5 inches (4 cm of hypergranulation and the second wound measured 4,3 x 3,9 inches (11X10 cm and 2,3 inches (6 cm of hypergranulation. Conclusion: the healing process presented a satisfactory evolution after applying hypertonic solution (NaCl/20% improving the characteristic of the wound bed and diminishing the area where hypergranulation was present.

  17. Clinical Effect of a Mixed Solution of Sodium Hyaluronate and Sodium Carboxymethylcellulose During the Transconjunctival Approach for Orbital Wall Reconstruction

    OpenAIRE

    Kang, Byung Wan; Lee, Hyo Seok; Oh, Han Jin; Yoon, Kyung Chul

    2012-01-01

    This study aimed to evaluate the anti-adhesive effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC, Guardix-sol®) during the transconjunctival approach to orbital wall reconstruction. Eighty-seven patients who underwent orbital wall reconstruction by the transconjunctival approach were enrolled in this prospective study. We applied HACMC between the orbicularis oculi muscle and the orbital septum after surgery in 47 patients and did not use it in 40 patie...

  18. 21 CFR 520.563 - Diatrizoate meglumine and diatrizoate sodium oral solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diatrizoate meglumine and diatrizoate sodium oral... § 520.563 Diatrizoate meglumine and diatrizoate sodium oral solution. (a) Specifications. Diatrizoate meglumine oral solution is a water soluble radiopaque medium containing 66 percent diatrizoate meglumine...

  19. Componentry, constructive and process solutions of sodium vapour precipitation problem

    International Nuclear Information System (INIS)

    Sodium vapour trap for periodic operation (SVT) is installed to present of sodium vapour emissions after response of safety valve on tanks with sodium and to provide protection from sodium vapour during planned argon blowing from tanks. It is recommended that SVT be placed directly above tanks with sodium. But the main problem of BN-600 and BN-800 componentry (grouping) is the lack of premises. So, the recommended placement is impossible. The principal scheme of SVT piping BN-800. Argon purification from sodium vapor is carried out by air refrigerating. Refrigerating degree is regulated by control valve on the air delivery pipe to SVT. There is montejus tank in the scheme of SVT piping for liquid sodium drainage that is condensed in SVT. Sodium drainage pipe is combined with argon delivery pipe (line E). There are two main problems with the present construction of SVT based on operation experience of BN-600: 1. The horizontal pipeline 'Ar+Na' before the SVT entrance is a dangerous section of this piping. Electric heating of this pipeline is always 'on'. Inspite of this, sodium vapour condenses before SVT. It means that the pipeline becomes progressively clogged up. 2. Two substances (argon with sodium vapour and liquid sodium) are moving towards each other in one pipeline (line E). This is the most probable place of clogging by sodium, especially branch-pipe in the connection point of line E with SVT. Sodium cruds turn into solid state in the process of argon delivery pipe clogging.In most cases solid scrubs melting temperature exceeds 400-500C depending on chemical composition of crud (for example caustic soda - 1200C). It means that it is almost impossible to heat the pipeline to restore its passability. The only measure in this case is the change of pipe section during BN stop. The first problem can be solved by: - Increasing the diameter (which was DN40 in the project of BN-600, and is DN80 in BN-800); - Increasing the temperature of electric heating; - Minimizing pipeline lengths; The second problem can only be solved by changing SVT design: The principal scheme of SVT piping that is optimal in the lack of premises. Argon delivery pipeline is separated from sodium drainage pipeline. Drainage clogging is less probable in such SVT design

  20. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to carbonate and bicarbonate salts of sodium and potassium and maintenance of normal bone (ID 331, 1402) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    2011-01-01

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of health claims in relation to carbonate and bicarbonate salts of sodium and potassium and maintenance of normal bone. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from stakeholders. The food constituents that are the subject of the health claim are carbonate and bicarbonate salts of sodium and potassium. The Panel considers that carbonate and bicarbonate salts of sodium and potassium are sufficiently characterised. The claimed effects are “acid/base balance and bone health” and “bone density/bone health”. The target population is assumed to be the general population.In the context of the proposed wordings, the Panel assumes that the claimed effects refer to the maintenance of normal bone by maintaining acid-base balance. The Panel considers that maintenance of normal bone is a beneficial physiological effect. No references were provided from which conclusions could be drawn for the scientific substantiation of the claim. On the basis of the data presented, the Panel concludes that a cause and effect relationship has not been established between the dietary intake of carbonate or bicarbonate salts of sodium or potassium and maintenance of normal bone.

  1. [Functioning biological activity of mean mineralized sodium bicarbonate in water from the "Pitoniakówka" source in Szczawnica, designed for health resort potable cures].

    Science.gov (United States)

    Drobnik, M; Latour, T

    2001-01-01

    In the experiments on animals the biological activity of the water from its intake "Pitoniakówka" (outflow B + C + D + G) in Szczawnica has been determined. The basic investigations were carried out on rats whom in the course of 24 days the investigated water was being administered to drink ad libitum or by probe in a single daily dose of 10.7 ml/kg of body weight. It has been ascertained that the water caused a statistically significant increase of the concentration of sodium and a fall of the levels of potassium, magnesium, calcium, total cholesterol, the HDL fraction of cholesterol, total lipids in the blood serum, also of hematocrit, hemoglobin and erythrocytes. The investigated water inhibited the motor activity of the small intestine of the rabbit, caused increased urination and increased water turnover in the organism. A long-lasting application of the investigated water may lead to the genesis of metabolic acidosis. There was not observed any cholagonic and any chologenic activity of the investigated water in guinea pigs or any effect of that water on the elements of the carbohydrate metabolism, the protein metabolism or on the peripheral blood smear in rats. PMID:11452742

  2. Experimental study of concentrated solutions containing sodium and chloride pollutants in SG flow restricted areas

    Energy Technology Data Exchange (ETDEWEB)

    You, D.; Lefefre, S.; Feron, D. [CEA-Saclay, Lab. d' Etude de la Corrosion Aqueuse, Gif-sur-Yvette (France); Vaillant, F. [EDF-Les Renardieres - DRD/EMA, Moret-sur-Loing (France)

    2002-07-01

    In steam generators, the hideout processes occur in flow restricted areas. Non volatile pollutants, i.e. species less soluble in the vapour phase than in the liquid water phase, accumulate such as sodium hydroxide or sodium chloride. The thermodynamic equilibrium between these two phases is described in terms of liquid-vapour equilibrium constants for soluble species and boiling constant for the solvent. The presented experimental investigation has been realised with the EVA device: the boiling pressure evolution has been measured during the hideout process of sodium hydroxide and sodium chloride aqueous solutions. The results clearly demonstrated that high sodium hydroxide aqueous solutions are thermodynamically possible while with sodium chloride, it seems that precipitation occurs before. (authors)

  3. Experimental study of concentrated solutions containing sodium and chloride pollutants in SG flow restricted areas

    International Nuclear Information System (INIS)

    In steam generators, the hideout processes occur in flow restricted areas. Non volatile pollutants, i.e. species less soluble in the vapour phase than in the liquid water phase, accumulate such as sodium hydroxide or sodium chloride. The thermodynamic equilibrium between these two phases is described in terms of liquid-vapour equilibrium constants for soluble species and boiling constant for the solvent. The presented experimental investigation has been realised with the EVA device: the boiling pressure evolution has been measured during the hideout process of sodium hydroxide and sodium chloride aqueous solutions. The results clearly demonstrated that high sodium hydroxide aqueous solutions are thermodynamically possible while with sodium chloride, it seems that precipitation occurs before. (authors)

  4. Lack of promotion of urinary bladder carcinogenesis by sodium bicarbonate and/or L-ascorbic acid in male ODS/Shi-od/od rats synthesizing alpha 2 mu-globulin but not L-ascorbic acid.

    Science.gov (United States)

    Mori, S; Murai, T; Hosono, M; Machino, S; Makino, S; Chou, C; Fukushima, S

    1997-08-01

    The study was designed to investigate whether sodium bicarbonate (NaHCO3) and/or L-ascorbic acid (AsA) promote urinary bladder carcinogenesis in male ODS/Shi-od/od (ODS) rats, which, unlike male F344 rats, are resistant to sodium L-ascorbate (Na-AsA)-promoting effects. Whereas F344 rats can synthesize AsA and alpha 2 mu-globulin (A2 mu-G), only A2 mu-G in produced in ODS rats. The two strains were given 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in their drinking water for 2 wk and then were fed basal CA-1 diet supplemented with 3% NaHCO3 plus 5% AsA (NaHCO3 + AsA), 3% NaHCO3, 5% AsA, or no chemicals for 32 wk. ODS rats given BBN-NaHCO3 or BBN-(NaHCO3 + AsA) had only a few small carcinomas in the urinary bladder, like those receiving BBN alone or BBN-AsA. In contrast, F344 rats administered BBN-NaHCO3 or BBN-(NaHCO3 + AsA) had many more, larger, carcinoma than animals of the same strain given BBN alone or BBN-AsA. AsA alone did not have any effect in either strain. Administration of NaHCO3 alone or NaHCO3 + AsA was associated with significant elevation of urinary pH and Na+ concentration to the same extent in both strains but, again, AsA alone was without effect. NaHCO3 + AsA and AsA alone increased the urinary concentration of total ascorbic acid in both strains but the observed levels wer lower in ODS rats. The results indicate that ODS rats are resistant to the modifying effects of NaHCO3 and/or AsA on two-stage urinary bladder carcinogenesis, and thus that the susceptibility to the promotional activity of sodium-salt-type compounds may be regulated by factors other than A2 mu-G-synthesizing ability and urinary levels of pH, Na+ and total ascorbic acid. PMID:9350223

  5. Myocardial uptake of thallium-201 augmented with bicarbonate: concise communication

    International Nuclear Information System (INIS)

    Sodium bicarbonate was used to enhance the myocardial concentration of Tl-201 in rabbits and dogs. Organ distribution studies in rabbits and in vivo imaging in dogs showed a 1.5 to 2-fold increase in myocardial Tl-201 concentration in bicarbonate-treated animals as compared with matched controls. Image improvement was noted, with threefold enhancement of myocardium-to-liver ratios. The results suggest that a similar improvement may be possible for clinical myocardial imaging

  6. Randomized controlled trial of sodium phosphate tablets vs polyethylene glycol solution for colonoscopy bowel cleansing

    OpenAIRE

    Jung, Yoon Suk; Lee, Chang Kyun; Kim, Hyo Jong; Eun, Chang Soo; Han, Dong Soo; Park, Dong Il

    2014-01-01

    AIM: To compare efficacy, patient compliance, acceptability, satisfaction, safety, and adenoma detection rate of sodium phosphate tablets (NaP, CLICOLONTM) to a standard 4 L polyethylene glycol (PEG) solution for bowel cleansing for adults undergoing colonoscopy.

  7. Sorption of cadmium from solutions of hydrochloric acid and sodium chloride with ionites

    International Nuclear Information System (INIS)

    Sorption of cadmium on ionites KU-2x8 and AV-17x8 from 0.001-5.0 N of hydrochloric acid solutions was investigated. Complexing of cadmium was demonstrated. The isoelectric point was obtained during sorption of cadmium from hydrochloric acid solutions. Complexing of cadmium from 0.1-5.0 N sodium chloride solutions was established

  8. Does bicarbonated mineral water rich in sodium change insulin sensitivity of postmenopausal women? / ¿Modifica el agua mineral bicarbonatada rica en sodio la sensibilidad a la insulina de las mujeres postmenopáusicas?

    Scientific Electronic Library Online (English)

    S., Schoppen; F. J., Sánchez-Muniz; A. M.ª, Pérez-Granados; J. A., Gómez-Gerique; B., Sarriá; S., Navas-Carretero; M.ª Pilar, Vaquero.

    2007-10-01

    Full Text Available Objetivo: Estudiar los efectos de la ingesta de 0.5L de dos aguas minerales bicarbonatadas ricas en sodio (BMW-1 y 2), junto con una comida estándar, sobre los cambios en la insulina y la glucosa postprandial; y determinar si los posibles efectos varían en función de la resistencia a la insulina eva [...] luada a través del modelo homeostático (HOMA). Métodos: 18 mujeres postmenopáusicas sanas participaron en un estudio triple cruzado aleatorizado, en el que bebieron 2 aguas minerales bicarbonatadas ricas en sodio (BMW-1 y 2) y un agua mineral débil (LMW) junto con una comida estándar rica en grasa. Se tomaron muestras de sangre en ayunas y postprandiales a los 30, 60 y 120 min. Se determinó glucosa, insulina, colesterol y triglicéridos en suero. La resistencia a la insulina fue estimada a través del HOMA y la sensibilidad a la insulina se calculó mediante el índice de sensibilidad cuantitativa a la insulina (QUICKY). Resultados: Los niveles de glucosa no presentaron cambios. Los valores de HOMA y QUICKY presentaron una fuerte correlación inversa (r = -1,000; p Abstract in english Aim: To study the effects of drinking 0.5 L of two sodium-rich bicarbonated mineral waters (BMW-1 and 2), with a standard meal, on postprandial insulin and glucose changes. And to determine, if the effects vary depending on insulin resistance, measured by homeostasis model assessment (HOMA). Methods [...] : In a 3-way randomized crossover study, 18 healthy postmenopausal women consumed two sodiumrich BMWs and a low-mineral water (LMW) with a standard fat-rich meal. Fasting and postprandial blood samples were taken at 30, 60 and 120 min. Serum glucose, insulin, cholesterol and triacylglycerols were determined. Insulin resistance was estimated by HOMA and insulin sensitivity was calculated by quantitative insulin sensitivity check index (QUICKY). Results: Glucose levels did not change. HOMA and QUICKY values were highly inversely correlated (r = -1,000; p

  9. Avaliação de procedimentos de extração dos óxidos de ferro pedogênicos com ditionito-citrato-bicarbonato de sódio / Evaluation of pedogenic iron oxide extraction procedures with sodium dithionite-citrate-bicarbonate

    Scientific Electronic Library Online (English)

    A. V., Inda Junior; N., Kämpf.

    2003-12-01

    Full Text Available Em 20 amostras hematíticas e goethíticas de horizontes B latossólicos, uma de B plíntico, uma de B incipiente e uma de saprolito, foram avaliados dois procedimentos de extração de óxidos de ferro pedogênicos (Fe d) por ditionito-citrato-bicarbonato de sódio (DCB). O procedimento a 80 ºC (DCB80) extr [...] aiu aproximadamente 90 % do Fe d na primeira extração e praticamente a totalidade do mesmo na segunda extração, sendo mais efetivo que o procedimento a temperatura ambiente (DCB20), o qual teve sua eficiência reduzida com o aumento da substituição isomórfica de Fe3+ por Al3+ na goethita. A substituição isomórfica de Fe3+ por Al3+ na goethita determinada por DCB80 superestimou os valores determinados por DRX conforme aumentaram as extrações. Em amostras hematíticas, esta estimativa foi prejudicada pela presença de maghemita que dissolveu juntamente com a hematita. Abstract in english Pedogenic iron oxides (Fe d) were quantified in 22 hematitic and goethitic soil samples (19 from oxic horizons; one from a plinthic horizon; one from a cambic horizon; one from saprolite) by use of two extraction procedures with sodium dithionite-citrate-bicarbonate (DCB). Approximately ninety perce [...] nt of the Fe d content was extracted at the first extraction by the DCB80 procedure. This procedure was more effective at extracting Fe d than the DCB20, whose efficiency decreased with increasing Al3+-substitution in goethite. Compared with the DRX analysis, Al3+-substitution in goethite determined by the DCB80 procedure was superestimated. Maghemite masked Al3+-substitution estimates in hematite from hematitic samples.

  10. Thermodynamic properties of aqueous solutions of sodium ibuprofen at 293.15-318.15 K

    Science.gov (United States)

    Manin, N. G.; Perlovich, G. L.

    2015-04-01

    The enthalpies of solution and dilution of aqueous solutions of sodium ibuprofen (NaIBP) with concentrations of m F1 Phoenix differential scanning calorimeter (NETZSCH, Germany). The virial coefficients of the enthalpies of aqueous solutions of NaIBP are derived in terms of the Pitzer model, and the thermodynamic properties of both the solutions and the solution components are calculated over the range of compound solubility. The variation in these characteristics as a function of concentration and temperature is analyzed.

  11. Effect of peroxodisulfate on uranium leaching with ammonium bicarbonate

    OpenAIRE

    Nurbek Nurpeisov; Yuliya Marchuk; B. Satybaldiyev; Bolat Uralbekov; Mukhambetkali Burkitbayev

    2013-01-01

    In this study, uranium leaching from ore material using acid solution and bicarbonate in a presence peroxodisulfate ion was examined. For experiments two different tips of leaching methods were used: leaching in static and dynamic conditions. The determination of uranium concentrations in product solutions were analyzed by titrimetric (by ammonia vanadate solution) method. The maximum yield of uranium leached with ammonium bicarbonate in a presence of ammonium peroxodisulfate (5 g/L) was only...

  12. Corrosion behavior of sodium-exposed stainless steels in chloride-containing aqueous solutions

    International Nuclear Information System (INIS)

    The corrosion behavior of sodium-exposed stainless steels in chloride-containing aqueous solutions was investigated. Results showed that sodium-corroded Type 316 stainless steel (prototypic Liquid Metal Fast Breeder Reactor (LMFBR) fuel cladding) maintains its integrity after five months exposure in these solutions at 820C and with chloride content up to 500 ppM. In contrast, sensitized and sodium mass transfer deposit-containing Type 304 stainless steel failed in the high chloride solution (500 ppM) within ten days at the same temperature. The failure was initiated by pitting and subsequently accelerated by intergranular attack. The results also show that high pH tends to reduce the susceptibility to failure while procedures commonly used for sodium removal have no significant effect on the water corrosion behavior of the test material. Based on the current results, it is concluded that water shortage is feasible for spent fuels in a LMFBR reprocessing plant

  13. Radiation protection by ascorbic acid in sodium alginate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Aliste, A.J.; Mastro, N.L. Del [Center of Radiation Technology, IPEN/CNEN/SP, University City, 05508-000 Sao Paulo (Brazil)]. E-mail: ajaliste@ipen.br

    2004-07-01

    Alginates are gelling hydrocolloids extracted from brown seaweed used widely in the nourishing and pharmaceutical industries. As alginic acid gellification retard food entrance in the stomach alginate is an additive used in diets. The objective of this work was to study the protective action of the ascorbic acid in alginate solutions against the action of {sup 60} Co gamma radiation. One % (w/v) solutions of alginate had been used and concentrations of ascorbic acid varied from 0 to 2.5% (w/v). The solutions were irradiated with doses up to 10 kGy. Viscosity/dose relationship and the p H of the solutions at 25 Centigrade were determined. Ascorbic acid behaved as an antioxidant against radiation oxidative shock in this model system of an irradiated viscous solution. Besides its radiation protective role on alginate solutions ascorbic acid promoted a viscosity increase in the range of concentrations employed. (Author)

  14. Bicarbonate sulfate exchange in canalicular rat liver plasma membrane vesicles

    International Nuclear Information System (INIS)

    The mechanism(s) and driving forces for biliary excretion of sulfate were investigated in canalicular rat liver plasma membrane vesicles (cLPM). Incubation of cLPM vesicles in the presence of an inside-to-outside (in, out) bicarbonate gradient but not pH or out-to-in sodium gradients, stimulated sulfate uptake 10-fold compared with the absence of bicarbonate and approximately 2-fold above sulfate equilibrium (overshoot). Initial rates of this bicarbonate gradient-driven [35S]-sulfate uptake were saturable with increasing concentrations of sulfate and could be inhibited by probenecid, N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate, acetazolamide, furosemide, 4-acetamideo-4'-isothiocyanostilbene-2,2'-disulfonic acid, and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (IC50, ?40 ?M). Cisinhibition of initial bicarbonate gradient-stimulated sulfate uptake and transstimulation of sulfate uptake in the absence of bicarbonate were observed with sulfate, thiosulfate, and oxalate but not with chloride, nitrate, phosphate, acetate, lactate, glutamate, aspartate, cholate, taurocholate, dehydrocholate, taurodehydrocholate, and reduced or oxidized glutathione. These findings indicate the presence of a sulfate (oxalate)-bicarbonate anion exchange system in canalicular rat liver plasma membranes. These findings support the concept that bicarbonate-sensitive transport system might play an important role in bile acid-independent canalicular bile formation

  15. Radiolysis of aqueous solutions of sodium thiosulfates. Chapter 9

    International Nuclear Information System (INIS)

    Radiation-chemical conversion of thiosulphate-ions was studied in 2.15x10-3 to 4x10-2 M Na2S2O3 in the presence of dissolved oxygen. The radiolysis product distribution carried out iodometrically, spectrophotometrically and complexometrically. The products of the thiosulphate ion radiolysis are sulphate, sulphite and sulphur. Study of the low-temperature radiolysis of sodium thiosulphate enables one to establish some of the initial products of the process, namely ion-radicals S2O3- and S2O2-, whose continued conversion leads to the formation of sulphur, sulphite and sulphate

  16. Thermophysical properties of sodium nitrate and sodium chloride solutions and their effects on fluid flow in unsaturated media

    International Nuclear Information System (INIS)

    Understanding movement of saline sodium nitrate (NaNO3) waste solutions is important for assessing the contaminant migration near leaking waste storage tanks in the unsaturated zone at the Hanford site (Washington, USA). The purpose of this study is to contribute a basic understanding of effects of the thermophysical behavior of NaNO3 solutions on fluid flow in unsaturated media. We first present mathematical expressions for the dependence of density, viscosity, solubility and vapor pressure of NaNO3 solutions on both salt concentration and temperature, which were determined by fitting from published measured data. Because the previous studies of thermophysical behavior of sodium chloride (NaCl) solutions can provide a basis for those of NaNO3 solutions, we also present a comparison of thermophysical properties of both salt solutions. We have implemented the functional thermophysical properties of NaNO3 solutions into a new TOUGH2 equation-of-state module EWASG-NaNO3, which is modified from a previous TOUGH2 equation-of-state module EWASG for NaCl. Using the simulation tool, we have investigated effects of the thermophysical properties on fluid flow in unsaturated media. The effect of density and viscosity of saline solutions has been long recognized. Here we focus our attention on the effect of vapor pressure lowering due to salinity. We present simulations of a one-dimensional problem to study this salinity-driven fluid flow. A number of simulations were performed using different values of thermal conductivity, permeability, and temperature, to illustrate conditions and parameters controlling these processes. Results indicate that heat conduction plays a very important role in this salinity-driven vapor diffusion by maintaining a nearly constant temperature. The smaller the permeability, the more water is transferred into the saline environment. Effects of permeability on water flow are also complicated by effects of capillary pressure and tortuosity. The higher the temperature, the more significant the salinity driven fluid flow

  17. Influence of hydroxypropylmethyl cellulose-sodium laurylsulfate interaction on rheological properties of the solution

    OpenAIRE

    Šaleti? Jelena V.; Sovilj Verica J.; Petrovi? Lidija B.

    2004-01-01

    Interactions between the polymers and surfactants in solution have widely been investigated because of their scientific and technological importance. These interactions can be utilized to modify the physicochemical properties of system in many food products, pharmaceutical formulations, personal care products, paints, pesticides, etc. Interaction between nonionic polymer - hydroxypropylmethyl cellulose (HPMC) and anionic surfactant - sodium laurylsulfate (SDS) in solution has been investigate...

  18. Critical role of bicarbonate and bicarbonate transporters in cardiac function.

    Science.gov (United States)

    Wang, Hong-Sheng; Chen, Yamei; Vairamani, Kanimozhi; Shull, Gary E

    2014-08-26

    Bicarbonate is one of the major anions in mammalian tissues and extracellular fluids. Along with accompanying H(+), HCO3 (-) is generated from CO2 and H2O, either spontaneously or via the catalytic activity of carbonic anhydrase. It serves as a component of the major buffer system, thereby playing a critical role in pH homeostasis. Bicarbonate can also be utilized by a variety of ion transporters, often working in coupled systems, to transport other ions and organic substrates across cell membranes. The functions of HCO3 (-) and HCO3 (-)-transporters in epithelial tissues have been studied extensively, but their functions in heart are less well understood. Here we review studies of the identities and physiological functions of Cl(-)/HCO3 (-) exchangers and Na(+)/HCO3 (-) cotransporters of the SLC4A and SLC26A families in heart. We also present RNA Seq analysis of their cardiac mRNA expression levels. These studies indicate that slc4a3 (AE3) is the major Cl(-)/HCO3 (-) exchanger and plays a protective role in heart failure, and that Slc4a4 (NBCe1) is the major Na(+)/HCO3 (-) cotransporter and affects action potential duration. In addition, previous studies show that HCO3 (-) has a positive inotropic effect in the perfused heart that is largely independent of effects on intracellular Ca(2+). The importance of HCO3 (-) in the regulation of contractility is supported by experiments showing that isolated cardiomyocytes exhibit sharply enhanced contractility, with no change in Ca(2+) transients, when switched from Hepes-buffered to HCO3 (-)- buffered solutions. These studies demonstrate that HCO3 (-) and HCO3 (-)-handling proteins play important roles in the regulation of cardiac function. PMID:25225601

  19. Relevance of rheological properties of sodium alginate in solution to calcium alginate gel properties.

    Science.gov (United States)

    Fu, Shao; Thacker, Ankur; Sperger, Diana M; Boni, Riccardo L; Buckner, Ira S; Velankar, Sachin; Munson, Eric J; Block, Lawrence H

    2011-06-01

    The purpose of this study is to determine whether sodium alginate solutions' rheological parameters are meaningful relative to sodium alginate's use in the formulation of calcium alginate gels. Calcium alginate gels were prepared from six different grades of sodium alginate (FMC Biopolymer), one of which was available in ten batches. Cylindrical gel samples were prepared from each of the gels and subjected to compression to fracture on an Instron Universal Testing Machine, equipped with a 1-kN load cell, at a cross-head speed of 120 mm/min. Among the grades with similar % G, (grades 1, 3, and 4), there is a significant correlation between deformation work (L(E)) and apparent viscosity (?(app)). However, the results for the partial correlation analysis for all six grades of sodium alginate show that L(E) is significantly correlated with % G, but not with the rheological properties of the sodium alginate solutions. Studies of the ten batches of one grade of sodium alginate show that ?(app) of their solutions did not correlate with L(E) while tan ? was significantly, but minimally, correlated to L(E). These results suggest that other factors--polydispersity and the randomness of guluronic acid sequencing--are likely to influence the mechanical properties of the resultant gels. In summary, the rheological properties of solutions for different grades of sodium alginate are not indicative of the resultant gel properties. Inter-batch differences in the rheological behavior for one specific grade of sodium alginate were insufficient to predict the corresponding calcium alginate gel's mechanical properties. PMID:21437788

  20. Study on the utilization of a sodium-sulfuric acid solution for the uranium minerals' leaching

    International Nuclear Information System (INIS)

    Argentine uranium minerals have been leached at bench scale with a different agent trying to reduce sulfuric acid consumption. The leaching agent was a sodium sulfate-sulfuric acid solution and the ore was from Sierra Pintada (San Rafael - Mendoza). The work was performed in stirred vessel at atmospheric pressure. The influence of different variables, pH, temperature, oxidant agent, sodium sulfate concentration and time, in the sulfuric acid consumption and the uranium yield was studied. (Author)

  1. Dynamics of boric acid sorption from sodium chloride solution by SB-1 anion exchanger

    International Nuclear Information System (INIS)

    Study on boron sorption from sodium chloride saturated solutions under dynamic conditions by SB-1 anion exchanger is carried out. Impact of the flow rate, contact time and sodium chloride background on the sorption output curve is studied. The process limiting stage is determined. Diffusion efficient coefficients are calculated. It is shown that process rate is limited by internal diffusion brake actions. 4 refs., 4 figs

  2. Corrosion Cyclic Voltammetry of Two Types of Heat-Affected Zones (HAZs) of API-X100 Steel in Bicarbonate Solutions

    Science.gov (United States)

    Eliyan, Faysal Fayez; Alfantazi, Akram

    2014-12-01

    This paper examined the electrochemical corrosion behavior and corrosion products of two types of heat-affected HAZs made from API-X100 steel. Cyclic voltammetry, with different scan rates and potential ranges at 10 cycles, was applied to analyze the interdependent corrosion reactions of cathodic reduction, anodic dissolution, passivation, and transpassivation. The HAZ cooled at 60 K/s, from a peak temperature of 1470 K (1197 °C) that was held for 15 seconds, exhibited better passivation and lower cathodic activity than the HAZ cooled at 10 K/s. Increasing bicarbonate concentration, from 0.05 and 0.2 to 0.6 M, increases the anodic activity and cathodic reduction, but accordingly protects the active surfaces and enhances passivation.

  3. Effect of different molarities of Sodium Hydroxide solution on the Strength of Geopolymer concrete

    Directory of Open Access Journals (Sweden)

    Shivaji S. Bidwe

    2015-03-01

    Full Text Available This paper contains the experimental study of strength of geopolymer concrete for different molarities of sodium hydroxide solution. This paper also contains results of the laboratory tests conducted to find out the effect of sodium hydroxide concentration on the strength of the geopolymer concrete. In these days the world is facing a major problem i.e. the environmental pollution. We can use fly ash instead of cement in the construction in order to reduce environmental pollution. The Concrete made by using Fly ash and alkaline liquid mixture as a binder is known as geopolymer concrete. In this study for the polymerization process alkaline liquids used are Sodium Hydroxide (NaOH and Sodium Silicate (Na2SiO3. Different molarities of sodium hydroxide solution i.e. 8M, 10M and 12M are taken to prepare different mixes and the compressive strength is calculated for each of the mix. The size of the cube specimens taken are 150mm X 150mm X 150mm. Curing of these cubes is done in an oven for 3 days and 28 days. The Compressive strength of these geopolymer concrete specimens is tested at 3 days and 28 days. The results show that there is increase in comp. strength of geopolymer concrete with increase in molarity of Sodium Hydroxide Solution. Ordinary Concrete Specimens are also manufactured with cement as binder. It is found that the Compressive strength of Geopolymer Concrete specimens is higher than the Compressive strength of Ordinary Concrete Specimens.

  4. Solute rejection by porous glass membranes. I - Hyperfiltration of sodium chloride and urea feed solutions.

    Science.gov (United States)

    Ballou, E. V.; Wydeven, T.; Leban, M. I.

    1971-01-01

    Hyperfiltration of sodium chloride and urea was studied with porous glass membranes in closed-end capillary form, to determine the effect of pressure, temperature, and concentration variations, and lifetime rejection and flux characteristics. Rejection data for sodium chloride were consistent with the functioning of the porous glass as a low-capacity ion-exchange membrane.

  5. Distal renal tubular acidosis in infancy: a bicarbonate wasting state.

    Science.gov (United States)

    Rodriguez-Soriano, J; Vallo, A; Garcia-Fuentes, M

    1975-04-01

    Three unrelated infants with apparently distal RTA were investigated. Growth retardation, polyuria, nephrocalcinosis, inappropriately high urinary pH, and marked dependence of bicarbonate excretion on urinary flow were characteristic of the distal or classic form of RTA, but the urinary loss of bicarbonate at normal serum values exceeded that usually found in children or adults with this disorder. Renal tubular function was studied during hypotonic saline diuresis in the three patients and in seven healthy control infants of similar age. Fractional delivery of sodium to the distal nephron was significantly higher in the patients than in control subjects. Sodium transport at the diluting segment was not impaired. The results support the assumption that the bicarbonate wasting was the consequence of an increased delivery of this substance to an already impaired distal nephron and thus further inhibited the distal mechanisms of net acid excretion. PMID:236365

  6. Electric field effects on alanine tripeptide in sodium halide solutions.

    Science.gov (United States)

    Astrakas, Loukas G; Gousias, Christos; Tzaphlidou, Margaret

    2015-12-01

    The electric field effects on conformational properties of trialanine in different halide solutions were explored with long-scale molecular dynamics simulations. NaF, NaCl, NaBr and NaI solutions of low (0.2?M) and high (2?M) concentrations were exposed to a constant electric field of 1000?V/m. Generally, the electric field does not disturb trialanine's structure. Large structural changes appear only in the case of the supersaturated 2.0?M NaF solution containing NaF crystals. Although the electric field affects in a complex way, all the ions-water-peptide interactions, it predominantly affects the electroselectivity effect, which describes specific interactions such as the ion-pair formation. PMID:25006865

  7. Radiolysis of sodium nitrate concentrated solutions in D2O

    International Nuclear Information System (INIS)

    The findings of a comparative analysis of NaNO3 concentrated solution radiolysis in D2O under exposure to gamma-rays of 60Co and 14.1 MeV fast neutrons are presented. As in case of H2O-basis solutions, NO2- yield depends insignificantly on the type of radiation as regards to the mechanism of indirect action. At the same time, as to the mechanism of direct action, the yield is 2 times as much the corresponding value of gamma radiolysis in case of neutron radiation. The constant of the rate of solvated electron reaction with NO3- ion in D2O is measured by the method of pulse radiolysis. The established value is 2 times lower than the similar value for the solutions in light water

  8. Viscometric study of chitosan solutions in acetic acid/sodium acetate and acetic acid/sodium chloride.

    Science.gov (United States)

    Costa, Cristiane N; Teixeira, Viviane G; Delpech, Marcia C; Souza, Josefa Virginia S; Costa, Marcos A S

    2015-11-20

    A viscometric study was carried out at 25°C to assess the physical-chemical behavior in solution and the mean viscometric molar mass (M¯v) of chitosan solutions with different deacetylation degrees, in two solvent mixtures: medium 1-acetic acid 0.3mol/L and sodium acetate 0.2mol/L; and medium 2-acetic acid 0.1mol/L and sodium chloride 0.2mol/L. Different equations were employed, by graphical extrapolation, to calculate the intrinsic viscosities [?] and the viscometric constants, to reveal the solvent's quality: Huggins (H), Kraemer (K) and Schulz-Blaschke (SB). For single-point determination, the equations used were SB, Solomon-Ciuta (SC) and Deb-Chanterjee (DC), resulting in a faster form of analysis. The values of ?M¯v were calculated by applying the equation of Mark-Houwink-Sakurada. The SB and SC equations were most suitable for single-point determination of [?] and ?M¯v and the Schulz-Blachke constant (kSB), equal to 0.28, already utilized for various systems, can also be employed to analyze chitosan solutions under the conditions studied. PMID:26344278

  9. The influence of low oxygen and contaminated sodium environments on the fatigue behavior of solution treated AISI 316 stainless steel

    International Nuclear Information System (INIS)

    The influence of air and sodium environments on the fatigue properties of solution treated AISI 316 steel was studied by predictive methods and by conducting tests in air, in high temperature sodium, or following pre-exposure to sodium. The sodium environments studied included contaminated sodium or the products of sodium/water flames possibly typical of fast reactor fault conditions, and low oxygen sodium more appropriate to normal plant operation. Generally, fatigue properties were reduced by contaminated sodium or the products of sodium/water flames and improved by low oxygen sodium when compared with similar tests conducted in air. However, complex effects were observed with respect to crack initiation. The experimental results are discussed and generally follow trends predicted by physically based fatigue models. (author)

  10. The influence of low oxygen and contaminated sodium environments on the fatigue behaviour of solution treated AISI 316 stainless steel

    International Nuclear Information System (INIS)

    The influence of air and sodium environments on the fatigue properties of solution treated AISI 316 steel was studied by predictive methods and by conducting tests in air, in high temperature sodium, or following pre-exposure to sodium. The sodium environments studied included contaminated sodium or the products of sodium/water flames possibly typical of fast water reactor fault conditions, and low oxygen sodium more appropriate to normal plant operation. Generally, fatigue properties were reduced by contaminated sodium or the products of sodium/water flames and improved by low oxygen sodium when compared with similar tests conducted in air. However, complex effects were observed with respect to crack initiation. The experimental results are discussed and generally follow trends predicted by physically based fatigue models. (author)

  11. The Dissolution of Synthetic Na-Boltwoodite in Sodium Carbonate Solutions

    International Nuclear Information System (INIS)

    Uranyl silicates such as uranophane and Na-boltwoodite appear to control the solubility of uranium in the contaminated sediments at the US Department of Energy Hanford site (Liu et al., 2004). Consequently, the solubility of synthetic Na-boltwoodite was determined over a wide range of bicarbonate concentrations, from circumneutral to alkaline pH, that are representative of porewater and groundwater compositions at the Hanford site. Results show that Na-boltwoodite dissolution was nearly congruent and its solubility increased with increasing bicarbonate concentration. Calculated solubility constants varied by nearly 2 log units from low bicarbonate (no added NaCO3) to 50 mmol/L bicarbonate. However, the solubility constants only vary by 0.5 log units from 0 added bicarbonate to 1.2 mmol/L bicarbonate, where logKsp = 5.39-5.92 and the average logKsp = 5.63. No systematic trend in logKsp was apparent over this range in bicarbonate concentrations. LogKsp values trended down with increasing bicarbonate concentration, where logKsp = 4.06 at 50 mmol/L bicarbonate. We conclude that the calculated solubility constants at high bicarbonate are compromised by an incomplete or inaccurate uranyl-carbonate speciation model

  12. Kikuchi-Fujimoto disease presenting after consumption of 'Miracle Mineral Solution' (sodium chlorite).

    Science.gov (United States)

    Loh, John Ming Ren; Shafi, Humaira

    2014-01-01

    We present a case report of a 41-year-old woman of Malay ethnicity who presented with an 11-day history of fever and left-sided lymphadenopathy after consuming 'Miracle Mineral Solution' (sodium chlorite solution) for the first time. A diagnosis of Kikuchi-Fujimoto disease was established via lymph node biopsy after other differentials were excluded. The aetiology of Kikuchi-Fujimoto disease remains controversial, but viral, autoimmune and physicochemical causes have been suggested as possibilities. In this case, we hypothesise that oxidative injury from sodium chlorite initiated an inflammatory response, which triggered the onset of Kikuchi-Fujimoto disease. PMID:25422331

  13. Spectroscopic and redox properties of curium and californium ions in concentrated aqueous carbonate-bicarbonate media

    International Nuclear Information System (INIS)

    Multimilligram quantities of trivalent curium-248 and californium-249 were investigated by absorption spectroscopy, cyclic voltammetry, and bulk solution electrolysis in concentrated aqueous carbonate-bicarbonate solution. Actinide concentrations between 10-4 and 10-2M were studied in 2 M sodium carbonate and 5.5 M potassium carbonate solutions at pH values from 8 to 14. The solution absorption spectra of Cm(III) and Cf(III) in carbonate media are presented for the first time and compared to literature spectra of these species in noncomplexing aqueous solution. It was anticipated that carbonate complexation of the actinide ions could provide a sufficient negative shift in the formal potentials of the M(IV)/M(III) couples of Cm and Cf to permit the generation and stabilization of their tetravalent states in aqueous carbonate-bicarbonate medium. No conclusive evidence was found in the present work to indicate the existence of any higher oxidation states of curium or californium in carbonate solution. Some possible reasons for our inability to generate and detect oxidized species of curium and californium in this medium are discussed

  14. Is bicarbonate buffer suitable as a dissolution medium?

    Science.gov (United States)

    Boni, Julia Elisabeth; Brickl, Rolf Stefan; Dressman, Jennifer

    2007-10-01

    The objectives of this study were to compare two methods for the preparation of bicarbonate buffer, and to compare media prepared with bicarbonate buffer with commonly used biorelevant and pharmacopoeial media in terms of their suitability for dissolution testing. The various media were compared with regard to ease of preparation, robustness and reproducibility of composition. The dissolution of three formulations of a typical Biopharmaceutical Classification System Class II drug (BIXX) was compared in bicarbonate buffer, standard phosphate buffer, a biorelevant buffer (fasted-state simulating intestinal fluid, FaSSIF) and a modified FaSSIF prepared with bicarbonate buffer. The bicarbonate buffer used for dissolution testing was produced by supplying carbon dioxide to a saline solution (0.9% NaCl, to which 12 or 42 mmol NaOH had been added). The bicarbonate buffer had to be prepared in-situ, which proved to be time-consuming, and the pH stability of the bicarbonate buffer could only be maintained under constant CO2 supply. To minimize the mechanical stress caused by inflow and evaporation of gas, the carbon dioxide was supplied above the medium during the dissolution test. Despite taking these measures, use of bicarbonate buffer led to less reproducible dissolution results than the phosphate buffers commonly used to prepare compendial media and FaSSIF, with coefficient of variance values 1.5- to 5-times higher in bicarbonate buffer. It was concluded that although a bicarbonate buffer system would be physiologically relevant for the fasted state in the small intestine, its suitability for dissolution testing is restricted by lack of practicability and poor reproducibility of results. PMID:17910812

  15. Actinyl(6) speciation in concentrated sodium chloride solutions

    International Nuclear Information System (INIS)

    Thermodynamic parameters and sorption coefficients provide the fundamental database for the mathematical abstraction of environmental transport of actinides. We have been investigating the chemistry of the hexavalent actinides, U and Pu, in the solid state in concentrated salt (NaCl) solutions representative of conditions within geologic salt formations, sites for nuclear waste disposal. Chloride complexation is proven to play an important role for actinyl(VI) solubility and speciation. We investigated U(VI) and Pu(VI) equilibria with the predominant inorganic ligands hydroxide and carbonate in the presence of chloride. We used a number of spectroscopic techniques (UV-vis-NIR, Raman, FTIR, NMR, XAS) and X-ray diffraction to characterise solution species and solid phases as a function of pH, carbonate concentration, and ionic strength. (authors)

  16. Electrochemical Evaluation of Stainless Steels in Acidified Sodium Chloride Solutions

    Science.gov (United States)

    Calle, L. M.; MacDowell, L. G.; Vinje, R. D.

    2004-01-01

    This paper presents the results of an investigation in which several 300-series stainless steels (SS): AISI S30403 SS (UNS S30403), AISI 316L SS (UNS S31603), and AISI 317L SS (LINS S31703), as well as highly-alloyed: SS 254-SMO (UNS S32154), AL-6XN (N08367) and AL29-4C (UNS S44735), were evaluated using DC electrochemical techniques in three different electrolyte solutions. The solutions consisted of neutral 3.55% NaCl, 3.55% NaCl in 0.1N HCl, and 3.55% NaCl in 1.0N HCl. These solutions were chosen to simulate environments that are less, similar, and more aggressive, respectively, than the conditions at the Space Shuttle launch pads. The electrochemical test results were compared to atmospheric exposure data and evaluated for their ability to predict the long-term corrosion performance of the subject alloys. The electrochemical measurements for the six alloys indicated that the higher-alloyed SS 254-SMO, AL29-4C, and AL-6XN exhibited significantly higher resistance to localized corrosion than the 300-series SS. There was a correlation between the corrosion performance of the alloys during a two-year atmospheric exposure and the corrosion rates calculated from electrochemical (polarization resistance) measurements.

  17. Kinetics of de-N-acetylation of the chitin disaccharide in aqueous sodium hydroxide solution.

    Science.gov (United States)

    Khong, Thang Trung; Aachmann, Finn L; Vårum, Kjell M

    2012-05-01

    Chitosan is prepared from chitin, a process which is carried out at highly alkaline conditions, and that can be performed either on chitin in solution (homogeneous deacetylation) or heterogeneously with the chitin as a solid throughout the reaction. We report here a study of the de-N-acetylation reaction of the chitin dimer (GlcNAc-GlcNAc) in solution. The reaction was followed by (1)H NMR spectroscopy in deuterated aqueous sodium hydroxide solution as a function of time, sodium-hydroxide concentration and temperature. The (1)H NMR spectrum of GlcNAc-GlcNAc in 2.77 M deuterated aqueous sodium hydroxide solution was assigned. The interpretation of the (1)H NMR spectra allowed us to determine the rates of de-N-acetylation of the reducing and non-reducing ends, showing that the reaction rate at the reducing end is twice the rate at the non-reducing end. The total deacetylation reaction rate was determined as a function of the hydroxide ion concentration, showing for the first time that this de-N-acetylation reaction is second order with respect to hydroxide ion concentration. No significant difference in the deacetylation rates in deuterated water compared to water was observed. The activation energy for the reaction (26-54 °C) was determined to 114.4 and 98.6 kJ/mol at 2.77 and 5.5 M in deuterated aqueous sodium hydroxide solution, respectively. PMID:22424830

  18. Internal Active Thermal Control System (IATCS) Sodium Bicarbonate/Carbonate Buffer in an Open Aqueous Carbon Dioxide System and Corollary Electrochemical/Chemical Reactions Relative to System pH Changes

    Science.gov (United States)

    Stegman, Thomas W.; Wilson, Mark E.; Glasscock, Brad; Holt, Mike

    2014-01-01

    The International Space Station (ISS) Internal Active Thermal Control System (IATCS) experienced a number of chemical changes driven by system absorption of CO2 which altered the coolant’s pH. The natural effects of the decrease in pH from approximately 9.2 to less than 8.4 had immediate consequences on system corrosion rates and corrosion product interactions with specified coolant constituents. The alkalinity of the system was increased through the development and implementation of a carbonate/bicarbonate buffer that would increase coolant pH to 9.0 – 10.0 and maintain pH above 9.0 in the presence of ISS cabin concentrations of CO2 up to twenty times higher than ground concentrations. This paper defines how a carbonate/bicarbonate buffer works in an open carbon dioxide system and summarizes the analyses performed on the buffer for safe and effective application in the on-orbit system. The importance of the relationship between the cabin environment and the IATCS is demonstrated as the dominant factor in understanding the system chemistry and pH trends before and after addition of the carbonate/bicarbonate buffer. The paper also documents the corollary electrochemical and chemical reactions the system has experienced and the rationale for remediation of these effects with the addition of the carbonate/bicarbonate buffer.

  19. Dynamics of dihydrogen bonding in aqueous solutions of sodium borohydride.

    Science.gov (United States)

    Giammanco, Chiara H; Kramer, Patrick L; Fayer, Michael D

    2015-02-26

    Dihydrogen bonding occurs between protonic and hydridic hydrogens which are bound to the corresponding electron withdrawing or donating groups. This type of interaction can lead to novel reactivity and dynamic behavior. This paper examines the dynamics experienced by both borohydride and its dihydrogen-bound water solvent using 2D-IR vibrational echo and IR pump-probe spectroscopies, as well as FT-IR linear absorption experiments. Experiments are conducted on the triply degenerate B-H stretching mode and the O-D stretch of dilute HOD in the water solvent. While the B-H stretch absorption is well separated from the broad absorption band of the OD of HOD in the bulk of the water solution, the absorption of the ODs hydrogen bonded to BHs overlaps substantially with the absorption of ODs in the bulk H?O solution. A subtraction technique is used to separate out the anion-associated OD dynamics from that of the bulk solution. It is found that both the water and borohydride undergo similar spectral diffusion dynamics, and these are very similar to those of HOD in bulk water. Because the B-H stretch is triply degenerate, the IR pump-probe anisotropy decays very rapidly, but the decay is not caused by the physical reorientation of the BH?? anions. Spectral diffusion occurs on a time scale longer than the anisotropy decay, demonstrating that spectral diffusion is not yet complete even when the transition dipole has completely randomized. To prevent chemical decomposition of the BH??, 1 M NaOH was added to stabilize the system. 2D-IR experiments on the OD stretch of HOD in the NaOH/water liquid (no borohydride) show that the NaOH has a negligible effect on the bulk water dynamics. PMID:25635342

  20. Bicarbonate supplementation enhanced biofuel production potential as well as nutritional stress mitigation in the microalgae Scenedesmus sp. CCNM 1077.

    Science.gov (United States)

    Pancha, Imran; Chokshi, Kaumeel; Ghosh, Tonmoy; Paliwal, Chetan; Maurya, Rahulkumar; Mishra, Sandhya

    2015-10-01

    The aim of the present study was to find out the optimum sodium bicarbonate concentration to produce higher biomass with higher lipid and carbohydrate contents in microalgae Scenedesmus sp. CCNM 1077. The role of bicarbonate supplementation under different nutritional starvation conditions was also evaluated. The results clearly indicate that 0.6 g/L sodium bicarbonate was optimum concentration resulting in 20.91% total lipid and 25.56% carbohydrate along with 23% increase in biomass production compared to normal growth condition. Addition of sodium bicarbonate increased the activity of nutrient assimilatory enzymes, biomass, lipid and carbohydrate contents under different nutritional starvation conditions. Nitrogen starvation with bicarbonate supplementation resulted in 54.03% carbohydrate and 34.44% total lipid content in microalgae Scenedesmus sp. CCNM 1077. These findings show application of bicarbonate grown microalgae Scenedesmus sp. CCNM 1077 as a promising feedstock for biodiesel and bioethanol production. PMID:26142998

  1. Clinical effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose during the transconjunctival approach for orbital wall reconstruction.

    Science.gov (United States)

    Kang, Byung Wan; Lee, Hyo Seok; Oh, Han Jin; Yoon, Kyung Chul

    2012-08-01

    This study aimed to evaluate the anti-adhesive effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC, Guardix-sol®) during the transconjunctival approach to orbital wall reconstruction. Eighty-seven patients who underwent orbital wall reconstruction by the transconjunctival approach were enrolled in this prospective study. We applied HACMC between the orbicularis oculi muscle and the orbital septum after surgery in 47 patients and did not use it in 40 patients. Lower lid retraction and marginal reflex distance 2 (MRD(2)) were measured to analyze the degree of postoperative adhesion at 1 week and 1, 3, and 6 months. The degree of MRD(2) showed clinically significant differences at postoperative 1 week and 1 month between the HACMC and control groups (p<0.05). Lower lid ectropion developed in two patients (5.0%) in the control group but did not occur in the HACMC group. In orbital wall reconstruction by the transconjunctival approach, the HACMC mixture solution is effective for preventing adhesion and lower lid ectropion during the early postoperative period. PMID:22977754

  2. Antiadhesive effect of mixed solution of sodium hyaluronate and sodium carboxymethylcellulose after blow-out fracture repair.

    Science.gov (United States)

    Lee, Jong Mi; Baek, Sehyun

    2012-11-01

    Treatment of blow-out fractures is aimed at the prevention of permanent diplopia and cosmetically unacceptable enophthalmos. Porous polyethylene sheets are one of the most common alloplastic implants for blow-out fracture repair. Because adhesion between the porous polyethylene and the orbital soft tissue can result in restrictions of ocular motility, prevention of postoperative adhesion is important in the reconstruction of blow-out fractures. The purpose of this study was to find out the effect of the mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC) on postoperative adhesion in blow-out fracture repair in an animal model.Twenty-four New Zealand white rabbits were used. An 8-mm defect was made in the maxillary sinuses including the bone and mucosa. A 10-mm porous polyethylene sheet (Medpor; Porex Surgical Inc., Newnan, GA) was inserted in to the defect. The rabbits were divided into a control group and a HACMC group. In the HACMC group, HACMC solution was instilled onto the surface of the implant and then the implant was inserted. The implants were harvested at 1, 2, 4, and 8 weeks after surgery (3 implants each period). Hematoxylin and eosin, Masson trichrome, and CD31 (platelet endothelial cell adhesion molecule-1) stains were performed for evaluation of inflammation, fibrosis, and vascularization.Inflammation appeared less severe in the HACMC group, but the difference between the 2 groups was not statistically significant. The degree of fibrosis was more severe in the control group. There were significant differences in the degree of fibrosis between the 2 groups 4 and 8 weeks after surgery (P = 0.046). The amount of vascularization was similar in both groups.The HACMC solution seemed to be effective for reducing postoperative adhesion in reconstruction of blow-out fractures in a rabbit model. Our results suggest that the application of HACMC solution could be an effective adjunct for the repair of trap-door fractures or revision of blow-out fractures. PMID:23172432

  3. Thermal diffusion processes in aqueous sodium chloride solutions

    International Nuclear Information System (INIS)

    The experimental results for the Soret coefficients are variable, but suggest a trend with NaCl concentration that is consistent with electrolyte solution behavior. The temperature dependence of the Soret coefficients is in approximate agreement with previous measurements obtained using other techniques. In general, the Soret coefficient values are best interpreted based on the expansion of the fluid inclusion migration fields. The high temperature values for σ at 1.0 N NaCl concentration suggest an expansion of the migration field to smaller inclusion sizes, which for a single halite crystal at these conditions, approach a dimension of one micron. The corresponding fluid inclusion size for the polycrystalline material, where grain boundaries retard the migration, is approximately 10 microns. Although the Soret results obtained in the present study provide additional data for high temperature applications in nuclear waste isolation, more experimentation and new equipment design are required in order to obtain data at temperatures above 80 degree C. The experimental approach utilized in this study is limited in that respect. The almost immeasurable nature of the thermal diffusion process for the brines as examined in the laboratory, suggests that this effect will be insignificant (outside of fluid inclusion migration) in most rock-water interactions associated with a rocksalt nuclear waste repository. Other effects, such as convective fluid transport, pressure solution, and groundwater flow, will be orders-of-magnitude more important in evaluating the critical nature of brine migration, waste canister corrosion, and the potential for leaching radioisotopes from waste repositories

  4. Effects of angiotensin II and ionomycin on fluid and bicarbonate absorption in the rat proximal tubule

    International Nuclear Information System (INIS)

    Microperfusion of proximal convoluted tubule(PCT) and peritubular capillaries was performed to examine the effects of angiotensin II(Ang II) and ionomycin on fluid and bicarbonate absorption. Bicarbonate was determined by microcalorimetry and C-14 inulin was used as a volume marker. The rates of bicarbonate absorption (JHCO3) was 143 peq/min x mm and fluid absorption(Jv) was 2.70 nl/min x mm, when PCT and capillary perfusate contained normal Ringer solution. Addition of Ang II (10-6M) to the capillary perfusate caused reductions of JHCO3 and Jv by 35%. A similar effect was observed when ionomycin was added to the capillary perfusate. Ang II antagonist, (Sar1, Ile8)-Angiotensin II(10-6M), completely blocked the inhibitory effect of Ang II on Jv and JHCO3. Removal of calcium from both luminal and capillary perfusate did not change the effect of Ang II on Jv and JHCO3. Our results indicate that Ang II inhibits the sodium-hydrogen exchanger in the proximal tubule via interacting with angiotensin receptor. The mechanism of Ang II action may involve mobilization of intracellular calcium

  5. An empirical model to estimate density of sodium hydroxide solution: An activator of geopolymer concretes

    Science.gov (United States)

    Rajamane, N. P.; Nataraja, M. C.; Jeyalakshmi, R.; Nithiyanantham, S.

    2016-02-01

    Geopolymer concrete is zero-Portland cement concrete containing alumino-silicate based inorganic polymer as binder. The polymer is obtained by chemical activation of alumina and silica bearing materials, blast furnace slag by highly alkaline solutions such as hydroxide and silicates of alkali metals. Sodium hydroxide solutions of different concentrations are commonly used in making GPC mixes. Often, it is seen that sodium hydroxide solution of very high concentration is diluted with water to obtain SHS of desired concentration. While doing so it was observed that the solute particles of NaOH in SHS tend to occupy lower volumes as the degree of dilution increases. This aspect is discussed in this paper. The observed phenomenon needs to be understood while formulating the GPC mixes since this influences considerably the relationship between concentration and density of SHS. This paper suggests an empirical formula to relate density of SHS directly to concentration expressed by w/w.

  6. Electrochemical performance of vanadium in sodium chloride solution

    International Nuclear Information System (INIS)

    The changes of electrochemical parameters on vanadium in 0.5 M NaCl solution at different potentials ranging from - 0.155 (Ecorr) to 1000 mV (SCE) are studied using the AC impedance method. It is found that the charge-transfer resistance decreases with increasing potential. At potentials ?500 mV both the metal charge-transfer and diffusion processes occur on the electrode. At potentials more than 500 mV, the electrode reaction is under metal charge-transfer control. Study of the effect of temperature on the vanadium at open circuit potential and the value of activation energy support one-electron transfer step as the rate determining corrosion process. (orig.)

  7. Molecular interaction studies of glycylglycine in aqueous sodium halide solutions at 303, 308 and 313k

    Directory of Open Access Journals (Sweden)

    R. Palani

    2010-12-01

    Full Text Available Ultrasonic velocity, density and viscosity have been measured for glycylglycine in aqueous sodium halide (NaF, NaCl, NaBr mixture (0.5m at 303, 308 and 313K. Using the experimental values, the adiabatic compressibility, hydration number, apparent molal compressibility, apparent molal volume, limiting apparent molal compressibility, limiting apparent molal volume and their constants (SK, SV, transfer volumes at infinite dilution and viscosity B-coefficient of Jones-Dole equation were calculated. These parameters have been interpreted the molecular interactions in terms of solute-co-solute and solute-solvent interaction present in the given solutions.

  8. Effects of pressure, temperature, and concentration on the viscosity of an aqueous solution of sodium chloride

    International Nuclear Information System (INIS)

    The effects of pressure (0.1-375 MPa), temperature (283.15-323.15 K), and concentration (0.5-3 mol/kg) on the viscosity of aqueous sodium chloride solution, namely, the activation energy and B coefficient, are measured. 27 refs., 6 figs., 1 tab

  9. Does bicarbonated mineral water rich in sodium change insulin sensitivity of postmenopausal women? ¿Modifica el agua mineral bicarbonatada rica en sodio la sensibilidad a la insulina de las mujeres postmenopáusicas?

    Directory of Open Access Journals (Sweden)

    S. Schoppen

    2007-10-01

    Full Text Available Aim: To study the effects of drinking 0.5 L of two sodium-rich bicarbonated mineral waters (BMW-1 and 2, with a standard meal, on postprandial insulin and glucose changes. And to determine, if the effects vary depending on insulin resistance, measured by homeostasis model assessment (HOMA. Methods: In a 3-way randomized crossover study, 18 healthy postmenopausal women consumed two sodiumrich BMWs and a low-mineral water (LMW with a standard fat-rich meal. Fasting and postprandial blood samples were taken at 30, 60 and 120 min. Serum glucose, insulin, cholesterol and triacylglycerols were determined. Insulin resistance was estimated by HOMA and insulin sensitivity was calculated by quantitative insulin sensitivity check index (QUICKY. Results: Glucose levels did not change. HOMA and QUICKY values were highly inversely correlated (r = -1,000; p Objetivo: Estudiar los efectos de la ingesta de 0.5L de dos aguas minerales bicarbonatadas ricas en sodio (BMW-1 y 2, junto con una comida estándar, sobre los cambios en la insulina y la glucosa postprandial; y determinar si los posibles efectos varían en función de la resistencia a la insulina evaluada a través del modelo homeostático (HOMA. Métodos: 18 mujeres postmenopáusicas sanas participaron en un estudio triple cruzado aleatorizado, en el que bebieron 2 aguas minerales bicarbonatadas ricas en sodio (BMW-1 y 2 y un agua mineral débil (LMW junto con una comida estándar rica en grasa. Se tomaron muestras de sangre en ayunas y postprandiales a los 30, 60 y 120 min. Se determinó glucosa, insulina, colesterol y triglicéridos en suero. La resistencia a la insulina fue estimada a través del HOMA y la sensibilidad a la insulina se calculó mediante el índice de sensibilidad cuantitativa a la insulina (QUICKY. Resultados: Los niveles de glucosa no presentaron cambios. Los valores de HOMA y QUICKY presentaron una fuerte correlación inversa (r = -1,000; p < 0,0001. Las concentraciones de insulina mostraron un efecto significativo en el tiempo (p < 0,0001 y una interacción agua x tiempo significativa (p < 0,021. A los 120 min los niveles de insulina fueron significativamente inferiores con BMW1 respecto a LMW (p = 0,022. Las concentraciones postprandiales de insulina mostraron patrones significativamente distintos según el tipo de agua que se bebía dependiendo de los n-tiles del HOMA (p = 0,016. Conclusión: Los resultados sugieren un aumento de la sensibilidad a la insulina tras el consumo de las dos aguas minerales bicarbonatadas ricas en sodio. Este efecto es más marcado en las mujeres que tienen unos valores de HOMA más altos. Este tipo de aguas deberían ser consideradas como parte de una dieta saludable con objeto de prevenir la resistencia a la insulina y las enfermedades cardiovasculares.

  10. Bicarbonate kinetics in Indian males

    Indian Academy of Sciences (India)

    T Raj; R Kuriyan; A V Kurpad

    2006-06-01

    Measurement of rates of in vivo substrate oxidation such as that of glucose, fatty acids and amino acids, are based on tracer (14C or 13C) data, and often depend on the isotopic content of expired CO2. The recovery of tracer-labelled CO2 generated from the oxidation of 13C labelled substrates may not be 100% over short term. This can lead to underestimation of oxidation rate of substrates, and consequently a correction for the incomplete recovery of tracer has to be applied by the determination of the recovery of 13CO2 in the breath during tracer bicarbonate infusions. We have studied the recovery of tracer-labelled bicarbonate using a bolus administration model, and further characterized kinetics of bicarbonate using a three-compartment model, to assess which compartmental fluxes changed during the change from a fasted state to fed state. Recovery of bicarbonate was lower at 69% and 67% (fasted and fed state) than the value of 71% and 74% found during earlier longer term of continuous infusions. During feeding, there was a 20-fold increase in the flux of bicarbonate between the central compartment and the compartment that was equivalent to the viscera. This study shows that the difference between the fasted and fed state recovery of tracer bicarbonate similar to that obtained with continuous infusions, and that bicarbonate fluxes show large changes between different compartments in the body depending on metabolic state.

  11. Concentration of rhenium from dilute sodium chloride solutions

    Directory of Open Access Journals (Sweden)

    DRAGOLJUB M. LUKIC

    2008-03-01

    Full Text Available The conditions for the desorption of rhenium from the anion exchange resin Dowex 1-x8 by HNO3, HCl, H2SO4 and NaOH were determined. The solution (5.0´10-3 mol dm-3 Re in 0.15 mol dm-3 NaCl was passed through a column containing 0.10 g of the resin. The total sorbed amount of rhenium was 0.20 g/g of the resin. It was then eluted by the corresponding eluent in the concentration range up to about 3.0 mol dm-3. The highest elution efficiency and the most favourable elution profile were found with 3.0 mol dm-3 HNO3. Over 77 % of the sorbed rhenium was found in the first 5 ml of the eluate. Practically all the rhenium was recovered with 20 ml of the acid. Under the given experimental conditions, HCl and H2SO4 were less favourable while NaOH was not applicable, due to very low efficiency of rhenium elution.

  12. Chloride and bicarbonate transport in rat resistance arteries

    DEFF Research Database (Denmark)

    Aalkjær, Christian; Hughes, A

    1991-01-01

    1. The role of chloride and bicarbonate in the control of intracellular pH (pHi) was assessed in segments of rat mesenteric resistance arteries (internal diameter about 200 microns) by measurements of chloride efflux with 36Cl-, of pHi with the pH-sensitive dye 2',7'-bis-(2-carboxyethyl)-5 (and-6)-carboxyfluorescein (BCECF) and of membrane potential with intracellular electrodes. 2. The main questions addressed were whether the previously demonstrated sodium-coupled uptake of bicarbonate in thes...

  13. Direct rotating ring-disk measurement of the sodium borohydride diffusion coefficient in sodium hydroxide solutions

    International Nuclear Information System (INIS)

    This paper presents the experimental determination of the diffusion coefficient of borohydride anion and solution kinematic viscosity for a large panel of NaOH + NaBH4 electrolytic solutions relevant for use as anolyte in Direct Borohydride Fuel Cells (DBFC). The diffusion coefficients have been measured by the transit-time technique on gold rotating ring-disk electrodes, and verified using other classical techniques reported in the literature, namely the Levich method and Electrochemical Impedance Spectroscopy on a gold RDE, or chronoamperometry at a gold microdisk. The agreement between these methods is generally good. The diffusion coefficients measured from the RRDE technique are however ca. twice larger than those previously reported in the literature (e.g. ca. 3 x 10-5 cm2 s-1 in 1 M NaOH + 0.01 M NaBH4 at 25 deg. C in the present study vs. ca. 1.6 x 10-5 cm2 s-1 in 1 M NaOH + 0.02 M NaBH4 at 30 deg. C in the literature, as measured by chronoamperometry at a gold microsphere), which is thoroughly discussed. Our measurements using chronoamperometry at a gold microdisk showed that such technique can yield diffusion coefficient values below what expected. The origin of such finding is explained in the frame of the formation of both a film of boron-oxide(s) at the surface of the (static) gold microdisk and the generation of H2 bubbles at the electrode surface (as a result of the heterogeneous hydrolysis at Au), which alter the access to the electrode surface and thus prevents efficient measurements. Such film formation and H2 bubbles generation is not so much of an issue for rotating electrodes thanks to the convection of electrolyte which sweeps the electrode surface. In addition, should such film be present, the transit-time determination technique on a RRDE displays the advantage of not being very sensible to its presence: the parameter measured is the time taken by a perturbation generated the disk to reach the ring trough a distance several orders of magnitude bigger than the film thickness, thus minimizing its effect.

  14. Direct rotating ring-disk measurement of the sodium borohydride diffusion coefficient in sodium hydroxide solutions

    Energy Technology Data Exchange (ETDEWEB)

    Chatenet, M. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, LEPMI, UMR 5631 CNRS/Grenoble-INP/UJF, 1130 rue de la piscine, BP75, 38402 Saint Martin d' Heres Cedex (France)], E-mail: Marian.Chatenet@phelma.grenoble-inp.fr; Molina-Concha, M.B. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, LEPMI, UMR 5631 CNRS/Grenoble-INP/UJF, 1130 rue de la piscine, BP75, 38402 Saint Martin d' Heres Cedex (France); El-Kissi, N. [Laboratoire de Rheologie, UMR 5520 CNRS/Grenoble-INP/UJF, 1301 rue de la piscine, 38041 Grenoble Cedex 9 (France); Parrour, G.; Diard, J.-P. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, LEPMI, UMR 5631 CNRS/Grenoble-INP/UJF, 1130 rue de la piscine, BP75, 38402 Saint Martin d' Heres Cedex (France)

    2009-07-15

    This paper presents the experimental determination of the diffusion coefficient of borohydride anion and solution kinematic viscosity for a large panel of NaOH + NaBH{sub 4} electrolytic solutions relevant for use as anolyte in Direct Borohydride Fuel Cells (DBFC). The diffusion coefficients have been measured by the transit-time technique on gold rotating ring-disk electrodes, and verified using other classical techniques reported in the literature, namely the Levich method and Electrochemical Impedance Spectroscopy on a gold RDE, or chronoamperometry at a gold microdisk. The agreement between these methods is generally good. The diffusion coefficients measured from the RRDE technique are however ca. twice larger than those previously reported in the literature (e.g. ca. 3 x 10{sup -5} cm{sup 2} s{sup -1} in 1 M NaOH + 0.01 M NaBH{sub 4} at 25 deg. C in the present study vs. ca. 1.6 x 10{sup -5} cm{sup 2} s{sup -1} in 1 M NaOH + 0.02 M NaBH{sub 4} at 30 deg. C in the literature, as measured by chronoamperometry at a gold microsphere), which is thoroughly discussed. Our measurements using chronoamperometry at a gold microdisk showed that such technique can yield diffusion coefficient values below what expected. The origin of such finding is explained in the frame of the formation of both a film of boron-oxide(s) at the surface of the (static) gold microdisk and the generation of H{sub 2} bubbles at the electrode surface (as a result of the heterogeneous hydrolysis at Au), which alter the access to the electrode surface and thus prevents efficient measurements. Such film formation and H{sub 2} bubbles generation is not so much of an issue for rotating electrodes thanks to the convection of electrolyte which sweeps the electrode surface. In addition, should such film be present, the transit-time determination technique on a RRDE displays the advantage of not being very sensible to its presence: the parameter measured is the time taken by a perturbation generated the disk to reach the ring trough a distance several orders of magnitude bigger than the film thickness, thus minimizing its effect.

  15. Production of I-125 radioisotope in sodium iodide solution

    International Nuclear Information System (INIS)

    Application: The Radioisotope Iodine-125 has rather long half-life, and high dose range of Gamma radiation. It will be used in two cases,in our radioisotope production department: 1-To label Radioimmunoassay Kits (RIA): T3, T4 and TSH for INVITRO investigation of Thyroid glands, in our Nuclear Medical Center in IRAN. We just started to set up Hot cell facilities and in cell equipment to supply Iodine-125 for our Radioimmunoassay Group.In this section. The above Iodine-125 will be used for labelling of their Radioimmunoassay products for Thyroid functions and also for screening of newborns for Thyroid deficiency. 2-We have also just start, the make and supply particular granules of Iodine-125 by Silver coated Iodine-125 directly and also indirectly, on the Palladium, coated Silver Wire to be used in Brachytherapy applications. Production: After filling Target with 15 g of natural Xe gas by excellent technology and closed in leak-tight allowing reactor irradiation. The target is irradiated in a nuclear reactor for 3 weeks optimally at a thermal neutron flux around ?= 1*1014 n.cm-2.s-1.After transferring irradiated target to hot cell, The aluminium capsule is opened by putting it into the punching apparatus and pushing the needle into the bottom of the aluminium capsule by turning the handle counter-clockwise. When the needle punches the aluminium. The Xe gas is released into the chimney and the I-125 radioisotope is adsorbed on the inside wall of the aluminium capsule. After this the opened aluminium capsule is pulled off from the needle by turning the handle clockwise. The opened capsule is ready to distillation. Preparation of the distillation oven and equipment: on the first occasion the oven should be heated two-times up to 550 oC for two hours each to eliminate potential contamination. After it the radioactive aluminium capsule is put into the oven and vacuum is started. This is followed by switching on the heating. The distillation is followed through 120 minutes at a temperature of 550 oC. Solutions of the required radioactive concentration are dispensed to portions into ampoules. If sterile product is required ampoules should be autoclaved for 30 minutes at a temperature of 120 oC. (author)

  16. pH and conductivity of sodium phosphate solutions. [Computer calculation

    Energy Technology Data Exchange (ETDEWEB)

    Wright, J.M.; VonNieda, G.E.

    1979-03-01

    This paper describes a computer program for the calculation of the pH and conductivity of sodium phosphate solutions over the phosphate concentration range of 1 to 10000 ppM and sodium to phosphate molar ratios of approximately 2 to 3. pH can be calculated over the temperature range of 0 to 300/sup 0/C; conductivities can be calculated over the temperature range of 0 to 50/sup 0/C. Calculated values of pH and conductivity are compred to measured values and found to be in excellent agreement. Several practical uses for the computer program are discussed.

  17. Standardization of sodium metabisulfite solution concentrations and immersion time for farmed shrimp Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Luciana Trigueiro de Andrade

    2015-03-01

    Full Text Available Sodium metabisulfite is the main additive used in the prevention of melanosis in shrimp; however, it has currently been employed with great variation in concentration by producers. Thus, the aim of the present study was to determine the correlation between the concentration of the sodium metabisulfite solution and immersion time of the whole shrimp to obtain the concentration of sulfur dioxide (SO2 in the edible muscle of farmed shrimp (Litopenaeus vannamei in accordance with the limit established by law. For this, solutions of sodium metabisulfite at different concentrations (1%, 2 %, 3 %, 4% and 5% were prepared and samples of L. vannamei shrimp (100g were immersed during 10, 20 or 30 minutes at temperature of 7°C. For all treatment assayed the concentration of SO2 was determined in the edible muscle of farmed shrimp (L. vannamei. The results show that for the conditions used in this study, the correlations were linear, with significant increase (P<0.05 in the SO2 concentration in the edible muscle of shrimps both increasing sodium metabisulfite concentration as increasing immersion times, suggesting the immersion of shrimps in a 3% solution for a time of 13 minutes in order to obtain SO2 concentration of 100ppm in its edible muscle in accordance with Brazilian legislation

  18. Thermodynamics of micelle formation in a water-alcohol solution of sodium tetradecyl sulfate

    Science.gov (United States)

    Shilova, S. V.; Tret'yakova, A. Ya.; Barabanov, V. P.

    2016-01-01

    The effects of addition of ethanol and propan-1-ol on sodium tetradecyl sulfate micelle formation in an aqueous solution are studied via microprobe fluorescence microscopy and conductometry. The critical micelle concentration, quantitative characteristics of micelles, and thermodynamic parameters of micelle formation are determined. Addition of 5-15 vol % of ethanol or 5-10 vol % of propan-1-ol is shown to result in a lower critical micelle concentration than in the aqueous solution, and in the formation of mixed spherical micelles whose sizes and aggregation numbers are less than those for the systems without alcohol. The contribution from the enthalpy factor to the free energy of sodium tetradecyl sulfate micelle formation is found to dominate in mixed solvents, in contrast to aqueous solutions.

  19. Effect of peroxodisulfate on uranium leaching with ammonium bicarbonate

    Directory of Open Access Journals (Sweden)

    Nurbek Nurpeisov

    2013-05-01

    Full Text Available In this study, uranium leaching from ore material using acid solution and bicarbonate in a presence peroxodisulfate ion was examined. For experiments two different tips of leaching methods were used: leaching in static and dynamic conditions. The determination of uranium concentrations in product solutions were analyzed by titrimetric (by ammonia vanadate solution method. The maximum yield of uranium leached with ammonium bicarbonate in a presence of ammonium peroxodisulfate (5 g/L was only 33%, which is half the corresponding value obtained by sulfuric acid (65%.

  20. Thermometric quantitative selective analysis of sodium methoxide in methanol industrial solutions

    Scientific Electronic Library Online (English)

    Flavio A., Bastos; Sabir, Khan; Eduardo H., Simões; Carlos A., Teixeira; Matthieu, Tubino.

    2013-08-01

    Full Text Available O metóxido de sódio é usado como reagente ou como catalisador em muitos processos industriais como, por exemplo, na síntese de fármacos e de biodiesel. O presente trabalho apresenta um novo e seletivo método analítico quantitativo termométrico para a determinação de metóxido de sódio em soluções de [...] metanol na presença de íons hidróxido. Para fins de comparação com o método Karl-Fischer, os dois procedimentos foram aplicados a quatro diferentes soluções de metóxido de sódio em metanol, inclusive em presença de hidróxido de sódio, e os resultados foram comparados estatisticamente mostrando total concordância. Abstract in english Sodium methoxide is used as a reagent or a catalyst in many industrial processes such as, for example, pharmaceuticals and biodiesel syntheses. This work presents a new and selective quantitative analytical thermometric method for sodium methoxide determination in methanol solutions in the presence [...] of hydroxide ions. For comparative purposes with the Karl-Fischer procedure, these two methods were applied to four different solutions of sodium methoxide in methanol, including in presence of sodium hydroxide, and the results were compared statistically showing total agreement.

  1. Corrosion of Dental Au-Ag-Cu-Pd Alloys in 0.9 % Sodium Chloride Solution

    International Nuclear Information System (INIS)

    Two Au-Ag-Cu-Pd dental casting alloys (Au:12% and 20%) used. The test solutions used 0.9 % NaCl solution (isotonic sodium chloride solution), 0.9 % NaCl solution containing 1 % lactic acid, and 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol dm-3 Na2S. The surface of two samples in three sample solutions was not natural discoloration during one year. The alloy containing 12 % gold was easily alloyed and the composition was uniform comparing with the alloy containing 20 % gold. The rest potentials have not a little effect after three months. The kinds of metals could not definitely from the oxidation and reduction waves of metal on the cyclic voltammograms. The dissolutions of gold and palladium were 12 % Au sample in the 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol dm-3 Na2S. The pH of solution had an affect on dissolution of copper, and sulfur ion had an affect on dissolution of silver. The copper dissolved amount from 20 % gold sample was about 26 times comparing with that of 12 % gold sample in the 0.9 % solution containing 1 % lactic acid. Corrosion products were silver chloride and copper chloride in NaCl solution, and silver sulfide and copper sulfide in NaCl solution containing Na2S

  2. Anodic behavior of tungsten in water-organic solutions of sodium chloride

    International Nuclear Information System (INIS)

    Anode behavior of tungsten in water-aminoalcoholic solutions of sodium chlorides is studied through the potentiostatic and potentiodynamic methods. It is shown, that introduction of monoethanomine (MEM) into the NaCl aqueous solution leads to the tungsten anode activation. It is established by the current dependence on the disk electrode rotation velocity, that the process of anode solution is subjected to the diffusion kinetics regularities. The MEM delivery to the electrode is the reaction delayed stage. The maximum solution rate and the best quality of the tungsten surface after its treatment are obtained by the MEM concentration 6M. The effect of physico-chemical properties of the studied solutions on the amide reaction velocity is indicated

  3. Evaluation of sodium lignin sulfonate as draw solute in forward osmosis for desert restoration

    KAUST Repository

    Duan, Jintang

    2014-03-01

    Sodium lignin sulfonate (NaLS), an abundant waste product of paper manufacturing, can be used in desert restoration. Combined with water and applied on arid land, NaLS has been shown to stabilize sand and provide a medium for plant growth. Here, we demonstrate that NaLS is an efficient draw solute in forward osmosis (FO) to extract water from impaired sources. The osmotic pressure of a 600. g. NaLS/kg water solution is 78. bar (7.8 MPa) as measured by freezing point depression. The FO performance using NaLS draw solute was evaluated with commercial FO membranes under various test conditions. The effects of draw solute concentration, feed salinity and membrane orientation were systematically investigated. Potential ways to optimize the process, e.g. combining fertilizer draw solutes and NaLS, are proposed. © 2013 Elsevier B.V.

  4. The sealing of excavation damaged zones in salt formations using sodium silicate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Engelhardt, Hans-Joachim; Schmidt, Holger; Borstel, Lieselotte von [DBE TECHNOLOGY GmbH, Peine (Germany). Dept. of Repository Safety

    2015-07-01

    Since many decades, pressure grouting is an effective technique of civil engineering for sealing and stabilization purposes. Due to the potential contamination of fluids, grouting is of particular importance in repositories of radioactive waste. Traditional grouts for the sealing of fine fractures are sodium silicate solutions. Laboratory and field investigations prove that the particle-free solutions can be used to permanently seal excavation damaged zones (EDZ) in salt formations, because the solid reaction products are inert or almost insoluble. EDZ permeabilities of 10{sup -17} m{sup 2} can be achieved and were determined on the basis of the injection pressures and flow rates. High grouting pressures were realized as local test loadings. Laboratory tests show the fixation of Co{sup 2+}, Ni{sup 2+}, Sr{sup 2+}, Ba{sup 2+}, [UO{sub 2}]{sup 2+} and illustrate that sodium silicates may act additionally as a chemical barrier.

  5. Study on the radiation-induced copolymerization of acrylamide with sodium acrylate in aqueous solution

    Science.gov (United States)

    Ji, H. J.; Zhang, W. X.; Sun, Z. W.; Che, J. T.; Li, Z. H.

    1993-07-01

    In present work, the mechanism of radiation-induced copolymerization of acrylamide(AM) with sodium acrylate(AANa) in aqueous solution was studied. A method to protect the copolymerization system from the crosslinking and a carbon-carbon mechanism to form gel in copolymerization reaction have been proposed. The condition to prepare the products with different molecular weight, especially with very high molecular weight were found.

  6. Small-angle neutron scattering studies of sodium butyl benzene sulfonate aggregates in aqueous solution

    Indian Academy of Sciences (India)

    O R Pal; V G Gaikar; J V Joshi; P S Goyal; V K Aswal

    2004-08-01

    The aggregation behaviour of a hydrotrope, sodium -butyl benzene sulfonate (Na-NBBS), in aqueous solutions is investigated by small-angle neutron scattering (SANS). Nearly ellipsoidal aggregates of Na-NBBS at concentrations well above its minimum hydrotrope concentration were detected by SANS. The hydrotrope seems to form self-assemblies with aggregation number of 36–40 with a substantial charge on the aggregate. This aggregation number is weakly affected by the hydrotrope concentration.

  7. Removal of Cesium from Aqueous Solutions by Sodium and Calcium Alginates

    OpenAIRE

    Maksim Y. Khotimchenko; Elena A. Podkorytova; Kovalev, Valeri V.; Elena V. Khozhaenko; Khotimchenko, Yuri S.

    2014-01-01

    Environmental pollution with radioactive materials poses a serious threat to public health. Among radioisotopes, cesium is one of the most dangerous elements which can be found in waste disposals of nuclear plants and similar facilities. Pure sodium and calcium alginic salts were investigated as adsorbents for removal of cesium ions from aqueous solution. It was found that both polysaccharides form complexes with the metal ions. Batch equilibrium experiments were...

  8. Small angle neutron scattering studies of ionic micellar solutions of sodium p. octylbenzenesulfonate

    International Nuclear Information System (INIS)

    Ionic micellar solutions of sodium p octylbenzenesulfonate have been studied, by small angle scattering of neutrons. A contrast variation method applied both to solvent and the paraffinic core of the micelle allows to determine all the micellar parameters by two methods of analysis. The results obtained by the two methods are very coherent, showing in a first approximation that correlation effects are eliminated by this procedure

  9. Passivation of chalcopyrite during the leaching with sulphuric acid solution in presence of sodium nitrate

    OpenAIRE

    Soki? Miroslav D.; Matkovi? Vladislav Lj.; Markovi? Branislav R.; Štrbac Nada D.; Živkovi? Dragana T.

    2010-01-01

    In this work, the process of the chalcopyrite leaching in sulphuric acid solution was investigated. Sodium nitrate was used as oxidant in the leaching process. Chemical reactions of leaching and their thermodynamic possibilities are predicted based on the calculated Gibbs energies and analysis of E?pH diagrams. The negative values of the Gibbs energy show that all chemical reactions are thermodynamically feasible at atmospheric pressure and in a temperature range 25-90°C. At high electrode po...

  10. Performance of cellulose acetate butyrate membranes in hyperfiltration of sodium chloride and urea feed solution

    Science.gov (United States)

    Wydeven, T.; Leban, M.

    1973-01-01

    Cellulose acetate butyrate (CAB) membranes are shown to give high salt and urea rejection with water flux of about 3 gallons/sq ft per day at 600 psig. Membranes prepared from a formulation containing glyoxal show a significant increase in flux and decrease in salt and urea rejection with drying time. Zero drying time gives maximum urea and salt rejection and is therefore most suitable for hyperfiltration of sodium chloride and urea feed solution.

  11. Concentration dependence of activation energy and conductivity of aqueous solutions of sodium selenite and potassium tellurite

    International Nuclear Information System (INIS)

    Temperature and concentration dependences of electric conductivity of sodium selenite and potassium tellurite aqueous solutions in the range of temperatures from 15 to 50 Deg C were studied. Activation energy of specific electric conductivity of both electrolytes for different concentrations of solution was calculated. The dependence defined is interpreted in the light of the Samojlov theory on positive and negative hydration of ions. Analysis of the results suggests the assumption that the more pronounced is positive hydration of ions, the higher are the values of activation energy of the salts specific electric conductivity

  12. Critical role of bicarbonate and bicarbonate transporters in cardiac function

    OpenAIRE

    Wang, Hong-Sheng; Chen, Yamei; Vairamani, Kanimozhi; Shull, Gary E

    2014-01-01

    Bicarbonate is one of the major anions in mammalian tissues and extracellular fluids. Along with accompanying H+, HCO3- is generated from CO2 and H2O, either spontaneously or via the catalytic activity of carbonic anhydrase. It serves as a component of the major buffer system, thereby playing a critical role in pH homeostasis. Bicarbonate can also be utilized by a variety of ion transporters, often working in coupled systems, to transport other ions and organic substrates across cell membrane...

  13. Ternary solution of sodium chloride, succinic acid and water ? surface tension and its influence on cloud droplet activation

    OpenAIRE

    Lihavainen, H.; Viisanen, Y; Anttila, T.; A.-P. Hyvärinen; Vanhanen, J.

    2008-01-01

    Surface tension of ternary solution of sodium chloride, succinic acid and water was measured as a function of both composition and temperature by using the capillary rise technique. Both sodium chloride and succinic acid are found in atmospheric aerosols, the former being main constituent of marine aerosol. Succinic acid was found to decrease the surface tension of water already at very low concentrations. Sodium chloride increased the surface tension linearly as a function of the concentrati...

  14. Investigation into behaviour of selenurea, sulfite and selenosulfate of sodium in solutions for precipitation of cadmium selenide films

    International Nuclear Information System (INIS)

    The behavior of selenourea, sulphite and selenosulphate of sodium has been studied in alkali solutions used for precipitating the films of cadmium selenide. The process of film formation from alkali solutions containing complex salt of cadmium, selenourea, and sodium sulphite terminates in 15-20 hours at 20 deg C and in 3-4 hours at 40 deg C, depending on pH of the solution. During this period less than 10% of selenourea can transform into sodium selenosulphate and, therefore, the main part of selenourea participates in the formation of cadmium selenide

  15. The elimination of selenium(IV) from aqueous solution by precipitation with sodium sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Geoffroy, N., E-mail: nicolas.geoffroy@mail.mcgill.ca [McGill University, 3610 University Street, Montreal, QC H3A 2B2 (Canada); Demopoulos, G.P., E-mail: george.demopoulos@mcgill.ca [McGill University, 3610 University Street, Montreal, QC H3A 2B2 (Canada)

    2011-01-15

    In this study, the removal/precipitation of selenium with sodium sulfide from initially weakly acidic sulfate solutions containing 300 mg/L of selenium(IV) at 23 {sup o}C was studied. The results showed that, below a pH of approximately 7.0, the precipitation reaction was complete at a sulfide to selenium ratio above 1.8 and less than 11 with less than 0.005 mg/L of soluble selenium remaining in solution. When the pH rose between 7.0 and 9.5 the precipitation of selenium was incomplete. Above pH 9.5 the solution turned dark red but no precipitation was apparent. The precipitation reaction started as soon as the sodium sulfide was added in the selenium-bearing solution and was completed in less than 10 min. The orange 'selenium sulfide' precipitates, characterized using X-ray diffraction, scanning electron microscopy and chemical analysis, were crystalline in the form of aggregated dense particles with their sulfur/selenium molar ratio varying from 1.7 to 2.3. The precipitate was deduced to be a Se-S solid solution consisting of ring molecules of the following Se{sub n}S{sub 8-n} formula, where n = 2.5-3. Long term leachability tests (>2 month equilibration) under ambient conditions at pH 7 showed the produced precipitate to be essentially insoluble (<0.005 mg/L).

  16. In-Situ Method for Treating Residual Sodium

    Science.gov (United States)

    Sherman, Steven R.; Henslee, S. Paul

    2005-07-19

    A unique process for deactivating residual sodium in Liquid Metal Fast Breeder Reactor (LMFBR) systems which uses humidified (but not saturated) carbon dioxide at ambient temperature and pressure to convert residual sodium into solid sodium bicarbonate.

  17. Reduction of mercury from mackerel fillet using combined solution of cysteine, EDTA, and sodium chloride.

    Science.gov (United States)

    Hajeb, P; Jinap, S

    2012-06-13

    An acidic solution containing mercury chelating agents to eliminate mercury in raw fish (mackerel) fillet was developed. The solution contained hydrochloric acid, sodium hydroxide, cysteine, EDTA, and NaCl. The optimum conditions for mercury reduction were achieved using response surface methodology (RSM) at cysteine concentration of 1.25%, EDTA of 275 mg/L, NaCl of 0.5%, pH of 3.75, and exposure time of 18 min. The optimized conditions produced a solution which can remove up to 91% mercury from raw fish fillet. Cysteine and EDTA were identified as potential chelating agents with the greatest potential for use. The solution can be employed in fish industries to reduce mercury in highly contaminated fish. PMID:22515475

  18. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to sodium bicarbonate and maintenance of normal blood pressure (ID 1404) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of health...... claims in relation to sodium bicarbonate and maintenance of normal blood pressure. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from...... proposed wordings, the Panel assumes that the claimed effect refers to maintenance of normal blood pressure. The Panel considers that maintenance of normal blood pressure is a beneficial physiological effect. No references were provided from which conclusions could be drawn for the scientific...

  19. On the oxygen thresholds for the reactions of liquid sodium with urania and urania-plutonia solid solutions

    International Nuclear Information System (INIS)

    Some calculations of the oxygen potential trehsholds for the reactions of liquid sodium with urania and urania-plutonia solid solutions are presented and compared with experimental data. The reactions relevant to the understanding of the behaviour of breached sodium-cooled fast reactor breeder and fuel pins are those which form a sodium uranate, Na3UO4 (tri-sodium uranium(V) tetroxide) and a sodium urano-plutonate (Na3U1sub(-)sub(x)Pusub(x)O4). The oxygen potential thresholds are thus those for the three-phase fields; sodium, urania and sodium uranate, and sodium, urania-plutonia and sodium urano-plutonate. It has been shown that there is reasonable agreement between the calculated and measured values of oxygen potential in the ternary system. For the quaternary system with plutonium concentrations equivalent to Pu:(U + Pu) ratios of 0.25 there is also reasonable agreement between experimental and calculated values of the oxygen potential of the appropriate phase field. The measured threshold oxygen potentials are very similar for the ternary and quaternary systems as predicted. The difficulty of estimating the trheshold oxygen concentration in liquid sodium from oxygen potential thresholds is illustrated by the use of different data for oxygen solubilities in sodium. The use of the vanadium wire equilibration technique to measure the threshold oxygen potentials in these systems is possible in principle; however, existing experimental results suggest that its application is not straightforward in complex systems. (orig.)

  20. Solution and film properties of sodium caseinate/glycerol and sodium caseinate/polyethylene glycol edible coating systems.

    Science.gov (United States)

    Siew, D C; Heilmann, C; Easteal, A J; Cooney, R P

    1999-08-01

    The aim of this study is to determine the effects of plasticizer hydrogen bonding capability and chain length on the molecular structure of sodium caseinate (NaCAS), in NaCAS/glycerol and NaCAS/polyethylene glycol 400 (PEG) systems. Both solution and film phases were investigated. Glycerol and PEG reduced the viscosity of aqueous NaCAS, with the latter having a greater effect. This was explained in terms of protein/plasticizer aggregate size and changes to the conformation of the caseinate chain. In the film phase, glycerol caused more pronounced changes to the film tensile strength compared with PEG. However, the effect of glycerol on film water vapor permeability was smaller. These observations are attributed to the differences in plasticizer size and hydrogen bonding strength that controls the protein-plasticizer and protein-protein interactions in the films. Glass transition calculations from the tensile strength data indicate that the distribution of bonding interactions is more homogeneous in NaCAS/PEG films than in NaCAS/glycerol films. PMID:10552668

  1. The study of sodium saturation temperatures by its oxide and azide at their simultaneous occurrence in sodium solution

    International Nuclear Information System (INIS)

    The new technique based on analysis of the signals from electro-chemical oxygen cell and hydrogen sensor located in sodium stream behind heat and mass exchanger with electromagnetic sodium mixing inside it is applied for determination of the temperature of sodium saturation by its oxide and hydride. It is revealed that apparent increase in oxygen and hydrogen dissolving with second impurity concentration growth is caused by sodium hydroxide formation. The equilibrium constant of the reaction NaOH + 2Na ? Na2O + NaH at 400 deg C is estimated. Experimental error sources and their values are analyzed

  2. Nucleation and morphology of sodium metaborate dihydrate from NaOH solution

    Science.gov (United States)

    Qin, Shiyue; Zhang, Yifei; Zhang, Yi

    2016-01-01

    Szaibelyite ore is an important boron mineral used for producing boron compounds. Sodium metaborate dihydrate can be prepared through leaching of the szaibelyite ore in NaOH solution and the leaching liquor mainly consists of NaBO2 and NaOH. In this work, the induction time for sodium metaborate dihydrate crystallized in NaOH solution from 30 to 50 °C was systematically investigated. The primary nucleation and growth mechanism were determined on the basis of the induction time measurements. The crystals of various morphologies under different crystallization conditions were obtained: the rod-like crystals preferred to form at low temperature, while the plate-like crystals formed at high temperature; when the crystallization temperature was 30 °C, the flat rod-like crystals formed at low supersaturation, while the slim rod-like crystals formed at high supersaturation. Finally, the growth mechanism of the sodium metaborate dihydrate was identified with various models and the 2D nucleation-mediated model gave satisfactory fitting results.

  3. 21 CFR 184.1733 - Sodium benzoate.

    Science.gov (United States)

    2010-04-01

    ... Substances Affirmed as GRAS § 184.1733 Sodium benzoate. (a) Sodium benzoate is the chemical benzoate of soda (C7H5NaO2), produced by the neutralization of benzoic acid with sodium bicarbonate, sodium carbonate, or... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium benzoate. 184.1733 Section 184.1733 Food...

  4. Modelling of niobium sorption on clay minerals in sodium and calcium perchlorate solutions

    International Nuclear Information System (INIS)

    The sorption behaviour of niobium on kaolinite and illite minerals in sodium and calcium perchlorate solutions was evaluated with use of the mass distribution coefficient, Rd, obtained in batch sorption experiments. Very high distribution coefficient values, about 100 m3/kg, were obtained for both minerals in the neutral pH range between 6 and 8. Values were somewhat lower at pH 5. In NaClO4 solution, the sorption of niobium starts to decrease at pH higher than 8. This is in agreement with the increase, with pH, in the proportion of anionic niobate species, which are presumed to be low or non-sorbing. A similar decrease was not observed in Ca(ClO4)2 solution, probably owing to the influence of Ca on niobium solution speciation and surface species. The surface complexation model was applied to model the Rd values. The model fitted well for the NaClO4 solution but only at pH below 9 for the Ca(ClO4)2 solution. The discrepancy between the strong sorption of niobium in calcium-bearing solution at high pH and the calculated speciation is due in part to the non-inclusion of calcium niobate solution species and Ca-Nb compounds in the present NEA and other similar thermodynamic databases.

  5. Modelling of niobium sorption on clay minerals in sodium and calcium perchlorate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ervanne, Heini; Hakanen, Martti; Lehto, Jukka [Helsinki Univ. (Finland). Laboratory of Radiochemistry

    2014-11-01

    The sorption behaviour of niobium on kaolinite and illite minerals in sodium and calcium perchlorate solutions was evaluated with use of the mass distribution coefficient, Rd, obtained in batch sorption experiments. Very high distribution coefficient values, about 100 m{sup 3}/kg, were obtained for both minerals in the neutral pH range between 6 and 8. Values were somewhat lower at pH 5. In NaClO{sub 4} solution, the sorption of niobium starts to decrease at pH higher than 8. This is in agreement with the increase, with pH, in the proportion of anionic niobate species, which are presumed to be low or non-sorbing. A similar decrease was not observed in Ca(ClO{sub 4}){sub 2} solution, probably owing to the influence of Ca on niobium solution speciation and surface species. The surface complexation model was applied to model the Rd values. The model fitted well for the NaClO{sub 4} solution but only at pH below 9 for the Ca(ClO{sub 4}){sub 2} solution. The discrepancy between the strong sorption of niobium in calcium-bearing solution at high pH and the calculated speciation is due in part to the non-inclusion of calcium niobate solution species and Ca-Nb compounds in the present NEA and other similar thermodynamic databases.

  6. Removal of sodium and chloride ions from aqueous solutions using fique fibers (Furcraea spp.).

    Science.gov (United States)

    Agudelo, Nikolay; Hinestroza, Juan P; Husserl, Johana

    2016-01-01

    Fique fibers obtained from the leaves of Furcraea spp., a highly abundant plant in the mountains of South America, may offer an alternative as biosorbents in desalination processes as they exhibit high removal capacities (13.26 meq/g for chloride ions and 15.52 meq/g for sodium ions) up to four times higher than exchange capacities commonly observed in synthetic resins. The ion removal capacity of the fibers was also found to be a function of the pH of the solution with the maximum removal of ions obtained at pH 8. Unlike most commercial ion exchange resins, our results suggest that fique fibers allow simultaneous removal of chloride and sodium ions. PMID:26942543

  7. High temperature attack of ores by a liquor containing essentially a soluble bicarbonate

    International Nuclear Information System (INIS)

    New process for high temperature oxidizing digestion of ores containing at least one metal in the uranium, vanadium and molybdenum group, by an aqueous liquor containing sodium bicarbonate and sodium carbonate in the presence of free oxygen insufflated into the reaction medium

  8. Density, thermal expansion coefficient and viscosity of sodium tetraborate (borax)-UO2 and of sodium metaborate-UO2 solutions at high temperatures

    International Nuclear Information System (INIS)

    Measurements have been performed of the density, of the volumetric thermal expansion coefficient and of the viscosity of liquid sodium tetraborate (borax) and of sodium metaborate both pure and with two different amounts of UO2 dissolved in each. The viscosity measurements have been performed for the solution of sodium tetraborate with UO2 and CeO2, and with CeO2 only as well. These data are required for the design of core-catchers based on sodium borates. The density measurements have been performed with the buoyancy method in the temperature range from 8250C to 13000C, the viscosity measurements in the temperature range 700-12500C with a modified Haake viscosity balance. The balance was previously calibrated at ambient temperature with a standard calibration liquid and at high temperatures, with data for pure borax available from the literature. (orig.)

  9. Enhanced sonochemical degradation of bisphenol-A by bicarbonate ions.

    Science.gov (United States)

    Pétrier, Christian; Torres-Palma, Ricardo; Combet, Evelyne; Sarantakos, Georgios; Baup, Stéphane; Pulgarin, César

    2010-01-01

    Sonochemical elimination of organic pollutants can take place through two degradation pathways. Molecules with relatively large Henry's law constants will be incinerated inside the cavitation bubble, while nonvolatile molecules with low Henry's law constants will be oxidised by the OH(*) ejected from the bubble of cavitation. Taking bisphenol-A as a model pollutant, this study points out an alternate degradation route, mediated by bicarbonate ions, which is significant for the elimination of micro-pollutants at concentrations present in natural waters. In this process, OH(*) radicals react with bicarbonate ions to produce the carbonate radical, which, unlike the OH(*) radical, can migrate towards the bulk of the solution and therefore induce the degradation of the micro-pollutants present in the bulk solution. As a consequence, initial degradation rate is increased by a factor 3.2 at low concentration of bisphenol-A (0.022 micromol l(-1)) in presence of bicarbonate in water. PMID:19535280

  10. Effects Of Anodic Protection On SCC Behavior Of X80 Pipeline Steel In High-pH Carbonate-Bicarbonate Solution

    Directory of Open Access Journals (Sweden)

    Zhao W.

    2015-06-01

    Full Text Available The potentiodynamic polarization test and slow strain rate tensile tests of X80 pipeline steel were performed in 0.5M Na2CO3-1M NaHCO3 solution to study the electrochemical and stress corrosion cracking properties. The results of potentiodynamic polarization test show that there is an obvious stable passive region, about from 0v to 0.8V (SCE, indicating that anodic protection is feasible. The results of slow strain rate tensile tests show that the stress corrosion cracking sensibility is high and cathodic protection effect is restricted due to the hydrogen permeation. However, the elongation, yielding strength and tensile strength all increase with anodic protection. The higher anodic protection potential in the stable passive region is benefit to improve tensile strength and yielding strength. However, the higher elongation is obtained at 0.5V (SCE anodic protection potential.

  11. Effects and mechanism of ozonation for degradation of sodium acetate in aqueous solution

    Directory of Open Access Journals (Sweden)

    De-min YANG

    2012-06-01

    Full Text Available The degradation efficiencies and mechanism of ozonation for the degradation of sodium acetate in aqueous solution were investigated under atmospheric pressure at room temperature (293 K. The effects of the initial pH value, reaction time, and concentrations of, , CaCl2, and Ca(OH2 on the removal rate of chemical oxygen demand (COD were studied. The results indicated that ozonation obviously improved the degradation rate of sodium acetate when the pH value of the solution was not less than 8.5. A suitable long reaction time may be helpful in increasing the COD removal rate, and a removal rate of 36.36% can be obtained after a 30-minute treatment. The COD removal rate increased firstly and decreased subsequently with the increase of the concentration (from 0 to 200 mg/L, and under the same experimental condition it reached the optimum 34.66% at the concentration of 100 mg/L. The COD removal rate was 5.26% lower when the concentration of was 200 mg/L than when there was no . The COD removal rate decreased by 15.68% when the concentration increased from 0 to 200 mg/L. has a more obvious scavenging effect in inhibiting the formation of hydroxyl radicals than . CaCl2 and Ca(OH2 could increase the degradation efficiency of sodium acetate greatly, and the COD removal rates reached 65.73% and 83.46%, respectively, after a 30-minute treatment, 29.37% and 47.10% higher, respectively, than with single ozone oxidation. It was proved that the degradation of sodium acetate in the ozonation process followed the mechanism of oxidization with hydroxyl free radicals (·OH.

  12. Determination of potassium and sodium ions with diaphragm glow discharge plasma in aqueous solution

    International Nuclear Information System (INIS)

    In the present work, a new apparatus of diaphragm glow discharge emission spectroscopy was described for the determination of potassium and sodium ions in aqueous solution. The discharge was formed in a pin hole on a dielectric diaphragm interposed between two submerged graphite electrodes. Effects of pH and applied voltage on the determination have been examined. It was found that decreasing the solution pH and increasing the applied voltage were favorable for the determination performance. Limits of detection for Na and K were 0.002 and 0.05 mg L?1 under the optimum conditions, respectively. It demonstrates that the diaphragm glow discharge emission spectroscopy is a promising technique in measurements of metal ions in aqueous solution, because no optical interferences from the electrodes were found.

  13. Fabrication and corrosion behavior of fresh porous silicon in sodium hydroxide solution

    International Nuclear Information System (INIS)

    The corrosion behavior of fresh porous silicon (f-PS) in sodium hydroxide (NaOH) solution in the presence and absence of ethanol was studied by weight loss measurements and scanning electron microscope (SEM) technique. The phenomena and progress of f-PS corrosion in 1.0 M NaOH at 318 K was obtained and described. Weight loss measurements show that the corrosion rate increases with increasing temperature and concentration of NaOH solution. Meanwhile, the corrosion rate first increases with increasing volume ratio of ethanol in 1.0 M NaOH, and then decreases. Additionally, the thermodynamic and kinetic parameters (Ea, A, ?Ha and ?Sa) for f-PS corrosion were obtained and discussed. And the effect factors (T, c and v) of f-PS corrosion in NaOH solution were studied in this paper. - Highlights: • The corrosion behavior of f-PS in NaOH solution was studied for the first time. • Phenomena and progress of f-PS corrosion in NaOH solution was obtained and described. • The effect factors (T, c and v) of f-PS corrosion in NaOH solution were studied. • The kinetic and thermodynamic parameters were obtained and discussed. • The corrosion rate can be improved by adding ethanol into NaOH solution

  14. 2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

    International Nuclear Information System (INIS)

    Highlights: ? Corrosion of API 5L X65 is effectively reduced by the addition of the inhibitor. ? The techniques include weight loss, potentiodynamic polarization, EIS and AFM. ? 2-Butyne-1,4-diol acts as a mixed-type inhibitor. ? The adsorption of 2-butyne-1,4-diol obeys Langmuir adsorption isotherm. - Abstract: The inhibition effects of 2-butyne-1,4-diol on the corrosion susceptibility of grade API 5L X65 steel pipeline in 2 M Na2CO3/1 M NaHCO3 solution were studied by electrochemical techniques and weight loss measurements. The results indicated that this inhibitor was a mixed-type inhibitor, with a maximum percentage inhibition efficiency of approximately 92% in the presence of 5 mM inhibitor. Atomic force microscopy revealed that a protective film was formed on the surface of the inhibited sample. The adsorption of the inhibitor was found to conform to the Langmuir isotherm with the standard adsorption free energy of ?21.08 kJ mol?1.

  15. 2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi Meresht, E. [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Shahrabi Farahani, T., E-mail: tshahrabi34@modares.ac.ir [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Neshati, J. [Research Institute of Petroleum Industry, RIPI, 1485733111, Tehran (Iran, Islamic Republic of)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Corrosion of API 5L X65 is effectively reduced by the addition of the inhibitor. Black-Right-Pointing-Pointer The techniques include weight loss, potentiodynamic polarization, EIS and AFM. Black-Right-Pointing-Pointer 2-Butyne-1,4-diol acts as a mixed-type inhibitor. Black-Right-Pointing-Pointer The adsorption of 2-butyne-1,4-diol obeys Langmuir adsorption isotherm. - Abstract: The inhibition effects of 2-butyne-1,4-diol on the corrosion susceptibility of grade API 5L X65 steel pipeline in 2 M Na{sub 2}CO{sub 3}/1 M NaHCO{sub 3} solution were studied by electrochemical techniques and weight loss measurements. The results indicated that this inhibitor was a mixed-type inhibitor, with a maximum percentage inhibition efficiency of approximately 92% in the presence of 5 mM inhibitor. Atomic force microscopy revealed that a protective film was formed on the surface of the inhibited sample. The adsorption of the inhibitor was found to conform to the Langmuir isotherm with the standard adsorption free energy of -21.08 kJ mol{sup -1}.

  16. Hydraulic conductivity in response to exchangeable sodium percentage and solution salt concentration

    Directory of Open Access Journals (Sweden)

    Jefferson Luiz de Aguiar Paes

    2014-10-01

    Full Text Available Hydraulic conductivity is determined in laboratory assays to estimate the flow of water in saturated soils. However, the results of this analysis, when using distilled or deionized water, may not correspond to field conditions in soils with high concentrations of soluble salts. This study therefore set out to determine the hydraulic conductivity in laboratory conditions using solutions of different electrical conductivities in six soils representative of the State of Pernambuco, with the exchangeable sodium percentage adjusted in the range of 5-30%. The results showed an increase in hydraulic conductivity with both decreasing exchangeable sodium percentage and increasing electrical conductivity in the solution. The response to the treatments was more pronounced in soils with higher proportion of more active clays. Determination of hydraulic conductivity in laboratory is routinely performed with deionized or distilled water. However, in salt affected soils, these determinations should be carried out using solutions of electrical conductivity different from 0 dS m-1, with values close to those determined in the saturation extracts.

  17. The passivation of steel in sodium sulphate solution studied by CEMS and AES

    International Nuclear Information System (INIS)

    The passive layer formed on standard steel by anodic oxidation in 0.5 M sodium sulphate solution was found to contain iron only in the trivalent state. The thickness of the layer increases with the applied potential as well as with the time the passivating potential is applied to the sample. These results, compared with the electrochemical data, lead to the suggestion that the passive behaviour is not due to the whole oxidic layer but due to a thin, low lying interfacial layer with a structural disorder. (orig.)

  18. Removal of radioactive Cs from nonwoven cloth with less waste solution using aqueous sodium metasilicate

    International Nuclear Information System (INIS)

    Remediation of nonwoven cloth contaminated with radioactive material such as 137Cs is important for the reuse of protective garments. Here, we report the effectiveness of aqueous sodium metasilicate prepared with a microbubble crushing process (SMC) in the removal of radioactive 137Cs from nonwoven cloth. The 137Cs removal ratio obtained using SMC was found to be 78%, and multiple washings at low SMC concentrations were effective. In addition, the volume of the waste solution could be reduced by neutralizing the SMC and using gelation to remove the radioactive material. (author)

  19. Influence and hydrolysis kinetics in titanyl sulfate solution from the sodium hydroxide molten salt method

    Science.gov (United States)

    Wang, Weijing; Chen, Desheng; Chu, Jinglong; Li, Jie; Xue, Tianyan; Wang, Lina; Wang, Dong; Qi, Tao

    2013-10-01

    Hydrated titanium dioxide (HTD) was precipitated by thermal hydrolysis in purified titanyl sulfate solution (TSS) obtained through the sodium hydroxide molten salt clean method. Various factors including the stirring speed and initial concentrations of TiOSO4, sulfuric acid, and sodium ion were studied. The main influence factors in the hydrolysis process were the initial concentrations of TiOSO4 and sulfuric acid. Contrary to the ferrous ion, the sodium ion improved the ionic activity of Ti4+, but did not decrease the crystal size. The Boltzman growth model (x=A2+(A1-A2)/{1+exp[(t-t0)/dt)]}, which focuses on two main parameters (CTiOSO4 and CH2SO4), fits the hydrolysis process well with R2>0.97. An increase in sulfuric acid concentration negatively affected the hydrolysis rates and the value of A2, while t0 increased. An increase in titanyl sulfate concentration directly reduced the hydrolysis rates and particle size of HTD, contrary to the trend for the value of t0. A simulation software called 1stopt was used to observe the relationship between Z (A1, A2, t0, dt) and a, b (CTiO2 and CH2SO4).

  20. Removal of Cesium from Aqueous Solutions by Sodium and Calcium Alginates

    Directory of Open Access Journals (Sweden)

    Maksim Y. Khotimchenko

    2014-01-01

    Full Text Available Environmental pollution with radioactive materials poses a serious threat to public health. Among radioisotopes, cesium is one of the most dangerous elements which can be found in waste disposals of nuclear plants and similar facilities. Pure sodium and calcium alginic salts were investigated as adsorbents for removal of cesium ions from aqueous solution. It was found that both polysaccharides form complexes with the metal ions. Batch equilibrium experiments were carried out to study the effect of contact time, initial concentration of the metal and pH of the media on the adsorption of cesium by alginate compounds. The equilibrium time was found to be 60 min for adsorption of cesium with various initial metal concentrations. Kinetic studies showed that reactions between alginates and cesium are corresponding to the pseudo-second order model. Langmuir model was found best fit within the whole range of pH values studied. The maximum adsorption capacity of calcium alginate and sodium alginate was found to be 63.69 and 80.64 mg g-1, respectively at pH 6.0. From these results it is clear that sodium alginate possesses more pronounced cesium binding capacity than calcium alginate.

  1. Process of transformation of radioactive waste of metal sodium into soda solution by reaction with an alcohol followed by hydrolysis

    International Nuclear Information System (INIS)

    Reviews of the literature and of the laboratory tests are followed by a presentation of the results obtained during experiments carried out on a model with some ten grams of sodium contaminated by radioactive materials and on an industrial pre-pilot with several kilograms of non-contaminated sodium. Sodium is converted into alcoholate through the action of ethylcarbitol (CH3CH2OCH2CH2OCH2OH) on liquid sodium in suspension in xylene at 110 deg C. Once the reaction is complete, xylene is distillated and the alcoholate is in solution in an axcess of alcohol. Hydrolysis by water gives out the initial alcohol which is then extracted from the aqueous phase by toluene. All these operations are carried out in inert atmosphere (nitrogen). Sodium is thus converted into a sodium hydroxide aqueous solution with emission of hydrogen, the intermediate products (alcohol, xylene, toluene) being recyled. The process is reliable and recycling of organic products is favourable economically. The advantage of the method is to concentrate nearly all the radioactivity of the contaminated sodium in the aqueous phase, thus avoiding the dispersion of activity especially with the gaseous effluents. Finally, data are given allowing to consider the realization of a pilot with a weekly capacity of 100 kg of sodium, in semi-continuous operation

  2. Rate constant for reaction of hydroxyl radicals with bicarbonate ions

    International Nuclear Information System (INIS)

    The rate constant for reaction of hydroxyl radicals with the bicarbonate ion has been determined to be 8.5 x 106 dm3 mol-1 s-1. This value was calculated from: the measured rate of formation of the CO3- radical in pulsed electron irradiation of bicarbonate solutions over the pH range 7.0 to 9.4; the pK for the equilibrium HCO3- = CO32-+ H+; and the rate constant for hydroxyl radicals reacting with the carbonate ion. (author)

  3. Electrolyte and glucose contents of ripe and unripe coconut liquid as source of oral rehydration solution

    OpenAIRE

    P Edomwande; Adegoke, A. O.; E O Bamigbowu; M I George-Opuda

    2012-01-01

    Summary: Electrolyte and glucose contents of 20 ripe and 20 unripe coconuts were analysed along with a commercially prepared oral rehydration solution using flame photometry for sodium, potassium and back titration method for bicarbonate estimation while glucose oxidase method was carried out for glucose estimation. The unripe coconut liquid had mean+ SEM of sodium (mmol/L) 40.08 + 3.21, potassium (mmol/l) 24.06 + 0.89, bicarbonate (mmol/l) 1.48 + 0.20 and glucose (mmol/l) 26.30 + 0.21 while ...

  4. Bicarbonate diffusion through mucus.

    Science.gov (United States)

    Livingston, E H; Miller, J; Engel, E

    1995-09-01

    The mucus layer overlying duodenal epithelium maintains a pH gradient against high luminal acid concentrations. Despite these adverse conditions, epithelial surface pH remains close to neutrality. The exact nature of the gradient-forming barrier remains unknown. The barrier consists of mucus into which HCO3- is secreted. Quantification of the ability of HCO3- to establish and maintain the gradient depends on accurate measurement of this ion's diffusion coefficient through mucus. We describe new experimental and mathematical methods for diffusion measurement and report diffusion coefficients for HCO3- diffusion through saline, 5% mucin solutions, and rat duodenal mucus. The diffusion coefficients were 20.2 +/- 0.10, 3.02 +/- 0.31, and 1.81 +/- 0.12 x 10(-6) cm2/s, respectively. Modeling of the mucobicarbonate layer with this latter value suggests that for conditions of high luminal acid strength the neutralization of acid by HCO3- occurs just above the epithelial surface. Under these conditions the model predicts that fluid convection toward the lumen could be important in maintaining the pH gradient. In support of this hypothesis we were able to demonstrate a net luminal fluid flux of 5 microliters.min-1.cm-2 after perfusion of 0.15 N HCl in the rat duodenum. PMID:7573457

  5. Effect of Ultrasound on the Decomposition of Sodium Dodecylbenzene Sulfonate in Aqueous Solution

    International Nuclear Information System (INIS)

    The influence of ultrasound frequency, dissolved gases, and initial concentration on the decomposition of sodium dodecylbenzene sulfonate(DBS) aqueous solution was investigated using ultrasound generator with 200 W ultrasound power. The decomposition rates at three frequencies(50, 200, and 600 kHz) examined under argon atmosphere were highest at 200 kHz. The highest observed decomposition rate at 200 kHz occurred in the presence of oxygen followed by air and argon, helium, and nitrogen. The effect of initial concentration of DBS on the ultrasonic decomposition was decreased with increasing initial concentration and would depend upon the formation of micelle in aqueous solution. It appears that the ultrasound frequency, dissolved gases, and initial concentration play an important role on the sonolysis of DBS. Sonolysis of DBS mainly take place at the interfacial region of cavitation bubbles by both OH radical attack and pyrolysis to alkyl chain, aromatic ring, and headgroup

  6. On the refractive index of sodium iodide solutions for index matching in PIV

    International Nuclear Information System (INIS)

    Refractive index matching has become a popular technique for facilitating applications of modern optical diagnostic techniques, such as particle image velocimetry, in complex systems. By matching the refractive index of solid boundaries with that of the liquid, unobstructed optical paths can be achieved for illumination and image acquisition. In this research note, we extend previously provided data for the refractive index of aqueous solutions of sodium iodide (NaI) for concentrations reaching the temperature-dependent solubility limit. Results are fitted onto a quadratic empirical expression relating the concentration to the refractive index. Temperature effects are also measured. The present range of indices, 1.333-1.51, covers that of typical transparent solids, from silicone elastomers to several recently introduced materials that could be manufactured using rapid prototyping. We also review briefly previous measurements of the refractive index, viscosity, and density of NaI solutions, as well as prior research that has utilized this fluid. (orig.)

  7. Corrosion performance of SiCsubp/6061 Al metal matrix composites in sodium chloride solution

    International Nuclear Information System (INIS)

    The corrosion performance of silicon carbide particle/aluminium metal matrix composites (SiCsubp/Al) were studied in sodium chloride solution by means of electrochemical, microscopic, gravimetric and analytical techniques. The materials under investigation were compocasting processed 6061 Al reinforced with increasing amounts of SiC particles. Potentiostatic polarization tests were done in 0.1M NaCl solutions that were aerated or deaerated to observe overall corrosion behaviour. It was seen that the corrosion potentials did not vary greatly in relation to the amounts of SiCsubp reinforcement. Corrosion tests showed that the degree of corrosion increased with increasing SiCsubp content. SEM analysis technique was used to study the corroded samples and the pitting morphology. By TEM, no intermetallic layer was found at SiC/Al interface. A model for pitting process was proposed

  8. On the refractive index of sodium iodide solutions for index matching in PIV

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Kunlun; Katz, Joseph [Johns Hopkins University, Department of Mechanical Engineering, Baltimore, MD (United States)

    2014-04-15

    Refractive index matching has become a popular technique for facilitating applications of modern optical diagnostic techniques, such as particle image velocimetry, in complex systems. By matching the refractive index of solid boundaries with that of the liquid, unobstructed optical paths can be achieved for illumination and image acquisition. In this research note, we extend previously provided data for the refractive index of aqueous solutions of sodium iodide (NaI) for concentrations reaching the temperature-dependent solubility limit. Results are fitted onto a quadratic empirical expression relating the concentration to the refractive index. Temperature effects are also measured. The present range of indices, 1.333-1.51, covers that of typical transparent solids, from silicone elastomers to several recently introduced materials that could be manufactured using rapid prototyping. We also review briefly previous measurements of the refractive index, viscosity, and density of NaI solutions, as well as prior research that has utilized this fluid. (orig.)

  9. Corrosion Behavior of Alloy 22 in Oxalic Acid and Sodium Chloride Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Day, S D; Whalen, M T; King, K J; Hust, G A; Wong, L L; Estill, J C; Rebak, R B

    2003-06-24

    Nickel based Alloy 22 (NO6022) is extensively used in aggressive industrial applications, especially due to its resistance to localized corrosion and stress corrosion cracking in high chloride environments. The purpose of this work was to characterize the anodic behavior of Alloy 22 in oxalic acid solution and to compare its behavior to sodium chloride (NaCl) solutions. Standard electrochemical tests such as polarization resistance and cyclic polarization were used. Results show that the corrosion rate of Alloy 22 in oxalic acid solutions increased rapidly as the temperature and the acid concentration increased. Extrapolation studies show that even at a concentration of 10{sup -4}M oxalic acid, the corrosion rate of Alloy 22 would be higher in oxalic acid than in 1 M NaCl solution. Alloy 22 was not susceptible to localized corrosion in oxalic acid solutions. Cyclic polarization tests in 1 M NaCl showed that Alloy 22 was susceptible to crevice corrosion at 90 C but was not susceptible at 60 C.

  10. Influence of hydroxypropylmethyl cellulose-sodium laurylsulfate interaction on rheological properties of the solution

    Directory of Open Access Journals (Sweden)

    Šaleti? Jelena V.

    2004-01-01

    Full Text Available Interactions between the polymers and surfactants in solution have widely been investigated because of their scientific and technological importance. These interactions can be utilized to modify the physicochemical properties of system in many food products, pharmaceutical formulations, personal care products, paints, pesticides, etc. Interaction between nonionic polymer - hydroxypropylmethyl cellulose (HPMC and anionic surfactant - sodium laurylsulfate (SDS in solution has been investigated in this paper by rheological measurements. Rheological measurements are performed by rotational viscometer at 20°C and changes of rheological characteristics of HPMC solutions (0.5-1.5% with increasing SDS concentrations (0-4.0% were determined. The results of these investigations showed that viscosity of the solution is dependant on HPMC-SDS interaction. At particular SDS concentration viscosity increases, reach maximum and after that decreases until reach constant value. From the viscosity changes the characteristic concentrations of SDS, critical aggregation concentration (cac and polymer saturation point (psp, were determined. These concentrations are in linear relationships with HPMC concentrations. Rheological properties of the solution are strong influenced by HPMC-SDS interaction and exhibits more or less pronounced pseudoplastic behavior, which changes to Newtonian one after the psp has been reached.

  11. Evaluation of poly (aspartic acid sodium salt) as a draw solute for forward osmosis.

    Science.gov (United States)

    Gwak, Gimun; Jung, Bokyung; Han, Sungsoo; Hong, Seungkwan

    2015-09-01

    Poly (aspartic acid sodium salt) (PAspNa) was evaluated for its potential as a novel draw solute in forward osmosis (FO). The inherent advantages of PAspNa, such as good water solubility, high osmotic pressure, and nontoxicity, were first examined through a series of physicochemical analyses and atomic-scale molecular dynamics simulations. Then, lab-scale FO tests were performed to evaluate its suitability in practical processes. Compared to other conventional inorganic solutes, PAspNa showed comparable water flux but significantly lower reverse solute flux, demonstrating its suitability as a draw solute. Moreover, fouling experiments using synthetic wastewater as a feed solution demonstrated that PAspNa reversely flowed to the feed side reduced inorganic scaling on the membrane active layer. The recyclability of PAspNa was studied using both nanofiltration (NF) and membrane distillation (MD) processes, and the results exhibited its ease of recovery. This research reported the feasibility and applicability of FO-NF or FO-MD processes using PAspNa for wastewater reclamation and brackish water desalination. PMID:26005789

  12. Sodium salt effect on aqueous solutions containing Tween 20 and Triton X-102

    International Nuclear Information System (INIS)

    Highlights: ? Several sodium salts act as phase promoters in aqueous solutions of two surfactants. ? Merchuck, Othmer–Tobias and Bancroft equations were used for correlating the systems. ? ?hydG and Hofmeister series were employed to analyze the different salting out effects. - Abstract: The effect of six different high charge density sodium inorganic salts, such as Na2CO3, Na2SO4, Na2S2O3, Na2SO3, Na2HPO4 and NaCH3COO, in aqueous solutions of two anionic surfactants Tween 20 and Triton X-102 was investigated at T = 298.15 K and atmospheric pressure. The results were qualitatively analyzed in the light of the Hofmeister series. Also, a quantitative thermodynamic analysis in terms of molar Gibbs free energy of hydration (?hydG) was carried out. The Merchuck equation was used to correlate the solubility curves and the tie line data were modelled by applying the Othmer–Tobias and Bancroft equations.

  13. Electrogenic bicarbonate secretion by prairie dog gallbladder.

    Science.gov (United States)

    Moser, A James; Gangopadhyay, A; Bradbury, N A; Peters, K W; Frizzell, R A; Bridges, R J

    2007-06-01

    Pathological rates of gallbladder salt and water transport may promote the formation of cholesterol gallstones. Because prairie dogs are widely used as a model of this event, we characterized gallbladder ion transport in animals fed control chow by using electrophysiology, ion substitution, pharmacology, isotopic fluxes, impedance analysis, and molecular biology. In contrast to the electroneutral properties of rabbit and Necturus gallbladders, prairie dog gallbladders generated significant short-circuit current (I(sc); 171 +/- 21 microA/cm(2)) and lumen-negative potential difference (-10.1 +/- 1.2 mV) under basal conditions. Unidirectional radioisotopic fluxes demonstrated electroneutral NaCl absorption, whereas the residual net ion flux corresponded to I(sc). In response to 2 microM forskolin, I(sc) exceeded 270 microA/cm(2), and impedance estimates of the apical membrane resistance decreased from 200 Omega.cm(2) to 13 Omega.cm(2). The forskolin-induced I(sc) was dependent on extracellular HCO(3)(-) and was blocked by serosal 4,4'-dinitrostilben-2,2'-disulfonic acid (DNDS) and acetazolamide, whereas serosal bumetanide and Cl(-) ion substitution had little effect. Serosal trans-6-cyano-4-(N-ethylsulfonyl-N-methylamino)-3-hydroxy-2,2-dimethyl-chroman and Ba(2+) reduced I(sc), consistent with the inhibition of cAMP-dependent K(+) channels. Immunoprecipitation and confocal microscopy localized cystic fibrosis transmembrane conductance regulator protein (CFTR) to the apical membrane and subapical vesicles. Consistent with serosal DNDS sensitivity, pancreatic sodium-bicarbonate cotransporter protein pNBC1 expression was localized to the basolateral membrane. We conclude that prairie dog gallbladders secrete bicarbonate through cAMP-dependent apical CFTR anion channels. Basolateral HCO(3)(-) entry is mediated by DNDS-sensitive pNBC1, and the driving force for apical anion secretion is provided by K(+) channel activation. PMID:17363467

  14. Effects of Metal Ions on Viscosity of Aqueous Sodium Carboxylmethylcellulose Solution and Development of Dropping Ball Method on Viscosity

    Science.gov (United States)

    Set, Seng; Ford, David; Kita, Masakazu

    2015-01-01

    This research revealed that metal ions with different charges could significantly affect the viscosity of aqueous sodium carboxylmethylcellulose (CMC) solution. On the basis of an Ostwald viscometer, an improvised apparatus using a dropping ball for examining the viscosity of liquids/solutions has been developed. The results indicate that the…

  15. Clinical application of sodium hyaluronate,levarterenol and indicarmine solution in endoscopic submucosal dissection

    Directory of Open Access Journals (Sweden)

    Fei GAO

    2011-07-01

    Full Text Available Objective To assess the clinical value of sodium hyaluronate,levarterenol and indicarmine solution used in endoscopic submucosal dissection(ESD.Methods Sixteen patients were involved in present study who were diagnosed as precancerous lesion or submucosal tumor in digestive tract by chromoendoscopy and endoscopic ultrasonography from Nov,2010 to Feb,2011 at General Hospital of Shenyang Command.The injected solution was mixed with 0.2% indicarmine 10ml,levarterenol 10mg,sodium hyaluronate 20mg,and 0.9% normal saline 200ml.The liquid pad was formed under the submucosal layer by the injection of the mixture.Hybrid knife was employed to perform the injection,cutting and coagulation with no interruption during the procedure of ESD.Satisfactory degree was assessed,and the total solution volume,success rate,bleeding rate,perforation rate,operation duration,and length of stay in hospital were recorded.The recurrence and healing condition were observed at following-up.Results The length of lesion was 0.8~4.5cm with mean of 2.2cm.The operation duration was 45~240 min with an mean time of 95.4 min.The mean dosage of the mixed solution for submucosal injection was 102.4ml.Success rate of endoscopic submucosal dissection was 87.5%.The satisfactory degree was high.Intractable bleeding occurred in 2 cases with lateral spreading tumor(LST during the procedure,but it was controlled after high temperature coagulation without producing perforation.The dissection surface was covered by aluminum phosphate gel in all cases,and metal clips were applied in some cases for closure.The mean length of stay in hospital after ESD was 3.8 days.Conclusions The mixture of sodium hyaluronate,levarterenol,indicarmine and normal saline,when used for submucosal injection in ESD,is safe and satisfactory.

  16. Long-term performance of bicarbonate-form anion exchange: removal of dissolved organic matter and bromide from the St. Johns River, FL, USA.

    Science.gov (United States)

    Walker, Krystal M; Boyer, Treavor H

    2011-04-01

    The goal of this research was to evaluate the long-term performance of magnetic ion exchange (MIEX) treatment using bicarbonate as the mobile counter ion (i.e., MIEX-HCO(3)) and sodium bicarbonate for regeneration. This work is important because there are many unknowns concerning the affinity and regeneration efficiency of bicarbonate-form anion exchange, whereas chloride-form anion exchange (i.e., MIEX-Cl resin) is well-studied. Raw water samples were collected approximately two times per month for one year from a single location on the St. Johns River (SJR), FL, USA. The SJR is characterized by high concentrations of dissolved organic carbon (DOC; 12-26 mg C/L) and bromide (550-1100 μg/L), and is being considered as an alternative drinking water supply. Jar tests were conducted using MIEX-HCO(3) resin, and MIEX-Cl resin was used as a baseline for comparison. The same batch of MIEX-HCO(3) and MIEX-Cl resin was used for the entire study, which was accomplished by regenerating the resins after each jar test in concentrated solutions of sodium bicarbonate and sodium chloride, respectively, and resulted in 21 regeneration cycles. Maximum removal efficiency was achieved with fresh MIEX-HCO(3) resin and virgin MIEX-Cl resin. Both forms of fresh/virgin MIEX resin also had the same affinity sequence with sulfate ≈ UV-absorbing substance > DOC > bromide. The removal efficiency of both forms of MIEX resin decreased as the number of regeneration cycles increased, with MIEX-HCO(3) resin showing 7-18% lower removals than MIEX-Cl resin after 21 regeneration cycles. The affinity sequence of regenerated MIEX-HCO(3) and MIEX-Cl resins differed from fresh resin with UV-absorbing substances > DOC > sulfate > bromide. Scanning electron microscopy and simulated MIEX-HCO(3) treatment under rapidly changing water quality were also used to improve the understanding of bicarbonate-form anion exchange. The major contribution of this research is a systematic study of the extended use of bicarbonate-form anion exchange resin in the context of affinity, regeneration efficiency, and changing water quality. PMID:21444103

  17. Molecular dynamics simulations of the solution-air interface of aqueous sodium nitrate.

    Science.gov (United States)

    Thomas, Jennie L; Roeselová, Martina; Dang, Liem X; Tobias, Douglas J

    2007-04-26

    Molecular dynamics simulations have been used to investigate the behavior of aqueous sodium nitrate in interfacial environments. Polarizable potentials for the water molecules and the nitrate ion in solution were employed. Calculated surface tension data at several concentrations are in good agreement with measured surface tension data. The surface potential of NaNO3 solutions at two concentrations also compare favorably with experimental measurements. Density profiles suggest that NO3- resides primarily below the surface of the solutions over a wide range of concentrations. When the nitrate anions approach the surface of the solution, they are significantly undercoordinated compared to in the bulk, and this may be important for reactions where solvent cage effects play a role such as photochemical processes. Surface water orientation is perturbed by the presence of nitrate ions, and this has implications for experimental studies that probe interfacial water orientation. Nitrate ions near the surface also have a preferred orientation that places the oxygen atoms in the plane of the interface. PMID:17402716

  18. Study on applicability of liquid emulsion membrane for removal of uranium from acidic sodium sulfate solution

    International Nuclear Information System (INIS)

    Liquid Emulsion Membrane (LEM) is a very prominent technique to extract heavy metals from aqueous solutions using emulsion of a suitable solvent and a strip solution. Sodium sulfate solution is one of the effluents, coming out from the phosphoric acid based Rare Material Recovery plants. The effluent contains uranium in the range of 0 to 50 ppm. For treating this effluent and to recover uranium present in it, LEM has been tried using D2EHPA as carrier and phosphoric acid (42% P2O5) as strip solution. Kinetics of the process has been studied. Different sets of experiments have been performed for initial optimization of equilibrium and process parameters like carrier concentration, surfactant concentration, emulsification RPM, emulsification time, pertraction RPM, pertraction time, phase ratio and treatment ratio. Study shows more than 90% of uranium can be extracted with aqueous to organic ratio 10:1. Major work carried out is experimental. Reduction in surfactant quantity and carrier concentration has been significant outcome of the work. The emulsion is stable even at below 2% SPAN-80 surfactant. 2% surfactant gives best results in terms of extraction and stripping.10% of D2EHPA in Heavy Normal Paraffin (HNP) gives good results. 10 minutes time is required for pertraction to give more than 95% of extraction using 10% D2EHPA. Other optimum parameters which give best results are listed

  19. Analysis of Physicochemical Properties of Aqueous Sodium Glycinate (SG Solutions at Low Concentrations from 0.1-2.0 M

    Directory of Open Access Journals (Sweden)

    M.S. Shaikh

    2014-01-01

    Full Text Available Sodium glycinate, a type of amino acid salt, is one of the potential solvent for carbon dioxide removal from various gas streams. In this study, physicochemical properties such as density, viscosity and refractive index of aqueous sodium glycinate at low concentrations were measured from 303.15 to 333.15 K. It was found that, the densities, viscosities and refractive indices of low concentrated sodium glycinate decrease with an increase in temperature, whereas with increasing the concentration in the solution, all three properties increase. The experimental data were correlated with respect to temperature and concentration by establishing the proper correlations.

  20. Thermodynamic study of the n-octane-1-pentanol-sodium dodecyl sulfate solutions in water

    International Nuclear Information System (INIS)

    The thermodynamic properties, PVTx (T S, P S, ? S) (?P/?T) VX, and C V VTx, of three microemulsions (water + n-octane + sodium dodecylsulfate + 1-pentanol) with composition of solution-1: 0.0777 (H2O):0.6997 (n-C8H18):0.0777 (SDS):0.1449 (1-C5H11OH) mass fraction; solution-2: 0.6220 (H2O):0.1555 (n-C8H18):0.0777 (SDS):0.1448 (1-C5H11OH) mass fraction; and solution-3: 0.2720 (H2O):0.5054 (n-C8H18):0.0777 (SDS):0.1449 (1-C5H11OH) mass fraction were measured. Sodium dodecylsulfate (SDS) was used as an ionic surfactant, 1-pentanol used as stabilizer (cosurfactant), and n-octane as oil component in aqueous solution. A high-temperature, high-pressure, adiabatic, and nearly constant-volume calorimeter supplemented by quasi-static thermogram technique was used for the measurements. Measurements were made at eight densities (isochores) between 475.87 and 919.03 kg m-3. The range of temperature was from 275 to 536 K and pressure range was up to 138 bar. Uncertainty of the pressure, density, derivative (?P/?T) VX, and heat capacity measurements are estimated to be 0.25%, 0.02%, 0.12-1.5%, and 2.5%, respectively. Temperatures at liquid-gas phase transition curve, T S(?), for each measured densities (isochores) were determined using a quasi-static thermogram technique. The uncertainty of the phase transition temperature measurements is about ±0.02 K. The effect of temperature, density, and concentration on the heat capacity of the microemulsions is discussed. Along the isochore of 438.40 kg m-3 at temperatures above 525.44 K for the first solution the precipitation of the solid phase (SDS) was found

  1. Corrosion behaviour of heavily deformed pearlitic and brass-coated pearlitic steels in sodium chloride solutions

    International Nuclear Information System (INIS)

    Highlights: • When coupled with brass, the corrosion rate of pearlite increases by a factor of 2. • After plastic deformation, the corrosion rate of pearlite increases by a factor of 3. • Plastic deformation has small influence on cathodic reactions. • Plastic deformation has significant influence on anodic dissolution reactions. • Dissolution of brass is divided into different steps. - Abstract: The influence of plastic deformation and galvanic coupling on the microstructure and corrosion behaviour of pearlitic steel and brass-coated pearlitic steel was investigated in sodium chloride solution at 25 °C. Microstructural changes were quantified using scanning electron microscopy coupled with EBSD. Chemical and electrochemical modifications were evaluated using XPS, ZRA, the electrochemical microcell technique and the weight loss method. From these experiments, the influence of microstructural changes on the electrochemical parameters and the corrosion rate was discussed

  2. Efficient frequency conversion by stimulated Raman scattering in a sodium nitrate aqueous solution

    Science.gov (United States)

    Ganot, Yuval; Bar, Ilana

    2015-09-01

    Frequency conversion of laser beams, based on stimulated Raman scattering (SRS) is an appealing technique for generating radiation at new wavelengths. Here, we investigated experimentally the SRS due to a single pass of a collimated frequency-doubled Nd:YAG laser beam (532 nm) through a saturated aqueous solution of sodium nitrate (NaNO3), filling a 50 cm long cell. These experiments resulted in simultaneous generation of 1st (564 nm) and 2nd (599 nm) Stokes beams, corresponding to the symmetric stretching mode of the nitrate ion, ?1(NO3-), with 40 and 12 mJ/pulse maximal converted energies, equivalent to 12% and 4% efficiencies, respectively, for a 340 mJ/pulse pump energy. The results indicate that the pump and SRS beams were thermally defocused and that four-wave mixing was responsible for the second order Stokes process onset.

  3. Polyion-counterion interactions in sodium carboxymethylcellulose-ethylene glycol-water ternary solutions.

    Science.gov (United States)

    Sharma, Ramesh; Das, Chanchal; Dahal, Sanjay; Das, Bijan

    2013-02-15

    Polyion-counterion interactions in sodium carboxymethylcellulose-ethylene glycol-water ternary system have been investigated with special reference to their variations with the polyelectrolyte concentration, the medium relative permittivity and the temperature using electrical conductance measurements. The experimental data have been analyzed on the basis of a model for semidilute polyelectrolyte conductivity which takes into account the scaling arguments proposed by Dobrynin et al. Concentration-dependent moderate counterion condensation (24-33%) was observed. Counterion condensation is found to be spontaneous which depends upon the EG-content of the medium and the temperature. A major proportion of the current is transported by the carboxymethylcellulose polyions. The results further demonstrated that the monomer units experience more frictional resistance in solution as the EG-content increases or as the temperature decreases. PMID:23399187

  4. Sodium carboxymethylcellulose-induced aggregation of 1-decyl-3-methylimidazolium chloride in aqueous solutions.

    Science.gov (United States)

    Ray, Dhiman; Das, Sourav; De, Ranjit; Das, Bijan

    2015-07-10

    Aggregation behavior of a surface active ionic liquid 1-decyl-3-methylimidazolium chloride (C10MeImCl) was studied in aqueous solutions in absence and in presence of sodium carboxymethylcellulose (NaCMC) by electrical conductivity, surface tension, vapor pressure, and fluorescence measurements. Ion-association behavior of C10MeImCl (aq) in the premicellar regime has also been investigated. Two characteristic concentrations, namely the critical aggregation concentration and polymer saturation concentration, before free C10MeImCl micelles appear in C10MeImCl-NaCMC solutions were identified. Effects of temperature, NaCMC concentration, and the bulk solution structural property on the self-aggregation of C10MeImCl have been discussed to elucidate C10MeImCl-NaCMC interactions. Thermodynamics of the micellization processes provided important insight regarding the (a) release of water molecules from the hydration layer around the hydrophilic domain, and from the water cage around the hydrophobic moiety of the SAIL, and (b) transfer of the hydrocarbon chains into the micelle and restoration of the H-bonding structure of the water around the micelle. PMID:25857982

  5. Influence of sodium carboxymethylcellulose on the aggregation behavior of aqueous 1-hexadecyl-3-methylimidazolium chloride solutions.

    Science.gov (United States)

    Das, Bijan; Ray, Dhiman; De, Ranjit

    2014-11-26

    The influence of sodium carboxymethylcellulose (NaCMC) on the aggregation phenomena of a surface active ionic liquid 1-hexadecyl-3-methylimidazolium chloride (C16MeImCl) was studied in aqueous solutions using electrical conductivity and surface tension measurements. The counterion condensation behavior of NaCMC (aq) and the premicellar ion-association behavior of C16MeImCl (aq) were also investigated. Two characteristic concentrations, namely the critical aggregation concentration and polymer saturation concentration, before free C16MeImCl micelles appear in C16MeImCl-NaCMC solutions have been identified. Effects of temperature, NaCMC concentration, and the charge density parameter of NaCMC on the self-aggregation of the C16MeImCl have been discussed to elucidate C16MeImCl-NaCMC interactions. The thermodynamic parameters for micellization of C16MeImCl were estimated both in absence and in the presence of NaCMC. The observed enthalpy-entropy compensation effect in C16MeImCl and C16MeImCl-NaCMC systems provided important insight as to how micellization processes are governed by the bulk structural property of the solution with respect to that of the water. PMID:25256477

  6. Stability of micafungin sodium solutions at different concentrations in glass bottles and syringes.

    Science.gov (United States)

    Briot, Thomas; Vrignaud, Sandy; Lagarce, Frédéric

    2015-08-15

    Micafungin is a costly treatment and packaging of 50 mg or 100 mg bottles only are available, while doses lower than 5 mg and 20 mg are often necessary in neonates and paediatrics patients, respectively. The stability of micafungin sodium in polypropylene syringes and glass bottles was studied at different concentrations. Solutions of micafungin diluted with NaCl 0.9% were prepared in glass bottles (20 and 10 mg/mL) or syringes (1 and 0.5 mg/mL) and stored at 25 °C, 60% humidity (RH), in the dark (ICH conditions). Solutions were also exposed to heat (70 °C) or alkaline solution (NaOH) in order to force degradation. Samples were analysed at days 1, 5, 8 (for bottles) and also 15 (for syringes) after the preparation and assayed in triplicate. Stability was studied using a stability-indicating high-performance liquid chromatographic method. Syringes stored at 25 °C retained over 90% of their initial concentration over the study period. Temperature and alkaline conditions had significant effect on the stability of micafungin, leading to apparition of degradation products. Moreover, sub visible particles were in the specification of the European Pharmacopeia along 15 days. To conclude, micafungin diluted in NaCl 0.9% and stored in polypropylene syringes was chemically stable for at least 15 days at 25 °C in the dark. PMID:26187166

  7. The study of LaNi5-type intermetallic compound behaviour in sodium borohydride alkaline solutions

    International Nuclear Information System (INIS)

    Behaviour of intermetallic LaNi4.5T0.5 compounds (IMC) (T=Mn, Cr, Co, Al, Fe, Cu) in alkaline solutions of sodium borohydride (0.1; 1.0; 4.0 mol/l of NaOH) is investigated within 293-318 K temperature interval. IMC (T=Mn, Al) hydrogenation reaction occurrence with the production of LaNi4.5T0.5H4.5 composition hydride phases is ascertained. Kinetics of the catalytic hydrolysis of NaBH4 in the above mentioned alkaline solutions in the presence of IMC is studied using the gas volumetric method. For all the IMC studied this reaction has a zero order by NaBH4 and the first one by the IMC. It is ascertained that a partial substitution of T for nickel in LaNi5 produces a notable effect on the NaBH4 hydrolysis rate. An anomalous increase of NaBH4 hydrolysis rate with the growth of solution alkalinity in the presence of IMC is detected. 11 refs.; 2 figs.; 3 tabs

  8. Experience and Solutions in the Decommissioning of Sodium Cooled Fast Reactors

    International Nuclear Information System (INIS)

    In a period of active employment of the new kind of energy — nuclear power — at various industrial plants, in technological processes, transportation units, in medicine, for R&D purposes, in the defence sphere, the problem of decommissioning the nuclear and radiation hazardous facilities (NRHF) has not been given adequate attention. To date, the problem has become a pressing challenge. According to predictions, by 2030, the decommissioning of 30 A-units is planned in the Russian Federation, as well as 13 defence reactors, more than 30 research reactors, several large enterprises of nuclear fuel cycle and open storage ponds for liquid radioactive wastes. A similar problem has to be resolved for the nuclear prototypes — the research and power reactors with fast neutron spectrum. The process of decommissioning the NRHF, in addition to financial problems to be resolved, necessitates a certain improvement in solutions in the administrative and legislative aspects, as well as on problems in science and technology. The latter are caused by sparse experience with the decommissioning of NRHF, great diversity of their engineering design solutions and physical characteristics, the lack of technologies needed, robotics, infrastructure for the dismantling of equipment with high radioactivity levels, conditioning of the radioactive wastes, reprocessing of spent nuclear fuel, and storage and final disposal of radioactive wastes. The two current approaches considered in the world for the management of the entire process of NRHF decommissioning, namely, that of delayed dismantling, and an option with immediate dismantling. For the time being, the Russian Federation has used the first of the approaches mentioned. The domestic and foreign experience, not extensive as it is, gained from the decommissioning of fast reactors with sodium (sodium-potassium) coolant has been highlighted in the report. (author)

  9. Sodium Chloride interaction with solvated and crystalline cellulose : sodium ion affects the tetramer and fibril in aqueous solution

    CERN Document Server

    Bellesia, Giovanni

    2013-01-01

    Inorganic salts are a natural component of biomass which have a significant effect on the product yields from a variety of biomass conversion processes. Understanding their effect on biomass at the microscopic level can help discover their mechanistic role. We present a study of the effect of aqueous sodium chloride (NaCl) on the largest component of biomass, cellulose, focused on the thermodynamic and structural effect of a sodium ion on the cellulose tetramer, and fibril. Replica exchange molecular dynamics simulations of a cellulose tetramer reveal a number of preferred cellulose-Na contacts and bridging positions. Large scale MD simulations on a model cellulose fibril find that Na+ perturbs the hydroxymethyl rotational state population and consequently disrupts the "native" hydrogen bonding network.

  10. Effect of bicarbonate on biodegradation behaviour of pure magnesium in a simulated body fluid

    International Nuclear Information System (INIS)

    The effect of bicarbonate on biodegradation of pure magnesium in a simulated body fluid is investigated by means of X-ray diffraction, X-ray photoelectron spectroscopy, polarization curve and electrochemical impedance spectroscopy. The results show that magnesium biodegrades rapidly and non-uniformly during 27 h of immersion in four simulated body fluid solutions containing different concentrations of bicarbonate. The biodegradation rate first decreases and then increases with time. A small amount of bicarbonate in simulated body fluid has an inhibition effect on the Mg dissolution, while an overdose of bicarbonate addition activates the magnesium surface in the simulated body fluid. The interesting phenomena can be interpreted by a surface film model involving precipitation of calcium carbonate and further ionization of bicarbonate in the simulated body fluids, incorporation of calcium, carbonate and phosphate compounds in the surface film, and development of chloride-induced pitting corrosion damage on the magnesium with time

  11. Augmentation and ionic mechanism of effect of beta-N-methylamino-L-alanine in presence of bicarbonate on membrane potential of Retzius nerve cells of the leech Haemopis sanguisuga.

    Science.gov (United States)

    Lopicic, Srdjan; Nedeljkov, Vladimir; Cemerikic, Dusan

    2009-07-01

    The role of neurotoxic non-protein amino acid beta-N-methylamino-L-alanine (L-BMAA) as a putative causative agent of Western pacific amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC) has recently been reinvigorated. In view of this data we have investigated the strength and mechanism of effect of L-BMAA in presence of 20 mmol/L bicarbonate (a cofactor for BMAA) on membrane potential of the Leech Haemopis sanguisuga. Our results show that L-BMAA has excitatory effect in bicarbonate containing solution, which is more potent than in nominally bicarbonate free solution. This potentiation by bicarbonate is L-BMAA specific, as it was not exhibited by beta-N-oxalylamino-L-alanine. The effect of L-BMAA was partially blocked by non-NMDA receptor antagonist CNQX. Application of L-BMAA caused a decrease in input membrane resistance, an increase of intracellular sodium activity, and a decrease of intracellular potassium activity. Present findings indicate that BMAA could initiate excitotoxicity through activation of non-NMDA ionotropic glutamate receptors. PMID:19272457

  12. Effect of different ions on the anodic behaviour of alloy 800 chloride solutions at high temperature

    International Nuclear Information System (INIS)

    The anodic behaviour and passivity breakdown of alloy 800 in sodium bicarbonate and sodium phosphate aqueous solutions were studied in the temperature range from 100 degrees C to 280 degrees C by means of electrochemical techniques. The effect of phosphate or bicarbonate additions on the pitting susceptibility and pitting morphology of the alloy in chloride solutions was also examined. Experiments were performed in the following solutions: 0.1M NaHCO3, at 100 degrees C, 200 degrees C, 280 degrees C; 0.06M NaH2PO4 + 0.04M Na2HPO4, at 100 degrees C, 200 degrees C and 280 degrees C, and 0.1M NaCl with different additions of bicarbonate ion (0.02M, 0.05M and 0.1M) and phosphate ion (0.01M, 0.05M and 0.1M) at 100 degrees C and 280 degrees C. The anodic polarization curves of alloy 800 in deaerated 0.1M NaHCO3 and 0.06M NaH2PO4 + 0.04M Na2HPO4 solutions exhibited a similar shape at all the tested temperatures. No localized or generalized corrosion was detected on the metallic surface after polarization. The results obtained in chloride plus bicarbonate and chloride plus phosphate mixtures showed that the pitting potential of alloy 800 in chloride solutions was increased by the presence of bicarbonate or phosphate ions. In those solutions where the inhibitor concentration in the mixture is equal or higher than the chloride concentration , the behaviour of the alloy is similar to the one observed in the absence of chlorides. Changes in pitting morphology were found in phosphate containing solutions, while the pits found in bicarbonate containing solutions were similar to those formed in pure chloride solutions. (author). 3 refs., 4 figs

  13. Utilização de Resíduos Gerados por Indústria do Setor Sucroalcoleiro, Pela RAUDI Indústria e Comércio LTDA, na Produção de Bicarbonato de Sódio. = Use of Residues Generated for the Sugar-Alcohol Industry Sector, by The RAUDI Industry and Commerce Limited, in the Sodium Bicarbonate Production.

    Directory of Open Access Journals (Sweden)

    Frederico F. da Silva

    2008-07-01

    Full Text Available A consciência ecológica está intimamente ligada à preservação do meio ambiente. A importância da preservação dos recursos naturais passou a ser preocupação mundial e nenhum país pode eximir-se de sua responsabilidade. Essa necessidade de proteção do ambiente é antiga e surgiu quando o homem passou a valorizar a natureza, mas não de maneira tão acentuada como nos dias de hoje. Esse trabalho tem como objetivo, passar ao leitor como é possível a utilização de resíduos na obtenção de novos produtos ecologicamente corretos, como o uso de resíduos poluentes de uma usina de álcool transformando-os em matéria prima no processo de fabricação do bicarbonato de sódio. = The ecological conscience is intimately linked to the preservation of the environment. The importance of the preservation of the natural resources became a world-wide concern and no country can be exempted of its responsibility. This necessity of protection of the environment is not a new thing and appeared when man started to value nature, but not in an accentuated way as nowadays. This work has as objective, to inform the reader as to the use of residues in the attainment of new ecologically correct products possible, as the use of pollutant residues of an alcohol plant transforming them into substance in the process of manufacturing sodium bicarbonate.

  14. Direct AFM force measurements between air bubbles in aqueous monodisperse sodium poly(styrene sulfonate) solutions.

    Science.gov (United States)

    Browne, Christine; Tabor, Rico F; Grieser, Franz; Dagastine, Raymond R

    2015-08-01

    Structural forces play an important role in the rheology, processing and stability of colloidal systems and complex fluids, with polyelectrolytes representing a key class of structuring colloids. Here, we explore the interactions between soft colloids, in the form of air bubbles, in solutions of monodisperse sodium poly(styrene sulfonate) as a model polyelectrolyte. It is found that by self-consistently modelling the force oscillations due to structuring of the polymer chains along with deformation of the bubbles, it is possible to precisely predict the interaction potential between approaching bubbles. In line with polyelectrolyte scaling theory, two distinct regimes of behaviour are seen, corresponding to dilute and semi-dilute polymer solutions. It is also seen that by blending monodisperse systems to give a bidisperse sample, the interaction forces between soft colloids can be controlled with a high degree of precision. At increasing bubble collision velocity, it is revealed that hydrodynamic flow overwhelms oscillatory structural interactions, showing the important disparity between equilibrium behaviour and dynamic interactions. PMID:25881266

  15. Fracture of nickel-titanium superelastic alloy in sodium hypochlorite solution

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Ken' ichi; Kaneko, Kazuyuki; Yabuta, Eiji; Asaoka, Kenzo; Sakai, Jun' ichi

    2004-03-25

    Fracture of the Ni-Ti superelastic alloy for endodontic instruments such as files was investigated with a sustained tensile-loading test in sodium hypochlorite (NaOCl) solution of various concentrations. It was found that the time to fracture was reduced when the applied stress exceeded the critical stress for martensite transformation. When the applied stress was higher than the critical stress, the 0.3 mm diameter wires of the Ni-Ti superelastic alloy sometimes fractured within 60 min. From the results of observations of the fracture surface using a scanning electron microscope, it was revealed that the fracture of the Ni-Ti superelastic alloy is significantly influenced by corrosion when the applied stress was higher than the critical stress for martensite transformation. The results of the present study suggest that one of the causes of the fracture of Ni-Ti files during clinical use is corrosion under the applied stress above the critical stress for martensite transformation in NaOCl solution.

  16. Analysis of antibacterial efficacy of plasma-treated sodium chloride solutions

    Science.gov (United States)

    Hänsch, Mareike A. C.; Mann, Miriam; Weltmann, Klaus-Dieter; von Woedtke, Thomas

    2015-11-01

    In this study, the change of chemical composition of sodium chloride solutions (NaCl, 0.85%) induced by non-thermal atmospheric pressure plasma (APP) treatment and subsequent effects on bacteria (Escherichia coli) are investigated. Besides acidification caused by APP, hydrogen peroxide (H2O2), nitrite (\\text{NO}2- ), and nitrate (\\text{NO}3- ) are generated as stable end-products of various chemical reactions in APP-treated liquids. Inactivation kinetics and reduction factors were recorded for E. coli (K12). Almost identical antimicrobial effects were observed with both direct APP exposure to bacteria suspension and exposure of APP-treated liquids to bacteria (indirect treatment). Consequently, main bactericidal effects are caused by chemical reactions which are mediated via the liquid phase. Moreover, APP-treated liquids have shown long-term activity (30?min) that possibly correlates with the ratio of \\text{NO}2- /H2O2. Therefore, \\text{NO}2- and H2O2 are identified as key agents for antimicrobial short- and long-term effects, respectively. The antimicrobial stability observed is strongly dependent on the used treatment regime and correlates additionally with the altered chemical composition of APP-treated liquids. Besides these effects, it was also shown that bacteria do not acquire resistance to such APP-treated solutions.

  17. A comparison study between sodium dodecyl sulfate and sodium dodecyl sulfonate with respect to the thermodynamic properties, micellization, and interaction with poly(ethylene glycol) in aqueous solutions

    International Nuclear Information System (INIS)

    Graphical abstract: Apparent molar volume against molality: o, ·, and ?, respectively in water, (1 and 4) wt% PEG solution at 293.15 K; x, ?, and lozenge, respectively in water, (1 and 4) wt% PEG solution at 313.15 K. Research highlights: ? C12H25SO3Na(SDSn) was seen to interact with PEG more weakly than C12H25SO4Na(SDS). ? The constraints on molecular mobility of SDS micelles are larger than those of SDSn. ? Entropy change on micellization for SDSn is larger than those for SDS. ? Micelle formation of SDS is less endothermic and more spontaneous than that of SDSn. ? Micelles of SDS have smaller aggregation number than that of SDSn. - Abstract: The density, sound velocity, and conductivity measurements were performed on aqueous solutions of sodium dodecyl sulfate (C12H25SO4Na) or sodium dodecyl sulfonate (C12H25SO3Na) in the absence and presence of poly(ethylene glycol) (PEG) at different temperatures. Changes in the apparent molar volumes and isentropic compressibilities upon micellization were derived using a pseudophase-transition approach and the infinite dilution apparent molar properties of the monomer and micellar form of C12H25SO4Na and C12H25SO3Na were determined. Variations of the critical micelle concentrations (CMCs) of both surfactants in the solutions investigated with temperature were obtained from which thermodynamic parameters of micellization were estimated. It was found that at low temperature the micelle formation process is endothermic and therefore, this process must be entropically driven. However, upon increasing the temperature, the enthalpic factor becomes more significant and, at temperatures higher than 303.15 K the micellization is enthalpy driven. The interactions between C12H25SO4Na/C12H25SO3Na and PEG were studied and it was found that sodium alkyl sulfonates were seen to interact more weakly than their sulfate analogues.

  18. A Fiber-Optic Sensor Using an Aqueous Solution of Sodium Chloride to Measure Temperature and Water Level Simultaneously

    OpenAIRE

    Wook Jae Yoo; Hyeok In Sim; Sang Hun Shin; Kyoung Won Jang; Seunghyun Cho; Joo Hyun Moon; Bongsoo Lee

    2014-01-01

    A fiber-optic sensor system using a multiplexed array of sensing probes based on an aqueous solution of sodium chloride (NaCl solution) and an optical time-domain reflectometer (OTDR) for simultaneous measurement of temperature and water level is proposed. By changing the temperature, the refractive index of the NaCl solution is varied and Fresnel reflection arising at the interface between the distal end of optical fiber and the NaCl solution is then also changed. We measured the modified ...

  19. Bicarbonate attenuates arterial desaturation during maximal exercise in humans

    DEFF Research Database (Denmark)

    Nielsen, Henning B; Bredmose, Per P; Strømstad, Morten; Volianitis, Stefanos; Quistorff, Bjørn; Secher, Niels H

    2002-01-01

    The contribution of pH to exercise-induced arterial O2 desaturation was evaluated by intravenous infusion of sodium bicarbonate (Bic, 1 M; 200-350 ml) or an equal volume of saline (Sal; 1 M) at a constant infusion rate during a "2,000-m" maximal ergometer row in five male oarsmen. Blood-gas variables were corrected to the increase in blood temperature from 36.5 +/- 0.3 to 38.9 +/- 0.1 degrees C (P < 0.05; means +/- SE), which was established in a pilot study. During Sal exercise, pH decreased fr...

  20. Antimicrobial activity of complete denture cleanser solutions based on sodium hypochlorite and Ricinus communis - a randomized clinical study.

    Science.gov (United States)

    Salles, Marcela Moreira; Badaró, Maurício Malheiros; Arruda, Carolina Noronha Ferraz de; Leite, Vanessa Maria Fagundes; Silva, Cláudia Helena Lovato da; Watanabe, Evandro; Oliveira, Viviane de Cássia; Paranhos, Helena de Freitas Oliveira

    2015-12-01

    To preserve oral health and to maintain the prosthetic devices, it is important not only to improve the properties of commonly known hygiene products, but also to investigate new materials with antimicrobial action. Objectives This study evaluated the antimicrobial activity of sodium hypochlorite (0.25% and 0.50%) and 10% Ricinus communis' solutions against specific microorganisms. Material and Methods Sixty four maxillary complete denture wearers were instructed to brush their dentures three times a day and to soak them (20 min/day) in the solutions: SH1: 0.25% sodium hypochlorite; SH2: 0.5% sodium hypochlorite; RC: 10% R. communis oil; and C: 0.85% saline (control). The solutions were used for 7 days in a randomized sequence. Following each period of use, there was a 1-week washout period. Antimicrobial activity was determined by Colony Forming Units (CFU) counts of Streptococcus mutans, Candida spp., and gram-negative microorganisms. For collecting biofilm, the internal surface of maxillary dentures was brushed with saline solution, and biofilm suspension obtained. After dilutions (100 - 10-3), aliquots were seeded in Mitis salivarius, CHROMagar Candida®, and MacConkey agar for detecting S. mutans, Candida spp., or gram-negative microorganisms, respectively. After incubation, colonies were counted, and CFU/mL values were calculated. Then, transformation - log10 (CFU+1) - data were analyzed using the Friedman test (α=0.05). Results showed significant differences between the solutions (pCandida spp., RC and SH1 solutions showed similar effect while SH2 showed superior activity. SH1 and SH2 solutions showed antimicrobial action against gram-negative microorganisms. The Candida species most frequently isolated was C. albicans, followed by C. tropicalis and C. glabrata. Conclusions The 0.5% sodium hypochlorite solution was the most effective and might be used to control denture biofilm. C. albicans was the most frequently isolated Candida sp. PMID:26814466

  1. Electrochemical research on corrosion behavior of A3 steel in compound sodium molybadate and organic inhibitor solution

    Science.gov (United States)

    Sun, C. X.; Chen, Y. M.; Xu, H. W.; Zhang, M.; Chen, M.; Xue, M.; Wu, J. Y.; Huang, C. S.

    2015-07-01

    The electrochemical corrosion behavior of A3 in compound sodium molybdate and organic inhibitor solution was tested by the electrochemical workstation method. The concentration of the compound inhibitor set to range 250 mg/L to 3000 mg/L. The polarization curve results of A3 in different concentration inhibitor solutions show that the inhibitor markedly represses the anodic processes. The EIS has two time constant. The extreme concentration is 1500 mg/L.

  2. Techniques for extinguishing sodium fires

    International Nuclear Information System (INIS)

    The experimental work done to evaluate the performance of commercially available fire extinguishants and powders for sodium fires is described. Dry chemical powder with sodium bicarbonate base was found very effective. Another effective method of extinghishing fire by using perforated covered tray is also discussed. (auth.)

  3. Efeito alcalinizante de soluções eletrolíticas intravenosas com concentrações elevadas de lactato de sódio infundidas em bezerros sadios / Alkalinizing effect of intravenous electrolyte solutions with high sodium lactate concentrations infused in healthy calves

    Scientific Electronic Library Online (English)

    J.R.C., Junqueira; M.R.S., Balarin; K.K.M.C., Flaiban; D.S., Barbosa; J.A.N., Lisboa.

    2015-02-01

    Full Text Available Com o objetivo de investigar o potencial alcalinizante de soluções eletrolíticas com concentrações elevadas de lactato de sódio em bezerros sadios, foram idealizadas seis soluções contendo 28, 56 e 84mEq/L de lactato (L28, L56 e L84) ou de bicarbonato (B28, B56 e B84), com concentrações de sódio, de [...] potássio e de cálcio semelhantes às da solução de Ringer com lactato (SRL). As soluções contendo bicarbonato de sódio foram utilizadas como padrão para comparação. Seis bezerros receberam, por via intravenosa, todas as seis soluções, uma a cada vez, com intervalo de quatro a cinco dias entre as infusões, em volume correspondente a 10% do peso corporal, durante cinco horas (20mL/kg/h). Amostras de sangue venoso e de urina foram coletadas antes de iniciar a infusão, na metade do volume, ao término e duas horas e meia após o término da infusão. Determinaram-se concentração de proteína plasmática total, pH sanguíneo e urinário, pCO2, HCO3 -, BE, concentração plasmática e urinária de lactato L e concentrações séricas e urinárias de Na+, K+, Cl- e creatinina. A solução L28, idêntica à SRL, provocou discreto incremento da reserva alcalina e, consequentemente, produziu efeito alcalinizante insuficiente para a correção de estados de acidose metabólica. A solução L84, além de provar-se segura, provocou o maior aumento da reserva alcalina, equivalente à B84, e, assim, produziu efeito capaz de corrigir o grau moderado de acidose metabólica. Abstract in english The alkalinizing effects of electrolyte solutions with high concentration of sodium lactate were evaluated in healthy calves. Six solutions were formulated containing 28, 56 and 84mEq/L of lactate (L28, L56 and L84) or bicarbonate (B28, B56 and B84), and sodium, potassium and calcium concentrations [...] similar to the lactated Ringer's solution (LRS). The solutions containing sodium bicarbonate were used as a standard for comparison. Six calves received all six solutions intravenously, one at a time, with an interval of four to five days between the infusions, in a volume corresponding to 10% of body weight, during five hours (20mL/kg/h). Venous blood and urine samples were taken prior to the beginning of the infusion, at a half volume, at the end and two and a half hours after the end of the infusion. Total plasma protein concentration, urinary and blood pH, blood pCO2, HCO3 - and BE, plasma and urine L lactate concentration and serum and urine Na+, K+, Cl- and creatinine concentrations were measured. The L28 solution, equal to LRS, caused a slight increase in the alkaline reserve, producing an alkalinizing effect insufficient for correction of metabolic acidosis states. The L84 solution was safe and produced the greater increase in the alkaline reserve, equivalent to B84 solution, and suitable for correcting a moderate degree of metabolic acidosis.

  4. Crystallochemical aspects of thermodynamic prehistory effect on the type of temperature-composition phase diagrams for sodium niobate-lithium and sodium niobate-potassium solid solutions

    International Nuclear Information System (INIS)

    One compared composition (x)-temperature (T) phase diagrams of crystals derived for the first time with the available x-T-diagrams of ceramics of sodium niobate-lithium (I) and sodium niobate-potassium (II) ferroelectric solid solutions that was prepared following various routes (standard burning, hot pressing). It was determined that in I system thermodynamic history (in particular, production conditions) affected substantially type of phase x-T-diagrams within the whole range of the perovskite phase stability, while in II system the mentioned effect manifested itself most essentially at low content of potassium (x ? 0.15). The obtained results are related with low values of t tolerance factor for compositions of solid solutions properties of which are critical as to thermodynamic history. Low (? 0.9-0.93) values of t show the porosity of structure of compositions within the mentioned concentration range of I and II systems responsible for occurrence of rather equitable competing structure instabilities (polar and rotation ones), as well as, possibility of coexistence of substitutional and interstitial solid solutions

  5. Textures on the surface of BSA films with different concentrations of sodium halides and water state in solution

    Science.gov (United States)

    Glibitskiy, Gennadiy; Glibitskiy, Dmitriy; Gorobchenko, Olga; Nikolov, Oleg; Roshal, Alexander; Semenov, Mikhail; Gasan, Anatoliy

    2015-03-01

    The formation of the textures on the surface of the films from the solutions of bovine serum albumin (BSA) with sodium halides (NaF, NaCl, and NaBr) of various concentrations was studied. The formation of symmetric zigzag textures on the surface of BSA films (Cryst Eng 3:173-194, 2000) in the presence of sodium halides depends on the conformational state of the protein globule. Thermal denaturation of BSA also did not allow to form zigzag textures on the surface of the films.

  6. Decreasing Molybdenum Content in U3O8 of Bandar Abbas Uranium Plant by Stripping, Acidic Sodium Chloride Solution

    International Nuclear Information System (INIS)

    Molybdenum content in U3O8 is one of the difficulties in uranium oxide production plant, as contaminant. Several methods have been proposed for reducing Molybdenum from U3O8 process circuit. As a few changes in the process circuit of Bandar Abbas Uranium Plant were aimed, the loaded organic solvent containing uranium and molybdenum were stripped with acidic sodium chloride solution. The current 10% Sodium carbonate solution was substituted by 1.2 M NaCl + 0.02 M H2SO4 as a new strip solution. This method decreases Mo contents from 96.94 to 4.17 percent. With the proceeding precipitation and the calcination stages, the Molybdenum amounts in U3O8 was reduced from 6.4 to 0.14 percent.

  7. Are micelles needed to form methane hydrates in sodium dodecyl sulfate solutions?

    Science.gov (United States)

    Albertí, M; Costantini, A; Laganá, A; Pirani, F

    2012-04-12

    The possibility that methane hydrates form in sodium dodecyl sulfate (SDS) water solutions without the help of micelles formation has been investigated. To asses whether micelles are needed for the hydrate to form only one SDS molecule has been considered. To figure out the possible mechanism through which the SDS promotes the formation of methane clathrate the dynamics of CH(4) solvation in the presence and absence of the surfactant molecule is monitored. To carry out the dynamical calculations, the SDS-H(2)O, SDS-CH(4), and CH(4)-H(2)O interactions were described using a recently proposed model potential. The adopted model leverages both on the decomposition of the molecular polarizability in effective components associated with the interaction centers distributed on the molecular frame and on the use of an improved Lennard-Jones functional form to represent the effective pair interaction energies. Molecular dynamics simulations performed on such potential, contrary to some earlier assumptions, do not support mechanisms requiring the formation of micelles as suggested by the findings of more recent experiments. PMID:22448641

  8. Kinetics and mechanism of sphalerite leaching by sodium nitrate in sulphuric acid solution

    Directory of Open Access Journals (Sweden)

    Soki? M.

    2012-01-01

    Full Text Available Interest for application of hydrometallurgical processes in a processing of complex sulphide ores and concentrates has increased in recent years. Their application provides better metal recoveries and reduced emission of gaseous and toxic ageneses in the environment. The kinetics and mechanism of sphalerite leaching from complex sulphide concentrate with sulphuric acid and sodium nitrate solution at standard conditions was presented in this paper. The influences of temperature and time on the leaching degree of zinc were investigated and kinetic analysis of the process was accomplished. With temperature increasing from 60 to 90°C, the zinc leaching increased from 25.23% to 71.66% after 2 hours, i.e. from 59.40% to 99.83% after 4 hours. The selected kinetic model indicated that the diffusion through the product layer was the rate-controlling step during the sphalerite leaching. The activation energy was determined to be 55 kJ/mol in the temperature range 60-90°C. XRD, light microscopy and SEM/EDX analyses of the complex concentrate and leach residue confirmed formation of elemental sulphur and diffusion-controlled leaching mechanism.

  9. Passivation of chalcopyrite during the leaching with sulphuric acid solution in presence of sodium nitrate

    Directory of Open Access Journals (Sweden)

    Soki? Miroslav D.

    2010-01-01

    Full Text Available In this work, the process of the chalcopyrite leaching in sulphuric acid solution was investigated. Sodium nitrate was used as oxidant in the leaching process. Chemical reactions of leaching and their thermodynamic possibilities are predicted based on the calculated Gibbs energies and analysis of E?pH diagrams. The negative values of the Gibbs energy show that all chemical reactions are thermodynamically feasible at atmospheric pressure and in a temperature range 25-90°C. At high electrode potential and low pH values, Cu2+, Fe2+ and Fe3+ ions exist in water solutions. The increase of temperature reduces the probability of Fe3+ ion existence in the system. The chalcopyrite concentrate, enriched in the “Rudnik” flotation plant, with 27.08% Cu, 25.12% Fe, 4.15% Zn and 2.28% Pb was used in the work. XRD and DTA analysis of the concentrate reveals that the sample contains mainly the chalcopyrite with small amount of sphalerite. For the description of the reaction of leaching process the leach residuals, obtained at different conditions, were chosen for XRD, TG/DTA and SEM/EDX analyses. The elemental sulphur and chalcopyrite phases identified in leach residuals confirm our prediction that the elemental sulphur is formed during the leaching process. Accordingly, elemental sulphur is the main product of the reaction, while a minor amount of sulphide sulphur is oxidized to sulphate during the leaching. The sulphur formed during the reaction was precipitated at the particle surfaces, and slowed down the leaching rate in the final stage of leaching process. In the initial stage, the reaction rate was controlled by the surface reaction. The mechanism, latter has been changed into a diffusion controlled one.

  10. tlpA gene expression is required for arginine and bicarbonate chemotaxis in Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Oscar A Cerda

    2011-01-01

    Full Text Available About half of the human population is infected with Helicobacter pylori, a bacterium causing gastritis, peptic ulcer and progression to gastric cancer. Chemotaxis and flagellar motility are required for colonization and persistence of H. pylori in the gastric mucus layer. It is not completely clear which chemical gradients are used by H. pylori to maintain its position. TlpA, a chemotaxis receptor for arginine/ bicarbonate, has been identified. This study aimed to find out whether tlpA gene expression is required for the chemotactic response to arginine/bicarbonate. Wild-type motile H. pylori ATCC 700392 and H. pylori ATCC 43504, a strain having an interrupted tlpA gene, were used. Also, a tlpA-knockout mutant of H. pylori 700392 (H. pylori 700-tlpA::cat was produced by homologous recombination. Expression of tlpA was assessed by a Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR assay. Chemotaxis was measured as a Relative Chemotaxis Response (RCR by a modified capillary assay. H. pylori 700392 presented chemotaxis to arginine and sodium bicarbonate. H. pylori 700-tlpA::cat showed neither tlpA gene expression nor chemotaxis towards arginine and bicarbonate. Besides confirming that TlpA is a chemotactic receptor for arginine/bicarbonate in H. pylori, this study showed that tlpA gene expression is required for arginine/bicarbonate chemotaxis.

  11. Is bicarbonate stable in and on the calcite surface?

    Science.gov (United States)

    Andersson, M. P.; Rodriguez-Blanco, J. D.; Stipp, S. L. S.

    2016-03-01

    We have used density functional theory with the COSMO-RS implicit solvent model to predict the pKa for the deprotonation of bicarbonate to carbonate, i.e. HCO3- CO32- + H+, when HCO3- is included in, and adsorbed on, a calcite surface. We have used cluster models (80-100 atoms) to represent the flat {10.4} surface, acute steps, obtuse steps, two types of kinks on the acute step and two types of kinks on the obtuse steps. Based on the predicted pKa values, which range from -6.0 to 2.4 depending on the surface site, we conclude that bicarbonate deprotonates to carbonate when it is in calcite even when pH in solution is very low. This is true for all surface sites, even for solutions where 2.4 H2CO30 is the dominant dissolved species. When bicarbonate is adsorbed on calcite, the predicted pKa for deprotonation is 7.5, which is ?3 pH units lower than in aqueous solution, 10.35. This means that adsorbed carbonate is stable even when the concentration of dissolved CO32- is several orders of magnitude lower. This has a significant effect on surface charge and thus the behaviour of the calcite surface. Our results help explain the potential determining behaviour of the carbonate species in calcite-water systems, particularly in the pH range where the bicarbonate species dominates in water and where the carbonate species dominates at the surface, i.e. when 7.5 < pH < 10.35. Our atomic scale data for the various calcite surface sites provide the needed input to improve and constrain surface complexation modelling and are especially useful for predicting behaviour in systems where experiments are difficult or impossible, such as at high temperature and pressure.

  12. Comparison of liquid metal solution model predictions with compatibility data of niobium with liquid sodium

    International Nuclear Information System (INIS)

    Highlights: • The activity coefficient of niobium in ternary melt can be obtained by means of integrating the Gibbs–Duhem equation. • Effect of oxygen on niobium saturation concentration in sodium is more pronounced at low temperatures. • At the initial stage of the process of interaction niobium with sodium containing oxygen, a decisive role is played by the mechanism, based on the significant increase of solubility of niobium in sodium. - Abstract: Theoretical correlations based on the coordination cluster model have been used to obtain the solubility of niobium in liquid sodium as a function of oxygen content. It is shown that the derived equations are useful to provide understanding of a relationship between thermodynamic properties and local ordering in the Na–Nb–O melt. The effect of oxygen in sodium on the compatibility niobium with liquid sodium is discussed in terms of two processes: (1) oxygen level increases the solubility of niobium in liquid sodium, and (2) oxygen enhanced dissolution by liquid sodium has been explained by taking into account the formation of ternary oxide of the alkali metal and niobium

  13. Comparison of liquid metal solution model predictions with compatibility data of niobium with liquid sodium

    Energy Technology Data Exchange (ETDEWEB)

    Krasin, V.P., E-mail: vkrasin@rambler.ru; Soyustova, S.I.

    2014-08-01

    Highlights: • The activity coefficient of niobium in ternary melt can be obtained by means of integrating the Gibbs–Duhem equation. • Effect of oxygen on niobium saturation concentration in sodium is more pronounced at low temperatures. • At the initial stage of the process of interaction niobium with sodium containing oxygen, a decisive role is played by the mechanism, based on the significant increase of solubility of niobium in sodium. - Abstract: Theoretical correlations based on the coordination cluster model have been used to obtain the solubility of niobium in liquid sodium as a function of oxygen content. It is shown that the derived equations are useful to provide understanding of a relationship between thermodynamic properties and local ordering in the Na–Nb–O melt. The effect of oxygen in sodium on the compatibility niobium with liquid sodium is discussed in terms of two processes: (1) oxygen level increases the solubility of niobium in liquid sodium, and (2) oxygen enhanced dissolution by liquid sodium has been explained by taking into account the formation of ternary oxide of the alkali metal and niobium.

  14. Effect of temperature on solvation behaviour of diclofenac sodium salt in aqueous glycine and L-proline solutions

    International Nuclear Information System (INIS)

    Highlights: • Solvation behaviour of diclofenac drug studied in aqueous solutions. • Density and speed of sound of drug in aq. glycine and L-proline are measured. • Hydrophobic nature of diclofenac sodium salt is studied. • Effect of temperature on solvation of diclofenac sodium salt is analysed. - Abstract: Apparent molar volume (V2,?) and apparent molar isentropic compressibility (Ks,2,?) of diclofenac sodium salt (DSS) drug within the concentration range of (0.001 to 0.008) mol · kg?1 in (0.01, 0.03 and 0.05) mol · kg?1 aqueous glycine and L-proline solutions are computed from the experimental density (?) and speed of sound (u) values at T = (293.15 to 313.15) K and atmospheric pressure. Derived parameters such as partial molar properties, transfer partial molar properties, hydration numbers and Hepler’s constant are computed from the data of V2,? and Ks,2,?. These parameters have been used to understand the effect of temperature on interactions between DSS drug and aqueous glycine/L-proline solution. Furthermore, the structure making and breaking ability of DSS drug in probed solutions are analysed at experimental conditions

  15. Efeito de bicarbonato de sódio, feno e bagaço "in natura" sobre a digestibilidade e o desempenho de zebuínos em crescimento alimentados com bagaço de cana auto-hidrolisado / Effect of sodium bicarbonate, grass hay und untreated bagasse on the performance of growing zebu cattle fed steam treated sugarcane bagasse

    Scientific Electronic Library Online (English)

    D.P.D., Lanna; C., Boin.

    Full Text Available O bagaço de cana-de-açúcar "in natura" (BIN) associado ou não ao bicarbonato de sódio foi testado como substituto do feno de gramínea como fonte de fibra longa para rações de ruminantes balanceadas com altas proporções de bagaço auto-hidrolisado (BAH). A ração básica (I) continha 54% BAH; 10% milho [...] grão; 25% farelo de algodão; 8% feno de gramínea; 0,9% calcáreo; 0,5% uréia; e 1,5% premix mineral, base seca. As rações II e III continham BIN e BIN mais bicarbonato de sódio (1,1%, base seca) respectivamente em substituição ao feno de gramínea da ração I. Foram usados bovinos Nelore machos não castrados e fêmeas (18 de cada sexo) em crescimento com médias iniciais de peso vivo e idade de 199 kg e 11 meses. O delineamento estatístico usado foi um fatorial com 3 rações e dois sexos, com dois animais por parcela. O período de adaptação foi de 15 dias e o experimental de 87 dias. Os dados para GPV (kg/dia); ingestão de MS (% PV); conversão alimentar (kg MS/Kg GPV); e pH fecal foram de: 0,909; 2,79; 7,41; e 6,46 para a ração I; 0,867; 2,65; 7,24; e 6,57 para a ração II; e 1,019; 2,88; 7,03 e 6,73 para a ração III. A ração III foi superior rações I e II para ganho de peso (P Abstract in english Crude sugarcane bagasse (BIN) with and without the addition of sodium bicarbonate was evaluated as a substitute for grass hay as source of long fiber in ruminant diets balanced with high proportions of steam pressure treated sugarcane bagasse (BAH, 17kgf/cm² for 6 minutes). The basal ration (I) had [...] 54% BAH; 10% corn grain; 25% cottonseed meal; 8% grass hay, 0.9% limestone; 0.5% urea; and 1.5% mineral premix, dry basis. In rations II and III, grass hay was replaced by BIN and BIN plus sodium bicarbonate (1.1%, dry basis) respectively. Nelore bull and heifer calves (18 animals each sex) with 199kg average weight and 11 months average age were used in a factorial design (3 rations and 2 sexes), with two animals per plot. The adaptation and experimental periods were 15 and 87 days respectively. The results for LWG (kg/day), DM intake (% LW), DM conversion (kg DM/kg LWG), and fecal pH were: 0.909; 2.79; 7.41 and 6.46 for ration I; 0.867; 2.65; 7.24; and 6.57 for ration II; and 1.019; 2.88; 7.03 and 6.75 for ration III respectively. Ration III was superior to rations I and II for LWG (P

  16. 21 CFR 184.1721 - Sodium acetate.

    Science.gov (United States)

    2010-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  17. A comparison study between sodium dodecyl sulfate and sodium dodecyl sulfonate with respect to the thermodynamic properties, micellization, and interaction with poly(ethylene glycol) in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Rahmat, E-mail: rsadeghi@uok.ac.ir [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Shahabi, Somayyeh [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2011-09-15

    Graphical abstract: Apparent molar volume against molality: o, {center_dot}, and {Delta}, respectively in water, (1 and 4) wt% PEG solution at 293.15 K; x, {Delta}, and lozenge, respectively in water, (1 and 4) wt% PEG solution at 313.15 K. Research Highlights: > C{sub 12}H{sub 25}SO{sub 3}Na(SDSn) was seen to interact with PEG more weakly than C{sub 12}H{sub 25}SO{sub 4}Na(SDS). > The constraints on molecular mobility of SDS micelles are larger than those of SDSn. > Entropy change on micellization for SDSn is larger than those for SDS. > Micelle formation of SDS is less endothermic and more spontaneous than that of SDSn. > Micelles of SDS have smaller aggregation number than that of SDSn. - Abstract: The density, sound velocity, and conductivity measurements were performed on aqueous solutions of sodium dodecyl sulfate (C{sub 12}H{sub 25}SO{sub 4}Na) or sodium dodecyl sulfonate (C{sub 12}H{sub 25}SO{sub 3}Na) in the absence and presence of poly(ethylene glycol) (PEG) at different temperatures. Changes in the apparent molar volumes and isentropic compressibilities upon micellization were derived using a pseudophase-transition approach and the infinite dilution apparent molar properties of the monomer and micellar form of C{sub 12}H{sub 25}SO{sub 4}Na and C{sub 12}H{sub 25}SO{sub 3}Na were determined. Variations of the critical micelle concentrations (CMCs) of both surfactants in the solutions investigated with temperature were obtained from which thermodynamic parameters of micellization were estimated. It was found that at low temperature the micelle formation process is endothermic and therefore, this process must be entropically driven. However, upon increasing the temperature, the enthalpic factor becomes more significant and, at temperatures higher than 303.15 K the micellization is enthalpy driven. The interactions between C{sub 12}H{sub 25}SO{sub 4}Na/C{sub 12}H{sub 25}SO{sub 3}Na and PEG were studied and it was found that sodium alkyl sulfonates were seen to interact more weakly than their sulfate analogues.

  18. Radiostrontium separation from sodium molybdate solution and its measurement using LSA. An application to radiopharmaceutical analysis

    International Nuclear Information System (INIS)

    Technetium (99mTc), a decay product of molybdenum (99Mo), is employed as radioisotope in nuclear medicine. Several practical devices known as generators are commercially available which enable the user to separate the daughter from the parent radionuclide. The present study is focused on quality control of chromatographic technetium generator. A properly constructed generator should comply with international requirements of radionuclide purity of 90Sr/99Mo ? 6 x 10-8 and 89Sr/99Mo ? 6 x 10-7. For this purpose an analytical method was optimized to quantify radiostrontium (89Sr and 90Sr) in sodium molybdate [Na299 MoO4] solution, a fission product used for 99Mo/99mTc generators. Dowex 1 x 8 and alumina were used in sequence followed by tributyl phosphate extraction for radiostrontium separation. Cerenkov measurement of 89Sr and 90Sr (through its descendent 90Y) was performed using Perkin Elmer Tricarb LSA 3170 with detection efficiency of 42 and 14 %, respectively. Since efficiency of Cherenkov counting is sensitive to presence of color, spectral index of sample was used to correct the counting efficiency. The chemical recovery for strontium was 22 % and for yttrium was 80 % as determined by inductively coupled plasma optical emission spectrometry. Lower limit of detection was found to be 6.3 and 14.4 Bq L-1 for 90Sr and 89Sr, respectively with 60 min counting time. Hence method can be applied successfully to analyze 89,90Sr in fission molybdenum used as radiopharmaceutical with a relative error of <10 %. (author)

  19. Anodic dissolution of UO2 in slightly alkaline sodium perchlorate solutions

    International Nuclear Information System (INIS)

    The anodic dissolution of UO2 has been studied in aqueous sodium perchlorate solutions at pH ? 9.5. Under potentiostatic conditions two distinct regions of oxidation/dissolution behaviour were observed. In the potential (E) range 0.100 V A, QC respectively) obtained by integration of the anodic current-time plots (QA) and cathodic potential scans to reduce accumulated oxidized surface films (QC), it was shown that > ? 90% of the anodic oxidation current went to produce these films. For E > ? 0.350 V, steady-state currents were obtained and measurements of QA and QC showed the majority of the current went to produce soluble species. The film blocking anodic dissolution appeared to be either UO2.27 or, more probably, UO3.2H2O located primarily at grain boundaries. It is proposed that, at the higher potentials, rapid oxidation and dissolution followed by the hydrolysis of dissolved uranyl species leads to the development of acidic conditions in the grain boundaries. At these lower pH values the UO3.2H2O is soluble and therefore does not accumulate. Alternatively, if this oxide has been formed by prior oxidation at a lower potential, the formation of protons on oxidizing at E > ? 0.350V causes its redissolution, allowing the current to rise to a steady-state value. On the basis of Tafel slopes, an attempt was made to demonstrate that the observed behaviour was consistent with dissolution under acidic conditions. This analysis was only partially successful. (author) 34 refs. 11 figs

  20. The (13)C bicarbonate method

    DEFF Research Database (Denmark)

    Junghans, Peter; Larsson, Caroline; Jensen, Rasmus Bovbjerg; Tauson, Anne-Helene

    2015-01-01

    We reconsider the principle of the (13)C bicarbonate (NaH(13)CO3) method ((13)C-BM) for the determination of the CO2 production to obtain an estimate of energy expenditure (EE). Its mathematical concept based on a three-compartmental model is related to the [(15)N]glycine end product method. The CO......2 production calculated by the (13)C-BM, RaCO2((13)C) is compared to the result from the indirect calorimetry, RCO2(IC). In an interspecies comparison (dog, goat, horse, cattle, children, adult human; body mass ranging from 15 to 350?kg, resting and fasting conditions) we found an excellent...... correlation between the results of (13)C-BM and IC with RCO2(IC)?=?0.703?×?RaCO2((13)C), (R(2)?=?0.99). The slope of this correlation corresponds to the fractional (13)C recovery (RF((13)C)) of (13)C in breath CO2 after administration of NaH(13)CO3. Significant increase in RF((13)C) was found in physically...

  1. Antimicrobial activity of complete denture cleanser solutions based on sodium hypochlorite and Ricinus communis – a randomized clinical study

    Science.gov (United States)

    SALLES, Marcela Moreira; BADARÓ, Maurício Malheiros; de ARRUDA, Carolina Noronha Ferraz; LEITE, Vanessa Maria Fagundes; da SILVA, Cláudia Helena Lovato; WATANABE, Evandro; OLIVEIRA, Viviane de Cássia; PARANHOS, Helena de Freitas Oliveira

    2015-01-01

    ABSTRACT To preserve oral health and to maintain the prosthetic devices, it is important not only to improve the properties of commonly known hygiene products, but also to investigate new materials with antimicrobial action. Objectives This study evaluated the antimicrobial activity of sodium hypochlorite (0.25% and 0.50%) and 10% Ricinus communis’ solutions against specific microorganisms. Material and Methods Sixty four maxillary complete denture wearers were instructed to brush their dentures three times a day and to soak them (20 min/day) in the solutions: SH1: 0.25% sodium hypochlorite; SH2: 0.5% sodium hypochlorite; RC: 10% R. communis oil; and C: 0.85% saline (control). The solutions were used for 7 days in a randomized sequence. Following each period of use, there was a 1-week washout period. Antimicrobial activity was determined by Colony Forming Units (CFU) counts of Streptococcus mutans, Candida spp., and gram-negative microorganisms. For collecting biofilm, the internal surface of maxillary dentures was brushed with saline solution, and biofilm suspension obtained. After dilutions (100 - 10-3), aliquots were seeded in Mitis salivarius, CHROMagar Candida®, and MacConkey agar for detecting S. mutans, Candida spp., or gram-negative microorganisms, respectively. After incubation, colonies were counted, and CFU/mL values were calculated. Then, transformation - log10 (CFU+1) - data were analyzed using the Friedman test (?=0.05). Results showed significant differences between the solutions (p<0.001). Results All three solutions showed antimicrobial activity against S. mutans. Against Candida spp., RC and SH1 solutions showed similar effect while SH2 showed superior activity. SH1 and SH2 solutions showed antimicrobial action against gram-negative microorganisms. The Candida species most frequently isolated was C. albicans, followed by C. tropicalis and C. glabrata. Conclusions The 0.5% sodium hypochlorite solution was the most effective and might be used to control denture biofilm. C. albicans was the most frequently isolated Candida sp. PMID:26814466

  2. Synthesis, Optical and Thermal studies on novel nonlinear optical L–Histidine Sodium Thiosulphate crystal by solution growth technique

    OpenAIRE

    M. Radha Ramanan; Radhakrishnan, R.; Krishnan, S.; V. Chithambaram

    2013-01-01

    A semi organic non-linear optical single crystal of L–Histidine Sodium Thiosulphate has been grown from aqueous solution by slow evaporation technique. The lattice parameters of the grown crystals were identified using single crystal X-ray analysis. The functional groups present in the crystal were identified using FTIR analysis. Optical absorption studies have confirmed that the grown crystal possesses less absorption in the entire visible region and UV cut-off is...

  3. Corrosion resistance of ?-solid solution and hardening ?'-phase of nickel alloys in sodium sulfate and chloride melts

    International Nuclear Information System (INIS)

    Corrosion testings of model alloys, corresponding by chemical composition to simple and complex-alloyed ?- and ?'-phases of nickel heat-resistant alloys are conducted in sodium sulfate and chloride melts. It is ascertained that heat resistant nickel alloys containing over 50 % of hardening ?'-phase, are subject to disastrous sulfide corrosion (SC). Resistance against SC alloys containing below 50 % of ?'-phase is determined by the resistance of ?-solid solution. 10 refs., 3 figs., 2 tabs

  4. Study of interaction of bismuth, strontium, calcium copper, lead nitrates solutions with sodium oxalate solution with the aim of HTSC synthesis

    International Nuclear Information System (INIS)

    With the aim of developing a new technique for HTSC oxides synthesis on the base of combined sedimentation of hydroxy salts and their heat treatment is studied interaction of bismuth, strontium, calcium, copper and lead nitrates with alkali solution of sodium oxalate. Conditions for total sedimentation of all five metals from the solution are found. The phase composition of interaction products is determined. It is established that they are high-dispersed homogeneous mixture of three phases of variable composition: twin hydroxalate of copper-bismuth, lead hydroxalate and twin oxalate of strontium-calcium. After heat treatment of the phases are obtained the HTSC oxides

  5. Comparison of 2% chlorhexidine and 5.25% sodium hypochlorite irrigating solutions on postoperative pain: A randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Bashetty Kusum

    2010-01-01

    Full Text Available Aim: To compare the levels of postoperative pain after cleaning and shaping of root canals using two different root canal irrigants for debridement. Materials and Methods: Forty patients with irreversible pulpitis, pulp necrosis and non-vital teeth exhibiting acute apical periodontitis requiring root canal treatment were included. At random, canals were cleaned and shaped with the following protocols. 2% chlorhexidine solution in group I and 5.25% sodium hypochlorite solution in group II were used as an irrigants. Access cavities were closed with a sterile cotton pellet and cavit. The patients recorded degree of pain at various time intervals after cleaning and shaping on a visual analogue scale for 1 week. Results: The mean pain score for group I was between 0.65 and 3.35 and for group II was between 0.95 and 4.50. There was significant difference in the pain level between the two groups only at 6 th hour postoperatively (P<0.05 and the pain was more in sodium hypochlorite group. Conclusions: More pain was present in teeth irrigated using 5.25% sodium hypochlorite when compared to that in teeth irrigated using 2% chlorhexidine solution. Significant difference in pain level was present only at 6th hour postoperatively, and at all other periods (24 th hour, 4 th and 7 th days there was no significant difference in pain level between the two groups.

  6. Solution-deposited sodium beta-alumina gate dielectrics for low-voltage and transparent field-effect transistors.

    Science.gov (United States)

    Pal, Bhola N; Dhar, Bal Mukund; See, Kevin C; Katz, Howard E

    2009-11-01

    Sodium beta-alumina (SBA) has high two-dimensional conductivity, owing to mobile sodium ions in lattice planes, between which are insulating AlO(x) layers. SBA can provide high capacitance perpendicular to the planes, while causing negligible leakage current owing to the lack of electron carriers and limited mobility of sodium ions through the aluminium oxide layers. Here, we describe sol-gel-beta-alumina films as transistor gate dielectrics with solution-deposited zinc-oxide-based semiconductors and indium tin oxide (ITO) gate electrodes. The transistors operate in air with a few volts input. The highest electron mobility, 28.0 cm2 V(-1) s(-1), was from zinc tin oxide (ZTO), with an on/off ratio of 2 x 10(4). ZTO over a lower-temperature, amorphous dielectric, had a mobility of 10 cm2 V(-1) s(-1). We also used silicon wafer and flexible polyimide-aluminium foil substrates for solution-processed n-type oxide and organic transistors. Using poly(3,4-ethylenedioxythiophene) poly(styrenesulphonate) conducting polymer electrodes, we prepared an all-solution-processed, low-voltage transparent oxide transistor on an ITO glass substrate. PMID:19838183

  7. Sodium-water steam generator safety problems and their solution in the USSR

    International Nuclear Information System (INIS)

    The main results of malfunction experimental studies connected with sodium-water interaction are presented. Considered are the main principles of calculational methods elaborated in order to analyze accidents in the steam generator and in the sodium circuit of an NPP with a fast reactor. Stated are the USSR modern approach to safety problems of the sodium-water steam generators with one-wall separation of coolants and demands to their emergency protective systems. It is shown that steam generators with sectioned design and appropriate procective system have some advantages; these designs allow one to localize consequences of an accident in a demaged area and to provide (if necessary) running of the steam generator using intact sections regardless of the initial volume of water flow into sodium

  8. A Low-Field NMR Study on the Water Condition of Tripe Swelling in Sodium Carbonate-Solution

    Directory of Open Access Journals (Sweden)

    Ying Han

    2013-06-01

    Full Text Available In this paper, a low-field NMR study was performed to obtain the information on the water condition of tripe swelling in sodium carbonate-solution (Na2CO3-solution. The study researched the water state during different soaking times, concluded that the crispy cooked tripe is closely related with transverse relaxation time (T2 rather than water content. In addition, the water mobility was also found to be affected by soaking time. The study demonstrated that NMR T2 relaxometry was a potential tool to explore the water state, mobility and the way the different water components shift.

  9. Pancreatic bicarbonate secretion involves two proton pumps

    DEFF Research Database (Denmark)

    Novak, Ivana; Wang, Jing; Henriksen, Katrine L.; Haanes, Kristian A; Krabbe, Simon; Nitschke, Roland; Hede, Susanne E

    2011-01-01

    Pancreas secretes fluid rich in digestive enzymes and bicarbonate. The alkaline secretion is important in buffering of acid chyme entering duodenum and for activation of enzymes. This secretion is formed in pancreatic ducts, and studies to date show that plasma membranes of duct epithelium express H(+)/HCO(3)(-) transporters, which depend on gradients created by the Na(+)/K(+)-ATPase. However, the model cannot fully account for high-bicarbonate concentrations, and other active transporters, i.e....

  10. Bicarbonate utilization by leaf protoplasts from Potamogeton

    International Nuclear Information System (INIS)

    Leaves from the submerged angiosperm P. lucens are able to assimilate bicarbonate. These leaves behave polarly: during bicarbonate utilization protons (H+) are excreted by the cells of the lower epidermis, while hydroxyl (OH-) ions are excreted by the upper epidermal cells. It has been proposed that acidification of the apoplast is a prerequisite for bicarbonate utilization. To test this hypothesis 14C fixation by protoplasts was determined at different pH values. Also experiments, using the isotopic disequilibrium technique were performed. They showed that at pH values > 8, bicarbonate is a major carbon source for photosynthesis in protoplasts, despite the absence of cell walls and polarity. At pH values around 6, the rate of 14C-fixation in protoplasts equals that of intact leaves. At pH values > 8, however, intact leaves show a higher rate. From this, and other experiments, the authors conclude that at least 2 processes contribute to bicarbonate utilization in P. lucens leaves: active transport (H+-HCO3- symport?) and acidification of the apoplast resulting in the conversion of bicarbonate into CO2. Polarity may increase the efficiency of both

  11. Water-compatible surface imprinting of 'Saccharin sodium' on silica surface for selective recognition and detection in aqueous solution.

    Science.gov (United States)

    Zhao, Song; Yang, Xin; Zhao, Haitian; Dong, Aijun; Wang, Jing; Zhang, Min; Huang, Weiwei

    2015-11-01

    In this work, a saccharin sodium imprinted nanoparticles composite material has been successfully synthesized in aqueous solution. This molecular imprinted material has promising practical utility in the detection of saccharin sodium. First, we synthesized SiO2 nanoparticles, followed by the modification of functional amino group. Then we used functionalized SiO2@NH2 as the cores, saccharin sodium as the template, acrylic acid (AA) as the functional monomer and ammonium persulphate (APS) as the initiator. Molecularly imprinted nanoparticles (MIPs) were synthesized by surface-imprinted polymerization under airtight tubes at 60°C for 12h. MIPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA). The binding experiments were shown to have relatively high adsorption capacity (8.965mgg(-1)) and selective recognition ability over structurally related compounds. Therefore, MIPs provide a sensitive and selective approach and offer the potential to become a new key for the detection of saccharin sodium. PMID:26452882

  12. Inhibition of cobalt active dissolution by benzotriazole in slightly alkaline bicarbonate aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Gallant, Danick [Departement de Chimie, Universite Laval, Quebec (Canada); Departement de Biologie, Chimie et Geographie, Universite du Quebec a Rimouski, 300, Allee des Ursulines, Rimouski, Quebec (Canada); E-mail: danick.gallant.1@ulaval.ca; Pezolet, Michel [Departement de Chimie, Universite Laval, Quebec (Canada)]. E-mail: michel.pezolet@chm.ulaval.ca; Simard, Stephan [Departement de Chimie, Universite Laval, Quebec (Canada); Departement de Biologie, Chimie et Geographie, Universite du Quebec a Rimouski, 300, Allee des Ursulines, Rimouski, Quebec (Canada); E-mail: stephan_simard@uqar.qc.ca

    2007-04-20

    The efficiency of benzotriazole as inhibiting agent for the corrosion of cobalt was probed at pH ranging from 8.3 to 10.2 in a sodium bicarbonate solution, chosen to simulate mild natural environments. From electrochemical, Raman spectroscopy, atomic force microscopy and ellipsometry experiments, we have demonstrated that benzotriazole markedly affects the electrodissolution reactions, which become modeled by the formation of a [Co(II)(BTA){sub 2}.H{sub 2}O] {sub n} film according to two different mechanisms. Surface-enhanced Raman spectroscopy has shown that the polarization of a cobalt electrode at cathodic potentials with respect to its potential of zero charge allows a mechanism of specific adsorption of the neutral form of benzotriazole to take place through a suspected metal-to-molecule electron transfer and which follows Frumkin's adsorption isotherms. At the onset of the anodic dissolution, some experimental evidence suggests that these adsorbed neutral benzotriazole molecules deprotonate to yield a very thin [Co(II)(BTA){sub 2}.H{sub 2}O] {sub n} polymer-like and water-insoluble protective film, responsible for the inhibition of active dissolution processes occurring at slightly more anodic potentials. In the anodic dissolution region, deprotonated benzotriazole species present in the bulk solution favors the formation of a multilayered [Co(II)(BTA){sub 2}.H{sub 2}O] {sub n} film, which also contributes to the inhibition of any further cobalt dissolution usually observed at higher electrode potentials.

  13. The chemical interactions of sodium with urania, plutonia and their solid solutions

    International Nuclear Information System (INIS)

    The chemical interactions between sodium and dense sintered spheres of urania, urania-plutonia and urania-plutonia doped with various cations which simulate the presence of fission products have been studied at 1050 and 16000C. The formation of the compounds Na3Usub(1-x)Pusub(x)O4 and Na3Usub(1-x-y)Pusub(x)Fpsub(y)O4 (where Fp represents the added cations) in the reaction of sodium with the oxides results in the sintering together of the spheres; this effect was less pronounced after prolonged heating at 16000C. Because there was essentially no reaction between the spheres of urania and sodium, the sticking together did not occur. For all the oxides, pronounced grain growth was observed during reaction with sodium at 16000C. The thermodynamic oxygen potentials for the phase fields containing liquid sodium, the oxide and the compound Na3XO4 where X is U, Pu or Usub(1-x)Pusub(x), have been determined in the temperature range 825-1000 K using an EMF cell technique with a thoria-yttria electrolyte. The values for the oxygen potentials were found to be similar for all the systems examined. (author)

  14. Sonophotocatalytic Reaction of Sodium Chloride Solution: Comparison of Reaction Products from Sodium Chloride Solution with Those from Pure Water and Influence of Insoluble Photocatalyst on Sonochemical Reaction

    Science.gov (United States)

    Harada, Hisashi

    2000-05-01

    A sonophotocatalytic reaction of NaCl solution was performed. Hydrogen and oxygen were obtained continuously. A sonophotocatalytic reaction is a photocatalytic reaction with ultrasonic irradiation or the simultaneous irradiation of light and ultrasound with a photocatalyst. The higher the concentration of NaCl in a solution, the lower the amount of products obtained. However, there was negligible influence on the products at lower concentrations. Therefore, it was concluded that the impurities such as chloride ions, from the photocatalyst had negligible effect on the sonophotocatalysis of water. It was also demonstrated that a suitable photocatalyst particle size must be selected for the sonophotocatalytic reaction to proceed. The possibility of decomposition of seawater to H2 and O2 was also examined.

  15. Rheological properties of pullulan-sodium alginate based solutions during film formation.

    Science.gov (United States)

    Xiao, Qian; Tong, Qunyi; Zhou, Yujia; Deng, Fangming

    2015-10-01

    During film formation, the rheological properties of pullulan, sodium alginate, and blends, dried at 50°C were studied using an oscillatory rheometer. According to the drying curves, the drying process of pullulan, alginate, and blend films was divided into three stages. At the first drying stage, four samples exhibited typical liquid-like viscoelastic behavior. As the drying proceeded (polysaccharide concentration up to 75%), pure pullulan chains formed an entangled network, whereas coupling of alginate molecules gave a weak gel. At this drying stage, complex viscosity data for 75% alginate and blends were fitted with the power law equation. The effects of drying on the mechanical properties of pullulan-sodium alginate based samples were analyzed using the generalized Maxwell model, and their relaxation spectra were determined. The rheological properties during drying obtained from this study is essential for understanding film-forming mechanism and predicting the properties of pullulan-sodium alginate based edible films. PMID:26076600

  16. Effect of fluoride sodium mouthwash solutions on cpTI: evaluation of physicochemical properties

    Scientific Electronic Library Online (English)

    Marcelo Bighetti, Toniollo; Rodrigo, Galo; Ana Paula, Macedo; Renata Cristina Silveira, Rodrigues; Ricardo Faria, Ribeiro; Maria da Gloria Chiarello de, Mattos.

    2012-10-01

    Full Text Available Os efeitos do fluoreto, o qual está presente em diferentes produtos de higiene oral, necessita de maiores investigações, pois pouco se sabe sobre seus efeitos na superfície do titânio, o qual possui amplo uso na implantodontia. Este estudo objetivou avaliar a superfície do titânio comercialmente pur [...] o (cpTi) após exposição a diferentes concentrações de fluoreto de sódio (NaF). A hipótese testada neste estudo foi que diferentes concentrações de NaF aplicadas em diferentes intervalos de tempo seriam capazes de afetar diferentemente a superfície do titânio. Os tratamentos realizados foram: GA (controle): imersão em água destilada; GB: imersão diária por 3 min em NaF a 0,05%; GC: imersão diária por 3 min em NaF a 0,2%; GD: imersão quinzenal por 3 min em NaF a 0,05%; e GE: imersão quinzenal por 3 min em NaF a 0,2%. O tempo do experimento foi de 60 dias. A análise da rugosidade foi efetuada inicialmente e a cada 15 dias. Após 60 dias foi realizada análise de corrosão e polarização anódica. As amostras foram analisadas em MEV. Os dados de rugosidade foram analisados por ANOVA e não houve diferença estatisticamente significante entre grupos e entre tempos. Os dados de corrosão (i corr) foram analisados pelo teste de Mann-Whitney e foram encontradas diferenças significantes entre GA e GC, GC e GB, GC e GD, GC e GE. A MEV evidenciou que a superfície do titânio exposto ao NaF apresentou corrosão variando de acordo com a concentração. Com base nos dados encontrados conclui-se que o uso de solução NaF a 0,05% em cpTi é seguro, enquanto a solução NaF 0,2% para uso diário deve ser cuidadosamente avaliada. Abstract in english The effects of fluoride, which is present in different oral hygiene products, deserve more investigation because little is known about their impact on the surface of titanium, which is largely used in Implantology. This study evaluated the surface of commercially pure titanium (cpTi) after exposure [...] to different concentrations of sodium fluoride (NaF). The hypothesis tested in this study was that different concentrations of NaF applied at different time intervals can affect the titanium surface in different ways. The treatments resulted in the following groups: GA (control): immersion in distilled water; GB: immersion in 0.05% NaF for 3 min daily; GC: immersion in 0.2% NaF for 3 min daily; GD: immersion in 0.05% NaF for 3 min every 2 weeks; and GE: immersion in 0.2% NaF for 3 min every 2 weeks. The experiment lasted 60 days. Roughness was measured initially and every 15 days subsequently up to 60 days. After 60 days, corrosion analysis and anodic polarization were done. The samples were examined by scanning electron microscopy (SEM). The roughness data were analyzed by ANOVA and there was no significant difference among groups and among time intervals. The corrosion data (i corr) were analyzed by the Mann-Whitney test, and significant differences were found between GA and GC, GB and GC, GC and GD, GC and GE. SEM micrographs showed that the titanium surface exposed to NaF presented corrosion that varied with the different concentrations. This study suggests that the use of 0.05% NaF solution on cpTi is safe, whereas the 0.2% NaF solution should be carefully evaluated with regard to its daily use.

  17. Effect of lithium on the properties of a liquid crystal formed by sodium dodecylsulphate and decanol in aqueous solution

    Science.gov (United States)

    Bahamonde-Padilla, V. E.; Espinoza, Javier; Weiss-López, B. E.; Cascales, J. J. López; Montecinos, R.; Araya-Maturana, R.

    2013-07-01

    Understanding the molecular interactions that rule the physicochemical properties of molecular assemblies is of particular interest when trying to explain the behavior of much more complicated systems, such as the cell membranes. This work was devoted to study a discotic nematic lyotropic liquid crystal, formed by sodium dodecylsulphate (3% SDS-d25) and decanol (20% DeOH-?-d2), dissolved in aqueous solutions (0.1% D2O) of Na2SO4 or Li2SO4. The average size of the aggregates was estimated using fluorescence quenching experiments, and their dynamics were studied by measuring the 2H-NMR quadrupole splitting (??Q) and the longitudinal relaxation times (T1) of the deuterated species. To provide an atomic insight into these assemblies, molecular dynamics simulations of the systems were carried out with atomic detail. As a previous step in this study, a reparameterization of the standard GROMOS 87 force field was required to perform the equilibrated simulations and to prevent instabilities emerging during the simulations. Finally, an excellent agreement between simulation and experimental data was obtained. In addition, variations in the long range electrostatic interactions at the aggregate/solution interface, the orientation and the reorientational relaxation time of the water dipole, the translational diffusion coefficient of sodium ions, and the amphiphile-counterion coordination associated with the presence of Li+ in the solution were other key aspects investigated to explain the variation in the quadrupole splittings (??Q) in the presence of lithium in solution.

  18. Lactated Ringer's solution or 0.9% sodium chloride as fluid therapy in pigeons (Columba livia submitted to humerus osteosynthesis

    Directory of Open Access Journals (Sweden)

    Adriano B. Carregaro

    2015-01-01

    Full Text Available The study aimed to compare the effects of intraosseous infusion of lactated Ringer's and 0.9% sodium chloride solutions on the electrolytes and acid-base balance in pigeons submitted to humerus osteosynthesis. Eighteen pigeons were undergoing to isoflurane anesthesia by an avalvular circuit system. They were randomly assigned into two groups (n=9 receiving lactated Ringer's solution (LR or 0.9% sodium chloride (SC, in a continuous infusion rate of 20mL/kg/h, by using an intraosseous catheter into the tibiotarsus during 60-minute anesthetic procedure. Heart rate (HR, and respiratory rate (RR were measured every 10 min. Venous blood samples were collected at 0, 30 and 60 minutes to analyze blood pH, PvCO2, HCO3 -, Na+ and K+. Blood gases and electrolytes showed respiratory acidosis in both groups during induction, under physical restraint. This acidosis was evidenced by a decrease of pH since 0 min, associated with a compensatory response, observed by increasing of HCO3 - concentration, at 30 and 60 min. It was not observed any changes on Na+ and K+ serum concentrations. According to the results, there is no reason for choosing one of the two solutions, and it could be concluded that both fluid therapy solutions do not promote any impact on acid-base balance and electrolyte concentrations in pigeons submitted to humerus osteosynthesis.

  19. Stress corrosion cracking of 13% Cr martensitic steels in sodium chloride solutions in the presence of thiosulphate

    International Nuclear Information System (INIS)

    The stress corrosion cracking (SCC) susceptibility of 13% Cr martensitic (UNS S42000) and supermartensitic (UNS S41125) steels in sodium chloride solutions in the presence of thiosulphate was evaluated by slow strain rate tests (SSRT). The tests were performed in 5% sodium chloride solutions buffered at pH 2.7, 3.5, 4.5 and 6.0 in the absence and presence of thiosulphate in a concentration range between 10-6 and 10-3 M, at 25 ± 0.1 C. The electrochemical behaviour of the two steels in the different solutions was determined by recording the anodic and cathodic polarisation curves. 13% Cr martensitic steel showed SCC in 5% sodium chloride solutions with pH ? 4.5 in the presence of 3 x 10-6 thiosulphate. Decreasing the chloride ion concentration from 50 to 10 g/l, the critical concentration of thiosulphate to provoke SCC susceptibility increased from 3 x 10-6 to 1 x 10-5 M. The resistance to SCC of the supermartensitic steel was higher than that of the martensitic steel. The critical concentration of thiosulphate to induce SCC on the supermartensitic steel were 1 x 10-5 M at pH 2.7 and 1 x 10-4 M at pH 3.5. At pH ? 4.5 the supermartensitic steel did not crack. The anodic and cathodic polarisation curves evidenced the influence of the thiosulphate on the corrosion and the activation effect on the steels. The SCC of the two steels was attributed to hydrogen embrittlement produced by sulphur and hydrogen sulphide formed by dismutation and reduction of thiosulphate. (orig.)

  20. Model investigations for trace analysis of iodine, uranium, and technetium in saturated sodium chloride leaching solutions of stored radioactive waste

    International Nuclear Information System (INIS)

    This paper describes the development of a time and cost saving chromatographic technique, which allows the matrix to be separated and the most important species to be analyzed in a leaching solution of vitrified radioactive waste. Uranium, iodine, and technetium were chosen for the model technique to be elaborated. In a first step, iodide and pertechnetate were separated from the matrix by the strongly basic AG 1X 8 anion exchange resin and then separated from each other by selective elution. The uranyl ions eluted with the sodium chloride matrix were separated from the excess of sodium chloride in a second step, again by adsorption to the strongly basic resin. The ion-selective electrode was found to be a suitable tool for iodide analysis. Pertechnetate was analysed by means of liquid scintillation. Uranium was determined by ICP-AES. (orig./RB)

  1. A Small-Angle Neutron Scattering Study on Micelle Structural Transition at Low concentration of Sodium Dodecyl Sulfate Micellar Solution

    International Nuclear Information System (INIS)

    The micelle structural transition of 0.02 M sodium dodecyl sulfate (SDS) micellar solution in addition of sodium chloride (NaCI) salt has been investigated using a Small-Angle Neutron Scattering (SANS) technique. The micelle progressively changed not just the shape but also the size by addition of salt from 0.02 M to 0.40 M. A nearly spherical micelle transforms into an ellipsoidal micelle as the major axis of micelle increases from 19.0 Angstrom to 27.3 Angstrom with a fixed minor axis of 16.7 Angstrom. The present of salt noticeable reduces the repulsion force between the charge head groups of SDS molecule that decreases the critical micelle concentration (CMC). Furthermore, it leads to decrease the free energy on micellization in which the molecules of SDS easily assembled to form a large size micelle. (author)

  2. Behaviour of 29Si NMR and infrared spectra of aqueous sodium and potassium silica solutions as a function of (SiO2/M2+O) ratio

    International Nuclear Information System (INIS)

    Sodium and potassium solutions of silica with silica concentration of 1,4 mo/kg and Rms = SiO2/M+2O ratios of 4.56 to 1.6 were obtained by depolymerization of amorphous silica gel in sodium and potassium hydroxide. Solutions have been characterized by 29Si NMR and infrared spectroscopy. The results indicated that Na+ and K+ exhibit the same behaviour during the depolymerization of silica. (authors). 11 refs., 4 figs., 2 tabs

  3. The Corrosion Behavior of Nickel and Inconel 600 in Sodium Hydroxide and Hydrochloric Acid Solution at 280 .deg. C

    International Nuclear Information System (INIS)

    The corrosion behavior of nickel and Inconel 600 has been investigated by the weight change measurement method at pH ranges 3?13 of the solution. The specimens were exposed to aqueous solutions in a static autoclave at 280 .deg. C for 210 hours. The pH of the solutions was adjusted by hydrochloric acid and sodium hydroxide and the dissolved oxygen concentration was fixed as 10 ppb by using pure nitrogen gas. Weight loss of Inconel 600 was much less than that of nickel over the tested pH ranges. At pH 9.5, nickel and Inconel 600 showed the minimum weight loss phenomenon and the values of weight loss were 1.5mg/dm2 and 0.9mg/dm2, respectively. Microscopic examination showed that nickel surface was attacked uniformly, whereas Inconel 600 surface was not greatly

  4. Cellular Cycling, Carbon Utilization, and Photosynthetic Oxygen Production during Bicarbonate-Induced Triacylglycerol Accumulation in a Scenedesmus sp.

    Directory of Open Access Journals (Sweden)

    Robert D. Gardner

    2013-11-01

    Full Text Available Microalgae are capable of synthesizing high levels of triacylglycerol (TAG which can be used as precursor compounds for fuels and specialty chemicals. Algal TAG accumulation typically occurs when cellular cycling is delayed or arrested due to nutrient limitation, an environmental challenge (e.g., pH, light, temperature stress, or by chemical addition. This work is a continuation of previous studies detailing sodium bicarbonate-induced TAG accumulation in the alkaline chlorophyte Scenedesmus sp. WC-1. It was found that upon sodium bicarbonate amendment, bicarbonate is the ion responsible for TAG accumulation; a culture amendment of approximately 15 mM bicarbonate was sufficient to arrest the cellular cycle and switch the algal metabolism from high growth to a TAG accumulating state. However, the cultures were limited in dissolved inorganic carbon one day after the amendment, suggesting additional carbon supplementation was necessary. Therefore, additional abiotic and biotic experimentation was performed to evaluate in- and out-gassing of CO2. Cultures to which 40–50 mM of sodium bicarbonate were added consumed DIC faster than CO2 could ingas during the light hours and total photosynthetic oxygen production was elevated as compared to cultures that did not receive supplemental inorganic carbon.

  5. Bicarbonate-Regulated Soluble Adenylyl Cyclase

    Directory of Open Access Journals (Sweden)

    Wuttke MS

    2001-07-01

    Full Text Available Soluble adenylyl cyclase (sAC represents a novel form of mammalian adenylyl cyclase structurally, molecularly, and biochemically distinct from the G protein-regulated, transmembrane adenylyl cyclases (tmACs. sAC possesses no transmembrane domains and is insensitive to classic modulators of tmACs, such as heterotrimeric G proteins and P site ligands. Thus, sAC defines an independently regulated cAMP signaling system within mammalian cells. sAC is directly stimulated by bicarbonate ion both in vivo in heterologously expressing cells and in vitro using purified protein. sAC appears to be the predominant form of adenylyl cyclase (AC in mammalian sperm, and its direct activation by bicarbonate provides a mechanism for generating the cAMP required to complete the bicarbonate-induced processes necessary for fertilization, including hyperactivated motility, capacitation, and the acrosome reaction. Immunolocalization studies reveal sAC is also abundantly expressed in other tissues which respond to bicarbonate or carbon dioxide levels suggesting it may function as a general bicarbonate/CO(2 sensor throughout the body.

  6. Solubility of unirradiated UO2 fuel in aqueous solutions. Comparison between experimental and calculated (EQ3/6) data

    International Nuclear Information System (INIS)

    The solubility behaviour of unirradiated UO2 pellets was studied under oxic (air-saturated) and anoxic (N2) conditions in deionized water, in sodium bicarbonate solutions with varying bicarbonate content (60 - 600 ppm), in Allard groundwater simulating granitic fresh groundwater conditions, and in bentonite water simulating the effects of bentonite on granitic fresh groundwater (25 deg C). The release of uranium was measured during static batch dissolution experiments of long duration (2-6 years). A comparison was made with the theoretical solubility data calculated with the geochemical code EQ3/6 in order to evaluate solubility (steady state) limiting factors. (orig.) (26 refs., 32 figs., 13 tabs.)

  7. Effectiveness of sodium benzoate as a freshwater low toxicity antifoulant when dispersed in solution and entrapped in silicone coatings.

    Science.gov (United States)

    Haque, Haroon; Cutright, Teresa J; Newby, Bi-Min Zhang

    2005-01-01

    The traditional solution for preventing organisms from attaching to submerged surfaces is to apply antifouling coatings or biocides. Based on the varied defence mechanisms exhibited by biofilms, the antifoulant needs to prevent bacterial attachment during the early stages of biofilm formation. The potential of benzoic acid and sodium benzoate (NaB) as antifoulants for deterring freshwater bacterial attachment was evaluated with the antifoulants dispersed in solution or entrapped in silicone coatings. Effectiveness was based on the decrease in microbial attachment, limited toxicity, and minimum alteration of the properties of the coatings. The optimal NaB concentration when dispersed in solution, 700 mg l-1, resulted in a biofilm surface coverage of only 3.34% after four weeks. The model silicone, Sylgard 184, demonstrated a better overall performance than the commercial coating, RTV11. Sylgard 184 containing sodium benzoate had 41-52% less biofilm in comparison to the control Sylgard 184, whereas both the control and NaB-entrapped RTV11 coatings had significant biofilm coverage. PMID:16109600

  8. Reappraisal of bicarbonate secretion by the human oesophagus

    DEFF Research Database (Denmark)

    Mertz-Nielsen, A; Hillingsø, Jens; Bukhave, K; Rask-Madsen, J

    1997-01-01

    BACKGROUND AND AIMS: Administration of omeprazole to healthy volunteers was recently reported to increase proximal duodenal mucosal bicarbonate secretion. As human oesophagus also secretes bicarbonate, the hypothesis was tested that omeprazole may stimulate oesophageal bicarbonate secretion and...... measured. RESULTS: The median rates (95% confidence intervals) of intrinsic oesophageal bicarbonate secretion, corrected for contaminating salivary and gastric bicarbonate, were 89 (33-150) and 121 (63-203) mumol/h/10 cm (p > 0.5) in omeprazole and ranitidine treated subjects respectively. Salivary and...... gastric bicarbonate contaminating the oesophagus accounted for 14% and 3%, respectively, of total oesophageal bicarbonate output. CONCLUSIONS: Bicarbonate secretory capacity of the human oesophagus is less than previously assumed, and the clinical relevance of intrinsic oesophageal bicarbonate for mucosal...

  9. Shock Hugoniot and equations of states of water, castor oil, and aqueous solutions of sodium chloride, sucrose and gelatin

    Science.gov (United States)

    Gojani, A. B.; Ohtani, K.; Takayama, K.; Hosseini, S. H. R.

    2016-01-01

    This paper reports a result of experiments for the determination of reliable shock Hugoniot curves of liquids, in particular, at relatively low pressure region, which are needed to perform precise numerical simulations of shock wave/tissue interaction prior to the development of shock wave related therapeutic devices. Underwater shock waves were generated by explosions of laser ignited 10 mg silver azide pellets, which were temporally and spatially well controlled. Measuring temporal variation of shock velocities and over-pressures in caster oil, aqueous solutions of sodium chloride, sucrose and gelatin with various concentrations, we succeeded to determine shock Hugoniot curves of these liquids and hence parameters describing Tait type equations of state.

  10. The effect of sodium hypochlorite solutions on in vitro seedling growth and shoot regeneration of flax (Linum usitatissimum)

    Science.gov (United States)

    Yildiz, Mustafa; Er, Celâl

    2002-04-01

    The aim of this study was to determine the effect of concentration (40, 60, and 80%) and temperature (0, 10, 20, and 30°C) of sodium hypochlorite (NaOCl) solutions on seed germination, in vitro viability and growth of flax seedlings and regeneration capacity of hypocotyl explants. Results showed that seed germination, seedling growth and shoot regeneration were negatively affected by increasing concentration and temperature of disinfectant. The best results in seedling growth and shoot regeneration were obtained when 40% disinfectant concentration at 10°C was used.

  11. Pancreatic bicarbonate secretion involves two proton pumps

    DEFF Research Database (Denmark)

    Novak, Ivana; Wang, Jing; Henriksen, Katrine L.; Haanes, Kristian A; Krabbe, Simon; Nitschke, Roland; Hede, Susanne E

    2011-01-01

    Pancreas secretes fluid rich in digestive enzymes and bicarbonate. The alkaline secretion is important in buffering of acid chyme entering duodenum and for activation of enzymes. This secretion is formed in pancreatic ducts, and studies to date show that plasma membranes of duct epithelium express...... H(+)/HCO(3)(-) transporters, which depend on gradients created by the Na(+)/K(+)-ATPase. However, the model cannot fully account for high-bicarbonate concentrations, and other active transporters, i.e. pumps, have not been explored. Here we show that pancreatic ducts express functional gastric and...... localized to the plasma membranes of pancreatic ducts. Quantitative analysis of H(+)/HCO(3)(-) and fluid transport shows that the H(+)-K(+) pumps can contribute to pancreatic secretion in several species. Our results call for revision of the bicarbonate transport physiology in pancreas, and most likely...

  12. Use of sodium hetastarch (Hespan) solution for reduction of postoperative adhesion formation in rabbits.

    Science.gov (United States)

    Gist, R S; Lu, P Y; Raj, H G; Campbell, C; Elkins, T E

    1996-01-01

    A study was conducted to determine the effect of sodium hydroxy ethyl starch (Hespan) on primary adhesion formation in a rabbit model. Hespan is a readily available volume expander. This was a randomized, double-blinded animal model in which New Zealand white rabbits were subjected to midline celiotomy. Adhesions were created by abrasion in both uterine horns, adjacent bowel, and peritoneum. Necropsies were performed at the 2-week interval and adhesions were graded. Significant decreases in type II and type III adhesions (p = .032 and p = .020, respectively) were demonstrated in Hespan-treated animals. Sodium hetastarch appears to decrease significant adhesion formation in treated animals and may have a role as an adjunct for postsurgical prevention. PMID:8951660

  13. Electrochemical evaluation of sodium metabisulfite as environmentally friendly inhibitor for corrosion of aluminum alloy 6061 in a chloride solution

    International Nuclear Information System (INIS)

    Highlights: • Sodium metabisulfite acts as cathodic-type inhibitor. • The polarization resistance increases with the inhibitor concentration. • The pit nucleation rate decreases with increasing inhibitor concentration. • The current rise linked to pit propagation drops as inhibitor content increases. • The reactions involved in the inhibition actions are pointed out. - Abstract: Inhibition properties of sodium metabisulfite (Na2S2O5) on pitting corrosion of 6061 aluminum alloy, in 5 × 10?2 M NaCl solution of pH near 7.2 at 298 K, are characterized using open circuit potential, polarization resistance, cyclic and chrono-amperometric polarization measurements. In addition, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray photoelectrons are employed. Sodium metabisulfite, which is well compatible with environmental requirements, seems to act as a cathodic-type corrosion inhibitor. The passivation range and the polarization resistance increase with Na2S2O5 concentration. The inhibition effects are also reflected through the substantial reduction of both the rate of pit nucleation and the current rise characterizing the pit propagation progress. The SEM–EDS and XPS analyses reveal the formation of a passive film, which contains sulfur atoms

  14. Numerical solution of melted sodium around the tubes which involves Uranium by finite volume method

    International Nuclear Information System (INIS)

    Finite Volume Method Used for Navier-Stokes and Energy Equations in Laminar and Incompressible 2D Flow of Melted Sodium with Low Heat Flux Pass Upon Four Tubes which Involve Uranium with Constant Heat Flux. In This Case, Velocity Field, Distribution Pressure and Temperature Field resulted around the Tubes. We Will Calculate with Low Prandtl Number 0.0037, 0.0051 and 0.011 and a Range of Reynolds Number which Is a Laminar Flow.

  15. Caffeine, but not bicarbonate, improves 6 min maximal performance in elite rowers

    DEFF Research Database (Denmark)

    Christensen, Peter Møller; Petersen, Mads H; Friis, Signe N; Bangsbo, Jens

    2014-01-01

    This study examined the ergogenic effects in a 6 min maximal performance test (PT) on 12 elite rowers: 6 open-weight (mean ± SD; 25 ± 1 years, and 92 ± 3 kg) and 6 light-weight (25 ± 3 years, and 73 ± 6 kg), following supplementation with caffeine (CAF), sodium bicarbonate (SB), and the combination...... distance; P < 0.05) than in open-weight rowers (0.3% ± 0.8%; P > 0.05). No difference between interventions was observed for readiness and stomach comfort before PT and perceived exertion during PT. This study demonstrates that caffeine ingestion does improve performance in elite rowing. In contrast sodium...... bicarbonate does not appear to be ergogenic, but it does not abolish the ergogenic effect of caffeine....

  16. Sodium phthalamates as corrosion inhibitors for carbon steel in aqueous hydrochloric acid solution

    International Nuclear Information System (INIS)

    Highlights: ? N-Alkyl-sodium phthalamates as corrosion inhibitors for industry in acidic medium. ? Compounds behaved as mixed type inhibitors and followed Langmuir adsorption isotherm. ? Efficiencies were proportional to aliphatic chain length and inhibitor concentration. ? Iron complexes and chelates with phthalamates contributed to carbon steel protection. - Abstract: Three compounds of N-alkyl-sodium phthalamates were synthesized and tested as corrosion inhibitors for carbon steel in 0.5 M aqueous hydrochloric acid. Tests showed that inhibitor efficiencies were related to aliphatic chain length and dependent on concentration. N-1-n-tetradecyl-sodium phthalamate displayed moderate efficiency against uniform corrosion, 42-86% at 25 deg. C and 25-60% at 40 oC. Tests indicated that compounds behave as mixed type inhibitors where molecular adsorption on steel followed Langmuir isotherm, whereas thermodynamic suggested that a physisorption process occurred. XPS analysis confirmed film formation on surface, where Fe+2 complexes and Fe+2 chelates with phthalamates prevented steel from further corrosion.

  17. Volumetric and isentropic compressibility behaviour of aqueous solutions of (polyvinylpyrrolidone + sodium citrate) at T = (283.15 to 308.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Rahmat [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)]. E-mail: rahsadeghi@yahoo.com; Ziamajidi, Fatemeh [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2007-08-15

    The apparent specific volumes and isentropic compressibilities have been determined for polyvinylpyrrolidone in aqueous solutions of sodium citrate by density and sound velocity measurements at T = (283.15 to 308.15) K at atmospheric pressure. The results show a positive transfer volume of PVP from an aqueous solution to an aqueous sodium citrate solution. For low concentrations of PVP, the apparent specific volumes of PVP in water increased along with an increase in the polymer mass fraction, while in aqueous sodium citrate solutions decreased along with an increase in the polymer mass fraction. For high concentrations of PVP, the apparent specific volumes of PVP in water and in aqueous sodium citrate solutions were independent of the polymer mass fraction. The apparent specific isentropic compressibility of PVP is negative at T = (283.15 and 288.15) K, which imply that the water molecules around the PVP molecules are less compressible than the water molecules in the bulk solutions. The positive values of apparent specific isentropic compressibility at T = (298.15, 303.15, and 308.15) K imply that the water molecules around the PVP molecules are more compressible than the water molecules in the bulk solutions. Finally, it was found that the apparent specific isentropic compressibility of PVP increases as the concentration of sodium citrate increases.

  18. Volumetric and isentropic compressibility behaviour of aqueous solutions of (polyvinylpyrrolidone + sodium citrate) at T = (283.15 to 308.15) K

    International Nuclear Information System (INIS)

    The apparent specific volumes and isentropic compressibilities have been determined for polyvinylpyrrolidone in aqueous solutions of sodium citrate by density and sound velocity measurements at T = (283.15 to 308.15) K at atmospheric pressure. The results show a positive transfer volume of PVP from an aqueous solution to an aqueous sodium citrate solution. For low concentrations of PVP, the apparent specific volumes of PVP in water increased along with an increase in the polymer mass fraction, while in aqueous sodium citrate solutions decreased along with an increase in the polymer mass fraction. For high concentrations of PVP, the apparent specific volumes of PVP in water and in aqueous sodium citrate solutions were independent of the polymer mass fraction. The apparent specific isentropic compressibility of PVP is negative at T = (283.15 and 288.15) K, which imply that the water molecules around the PVP molecules are less compressible than the water molecules in the bulk solutions. The positive values of apparent specific isentropic compressibility at T = (298.15, 303.15, and 308.15) K imply that the water molecules around the PVP molecules are more compressible than the water molecules in the bulk solutions. Finally, it was found that the apparent specific isentropic compressibility of PVP increases as the concentration of sodium citrate increases

  19. Infrared optical constants of crystalline sodium chloride dihydrate: application to study the crystallization of aqueous sodium chloride solution droplets at low temperatures.

    Science.gov (United States)

    Wagner, Robert; Möhler, Ottmar; Schnaiter, Martin

    2012-08-23

    Complex refractive indices of sodium chloride dihydrate, NaCl·2H(2)O, have been retrieved in the 6000-800 cm(-1) wavenumber regime from the infrared extinction spectra of crystallized aqueous NaCl solution droplets. The data set is valid in the temperature range from 235 to 216 K and was inferred from crystallization experiments with airborne particles performed in the large coolable aerosol and cloud chamber AIDA at the Karlsruhe Institute of Technology. The retrieval concept was based on the Kramers-Kronig relationship for a complex function of the optical constants n and k whose imaginary part is proportional to the optical depth of a small particle absorption spectrum in the Rayleigh approximation. The appropriate proportionality factor was inferred from a fitting algorithm applied to the extinction spectra of about 1 ?m sized particles, which, apart from absorption, also featured a pronounced scattering contribution. NaCl·2H(2)O is the thermodynamically stable crystalline solid in the sodium chloride-water system below the peritectic at 273.3 K; above 273.3 K, the anhydrous NaCl is more stable. In contrast to anhydrous NaCl crystals, the dihydrate particles reveal prominent absorption signatures at mid-infrared wavelengths due to the hydration water molecules. Formation of NaCl·2H(2)O was only detected at temperatures clearly below the peritectic and was first evidenced in a crystallization experiment conducted at 235 K. We have employed the retrieved refractive indices of NaCl·2H(2)O to quantify the temperature dependent partitioning between anhydrous and dihydrate NaCl particles upon crystallization of aqueous NaCl solution droplets. It was found that the temperature range from 235 to 216 K represents the transition regime where the composition of the crystallized particle ensemble changes from almost only NaCl to almost only NaCl·2H(2)O particles. Compared to the findings on the NaCl/NaCl·2H(2)O partitioning from a recent study conducted with micron-sized NaCl particles deposited onto a surface, the transition regime from NaCl to NaCl·2H(2)O is shifted by about 13 K to lower temperatures in our study. This is obviously related to the different experimental conditions of the two studies. The partitioning between the two solid phases of NaCl is essential for predicting the deliquescence and ice nucleation behavior of a crystalline aerosol population which is subjected to an increasing relative humidity. PMID:22856335

  20. Electrochemical and spectroscopic studies of uranium(IV), -(V), and -(VI) in carbonate-bicarbonate buffers

    International Nuclear Information System (INIS)

    Recently a need for more detailed knowledge of the chemistry of actinide ions in basic media has arisen in connection with deducing their chemistry in the environment. In this work the results of polarographic, cyclic voltammetric, and spectroscopic studies of U(IV), -(V), and -(VI) in carbonate and bicarbonate media are reported. Polarographic studies were in excellent agreement with those reported previously. Cyclic voltammetric scans confirmed the irreversible reduction to U(V) in both solutions, but disproportionation of the U(V) was observed only in the bicarbonate solutions. The oxidation of U(V) in carbonate was followed spectroscopically for the first time. Reduction in bicarbonate produced U(IV), the spectrum of which is now reported and the oxidation of which was also followed spectroscopically for the first time

  1. Bicarbonate adsorption band of the chromatography for carbon isotope separation using anion exchangers

    International Nuclear Information System (INIS)

    The equilibria of bicarbonate ion between two phases were studied for the carbon isotope separation using anion exchangers. The condition of the formation of a bicarbonate adsorption band was quantitatively discussed. The formation of the adsorption band depends on the difference of S-potential which is the sum of the standard redection chemical potentials and L-potential which is the sum of the reduction chemical potential. The isotopic separation factor observed was about 1.012, independent of the concentrations of acid and alkali in the solutions. The isotopic separation factor was considered to be determined by the reaction of bicarbonate ion on anion exchangers and carbon dioxide dissolved in solutions. The enriched carbon isotope whose isotopic abundance ratio (13C/12C) was 1.258 was obtained with the column packed with anion exchangers. (author)

  2. Phase equilibria diagrams, crystal growth peculiarities and Raman investigations of lead and sodium-bismuth tungstate-molybdate solid solutions

    Science.gov (United States)

    Lebedev, Andrei V.; Avanesov, Samvel A.; Yunalan, Tyliay M.; Klimenko, Valeriy A.; Ignatyev, Boris V.; Isaev, Vladislav A.

    2016-02-01

    In this paper a comprehensive study of lead and sodium-bismuth tungstate-molybdate solid solutions was carried out, including the clarification of their structural peculiarities and phase diagrams of PbMoO4-PbWO4 and NaBi(MoO4)2-NaBi(WO4)2 systems, the study of spontaneous Raman spectra of these compounds, as well as preliminary experiments on single crystals growth of lead tungstate-molybdate. The linewidths, peak and integral intensities of the totally symmetric Raman vibrations of solid solutions were estimated in comparison with known SRS-active crystals. The conditions of the Czochralski growth of optically transparent lead tungstate-molybdate mixed crystals were found and SRS effect was observed in these crystals when pumping by 12 ns 1064 nm laser pulses.

  3. A Fiber-Optic Sensor Using an Aqueous Solution of Sodium Chloride to Measure Temperature and Water Level Simultaneously

    Directory of Open Access Journals (Sweden)

    Wook Jae Yoo

    2014-10-01

    Full Text Available A fiber-optic sensor system using a multiplexed array of sensing probes based on an aqueous solution of sodium chloride (NaCl solution and an optical time-domain reflectometer (OTDR for simultaneous measurement of temperature and water level is proposed. By changing the temperature, the refractive index of the NaCl solution is varied and Fresnel reflection arising at the interface between the distal end of optical fiber and the NaCl solution is then also changed. We measured the modified optical power of the light reflected from the sensing probe using a portable OTDR device and also obtained the relationship between the temperature of water and the optical power. In this study, the water level was simply determined by measuring the signal difference of the optical power due to the temperature difference of individual sensing probes placed inside and outside of the water. In conclusion, we demonstrate that the temperature and water level can be obtained simultaneously by measuring optical powers of light reflected from sensing probes based on the NaCl solution. It is anticipated that the proposed fiber-optic sensor system makes it possible to remotely monitor the real-time change of temperature and water level of the spent fuel pool during a loss of power accident.

  4. A fiber-optic sensor using an aqueous solution of sodium chloride to measure temperature and water level simultaneously.

    Science.gov (United States)

    Yoo, Wook Jae; Sim, Hyeok In; Shin, Sang Hun; Jang, Kyoung Won; Cho, Seunghyun; Moon, Joo Hyun; Lee, Bongsoo

    2014-01-01

    A fiber-optic sensor system using a multiplexed array of sensing probes based on an aqueous solution of sodium chloride (NaCl solution) and an optical time-domain reflectometer (OTDR) for simultaneous measurement of temperature and water level is proposed. By changing the temperature, the refractive index of the NaCl solution is varied and Fresnel reflection arising at the interface between the distal end of optical fiber and the NaCl solution is then also changed. We measured the modified optical power of the light reflected from the sensing probe using a portable OTDR device and also obtained the relationship between the temperature of water and the optical power. In this study, the water level was simply determined by measuring the signal difference of the optical power due to the temperature difference of individual sensing probes placed inside and outside of the water. In conclusion, we demonstrate that the temperature and water level can be obtained simultaneously by measuring optical powers of light reflected from sensing probes based on the NaCl solution. It is anticipated that the proposed fiber-optic sensor system makes it possible to remotely monitor the real-time change of temperature and water level of the spent fuel pool during a loss of power accident. PMID:25310471

  5. Inorganic polymers from laterite using activation with phosphoric acid and alkaline sodium silicate solution: Mechanical and microstructural properties

    Energy Technology Data Exchange (ETDEWEB)

    Lassinantti Gualtieri, Magdalena, E-mail: magdalena.gualtieri@unimore.it [Dipartimento di Ingegneria " Enzo Ferrari" , Università degli studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41125 Modena (Italy); Romagnoli, Marcello [Dipartimento di Ingegneria " Enzo Ferrari" , Università degli studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41125 Modena (Italy); Pollastri, Simone; Gualtieri, Alessandro F. [Dipartimento di Scienze Chimiche e Geologiche, Università degli studi di Modena e Reggio Emilia, Via S. Eufemia 19I, I-41121 Modena (Italy)

    2015-01-15

    Geopolymers from laterite, an iron-rich soil available in developing countries, have great potential as building materials. In this work, laterite from Togo (Africa) was used to prepare geopolymers using both phosphoric acid and alkaline sodium silicate solution. Microstructural properties were investigated by scanning electron microscopy, X-ray powder diffraction and mercury porosimetry, whereas thermal properties were evaluated by thermal analyses. The local environment of iron was studied by X-ray Absorption Spectroscopy (XANES region). The mechanical properties were determined. Modulus of Rupture and Young's modulus fell in the ranges 3.3–4.5 MPa and 12–33 GPa, respectively, rendering the materials good candidates for construction purposes. Heating above 900 °C results in weight-gain, presumably due to iron redox reactions. X-ray Absorption Spectroscopy data evidence changes in the chemical and structural environments of iron following thermal treatment of geopolymers. These changes indicate interaction between the geopolymer structure and iron during heating, possibly leading to redox properties. -- Highlights: •Geopolymerization of laterite is promising for fabrication of building materials. •Both phosphoric acid and alkaline sodium silicate solution can be used for activation. •Thermally activated redox properties of the inorganic polymers were observed.

  6. Inorganic polymers from laterite using activation with phosphoric acid and alkaline sodium silicate solution: Mechanical and microstructural properties

    International Nuclear Information System (INIS)

    Geopolymers from laterite, an iron-rich soil available in developing countries, have great potential as building materials. In this work, laterite from Togo (Africa) was used to prepare geopolymers using both phosphoric acid and alkaline sodium silicate solution. Microstructural properties were investigated by scanning electron microscopy, X-ray powder diffraction and mercury porosimetry, whereas thermal properties were evaluated by thermal analyses. The local environment of iron was studied by X-ray Absorption Spectroscopy (XANES region). The mechanical properties were determined. Modulus of Rupture and Young's modulus fell in the ranges 3.3–4.5 MPa and 12–33 GPa, respectively, rendering the materials good candidates for construction purposes. Heating above 900 °C results in weight-gain, presumably due to iron redox reactions. X-ray Absorption Spectroscopy data evidence changes in the chemical and structural environments of iron following thermal treatment of geopolymers. These changes indicate interaction between the geopolymer structure and iron during heating, possibly leading to redox properties. -- Highlights: •Geopolymerization of laterite is promising for fabrication of building materials. •Both phosphoric acid and alkaline sodium silicate solution can be used for activation. •Thermally activated redox properties of the inorganic polymers were observed

  7. In vitro bioactivity of soda lime borate glasses with substituted SrO in sodium phosphate solution

    Directory of Open Access Journals (Sweden)

    Mohamed A. Marzouk

    2014-09-01

    Full Text Available Borate glasses with the basic composition 0.6B2O3·0.2Na2O·0.2CaO and SrO progressively substituting CaO were prepared and characterized for their bone-bonding ability. The obtained glasses were thermally treated and converted to their glass-ceramic derivatives. In this study, FTIR spectral analyses were done for the prepared glasses and glass-ceramics before and after immersion in a sodium phosphate solution for extended times. The appearance of two IR bands within the spectral range 550–680 cm-1 after immersion confirms the formation of hydroxyapatite. X-ray diffraction studies and scanning electron microscope analysis supported the obtained infrared spectroscopy results. The solubility test (measurements of the weight loss in aqueous sodium phosphate solution was conducted for measuring the dissolution of both glassy and crystalline derivatives to find out the role of SrO. The corrosion behaviour of the glasses and glass-ceramics indicate the increase of weight loss with the increase of SrO content. Different suggested proposals were introduced to explain this abnormal behaviour.

  8. Solution enthalpies of sodium, potassium, rubidium and cesium iodates in water at 298.15 K

    International Nuclear Information System (INIS)

    Solution enthalpies ?Hs of soldium, potassium, rubidium and cesium iodates in water at 298.15 K were measured using precision adiabatic-shell calorimeter. ?Hs value was specified for CsIO3. Solution enthalpies of these salts with infinite dilution of solutions were calculated on the basis of obtained data. They were equal to 20.059±0.030, 27.608±0.047, 35.806±0.041 and 39.709±0.060 kJ/mol respectively

  9. Localized corrosion of alloys C-276 and 625 in aerated sodium chloride solutions at 25 to 200 degrees C

    International Nuclear Information System (INIS)

    Two molybdenum-bearing nickel alloys, Alloy C-276 and Alloy 625, were previously identified for consideration as candidate container materials for the Canadian Nuclear Fuel Waste Management Program. Because of the paucity of data for the localized corrosion behaviour of these passive alloys under conditions that may be experienced in a disposal vault, this project was undertaken to study the crevice and pitting corrosion of Alloys C-276 and 625 in chloride solutions at elevated temperatures. Electrochemical and immersion tests have been conducted in neutral sodium chloride solutions (0.1 wt% to saturated) at 25 to 200 degrees C, in an attempt to identify the conditions under which localized corrosion occurs and to relate the actual corrosion behaviour to that expected on the basis of electrochemical studies. Cyclic polarization studies showed that the passivation breakdown potentials move rapidly to more active values with increasing temperatures. Above 100 degrees C the resistance to localized corrosion is greatly reduced. The results of the immersion tests are presented in the form of T versus (C1-) diagrams. These susceptibility diagrams suggest that there is a limiting crevice-corrosion temperature for each alloy in aerated, neutral sodium chloride solutions. Below this temperature corrosion does not occur, regardless of the chloride concentration. The values of the limiting crevice-corrosion temperatures were in the range 100 to 125 degrees C for Alloy C-276 and 100 to 115 degrees C for Alloy 625. Such values suggest that saturation of the chloride solutions by surface boiling could occur without the initiation of localized corrosion. These electrochemical results indicate that a large safety margin for susceptibility to localized corrosion might be found below 100 degrees C

  10. Measurements of density and of thermal expansion coefficient of sodium tetraborate (borax)-UO2 and of sodium metaborate-UO2 solutions

    International Nuclear Information System (INIS)

    Measurements have been performed of the density and volumetric thermal expansion coefficient of liquid sodium tetraborate (borax) and of sodium metaborate both pure and with two different amounts of UO2 dissolved in each. These data are required for the design of core-catchers based on sodium borates. The measurements have been performed with the buoyancy method in the temperature range from 8500C to 13250C. The data for the pure borax and for the sodium metaborate agree reasonably well with the data from the literature, giving confidence that the measurements are correct and the new data for the salts with UO2 are reliable. (orig.)

  11. The absorption spectra of Pu(VI), -(V) and -(IV) produced electrochemically in carbonate-bicarbonate media

    International Nuclear Information System (INIS)

    Absorption spectra in carbonate and bicarbonate media have been measured for various oxidation states of plutonium. The oxidation state of plutonium was adjusted electrochemically (Pu(VI)-V), Esub(f)=+0.11 V vs. SCE) to avoid contamination by redox reagents. In carbonate medium the spectra of Pu(VI) and Pu(V) showed marked differences from the spectra of the same oxidation state in acidic solutions. In bicarbonate the spectra of Pu(VI) and Pu(IV) also differed from the corresponding spectra in acidic media. Reduction to Pu(III) resulted in a precipitate in both carbonate and bicarbonate media. (author)

  12. Bicarbonate versus acetate hemodialysis in ventilated patients.

    Science.gov (United States)

    van Geelen, J A; Woittiez, A J; Schalekamp, M A

    1987-09-01

    Hemodynamic tolerance to bicarbonate versus acetate hemodialysis was studied in seven ventilated, critically ill patients, suffering from acute renal failure. Both kinds of hemodialysis were carried out with a recirculating dialysate delivery system and a relatively low blood flow (180 ml/min). Each patient underwent two hemodialysis procedures, one with bicarbonate and one with acetate, lasting for four hours. Ultrafiltration rates were kept below 250 ml/h and only biocompatible membranes with a relatively small surface area (Biospal 2400, Hospal, France) were used. Despite the mild hemodialysis conditions, hypotensive episodes with a mean blood pressure below 70 mmHg were observed in 3 out of 7 bicarbonate sessions and 4 out of 7 acetate sessions. Thus, we could not demonstrate a hemodynamic advantage of bicarbonate hemodialysis in this group of ventilated patients. This contrasts with other studies conducted in non-ventilated patients. Prevention of hypoxemia by mechanical ventilation and control of vascular tone by the use of vasoactive drugs may be of more clinical relevance than the kind of hemodialysis procedure that is used. PMID:3117466

  13. Surface composition of layers formed after interaction with solutions and electrode properties of alkali-alumoborosilicate glasses. 2. Sodium-alumoborosilicate glass

    International Nuclear Information System (INIS)

    Concentration profiles of the glass surface layer components and quantitative kinetic characteristics of sodium-alumoborosilicate glass (NaAlB) interaction with HF, HCl and salt solutions are compared to corresponding data for potassium-alumoborosilicate (KAlB) and sodium-alumosilicate (NaAl) glasses. The chemical stability of glasses is reduced in NaAl > NaAlB > KAlB series. Boron oxide, being leached in salt solutions, produces low-soluble compounds in the surface layers. Boron presence in a silicate lattice reduces abruptly its resistance to HF solution and to other ones. 9 refs.; 3 figs.; 4 tabs

  14. Attenuation coefficients of sodium chloride for 662 keV ?-radiation, measured in dilute solutions

    International Nuclear Information System (INIS)

    The technique developed for the direct measurement of linear attenuation and mass attenuation (or absorption) coefficients of dilute solutions of salts has been applied to the attenuation of 662 keV ?-emission from 137Cs in dilute NaCl solutions. (author)

  15. Sodium carbonate as phase promoter in aqueous solutions of imidazolium and pyridinium ionic liquids

    International Nuclear Information System (INIS)

    Highlights: → The discovery of novel aqueous two-phase systems, exclusively formed by the mixture of an ionic liquid and sodium carbonate is presented. → We explore for the first time the ability of pyridinium-based ionic liquids to form aqueous biphasic systems. → A first advance of the benefits of using benzylimidazolium-based ionic liquids for aqueous two-phase systems is proposed. - Abstract: Several methylsulfate and chloride anion-based ionic liquids, such as 1-alkyl-3-methyl imidazolium methyl sulfate, CnMIM CH3SO4 (n = 1, 2, and 4), 1-benzyl-3-methyl imidazolium methyl sulfate, BzMIM CH3SO4, 1-benzyl, or hexyl-3-methyl imidazolium chloride, XMIM Cl (X = Bz and Hx), and methylpyridinium methylsulfate, Mpy CH3SO4, with sodium carbonate, Na2CO3, as phase forming salt, have been investigated and discussed for their potential use in separations based on aqueous two-phase systems (ATPS). Phase diagrams have been experimentally ascertained at T = 298.15 K, and Merchuck equation and a variation of this model have been used for correlating the binodal data. The alkyl chain length in the cation and the type of anion and cation have been explored and discussed due to their decisive influence in the ATPS behavior. The consistence of tie-line data was ascertained by applying the Othmer-Tobias and Bancroft equations.

  16. Comparison of two cathartic preparations, peg-electrolytes solution and sodium phosphate salts, as means for large bowel preparation for colonoscopy

    Directory of Open Access Journals (Sweden)

    N. Antonakopoulos, I. Kyrlagkitsis, V. Xourgias, D.G. Karamanolis

    2007-03-01

    Full Text Available SUMMARY The ideal bowel preparation for colonoscopy must combine the characteristics of effectiveness with the least side effects. We compared the relatively novel cathartic preparation of sodium phosphate salts (Fleet Phospho-sodaR with the widely used PEG-electrolytes solution (Klean-prepR. Fiftytwo consecutive patients referred for colonoscopy were randomised to receive either sodium phospate salts or PEG electrolytes. The evaluation of the two preparations was based on two separate questionnaires, one completed by the endoscopist who ignored the kind of bowel preparation used and the other by the patient. Bowel preparation with sodium phospate salts was more effective in bowel cleansing and better tolerated than PEG-electrolytes solution in terms of difficulty in intake and swallowing, fatigue, the presence of colicky abdominal pain, flatulence, vomiting and perianal irritation (p<0,05. Key words: cathartic preparation, PEG-electrolytes, sodium phosphate salts

  17. Attenuation coefficients of 123 keV ?-radiation by dilute solutions of sodium chloride

    International Nuclear Information System (INIS)

    The linear attenuation and mass attenuation (or absorption) coefficients of the 123 keV ? radiation from 57Co by dilute solutions of NaCl were studied for varying concentrations. The mixture rule for the theoretical calculation of attenuation coefficients was developed for solutions. This study explores the validity of the expected exponential attenuation absorption law for ?-radiation in solutions and also provides an alternative method for the direct determination of linear and mass attenuation coefficients of soluble salts in solid form without obtaining them in pure crystalline form. (Author)

  18. Corrosion protection of aluminium pretreated by vinyltriethoxysilane in sodium chloride solution

    International Nuclear Information System (INIS)

    The corrosion protection of vinyltriethoxysilane (VTES) films on aluminium during exposure to 3% NaCl was investigated using electrochemical impedance spectroscopy (EIS), potential-time measurements and optical microscopy coupled with image analysis. Composition and thickness of films were analyzed using Auger electron spectroscopy (AES) combined with depth profiling. It was shown that films deposited from 5% solution were significantly thicker and exhibited lower porosity and better corrosion stability, as compared to films deposited from 2 vol.% solution. VTES films deposited from 5 vol.% solutions and cured for 30 min exhibited better protection properties than other investigated films.

  19. Sodium Sulfate Separation from Aqueous Alkaline Solutions via Crystalline Urea-Functionalized Capsules: Thermodynamics and Kinetics of Crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Custelcean, Radu [ORNL; Sloop Jr, Frederick {Fred} V [ORNL; Rajbanshi, Arbin [ORNL; Wan, Shun [ORNL; Moyer, Bruce A [ORNL

    2015-01-01

    ABSTRACT: The thermodynamics and kinetics of crystallization of sodium sulfate with a tripodal tris-urea receptor (L1) from aqueous alkaline solutions have been measured in the 15 55 C temperature range, with the goal of identifying the optimal conditions for efficient and quick sulfate removal from nuclear wastes. The use of radiolabeled Na235SO4 provided a practical way to monitor the sulfate concentration in solution by liquid scintillation counting. Our results are consistent with a two-step crystallization mechanism, involving relatively quick dissolution of crystalline L1 followed by the rate-limiting crystallization of the Na2SO4(L1)2(H2O)4 capsules. We found that temperature exerted relatively little influence over the equilibrium sulfate concentration, which ranged between 0.004 and 0.011 M. This corresponds to 77 91% removal of sulfate from a solution containing 0.0475 M initial sulfate concentration, as found in a typical Hanford waste tank. The apparent pseudo-first-order rate constant for sulfate removal increased 20-fold from 15 to 55 C, corresponding to an activation energy of 14.1 kcal/mol. At the highest measured temperature of 55 C, 63% and 75% of sulfate was removed from solution within 8 h and 24 h, respectively.

  20. Interactions of glutamine dipeptides with sodium dodecyl sulfate in aqueous solution measured by volume, conductivity, and fluorescence spectra

    International Nuclear Information System (INIS)

    Highlights: ? Ion-ion and ion-polar group interactions are dominant interactions. ? The SDS addition and temperature increase cause a dehydration effect on dipeptides. ? The addition of dipeptide in water decreases the ccmc of SDS. ? Enthalpy-entropy compensation takes place during micellization. ? Micelle aggregation number was decreased by addition of glutamine dipeptides. - Abstract: Densities, conductivities, and fluorescence spectra of {sodium dodecyl sulfate (SDS) + glutamine dipeptide + water} mixtures were measured as a function of temperature. The density data have been utilized to calculate apparent molar volumes, standard partial molar volumes (V2,?o), standard partial molar volumes of transfer from water to aqueous SDS solutions (?tVo), the hydration number, partial molar expansibility (E?o), and Hepler's constant of glutamine dipeptides. The critical micellar concentration (ccmc) and the degree of counterion dissociation of SDS micelles obtained from electrical conductivity data have been estimated at various concentrations of glutamine dipeptide. Thermodynamic parameters of micellization of SDS in aqueous dipeptide solutions have been determined from ccmc values and an enthalpy-entropy compensation effect was observed for the ternary systems. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interaction of SDS with glutamine dipeptide, and the aggregation behavior of SDS. The results have been interpreted in terms of solute-solvent interactions and structural changes in the mixed solutions.

  1. Effects of hypertonic sodium chloride solution on the electrophysiologic alterations caused by bupivacaine in the dog heart

    Directory of Open Access Journals (Sweden)

    Scalabrini A.

    2003-01-01

    Full Text Available The effects of various hypertonic solutions on the intraventricular conduction, ventricular repolarization and the arrhythmias caused by the intravenous (iv injection of bupivacaine (6.5 mg/kg were studied in sodium pentobarbital-anesthetized mongrel dogs. Hypertonic solutions, given iv 5 min before bupivacaine, were 7.5% (w/v NaCl, 5.4% (w/v LiCl, 50% (w/v glucose (2,400 mOsm/l, 5 ml/kg, or 20% (w/v mannitol (1,200 mOsm/l, 10 ml/kg. Bupivacaine induced severe arrhythmias and ventricular conduction and repolarization disturbances, as reflected by significant increases in QRS complex duration, HV interval, IV interval and monophasic action potential duration, as well as severe hemodynamic impairment. Significant prevention against ventricular electrophysiologic and hemodynamic disturbances and ventricular arrhythmias was observed with 7.5% NaCl (percent increase in QRS complex duration: 164.4 ± 21.8% in the non-pretreated group vs 74.7 ± 14.1% in the pretreated group, P<0.05; percent increase in HV interval: 131.4 ± 16.1% in the non-pretreated group vs 58.2 ± 7.5% in the pretreated group, P<0.05; percent increase in monophasic action potential duration: 22.7 ± 6.8% in the non-pretreated group vs 9.8 ± 6.3% in the pretreated group, P<0.05; percent decrease in cardiac index: -46 ± 6% in the non-pretreated group vs -28 ± 5% in the pretreated group, P<0.05. The other three hypertonic solutions were ineffective. These findings suggest an involvement of sodium ions in the mechanism of hypertonic protection.

  2. A study of the structure of mixed micellar solutions based on heptaethylene glycol monotetradecyl ether and sodium (lithium) dodecyl sulfate by the small-angle neutron scattering method

    International Nuclear Information System (INIS)

    The micellization in mixed aqueous systems based on a new nonionic surfactant, namely, heptaethylene glycol monotetradecyl ether (C14E7), and an anionic surfactant, namely, sodium dodecyl sulfate, sodium decyl sulfate, or lithium dodecyl sulfate, is studied by small-angle neutron scattering. Preliminary results of the investigation into the behavior of C14E7 aqueous solutions (at two concentrations, 0.17 and 0.50%) upon addition of small amounts of three different classical anionic surfactants are reported

  3. Comparison of the Antibacterial Effect of Sodium Hypochlorite and Aloe Vera Solutions as Root Canal Irrigants in Human Extracted Teeth Contaminated with Enterococcus Faecalis

    OpenAIRE

    Sahebi S.; Khosravifar N.; SedighShamsi M.; Motamedifar M.

    2014-01-01

    Statement of Problem: The main purpose of a root canal treatment is to eliminate the bacteria and their products from the pulp space. Sodium hypochlorite has excellent antibacterial properties but also some negative features. Purpose: The aim of the present study is to compare the antimicrobial effect of Aloe Vera solution with sodium hypochlorite on E.faecalis in the root canals of human extracted teeth. Materials and Method: Sixty human extracted single rooted teeth were selected for...

  4. Low temperature fatigue behavior of Alloy 600 in sodium chloride solution

    International Nuclear Information System (INIS)

    Fatigue crack growth (FCG) rates of mill annealed Alloy 600 in NaCl solution were studied by a fracture mechanics test method. Compact tension (CT) specimens were tested under load control with a sinusoidal wave form, in accordance with ASTM specification E647-83, to investigate the effects of environment, load frequency (f), load ratio (R = Pmin/Pmax). The FCG rates of Alloy 600, R = 0.1, f = 1Hz, were quite similar in air, distilled water, and NaCl (0.6M, 0.1M, and 0.001M) solution at room temperature. Environmental enhancement effect on the FCG rate of Alloy 600 was not significant in NaCl solution. Variations of the load frequency (0.03Hz--3Hz) did not influence the FCG rates of Alloy 600 significantly in air and 0.1M NaCl solution. The FCG rates of Alloy 600 in air and 0.1M NaCl solution increased with increasing the load ratio. Compared with the corrosion effects, test results showed that the mechanical effects dominated on the FCG rates of Alloy 600 in chloride solution at room temperature. The SEM fractographs showed that significant striations and transgranular fracture modes were observed on tested specimens

  5. The reduction of sodium pertechnetate [99mTc] in hydrochloric acid solution

    International Nuclear Information System (INIS)

    Full text: The preparation of 99mTc-radiopharmaceuticals by exchange reactions of 99mTc chloro complexes is attractive, since there is the potential for a better control of the oxidation state of 99mTc than by the reduction of pertechnetate [99mTc] by stannous chloride. Reflux of 'carrier free' sodium pertechnetate[99mTc] in 12 M HCl, evaporation to dryness, and electrophoresis in 1 M p-toluene-sulphonic acid (Hpts) showed that the [99mTcCl6]2- initially formed is readily oxidised to 99mTcO4-, but there is also a more stable species with lower anionic migration present. Studies with 99mTc indicated that this species is [99mTcCl5(OH2)]-. Reflux of pertechnetate [99mTc]/HCl in the presence of sodium azide, evaporation to dryness and electrophoresis in 0.5 M Hpts showed the presence of a single cationic species, together with some 99mTcO4-. Studies with 99mTc showed that the cationic species is the m-oxo dimer [99mTcN(OH2)3(? -O)299mTcN(OH2)3]2+, where a nitrogen atom is attached to 99mTc (in the +6 oxidation state) by a triple bond. The cationic species is stable and may be used to prepare a variety of 99mTcN-radiopharmaceuticals. Reflux of pertechnetate [99mTc]/HCl in the presence of a wide range of nitrogen compounds (e.g. hydrazine) resulted in a complex mixture of 99mTc products, including 99mTcO4-, an anionic species, a peak near the origin, and one, two or three cationic species. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  6. A method of calculating quartz solubilities in aqueous sodium chloride solutions

    Science.gov (United States)

    Fournier, R.O.

    1983-01-01

    The aqueous silica species that form when quartz dissolves in water or saline solutions are hydrated. Therefore, the amount of quartz that will dissolve at a given temperature is influenced by the prevailing activity of water. Using a standard state in which there are 1,000 g of water (55.51 moles) per 1,000 cm3 of solution allows activity of water in a NaCl solution at high temperature to be closely approximated by the effective density of water, pe, in that solution, i.e. the product of the density of the NaCl solution times the weight fraction of water in the solution, corrected for the amount of water strongly bound to aqueous silica and Na+ as water of hydration. Generally, the hydration of water correction is negligible. The solubility of quartz in pure water is well known over a large temperature-pressure range. An empirical formula expresses that solubility in terms of temperature and density of water and thus takes care of activity coefficient and pressure-effect terms. Solubilities of quartz in NaCl solutions can be calculated by using that equation and substituting pe, for the density of pure water. Calculated and experimentally determined quartz solubilities in NaCl solutions show excellent agreement when the experiments were carried out in non-reactive platinum, gold, or gold plus titanium containers. Reactive metal containers generally yield dissolved silica concentrations higher than calculated, probably because of the formation of metal chlorides plus NaOH and H2. In the absence of NaOH there appears to be no detectable silica complexing in NaCl solutions, and the variation in quartz solubility with NaCl concentration at constant temperature can be accounted for entirely by variations in the activity of water. The average hydration number per molecule of dissolved SiO2 in liquid water and NaCl solutions decreases from about 2.4 at 200??C to about 2.1 at 350??C. This suggests that H4SiO4 may be the dominant aqueous silica species at 350??C, but other polymeric forms become important at lower temperatures. ?? 1983.

  7. Efeito do bicarbonato de sódio no tratamento de vinhaça em AnSBBR operado a 55 e 35ºC / Effect of the sodium bicarbonate in the treatment of vinasse in AnSBBR operated at 55 and 35ºC

    Scientific Electronic Library Online (English)

    Maria Magdalena Ribas, Döll; Eugenio, Foresti.

    2010-09-01

    Full Text Available Avaliou-se a influência do bicarbonato de sódio (NaHCO3) no desempenho do reator anaeróbio batelada sequencial com biomassa imobilizada tratando vinhaça a 55 e a 35ºC. O reator foi preenchido com espuma de poliuretano e agitado a 300 rpm. A adaptação a 55ºC estendeu-se por 50 dias, tendo o reator si [...] do alimentado com vinhaça (DQO de 0,3 a 1,0 g/L). Para a operação a 35ºC, procedeu-se inicialmente ao enriquecimento da população metanogênica, durante 21 dias, com substrato à base de etanol (2,5 gDQO/L). Posteriormente, cargas orgânicas volumétricas (COV) de 0,85 a 5,70 gDQO/L.d foram aplicadas no reator a 55ºC, com suplementação de 1,2 a 0,4 gHCO3-/gDQO. A 35ºC, o reator foi submetido a COV de 2,85 a 36,0 gDQO/L.d com 0,4 a 0,2 gHCO3-/gDQO. A remoção de DQO variou de 43 a 78% a 55ºC e de 75 a 85% a 35ºC. A suplementação de alcalinidade mostrou-se essencial para a estabilidade do processo, sendo requerida em menor quantidade a 35ºC. Abstract in english The influence of the sodium bicarbonate (NaHCO3) on the performance of an anaerobic sequencing batch biofilm reactor treating vinasse at 55 and 35ºC was evaluated. The reactor was filled with polyurethane foam and agitated at 300 rpm. The acclimatization period at 55ºC lasted 50 days, and the reacto [...] r was fed with vinasse (COD from 0.3 to 1.0 g/L). A previous enrichment of methanogenic population was provided for the reactor operated at 35ºC, feeding it with an ethanol based substrate (2.5 gCOD/L) during 21 days. Further on, organic loading rates (OLR) ranging from 0.85 to 5.70 gCOD/L.d were applied to the reactor at 55ºC, supplemented with 1.2 to 0.4 gHCO3-/gCOD. At 35ºC the reactor was subjected to OLR ranging from 2.85 to 36.0 gCOD/L.d with 0.4 to 0.2 gHCO3-/gCOD. COD removal ranged from 43 to 78% at 55ºC and from 75 to 85% at 35ºC. Alkalinity supplementation was found to be essential for process stability, but the amount required was lower at 35ºC.

  8. Efeito do bicarbonato de sódio no tratamento de vinhaça em AnSBBR operado a 55 e 35ºC Effect of the sodium bicarbonate in the treatment of vinasse in AnSBBR operated at 55 and 35ºC

    Directory of Open Access Journals (Sweden)

    Maria Magdalena Ribas Döll

    2010-09-01

    Full Text Available Avaliou-se a influência do bicarbonato de sódio (NaHCO3 no desempenho do reator anaeróbio batelada sequencial com biomassa imobilizada tratando vinhaça a 55 e a 35ºC. O reator foi preenchido com espuma de poliuretano e agitado a 300 rpm. A adaptação a 55ºC estendeu-se por 50 dias, tendo o reator sido alimentado com vinhaça (DQO de 0,3 a 1,0 g/L. Para a operação a 35ºC, procedeu-se inicialmente ao enriquecimento da população metanogênica, durante 21 dias, com substrato à base de etanol (2,5 gDQO/L. Posteriormente, cargas orgânicas volumétricas (COV de 0,85 a 5,70 gDQO/L.d foram aplicadas no reator a 55ºC, com suplementação de 1,2 a 0,4 gHCO3-/gDQO. A 35ºC, o reator foi submetido a COV de 2,85 a 36,0 gDQO/L.d com 0,4 a 0,2 gHCO3-/gDQO. A remoção de DQO variou de 43 a 78% a 55ºC e de 75 a 85% a 35ºC. A suplementação de alcalinidade mostrou-se essencial para a estabilidade do processo, sendo requerida em menor quantidade a 35ºC.The influence of the sodium bicarbonate (NaHCO3 on the performance of an anaerobic sequencing batch biofilm reactor treating vinasse at 55 and 35ºC was evaluated. The reactor was filled with polyurethane foam and agitated at 300 rpm. The acclimatization period at 55ºC lasted 50 days, and the reactor was fed with vinasse (COD from 0.3 to 1.0 g/L. A previous enrichment of methanogenic population was provided for the reactor operated at 35ºC, feeding it with an ethanol based substrate (2.5 gCOD/L during 21 days. Further on, organic loading rates (OLR ranging from 0.85 to 5.70 gCOD/L.d were applied to the reactor at 55ºC, supplemented with 1.2 to 0.4 gHCO3-/gCOD. At 35ºC the reactor was subjected to OLR ranging from 2.85 to 36.0 gCOD/L.d with 0.4 to 0.2 gHCO3-/gCOD. COD removal ranged from 43 to 78% at 55ºC and from 75 to 85% at 35ºC. Alkalinity supplementation was found to be essential for process stability, but the amount required was lower at 35ºC.

  9. Influence of chloride, carbonate an bicarbonate ions on pitting corrosion of stainless steels

    International Nuclear Information System (INIS)

    Inhibition of pitting corrosion of stainless steels Z3CN 18-10(304L) and Z8CNDT 17-12 (316Ti) by carbonate or bicarbonate ions in a chloride solution is studied by potentio-kinetic voltametry. Results show that inhibition by CO3-- and HCO3- occurs when ion activity is greater than the value obtained by the equation log (Cl-) = A + B log (I) showing a competition between adsorption of Cl- and CO3-- ions. Carbonate is more efficient than bicarbonate for tested steels

  10. Migration behaviour of 14C labelled bicarbonate, HTO and 131I in boom clay

    International Nuclear Information System (INIS)

    Performance assessment studies for the deep geological disposal of radioactive waste in the Boom clay indicated the importance of the radionuclides 14C and 129I. The migration properties of these radionuclides in Boom clay are studied by Flow-Through type diffusion experiments. In the diffusion tests a mixture of 14C labelled bicarbonate, tritiated water (HTO) and carrier free 131C labelled bicarbonate, tritiated water (HTO) and carrier free 131I sodium iodide (NaI) is used. The isotope 131I is used as an equivalent for 129I. The mixture allows for a good comparison of the migration behviour of the three different species. The mean value of the diffussion constant for bicarbonate is 1.8x10-6, for iodide 4.2x10-6 and for tritiated water 6.2x10-6 cm2.s-1. For the interpretation of the experiments we consider sorption (isotopic exchange), diffusion and first order chemical reaction. The results of the diffusion tests are consistent with the concept of the diffusion accessible porosity and proves the importance of this concept. The diffusion accessible porosity for both bicarbonate and iodide is 0.11. The results are important for the safety assessment of a radioactive waste repository in the clay formation. (orig.)

  11. One-step synthesis of silica-coated magnetite nanoparticles by electrooxidation of iron in sodium silicate solution

    International Nuclear Information System (INIS)

    Silica-coated magnetite nanoparticles have been synthesized successfully using a one-step electrochemical method. In this method, pure iron in a dilute aqueous sodium silicate solution that served as a silica precursor was electrooxidized. We show that the presence of silicate can significantly enhance the purity of the magnetite formed. Impurities in the form of FeOOH (found in the magnetite prepared in water) are not found. The magnetite nanoparticles produced by this method are nearly spherical with a mean size ranging from 6 to 10 nm, which is lower than the size of particles prepared in water, and this size range depends on the applied voltage and the sodium silicate concentration. The magnetite nanoparticles exhibit superparamagnetic properties with saturation magnetization ranging from 15 to 22 emu g?1, which is lower than the saturation magnetization of the Fe3O4 bulk materials (Ms = 92 emu g?1). This facile method appears to be promising as a synthetic route for producing silica-coated magnetite nanoparticles.

  12. The interaction of phosphate coatings on a carbon steel surface with a sodium nitrite and silicate solution

    Science.gov (United States)

    Ramanauskas, R.; Girčienė, O.; Gudavičiūtė, L.; Selskis, A.

    2015-02-01

    Mono-cation PZn, bi-cation PZnCa, PZnNi and three-cation PZnNiMn crystalline phosphate coatings were modified with an inhibitor mixture: a sodium nitrite and sodium silicate solution with the aim to establish the reasons of protective ability enhancement of passive films on a carbon steel surface in an alkaline media. The SEM, EDS, XRD and XPS techniques were applied for the structural, phase and composition characterization of the phosphate coatings, voltammetric measurements were carried out to determine the passive layer protective ability, while EIS studies yielded information on the coatings porosity. Compact films of Si compounds were formed on the surface of the phosphate coatings during their modification procedure, which was accompanied by an increase in the protective ability of phosphate layer. A higher porosity and regularly shaped crystallites of the phosphate layer were favourable for accumulation of a greater amount of Si in the modified coatings. The protective ability of the modified coatings remains fairly pronounced, which testifies that the phosphate layer porosity is not the only factor influencing the corrosion behaviour of the coating. The difference in the nature of Si compounds comprising modified phosphate coatings leads to the differences in their protective ability.

  13. High resolution 1H NMR study of the solution structure of the S4 segment of the sodium channel protein

    International Nuclear Information System (INIS)

    In this work the authors assessed the models of S4 by synthesizing the S4 segment of the first internal repeat of the rat brain I and II sodium channels and examining its solution conformation by high-resolution NMR. The authors synthesized the sequence proposed for S4 by Noda et al. With lysine as the 21 st and final residue. The results indicate that the synthetic peptide, corresponding to the S4 sequenceproposed for the internal repeat of the rat brain sodium channel by Noda et al. Forms a predominantly ?-helical structure in TFE/wter (9:1); there is no evidence for a 310 helix as has been suggested. Since the basic residues are evenly disposed about the helix face, the structural data are consistent with the 'sliding helix' model of channel activation, but the closely related ion-pair disruption model of Greenblatt et al is still a possibility. The methodology presented here, which involves synthesis of a putative membrane-spanning helix and the determination of its structure in an organic solvent by high resolution NMR and computer based methods, promises to be a powerful way of gaining new information about membrane proteins consisting of helical bundles. It has been pointed out that the usual structure prdiciton methods may not be an ideal way of producing models of these proteins. (author). 20 refs.; 3 figs.; 2 tabs

  14. Some magnetic resonance properties of solutions of sodium in liquid ammonia; Contribution a l'etude des solutions de sodium dans l'ammoniac liquide par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-02-01

    Dilute solutions of sodium in liquid ammonia are studied by the mean of dynamic polarization techniques, and with the aid of Becker Lindquist and Alder model. Paramagnetic shifts are computed as a function of the 'average spin density', for each of the nuclear spin system. The nuclear contributions to the Overhauser shift are computed in the same way. A theoretical study of the main relaxation processes is carried out for each of the nuclear spin system and for the electronic spin system. The dynamic polarization experiments consist in classical measurement of the Overhauser enhancement for nitrogen, and in direct measurements of nitrogen Knight shift and nuclear contributions to the Overhauser shift by the mean of double irradiation techniques. The results show that, in dilute solutions, the relaxation of nitrogen arises from quadrupole interaction and from hyperfine interaction with unpaired electrons. Both interactions are of the same order of magnitude. Overhauser shift measurements show that the spin density is negative at the proton site, in agreement with Hughes results. (author) [French] Les solutions diluees de sodium dans l'ammoniac sont etudiees au moyen des techniques de la polarisation dynamique, sur la base du modele de Becker Lindquist et Aider. Les deplacements paramagnetiques des raies de resonance nucleaire des differents noyaux sont analyses en faisant appel a la notion de ''densite moyenne de spin'' introduite par l'auteur; et les differentes contributions nucleaires au deplacement d'Overhauser sont calculees en fonction de cette meme grandeur. Une etude theorique de la relaxation de chaque systeme de spin permet d'evaluer l'importance relative des differents mecanismes mis en jeu. Les experiences de polarisation dynamique effectuees au cours de ce travail consistent en mesures classiques de l'effet Overhauser sur l'azote, d'une part, et en la mise en oeuvre de techniques originales pour mesurer le deplacement de Knight de l'azote et les differentes contributions au deplacement d'Overhauser, d'autre part. Les resultats obtenus montrent, en particulier, que la relaxation de l'azote, dans les solutions diluees, est due, a parts sensiblement egales, a l'interaction quadrupolaire et a l'interaction scalaire avec les electrons non apparies. Les mesures du deplacement d'Overhauser du aux protons montrent que la densite de spin sur ces noyaux est negative et confirment ainsi les travaux de Hughes. (auteur)

  15. Radiolysis of concentrated solutions of sodium nitrate in D2O

    International Nuclear Information System (INIS)

    Results are presented from a comparative investigation of the radiolysis of concentrated solutions of NaNO3 in D2O under the effect of 60Co ?-rays and 14.1-MeV fast neutrons. It was shown that, just as for solutions based on H2O, The yields of NO2- by the indirect-action mechanism depend little on the type of radiation. At the same time, in neutron irradiation, the yield by the direct-action mechanism is twice as great as in ?-radiolysis. Pulsed radiolysis was used to measure the rate constant of the reaction of a solvated electron with the NO3minus ion in D2O. The determined value of kD2O, (5.1 ± 0.7) x 109 dm3/(molexsec), was found to be almost twofold less than the analogous value for solutions in light water

  16. AFM study of the early corrosion of a high strength steel in a diluted sodium chloride solution

    International Nuclear Information System (INIS)

    The high strength steels employed as reinforcement in pre-stressed concrete structures are drawn wire steels of eutectoid composition with a pearlitic microstructure. This work is focused on the study, by atomic force microscopy, of the early stages of the corrosion of such steels as a consequence of their exposition to a sodium chloride solution. The obtained images show the pearlitic microstructure of the steel, with a preferential attack of the ferrite phase and the cementite acting as a cathode. The corrosion rate was determined by calculating the amount of material lost from a roughness analysis. The obtained results are in good agreement with the predictions of Galvelel's theory, according to which the corrosion rate slows down as the pit depth increases

  17. Experimental investigation of aluminum complexing with sodium ion and of gallium and iron (III) speciation in natural solutions

    International Nuclear Information System (INIS)

    The aim of this work is to acquire thermodynamic data on the aqueous complexes forming between sodium and aluminum, gallium and hydroxide, and iron (III) and hydroxide. These data will provide for a better understanding of the transport and distribution of these elements in surface and hydrothermal fluids. Stability constants of the sodium-aluminate complex (Na Al(OH)4 deg.) were obtained from boehmite solubility measurements at temperatures from 125 to 350 deg. C in alkaline solutions containing from 0.1 to 1 mol/L sodium. Complementary potentiometric measurements were performed with a sodium selective electrode, between 75 and 200 deg C (the potentiometric study was carried out by Gleb Pokrovski). Analyses of these data within the framework of the revised Helgeson-Kirkham-Flowers (HKF) model allowed determination of the HKF parameters for Na Al(OH)4 deg. and calculation of its thermodynamic properties to 800 deg. C and 5 kb. The results of this work show that Na Al(OH)4 deg. complex formation increases significantly the solubility of aluminum-bearing minerals and consequently aluminum mobility in hydrothermal fluids. Gallium speciation in surface and hydrothermal fluids is dominated by the negatively charged species, Ga(OH)4-. The thermodynamic properties of this species were determined from of OEGaOOH solubility measurements as a function of pH and temperature from 25 to 250 deg. C. In general, the variation of gallium aqueous speciation with pH is similar to that of aluminum other than at temperatures less than 200 deg. C over the pH range 3 - 6. This difference can account for the independent behavior of gallium versus aluminum in numerous low temperature natural systems. The thermodynamic properties of Fe(OH)3 deg. which dominates the speciation of Fe(III) in surface waters and Fe(OH)4- were determined from hematite solubility measurements as a function of pH, oxygen pressure and temperature from 110 to 300 deg. C. The available thermodynamic data on other aqueous iron (II) and iron (III) hydroxide complexes and solid iron (III) oxides and hydroxides were re-examined. A coherent set of thermodynamic data for the minerals and aqueous species in the system Fe(III)-O-H was generated in this study. These resulting data allows accurate calculation of the solubility of iron (III) oxides and hydroxides as a function of pH, specific surface area, and aging time (for amorphous hydroxide). (author)

  18. Study on Corrosion Performance of Cu-Te-Se Alloys in a 3.5% Sodium Chloride Solution

    Science.gov (United States)

    Jiao, Lin; Li, Meng; Zeng, Tao; Zhu, Dachuan

    2015-11-01

    Samples of Cu-Te-Se alloys, previously aged or treated as a solid solution, were immersed in 3.5% (mass fraction) sodium chloride solution to investigate their corrosion resistance at room temperature by determining their corrosive weight loss. The morphologies of the precipitated phase and surface products following immersion were observed by scanning electron microscope. In addition, energy-dispersive spectroscopic analysis was used to determine the elemental constituents of precipitated phase and corroded surface of the alloy samples. The phase composition was measured by x-ray diffraction, and the electrochemical polarization behavior of the samples was determined using an electrochemical workstation. The experimental results revealed that the alloy samples appeared to corrode uniformly, which was accompanied by a small amount of localized corrosion. There was the possibility that localized corrosion could increase following aging treatment. The addition of a small amount of tellurium and selenium to the alloy appeared to retard oxygen adsorption on the copper in the alloy, which has ameliorated the alloy corrosion due to the similar physical and chemical properties of oxygen. In comparison to the solid solution state, the corrosion resistance of the alloy appeared to decline slightly following aging treatment.

  19. In vitro study of triglyceride lipolysis and phase distribution of the reaction products and cholesterol: effects of calcium and bicarbonate

    OpenAIRE

    Vinarov, Z.; Petrova, L.; Tcholakova, S.; Denkov, N. D.; Stoyanov, S.D.; Lips, A.

    2012-01-01

    We describe a relatively simple in vitro model for triglyceride (TG) lipolysis which mimics closely the conditions in the human stomach and small intestine. The main model advantages are: (1) as in vivo, sodium bicarbonate is used for buffering; (2) the pH-profile in the small intestine is closely matched; (3) the experimental procedure does not include complex equipment. To test its performance, the proposed in vitro model is applied to quantify the effects of Ca2+, pH, and bicarbonate on th...

  20. Reappraisal of bicarbonate secretion by the human oesophagus

    DEFF Research Database (Denmark)

    Mertz-Nielsen, A; Hillingsø, J; Bukhave, Klaus; Rask-Madsen, J

    1997-01-01

    BACKGROUND AND AIMS: Administration of omeprazole to healthy volunteers was recently reported to increase proximal duodenal mucosalbicarbonate secretion. As human oesophagus also secretes bicarbonate, the hypothesis was tested that omeprazole may stimulate oesophagealbicarbonate secretion and thus...... median rates (95% confidence intervals)of intrinsic oesophageal bicarbonate secretion, corrected for contaminating salivary and gastric bicarbonate, were 89 (33-150) and 121 (63-203)mumol/h/10 cm (p > 0.5) in omeprazole and ranitidine treated subjects respectively. Salivary and gastric bicarbonate...... overestimated. As omeprazole and ranitidine did not affect bicarbonate secretion differently there was no evidence that omeprazole acts on icarbonate secretory cells in the oesophageal mucosa....

  1. Red phosphorus oxidation by oxygen in alcohol solution of iodine and sodium nitrite

    International Nuclear Information System (INIS)

    Red phosphorous is oxidized rapidly by oxygen at 50-70 deg C into tri-and dialkyl phosphates in the alcohol solution of I2 and NaNO2. The kinetics and mechanism are studied, optimal conditions of a new catalytic reaction are found. 48 refs.; 4 figs

  2. Determination of degraded products of TBP in the sodium carbonate waste solutions of PUREX process

    International Nuclear Information System (INIS)

    PUREX process is widely employed for reprocessing of spent nuclear fuel using dilute TBP (30% Tributyl phosphate-70% normal paraffin hydrocarbon). During the course of its use, the PUREX solvent undergoes chemical and radiolytic degradation. Major degradation product is dibutyl phosphate (DBP). To purify the solvent from degraded products, sodium carbonate wash treatment is applied periodically. The resultant carbonate wash waste falls under the category of Intermediate Level radioactive liquid Waste (ILW). During the conventional IX treatment of this ILW it was observed that at the carbonate destruction step the DBP in the waste is forming a sticky and difficult to handle yellow mass with the uranyl ions. Major portion of alpha and some amount of beta activity are associated with this sticky mass. Alternate method of direct cementation/polymerization and disposal in the NSDF is not possible for this ILW due to the presence of high alpha activity. Hence remediation of this ILW prior to IX treatment was tried and various schemes were developed at different laboratories. A new treatment scheme involving partial carbonate destruction followed by alkali precipitation of uranyl ions was worked out in our laboratory. Present work details the analysis of degraded products of TBP in different streams of the new treatment scheme

  3. Uranium release from boom clay in bicarbonate media

    International Nuclear Information System (INIS)

    The release of natural uranium from Boom Clay was studied to better understand the mechanisms governing the solid-liquid partitioning of uranium. Batch leaching experiments suggested that the portion of natural uranium released from clay is associated with colloids at a low bicarbonate concentration prevailing in Boom Clay. At increased bicarbonate concentrations, uranium was present predominantly as dissolved species indicating a formation of uranium carbonate complexes. The in situ aqueous uranium concentration, i.e., the concentration in the pore waters collected by piezometers was found to be 2 to 3 orders of magnitudes lower than the one measured by the batch techniques. These results illustrated that the batch techniques may cause a remobilization of uranium containing colloids from clay surfaces into solution when clay is suspended, agitated, and mechanically perturbed. These colloids are attributed to artefacts and are not considered to exist in situ because of the high compaction of Boom Clay. Due to the presence of colloids, a laboratory derived solid-liquid partitioning coefficient is not equivalent to and cannot simply be converted to the distribution coefficient Kd currently used in performance assessment calculations. (orig.)

  4. Evaluation of Perrhenate Spectrophotometric Methods in Bicarbonate and Nitrate Media.

    Science.gov (United States)

    Lenell, Brian A; Arai, Yuji

    2016-04-01

    2-pyridyl thiourea and methyl-2-pyridyl ketoxime based perrhenate, Re(VII), UV-vis spectrophotometric methods were evaluated in nitrate and bicarbonate solutions ranging from 0.001M to 0.5M. Standard curves at [Re]=2.5-50mgL(-1) for the Re(IV)-thiourea and the Re ketoxime complexes were constructed at 405nm and 490nm, respectively. Detection of limits for N-(2-pyridyl) thiourea and methyl-2-pyridyl ketoxime methods in ultrapure water are 3.06mg/L and 4.03mg/L, respectively. Influences of NaHCO3 and NaNO3 concentration on absorbance spectra, absorptivity, and linearity were documented. For both methods, samples in ultrapure water and NaHCO3 have an R(2) value>0.99, indicating strong linear relationships. Statistical analysis supports that NaHCO3 does not affect linearity between standards for either method. NaNO3 causes major interference with the ketoxime method above 0.001M NaNO3. Data provides information for practical use of Re spectrophotometric methods in environmental media that is high in bicarbonate and nitrate. PMID:26838460

  5. Inhibiting effect of acetonitrile on oxygen reduction on polycrystalline pt electrode in sodium chloride solution

    Directory of Open Access Journals (Sweden)

    Marinovi? Vedrana M.

    2012-01-01

    Full Text Available The oxygen reduction reaction (ORR was studied on the polycrystalline Pt electrode in 0.1 M NaCl electrolyte containing various amounts of acetonitrile (AcN. The state of the electrode surface was characterized by the cyclic voltammetry in oxygen free electrolytes, while ORR studies were performed on the polycrystalline Pt rotating disc electrode by the linear sweep voltammetry in oxygen saturated electrolytes. The acetonitrile is chemisorbed on Pt over a wide potential range, inhibiting both hydrogen adsorption and oxide formation. The extent of AcN chemisorption depends on its concentration in the solution. Initial potential of oxygen reduction is shifted negatively, while the ORR current is increasingly reduced with the increase of AcN concentration. Complete inhibition of ORR in the potential range of AcN and Cl-anion coadsorption is achieved for (0.1 M NaCl + 1 M AcN solution.

  6. Electrochemical Study of Corrosion Behavior of Wrought Stellite Alloys in Sodium Chloride and Green Death Solutions

    Science.gov (United States)

    Zhang, X. Z.; Liu, R.; Chen, K. Y.; Yao, M. X.; Collier, R.

    2015-09-01

    Corrosion behavior of wrought Stellite 6B and Stellite 6K, which have similar chemical composition but contain different carbon content, in 3.5 wt.% NaCl solution and in Green Death solution is investigated using various electrochemical methods, including potentiodynamic polarization, cyclic polarization, and electrochemical impedance spectroscopy (EIS). The obtained potentiodynamic polarization curves, cyclic polarization curves, and EIS spectra for these alloys are in good agreement, showing that Stellite 6K with higher carbon content is easier corroded due to its larger volume fraction of carbides but the Cr2O3 film formed on this alloy is stronger and more stable than that on Stellite 6B. Further immersion tests on these alloys show that Stellite 6K has less resistance to pitting corrosion.

  7. Effects of applied potential on the fatigue behavior of Alloy 600 in sodium chloride solution

    International Nuclear Information System (INIS)

    The fatigue crack growth (FCG) rates of mill annealed Alloy 600 in 0.1 M NaCl solution, 25 C, were studied by a fracture mechanics test method and were affected by the applied potential, load frequency and load ratio. At an applied cathodic potential of -1,300mVSCE, the FCG rates increased with lowering, the load frequency and with increasing the load ratio. The enhanced FCG rate was found in the lower load frequencies (?< 0.1 Hz) and was more significant with increasing the load ratio. The secondary cracks and transgranular fracture modes were observed on the fractured surfaces with applied cathodic potential. The possible hydrogen-assisted cracking mechanism on enhancing the FCG rates of Alloy 600 cathodically charged in 0.1 M NaCl solution, 25 C, is discussed in this paper. This study is pertinent to the fatigue cracking problems occurring in steam generator tubes of PWR

  8. Sodium chloride crystallization from drying drops of albumin-salt solutions with different albumin concentrations

    Science.gov (United States)

    Yakhno, T. A.

    2015-11-01

    The salt nature of crystalline structures resulting from drying albumin-salt solutions with a low (<1 wt %) and high (7 and 9 wt %) concentration of albumin and a NaCl concentration kept at a physiological level (0.9 wt %) is experimentally substantiated. Such a conclusion is drawn from the dynamics of phase transitions, morphological studies, and differences between the physicochemical properties of albumin and salt. Obtained data give a deeper insight into the albumin and salt distributions in drying liquids.

  9. Comparisons of fixation of heat, radiation, and heat plus radiation damage by anisotonic sodium chloride solutions

    International Nuclear Information System (INIS)

    Heat treatment at temperatures greater than 40 degrees C synergistically enhanced damage produced by ionizing radiation. Researchers experiments indicated that radiation damage in exponentially growing Chinese hamster cells could be fixed in a dose-dependent manner by postirradiation treatment with both hypertonic and hypotonic NaCl solutions. At a 1,000-rad dose level, survival could be depressed by a factor of about 260. For various treatments at either 42 or 45 degrees C, exposure after heating to anisotonic solutions did not result in the fixation of heat damage. When cells were heated at 45 degrees C for 5 minutes and irradiated with 500 rad before or after heating or given 500 rad without heating and then exposed to 0.05 M NaCl solutions for 120 minutes, survival was reduced by factors of 875, 667, and 12, respectively. For heat treatments at lower temperatures, such as 41.5 or 42 degrees C, less damage fixation for the combined treatments was observed. The data indicated that heat and radiation damage were different and damage from the combined treatments was not the same for low- and high-treatment temperatures

  10. Comparisons of fixation of heat, radiation, and heat plus radiation damage by anisotonic sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Raaphorst, G.P.; Azzam, E.I.

    1982-06-01

    Heat treatment at temperatures greater than 40 degrees C synergistically enhanced damage produced by ionizing radiation. Researchers experiments indicated that radiation damage in exponentially growing Chinese hamster cells could be fixed in a dose-dependent manner by postirradiation treatment with both hypertonic and hypotonic NaCl solutions. At a 1,000-rad dose level, survival could be depressed by a factor of about 260. For various treatments at either 42 or 45 degrees C, exposure after heating to anisotonic solutions did not result in the fixation of heat damage. When cells were heated at 45 degrees C for 5 minutes and irradiated with 500 rad before or after heating or given 500 rad without heating and then exposed to 0.05 M NaCl solutions for 120 minutes, survival was reduced by factors of 875, 667, and 12, respectively. For heat treatments at lower temperatures, such as 41.5 or 42 degrees C, less damage fixation for the combined treatments was observed. The data indicated that heat and radiation damage were different and damage from the combined treatments was not the same for low- and high-treatment temperatures.

  11. Mathematic modelling of kinetics for the crystallization of tungstic acid from electrolytically treated sodium tungstate solution

    International Nuclear Information System (INIS)

    The nucleation and growth rate kinetics for the continuous crystallization of tungstic acid from solution was studied in a 0.8 1 evaporative mixed suspension, mixed product removal crystallizer. The crystallizer included a draft tube which improved the uniformity of the suspension. Experimental conditions which were varied during the experimental runs were drawdown time of the crystallizer, stirrer speed of the stirrer in solution, heat flux to the crystallizing solution and the suspension density of the crystallizing magma. X-ray diffraction patterns of the tungstic acid material produced confirmed that the material was crystalline and that it was in the tungsten monohydrate (WO3.H2O) form. The crystal size distribution of the crystallizer magma was obtained under steady state conditions and used to calculate the crystal nucleation and growth rates. The main nucleation mechanism in the crystallizing system was contact secondary nucleation and the crystal growth rates were found to be crystal size dependent. A size dependent growth rate model was proposed which was incorporated in the population balance equation. Good fits of the model to the data were obtained using this population balance equation. Analysis of the expressions derived for the nucleation and nuclei sized crystal growth rates indicated that the nucleation rate was a linear function of crystallizer magma suspension density and that there existed an inverse relationship between the nucleation rate and the crystal growth rate of the nuclei sized crystals

  12. Corrosion behavior of silicon nitride in sodium hydroxide solutions at 175 deg C

    International Nuclear Information System (INIS)

    This paper presents results of the corrosion of Si3 N4 in aqueous solutions of NaOH (37,5%) at 15 deg C.The corrosive attack was evaluated from the weight loss of the samples.A constant rate was observed, signifying that the corrosion rate depends only on the velocity of the dissolution by the NaOH solution. The corrosion rates of Si3 N4 doped with Y2 O3/ Si O2 and a rare earth concentrate/Si O2 yielded 1,19 x 10 -3 g cm-2 h-1 and 0,78 x 10-3 g cm -2 h-1, respectively. Analysis of the corroded samples by electronic microscopy revealed that the glassy intergranular phase is dissolved by the alkaline solution, leaving a skeleton of inter linked ? - Si3 N4 grains. The mechanical resistance of the corroded samples was determined and demonstrated mechanical degradation of the material. (author)

  13. The crevice corrosion behaviour of stainless steel in sodium chloride solution

    International Nuclear Information System (INIS)

    Highlights: ? There are three stages in crevice corrosion of 13Cr stainless steel in NaCl solution. ? The decrease of crevice thickness shortens the incubation period of crevice corrosion. ? The incubation period of crevice corrosion prolongs as the increase of the area ratio. ? Corrosion develops preferentially at crevice bottom and hydrogen reduction occurs inside the crevice. ? Crevice corrosion of 13Cr stainless steel in NaCl solution follows the passive dissolution mechanism. - Abstract: The crevice corrosion behaviour of 13Cr stainless steel in NaCl solution was investigated mainly by electrochemical noise measurements, considering the influences of the crevice opening dimension (a) and the area ratio of the electrode outside the crevice to the one inside the crevice (r). Results show that the increase of r value prolongs the incubation period of crevice corrosion, but crevice corrosion develops rapidly once the crevice corrosion occurs. The crevice corrosion develops preferentially at the crevice bottom and then spreads to the whole electrode surface. Proton could reduce on the uncorroded area and hydrogen bubbles form inside the crevice.

  14. Localized corrosion of nickel-based steam generator tubing alloys in sodium sulfate solutions containing thiosulfate

    International Nuclear Information System (INIS)

    Pitting of steam generator tubing alloys 600, 800 and 690 was studied using chloride-free solutions containing aggressive thiosulfate ions, simulating events that may occur during plant outages when reduced sulfur in sludge piles reacts with incoming oxygen. All three alloys showed pitting at 60oC and potentials that would be easily attained in practice. The most aggressive condition is a molar ratio (sulfate to thiosulfate) of 40, irrespective of the ionic strength of the solution, reflecting the mutual electromigration of the anions into the pit cavity. The strong-acid anion (sulfate) is required to sustain acidification in the pit, while the thiosulfate is reduced to activating adsorbed sulfur on the pit surface. Extremely diluted solutions, in the micromolar range, continue to cause pitting. The conditions for intergranular corrosion are less specific, reflecting the lower corrosion resistance of the grain-boundary material in that case. Studies of oxygen reduction on alloy surfaces pre-exposed to hot water prior to low-temperature exposure have been carried out, and show that whilst the kinetics are quite slow, with increased Cr alloying being beneficial, they are adequate to sustain pitting in practice. (author)

  15. Saturated sodium chloride solution under an external static electric field: A molecular dynamics study

    Science.gov (United States)

    Ren, Gan; Wang, Yan-Ting

    2015-12-01

    The behavior of saturated aqueous NaCl solutions under a constant external electric field (E) was studied by molecular dynamics (MD) simulation. Our dynamic MD simulations indicated that the irreversible nucleation process towards crystallization is accelerated by a moderate E but retarded or even prohibited under a stronger E, which can be understood by the competition between self-diffusion and drift motion. The former increases with E, thereby accelerating the nucleation process, whereas the latter pulls oppositely charged ions apart under a stronger E, thereby decelerating nucleation. Additionally, our steady-state MD simulations indicated that a first-order phase transition occurs in saturated solutions at a certain threshold Ec. The magnitude of Ec increases with concentration because larger clusters form more easily when the solution is more concentrated and require a stronger E to dissociate. Project supported by the National Basic Research Program of China (Grant No. 2013CB932804) and the National Natural Science Foundation of China (Grant Nos. 91227115, 11274319, and 11421063).

  16. Solvation of Dimethyl Succinate in a Sodium Hydroxide Aqueous Solution. A Computational Study

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiuquan; Chang, Tsun-Mei; Cao, Yang; Niwayama, Satomi; Hase, William L.; Dang, Liem X.

    2009-05-07

    Molecular dynamics simulations were carried out to study dimethyl-succinate/water/NaOH solutions. The potential of mean force method is used to determine the transport mechanism of a dimethyl-succinate (a diester) molecule across the aqueous/vapor interface. The computed number density profiles show a strong propensity for the diester molecules to congregate at the interface with the solubility of the diester increasing with increasing NaOH concentration. It is observed that the major contribution to the interfacial solvation free energy minimum is from van der Waals interactions. Thus, even at higher NaOH concentrations, the increasing electrostatic interaction between the diester and ions is not large enough to overcome the Lennard-Jones (LJ) interactions to favor the solvation of diester in bulk solutions. The calculated solvation free energies are found to be -2.6 ~ -3.5 kcal/mol in variant concentrations of NaOH aqueous solutions. These values are in qualitative agreement with the corresponding experimental measurements. The computed surface potential indicates that the contribution of diester molecules to the total surface potential is about 25%, with the major contribution from interfacial water molecules. This work was supported by the US Department of Energy (DOE) Office of Basic Energy Sciences, Chemical Sciences program. Pacific Northwest National Laboratory is operated by Battelle for DOE.

  17. Anodic behavior of nickel alloys in media containing bicarbonate ions

    International Nuclear Information System (INIS)

    Alloy 22 has been designed to resist corrosion in oxidizing and reducing conditions. Thanks to these properties it is considered a possible candidate for the fabrication of containers of high-level radioactive waste. Since the containers provide services in natural environments characterized by multi-ionic solutions, it is estimated they could suffer three types of deterioration: general corrosion, localized corrosion (specifically crevice corrosion) and stress corrosion cracking (SCC). It has been confirmed that the presence of bicarbonate and chloride ions is required in order to produce cracking. It has also been determined that the susceptibility to SCC could be related to the occurrence of an anodic peak in the polarization curves in these media potentials below trans-passivity. The aim of this work is to study the anodic behavior of Alloy 22 in different media containing bicarbonate and chloride ions in various concentrations and temperatures and compare the results with other alloys containing nickel, and relate them to the susceptibility to stress corrosion cracking in a future job. Polarization curves were made on alloy 22 (Ni-Cr-Mo), 600 (Ni- Cr-Fe), 800h (Ni-Fe- Cr) and 201 (Ni commercially pure) in the following environments: 1.148 mol/L NaHCO3, 1.148 mol/L NaHCO3 + 1 mol/L NaCl, 1.148 mol/L NaHCO3 + 0.1 mol/L NaCl. The tests were performed at the following temperatures: 90°C, 75°C, 60°C and 25°C. It was found that alloy 22 has a current peak in the anodic domain at potentials below trans-passivity between 200 and 300 m VECS, when the test temperature was 90°C. The potential, at which this peak occurred, increased with decreasing temperature. Also there was a variation of the peak with the composition of the solution. When bicarbonate ions were added to a solution containing chloride ions, the peak potential shifted to higher current densities, depending on the concentration of added chloride ions. It was found that diminishing the content of alloying elements, produced a decrease in the peak potential. No anodic peak was observed in the alloy with the lowest content of alloying elements. There was no dependence of current peak with the presence of alloying elements. (author)

  18. Effect of sodium phosphate salts on the thermodynamic properties of aqueous solutions of poly(ethylene oxide) 6000 at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Rahmat [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)], E-mail: rahsadeghi@yahoo.com; Hosseini, Rahim; Jamehbozorg, Bahman [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2008-09-15

    Precise density, sound velocity, water activity, and phase diagram measurements have been carried out on polyethylene oxide (PEO) in aqueous solutions of sodium di-hydrogen phosphate, di-sodium hydrogen phosphate, and tri-sodium phosphate over a range of temperatures at atmospheric pressure. The experimental density and sound velocity data are used to calculate the apparent specific volume and isentropic compressibility as a function of temperature and concentration. It was found that both of the apparent specific volume and isentropic compressibility of PEO in aqueous solutions increase by increasing temperature and charge on the anion of electrolytes. The results show that the slope of constant water activity lines increased with increasing the temperature and charge on the anion of electrolytes and the vapour pressure depression for an aqueous (PEO + sodium phosphate) system is more than the sum of those for the corresponding binary solutions. Furthermore, the effect of temperature and type of anion of salt on the salting-out effect of polyethylene oxide by sodium phosphate salts has been studied.

  19. Effect of sodium phosphate salts on the thermodynamic properties of aqueous solutions of poly(ethylene oxide) 6000 at different temperatures

    International Nuclear Information System (INIS)

    Precise density, sound velocity, water activity, and phase diagram measurements have been carried out on polyethylene oxide (PEO) in aqueous solutions of sodium di-hydrogen phosphate, di-sodium hydrogen phosphate, and tri-sodium phosphate over a range of temperatures at atmospheric pressure. The experimental density and sound velocity data are used to calculate the apparent specific volume and isentropic compressibility as a function of temperature and concentration. It was found that both of the apparent specific volume and isentropic compressibility of PEO in aqueous solutions increase by increasing temperature and charge on the anion of electrolytes. The results show that the slope of constant water activity lines increased with increasing the temperature and charge on the anion of electrolytes and the vapour pressure depression for an aqueous (PEO + sodium phosphate) system is more than the sum of those for the corresponding binary solutions. Furthermore, the effect of temperature and type of anion of salt on the salting-out effect of polyethylene oxide by sodium phosphate salts has been studied

  20. Inefficacy of osmotic backwash induced by sodium chloride salt solution in controlling SWRO membrane fouling

    Science.gov (United States)

    Farooque, A. Mohammed; Al-Jeshi, Subhi; Saeed, Mohamed O.; Alreweli, Ali

    2014-12-01

    A study was conducted to evaluate the efficacy of osmotic backwash induced by high salt (NaCl) concentration solution on feed side of seawater reverse osmosis (SWRO) membranes, online and offline, in controlling membrane fouling and therefore minimizing/eliminating the need for chemical cleaning. SWRO membranes were deliberately fouled by feeding seawater from an open intake located on the Arabian Gulf Coast without dosing chemicals. The fouled membranes were subjected to offline cleaning with the salt solution of up to 25 % concentration. Despite the partial removal of foulants from the membrane surface, SWRO membrane performance could not be restored, indicating the ineffectiveness of osmotic backwash in aiding offline salt cleaning. Similarly, online osmotic backwash was found to be not only ineffective in removing foulants from membrane surfaces but actually increased the fouling rate, as indicated by faster fouling rates compared to other cases. Although the driving force required for the osmotic backwash existed, the generated back flow proved to be insufficient to detach foulants from membrane surfaces. During the study period, the average SWRO membrane flux was maintained between 19 and 23 LMH, whereas the average generated back flow flux by high salt concentration solution was only 11 LMH, which was not adequate to remove foulants from membrane surfaces. Moreover, it seems that the membrane configuration as well as inherent microstructure of SWRO membrane places certain constraints on the osmotic backwash process and renders osmotic backwash ineffective in tackling SWRO membrane fouling. Hence, chemical cleaning is essential to restore SWRO membrane performance whenever fouling occurs, and the use of highly concentrated salt solution does not have any significant benefit. Membrane autopsy revealed only an insignificant accumulation of biofouling layer despite the absence of disinfection. However, it was shown that culturable biofilm bacteria species isolated from membranes tolerated exposure to high salt concentrations at pH range of 7-8. In addition, the overall findings of the study indicate that SWRO membranes can be operated in Gulf seawater at a recovery of 30 % without using any chemicals, such as coagulant, disinfectant and antiscalant, for an acceptable period of time without performing membrane cleaning. This is highly likely, if media filters are used in the pretreatment and SWRO membranes are operated at normal flux and recovery ratio.

  1. Phase formation in zirconium sulfate solutions in the presence of sodium fluorides

    International Nuclear Information System (INIS)

    The following crystalline phases: Na3ZrF7, Na5Zr2F13 fluorozirconates; Na2ZrF4SO4, Na2ZrF2(SO4)2x2.5H2O fluorosulfatozirconates; NaZrF3O oxofluorozirconate and varying composition amorphous phase-are extracted from Zr(SO4)2x4H2O solutions containing 2-18 mass.%ZrO2 at NaF introduction up to F/Zr=0.5-7.0 molar ratios. Compounds are identified using chemical, crystallooptical, X-ray phase, thermal analyses and IR spectrometry

  2. Mechanism of immersion deposition of Ni-P films on Si(100) in an aqueous alkaline solution containing sodium hypophosphite

    International Nuclear Information System (INIS)

    The immersion deposition of Ni-P films on Si(100) surface without prior activation by metallic catalytic was carried out in an aqueous alkaline solution containing sodium hypophosphite. The deposition mechanism was investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Two stages of deposition were observed when the Si substrate was immersed in the deposition solution at an appropriate pH value. In the first stage, crystalline Ni nanoparticles were formed through a galvanic displacement reaction, which accompanied the oxidation of Si substrate without involving the reducing agent, NaH2PO2. Experimental results indicate that the oxidation states of Si4+ and Si3+ exist in the oxide layer. The amount of suboxide, Si3+, increased with deposition time, and the oxide layer became activated. In the second stage, amorphous Ni-P was deposited on this activation oxide layer in a process involving the reducing agent. The microscopic structure of the deposition film, observed by TEM cross-sectional analysis, verifies the mechanism of deposition suggested in this study.

  3. Dispersion effect of sodium hexametaphosphate on the photocatalytic efficiency of a solution-combusted ZnO nanopowder

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung; Choi, Gil Rak; Kim, Ji Hye; Lee, Jae Chun [Myongji University, Yongin (Korea, Republic of); Kim, Sun Jae [Sejong University, Seoul (Korea, Republic of)

    2012-11-15

    ZnO nanopowder was synthesized by using a unique method combusting a mixed water solution that contained an oxidant and a fuel. Zn(OH){sub 2} powder was used as an oxidant (source material). Three kinds of fuels, glycine, carbohydrazide and urea, were respectively used to synthesize the ZnO nanopowder. Sodium hexametaphosphate was used as a dispersant to avoid aggregation of the ZnO nanoparticles in the solution. The zeta potential and the ion mobility of the dispersed ZnO nanoparticles were measured to evaluate the dispersion properties. The ZnO nanopowder synthesized with glycine showed highest zeta potential and ion mobility. A photocatalytic reaction was performed to evaluate the photocatalytic efficiency. The dispersion of the ZnO nanoparticles in waste water enhanced the Cu{sup ++} ion removal from the waste water. The Cu{sup ++} ions were completely removed in 15 h with dispersion. Without dispersion, however, they were not completely removed, not even in 35 h. This means that the dispersant changed even the extreme performance limit of the photocatalyst.

  4. Standard practice for exposure of metals and alloys by alternate immersion in neutral 3.5% Sodium Chloride solution

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This practice covers procedures for making alternate immersion stress corrosion tests in 3.5 % sodium chloride (NaCl) (). It is primarily for tests of aluminum alloys (Test Method G 47) and ferrous alloys, but may be used for other metals exhibiting susceptibility to chloride ions. It sets forth the environmental conditions of the test and the means for controlling them. Note 1 Alternate immersion stress corrosion exposures are sometimes made in substitute ocean water (without heavy metals) prepared in accordance with Specification D 1141. The general requirements of this present practice are also applicable to such exposures except that the reagents used, the solution concentration, and the solution pH should be as specified in Specification D 1141. 1.2 This practice can be used for both stressed and unstressed corrosion specimens. Historically, it has been used for stress-corrosion cracking testing, but is often used for other forms of corrosion, such as uniform, pitting, intergranular, and galvanic. ...

  5. Dispersion effect of sodium hexametaphosphate on the photocatalytic efficiency of a solution-combusted ZnO nanopowder

    International Nuclear Information System (INIS)

    ZnO nanopowder was synthesized by using a unique method combusting a mixed water solution that contained an oxidant and a fuel. Zn(OH)2 powder was used as an oxidant (source material). Three kinds of fuels, glycine, carbohydrazide and urea, were respectively used to synthesize the ZnO nanopowder. Sodium hexametaphosphate was used as a dispersant to avoid aggregation of the ZnO nanoparticles in the solution. The zeta potential and the ion mobility of the dispersed ZnO nanoparticles were measured to evaluate the dispersion properties. The ZnO nanopowder synthesized with glycine showed highest zeta potential and ion mobility. A photocatalytic reaction was performed to evaluate the photocatalytic efficiency. The dispersion of the ZnO nanoparticles in waste water enhanced the Cu++ ion removal from the waste water. The Cu++ ions were completely removed in 15 h with dispersion. Without dispersion, however, they were not completely removed, not even in 35 h. This means that the dispersant changed even the extreme performance limit of the photocatalyst.

  6. Differential proteomics to explore the inhibitory effects of acidic, slightly acidic electrolysed water and sodium hypochlorite solution on Vibrio parahaemolyticus.

    Science.gov (United States)

    Chen, Tai-Yuan; Kuo, Shu-Hao; Chen, Shui-Tein; Hwang, Deng-Fwu

    2016-03-01

    Slightly acidic electrolysed water (SlAEW) and acidic electrolysed water (AEW) have been demonstrated to effectively inactivate food-borne pathogens. However, the underlying mechanism of inactivation remains unknown. Therefore, in this study, a differential proteomic platform was used to investigate the bactericidal mechanism of SlAEW, AEW, and sodium hypochlorite (NaOCl) solutions against Vibrio parahaemolyticus. The upregulated proteins after SlAEW, AEW, and NaOCl treatments were identified as outer membrane proteins K and U. The downregulated proteins after the SlAEW, AEW, and NaOCl treatments were identified as adenylate kinase, phosphoglycerate kinase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and enolase, all of which are responsible for energy metabolism. Protein synthesis-associated proteins were downregulated and identified as elongation factor Tu and GAPDH. The inhibitory effects of SlAEW and AEW solutions against V. parahaemolyticus may be attributed to the changes in cell membrane permeability, protein synthesis activity, and adenosine triphosphate (ATP) biosynthesis pathways such as glycolysis and ATP replenishment. PMID:26471589

  7. Modelling the process of Al(OH3 crystallization from industrial sodium aluminate solutions using artificial neural networks

    Directory of Open Access Journals (Sweden)

    ŽIVAN ŽIVKOVI?

    2011-08-01

    Full Text Available This paper presents an attempt to define the non-linear correlation dependence between the degree of decomposition of the aluminate solution, the average diameter of the crystallized gibbsite, the total Na2O content in the ob­tained alumina and the specific utilization level of the process on the one hand and important input parameters of the process on the other. As input pa­rameters having an influence on the process, the concentration of Na2O (caus­tic, the caustic ratio and the crystallization ratio, the starting and final tem­pe­rature of the process, the average diameter of the crystallization seed and the duration of the decomposition process were considered. As the result of mea­surements of these process parameters and the acquisition of the resulting out­put parameters of the process, a database with 500 data lines was obtained. To define the correlation dependence, with the aim of predicting the process para­meters of the decomposition process of the sodium aluminate solution, the arti­ficial neural network (ANN methodology was applied.

  8. Nanostructured sodium lithium niobate and lithium niobium tantalate solid solutions obtained by controlled crystallization of glass

    International Nuclear Information System (INIS)

    Transparent, nanostructured glass ceramics based on ferroelectric solid solutions of the type Na1-xLi xNbO3 (in very narrow composition regions for x = 0.12 and 0.93) and LiNb1-yTa yO3 (y = 0.5 unlimited solid solubility), can be obtained by controlled crystallization of glass. The parent glass samples were prepared by conventional melt-quenching technique. Heat-treatment of the parent glasses was performed at the various temperatures, for the same time. The glass structure evolution during the controlled crystallization was examined by FT-IR spectroscopy analysis. Crystalline phases were identified by X-ray diffraction analysis and SEM was used for microstructure characterization. Densities of the crystallized glasses were measured by Archimedean principle. The capacitance and dielectric loss tangent were measured at a frequency of 1 kHz, at the room temperature. It was found that in the all investigated systems crystallize solid solutions Na1-xLi xNbO3 and LiNb1-yTa yO3 in the glassy matrix, have crystal size on nanoscale (less than 100 nm), which is one of requirements to get a transparent glass ceramic that could be a good ferroelectric material regarding to the measured properties

  9. Polarographic study of electroreduction kinetics of molybdenum(6) complexes in acid solutions of sodium sulfate

    International Nuclear Information System (INIS)

    Electroreduction kinetics of molybdenum(6) complexes under 0.6-4.1 pH at presence of 1 MNa2SO4 is studied by means of polarographic technique. Three polarographic wave are obtained at CMo(6) = 2x10-5 - 2x10-4 mole/l concentration. First one of them is corresponded by adsorption limiting current on the basis of which the value of surface per one molybdenum (5) complex adsorbed on mercury is calculated. The second one is corresponded by diffusion limiting current on the basis of which diffusion factor of single-nuclear complex of molybdenum(5) participating in single-electron reaction is calculated. The third wave is a kinetic one. Effect of molybdenum(5) concentration and pH solution on the character of the first and the second waves is discussed

  10. Pulse radiolysis of aqueous solutions of sodium azide: reactions of azide radical with tryptophan and tyrosine

    International Nuclear Information System (INIS)

    Azide radicals (N3) are formed on reactions of azide anions (N-sub(3aq)) and hydroxyl radicals in aqueous solutions. Mechanisms of formation of N3 and its reactions with the amino acids tryptophan (trpH) and tyrosine (tyrH), which gave the radicals trp and tyr, respectively, and with some inorganic transients, have been studied by use of the pulse radiolysis technique. Variation of pH has no significant effect on the formation or decay of the azide radical. Its decay rate increases with the concentration of N-sub(3aq); this is consistent with the formation of the diazide radical anion. Electron transfer reactions of N-sub(3aq) with the isopropyl radical and the dithiocyanate radical anion have been studied. The results are discussed. (author)

  11. Investigation of the corrosion of pure magnesium in aerated sodium sulfate solutions

    International Nuclear Information System (INIS)

    The electrochemical behavior of magnesium in aerated Na2SO4 solutions was investigated by current-voltage curves and electrochemical impedance measurement. Dissolved magnesium was quantitatively determined by means of atomic absorption spectrophotometry. The electrochemical results show the occurrence of two concentration ranges. At low concentrations (0.001M-0.01M), low current densities and high resistance values were observed whereas at high concentrations (0.05M-0.5M) high currents and low resistances were measured. In parallel, atomic absorption spectrophotometry revealed that the number of electrons transferred depends on the Na2SO4 concentration. The assumption of the formation of labile or stable magnesium hydroxide allows us to explain the results obtained. (author)

  12. Corrosion Behavior of Stainless Steels in Neutral and Acidified Sodium Chloride Solutions by Electrochemical Impedance Spectroscopy

    Science.gov (United States)

    Calle, L. M.; Kolady, M. R.; Vinje, R. D.

    2004-01-01

    The objective of this work was to evaluate the corrosion performance of three alloys by Electrochemical Impedance Spectroscopy (EIS) and to compare the results with those obtained during a two-year atmospheric exposure study.' Three alloys: AL6XN (UNS N08367), 254SM0 (UNS S32154), and 304L (UNS S30403) were included in the study. 304L was included as a control. The alloys were tested in three electrolyte solutions which consisted of neutral 3.55% NaC1, 3.55% NaC1 in 0.lN HC1, and 3.55% NaC1 in 1.ON HC1. These conditions were expected to be less severe, similar, and more severe respectively than the conditions at NASA's Kennedy Space Center launch pads.

  13. Small volume resuscitation with hypertonic sodium chloride solution in cattle undergoing surgical correction of abomasal volvulus

    DEFF Research Database (Denmark)

    Sickinger, M.; Doll, K.

    2014-01-01

    A randomized clinical trial was conducted to compare the efficacy of rapid intravenous (IV) infusion of a 7.2% hypertonic saline solution with that of continuous application of an isotonic solution in stabilizing the circulation of cows with abomasal volvulus. Cattle treated with hypertonic saline had a significantly greater reduction in volume deficit within the first 10min of therapy than cows treated with isotonic saline (from 5.9±4.8 to 2.1±4.4L/100kg vs. 7.0±4.5 to 4.9±3.8L/100kg, respectively). The central venous pressure (CVP) of the cows given the hypertonic saline rose within the first 10 min of therapy from 7.3±3.5 to 10.8±3.4cm H2O, while the CVP of the cattle treated with isotonic saline did not increase significantly during this time.Sixty minutes after the start of the infusion, the CVP of the isotonic group was still significantly lower than that of the hypertonic group (9.5±2.1 vs. 10.3±3.3cm H2O, respectively). Within the first 60min, the base excess decreased from 5.5±6.9 to 4.7±6.2mmol/L inthe hypertonic group whereas it increased from 5.6±5.7 to 6.8±5.4mmol/L in the isotonic group. These results suggest that for cows with abomasal volvulus, IV therapy with hypertonic saline may improve the haemodynamic and circulatory situation considerably faster and more effectively than continuous infusion with isotonic saline.

  14. 1H NMR and IR study of temperature-induced phase transition of negatively charged poly(N-isopropylmethacrylamide-co-sodium methacrylate) copolymers in aqueous solutions.

    Czech Academy of Sciences Publication Activity Database

    Starovoytova, Larisa; Sp?vá?ek, Ji?í; Trchová, Miroslava

    2007-01-01

    Ro?. 43, ?. 12 (2007), s. 5001-5009. ISSN 0014-3057 R&D Projects: GA ?R GP203/07/P378 Institutional research plan: CEZ:AV0Z40500505 Keywords : thermosensitive polyelectrolytes * poly(N-isopropylmethacrylamide-co-sodium methacrylate) copolymers * aqueous solutions Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.248, year: 2007

  15. Solubility of NaNd(CO3)2.6H2O(c) in concentrated Na2CO3 and NaHCO3 solutions

    International Nuclear Information System (INIS)

    NaNd(CO3)2 x 6 H2O(c) was identified to be the final equilibrium solid phase in suspensions containing concentrated sodium carbonate (0.1 to 2.0 M) and sodium bicarbonate (0.1 to 1.0 M), with either NaNd(CO3)2 x 6 H2O(c) or Nd2(CO3)3 x xH2O(s) as initial solids. A thermodynamic model, based on Pitzer's specific into-interaction approach, was developed to interpret the solubility of NaNd(CO3)2 x 6 H2O(c) as functions of sodium carbonate and sodium bicarbonate concentrations. In this model, the solubility data of NaNd(CO3)2 x 6 H2O(c) were explained by assuming the formation of NdCO3+, Nd(CO3)2- and Nd(CO3)33- species and invoking the specific ion interactions between Na+ and Nd(CO3)33-. Ion interaction parameters for Na+-Nd(CO3)33- were developed to fit the solubility data. Based on the model calculations, Nd(CO3)33- was the predominant aqueous neodymium species in 0.1 to 2 M sodium carbonate and 0.1 to 1 M sodium bicarbonate solutions. The logarithm of the NaNd(CO3)2 x 6 H2O solubility product (NaNd(CO3)2 x 6 H2O(c)=Na++Nd3++2 CO32-+6 H2O) was calculated to be -21.39. This model also provided satisfactory interpretation of the solubility data of the analogous Am(III) system in less concentrated carbonate and bicarbonate solutions. (orig.)

  16. -Saturated Solutions

    Science.gov (United States)

    Eliyan, Faysal Fayez; Alfantazi, Akram

    2014-11-01

    This paper presents an electrochemical study on the corrosion behavior of API-X100 steel, heat-treated to have microstructures similar to those of the heat-affected zones (HAZs) of pipeline welding, in bicarbonate-CO2 saturated solutions. The corrosion reactions, onto the surface and through the passive films, are simulated by cyclic voltammetry. The interrelation between bicarbonate concentration and CO2 hydration is analyzed during the filming process at the open-circuit potentials. In dilute bicarbonate solutions, H2CO3 drives more dominantly the cathodic reduction and the passive films form slowly. In the concentrated solutions, bicarbonate catalyzes both the anodic and cathodic reactions, only initially, after which it drives a fast-forming thick passivation that inhibits the underlying dissolution and impedes the cathodic reduction. The significance of the substrate is as critical as that of passivation in controlling the course of the corrosion reactions in the dilute solutions. For fast-cooled (heat treatment) HAZs, its metallurgical significance becomes more comparable to that of slower-cooled HAZs as the bicarbonate concentration is higher.

  17. Multielement NMR studies of the liquid-liquid phase separation and the metal-to-nonmetal transition in fluid lithium- and sodium-ammonia solutions.

    OpenAIRE

    Lodge, MT; Cullen, P; Rees, NH; Spencer, N.; Maeda, K.; Harmer, JR; Jones, MO; Edwards, PP

    2013-01-01

    (1)H, (7)Li, (14)N, and (23)Na high resolution nuclear magnetic resonance (NMR) measurements are reported for fluid solutions of lithium and sodium in anhydrous liquid ammonia across the metal-to-nonmetal transition (MNM transition), paying particular attention to the phenomenon of liquid-liquid phase separation which occurs in the composition/temperature region close to the MNM transition. Our results are discussed in terms of the electronic structure of fluid metal-ammonia solutions at low ...

  18. Effect of Azotobacter vinelandii and Compatible Solutes on Germination Wheat Seeds and Root Concentrations of Sodium and Potassium under Salt Stress

    OpenAIRE

    H. Silini-Cherif; A. Silini; Ghoul, M

    2012-01-01

    The effect of Plant Growth-promoting Rhizobacteria (PGPR) and exogenous application of compatible solutes on seed germination and root concentrations of sodium and potassium of two wheat varieties (Triticum durum L.) were evaluated under saline stress. In this experiment, Azotobacter vinelandii strain DSM85, glycine betaine and proline were used. Inoculated seeds for each variety were placed on Whatman paper in 9 cm Petri dishes containing 15 mL of distilled water or NaCl solutions at various...

  19. SiO2-supported ferromagnetic catalysts for hydrogen generation from alkaline NaBH4 (sodium borohydride) solution

    International Nuclear Information System (INIS)

    Ferromagnetic elements Fe, Ni and Co were immobilized on the porous SiO2 to catalyze the hydrogen generation from aqueous alkaline NaBH4 (sodium borohydride). The porous SiO2 was prepared by silica-surfactant self-assembly and the ferromagnetic catalyst was prepared by chemical reduction. The ferromagnetic catalysts were characterized using TG/DTA (Thermogravimetry/differential thermal analysis), BET, XRD (X-ray powder diffraction), ESEM/EDS (environmental scanning electron microscope/energy dispersive spectroscopy), XPS (x-ray photoelectron spectroscopy) and VSM (vibration sample magnetometer) measurements. The surface area of porous SiO2 was affected by the molecular weight of surfactant. The relative catalytic activities in the generation of hydrogen from alkaline NaBH4 solution follow the order Co/SiO2 > Ni/SiO2 > Fe/SiO2. The rates of hydrogen generation using Co/SiO2, Ni/SiO2 and Fe/SiO2 catalysts in 20 ml of 5 wt.% NaBH4 solution at 313 K were 8701, 307 and 130 ml min?1 g?1-metal, respectively. It is found that the degree of metal-oxidation and crystal structure affected the catalytic activity. The hydrogen generation of NaBH4 in alkaline solution increased with increasing cobalt loading, of which the activation energy was 59 ± 2 kJ mol?1. - Highlights: ? Ferromagnetism/SiO2 was synthesized for hydrogen generation. ? The catalytic activities follow the order Co/SiO2 > Ni/SiO2 > Fe/SiO2. ? The ferromagnetic catalysts are stable and cheaper than ruthenium-coated catalysts

  20. Real surface area of the aluminium electrode in sodium chloride solution

    Directory of Open Access Journals (Sweden)

    Z. RAKOCEVIC

    1999-11-01

    Full Text Available By combining the techniques of electrochemical slow potentiodynamic, AC impedance and atomic force microscopy (AFM, it was shown that the differences in the anodic dissolution rates of Al in 0.5 NaCl solutions as measured experimentally in the potential region between the corrosion and pitting potential, are mainly due to differences in surface roughness of the electrodes used. It was shown that mechanical grinding and polishing of the electrode surface with emery paper (400 grit and alumina polishing powder (f 0.25 mm can produce surfaces differing by a factor of 6 in the roughness factor Ra. By using AFM estimates of the roughness factors a true electrode capacitance of 4.63 µC cm-2 and thickness dox ~ 2.0 nm for the barrier layer of the surface film was estamited. The outer part of the film is porous, partly as amorphous Al(OH3, or crystalline bayerite (Al2O3.3H2O.

  1. Selective removal of cesium from sodium nitrate solutions by potassium nickel hexacyanoferrate-loaded chabazites

    International Nuclear Information System (INIS)

    Potassium nickel hexacyanoferrate(II)s (KNiFC) were incorporated in the porous matrix of chabazite by successive impregnation with Ni(NO3)2 and K4Fe(CN)6. The loading percentage of KNiFC crystals on chabazite increased with repeated times of impregnation. The ion-exchange equilibrium of Cs+ in KNiFC-loaded chabazite (CFC) was attained within 2 days. Relatively large distribution coefficients of Cs+, Kd,Cs, above 104 cm3/g were obtained, irrespective of coexisting NaNO3 concentration. There is a large difference between the Kd value of 137Cs and those of other nuclides; the separation factor of Cs/Sr (?Cs/Sr = Kd,Cs/Kd,Sr) was estimated to be above 104. The breakthrough curve for Cs+ through the column packed with CFC exhibited a symmetrical S-shaped profile, and this exchanger proved to be effective for the selective removal of radiocesium from waste solutions containing highly concentrated NaNO3

  2. Pulse radiolysis study of reaction intermediates in aqueous solutions of sodium tetraphenylborate

    International Nuclear Information System (INIS)

    Solidification of waste radiocesium as an insoluble tetraphenylborate (TPB) salt is being carried out at the DOE Savannah River Plant. However, radiolysis of TPB solution or precipitate forms several organic products with substantial yield, including benzene, phenol, biphenyl and nitrobenzene. The TPB- anion is a reducing species and should be more readily attacked by OH than by e- or Hsm-bullet. Using the pulse radiolysis technique, the authors are able to confirm the lack of reactivity of TPB with e-, by directly monitoring the transient signal due to e-. Two schemes for reaction of OHsm-bullet with TPB- are under investigation; a rapid electron transfer from B(C6H5)4- to OHsm-bullet and addition of OHsm-bullet to B(C6H5)4-. They find that OH addition is dominant under conditions of N2O saturation as evidenced by the appearance of sequential transient species with ?max near 330 nm formed immediately after the pulse. Spectra obtained are different from the transient species B(C6H5)sm-bullet, formed via electron transfer when both N2O and excess NaN3 are present

  3. Clarification of sodium silicate solutions derived from diatomites, to improve their industrial expectations

    International Nuclear Information System (INIS)

    solutions of soluble silicates synthesized have been clarified in Costa Rica from diatomite in almost 50% of their initial coloration. Clarification and removal of iron oxides have been achieved in a higher order of 50% m/m expressed as Fe2 O3. Activated carbon treatment has clarified the scope of [31-57]%, but not significantly decreases the iron content. The application of NaClO to 3% m/m clarifies the scope of [28-51]%, and reduced iron by 48% m/m. The land alone has been shown that is not very effective filter to clarify, [0-14]%, but is effective for the stripping of iron by 68% m/m. Other procedures are effective in clarifying the scope of [42-51]% and reduced the amount of iron in the field of [48-66]%. The synthesis of soluble glasses is possible to clarify for conditioning with commercial purposes diverse, treatment methodologies and analytical control, simple and economical. (author)

  4. Storage of Anthropogenic Carbon Dioxide as Ocean Bicarbonate

    Science.gov (United States)

    Rau, G. H.; Caldeira, K.

    2006-12-01

    Fossil fuels will likely remain the world's primary energy source for the foreseeable future. Practical and safe means of lowering the associated CO2 emissions are therefore needed to avoid potentially catastrophic climate and environmental impacts. The ocean should not be ignored in assessing both CO2 effects and mitigation options. Accelerated weathering of limestone (AWL) is a candidate technology that could significantly contribute to lowering CO2 emissions as well as to chemically mitigating the effects of ocean acidification. Our research has shown that contacting flue gas (from fossil fuel combustion) with seawater and limestone presents a simple, low-tech way of spontaneously reacting CO2 out of waste gas streams to form a bicarbonate-rich solution via the reaction: CO2 + CaCO3 + H2O Ca2+ + 2HCO3-. (An analogous seawater process is already commercially used in some locations to remove flue gas SOx.) Our modeling studies show that disposing of the resulting calcium bicarbonate-rich solution in the ocean would provide effective, long-term carbon sequestration. It would also add carbonate alkalinity, thus countering the effects of CO2-caused ocean acidification on corals, shellfish, and other calcifying marine organisms. AWL reactors could be optimized for carbon storage or for mitigation of ocean acidification. Experiments have shown that seawater can tolerate >18x saturation before calcium carbonate precipitation is chemically initiated. It is therefore unlikely that once AWL effluent is in the ocean that degassing of some residual CO2 would lead to a reversal of the above reaction and subsequent carbonate precipitation. It is proposed that the cost, safety, impacts, and effectiveness of AWL be further evaluated as a means of mitigating CO2 from point sources, and of reducing the loss of marine calcification.

  5. Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy

    KAUST Repository

    Geise, Geoffrey M.

    2013-09-17

    Many salinity gradient energy technologies such as reverse electrodialysis (RED) rely on highly selective anion transport through polymeric anion exchange membranes. While there is considerable interest in using thermolytic solutions such as ammonium bicarbonate (AmB) in RED processes for closed-loop conversion of heat energy to electricity, little is known about membrane performance in this electrolyte. The resistances of two commercially available cation exchange membranes in AmB were lower than their resistances in NaCl. However, the resistances of commercially available anion exchange membranes (AEMs) were much larger in AmB than in NaCl, which would adversely affect energy recovery. The properties of a series of quaternary ammonium-functionalized poly(phenylene oxide) and Radel-based AEMs were therefore examined to understand the reasons for increased resistance in AmB to overcome this performance penalty due to the lower mobility of bicarbonate, 4.59 × 10-4 cm2/(V s), compared to chloride, 7.90 × 10-4 cm2/(V s) (the dilute aqueous solution mobility ratio of HCO3 - to Cl- is 0.58). Most membrane resistances were generally consistent with the dilute solution mobilities of the anions. For a few key samples, however, increased water uptake in AmB solution reduced the ionic resistance of the polymer compared to its resistance in NaCl solution. This increased water uptake was attributed to the greater hydration of the bicarbonate ion compared to the chloride ion. The increased resistance due to the use of bicarbonate as opposed to chloride ions in AEMs can therefore be mitigated by designing polymers that swell more in AmB compared to NaCl solutions, enabling more efficient energy recovery using AmB thermolytic solutions in RED. © 2013 American Chemical Society.

  6. Indomethacin decreases gastroduodenal mucosal bicarbonate secretion in humans

    DEFF Research Database (Denmark)

    Mertz-Nielsen, A; Hillingsø, Jens; Bukhave, K; Rask-Madsen, J

    1995-01-01

    BACKGROUND: Cyclooxygenase inhibitors reduce mucosal bicarbonate secretion in the duodenum, but the evidence for their effect on bicarbonate secretion in the stomach remains controversial. We have, therefore, studied how indomethacin influences gastroduodenal bicarbonate secretion and luminal...... healthy volunteers. Bicarbonate and PGE2 were measured in the gastroduodenal effluents by back-titration and radioimmunoassay, respectively. RESULTS: Vagal stimulation and duodenal luminal acidification (0.1 M HCl; 20 ml; 5 min) increased gastroduodenal bicarbonate secretion (p < 0.05). Indomethacin...... markedly inhibited both basal and stimulated gastric and duodenal mucosal bicarbonate secretion, and this reduction was similar to the degree of cyclooxygenase inhibition estimated by the luminal release of PGE2 (p < 0.05). CONCLUSION: These results unequivocally demonstrate that endogenous PG modulates...

  7. Voltammetry of lithium, sodium and potassium ions at the interface between two immiscible electrolyte solutions, using derivatives of benzo-15-crown-5

    International Nuclear Information System (INIS)

    Transfer of lithium, sodium and potassium ions through water/nitrobenzene interface using derivatives of benzo-15-crown-5 has been studied by the method of voltammetry on the interface of two immiscible electrolyte solutions. It has been ascertained that Li+ and Na+ ions form complexes of the composition ML+ with the ionophores, while K+ ions - ML2+ complexes. The values of standard transfer potentials, standard transfer energies of the complexes and their stability constants in nitrobenzene have been calculated. A method of joint determination of sodium and potassium ions has been suggested. 16 refs.; 4 figs.; 3 tabs

  8. Enhanced removal of bisphenol-AF onto chitosan-modified zeolite by sodium cholate in aqueous solutions.

    Science.gov (United States)

    Peng, Sha; Hao, Kunyan; Han, Feng; Tang, Zheng; Niu, Beibei; Zhang, Xu; Wang, Zhen; Hong, Song

    2015-10-01

    The removal of bisphenol-AF (BPAF) from aqueous solutions onto chitosan-modified zeolite (Ch-Z) in the absence and presence of sodium cholate (NaC) was investigated. It was found that NaC significantly increased the adsorption capacity of Ch-Z for BPAF. At an initial concentration of 100 ?mol/L, the removal of BPAF by adsorption onto Ch-Z with NaC was more than ninefold higher than without NaC, and the maximum removal was achieved at a Ch-Z dosage of 1g/L with a NaC concentration of 1.68 mmol/L. Besides, batch studies were performed to evaluate the effects of various experimental parameters on the removal of BPAF. Kinetic studies and adsorption isotherms indicated that the adsorption process of BPAF onto Ch-Z with NaC could be expressed by a pseudo second-order model and the Freundlich isotherm model, respectively. For the enhanced removal, an interaction mechanism was proposed involving the co-effect of BPAF and NaC adsorbed onto Ch-Z. PMID:26076637

  9. Study of corrosion processes on Al-AA 6061 crevices immersed in high purity water and sodium citrate solution

    International Nuclear Information System (INIS)

    An experimental approach has been developed to study the corrosion behavior of artificial crevices manufactured with high purity aluminum and AA 6061 alloy, immersed in dematerialised water and sodium citrate solution (96,5 μS/cm). Alkaline attack was found on the surrounding of iron rich particles in the external zone of the crevice, as a result of localized oxygen reduction reaction on these sites. This attack was not observed in the zone inside the crevice. Study of the phase Mg2Si by EDS allowed establishing that there is not preferential dissolution inside the crevice. The formation of a stable and non-soluble complex between Al and citrate anion inhibited the production of Al(OH)3 precipitate, which was observed on the surface of specimens immersed in pure water. Investigations of the aluminum oxide evolution on AA 6061 surfaces in water showed that it was composed by two layers: an internal one made of Bohemite and an external one in direct contact with the water, with a Bayerite structure. The surface analysis was accomplished using XR, OM and SEM techniques. (author)

  10. Vapor pressure, speciation, and chemical activities in highly concentrated sodium borate solutions at 277 and 317 degrees C

    International Nuclear Information System (INIS)

    The system H2O - B2O3 - Na2O has been studied experimentally at 277 and 317 degrees C. The activities of water and boric acid have been determined at mole ratios Na/B from 0 to 1.5, and total dissolved solids 3 to 8 weight percent. The activity of boric acid has been fitted to within experimental error using a speciation model with eight complex species. This model is consistent with the model previously published by Mesmer et al. The electrolyte properties of the liquid are modeled using the Pitzer-Simonson model of very concentrated electrolyte solutions. The calculated values of water activity agree with experiment, and the activity of NaOH and pOH have also been calculated. The potassium borate system also was briefly studied at 317 degrees C, and is adequately described by a model with five complex species. The potassium borate liquid is more alkaline at K/B = 1 than a sodium borate liquid at the same mole ratio, but pOH in the two systems is the same at lower mole ratios

  11. Silver nanoparticles synthesis in aqueous solutions using sulfite as reducing agent and sodium dodecyl sulfate as stabilizer

    International Nuclear Information System (INIS)

    The synthesis of silver nanoparticles has been carried out in aqueous solutions in a stirred semibatch reactor through the reduction of silver ions (Ag+) by sulfite ions (SO32?), which were added at a tightly controlled rate up to a final sulfite/silver molar ratio of 0.45. Sodium dodecyl sulfate (SDS) was used as the stabilizer at concentrations below its critical micelle concentration. The effects of temperature, sulfite addition rate, and SDS concentration have been assessed. Ag+ turned to Ag0 in 5 min or less only when the synthesis was performed at 97 °C and not below. The sulfite addition rates studied were 0.5, 7.5, 15, and 90 ?mol/min. The size, shape, polydispersity, and stability of the nanoparticles were determined by the sulfite addition rate and SDS concentration. At low SDS concentration (4 mM), stable, spherical shape, small size nanoparticles were formed only at the two intermediate sulfite addition rates. At the highest sulfite addition rate, 9 nm mean size spherical nanoparticles having a low ±5 nm polydispersity were produced at a high SDS concentration of 10 mM. With the low SDS concentration, larger truncated and spherical shape nanoparticles were obtained. UV–Vis spectrophotometry and transmission electron microscopy were used to characterize the nanoparticles.

  12. Correcting Acidosis during Hemodialysis: Current Limitations and a Potential Solution.

    Science.gov (United States)

    Tovbin, David; Sherman, Richard A

    2016-01-01

    The deleterious catabolic and pro-inflammatory effects of acidosis in hemodialysis (HD) patients and the importance of its correction for limiting mineral bone disease (MBD) are well known. Although oral base therapy could be a solution for correcting acidosis in HD patients, it increases their already enormous medication load and sodium intake; this approach is not used commonly. Therefore, we need to rely more on correcting acidosis during the HD procedure, which is difficult to achieve, in part, because HD is an intermittent therapy. The currently used fixed dialysate bicarbonate concentrations are associated with pre-HD acidosis and intra-dialytic alkalosis. We suggest that a decreasing dialysate bicarbonate concentration from an initially high concentration be considered as a means of correcting acidosis with limited intra-dialytic alkalosis. Some evidence, as well as theoretical considerations, supports such an approach. PMID:26593391

  13. Activation, inactivation and recovery in the sodium channels of the squid giant axon dialysed with different solutions.

    Science.gov (United States)

    Keynes, R D; Greeff, N G; Forster, I C

    1992-09-29

    Comparisons were made between families of ion currents recorded in voltage-clamped squid axons dialysed with 20 mM NaF and 330 mM CsF or TMAF, and bathed in a solution in which four fifths of the Na was replaced by Tris. The permeability coefficient PNa,fast for the fast-inactivating current in the initial open state was calculated as a function of test potential from the size of the initial peak of INa. The permeability coefficient PNa,non for the non-inactivating open state was calculated from the steady-state INa that persisted until the end of the test pulse. Dialysis with TMA had no direct effect on the QV curve for gating charge. The reversal potential for INa,non was always lower than that for INa,fast, the mean difference being about -9 mV when dialysing with Cs, but only about -1 mV with TMA. Except close to threshold, PNa,fast was roughly halved by dialysis with TMA as compared with Cs, but PNa,non was substantially increased. The time constant tau h inactivation of the sodium system was slightly increased during dialysis with TMA in place of Cs, and there were small shifts in the steady-state inactivation curve, but the rate of recovery from inactivation was not measurably altered. The flattening off of the tau h curve at increasingly positive test potentials corresponded to a steady reduction of the apparent inactivation charge until a value of about 0.2e was reached for pulses to 100 mV. The instantaneous I-V relationship in the steady state was also investigated. The results have a useful bearing on the effects of dialysis with TMA, on the differences between the initial and steady open states of the sodium channel, and on the relative voltage-dependences of the transitions in each direction between the resting and inactivated states. PMID:1359591

  14. Two low-dose bowel-cleansing regimens: efficacy and safety of senna and sodium phosphorus solution for colonoscopy

    Directory of Open Access Journals (Sweden)

    Poyrazoglu OK

    2015-09-01

    Full Text Available Orhan Kursat Poyrazoglu, Mehmet Yalniz Department of Gastroenterology, School of Medicine, Firat University, Elazig, Turkey Background: The aim of the present study was to compare the efficacy, adequacy, side effects, and patient compliance of sodium phosphorus (NaP and senna solutions when preparing the colon before colonoscopy.Methods: A total of 137 consecutive patients who were considered for colonoscopy evaluation had randomly received one of two premeditated regimens: 90 mL of oral NaP (NaP group or 500 mL of 1,000 mg of sennosides A and B calcium +66.6 g of sorbitol (senna group. Patients’ compliance with the bowel-cleansing method was determined using a questionnaire prior to the colonoscopic examination. On the other hand, the adequacy of the bowel-cleansing method was evaluated by the colonoscopist who was blind to the bowel-cleansing regimen used prior to the examination of the colon from the rectum to the cecum.Results: Nausea and vomiting complaints were seen more frequently in the NaP group than in the senna group (47 vs 28 and 31 vs 10; P<0.05 and P<0.01, respectively. The response to the question of whether the patients would like to use the same regimen again or not was similar in both groups. The acceptable bowel-cleansing rate was also comparable across both groups. Nevertheless, the number of patients that experienced excellent bowel cleansing in terms of general appraisal of the colonoscopic evaluation was significantly greater in the NaP group than in the senna group (46 vs 25; P<0.001.Conclusion: Although bowel cleansing was better in the NaP group, both cleansing regimens were comparable regarding the admissibility of the preparations for the procedure. The senna regimen is, however, superior to the NaP regimen in terms of application compliance and its side effects, and it may be an effective alternative for cleansing the bowel prior to colonoscopic examination. Keywords: bowel preparation, colonoscopy, side effect, senna, sodium phosphorus

  15. Caffeine, but not bicarbonate, improves 6 min maximal performance in elite rowers

    DEFF Research Database (Denmark)

    Christensen, Peter Møller; Petersen, Mads H; Friis, Signe N; Bangsbo, Jens

    2014-01-01

    This study examined the ergogenic effects in a 6 min maximal performance test (PT) on 12 elite rowers: 6 open-weight (mean ± SD; 25 ± 1 years, and 92 ± 3 kg) and 6 light-weight (25 ± 3 years, and 73 ± 6 kg), following supplementation with caffeine (CAF), sodium bicarbonate (SB), and the combination of both, in a double-blind randomized placebo (PLA) controlled design. PT was executed on 4 occasions, on separate days within a week, and in a non-fasted state, with standardized training being perfo...

  16. Carbon dioxide capture using Sodium bicarbonate/Sodium carbonate supported on nanoporous Iron(III) oxide

    Science.gov (United States)

    Dutcher, Bryce

    Strong evidence exists suggesting that anthropogenic emissions of CO 2, primarily from the combustion of fossil fuels, have been contributing to global climate change, including warming of the atmosphere and acidification of the oceans. These, in turn, lead to other effects such as melting of ice and snow cover, rising sea levels, severe weather patterns, and extinction of life forms. With these detrimental shifts in ecosystems already being observed, it becomes imperative to mitigate anthropogenic CO2. CO2 capture is typically a costly operation, usually due to the energy required for regeneration of the capture medium. Na2CO3 is one potential capture medium with the potential to decrease this energy requirement. Extensively researched as a potential sorbent for CO2, Na2CO3 is well known for its theoretically low energy requirement, due largely to its relatively low heat of reaction compared to other capture technologies. Its primary pitfalls, however, are its extremely low reaction rate during sorption and slow regeneration of Na2CO 3. Before Na2CO3 can be used as a CO2 sorbent, then, it is critical to increase its reaction rate. In order to do so, this project studied nanoporous FeOOH as a potential supporting material for Na2CO3. Because regeneration of the sorbent is the most energy-intensive step when using Na2CO3 for CO 2 sorption, this project focused on the decomposition of NaHCO 3, which is equivalent to CO2 desorption. Using BET, FTIR, XRD, XPS, SEM, TEM, magnetic susceptibility tests, and Mossbauer spectroscopy, we show FeOOH to be thermally stable both with and without the presence of NaHCO3 at temperatures necessary for sorption and regeneration, up to about 200°C. More significantly, we observe that FeOOH not only increases the surface area of NaHCO3, but also has a catalytic effect on the decomposition of NaHCO3, reducing activation energy from 80 kJ/mol to 44 kJ/mol. This reduction in activation energy leads to a significant increase in the reaction rate by a factor of nearly 50, which could translate into a substantial decrease in the cost of using Na2 CO3 for CO2 capture.

  17. Comparison between the Quality Traits of Phosphate and Bicarbonate-Marinated Chicken Breast Fillets Cooked under Different Heat Treatments

    OpenAIRE

    Samer Mudalal; Massimiliano Petracci; Silvia Tappi; Pietro Rocculi; Claudio Cavani

    2014-01-01

    Because the use of phosphates has being recently diminished in meat industry due to the nutritional drawbacks of phosphates, some researchers started to evaluate sodium bicarbonate as phosphate replacer in meat products. The aim of this study was to evaluate the effect of different temperature combinations of dry air-cooking treatments (Air and Core temperatures: 160 - 76, 160 - 80, 200 - 76 and 200? - 80?, respectively) on chemical composition, texture properties, wate...

  18. Standard test method for evaluating stress-corrosion cracking of stainless alloys with different nickel content in boiling acidified sodium chloride solution

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method describes a procedure for conducting stress-corrosion cracking tests in an acidified boiling sodium chloride solution. This test method is performed in 25% (by mass ) sodium chloride acidified to pH 1.5 with phosphoric acid. This test method is concerned primarily with the test solution and glassware, although a specific style of U-bend test specimen is suggested. 1.2 This test method is designed to provide better correlation with chemical process industry experience for stainless steels than the more severe boiling magnesium chloride test of Practice G36. Some stainless steels which have provided satisfactory service in many environments readily crack in Practice G36, but have not cracked during interlaboratory testing using this sodium chloride test method. 1.3 This boiling sodium chloride test method was used in an interlaboratory test program to evaluate wrought stainless steels, including duplex (ferrite-austenite) stainless and an alloy with up to about 33% nickel. It may also b...

  19. Cromolyn Sodium Nasal Solution

    Science.gov (United States)

    ... pharmacist, or respiratory therapist to demonstrate the proper technique. Practice using the device while in his or her presence.If you are to use the nasal spray, first blow your nose, and clear it as ...

  20. Electrolyte and glucose contents of ripe and unripe coconut liquid as source of oral rehydration solution

    Directory of Open Access Journals (Sweden)

    A O Adegoke

    2012-04-01

    Full Text Available Summary: Electrolyte and glucose contents of 20 ripe and 20 unripe coconuts were analysed along with a commercially prepared oral rehydration solution using flame photometry for sodium, potassium and back titration method for bicarbonate estimation while glucose oxidase method was carried out for glucose estimation. The unripe coconut liquid had mean+ SEM of sodium (mmol/L 40.08 + 3.21, potassium (mmol/l 24.06 + 0.89, bicarbonate (mmol/l 1.48 + 0.20 and glucose (mmol/l 26.30 + 0.21 while the ripe coconut liquidhad sodium (mmol/l 24.60+ 1.36, Potassium (mmol/l 15.48 + 0.23, bicarbonate (mmol/l 0.80 + 0.18 and glucose concentration (mmol/l of 1.68 + 0.51 respectively. There was significant difference in the electrolyte content of the ripe and unripe coconut liquid (P< 0.05. The commercially prepared ORS had sodium (mmol/l 90.00 + 0.1, Potassium (mmol/l 20.00 + 0.1, bicarbonate (mmol/l 29.00 + 0.1 and glucose concentration (mmol/l of 111.00 + 0.1 respectively. The electrolyte and glucose contents of the ripe coconut was found not to meet minimum WHO standard of glucose concentration of 111mmol/l, sodium 90mmol/l, Potassium 20mmol/l and bicarbonate concentration of 30mmol/l for ORS. The Potassium concentration of the unripe coconut was higher than minimum WHO standard for ORS. However, the use of coconut liquid for rehydration cannot be recommended on the basis of its glucose and electrolyte composition.Industrial relevance: Coconut water is often used as an alternative solution for oral rehydration, particularly in regions where mothers' knowledge of oral rehydration is lacking. There has been no differentiation in the type of coconut water used for the purpose of replacing lost electrolytes; hence the electrolytes lost due to dehydration will not be replaced if the source of rehydration doesn’t contain the proper concentration of electrolytes. The study highlighted the deficiencies in the ripe and unripe coconut water as a rehydration source. Therefore a commercial source of rehydration is still the best source of oral rehydration since the coconut water is deficient in electrolytes to replace lost electrolytes.Keywords: Electrolyte; glucose; Coconut; Oral Rehydration Solution