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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

    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.

    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

    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.

    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

    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

    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.

    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

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

    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

  10. Oral rehydration therapy: efficacy of sodium citrate equals to sodium bicarbonate for correction of acidosis in diarrhoea.

    Islam, M. R.; Samadi, A R; Ahmed, S. M. [وسمية محمد أحمد; Bardhan, P K; Ali, A.

    1984-01-01

    Forty patients with moderate degrees of dehydration and acidosis because of acute watery diarrhoea were successfully treated randomly with either WHO recommended oral rehydration solution containing 2.5 g sodium bicarbonate or an oral solution containing 2.94 g sodium citrate in place of sodium bicarbonate per litre of oral rehydration rehydration solution. Efficacies were compared by measuring oral fluid intake, stool and vomitus output, change in body weight, hydration status, and rate of c...

  11. Sodium Bicarbonate Therapy in Patients with Metabolic Acidosis

    Adeva-Andany, María M.; Carlos Fernández-Fernández; David Mouriño-Bayolo; Elvira Castro-Quintela; Alberto Domínguez-Montero

    2014-01-01

    Metabolic acidosis occurs when a relative accumulation of plasma anions in excess of cations reduces plasma pH. Replacement of sodium bicarbonate to patients with sodium bicarbonate loss due to diarrhea or renal proximal tubular acidosis is useful, but there is no definite evidence that sodium bicarbonate administration to patients with acute metabolic acidosis, including diabetic ketoacidosis, lactic acidosis, septic shock, intraoperative metabolic acidosis, or cardiac arrest, is beneficial ...

  12. 40 CFR 415.140 - Applicability; description of the sodium bicarbonate production subcategory.

    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...

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

    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...... therefore of significant interest to the scientific community. Herein we describe a short and efficient synthesis of S0859 with an overall yield of 45?% from commercially available starting materials. The inhibitory effect of S0859 on recovery of intracellular pH after an acid load was verified in human and...

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

    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.

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

    Walawska Barbara; Szymanek Arkadiusz; Pajdak Anna; Nowak Marzena

    2014-01-01

    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 i...

  16. Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

    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.)

  17. Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

    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.)

  18. 40 CFR 180.1176 - Sodium bicarbonate; exemption from the requirement of a tolerance.

    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...

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

    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.

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

    Kunther, W., E-mail: Wolfgang.Kunther@empa.ch [Empa, Laboratory for Concrete and Construction Chemistry, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Lothenbach, B. [Empa, Laboratory for Concrete and Construction Chemistry, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Scrivener, K. [EPFL, Laboratory of Construction Materials, CH-1015 Lausanne (Switzerland)

    2013-02-15

    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.

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

    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)

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

    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)

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

    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.

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

    NingYan

    2013-01-01

    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 t...

  5. Transformation of sodium bicarbonate and CO2 into sodium formate over NiPd nanoparticle catalyst

    Wang, Mengnan; Zhang, Jiaguang; Yan, Ning

    2013-01-01

    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 t...

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

    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.

  7. Magnesium bicarbonate as an in situ uranium lixiviant

    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

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

    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

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

    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.

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

    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

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

    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...

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

    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. Thecementitious material is simulated as calcium hydroxide mixed with inert material but with sodium hydroxide...

  13. Transformation of sodium bicarbonate and CO2 into sodium formate over NiPd nanoparticle catalyst.

    Wang, Mengnan; Zhang, Jiaguang; Yan, Ning

    2013-01-01

    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. PMID:24790945

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

    NingYan

    2013-09-01

    Full Text Available 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.

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

    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.

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

    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

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

    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....

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

    Milka L. Avramov Ivić

    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.

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

    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

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

    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

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

    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

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

    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.

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

    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)

  4. The use of sodium bicarbonate in oral hygiene products and practice.

    Newbrun, E

    1997-01-01

    Early dentifrices contained natural ingredients, mostly in coarse particle form, and were quite abrasive. Salts, either sodium chloride, sodium bicarbonate, or a mixture of both, have also been used for tooth cleaning because of their ready availability and low cost. Because of both their relatively low intrinsic hardness and their high solubility, another advantage is low abrasivity. Their biggest disadvantage is a salty, unpalatable taste. Many modern dentifrices that contain sodium bicarbonate, either as the sole abrasive or one of several, disguise the saltiness with flavoring and sweetening agents. An almost inverse relationship exists between the percentage of baking soda in a dentifrice and its abrasivity. Sodium bicarbonate has no anticaries activity per se but is compatible with fluoride. In high concentrations, sodium bicarbonate is bactericidal against most periodontal pathogens. Most clinical studies have not found significant differences in periodontal response to baking soda as compared with other commercial dentifrices, probably because of its rapid clearance from the gingival sulcus. Sodium bicarbonate may not be the "magic bullet" for curing dental diseases, but its safety (if ingested), low abrasivity, low cost, and compatibility with fluoride make it a consummate dentifrice ingredient. PMID:12017930

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

    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.......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...

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

    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 kgm(-2), 66.7 5.7 ml(kgm)(-1) completed 3 conditions in a double-blinded, crossover fashion: (a) Placebo (Pl; 20 g maltodextrin + 0.5 gkg(-1) maltodextrin), (b) Creatine (Cr; 20 g + 0.5 gkg(-1) maltodextrin), and (c) Creatine plus sodium bicarbonate (Cr + Sb; 20 g + 0.5 gkg(-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

  7. Survival after an amniotic fluid embolism following the use of sodium bicarbonate.

    Evans, Sorcha; Brown, Brigid; Mathieson, Matthew; Tay, Stan

    2014-01-01

    Amniotic fluid embolism (AFE) is a rare and potentially fatal complication of pregnancy. In this case report, we highlight the successful use of sodium bicarbonate in a patient with an AFE. We present a case of a 38-year-old mother admitted for an elective caesarean section. Following the delivery of her baby, the mother suffered a cardiac arrest. Following a protracted resuscitation, transoesophageal echocardiography demonstrated evidence of acute pulmonary hypertension, with an empty left ventricle and an over-distended right ventricle. In view of these findings and no improvement noted from on-going resuscitation, sodium bicarbonate was infused as a pulmonary vasodilator. Almost instantaneous return of spontaneous circulation was noted, with normalisation of cardiac parameters. We propose that in patients suspected with AFE and who have been unresponsive to advance cardiac life support measures, and where right ventricular failure is present with acidosis and/or hypercarbia, the use of sodium bicarbonate should be considered. PMID:24879737

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

    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.)

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

    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: 1.410.32 versus Group C: 1.500.38 mg/dl). SCr at day 2 was significantly lower in Group B than Group C (1.440.38 versus 1.600.5 mg/dl, p<0.05) and 1 month (1.280.27 versus 1.490.55 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)

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

    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)

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

    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)

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

    Brodersen, K

    2003-03-01

    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 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)

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

    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).

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

    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...

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

    '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 1C. The antagonists survived and their p...

  16. Use of Sodium Bicarbonate in Cardiac Arrest: Current Guidelines and Literature Review.

    Velissaris, Dimitrios; Karamouzos, Vassilios; Pierrakos, Charalampos; Koniari, Ioanna; Apostolopoulou, Christina; Karanikolas, Menelaos

    2016-04-01

    The aim of the review was to summarize the literature over the last 25 years regarding bicarbonate administration in out-of-hospital cardiac arrest. A PubMed search was conducted using the terms "bicarbonates" and "cardiac arrest", limited to human studies and reviews published in English (or at least with a meaningful abstract in English) in the last 25 years. Clinical and experimental data raised questions regarding the safety and effectiveness of sodium bicarbonate (SB) administration during cardiac arrest. Earlier advanced cardiac life support (ACLS) guidelines recommended routine bicarbonate administration as part of the ACLS algorithm, but recent guidelines no longer recommend its use. The debate in the literature is ongoing, but at the present time, SB administration is only recommended for cardiac arrest related to hypokalemia or overdose of tricyclic antidepressants. Several studies challenge the assumption that bicarbonate administration is beneficial for treatment of acidosis in cardiac arrest. At the present time, there is a trend against using bicarbonates in cardiac arrest, and this trend is supported by guidelines published by professional societies and organizations. PMID:26985247

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

    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.

  18. SODIUM BICARBONATE INFUSION: TO PREVENT CARDIAC SURGERY - ASSOCIATED ACUTE KIDNEY INJURY

    Ramesh

    2015-02-01

    Full Text Available OBJECTIVES: The incidence of cardiac surgery – associated acute kidney injury is 50% of patients and is associated with increased mortality and morbidity. This study aimed to determine if perioperative urinary and plasma alkalization with sodium bicarbonate infusion re duces the incidence of cardiac surgery – associated acute kidney injury. SETTING AND DESIGN: This study is double blind randomized control trial conducted at U N Mehta Institute of Cardiology and Research Center , India. METHOD S AND RESULT: A total of 140 pat ients scheduled to undergo elective cardiac surgery , who were at increased risk of development of cardiac surgery – associated acute kidney injury using recognized risk factors. Patients were randomly allocated to receive either sodium bicarbonate (n = 70 o r sodium chloride (n = 70 infusion , commencing at the start of anesthesia , in a dose of 4 mmol/kg over 24 hour. The primary outcome measure was the number of patients with development of CSA - AKI , defined as an increase in creatinine greater than 25% from baseline to peak value within the first three postoperative days. Significant differences among the groups in both plasma and urinary pH were achieved 6 hours after commencement of the infusion , and these changes persisted for more than 24 hours. A total o f 7 out of 70(10% patients in the sodium bicarbonate group and 16 out of 70(22.85% patients in the sodium chloride group developed acute kidney injury within the first three postoperative days with p value of 0.06 which is statistically not significant . There were also no significant differences in ventilation hours , ICU or hospital length of stay , or mortality. CONCLUSIONS: Perioperative alkalization of blood and urine using an infusion of sodium bicarbonate did not result in a decrease in the incidence of acute kidney injury in patients undergoing cardiac surgery. KEYWORDS: Acute kidney injury; Cardiac surgery; Cardiopulmonary bypass; Creatinine; outcome; Urinary output

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

    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

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

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

    for curious and live seahorses are traded for aquarium purpose especially in Europe and America (Vincent, 1996). Overexploitation brought down the wild population of seahorses by 25-75% during the short period of five years (Vincent, 1996). In the year... of detailed practical information on the administration of anaesthesia, the objective of the present study was to determine the efficacy of sodium bicarbonate for yellow seahorse, Hippocampus kuda. 2. Materials and Methods 2.1 Experimental animals...

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

    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)

  2. Sodium bicarbonate as prevention of metabolic acidosis in sheep submitted to experimental ruminal acidosis

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

    2014-01-01

    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, submitted 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 rume...

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

    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)

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

    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...

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

    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,...

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

    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.)

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

    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.

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

    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.

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

    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....

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

    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

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

    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

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

    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

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

    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 ...

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

    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)

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

    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

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

    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

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

    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.

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

    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 mgkg 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 mgkg of NaHCO3, 270 mgkg 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

  19. The activation/depassivation of nickel–chromium–molybdenum alloys in bicarbonate solution: Part I

    Electrochemical and surface analytical techniques (X-ray photoelectron and Auger spectroscopies) were used to characterize the influence of potential on the properties of the oxide film formed on the Hybrid BC-1 (a Ni–Cr–Mo) alloy in chloride solutions containing bicarbonate. In the passive region the film possesses the expected bilayer structure with a Cr(III)-dominated barrier layer containing mixed oxidation states of Mo and an outer dominantly-hydroxide layer. At more positive potentials the Cr/Mo content of the film decreases when bicarbonate is present and the alloy becomes covered by a thick (>100 nm), and only partially protective, Ni(OH)2 layer

  20. Evaluating the effects of caffeine and sodium bicarbonate, ingested individually or in combination, and a taste-matched placebo on high-intensity cycling capacity in healthy males.

    Higgins, Matthew F; Wilson, Susie; Hill, Cameron; Price, Mike J; Duncan, Mike; Tallis, Jason

    2016-04-01

    This study evaluated the effects of ingesting sodium bicarbonate (NaHCO3) or caffeine individually or in combination on high-intensity cycling capacity. In a counterbalanced, crossover design, 13 healthy, noncycling trained males (age: 21 ± 3 years, height: 178 ± 6 cm, body mass: 76 ± 12 kg, peak power output (Wpeak): 230 ± 34 W, peak oxygen uptake: 46 ± 8 mL·kg(-1)·min(-1)) performed a graded incremental exercise test, 2 familiarisation trials, and 4 experimental trials. Trials consisted of cycling to volitional exhaustion at 100% Wpeak (TLIM) 60 min after ingesting a solution containing either (i) 0.3 g·kg(-1) body mass sodium bicarbonate (BIC), (ii) 5 mg·kg(-1) body mass caffeine plus 0.1 g·kg(-1) body mass sodium chloride (CAF), (iii) 0.3 g·kg(-1) body mass sodium bicarbonate plus 5 mg·kg(-1) body mass caffeine (BIC-CAF), or (iv) 0.1 g·kg(-1) body mass sodium chloride (PLA). Experimental solutions were administered double-blind. Pre-exercise, at the end of exercise, and 5-min postexercise blood pH, base excess, and bicarbonate ion concentration ([HCO3(-)]) were significantly elevated for BIC and BIC-CAF compared with CAF and PLA. TLIM (median; interquartile range) was significantly greater for CAF (399; 350-415 s; P = 0.039; r = 0.6) and BIC-CAF (367; 333-402 s; P = 0.028; r = 0.6) compared with BIC (313: 284-448 s) although not compared with PLA (358; 290-433 s; P = 0.249, r = 0.3 and P = 0.099 and r = 0.5, respectively). There were no differences between PLA and BIC (P = 0.196; r = 0.4) or between CAF and BIC-CAF (P = 0.753; r = 0.1). Relatively large inter- and intra-individual variation was observed when comparing treatments and therefore an individual approach to supplementation appears warranted. PMID:26988768

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

    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

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

    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)

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

    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 110? 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

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

    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.

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

    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 sodiumpotassium 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.

  6. Expectancy of ergogenicity from sodium bicarbonate ingestion increases high-intensity cycling capacity.

    Higgins, Matthew F; Shabir, Akbar

    2016-04-01

    This study examined whether expectancy of ergogenicity of a commonly used nutritional supplement (sodium bicarbonate; NaHCO3) influenced subsequent high-intensity cycling capacity. Eight recreationally active males (age, 21 ± 1 years; body mass, 75 ± 8 kg; height, 178 ± 4 cm; WPEAK = 205 ± 22 W) performed a graded incremental test to assess peak power output (WPEAK), one familiarisation trial and two experimental trials. Experimental trials consisted of cycling at 100% WPEAK to volitional exhaustion (TLIM) 60 min after ingesting either a placebo (PLA: 0.1 g·kg(-1) sodium chloride (NaCl), 4 mL·kg(-1) tap water, and 1 mL·kg(-1) squash) or a sham placebo (SHAM: 0.1 g·kg(-1) NaCl, 4 mL·kg(-1) carbonated water, and 1 mL·kg(-1) squash). SHAM aimed to replicate the previously reported symptoms of gut fullness (GF) and abdominal discomfort (AD) associated with NaHCO3 ingestion. Treatments were administered double blind and accompanied by written scripts designed to remain neutral (PLA) or induce expectancy of ergogenicity (SHAM). After SHAM mean TLIM increased by 9.5% compared to PLA (461 ± 148 s versus 421 ± 150 s; P = 0.048, d = 0.3). Ratings of GF and AD were mild but ∼1 unit higher post-ingestion for SHAM. After 3 min TLIM overall ratings of perceived exertion were 1.4 ± 1.3 units lower for SHAM compared to PLA (P = 0.020, d = 0.6). There were no differences between treatments for blood lactate, blood glucose, or heart rate. In summary, ergogenicity after NaHCO3 ingestion may be influenced by expectancy, which mediates perception of effort during subsequent exercise. The observed ergogenicity with SHAM did not affect our measures of cardiorespiratory physiology or metabolic flux. PMID:26863442

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

    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.

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

    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.

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

    De Giusti, Vernica C; Orlowski, Alejandro; Ciancio, Mara C; Espejo, Mara S; Gonano, Luis A; Caldiz, Claudia I; Vila Petroff, Martn G; Villa-Abrille, Mara 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: 1005.82%, n=7 vs Ald: 151.8811.02%, n=5; P<0.05), which was prevented by G15 (GPR30 blocker, 90.537.81%, n=7). Further evidence for the involvement of GPR30 was provided by G1 (GPR30 agonist), which stimulated NBC (185.1318.28%, n=6; P<0.05) and this effect was abrogated by G15 (124.1910.96%, 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

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

    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

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

    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.

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

    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.

  13. Effect of sodium bicarbonate air abrasive polishing on resistance to sliding during tooth alignment and leveling: An in vitro study

    Jorge C. B. L. Filho

    2012-01-01

    Full Text Available Objective: The aim of this in vitro study was to evaluate the Resistance to Sliding (RS provided by metallic brackets and 3 types of orthodontic wires (TMA, SS and NiTi, before and after the use of sodium bicarbonate airborne particle abrasion, in an experimental model with 3 non leveled brackets. Materials and Methods: The bicarbonate airborne abrasion was applied perpendicularly to the bracket slots at a distance of 2 mm, for 5 seconds (T2 and 10 seconds (T3 on each bracket slot. In a universal testing machine, the wires were pulled through a set of 3 non leveled brackets at a cross head speed of 50 mm/min for a distance of 10 mm, and static and kinetic friction readings were registered at T1 (no airborne abrasion, T2 and T3. Results: For all tested wires, a significant RS increase between T1 and T3 (P<0.001 was seen. For SS and TMA wires, there was a statistically significant RS increase between T1 and T2 (P<0.001. Between T2 and T3, RS increase was significant for TMA (P<0.001 and NiTiwires (P<0.05. Conclusions: Sodium bicarbonate air abrasive polishing during orthodontic treatment is not recommended, once this procedure promoted a significant RS increase between the metallic brackets and all the three types of wires tested.

  14. 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

    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...

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

    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

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

    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...

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

    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

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

    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.

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

    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)

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

    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

  1. 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

    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.

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

    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)

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

    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)

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

    Stefnsson, Andri; Bnzeth, 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.

  5. 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

    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.

  6. The radiation chemistry of aqueous sodium terephthalate solutions

    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

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

    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 gkg(-1) of maltodextrin), 20 gd(-1) of creatine monohydrate + placebo, 0.3 gkg(-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 (Ws(-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 (Ws(-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

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

    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

  9. Evaluating Battery-like Reactions to Harvest Energy from Salinity Differences using Ammonium Bicarbonate Salt Solutions.

    Kim, Taeyoung; Rahimi, Mohammad; Logan, Bruce E; Gorski, Christopher A

    2016-05-10

    Mixing entropy batteries (MEBs) are a new approach to generate electricity from salinity differences between two aqueous solutions. To date, MEBs have only been prepared from solutions containing chloride salts, owing to their relevance in natural salinity gradients created from seawater and freshwater. We hypothesized that MEBs could capture energy using ammonium bicarbonate (AmB), a thermolytic salt that can be used to convert waste heat into salinity gradients. We examined six battery electrode materials. Several of the electrodes were unstable in AmB solutions or failed to produce expected voltages. Of the electrode materials tested, a cell containing a manganese oxide electrode and a metallic lead electrode produced the highest power density (6.3 mW m(-2) ). However, this power density is still low relative to previously reported NaCl-based MEBs and heat recovery systems. This proof-of-concept study demonstrated that MEBs could indeed be used to generate electricity from AmB salinity gradients. PMID:27030080

  10. Parametric study of reverse electrodialysis using ammonium bicarbonate solution for low-grade waste heat recovery

    Highlights: • We characterized the influence of various parameters on the NH4HCO3-RED system. • We found the best power density at the concentrated solutions of 1.5 mol L−1 and the diluted solution of 0.01 mol L−1. • We obtained the higher power density of 0.77 W m−2 than previous studies. - Abstract: Waste heat recovery has attracted a significant attention because of the world growth in energy demand. In this paper, we report the study on an energy recovery system utilizing low-grade waste heat below 100 °C. This system called a thermal-driven electrochemical generator is composed of reverse electrodialysis (RED) power generation and thermal separation using waste heat. We especially focus on the experimental characterization of the RED process with ammonium bicarbonate (NH4HCO3) solution, which is known to be easily decomposed at the temperature around 60 °C. We characterized this NH4HCO3-RED system with various parameters including the concentration difference, the membrane type, the inlet flow rate, and the compartment thickness. We found the best power density at the concentrated solution of 1.5 mol L−1 and the diluted solution of 0.01 mol L−1. The maximum power density increases as the inlet flow rate increases or the compartment thickness decreases owing to the decrease in the internal resistance. We obtained the excellent power density of 0.77 W m−2, compared with the previous studies

  11. Effects of sodium bicarbonate concentration on growth, photosynthesis, and carbonic anhydrase activity of macroalgae Gracilariopsis lemaneiformis, Gracilaria vermiculophylla, and Gracilaria chouae (Gracilariales, Rhodophyta).

    Zhou, Wei; Sui, Zhenghong; Wang, Jinguo; Hu, Yiyi; Kang, Kyoung Ho; Hong, Hye Ran; Niaz, Zeeshan; Wei, Huihui; Du, Qingwei; Peng, Chong; Mi, Ping; Que, Zhou

    2016-06-01

    There is potential for bicarbonate to improve crop yields and economic efficiency of marine algae. However, few studies have focused on the effect of bicarbonate on the growth, photosynthesis, and enzyme activity associated with carbon utilization, especially in commercial macroalgae. Here, the addition of bicarbonate (up to 420 mg L(-1)) to macroalgal cultures has been evaluated for Gracilariopsis lemaneiformis, Gracilaria vermiculophylla, and Gracilaria chouae with respect to growth rate, photosynthetic activity, carbonic anhydrase activity, and biochemical composition. The results showed that the effects of NaHCO3 on growth, chlorophyll a, phycoerythrin, photosynthetic oxygen evolution, photochemical parameters of PSI and PSII, carbonic anhydrase activity, and nitrogen content were significant (P 336 mg L(-1) for Gp. lemaneiformis and >420 mg L(-1) for the other two species). Moreover, species-specific differences induced by supplementation with bicarbonate were discovered during culture. Optimal concentrations of NaHCO3 used in this study were 252 mg L(-1) for Gp. lemaneiformis and 336 mg L(-1) for G. vermiculophylla and G. chouae. These results suggest that an adequate supplementation of sodium bicarbonate is a viable strategy for promoting growth and photosynthetic activity in some macroalgae as well as for improving biochemical composition. The study will help to accelerate the growth rate of algae and improve the quality of thalli, and will also be useful for enhancing the understanding of carbon utilization in macroalgae. PMID:26960545

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

    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)

  13. An evaluation of sodium bicarbonate chewing gum as a supplement to toothbrushing for removal of dental plaque from children's teeth.

    Kleber, C J; Davidson, K R; Rhoades, M L

    2001-07-01

    The purpose of this human clinical study was to determine whether a commercial chewing gum containing 5% sodium bicarbonate (ARM & HAMMER DENTAL CARE The Baking Soda Gum [AHDC]) was effective in removing dental plaque when used as a supplement to regular toothbrushing by children. Healthy children (N = 28, average age = 11 years) were randomly distributed into 2 groups. One group was instructed to chew 2 tablets of AHDC chewing gum for 20 minutes 2 times each day (after lunch and dinner) in addition to their normal toothbrushing regimen. The other group used a sugarless mint tablet twice daily during the same period in addition to toothbrushing. After 1 week of using their assigned product, all participants were again examined for oral health and plaque. After a 1-week washout period, subjects were crossed over to the opposite group. Among the 21 participants completing the study, the AHDC chewing gum significantly (P mint tablet control, as measured by the Modified Quigley-Hein Plaque Index. When longitudinally compared to the baseline plaque scores, the gum resulted in a significant (P mint tablets. In this study, regular use of AHDC chewing gum was safe and effective in removing dental plaque and served as a significant complement to the daily toothbrushing regimen of children. PMID:11913309

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

    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

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

    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

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

    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...

  17. Vanadium oxide dissolution in sodium carbonate solutions

    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.

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

    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 3g 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 3g 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

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

    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 760 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

  20. Desiliconization of commercial solutions of sodium tungstate

    A part of anolyte prepared in the process of soda regeneration from solutions of pressure soda leaching by the method of electrodialysis is proposed to be used for desiliconization of commercial solution of sodium tungstate. The purification technique consists in the anolyte adding in portions to a arbitrary volume of hot pressurized solution during two hour constant mixing up to pH value magnitude from 9 up to 8.5, the following two hour setting at 90 deg C, and filtration. The above purification technique does not introduce additional impurities to a solution used for WO3 separation

  1. Study of aqueous solutions of sodium linoleate

    Van der Linde, G.J. (Phosphate Development Corporation, Phalaborwa); Van Berge, P.C. (Rand Afrikaans Univ., Johannesburg (South Africa))

    1983-12-01

    During the development of a technique for measuring fatty acid absorption on finely divided minerals using a radiochemical method, absorption isotherms were obtained which displayed maxima. It was found that these results were due to the presence of stable micelles in the solutions. This has been established by measuring the surface tension, surface film pressure, and specific conductance of dilute aqueous solutions of sodium linoleate.

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

    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.

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

    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)

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

    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. ...

  5. Viscosity and density tables of sodium chloride solutions

    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)

  6. 21 CFR 184.1135 - Ammonium bicarbonate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium bicarbonate. 184.1135 Section 184.1135... Listing of Specific Substances Affirmed as GRAS § 184.1135 Ammonium bicarbonate. (a) Ammonium bicarbonate.... Crystals of ammonium bicarbonate are precipitated from solution and subsequently washed and dried. (b)...

  7. 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

    Tetens, Inge

    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...... 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...... dietary intake of carbonate or bicarbonate salts of sodium or potassium and maintenance of normal bone....

  8. Effect of bicarbonate on efficacy of oral rehydration therapy: studies in an experimental model of secretory diarrhoea.

    Elliott, E. J.; A.J. WATSON; Walker-Smith, J A; Farthing, M J

    1988-01-01

    In situ perfusion of rat intestine was used to evaluate the effect of bicarbonate on the efficacy of a low sodium (35 mmol/l) glucose-electrolyte oral rehydration solution in normal and cholera toxin-treated rat small intestine. In normal intestine, absorption of water was greater (108 (8.1) microliters/min/g; p less than 0.01) and sodium secretion less (-4.3 (0.3) mumol/min/g; p less than 0.01) from the oral rehydration solution containing bicarbonate than from the solution in which bicarbon...

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

    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.

  10. X-ray diffraction studies on merohedrally twinned Δ1–62NtNBCe1-A crystals of the sodium/bicarbonate cotransporter

    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 (Δ1–62NtNBCe1-A) are reported that diffract X-rays to 2.4 Å resolution. The crystal symmetry of Δ1–62NtNBCe1-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

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

    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 mlkg(-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

  12. Bicarbonate Test

    ... 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 ...

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

    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

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

    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?.

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

    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)

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

    . 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

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

    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. Effects of pH, sodium bicarbonate, cryoprotectants and foetal bovine serum on the cryopreservation of European eel sperm.

    Garzón, D L; Peñaranda, D S; Pérez, L; Marco-Jiménez, F; Espert, X; Müller, T; Jover, M; Asturiano, J F

    2008-02-01

    The main objective of the present study was to evaluate the influence of pH and bicarbonate concentration in the activation or inhibition of European eel (Anguilla anguilla) spermatozoa and to evaluate the effect of different cryoprotectants: dimethyl sulphoxide (DMSO), acetamide, ethylene glycol, propanol, glycerol and methanol (MeOH). The effect of these factors was evaluated comparing the percentage of motile cells, the percentage of alive cells (by Hoechst staining) and the spermatozoa morphometry pre- and post-cryopreservation (by computer-assisted morphology analysis). Based on the above findings, three cryoprotectants (DMSO, MeOH and glycerol) were chosen and evaluated in two media (P1 and P1 modified) with different concentrations of NaHCO(3) and in the presence or absence of foetal bovine serum (FBS). The effect of these factors was evaluated comparing the percentage of alive and motile cells post-cryopreservation. DMSO was the cryoprotectant showing better results in relation to the percentage of spermatic alive cells post-freezing and caused a smaller modification of the head spermatozoa morphology. The combination of P1-modified medium with DMSO and containing FBS increased slightly but significantly the percentage of motile spermatozoa post-cryopreservation. PMID:18199265

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

    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

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

    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 33 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

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

    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

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

    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 ΔS/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 Β5deg = 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

  3. 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

    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

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

    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).

  5. Effect of sodium bicarbonate and varying concentrations of sodium chloride in brine on the liquid retention of fish (Pollachius virensL.) muscle

    Åsli, Magnus; Ofstad, Ragni; Böcker, Ulrike; Jessen, Flemming; Einen, Olai; Mørkøre, Turid

    2016-01-01

    BACKGROUND Negative health effects associated with excessive sodium (Na) intake have increased the demand for tasty low-Na products (<2% NaCl) rather than traditional heavily salted fish products (∼20% NaCl). This study investigates the causes of improved yield and liquid retention of fish muscle...

  6. Bicarbonate exporting transporters in the ovine ruminal epithelium.

    Bilk, S; Huhn, K; Honscha, K U; Pfannkuche, H; Gbel, 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

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

    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

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

    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

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

    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.)

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

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

    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...

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

    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

  12. The electrogenicity of the rat sodium-bicarbonate cotransporter NBCe1 requires interactions among transmembrane segments of the transporter.

    Choi, Inyeong; Soo Yang, Han; Boron, Walter F

    2007-01-01

    The electrogenic Na+-HCO3- cotransporter (NBCe1) plays a central role in intracellular pH (pHi) regulation as well as HCO3- secretion by pancreatic ducts and HCO3- reabsorption by renal proximal tubules. To understand the structural requirements for the electrogenicity of NBCe1, we constructed chimeras of NBCe1-A and the electroneutral NBCn1-B, and used two-electrode voltage clamp to measure electrogenic transporter current in Xenopus oocytes exposed to 5% CO2-26 mm HCO3- (pH 7.40). The chimera consisting of NBCe1-A (i.e. NBCe1-A 'background') with the cytoplasmic N-terminal domain (Nt) of NBCn1-B had a reversal potential of -156.3 mV (compared with a membrane potential Vm of -43.1 mV in a HCO3(-)-free solution) and a slope conductance of 3.0 microS (compared with 12.5 microS for NBCe1-A). Also electrogenic were chimeras with an NBCe1-A background but with NBCn1-B contributing the extracellular loop (L) between transmembrane segment (TM) 5 and 6 (-140.9 mV/11.1 microS), the cytoplasmic C-terminal domain (Ct; -123.8 mV/9.7 microS) or Nt + L + Ct (-120.9 mV/3.7 microS). Reciprocal chimeras (with an NBCn1 background but with NBCe1 contributing Nt, L, Ct or Nt + L + Ct) produced no measurable electrogenic transporter currents in the presence of CO2-HCO3-. pHi recovered from an acid load, but without the negative shift of Vm that is characteristic of electrogenic Na+-HCO3- cotransporters. Thus, these chimeras were electroneutral, as were two others consisting of NBCe1(Nt-L)/NBCn1(TM6-Ct) and NBCn1(Nt-L)/NBCe1(TM6-Ct). We propose that the electrogenicity of NBCe1 requires interactions between TM1-5 and TM6-13. PMID:17038436

  13. On vanadium oxide dissolution in sodium carbonate solutions

    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

  14. Radiolysis of aqueous solutions of sodium sulfides. Chapter 8

    To study the radiolysis of the aqueous solutions of sodium sulphide, use was made of infrared spectroscopy, mass-spectrometry and iodometric titration. During the γ-irradiation of the aqueous solutions of sodium sulphide one can observe the appearance of various stable sulphur-containing products. Data are discussed on the radiolysis in a nitrous environment, on oxygen bubbling, at varying radiation doses, pH and temperature values. Consideration is also given to the low-temperature radiolysis of the aqueous solutions of sodium sulphide by the EPR method. In the radiolysis of both crystalline and glassy solutions of Na2S there appear an ion-radical S- and a radical SO2-

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

    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. Sodium Hydroxide Extraction From Caustic Leaching Solutions

    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.

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

    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.

  18. Kinetics of sodium borohydride hydrolysis in aqueous-basic solutions

    Retnamma, Rajasree; Rangel, C. M.; Novais, Augusto Q.; Matthews, Michael A.

    2013-01-01

    Liquid-phase catalytic hydrolysis of sodium borohydride (NaBH4) for hydrogen production necessitates long-term stability of base-stabilized NaBH4 solutions at higher temperatures. The present paper reports the kinetics of aqueous-basic solutions containing 20 wt% NaBH4 with 1-15 wt% sodium hydroxide (NaOH) at 80 0C. The established kinetic model employs a modified isoconversional method assuming single-step kinetics. The estimation of kinetic parameters is performed by gPROMS (general PRocess...

  19. Solubility of sodium soaps in aqueous salt solutions.

    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].

    Hoffmanov, 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. Lead sulphate leaching by sodium chloride solution

    Conić Vesna T.; Pešovski Branka D.; Cvetkovski Vladimir B.; Stanojević-Šimšić Zdenka S.; Dragulović Suzana S.; Simonović Danijela B.; Dimitrijević Silvana B.

    2013-01-01

    Bioleaching treatment of complex multi-metallic Cu-Zn-Pb-Ag-Au mineral concentrates leds to the formation, besides easily soluble zinc and cooper sulphates, of hardly soluble lead (II) sulfate (PbSO4) sludge. To determine the leaching parameters of PbSO4 with NaCl in the bioleaching residue, lead sulphate solution was synthetically prepared. The effect of process parameters, namely NaCl concentration, solid:liquid phase ratio, processing time, temperature and Cl ions was examined. It wa...

  2. Lead sulphate leaching by sodium chloride solution

    Conić Vesna T.

    2013-01-01

    Full Text Available Bioleaching treatment of complex multi-metallic Cu-Zn-Pb-Ag-Au mineral concentrates leds to the formation, besides easily soluble zinc and cooper sulphates, of hardly soluble lead (II sulfate (PbSO4 sludge. To determine the leaching parameters of PbSO4 with NaCl in the bioleaching residue, lead sulphate solution was synthetically prepared. The effect of process parameters, namely NaCl concentration, solid:liquid phase ratio, processing time, temperature and Cl ions was examined. It was found that 100% Pb by leaching can be achieved with NaCl concentration of 250 g/dm3, time 20 min, temperature 353 K and solid:liquid phase ratio =1:20.

  3. BY THE MECHANOACTIVATION OF SOLUTION OF THE SODIUM SILICATE

    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.

  4. A study of aqueous solutions of sodium linoleate

    During the development of a technique for measuring fatty acid absorption on finely divided minerals using a radiochemical method, absorption isotherms were obtained which displayed maxima. It was found that these results were due to the presence of stable micelles in the solutions. This has been established by measuring the surface tension, surface film pressure, and specific conductance of dilute aqueous solutions of sodium linoleate

  5. Sodium silicate solutions from dissolution of glass wastes. Statistical analysis

    Torres-Carrasco, M., Palomo, A.,; Puertas, F.

    2014-01-01

    [EN]It has studied the solubility process of four different waste glasses (with different particle sizes, 125 μm) in alkaline solutions (NaOH and NaOH/Na2CO3) 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 (

  6. Ionization of methyl orange in aqueous sodium chloride solutions

    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 molkg?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.

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

    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)

  8. Substituted sodium phenylanthranylates as inhibitors of corrosion in chloride solutions

    Kuznetsov, Yu.I.; Fialkov, Yu.A.; Popova, L.I.; Ehndel' man, E.S.; Kuznetsova, I.G. (AN SSSR, Moscow. Inst. Fizicheskoj Khimii)

    The efficiency of corrosion protection of armco iron, zinc (Ts-O) aluminium (AB 000) and its alloys (.D16 and AMG6) with sodium phenylanthranylate derivatives in chloride buffer solutions (pH 7.4-8.08) are investigated. It has been ascertained that the introduction of sodium phenylanthranylate into phenyl radical in m- and p-position relative to the amino group of electron-seeking substitutes improves protective properties of an inhibitor. The inhibiting effect of phenylanthranylates and its dependence on electron structure enchances in zinc-aluminium-iron series and decreases in case of transition from pure aluminium to its alloys.

  9. An evaluation of the behaviour of high alumina cement mortars in dilute sulphuric acid, sodium sulphate and sodium chloride solutions

    This investigation was aimed at evaluating the behaviour of high alumina cement (HAC) mortars in 1 per cent sulphuric acid, 5 per cent sodium sulphate and 3 per cent sodium chloride solutions at 5 degrees Celsius, 22 degrees Celsius and 40 degrees Celsius. The influence of conversion of HAC on the behaviour in aggressive solutions of mortars made with it was evaluated. The mortars in which the HAC was unconverted were much less pervious than the ones in which it was converted. Although ettringite was formed in the mortars that were exposed to the sulphate solution, little expansion resulted during one year of exposure. The mortars that were exposed to the chloride solution, showed no expansion. Both in the sodium sulphate solution and in the sodium chloride solution, sodium hydroxide was produced by reaction between the calcium aluminates and the sodium salts; this can eventually lead to deterioration

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

    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.

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

    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.)

  12. A thermochemical study of aqueous solutions of sodium naproxene

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

    2009-02-01

    The enthalpies of solution of sodium naproxene and dilution of its aqueous solutions were measured on an isoperibolic calorimeter at 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15 K. The maximum content of the electrolyte was determined by its solubility at the given temperature (0.038-0.083 mol/kg solvent). The Pitzer model was used to obtain the virial coefficients for calculations of many excess thermodynamic properties of both solutions and their components. Changes in these characteristics depending on the concentration and temperature are considered.

  13. 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

    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.

  14. Study of sodium borohydride solubility in aqueous ammonia solutions

    A study was made on NaBH4 solubility in aqueous-ammonia mixtures in NH3 concentration range of 10-35 mass% at temperatures of 22, -5 and -9 deg C. Crystallization fields of nonsolvated sodium borohydride and its dihydrate NaBH4 · 2H2O were determined. Metastable region oversaturated solutions, coexisting either with NaBH4 · 2H2O, or with NaBH4 · H2O, depending on ammonia temperature and concentration was established in the system. Solubility of sodium borohydride in aqueous ammonnia increases with growth of temperature and ammonia content in the solution in the whole analyzed temperature and concentation range

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

    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

  16. Radiolytic oxidation behavior of neptunium in sodium chloride solutions

    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 (194)[H] mol/dm3/d. (author)

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

    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)231NaOH(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. Ternary diffusion of carbon dioxide in alkaline solutions of aqueous sodium hydroxide and aqueous sodium carbonate

    Leaist, D.G.

    1985-07-01

    Carbon dioxide dissolved in alkaline solutions diffuses as bicarbonate and carbonate ions produced by the reactions CO/sub 2/+OH/sup -/=HCO/sub 3//sup -/ and CO/sub 2/+2OH/sup -/=CO/sub 3//sup 2 -/+H/sub 2/O. Ternary diffusion coefficients of the systems NaHCO/sub 3/+Na/sub 2/CO/sub 3/+H/sub 2/O and Na/sub 2/CO/sub 3/+NaOH+H/sub 2/O have been measured by a conductimetric technique at 298.15 K. The mixed electrolyte data are transformed by use of the solution equilibria to ternary diffusion coefficients of the systems CO/sub 2/+Na/sub 2/CO/sub 3/+H/sub 2/O and CO/sub 2/+NaOH+H/sub 2/O. Unlike the binary diffusivity of CO/sub 2/ in water (1.9 . 10/sup -9/ m/sup 2/ s/sup -1/), the ternary diffusivity of CO/sub 2/ in alkaline solutions is sensitive to concentration and varies from 0.9 . 10/sup -9/ to 3.5 . 10/sup -9/ m/sup 2/ s/sup -1/ at 298.15 K. Expressions are derived to estimate the transport coefficients of the components from the concentrations and diffusion coefficients of the constituent ions. At high pH values hydroxide-coupled transport leads to rapid diffusion of CO/sub 2/ as CO/sub 3//sup 2 -/. The results are consistent with the Onsager reciprocal relation for isothermal ternary diffusion.

  19. Expression and/or activity of the SVCT2 ascorbate transporter may be decreased in many aggressive cancers, suggesting potential utility for sodium bicarbonate and dehydroascorbic acid in cancer therapy.

    McCarty, Mark F

    2013-10-01

    Hypoxia-inducible factor-1 (HIF-1) is a heterodimer transcription factor whose elevated activity in many cancers helps them to survive under hypoxic conditions and enhances their capacity to grow invasively, establish metastases, and survive chemo- or radiotherapy. Optimal intracellular levels of ascorbate suppress the level and transcriptional activity of HIF-1under normoxic or mildly hypoxic conditions by supporting the activity of proly and asparagyl hydroxylases that target HIF-1alpha. High intracellular ascorbate can also work in various ways to down-regulate activation of NF-kappaB which, like HIF-1 is constitutively active in many cancers and promotes aggressive behavior - in part by promoting transcription of HIF-1alpha. Yet recent evidence suggests that, even in the context of adequate ascorbate nutrition, the intracellular ascorbate content of many aggressive cancers may be supoptimal for effective HIF-1 control. This likely reflects low expression or activity of the SVCT2 ascorbate transporter. The expression of SVCT2 in cancers has so far received little study; but the extracellular acidity characteristic of many tumors would be expected to reduce the activity of this transporter, which has a mildly alkaline pH optimum. Unfortunately, since SVCT2 has a high affinity for ascorbate, and its activity is nearly saturated at normal healthy serum levels of this vitamin, increased oral administration of ascorbate would be unlikely to have much impact on the intracellular ascorbate content of tumors. However, cancers in which HIF-1 is active express high levels of glucose transporters such as GLUT-1, and these transporters can promote influx of dehydroascorbic acid (DHA) via facilitated diffusion; once inside the cell, DHA is rapidly reduced to ascorbate, which effectively is "trapped" within the cell. Hence, episodic intravenous infusions of modest doses of DHA may have potential for optimizing the intracellular ascorbate content of cancers, potentially rendering them less aggressive. Indeed, several published studies have concluded that parenteral DHA--sometimes in quite modest doses--can retard the growth of transplanted tumors in rodents. As an alternative or adjunctive strategy, oral administration of sodium bicarbonate, by normalizing the extracellular pH of tumors, has the potential to boost the activity of SCTV2 in tumor cells, thereby promoting increased ascorbate uptake. Indeed, the utility of oral sodium bicarbonate for suppressing metastasis formation in nude mice xenografted with a human breast cancer has been reported. Hence, oral sodium bicarbonate and intravenous DHA may have the potential to blunt the aggressiveness of certain cancers in which suboptimal intracellular ascorbate levels contribute to elevated HIF-1 activity. PMID:23916956

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

    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

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

    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

  2. Soret diffusion processes in aqueous sodium chloride solutions

    Cygan, R.T.

    1985-01-01

    The mass transport of chemical species induced by a temperature gradient, commonly known as Soret diffusion, has been examined for the case of the sodium chloride and water system. The occurrence of significant thermal gradients in geological media, especially those associated with radioactive waste disposal sites, can produce a measurable flux of sodium chloride and therefore enrich the local solutions. Soret coefficients, or the ratio of thermal to isothermal mass transport factors, describe this rate of mass transfer and are necessary for evaluating certain nonequilibrium processes, such as the migration of fluid inclusions in rock salt. Experimental Soret coefficients for the NaCl-H/sub 2/O system were obtained by the use of a conductimetric thermal diffusion cell. This approach relies on monitoring the electrical conductivity change of two separate isothermal reservoirs which are maintained at different temperatures. The Soret cell is situated between the reservoirs and is comprised of an inert matrix of glass beads in order to minimize any solution convection. The utilization of this porous medium requires corrections for porosity and tortuosity. Measurements were made for 0.1 and 1.0 N NaCl solutions at mean temperatures of 40/sup 0/C and 50/sup 0/C with the mass transport induced by a thermal gradient of 2.6/sup 0/C/cm. The preliminary results indicate a Soret separation on the order of 1 to 2 percent with the attainment of a steady state in approximately 15 hours.

  3. Modeling of self-gydrolysis of concentrated sodium borohydride solution

    Retnamma, Rajasree; Rangel, C. M.; Novais, Augusto Q.; Yu, LIn; Matthews, Michael A.

    2010-01-01

    In spite of the US DOE recommendation of no-go for sodium borohydride for on-board vehicular hydrogen storage, a great deal of interest remains particularly with view to portable applications. In this work we report on experimental and modeling studies of the kinetics of self-hydrolysis of concentrated NaBH4 solutions (10 – 20 wt %) for temperatures varying between 25 – 80 0C, based on 11B NMR study. The models studied were a power law model and a model which describes the change in order of ...

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

    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

  5. Efeitos da correo da acidose metablica com bicarbonato de sdio sobre o catabolismo protico na insuficincia renal crnica The effects of the correction of metabolic acidosis with sodium bicarbonate on protein catabolism in chronic kidney failure

    Denise MAFRA

    2001-04-01

    Full Text Available A desnutrio protico-energtica constitui problema comum aos pacientes com insuficincia renal crnica, influenciando diretamente na sua morbi-mortalidade. A acidose metablica tem papel no catabolismo protico, ativando a via proteoltica proteasoma-ubiquitina, dependente de adenosina trifosfato, e conjuntamente com glicocorticides induz uma maior atividade na desidrogenase que degrada os aminocidos de cadeia ramificada. Esta reviso teve como objetivo descrever o mecanismo pelo qual a acidose metablica nos pacientes com insuficincia renal crnica promove o catabolismo protico, favorecendo assim a desnutrio, bem como avaliar os efeitos do uso de bicarbonato de sdio na correo da acidose e conseqentemente reduo do catabolismo protico. Pesquisas mostram melhora da acidose pelo uso de bicarbonato de sdio e conseqente reduo do catabolismo protico na insuficincia renal crnica, podendo ser esta uma conduta promissora na atenuao da desnutrio 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.

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

    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.

  7. Visco-Elastic Properties of Sodium Hyaluronate Solutions

    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. Modified sodium diuranate process for the recovery of uranium from uranium hexafluoride transport cylinder wash solution

    Meredith, Austin Dean

    Uranium hexafluoride (UF6) containment cylinders must be emptied and washed every five years in order to undergo recertification, according to ANSI standards. During the emptying of the UF6 from the cylinders, a thin residue, or heel, of UF6 is left behind. This heel must be removed in order for recertification to take place. To remove it, the inside of the containment cylinder is washed with acid and the resulting solution generally contains three or four kilograms of uranium. Thus, before the liquid solution can be disposed of, the uranium must be separated. A modified sodium diuranate (SDU) uranium recovery process was studied to support development of a commercial process. This process was sought to ensure complete uranium recovery, at high purity, in order that it might be reused in the nuclear fuel cycle. An experimental procedure was designed and carried out in order to verify the effectiveness of the commercial process in a laboratory setting. The experiments involved a small quantity of dried UO2F2 powder that was dosed with 3wt% FeF3 and was dissolved in water to simulate the cylinder wash solution. Each experiment series started with a measured amount of this powder mixture which was dissolved in enough water to make a solution containing about 120 gmU/liter. The experiments involved validating the modified SDU extraction process. A potassium diuranate (KDU) process was also attempted. Very little information exists regarding such a process, so the task was undertaken to evaluate its efficacy and determine whether a potassium process yields any significant differences or advantages as compared to a sodium process. However, the KDU process ultimately proved ineffective and was abandoned. Each of the experiments was organized into a series of procedures that started with the UO2F2 powder being dissolved in water, and proceeded through the steps needed to first convert the uranium to a diuranate precipitate, then to a carbonate complex solution, and finally to a uranyl peroxide (UO4) precipitate product. Evaluation of operating technique, uranium recovery efficiency, and final product purity were part of each experiment. Evaluation of a technique for removing fluoride from the diuranate precipitation byproduct filtrate using granular calcite was also included at the end of the uranium recovery testing. It was observed that precipitation of sodium diuranate (SDU) was very nearly complete at a pH of 11-12, using room temperature conditions. Uranium residuals in the filtrate ranged from 3.6 - 19.6 ppm, meaning almost complete precipitation as SDU. It was postulated and then verified that a tailing reaction occurs in the SDU precipitation, which necessitates a digestion period of about 2 hours to complete the precipitation. Further, it was shown, during this phase of the process, that a partial precipitation step at pH 5.5 did not adequately separate iron contamination due to an overlap of uranium and iron precipitations at that condition. Carbonate extraction of the SDU required an extended (3-4 hours) digestion at 40°C and pH 7-8 to complete, with sodium bicarbonate found to be the preferred extractant. The carbonate extraction was also proven to successfully separate the iron contamination from the uranium. Potassium-based chemistry did produce a potassium diuranate (KDU) analogue of SDU, but the subsequent carbonate extraction using either potassium bicarbonate or potassium carbonate proved to be too difficult and was incomplete. The potassium testing was terminated at this step. The uranyl peroxide precipitation was found to operate best at pH 3.5 - 4.0, at room temperature, and required an expected, extended digestion period of 8 -10 hours. The reaction was nearly complete at those conditions, with a filtrate residual ranging from 2.4 to 36.8 ppmU. The uranyl peroxide itself was very pure, with impurity averages at a very low 0.8 ppmNa and 0.004 ppmFe. ASTM maximum levels are 20 ppmNa and 150 ppmFe. Fluoride removal from the SDU precipitation filtrate required multiple passes of the solution through a calcite bed with acid additions to adjust the pH back down to below 6 before each pass to allow the removal reaction to proceed. This result was a modification of the single pass technique that was planned due to the apparent shutdown of the NaF/calcite reaction at pH above about 10. Conclusions drawn from the testing were that the results demonstrated a workable and effective series of processing steps. Techniques developed from the tests will make uranium recovery viable when transferred to the commercial process design.

  9. Radiolysis of sodium p-cumenesulfonate in aqueous solution

    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

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

    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

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

    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.

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

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

    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...

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

    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.

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

    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...

  16. 21 CFR 520.563 - Diatrizoate meglumine and diatrizoate sodium oral solution.

    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...

  17. Pulse and steady-state radiolysis of sodium tetraphenylborate solutions

    Major products and their G-Values from Co-60 gamma radiolysis of 0.05 M sodium tetraphenylborate (NaTPB) at 25 degrees C are hydrogen (0.46), biphenyl (2.0), benzene (1.3), and phenol (0.41). A dose of 4.4 Mrad increased the pH from 8.2 (initial) to 9.2. Reactions of transient species in aqueous TPB- solutions were studied by electron pulse radiolysis. The lack of reactivity between TPB- and eaq- was shown by monitoring was shown by monitoring the transient optical absorbance of eaq-. The results suggests that OH+ addition is the main reaction pathway. Using N2O saturation, the authors found k = 6.2x109 M-1s-1. A mechanism based on an initial 1st order decomposition of the OH+ adduct, (C6H5)3BC6H5OH-., with a measured rate constant of 4x104 s-1 is proposed. Kinetic modeling based on the proposed mechanistic scheme gives good agreement with experimental results

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

    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/Na₂CO₃ 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/Na₂CO₃ 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/Na₂CO₃ 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 ²⁹Si 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.

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

    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

    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 th...

  1. Uptake of ozone to mixed sodium bromide/ citric acid solutions

    Lee, Ming-Tao; Steimle, Emilie; Bartels-Rausch, Thorsten; Kato, Shunsuke; Lampimäki, Markus; Brown, Matthew; van Bokhoven, Jeroen; Nolting, Frithjof; Kleibert, Armin; Türler, Andreas; Ammann, Markus

    2013-04-01

    Sea-salt solution - air interfaces play an important role in the chemistry of the marine boundary layer. The reaction of ozone (O3) with bromide is of interest in the context of formation of photolabile halogens (Br2, BrCl) in the marine boundary layer. Recent experiments have suggested that the bromide oxidation rate is related to the surface concentration of bromide [1] and inversely related to the gas phase concentration of O3, an indication for a precursor mediated reaction at the surface [2]. So far, the effect of organics (such as those occurring at the ocean surface or in marine aerosols) on the reaction of O3 with bromide aerosols has not been studied yet. In our study we investigate the uptake kinetics of O3 to a mixed solution of sodium bromide (NaBr) and citric acid (CA), which represents highly oxidized organic compounds present in the environment, with a well-established coated wall flow tube technique, which leads to exposure of the film to O3 allowing the heterogeneous reactions to take place and the loss of O3 being measured. The results indicate that the uptake of O3 to the films with the higher bromide concentrations (0.34M and 4M) is independent of the gas phase concentration and roughly consistent with uptake limited by reaction in the bulk. For the lower bromide concentration (84mM), however, we observe a trend of the uptake coefficient to decrease with increasing O3 concentration, indicating an increasing importance of a surface reaction. In an attempt to constrain the kinetic data, we employed X-ray photoelectron spectroscopy (XPS) to get insight into the surface composition of the aqueous solution - air interface. Previous XPS studies have shown that halide ion concentrations are enhanced at the aqueous solution air interface [3-4], which likely promotes the surface reactions of bromide or iodide with O3. A first XPS study of ternary solutions of KI with butanol indicated the importance of specific interactions of the cation with the alcohol headgroup [5]. In this study we would like to go one step further and look into the effect of a more complex organic compound, CA. We used ambient pressure XPS on a vacuum liquid microjet. The continuously refreshed free-flowing aqueous filament under vacuum permits photoelectron spectroscopy measurements from volatile aqueous interfaces in absence of beam damage [6]. Measurements were made at the SIM beam line of the Swiss Light Source (SLS) at the Paul Scherrer Institute. The ability to tune the photon energy (150-2000 eV) is crucial to get precise component ratios as a function of photoelectron kinetic energy and thus probe depth, thus allowing to determine relative concentrations of citric acid and bromide at the surface and in the bulk, respectively. REFERENCES [1] Clifford and Donaldson, J. Phys. Chem. A, 111, 9809-9814, (2007). [2] Oldridge and Abbatt, J. Phys. Chem. A, 115, 2590-2598, (2011). [3] S. Ghosal et al., Science 307, 563 (2005). [4] M.A. Brown et al., Phys. Chem. Chem. Phys. 10, 4778 (2008). [5] M. Krisch et al., J. Phys. Chem. C 111, 13497 (2007). [6] M.A. Brown et al., J. Phys. Chem. Lett. 3, 231 (2012).

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

    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

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

    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)

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

    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)

  5. Maximizing adhesion of auxin solutions to stem cuttings using sodium cellulose glycolate

    Auxin solutions prepared with sodium cellulose glycolate (SCG; a thickening agent, also known as sodium carboxymethylcellulose) and applied to stem cuttings using a basal quick-dip extend the duration of exposure of cuttings to the auxin and have previously been shown to increase root number and/or ...

  6. Effect of peroxodisulfate on uranium leaching with ammonium bicarbonate

    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...

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

    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.

  8. Ion exchange reactions in interaction of basic zirconium sulfate with sodium carbonate solution

    Basic zirconium sulfates, extracted from basic zirconium chloride solution and zirconium disulfate solution, as well as products of their interaction with sodium carbonate solution, which was exposed and not exposed to hydrolysis, were investigated by chemical and NMR spectroscopy methods. It has been established that the process of interaction of the basic zirconium sulfate with sodium carbonate solutions sulfatocarbonatozicrconates and carbonatozirconates of sodium are sequentially formed. In this case carbonate groups, due to different strenght of addition of hydroxogroups in initial basic sulfates, substitute either SOsub(h)sup(2)-)- groups and H2O or SO42--and OH--groups, and sodium ions substitute H3O+-groups. Carbonate groups, if they have substituted sulfato- or hydroxogroup, during hydrolysis of carbonatozirconates are splitted out to a less degree

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

    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

  10. The vapour pressures over saturated aqueous solutions of DL-2-aminobutyric acid, 4-aminobutyric acid, sodium-D-gluconate, sodium hippurate, and potassium magnesium-L-aspartate

    Vapour pressures of water over saturated solutions of DL-2-aminobutyric acid, 4-aminobutyric acid, sodium-D-gluconate, sodium hippurate, and potassium magnesium-L-aspartate were determined over the (278 to 322) K temperature range. The determined vapour pressures were used to obtain the water activities, the molar enthalpies of vaporization, and the osmotic coefficients of sodium-D-gluconate

  11. The vapour pressures over saturated aqueous solutions of DL-2-aminobutyric acid, 4-aminobutyric acid, sodium-D-gluconate, sodium hippurate, and potassium magnesium-L-aspartate

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

    2008-05-15

    Vapour pressures of water over saturated solutions of DL-2-aminobutyric acid, 4-aminobutyric acid, sodium-D-gluconate, sodium hippurate, and potassium magnesium-L-aspartate were determined over the (278 to 322) K temperature range. The determined vapour pressures were used to obtain the water activities, the molar enthalpies of vaporization, and the osmotic coefficients of sodium-D-gluconate.

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

    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

  13. Confinement-induced vitrification of aqueous sodium chloride solutions

    Zhao, Lishan; Pan, Liqing; Cao, Zexian; Wang, Qiang

    2016-03-01

    Bulk aqueous solution of NaCl is a poor glass former, it vitrifies only under high pressure. Here we report the investigation of glass transition of NaCl solutions confined in nanopores. By inspecting the dependence of glass transition temperature and heat flow jump at transition it is concluded that vitrification of confined NaCl solutions involves only the eutectic phase and the precipitated ice core may help furnish the demanded confinement strength. Ion-water interaction still plays a dominant role in determining vitrification of solutions even under nano-confinement, as under exactly the same confinement conditions vitrification of aqueous KCl solutions was not detected.

  14. Evaluation of photosynthetic efficacy and CO2 removal of microalgae grown in an enriched bicarbonate medium

    Abinandan, S.; Shanthakumar, S.

    2016-01-01

    Bicarbonate species in the aqueous phase is the primary source for CO2 for the growth of microalgae. The potential of carbon dioxide (CO2) fixation by Chlorella pyrenoidosa in enriched bicarbonate medium was evaluated. In the present study, effects of parameters such as pH, sodium bicarbonate concentration and inoculum size were assessed for the removal of CO2 by C. pyrenoidosa under mixotrophic condition. Central composite design tool from response surface methodology was used to validate st...

  15. Radiation-induced evolution of gas in neutral and alkaline aqueous solutions of sodium nitrate and sodium acetate simulating liquid radioactive wastes

    Gas release in neutral and alkaline aqueous solutions of sodium nitrate and sodium acetate, simulating liquid radioactive wastes, is studied. Yields of hydrogen, methane, carbon dioxide and nitrogen-containing gases are determined in dependence on the solution composition. Possible sources of these gases formation are discussed

  16. Radiation protection by ascorbic acid in sodium alginate solutions

    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 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)

  17. Radiation protection by ascorbic acid in sodium alginate solutions

    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)

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

    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

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

    aleti? 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...

  20. Synergistic hydrogen generation from aluminum, aluminum alloys and sodium borohydride in aqueous solutions

    Soler Turu, Lluis; Macanás de Benito, Jorge; Muñoz Tapia, Maria; Casado Giménez, Juan

    2007-01-01

    A new method to produce high purity hydrogen using reactions of aluminum and sodium borohydride with aqueous alkaline solutions is described. This process mainly consumes water and aluminum (or its alloys) which are cheaper raw materials than the borohydride. As a consequence, this process could be competitive for in situ production of hydrogen. Moreover, a synergistic effect has been observed in hydrogen production rates and yields combining aluminum or aluminum alloys with sodium borohydrid...

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

    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)

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

    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

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

    Shivaji S. Bidwe; Ajay A. Hamane

    2015-01-01

    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 Concret...

  4. Diffusion of sodium alginate in aqueous solutions at T = 298.15 K

    Highlights: • Mutual diffusion coefficients of sodium alginate in aqueous solutions. • Influence of the thermodynamic and kinetic factors on the variation of the mutual diffusion coefficients. • Estimation of the hydrodynamic radius of ion alginate. - Abstract: Taylor dispersion technique was used for measuring mutual diffusion coefficients of sodium alginate aqueous solutions at T = 298.15 K, by using as carrier stream solution both pure water and solutions of this polyelectrolyte at a slightly different concentration. The limiting values found at infinitesimal ionic strength, D0, were determined by extrapolating to c → 0. These studies were complemented by molecular mechanics calculations. From the experimental data, it was possible to estimate both the limiting conductivity and the tracer diffusion coefficient values for the alginate anion, and the hydrodynamic radius of the sodium alginate (NaC6H7O6), as well as to discuss the influence of the kinetic, thermodynamic and viscosity factors on the diffusion of sodium alginate in aqueous solutions at finite concentrations. Thus, the aim of our innovative research is to contribute to a better understanding of the structure and the thermodynamic behavior of these polymeric systems in solution and supplying the scientific and technological communities with data on these important parameters in solution transport processes

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

    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.

  6. Is bicarbonate buffer suitable as a dissolution medium?

    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

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

    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

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

    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.

  9. Radiolysis of sodium nitrate concentrated solutions in D2O

    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

  10. The interaction of long chain sodium carboxylates and sodium dodecylsulfate with lead(II) ions in aqueous solutions.

    Pereira, Rui F P; Valente, Artur J M; Burrows, Hugh D

    2014-01-15

    The interaction of sodium octanoate, decanoate or dodecanoate with lead(II) has been studied in aqueous solutions using potentiometry, electrical conductivity, turbidity and ICP-OES measurements. These show an alkyl chain length dependence on the behavior. At the lead(II) concentration used (1.0 mM), relatively strong interactions are observed with the decanoate and dodecanaote, leading to formation of the lead carboxylates (soaps) as insoluble complexes. All techniques show 1:2 (metal:carboxylate) stoichiometry corresponding to charge neutralization. With sodium octanoate and lead(II), a rather weaker interaction is seen, and complexation is only observed at metal:carboxylate ratios > 0.5. However, in contrast to our previous work on octanoate and calcium(II) in aqueous solutions [1], precipitation does occur at higher concentrations. This difference between the behavior of the metal ions is probably due to the more covalent nature of the bonds of the carboxylate with Pb(2+) than with Ca(2+). Association constants of the complexes have been determined from potentiometric measurements and are consistent with data on solubility products. A comparison is made of the effect of surfactant head group on the interactions with lead(II) using two surfactants with the same chain length: dodecanoate and dodecylsulfate. Differences in their interactions with this metal ion in aqueous solutions are interpreted in terms of greater covalency of the bond between the metal and the carboxylate than with the sulfate group. PMID:24231086

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

    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)

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

    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)

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

    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

  14. 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

    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.

  15. 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

    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.

  16. Practical considerations for bicarbonate loading and sports performance.

    Burke, Louise M

    2013-01-01

    Consumption of sodium bicarbonate (300 mg/kg 1-2 h before exercise) can temporarily increase blood bicarbonate concentrations, enhancing extracellular buffering of hydrogen ions which accumulate and efflux from the working muscle. Such 'bicarbonate loading' provides an ergogenic strategy for sporting events involving high rates of anaerobic glycolysis which are otherwise limited by the body's capacity to manage the progressive increase in intracellular acidity. Studies show that bicarbonate loading strategies have a moderate positive effect on the performance of sports involving 1-7 min of sustained strenuous exercise, and may also be useful for prolonged sports involving intermittent or sustained periods of high-intensity work rates. This potential to enhance sports performance requires further investigation using appropriate research design, but may be limited by practical considerations such as gut discomfort or the logistics of the event. The effect of chronic use of bicarbonate supplementation prior to high-intensity workouts to promote better training performance and adaptations is worthy of further investigation. While this relatively simple dietary strategy has been studied and used by sports people for over 80 years, it is likely that there are still ways in which further benefits from bicarbonate supplementation can be developed and individualized for specific athletes or specific events. PMID:23765347

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

    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

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

    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

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

    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)

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

    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.

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

    Khong, Thang Trung; Aachmann, Finn L; Vrum, 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

  2. Antimicrobial action of sodium hypochlorite and castor oil solutions for denture cleaning – in vitro evaluation

    Marcela Moreira SALLES

    2015-01-01

    Full Text Available The objective of this in vitro study was to evaluate the antimicrobial action of sodium hypochlorite (0.25% and 0.50% and 10% castor oil solutions against specific microorganisms, by counting Colony Forming Units (CFU of clinically important bacteria and Candida species. Acrylic resin specimens (n = 320; Lucitone 550 were obtained from square metal matrices (10 x 10 x 2 mm, sterilized by microwave (650W, for 6 minutes and contaminated by Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Bacillus subtilis, Escherichia coli, Streptococcus mutans, Enterococcus faecalisand Candida glabrata. The specimens were immersed for 20 minutes in one of the following hygiene solutions (n = 10/each: A – 0.25% Sodium hypochlorite; B – 0.5% Sodium hypochlorite; C – 10% Castor oil solution; and D (Control – saline. Adhered cells were suspended and inoculated into a selective solid medium (37ºC for 24 h. The Student’s t-test (α = 0.05 was performed to compare log10(CFU+1/mL between Groups C and D. The results showed that sodium hypochlorite (0.25% and 0.5% completely eliminated all detectable microorganisms. The castor oil solution eliminatedB. subtilisand reduced counts for other strains. Differences between C and D were significant (p E. faecalis. Both sodium hypochlorite solutions (0.25% and 0.5% were effective in eliminating all microorganisms evaluated, and may be useful as cleaning solutions for complete dentures. The castor oil solution provided moderate efficacy and performed differently on the tested species, with the strongest effect on B. subtilis and with non-significant action on E. faecalis.

  3. Bicarbonate kinetics in Indian males

    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.

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

    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 H₂O 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 BH₄⁻ 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 BH₄⁻, 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

  5. 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?

    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.

  6. Pulse radiolysis of aqueous solutions of sodium tetraphenylborate

    In previous work on the 60Co γ-radiolysis of aqueous tetraphenylborate (TPB-) solutions carried out in this laboratory, it was found that several organic products, including benzene, phenol and biphenyl, are produced with substantial yield. However, the reaction mechanism was not established. In the present study, reactions initiated by OH· radicals, N3· radicals and e-aq in aqueous TPB- solutions were studied by pulse radiolysis using a 600 keV Febetron electron accelerator. The lack of reactivity between TPB- and e-aq was demonstrated by directly monitoring the transient optical absorbance of e-aq. Concerning the reaction with OH·, two schemes were considered: (1) electron transfer from B(C6H5)4- to OH·; or (2) OH· addition to B(C6H5)4-. Comparison of observed transient absorption spectra with expectations based on the two different schemes suggests that OH· addition is the dominant reaction pathway under conditions of N2O saturation, with an experimentally determined second-order rate constant of 6.2 x 109 M-1 s-1. A mechanism based on an initial first-order self-decomposition of the OH· adduct, (C6H5)3BC6H5OH·-, with measured rate constant of 4 x 104s-1 is proposed. Kinetic modeling on the proposed mechanistic scheme gives good agreement with our experimental results. (author)

  7. Thermal diffusion processes in aqueous sodium chloride solutions

    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

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

    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.

  9. Electrochemical performance of vanadium in sodium chloride solution

    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.)

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

    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.

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

    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

  12. The determination of hydroxide and carbonate in concentrated sodium chloride solutions

    Roolvink, W.B.; Bos, M.

    1980-01-01

    A computer method for the determination of carbonate and hydroxide in concentrated (2.89 M) sodium chloride solutions is described. The method is based on multiparametric curve-fitting and can also be applied to salts of dibasic acids with unknown equilibrium constants. The systematic error is not more than 1%. The titration and calculation takes less than 20 min.

  13. Concentration of rhenium from dilute sodium chloride solutions

    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.

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

    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.

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

    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.

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

    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)

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

    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 7C. 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

    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

    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. Thermogravimetric analysis of phase transitions in cement compositions mixed by sodium silicate solution

    Fedosov Sergey Viktorovich

    2014-01-01

    Full Text Available This paper presents a study of the capability to modify cement by mechanical activation of sodium silicate water solution. Admixtures or blends of binding agents were employed for modifying concrete properties. The liquid glass is applied to protect from chemically or physically unfavorable environmental impacts, such as acidic medium and high temperature. The sodium silicate is a high-capacity setting accelerator. The increasing of the liquid glass proportion in the mix leads to the degradation of the cement paste plasticity and for this reason it is necessary to reduce the amount of liquid glass in the cement paste. The activation of dilute water solution of sodium silicate into rotary pulsating apparatus directly before tempering of the cement paste is an effective way to decrease mass fraction of liquid glass in the cement paste. The results of the combined influence of liquid glass and mechanical activation on physicochemical processes taking place in cement stone are represented in this research. Thermogravimetric analysis was used in order to study cement blends. Thermogravimetric analysis of modified cement stone assays was performed by thermo analyzer SETARAM TGA 92-24. The results of the analysis of phase transition taking place under high-temperature heating of cement stone modified by the mechanical activation of the water solution of the sodium silicate were introduced. Thermograms of cement stone assays were obtained at different hardening age. The comparison of these thermograms allows us to come to a conclusion on the formation and the retention during long time of a more dense structure of the composite matrix mixed by the mechanical activation of sodium silicate water solution. The relation between the concrete composition and its strength properties was stated. Perhaps, the capability of modified concrete to keep calcium ions in sparingly soluble hydrosilicates leads to the increase in its durability and corrosion resistance.

  1. CONTROL OF GRAPEVINE LEAF SPOT CAUSED BY PSEUDOCERCOSPORA VITIS WITH APPLICATION OF BICARBONATE

    Seok-Hee Park

    2014-12-01

    Full Text Available This study was conducted to find environmentally friendly control methods and to investigate occurrence pattern of grapevine leaf spot, major disease in ‘Campbell early’ cultivar. Grapevine leaf spot caused by Pseudocercospora vitis is one of the most important disease in Korea. The occurrence pattern of leaf spot for ‘Campbell early’ cultivar was conducted in organic vineyards and conventional vineyards of Sangju, the main growing region of grape from 2012 to 2013. As results, the symptom of leaf spot was observed at last-June firstly in the organic vineyards and then the occurrence rate was gradually increased. The rate of lesion area was rapidly increased to 80.2% in last-August. To control grapevine leaf spot, some materials were tested and bicarbonate was selected. The optimum concentration of bicarbonates for control of grapevine leaf spot is 0.5%, and occurrence of grapevine leaf spot by treatment of 0.5% sodium bicarbonate and ammonium bicarbonate were 6.2 or 8.2%, respectively. This result showed that bicarbonate was more effective than Lime Bordeaux mixture in control of grapevine leaf spot widely used in grape organic cultivation for disease control. But phytotoxicity was observed in the treatment of 1% sodium bicarbonate and 2% potassium bicarbonate. So, it is expected that grapevine leaf spot will be successfully controlled by application of 0.5% bicarbonate.

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

    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...

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

    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

  4. Synergistic hydrogen generation from aluminum, aluminum alloys and sodium borohydride in aqueous solutions

    Soler, Lluis; Macanas, Jorge; Munoz, Maria [Centre Grup de Tecniques de Separacio en Quimica (GTS), Unitat de Quimica Analitica, Departament de Quimica, Universitat Autonoma de Barcelona, Campus UAB, s/n, 08193 Bellaterra, Barcelona, Catalonia (Spain); Casado, Juan [MATGAS R and D Centre, Campus de la UAB 08193 Bellaterra, Barcelona (Spain)

    2007-12-15

    A new method to produce high purity hydrogen using reactions of aluminum and sodium borohydride with aqueous alkaline solutions is described. This process mainly consumes water and aluminum (or its alloys) which are cheaper raw materials than the borohydride. As a consequence, this process could be competitive for in situ production of hydrogen. Moreover, a synergistic effect has been observed in hydrogen production rates and yields combining aluminum or aluminum alloys with sodium borohydride in aqueous solutions. Good results have been obtained for powders of Al, Al/Si and Al/Co alloys. The development of this idea could improve yields and reduce costs in power units based on fuel cells which use borohydride as raw material for hydrogen production. (author)

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

    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.

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

    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 < 1.4 mol/kg water are measured at 293.15, 298.15, 308.15, and 318.5 K using an isoperibolic calorimeter. The heat capacity of NaIBP in the temperature range of 273.15-528.15 K is measured using a DSC 204 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.

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

    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.

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

    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

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

    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.

  10. An Impedance Investigation of the Mechanism of Pure Magnesium Corrosion in Sodium Sulfate Solutions

    Baril, Geneviève; Galicia, Gonzalo; Deslouis, Claude; Pébère, Nadine; Tribollet, Bernard; Vivier, Vincent

    2007-01-01

    The corrosion behavior of pure magnesium in sodium sulfate solutions was investigated using voltammetry and electrochemical impedance spectroscopy with a rotating disk electrode. The analysis of impedance data obtained at the corrosion potential was consistent with the hypothesis that Mg corrosion is controlled by the presence of a very thin oxide film, probably MgO, and that the dissolution occurs at film-free spots only. This hypothesis was substantiated both by the superposition of the EIS...

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

    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.

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

    Maksim Y. Khotimchenko; Elena A. Podkorytova; Valeri V. Kovalev; 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...

  13. The hydration of interstitial Portland cement phases in sodium hydroxide and magnesium sulfate solutions

    Clark, Boyd Arthur

    Formation of sulfoaluminate compounds was investigated by isothermal calorimetry and X-ray diffraction (XRD). Tricalcium aluminate/gypsum mixtures with a molar ratio of 1:1 sulfate-to-aluminate were hydrated at constant temperatures from 30 to 90°C; in de-ionized water, in 200mM and in 500mM sodium hydroxide (NaOH) solutions. Hydration in de-ionized water produced ettringite and monosulfate as the dominant crystalline phases, regardless of temperature. Complex assemblages of phases formed in 200mM and 500mM sodium hydroxide including ettringite, monosulfate and U-phase, at all temperatures. Hydration of monosulfate and gypsum was also carried out at constant temperatures from 30° to 80°C using de-ionized water and 0.2M, 0.5M, and 1.0M sodium hydroxide (NaOH) solutions. Ettringite was found to be the dominant crystalline phase over the entire temperature range and at all sodium hydroxide concentrations. A sodium-substituted monosulfate phase was formed as a hydration product in the 1.0M sodium hydroxide solution regardless of temperature. Sulfoaluminate compounds formed by tricalcium aluminate hydration in magnesium sulfate solution were investigated by isothermal calorimetry, XRD, and scanning electron microscopy (SEM). Hydration was carried out in 0.5, 1.0 and 3.0M magnesium sulfate solutions and isothermally at temperatures from 30 to 80°C. Monosulfate, ettringite, gypsum and a hydrogarnet phase (Ca3Al2O6·6H2O) were all observed as hydration products. Monosulfate and hydrogarnet were the only phases observed for hydration in 0.5 and 1.0M magnesium sulfate solutions. Ettringite was the dominant crystalline phase after hydration in 3.0M solution, regardless of temperature. To investigate the rate of hydration, reactions at 60°C in 3.0M magnesium sulfate solution were quenched after 26 minutes, 73 minutes, 2.5 hours and 12 hours to establish the evolution of hydrated phases. Depending on hydration times ettringite, monosulfate, gypsum, hydrogarnet and residual tricalcium aluminate were observed. No crystalline magnesium-rich phases were detected by XRD. The products formed by hydration of tetracalcium aluminoferrite (Ca 2AlFeO5) and magnesium sulfate solutions were investigated by isothermal calorimetry, XRD and SEM analyses. Hydration reactions were carried out isothermally at temperatures from 25 to 80°C in 0.25M, 0.5M, 1.0M, 2.0M, and 3.0M magnesium sulfate solutions. Gypsum was the initial hydration product in all magnesium sulfate concentrations and was the only crystalline hydration product in 2.0M and 3.0M magnesium sulfate solutions. Monosulfate was the dominant crystalline phase produced over the entire temperature range when hydration was carried out in magnesium sulfate concentrations between 0.25M and 1.0M. No crystalline phases incorporating iron were observed regardless of magnesium sulfate concentration or temperature. Hydration in 1.0M MgSO 4 solution was more extensively investigated at 50°C. SEM observations indicated gypsum formed initially, consisting of fine particles (ettringite, and monosulfate were present at intermediate times. Monosulfate was the final crystalline hydration product. Amorphous solids produced include a calcium/iron-rich gel and a magnesium/aluminum/sulfate-rich phase. The calcium/iron-rich gel is the only iron-rich phase observed in the hydrated phase assemblage.

  14. Sodium Tetraethylenepentamine Heptaacetate as Novel Draw Solute for Forward Osmosis—Synthesis, Application and Recovery

    Qing Wu Long

    2015-11-01

    Full Text Available Osmotic energy, as a sustainable energy source with little environmental impact, has drawn much attention in both academia and industry in recent years. Osmotically driven membrane processes can harvest the osmotic energy and thus have great potential to produce sustainable clean water or electric energy. The draw solution, as an osmotic component, has been more and more explored by scientists in recent years in order to achieve a high osmotic pressure and suitable molecular size. In this work, a novel draw solute—sodium tetraethylenepentamine heptaacetate (STPH—is synthesized and identified by nuclear magnetic resonance spectroscopy (1H-NMR and Fourier transform infrared (FTIR. Its solution properties are optimized in terms of the solution pH and concentration, and related to the forward osmosis (FO performance. A water flux of 28.57 LMH and a low solute flux of 0.45 gMH can be generated with 0.5 g/mL STPH draw solution and de-ionized water (DI water as the feed solution under pressure retarded osmosis (PRO mode, which is superior to the FO performance with many other draw solutes reported. Further FO desalination test shows a stable water flux of 9.7 LMH with 0.3 g/mL STPH draw solution and 0.6 M NaCl feed solution. In addition, the draw solution recovery is also investigated.

  15. In-Situ Method for Treating Residual Sodium

    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.

  16. Deuterium kinetic isotope effect for oxidation of perdeuterated sodium butyrate with manganate in 3 M sodium hydrochloride solution

    Deuterium kinetic effect, D-KIE, for oxidation of perdeuterided sodium butyrate, CD3(CD2)2COONa, with manganate in the aqueous solution of 3M NaOH has been determined in the temperature range 323-373 K. The temperature dependent kH/kD ratios are in the range from 17.59 at 323 K to 11,25 at 373 K. The activation energy difference, δQ0 = Q0DD - Q0=HH δH0DD - δH0HH = 9.20 kJ mol-1, and the Arrhenius preexponential factors ratio A0DD/A0HH is equal to 1.76, corresponding to δS0DD - δS0HH = 4.70 k J-1 as deduced from the Arrhenius and Eyring diagrams. This is the main evidence of tunnelling in the transfer of methylene hydrogens of butyrate to the negatively charged oxygens of manganate in very basic solutions. The k0HH/k0DD ratios, corrected for the ionic strength, have been reproduced by multiplying the (k0HH/k0DD)KIE value, caused by zero point energy differences, by the Bell tunnel correction QtHH.QtDD. The half width of the energy barrier, as approximated by an inverted parabola, was found to be equal to 5x10-11 m. The physico-chemical origin of the energy barrier for the oxidation of n-chain aliphatic carboxylates with MnO42- ions in strongly alkaline solutions has been discussed. The mechanisms of the permanganate versus manganate oxidation i. e., in acidic versus alkaline media are compared. (author)

  17. 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

    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...

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

    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

  19. Bicarbonate attenuates arterial desaturation during maximal exercise in humans

    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 varia...... attenuated acidosis and in turn arterial desaturation during maximal exercise....

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

    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

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

    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

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

    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

  3. 21 CFR 184.1733 - Sodium benzoate.

    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. Effect of Anionic Surfactant on the Thermo Acoustical Properties of Sodium Dodecyl Sulphate in Polyvinyl Alcohol Solution by Ultrasonic Method

    Ravichandran, S; C. Rathika Thaya Kumari

    2011-01-01

    The interaction of sodium dodecyl sulphate (SDS) / poly(vinyl alcohol) (PVA) solution was studied by ultrasonic velocity measurements. Ultrasonic velocity, density, viscosity in mixtures of sodium dodecyl sulphate in polyvinyl alcohol was measured over the entire range of composition. From the experimental data, other related thermodynamic parameters, viz., adiabatic compressibility, intermolecular free length, surface tension, relative association, relaxation time, absorption coefficient and...

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

    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.

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

    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

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

    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

  8. Derivatization of organometal(loid) species by sodium borohydride problems and solutions.

    Grüter, U M; Hitzke, M; Kresimon, J; Hirner, A V

    2001-12-14

    Like other derivatization techniques, hydride generation is a chemical reaction that produces side-reactions leading to analytical problems. Demethylation of dimethylarsinic acid was observed to be dependent upon the pH level of the hydride generation reaction mixture. If the reaction mixture was acidic, then in addition to (CH3)2AsH, the monomethyl arsenic hydride [(CH3)AsH2] could be detected. Demethylation and also the formation of an unidentified arsenic species were noted when trimethyl arsonic oxide was used as derivatization educt. All of these effects depend on the pH level of the hydride generation mixture. We observed significant levels of organometal(loid) species of elements such as Ge, As, Sn, Sb, Hg and Bi in blank hydride generation mixtures. The organometal(loid) contamination was irreproducible even during I day using a single solution of sodium borohydride in deionized water. We concluded that the organometal(loid) contamination arises directly from the derivatization agent, sodium borohydride, itself. Use of helium purging and various adsorptive materials to decontaminate the sodium borohydride solution prior to analysis did not result in a significant decrease in organometal(loid) contamination levels. Use of a palladium-cluster stabilised with 1,10-phenanthrolin as alternative hydride generation derivatization agent was not found to be suitable, since reaction yields were poor and transmethylation reactions were noted. PMID:11771841

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

    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.

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

    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.

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

    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.

  12. In situ generation of hydrogen from water by aluminum corrosion in solutions of sodium aluminate

    Soler, Lluis; Candela, Angelica Maria; Munoz, Maria; Casado, Juan [Centre Grup de Tecniques de Separacio en Quimica (GTS), Unitat de Quimica Analitica, Departament de Quimica, Universitat Autonoma de Barcelona, Campus UAB s/n, 08193 Bellaterra, Barcelona, Catalonia (Spain); Macanas, Jorge [Laboratoire de Genie Chimique, UMR 5503 CNRS-INPT-UPS, Universite de Toulouse, Toulouse (France)

    2009-07-01

    A new process to obtain hydrogen from water using aluminum in sodium aluminate solutions is described and compared with results obtained in aqueous sodium hydroxide. This process consumes only water and aluminum, which are raw materials much cheaper than other compounds used for in situ hydrogen generation, such as hydrocarbons and chemical hydrides, respectively. As a consequence, our process could be an economically feasible alternative for hydrogen to supply fuel cells. Results showed an improvement of the maximum rates and yields of hydrogen production when NaAlO{sub 2} was used instead of NaOH in aqueous solutions. Yields of 100% have been reached using NaAlO{sub 2} concentrations higher than 0.65 M and first order kinetics at concentrations below 0.75 M has been confirmed. Two different heterogeneous kinetic models are verified for NaAlO{sub 2} aqueous solutions. The activation energy (E{sub a}) of the process with NaAlO{sub 2} is 71 kJ mol{sup -1}, confirming a control by a chemical step. A mechanism unifying the behavior of Al corrosion in NaOH and NaAlO{sub 2} solutions is presented. The application of this process could reduce costs in power sources based on fuel cells that nowadays use hydrides as raw material for hydrogen production. (author)

  13. 2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

    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.

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

    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

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

    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.

  16. 21 CFR 582.1135 - Ammonium bicarbonate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium bicarbonate. 582.1135 Section 582.1135 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1135 Ammonium bicarbonate. (a) Product. Ammonium bicarbonate. (b) Conditions of use....

  17. Hydrogen generation utilizing alkaline sodium borohydride solution and supported cobalt catalyst

    Ye, Wei; Ma, Li [Lab. of PEMFC Key Materials and Technologies, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Huamin; Xu, Dongyan; Yi, Baolian [Lab. of PEMFC Key Materials and Technologies, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2007-02-10

    Supported Co catalysts with different supports were prepared for hydrogen generation (HG) from catalytic hydrolysis of alkaline sodium borohydride solution. As a result, we found that a {gamma}-Al{sub 2}O{sub 3} supported Co catalyst was very effective because of its special structure. A maximum HG rate of 220 mL min{sup -1} g{sup -1} catalyst and approximately 100% efficiency at 303 K were achieved using a Co/{gamma}-Al{sub 2}O{sub 3} catalyst containing 9 wt.% Co. The catalyst has quick response and good durability to the hydrolysis of alkaline NaBH{sub 4} solution. It is feasible to use this catalyst in hydrogen generators with stabilized NaBH{sub 4} solutions to provide on-site hydrogen with desired rate for mobile applications, such as proton exchange membrane fuel cell (PEMFC) systems. (author)

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

    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, ΔHa and ΔSa) 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

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

    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)

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

    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.

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

    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.)

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

    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)

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

    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.

  4. Diffusion coefficients of β-cyclodextrin sulfated sodium salt in aqueous solutions

    Graphical abstract: Structure of β-cyclodextrin sulfated sodium salt. - Highlights: • Mutual diffusion coefficients of β-cyclodextrin sulfated sodium salt (NaSO3βCD) in aqueous solutions were measured. • Influence of the viscosity, thermodynamic and temperature factors on the variation of diffusion was analysed. • Estimation of the hydrodynamic radius of NaSO3βCD was obtained. - Abstract: The Taylor dispersion technique has been used for measuring mutual diffusion coefficients of β-cyclodextrin sulfated sodium salt (NaSO3βCD) at temperatures (298.15 and 310.15) K and at finite concentrations. These studies have been complemented by density and viscosity measurements. From these experimental results, the hydrodynamic radius Rh, and its dependence on the viscosity, diffusion coefficient at infinitesimal concentration, D0, ion conductivity of NaSO3βCD and the thermodynamic factor, FT, have been estimated, permitting us to have a better understanding of the structure of the aqueous system containing NaSO3βCD

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

    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

  6. Controle da pinta-preta em tomateiro e da mancha-zonada em pepino por meio de bicarbonato de sódio e óleo vegetal Control of early blight on tomato and net spot on cucumber through application of sodium bicarbonate and vegetal oil

    Juan Roberto Ramírez-Otárola Sarmiento

    1999-07-01

    Full Text Available Foram realizados dois ensaios, em condições de campo, na UNESP/ FCAV, Jaboticabal (SP. O primeiro (maio a outubro de 1993 teve como objetivo avaliar a eficiência de pulverizações semanais de bicarbonato de sódio (10 g/l, óleo vegetal 'Natur'l óleo (10 ml/l e iprodione (0,75 g/l, aplicados isoladamente ou em combinação dois a dois, no controle da pinta-preta (Alternaria solani em tomateiro, cultivar Jumbo AG-592. No segundo ensaio (março a junho de 1993, o objetivo foi determinar a eficiência de pulverizações semanais em diferentes doses de bicarbonato de sódio (5, 10 e 15 g/l comparadas ao benomil (0,5 g/l, no controle da mancha-zonada (Leandria momordicae em pepino híbrido 'Premier'. Utilizou-se o delineamento experimental de blocos ao acaso com quatro repetições para ambos os experimentos. Foram utilizadas parcelas de 40 plantas distribuídas em 4 fileiras de 5,0 e 2,5 m de comprimento para os experimentos com pepino e tomate, respectivamente. As avaliações da severidade da doença foram feitas a cada quatorze dias (as cinco primeiras e a cada sete dias (as duas últimas e foram iniciadas 39 dias após o transplante do tomate. Para o pepino, foram realizadas cinco avaliações, iniciadas 28 dias após o transplante e repetidas a cada quatorze dias. Foram determinadas as curvas de progresso das doenças e a produtividade dentro de cada tratamento para cada cultura. Pela observação dos valores dos coeficientes de determinação das diferentes curvas epidemiológicas, concluiu-se que a quinta folha e a transformação logística se mostraram mais adequadas para o estudo epidemiológico da pinta-preta do tomateiro, enquanto a quarta folha e a transformação logística se mostraram mais adequadas para o estudo epidemiológico da mancha-zonada. Constatou-se o efeito positivo do iprodione no controle de pinta-preta, isolado ou quando misturado ao bicarbonato de sódio ou ao óleo vegetal, não havendo diferença estatística significativa entre iprodione e bicarbonato de sódio. Para a mancha-zonada o tratamento com benomil diminuiu a taxa de desenvolvimento da doença, enquanto que o bicarbonato de sódio não teve efeito. Os resultados obtidos no presente trabalho sugerem que o bicarbonato de sódio e óleo vegetal são substâncias que apresentam potencial para o controle da pinta-preta e mancha-zonada, necessitando porém, de novos estudos.Two experiments were carried out under field conditions at UNESP/FCAV, Jaboticabal, São Paulo state, Brazil. In the first experiment (from May to October, 1993 the efficiency of weekly sprays of sodium bicarbonate (1%, vegetal oil (1% and iprodione (0.075%, alone or in combination, were studied for the control of tomato early blight (Alternaria solani, using tomato cv. Jumbo AG-592. In the second experiment (March to June, 1993 the efficiency of weekly sprays of different doses of sodium bicarbonate (0.5, 1 and 1.5% were compared with benomyl (0.05%, on the control of cucumber net spot (Leandria momordicae, using cucumber cv. Premier. The experiments followed a randomised block design with four replications and forty plants distributed in four rows of 5.0 and 2.5 m long used respectively for cucumber and tomato. Disease severity on tomate was rated at 14 day intervals (the first five and at 7 day intervals (the last two, beginning 39 days after transplanting. Disease severity for cucumber net spot was rated five times, at 14 day intervals, beginning 28 days after transplanting. Disease progress curves for each treatment for each culture were determined. Fruit yield for each culture was also evaluated. Results showed that evaluation of disease severity in the fifth leaf and logistic transformation were most suitable for the study of tomato early blight epidemics. For cucumber net spot, evaluation in the fourth leaf and logistic transformation were the most suitable, as shown by the determination coefficient values. Both iprodione and sodium bicarbonate provided efficient early blight control, with no statistical differences between them. For cucumber net spot, the fungicide benomyl decreased the infection rate of the epidemic whilst sodium bicarbonate had no effect. The results indicate that sodium bicarbonate and vegetal oil have a potential for early blight and net spot control, although further studies are required.

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

    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.)

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

    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

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

    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

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

    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.)

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

    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

  12. The Chemical Etching of Fission Tracks in the Thin Polycarbonate Film using Sodium Hydroxide Solution

    The thin 15 μm Polycarbonate film was irradiated by fission fragments of uranium-235 in thermal column tube at the TRR-1/M1 (Thai Research Reactor-1/Modification 1) for 30 seconds that producing the latent tracks on the PC film. Tracks in the irradiated film was etched in the chemical etchant by sodium hydroxide (NaOH) solution in the condition of 6N at 70oC for 30, 60 90 and 120 minutes. Track diameters are 1.14, 3.73, 4.02 and 4.62 micron respectively when etched in 6N sodium hydroxide solution at 70oC for 30, 60, 90 and 120 minutes. At pressure 111.11 kPa, the flow rate of water are 1.9x10-4, 1.12 x 10-4 and 2.39 x 10-4 L/min.cm-2 at 60, 90 and 120 minutes, respectively. Water cannot penetrate for 30 minutes etching time

  13. Feasibility study of hydrogen generation from sodium borohydride solution for micro fuel cell applications

    Xia, Z. T.; Chan, S. H.

    This paper presents work on hydrogen generation from sodium borohydride (NaBH 4) solution that could have great application in micro fuel cells. A hydrogen test method has been developed, which is very effective for sustained measurement of the generation rate and yield of hydrogen. The hydrogen is supplied to a proton exchange membrane fuel cell. The discharged current is measured by a computer-controlled electronic load system connecting to the fuel cell where hydrogen generation rate and yield are calculated. The study is focused on the slow release of hydrogen. The results show that if the concentration of NaBH 4 solution is 10%, no solid substance is formed and the catalyst supported on the ion-exchange resin beads remains unchanged. The hydrogen generation can be controlled by inserting or removing the catalyst into/from the solution, which can be applied to a micro fuel cell. When the concentration of NaBH 4 solution is 20%, however, the catalyst beads are broken up and dispersed in the solution (probably by the NaBO 2 crystallization force) and give rise to uncontrollable generation of hydrogen.

  14. Feasibility study of hydrogen generation from sodium borohydride solution for micro fuel cell applications

    Xia, Z.T.; Chan, S.H. [Fuel Cell Strategic Research Programme, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2005-12-01

    This paper presents work on hydrogen generation from sodium borohydride (NaBH{sub 4}) solution that could have great application in micro fuel cells. A hydrogen test method has been developed, which is very effective for sustained measurement of the generation rate and yield of hydrogen. The hydrogen is supplied to a proton exchange membrane fuel cell. The discharged current is measured by a computer-controlled electronic load system connecting to the fuel cell where hydrogen generation rate and yield are calculated. The study is focused on the slow release of hydrogen. The results show that if the concentration of NaBH{sub 4} solution is 10%, no solid substance is formed and the catalyst supported on the ion-exchange resin beads remains unchanged. The hydrogen generation can be controlled by inserting or removing the catalyst into/from the solution, which can be applied to a micro fuel cell. When the concentration of NaBH{sub 4} solution is 20%, however, the catalyst beads are broken up and dispersed in the solution (probably by the NaBO{sub 2} crystallization force) and give rise to uncontrollable generation of hydrogen. (author)

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

    Šaletić 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.

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

    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

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

    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.

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

    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…

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

    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

  20. Formation of fine solid particles from aqueous solutions of sodium chloropalladate by gamma-ray irradiation

    Studies have been carried out on the radiation chemical formation of palladium fine particles in argon saturated aqueous solutions of sodium chloropalladate without organic stabilizer. The solutions were irradiated with gamma-rays from a cobalt gamma-ray source and the irradiated solutions were subjected to the dynamic light scattering analysis for the particle diameter measurements, and to the UV-visible optical absorption spectroscopy for the measurements of turbidity (absorption at 700 nm) and remaining chloropalladate ion concentrations in the solution. In the solution of pH = 1.95 by HCl, the turbidity increased after the irradiation and then decreased with time. The concentration of remaining palladate ion in the solution decreased by the irradiation, but it gradually increased with time after the irradiation. These phenomena were qualitatively explained by the reaction scheme in that a precursor to the solid particles still exists in the solution after the irradiation was terminated, and that intermediates including the precursor reacted with chloride ion to re-form chloropalladate ions. The average diameter of the particles after the irradiation was ca. 20 nm and it increased with time to 40 nm at 2.75 kGy, and to 80 nm at 8.25 kGy absorption of radiation. The solution of pH = 0.65 by HCl was found to give lower yields of particles than those observed for the solution of pH = 1.95, and to give the particles of diameters about 150-200 nm. In the solution containing HClO4 instead of HCl, palladium particles were also formed by the irradiation, whereas no backward reaction after the irradiation was observed due to the low concentration of chloride ion in the solution. The average diameter of the particles after the irradiation was about 300 nm and increased with time after the irradiation to a final values which was found to depend on pH of the solution and dose. (author)

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

    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.

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

    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.

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

    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

  4. On the storage of the sodium borohydride solution used in the hydride-generation atomic-absorption technique.

    Bye, R

    1982-09-01

    A critical examination has been made of the stability of sodium borohydride solutions on storage at room temperature and at 4 degrees in a refrigerator, by comparison of the reductive power for selenium(IV) in a hydride-generator, with that of a freshly prepared solution. No significant change in reactivity appeared to be caused by storage for a period of three weeks, and there seems no need to use freshly prepared solutions for analytical work. PMID:18963239

  5. 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.

    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

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

    Briot, Thomas; Vrignaud, Sandy; Lagarce, Frdric

    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

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

    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

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

    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)

  10. Adsorption of U(VI) ions from low concentration uranium solution by thermally activated sodium feldspar

    The thermally activated sodium feldspar (TASF), a novel material, was prepared by calcinating the micron sodium feldspar (SF) at 450 deg C for 45 min. The TASF and the SF were characterized using X-ray diffraction and mercury injection porosimetry, and the TASF was found to have larger specific surface area and larger porosity than SF. The effects of the initial pH, temperature, contact time and initial U(VI) ions concentration on the adsorption of U(VI) ions from the low concentration uranium solution by TASF were investigated. The maximum adsorption efficiency of TASF for 0.5 mg/L uranium solution amounted to 95.49 % when the initial pH was 5.0, the temperature, 318 K, and and the contact time, 600 min. The relationship between the adsorption capacity qe and equilibrium concentration Ce can well be described by Freundlich equation. Adsorption isotherm and the analysis by FT-IR coupled with SEM revealed that U(VI) ions were adsorbed onto the surface of TASF in multimolecular or cluster states, and that the intraparticle diffusion occurred in spontaneous process. The basic thermodynamic parameters including free energy change, entropy change and enthalpy change were calculated to comprehend the intrinsic features and spontaneous nature of the adsorption process. The FT-IR spectroscopic characterization for the TASF indicated that many groups were involved in the adsorption process of U(VI) ions, and the -OH group played a more important role. The experimental results suggested that TASF had great adsorption efficiency and strong potentiality of enrichment and recovery for the low concentration U(VI). (author)

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

    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.

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

    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. Dissolution kinetics of UO2: Flow-through tests on UO2.00 pellets and polycrystalline schoepite samples in oxygenated, carbonate/bicarbonate buffer solutions at 25 degree C

    The modelling of radionuclide release from waste forms is an important part of the performance assessment of a potential, high-level radioactive waste repository. Since spent fuel consists of UO2 containing actinide elements and other fission products, it is necessary to determine the principal parameters affecting UO2 dissolution and quantify their effects on the dissolution rate before any prediction of long term release rates of radionuclides from the spent fuel can be made. As part of a complex matrix to determine the dissolution kinetics of UO2 as a function of time, pH, carbonate/bicarbonate concentration and oxygen activity, we have measured the dissolution rates at 25 degrees C of: (1) UO2 pellets; (2) UO2.00 powder and (3) synthetic dehydrated schoepite, UO3.H2O using a single-pass flow through system in an argon-atmosphere glove box. Carbonate, carbonate/bicarbonate, and bicarbonate buffers with concentrations ranging from 0.0002 M to 0.02 M and pH values form 8 to 11 have been used. Argon gas mixtures containing oxygen (from 0.002 to 0.2 atm) and carbon dioxide (from 0 to 0.011 atm) were bubbled through the buffers to stabilize their pH values. 12 refs., 2 tabs

  14. Hydrogen generation from sodium borohydride solution using a ruthenium supported on graphite catalyst

    Liang, Yan; Dai, Hong-Bin; Ma, Lai-Peng; Wang, Ping; Cheng, Hui-Ming [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2010-04-15

    The catalyst with high activity and durability plays a crucial role in the hydrogen generation systems for the portable fuel cell generators. In the present study, a ruthenium supported on graphite catalyst (Ru/G) for hydrogen generation from sodium borohydride (NaBH{sub 4}) solution is prepared by a modified impregnation method. This is done by surface pretreatment with NH{sub 2} functionalization via silanization, followed by adsorption of Ru (III) ion onto the surface, and then reduced by a reducing agent. The obtained catalyst is characterized by transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). Very uniform Ru nanoparticles with sizes of about 10 nm are chemically bonded on the graphite surface. The hydrolysis kinetics measurements show that the concentrations of NaBH{sub 4} and NaOH all exert considerable influence on the catalytic activity of Ru/G catalyst towards the hydrolysis reaction of NaBH{sub 4}. A hydrogen generation rate of 32.3 L min{sup -1} g{sup -1} (Ru) in a 10 wt.% NaBH{sub 4} + 5 wt.% NaOH solution has been achieved, which is comparable to other noble catalysts that have been reported. (author)

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

    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

    Hnsch, 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. Dispersion stability of functionalized graphene in aqueous sodium dodecyl sulfate solutions.

    Hsieh, Andrew G; Korkut, Sibel; Punckt, Christian; Aksay, Ilhan A

    2013-12-01

    The colloidal stability of functionalized graphene sheets (FGSs) in aqueous sodium dodecyl sulfate (SDS) solutions of different concentrations was studied by optical microscopy and ultraviolet-visible light absorption after first dispersing the FGSs ultrasonically. In up to ∼10 μM SDS solutions, FGSs reaggregated within a few minutes, forming ramified structures in the absence of SDS and increasingly compact structures as the amount of SDS increased. Above ∼10 μM, the rate of reaggregation decreased with increasing SDS concentration; above ∼40 μM, the suspensions were colloidally stable for over a year. The concentration of ∼40 μM SDS lies 2 orders of magnitude below the critical surface aggregation concentration of ∼1.8 mM SDS on FGSs but above the concentration (∼18 μM) at which SDS begins to form a monolayer on FGSs. Neither surface micelle nor dense monolayer coverage is therefore required to obtain stable aqueous FGS dispersions. We support our experimental results by calculating the van der Waals and electrostatic interaction energies between FGSs as a function of SDS concentration and show that the experimentally observed transition from an unstable to a stable dispersion correlates with a transition from negative to positive interaction energies between FGSs in the aggregated state. Furthermore, our calculations support experimental evidence that aggregates tend to develop a compact structure over time. PMID:24188504

  18. Effect of Bicarbonate Supplementation on Renal Function and Nutritional Indices in Predialysis Advanced Chronic Kidney Disease

    Jeong, Jiwon; Kwon, Soon Kil; Kim, Hye-Young

    2014-01-01

    Current practice guidelines recommend alkali therapy in patients with chronic kidney disease (CKD) and metabolic acidosis to prevent complications. This study aims to investigate the effect of oral sodium bicarbonate supplementation on the progression of renal function and nutritional indices in patients with predialysis advanced CKD. Forty patients with predialysis stage 5 CKD(estimated glomerular filtration rate, eGFR

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

    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 ...

  20. Techniques for extinguishing sodium fires

    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.)

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

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

    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

  3. Efeito alcalinizante de solues eletrolticas intravenosas com concentraes elevadas de lactato de sdio infundidas em bezerros sadios / Alkalinizing effect of intravenous electrolyte solutions with high sodium lactate concentrations infused in healthy calves

    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 solues eletrolticas com concentraes elevadas de lactato de sdio em bezerros sadios, foram idealizadas seis solues contendo 28, 56 e 84mEq/L de lactato (L28, L56 e L84) ou de bicarbonato (B28, B56 e B84), com concentraes de sdio, de [...] potssio e de clcio semelhantes s da soluo de Ringer com lactato (SRL). As solues contendo bicarbonato de sdio foram utilizadas como padro para comparao. Seis bezerros receberam, por via intravenosa, todas as seis solues, uma a cada vez, com intervalo de quatro a cinco dias entre as infuses, 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 infuso, na metade do volume, ao trmino e duas horas e meia aps o trmino da infuso. Determinaram-se concentrao de protena plasmtica total, pH sanguneo e urinrio, pCO2, HCO3 -, BE, concentrao plasmtica e urinria de lactato L e concentraes sricas e urinrias de Na+, K+, Cl- e creatinina. A soluo L28, idntica SRL, provocou discreto incremento da reserva alcalina e, consequentemente, produziu efeito alcalinizante insuficiente para a correo de estados de acidose metablica. A soluo L84, alm de provar-se segura, provocou o maior aumento da reserva alcalina, equivalente B84, e, assim, produziu efeito capaz de corrigir o grau moderado de acidose metablica. 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. tlpA gene expression is required for arginine and bicarbonate chemotaxis in Helicobacter pylori

    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.

  5. The antioxidant properties of oligo sodium alginates prepared by radiation-induced degradation in aqueous and hydrogen peroxide solutions

    In this study, the radiation-induced degradation of sodium alginates (NaAlg), having different guluronic acids (G) and mannuronic acid (M) ratios, (G/M), in aqueous and hydrogen peroxide solutions were investigated first; after that, the antioxidative properties of the oligo sodium alginates prepared were identified. Radiation degradation yield values, G(S), were determined for each irradiation condition and compared with those of the dry-state-irradiated NaAlg. The results showed that the oligo sodium alginates with M¯n from 1000 to 3750 Da could be easily prepared by γ-irradiation of NaAlg solution in the presence of small amount of hydrogen peroxide at low doses (below 5.0 kGy) and by controlling the G/M. The antioxidant properties of the fractions with various molecular weight and G/M were evaluated by determining the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH·), and 50% inhibition concentrations of LF120 NaAlg, which was irradiated in aqueous solution and H2O2 solution at a dose of 2.5 kGy and having number average molecular weights of 10.2 and 3.75 kDa were found to be 10.0 and 2.5 mg/ml, respectively. The results demonstrated that its molecular weight was an important factor in controlling the antioxidant properties of NaAlg, and due to the sharp decrease in molecular weight in the case of aqueous media irradiation the effect of G/M of initial polymer became unimportant whereas the dry-state-irradiated NaAlgs behaved conversely. - Highlights: ► The radiation-induced degradation of sodium alginates having different guluronic acids and mannuronic acid ratios. ► Degradation of NaAlg in aqueous solution in the presence or absence of hydrogen peroxide. ► Antioxidant properties of oligo sodium alginates.

  6. [Evaluation of motherś knowledge about oral rehydration therapy and sodium concentration in homemade sugar salt solutions

    Sena, L V; Maranhão, H de S; Moraes, M B

    2001-01-01

    OBJECTIVE: To evaluate motherś knowledge about oral rehydration therapy and to determine the concentration of sodium in sugar salt solutions prepared by the interviewed mothers. METHODS: Cross-sectional study of low-income families from the suburbs of Natal, a city in the state of Rio Grande do Norte. One hundred and thirty six households with children younger than 5 years were visited. The information on when to use the solution, how to administrate it and how to prepare it was provided by the interviewed mothers. The concentration of sodium was determined in 100 solutions prepared by those mothers. RESULTS: Only 9.0% of mothers had appropriate knowledge about when to use the solution and 21.0% knew how to administer it correctly. The error rates regarding the measurement of ingredients were: 2.5% for salt, 22.2% for water and 43.2% for sugar, according to the answers given by 81 mothers, who used a double-ended spoon made of plastic to measure quantities. In fifty percent of the analyzed samples, sodium was within safe limits (30 mmol/l to 100 mmol/l). Those considered dangerous (>100 mmol/l) or inefficient solutions (utensils were within acceptable limits (P=0.0001). CONCLUSION: Motherś knowledge about oral rehydration therapy was considered poor. Moreover, the concentration of sodium in sugar salt solutions seldom remains within safe limits, particularly those solutions in which the double-ended spoon was not used for preparation. These conclusions should be considered in future educational programs on oral rehydration. PMID:14647828

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

    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.

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

    Ganot, Yuval, E-mail: yuvalga@sapir.ac.il, E-mail: ibar@bgu.ac.il [Department of Engineering, Sapir Academic College, D. N. Hof Ashkelon 79165 (Israel); Bar, Ilana, E-mail: yuvalga@sapir.ac.il, E-mail: ibar@bgu.ac.il [Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)

    2015-09-28

    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 (NaNO{sub 3}), 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, ν{sub 1}(NO{sub 3}{sup −}), 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.

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

    Sokić 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. 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.

    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.

  11. 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

    A. V. Inda Junior

    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 extraiu 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.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 percent 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.

  12. 21 CFR 184.1721 - Sodium acetate.

    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...

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

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

    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

  15. Effect of temperature on solvation behaviour of diclofenac sodium salt in aqueous glycine and L-proline solutions

    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 Heplers 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

  16. Evidence for a Detrimental Effect of Bicarbonate Therapy in Hypoxic Lactic Acidosis

    Graf, Helmut; Leach, William; Arieff, Allen I.

    1985-02-01

    Lactic acidosis, a clinical syndrome caused by the accumulation of lactic acid, is characterized by lactate concentration in blood greater than 5 mM. Therapy usually consists of intravenous sodium bicarbonate (NaHCO3), but resultant mortality is greater than 60 percent. The metabolic and systemic effects of NaHCO3 therapy of hypoxic lactic acidosis in dogs were studied and compared to the effects of sodium chloride or no therapy. Sodium bicarbonate elevated blood lactate concentrations to a greater extent than did either sodium chloride or no treatment. Despite the infusion of NaHCO3, both arterial pH and bicarbonate concentration decreased by a similar amount in all three groups of dogs. Additional detrimental effects of NaHCO3 were observed on the cardiovascular system, including decreases in cardiac output and blood pressure that were not observed with either sodium chloride or no treatment. Thus there is evidence for a harmful effect of NaHCO3 in the treatment of hypoxic lactic acidosis.

  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

    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

    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. Complexing reactions in surfactant solutions. 1. Magnetic-relaxation study of a number of transition metal reactions with complexons in solutions of sodium alkyl sulfates

    The influence of decyl-, dodecyl- and tetradecyl-sulfates of sodium on the composition and stability of gadolinium (3) and some other metals with complexones (iminodiacetic, oxyethyliminodiacetic, nitriltriacetic acids) has been studied by the method of NM relaxation. An approach to quantitative description of complexing in solutions of anionic surfactants has been suggested. Binding constants of Gd3+ and H+ with micelles have been calculated by means of computer simulation

  20. High bicarbonate levels in narcoleptic children.

    Franco, Patricia; Junqua, Aurelie; Guignard-Perret, Anne; Raoux, Aude; Perier, Magali; Raverot, Veronique; Claustrat, Bruno; Gustin, Marie-Paule; Inocente, Clara Odilia; Lin, Jian-Sheng

    2016-04-01

    The objective of this study was to evaluate the levels of plasma bicarbonate levels in narcoleptic children. Clinical, electrophysiological data and bicarbonate levels were evaluated retrospectively in children seen in our paediatric national reference centre for hypersomnia. The cohort included 23 control subjects (11.5 ± 4 years, 43% boys) and 51 patients presenting de-novo narcolepsy (N) (12.7 ± 3.7 years, 47% boys). In narcoleptic children, cataplexy was present in 78% and DQB1*0602 was positive in 96%. The control children were less obese (2 versus 47%, P = 0.001). Compared with control subjects, narcoleptic children had higher bicarbonate levels (P = 0.02) as well as higher PCO2 (P Sleepiness Scale (P = 0.01). Narcoleptic patients without obesity often had bicarbonate levels higher than 27 mmol L (-1) (55 versus 25%, P = 0.025). No differences were found between children with and without cataplexy. In conclusion, narcoleptic patients had higher bicarbonate plasma levels compared to control children. This result could be a marker of hypoventilation in this pathology, provoking an increase in PCO2 and therefore a respiratory acidosis, compensated by an increase in plasma bicarbonates. This simple screening tool could be useful for prioritizing children for sleep laboratory evaluation in practice. PMID:26574184

  1. Bicarbonate utilization by leaf protoplasts from Potamogeton

    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

  2. Voltage clamp of the cardiac sodium current at 37 degrees C in physiologic solutions.

    Murray, K T; Anno, T.; Bennett, P B; Hondeghem, L M

    1990-01-01

    The cardiac sodium current was studied in guinea pig ventricular myocytes using the cell-attached patch voltage clamp at 37 degrees C in the presence of 145 mM external sodium concentration. When using large patch pipettes (access resistance, 1-2 M omega), the capacity current transient duration was typically 70 microseconds for voltage clamp steps up to 150 mV. At 37 degrees C the maximum inward sodium current peaked in approximately 200 microseconds after the onset of a clamp step and at th...

  3. Photocatalytic degradation of betamethasone sodium phosphate in aqueous solution using ZnO nanopowder

    Giahi, M.; Taghavi, H.; Habibi, S.

    2012-12-01

    The photocatalytic degradation of betamethasone sodium phosphate has been investigated in aqueous phase by using ultraviolet (UV) light and ZnO nanopowder. The effect of catalyst loading, irradiation time, pH, addition of oxidizers, effect of alcohol and anion presence on the reaction rate was ascertained and optimum conditions for maximum degradation were determined. The photocatalytic degradation of betamethasone sodium phosphate was strongly influenced by these parameters. The optimum amount of the photocatalyst used is 0.44 g/L. The efficiency of betamethasone sodium phosphate increases with the photo-degradation increase of the irradiation time.

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

    SALLES, Marcela Moreira; BADAR, Maurcio Malheiros; de ARRUDA, Carolina Noronha Ferraz; LEITE, Vanessa Maria Fagundes; da SILVA, Cludia Helena Lovato; WATANABE, Evandro; OLIVEIRA, Viviane de Cssia; 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

  5. Corrosion resistance of ?-solid solution and hardening ?'-phase of nickel alloys in sodium sulfate and chloride melts

    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

  6. Effect of concentration of sodium silicate solution in the synthesis of silica-coated magnetite nanoparticles by ultrasonication

    Fajaroh, Fauziatul; Sumari, Nazriati

    2016-02-01

    An ex-situ silica coating of magnetite nanoparticles synthesized electrochemically had been successfully carried out by ultrasonication. An aqueous solution of sodium silicate had been used as silica source.The Si-O-Si, Si-O and Fe-O-Si bonds on the surface of the silica-coated magnetite had been successfully identified using FTIR. Reduction in particle size due to the influence of ultrasound was studied using SEM. Enhancement in the specific surface area of the particles due to the silica coating and reduction in particle size was learned through BET analysis. The Characters of the resulting silica-coated magnetite were influenced by the concentration of sodium silicate solution. The greater the concentration of sodium silicate solution, the smaller the particle crystallinity and the larger the particles surface area was produced. The resulting silica-coated magnetite has a surface area of 38.171 to 67.993 m2/g, otherwise the non-coated particles only has a surface area of 27.894 m2/g. This silica-coated magnetite nanoparticles has more potent as an adsorbent than that of the bare magnetite. Besides that, the presence of silanol groups on its surface makes an opportunity for further functionalization needed for some applications.

  7. Comparison of 2% chlorhexidine and 5.25% sodium hypochlorite irrigating solutions on postoperative pain: A randomized clinical trial

    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.

  8. Oral salt supplements to compensate for jejunostomy losses: comparison of sodium chloride capsules, glucose electrolyte solution, and glucose polymer electrolyte solution.

    Nightingale, J M; Lennard-Jones, J E; Walker, E R; Farthing, M J

    1992-01-01

    Six patients with jejunostomies and residual jejunal lengths of 105 to 250 cm took the same food and water each day for eight study days. In random order, three methods of salt replacement were tested, each over 48 hours, against a period without added salt. During the three test periods the patients took 120 mmol of sodium chloride daily, as salt in gelatine capsules, as an isotonic glucose electrolyte (280 mOsmol/kg; 30 kcal) solution, and as a glucose polymer (Maxijul) solution (280 mOsmol...

  9. Analysis of the sodium recirculation theory of solute-coupled water transport in small intestine

    Larsen, Erik Hviid; Sørensen, Jakob Balslev; Sørensen, Jens Nørkaer

    permeabilities and pump constants of fluxes of water and electrolytes, volumes and ion concentrations of cell and lateral intercellular space (lis), and membrane potentials and conductances. Simulating physiological bioelectrical features together with cellular and paracellular fluxes of the sodium ion...

  10. Sodium-water steam generator safety problems and their solution in the USSR

    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

  11. Inhibition of cobalt active dissolution by benzotriazole in slightly alkaline bicarbonate aqueous media

    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.

  12. Transplastomic integration of a cyanobacterial bicarbonate transporter into tobacco chloroplasts.

    Pengelly, J J L; Förster, B; von Caemmerer, S; Badger, M R; Price, G D; Whitney, S M

    2014-07-01

    Improving global yields of agricultural crops is a complex challenge with evidence indicating benefits in productivity are achieved by enhancing photosynthetic carbon assimilation. Towards improving rates of CO2 capture within leaf chloroplasts, this study shows the versatility of plastome transformation for expressing the Synechococcus PCC7002 BicA bicarbonate transporter within tobacco plastids. Fractionation of chloroplast membranes from transplastomic tob(BicA) lines showed that ~75% of the BicA localized to the thylakoid membranes and ~25% to the chloroplast envelope. BicA levels were highest in young emerging tob(BicA) leaves (0.12 μmol m(-2), ≈7mg m(-2)) accounting for ~0.1% (w/w) of the leaf protein. In these leaves, the molar amount of BicA was 16-fold lower than the abundant thylakoid photosystem II D1 protein (~1.9 μmol m(-2)) which was comparable to the 9:1 molar ratio of D1:BicA measured in air-grown Synechococcus PCC7002 cells. The BicA produced had no discernible effect on chloroplast ultrastructure, photosynthetic CO2-assimilation rates, carbon isotope discrimination, or growth of the tob(BicA) plants, implying that the bicarbonate transporter had little or no activity. These findings demonstrate the utility of plastome transformation for targeting bicarbonate transporter proteins into the chloroplast membranes without impeding growth or plastid ultrastructure. This study establishes the span of experimental measurements required to verify heterologous bicarbonate transporter function and location in chloroplasts and underscores the need for more detailed understanding of BicA structure and function to identify solutions for enabling its activation and operation in leaf chloroplasts. PMID:24965541

  13. The chemical interactions of sodium with urania, plutonia and their solid solutions

    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

    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. Bicarbonate-Regulated Soluble Adenylyl Cyclase

    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.

  16. Rheological properties of pullulan-sodium alginate based solutions during film formation.

    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 50C 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

  17. Lactated Ringer's solution or 0.9% sodium chloride as fluid therapy in pigeons (Columba livia submitted to humerus osteosynthesis

    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.

  18. Effect of lithium on the properties of a liquid crystal formed by sodium dodecylsulphate and decanol in aqueous solution

    Bahamonde-Padilla, V. E.; Espinoza, Javier; Weiss-Lpez, B. E.; Cascales, J. J. Lpez; 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.

  19. Experimental investigation of the kinetics of hydrolysis of sodium borohydride aqueous-alkaline solutions

    Nesteruk, A. A.; Kalinin, V. I.; Minkina, V. G.; Martynenko, V. V.; Shabunya, S. I.

    2011-09-01

    Distinctive features of an experimental procedure for determination of the conversion of sodium borohydride in hydrolysis in an aqueous-alkaline medium are described; the procedure is based on measuring the amount of the released hydrogen. Technical and methodological features of implementation of this procedure and measurement errors are discussed; a technique for calculation of the conversion of sodium borohydride in hydrolysis is presented. Experimental data in the form of the constants of a quasistationary hydrolysis regime are given for different isothermal conditions. The range of experiments covers temperatures from 20 to 95°C and alkali concentrations from 10-2 to 5 M.

  20. Model investigations for trace analysis of iodine, uranium, and technetium in saturated sodium chloride leaching solutions of stored radioactive waste

    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. The antioxidant properties of oligo sodium alginates prepared by radiation-induced degradation in aqueous and hydrogen peroxide solutions

    Şen, Murat; Atik, Hanife

    2012-07-01

    In this study, the radiation-induced degradation of sodium alginates (NaAlg), having different guluronic acids (G) and mannuronic acid (M) ratios, (G/M), in aqueous and hydrogen peroxide solutions were investigated first; after that, the antioxidative properties of the oligo sodium alginates prepared were identified. Radiation degradation yield values, G(S), were determined for each irradiation condition and compared with those of the dry-state-irradiated NaAlg. The results showed that the oligo sodium alginates with M from 1000 to 3750 Da could be easily prepared by γ-irradiation of NaAlg solution in the presence of small amount of hydrogen peroxide at low doses (below 5.0 kGy) and by controlling the G/M. The antioxidant properties of the fractions with various molecular weight and G/M were evaluated by determining the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl free radical (DPPHrad ), and 50% inhibition concentrations of LF120 NaAlg, which was irradiated in aqueous solution and H2O2 solution at a dose of 2.5 kGy and having number average molecular weights of 10.2 and 3.75 kDa were found to be 10.0 and 2.5 mg/ml, respectively. The results demonstrated that its molecular weight was an important factor in controlling the antioxidant properties of NaAlg, and due to the sharp decrease in molecular weight in the case of aqueous media irradiation the effect of G/M of initial polymer became unimportant whereas the dry-state-irradiated NaAlgs behaved conversely.

  2. Behaviour of 29Si NMR and infrared spectra of aqueous sodium and potassium silica solutions as a function of (SiO2/M2+O) ratio

    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. Effects of Immersion Solutions on Characteristics and Consumer Preference of Cassava

    Syarifah Aminah

    2013-01-01

    Full Text Available Indonesia's rice consumption reached 139 kg / capita / year. This figure is still quite high compared to other countries in Asia, such as Japan (60 kg / capita / year. That condition indicated that consumption of carbohydrates in Indonesia is still dominated by rice, which reached 78%. Many efforts to decrease the consumption of rice are needed, and one of them is to optimize the utilization of cassava into cassava rice. This research was aimed to assess technologies in production process of cassava rice which applicable at farmer level and also can be accepted by consumers. This experiments used Completely Randomized Design with 5 replications. Treatments consists of various types of marinade solution, namely 1 sodium bicarbonate 2%, 2 metaphosphate 0.1%, 3 sodium bicarbonate + metaphosphate 2% + 0.1%, and 4 running water. The stages of production process were:  sortation of  rice cassava, cassava bark stripping, washing, soaking, draining, pressing, drying, and filtering. Parameter observations consist of moisture content, ash content, protein content, fat content, carbohydrate content. Organoleptic tests on rice cassava include color, taste, aroma, firmness, stickiness and eating palatability. The results showed that the moisture content of the rice cassava range 4.419% - 5.378%, ash content was 0.171% - 0.182%, protein content was 1.745% - 2.024%, fat content of 0.792% - 0.930%, and carbohohidrate level was 91.693% - 92.564%. Meanwhile, organoleptic tests showed that the treatment of type marinade gave significant effects on the color, flavor, aroma, touchness/elasticity and eating palability, except the level of stickiness. Soaking with sodium bicarbonate and metaphosphate causing cassava rice color became brighter and also gave higher valuation by panelists ( 5.8 = like. Moreover, panelists gave 5.2 points (like on eating palability to sample with treated by immersion in tap water without the use of sodium bicarbonate and metaphospahate but not significantly different from soaking with sodium bicarbonate.

  4. Preparation of Organized Mesoporous Silica from Sodium Metasilicate Solutions in Alkaline Medium using Nonionic Surfactants

    Zukalová, Markéta; Rathouský, Jiří; Zukal, Arnošt

    2003-01-01

    Roč. 68, č. 10 (2003), s. 2019-2031. ISSN 0010-0765 Institutional research plan: CEZ:AV0Z4040901 Keywords : mesoporous SiO2 * sodium metasilicate * nonionic surfactants Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.041, year: 2003

  5. The Corrosion Behavior of Nickel and Inconel 600 in Sodium Hydroxide and Hydrochloric Acid Solution at 280 .deg. C

    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

  6. Study of thermodynamic properties of solution of ampicillin sodium in methanol at T = 298.15 k.

    Azamat, Jafar; Sardroodi, Jaber Jahanbin

    2014-01-01

    Osmotic coefficients of the solution of Ampicillin sodium in methanol at T = 298.15 K were measured using the isopiestic technique and head space-gas chromatography. The experimental osmotic coefficients have been correlated using the ion interaction model of Pitzer, e-NRTL model of Chen, NRF and a fourth- order polynomial in terms of molality. In this work, reference solution is NaI-CH(3)OH. The vapor pressures of the solutions and the solvent activities have been calculated from the osmotic coefficients. Reliability of the models in expression of the osmotic coefficients were compared on the basis of standard deviation of the fittings. The best fit of experimental osmotic coefficients data have been obtained by the Pitzer based ion interaction model. PMID:25551730

  7. Effect of Polyvnylpyrrolidone (PVP) in Binary Solution on the Performance of Polyethersulfone Hollow Fibre Membrane for Sodium Chloride Separation

    Bolong, N.; Ismail, A. F.; Salim, M. R.

    2010-03-01

    In membrane preparation, phase inversion is a versatile technique that allow polymer to be transformed from liquid to a solid state in a controlled manner. The preparation and process involves many factors and parameters specifically in fabricating hollow fibre membrane. In this study, dope solution factor in the process of fabricating hollow fibre membrane were explored. The effects of polymer concentration and polyvinylpyrrolidone (PVP) as additive in the dope solution on the morphology and separation performance were found able to produced high porous membranes, well interconnected pores and surface properties. Employing polyethersulfone (PES) as polymer, hollow fibre membranes were fabricated using N-methyl-2-pyrrolidone (NMP) as solvent and using water as the external coagulant. Finally the fabricated ultrafiltration membranes were characterized and evaluated based on solute transport concentration (sodium chloride) and pure water permeation properties.

  8. Caffeine, but not bicarbonate, improves 6 min maximal performance in elite rowers

    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....

  9. Effectiveness of sodium benzoate as a freshwater low toxicity antifoulant when dispersed in solution and entrapped in silicone coatings.

    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

  10. Solution combustion synthesis and characterization of lead-free piezoelectric sodium niobate (NaNbO3) powders

    Research highlights: → This work reports the preparation of lead-free piezoelectric sodium niobate (NaNbO3) by using solution combustion methods. Crystalline NaNbO3 powder was directly synthesized via the solution combustion process using NaNO3, Nb2O5 and glycine. The fuel-to-oxidizer molar ratio was found to affect the combustion reaction and character of the powder obtained. This method is a simple, rapid, cost- and time-saving way of synthesizing stoichiometric, homogeneous and fine NaNbO3 powder with a low calcination temperature. - Abstract: Nano-crystalline sodium niobate (NaNbO3) powder was synthesized by the solution combustion synthesis of sodium nitrate (NaNO3) and Nb2O5 using glycine as the fuel. The chemical reaction, nucleation mechanisms and influence of the fuel-to-oxidizer ratio to phase formation were studied. The precursor and product powders were characterized, using thermo gravimetric analysis (TGA), differential thermal analysis (DTA), the X-ray diffraction technique (XRD), scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. As-prepared powder possesses an orthorhombic crystal structure with an X-ray diffraction pattern that could be matched with the perovskite, NaNbO3 JCPDS no. 82-0606. Perovskite NaNbO3 phase, with a mean crystalline size (calculated by X-ray line broadening) ranging from 44.51 ± 11.99 nm (ratio of 0.7) to 26.11 ± 13.69 nm (ratio of 2.0) was obtained. The SEM image shows polyhedral-shaped powder with a mean particle size of 137 ± 52 nm and 226 ± 46 nm for as-prepared and calcined powder, respectively.

  11. Effect of Bicarbonate on the Mineralization of Methyldiethanolamine by using UV/H2O2

    Sabtanti Harimurti

    2014-01-01

    Full Text Available The presence of bicarbonate affects the degradation efficiency of effluents containing aqueous methyldiethanolamine (MDEA solution leaving the CO2 absorption/regeneration unit of natural gas processing units. In the present study the effect of bicarbonate at three different pH conditions of (acidic, neutral and alkaline simulated MDEA solution were conducted, by the addition of six different concentration of NaHCO3 (0.025, 0.05, 0.075, 0.1, 0.125 and 0.15 M. The presence of bicarbonate increased the mineralization of MDEA when the reaction was conducted at neutral initial pH conditions, where as the MDEA mineralization was reduced when the reaction was conducted at alkaline pH condition.

  12. Electrochemical and spectroscopic studies of uranium(IV), -(V), and -(VI) in carbonate-bicarbonate buffers

    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

  13. Bicarbonate adsorption band of the chromatography for carbon isotope separation using anion exchangers

    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)

  14. Diffusion coefficients of sodium fluoride in aqueous solutions at 298.15 k and 310.15 k.

    Ribeiro, Ana C F; Lobo, Victor M M; Sobral, Abilio J F N; Soares, Helder T F C; Esteso, Ana R J; Esteso, Miguel A

    2010-06-01

    Mutual diffusion coefficients (interdiffusion coefficients) have been measured for sodium fluoride in water at 298.15 K and 310.15 K at concentrations between 0.003 mol dm-3 and 0.05 mol dm-3. The diffusion coefficients were measured using a conductimetric cell. The experimental mutual diffusion coefficients are discussed on the basis of the Onsager-Fuoss model. The limiting molar conductivity of the fluoride ion in these solutions at 310.15 K has been estimated using these results. PMID:24061738

  15. The effect of sodium hypochlorite solutions on in vitro seedling growth and shoot regeneration of flax (Linum usitatissimum)

    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.

  16. Shock Hugoniot and equations of states of water, castor oil, and aqueous solutions of sodium chloride, sucrose and gelatin

    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.

  17. Electrochemical evaluation of sodium metabisulfite as environmentally friendly inhibitor for corrosion of aluminum alloy 6061 in a chloride solution

    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

  18. Electrochemical evaluation of sodium metabisulfite as environmentally friendly inhibitor for corrosion of aluminum alloy 6061 in a chloride solution

    Zaid, B., E-mail: zaidbachir@yahoo.com [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Maddache, N.; Saidi, D. [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Souami, N. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Bacha, N. [Département de Mécanique, Université SAAD Dahleb, Blida (Algeria); Si Ahmed, A. [Im2np, UMR 7334 CNRS, Aix-Marseille Université, 13397 Marseille Cedex 20 (France)

    2015-04-25

    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 (Na{sub 2}S{sub 2}O{sub 5}) on pitting corrosion of 6061 aluminum alloy, in 5 × 10{sup −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 Na{sub 2}S{sub 2}O{sub 5} 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.

  19. Use of sodium hetastarch (Hespan) solution for reduction of postoperative adhesion formation in rabbits.

    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

  20. Effect of Sodium Chloride on the Surface and Wetting Properties of Aqueous Solutions of Cocamidopropyl Betaine

    Staszak, Katarzyna; Wieczorek, Daria; Michocka, Katarzyna

    2014-01-01

    Surfactants are important ingredients of personal care products and household products. The main characteristic of these compounds is to decrease the surface tension of solvent and resulting many properties such as contact angle, foam properties etc. The coexistence of other ingredients in the product may affect the properties of surfactants. One of the main components contained in almost every personal care and household product is sodium chloride. The main aim of this work was to determine ...

  1. Numerical solution of melted sodium around the tubes which involves Uranium by finite volume method

    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.

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

    Thomas, J. L.; Roeselová, Martina; Dang, L. X.; Tobias, D. J.

    2007-01-01

    Roč. 111, č. 16 (2007), s. 3091-3098. ISSN 1089-5639 R&D Projects: GA MŠk 1P05ME798; GA MŠk LC512 Grant ostatní: NSF(US) CHE-0209719; NSF(US) CHE-0431312 Institutional research plan: CEZ:AV0Z40550506 Keywords : aqueous sodium nitrate * air -water interface * molecular dynamics simulation Subject RIV: CC - Organic Chemistry Impact factor: 2.918, year: 2007

  3. Sodium phthalamates as corrosion inhibitors for carbon steel in aqueous hydrochloric acid solution

    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.

  4. Volumetric and isentropic compressibility behaviour of aqueous solutions of (polyvinylpyrrolidone + sodium citrate) at T = (283.15 to 308.15) K

    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.

  5. Volumetric and isentropic compressibility behaviour of aqueous solutions of (polyvinylpyrrolidone + sodium citrate) at T = (283.15 to 308.15) K

    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

  6. Infrared optical constants of crystalline sodium chloride dihydrate: application to study the crystallization of aqueous sodium chloride solution droplets at low temperatures.

    Wagner, Robert; Mhler, Ottmar; Schnaiter, Martin

    2012-08-23

    Complex refractive indices of sodium chloride dihydrate, NaCl2H(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. NaCl2H(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 NaCl2H(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 NaCl2H(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 NaCl2H(2)O particles. Compared to the findings on the NaCl/NaCl2H(2)O partitioning from a recent study conducted with micron-sized NaCl particles deposited onto a surface, the transition regime from NaCl to NaCl2H(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

  7. The absorption spectra of Pu(VI), -(V) and -(IV) produced electrochemically in carbonate-bicarbonate media

    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)

  8. 21 CFR 582.1613 - Potassium bicarbonate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium bicarbonate. 582.1613 Section 582.1613 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose...

  9. 21 CFR 184.1613 - Potassium bicarbonate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium bicarbonate. 184.1613 Section 184.1613 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS...

  10. Study of gaseous iodine absorption in water and aqueous solutions of sodium hydroxyde

    Experiments were done in an agitated vessel containing the solution at its bottom; gaseous iodine was flowing above the liquid surface. Study of absorption rate versus gaseous iodine concentration, product concentrations in solution, gaseous flow rate, stirring rate of the solution and temperature shows three regimes: in water, the rate controlling phenomenon is the liquid side diffusion; in concentrated soda solutions (>0.25M/l), gaseous phase diffusion is rate controlling. In dilute soda solutions, product diffusion rates in the two phases and chemical reaction kinetics both determine absorption rate

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

    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 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. Successful recovery from iatrogenic severe hypernatremia and severe metabolic acidosis resulting from accidental use of inappropriate bicarbonate concentrate for hemodialysis treatment

    Bhosale, Guruprasad P.; Shah, Veena R.

    2015-01-01

    Bicarbonate dialysis is the treatment modality of choice for correction of metabolic acidosis in chronic renal failure. However, improper selection of dialysate concentrate can result in life-threatening human errors. We report a case of iatrogenic severe hypernatremia (sodium 207 mEq/L) and severe metabolic acidosis (pH 6.65) that resulted due to accidental use of inappropriate bicarbonate concentrate for hemodialysis treatment. There was successful recovery in this patient with no neurologi...

  13. Phase equilibria diagrams, crystal growth peculiarities and Raman investigations of lead and sodium-bismuth tungstate-molybdate solid solutions

    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.

  14. Inorganic polymers from laterite using activation with phosphoric acid and alkaline sodium silicate solution: Mechanical and microstructural properties

    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

  15. Inorganic polymers from laterite using activation with phosphoric acid and alkaline sodium silicate solution: Mechanical and microstructural properties

    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.

  16. In vitro bioactivity of soda lime borate glasses with substituted SrO in sodium phosphate solution

    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.

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

    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.

  18. A fiber-optic sensor using an aqueous solution of sodium chloride to measure temperature and water level simultaneously.

    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

  19. Localized corrosion of alloys C-276 and 625 in aerated sodium chloride solutions at 25 to 200 degrees C

    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

  20. The thermodynamic properties of solutions of sodium chloride, water, and 1-propanol

    Mamontov, M. N.; Konstantinova, N. M.; Veryaeva, E. S.; Uspenskaya, I. A.

    2010-07-01

    The temperature-concentration dependences of the activity coefficient of NaCl in aqueous solutions of 1-propanol at 298 and 318 K, solution ionic strength up to 3 m, and alcohol contents of 10-40 wt % were determined by the method of electromotive forces with ion-selective electrodes. The results were used to estimate interaction parameters in the Pitzer model. The Darken method was used to calculate the integral Gibbs energy of solutions.

  1. Attenuation coefficients of sodium chloride for 662 keV ?-radiation, measured in dilute solutions

    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)

  2. Apparatus for the production of hydrogen from sodium borohydride in alkaline solution

    Pozio, A.; De Francesco, M.; Monteleone, G.; Oronzio, R.; Galli, S. [ENEA CR Casaccia, Via Anguillarese, 301 - 000123 Rome (Italy); D' Angelo, C.; Marrucci, M. [Erredue s.r.l., Via G.Gozzano, 3 - 57121 Livorno (Italy)

    2008-01-15

    Extended application of hydrogen as energy carrier demands an economical, safe and reliable technology for storage. In particular, chemical hydrides appear as capable and promising to overcome the issues related to hydrogen safety and handling and to be considered competitive with respect to conventional fuels. In the present work the production of hydrogen from the sodium borohydride (NaBH{sub 4}) reaction has been studied by experimental bench tests. Promising results on the NaBH{sub 4} hydrolysis, catalyst performance and stability have allowed practical application of this technology in a brand new commercial device for small laboratory production of hydrogen gas. A hydrogen generator prototype was manufactured and tested by Erredue srl (Italy). Results confirm an effective operation of the device and stable behaviour of the hydrolysis catalyst material. Experimental results and modeling approach are shown here. The reduction of sodium borohydride production cost and the new recycling methods for its reaction product appear as the critical issues, and R and D targets to solve them for a widespread energy application. (author)

  3. Sodium carbonate as phase promoter in aqueous solutions of imidazolium and pyridinium ionic liquids

    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.

  4. Effect of solution pH on electrochemical oxidation of iodide ion at platinum electrode in sodium perchlorate solution

    In first several days during the severe accident of nuclear power plants, radioactive iodine-131 is one of the most hazardous volatile fission products which could be released from fuels of nuclear reactors. Due to its high radioactivity, high fission yield up to 2% and hazardous biological effects, many research groups have been studied the chemical behavior of iodine species. Iodine is reported to be released from the fuels as a cesium iodide form, CsI. And, as nuclear fuels are mostly placed in the water pool, it is easily dissolved in the water after released from the fuels. In water, iodide anion could be oxidized into molecular iodine. As the molecular iodine is a volatile species and the oxidizing rate is affected by many environmental facts such as pH, radiolysis products and temperature, the oxidation reaction of the iodide ion has been considered as an important chemical reaction related to the severe accident of nuclear power plants. In present work, the effect of the solution pH on the electrochemical oxidation of iodide anion was carried out using linear sweep voltammetry (LSV) technique in different pH solutions. We confirmed that the electrochemical oxidation reaction of iodide into iodine at Pt electrode is independent on the solution pH

  5. Comparison of two cathartic preparations, peg-electrolytes solution and sodium phosphate salts, as means for large bowel preparation for colonoscopy

    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

  6. Influence of chloride, carbonate an bicarbonate ions on pitting corrosion of stainless steels

    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

  7. Migration behaviour of 14C labelled bicarbonate, HTO and 131I in boom clay

    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.)

  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

    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. Interactions of glutamine dipeptides with sodium dodecyl sulfate in aqueous solution measured by volume, conductivity, and fluorescence spectra

    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,φo), standard partial molar volumes of transfer from water to aqueous SDS solutions (ΔtVo), the hydration number, partial molar expansibility (Eφo), 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.

  10. Comparison of the Antibacterial Effect of Sodium Hypochlorite and Aloe Vera Solutions as Root Canal Irrigants in Human Extracted Teeth Contaminated with Enterococcus Faecalis

    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...

  11. 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

    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

  12. Corrosion protection of aluminium pretreated by vinyltriethoxysilane in sodium chloride solution

    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.

  13. Attenuation coefficients of 123 keV γ-radiation by dilute solutions of sodium chloride

    The linear attenuation and mass attenuation (or absorption) coefficients of the 123 keV γ 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 γ-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)

  14. Effects of hypertonic sodium chloride solution on the electrophysiologic alterations caused by bupivacaine in the dog heart

    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.

  15. Stability of Melphalan in 0.9% Sodium Chloride Solutions Prepared in Polyvinyl Chloride Bags for Intravenous Injection.

    Desmaris, Romain-Pacôme; Mercier, Lionel; Paci, Angelo

    2015-09-01

    Melphalan is an alkylating agent frequently used in an intravenous formulation to treat hematologic malignancies and solid tumors in both adults and children. According to the manufacturer, melphalan is stable in sterile 0.9% sodium chloride for 90 min at room temperature (RT). Several authors have studied the stability of different concentrations of melphalan; however, most were not adapted to the current manufacturing process applied in pharmaceutical centralized units. This study was conducted to determine the stability of melphalan in 0.9% sodium chloride solutions at concentrations used for intravenous injection in practice. Melphalan is commonly prepared in diluted solutions ranging from 2 to 4 mg/ml for the treatment of adult patients and at lower concentrations (down to 0.5 mg/ml) for pediatric use. Accordingly, these were the three concentrations chosen for this study. Melphalan concentrations were measured with high-performance thin-layer chromatography (HPTLC). At RT, admixtures prepared at 4 mg/ml were stable for up to 8 h without protection from light; however, at lower concentrations, such as 0.5 and 2 mg/ml, stability did not exceed 2 h. When refrigerated, melphalan was stable for 24 h at 2 mg/ml; however, at 0.5 and 4 mg/ml, the drug was not stable. Melphalan solutions present with limited stability at 0.5, 2, and 4 mg/ml and are not adapted for delayed administration in pharmaceutical centralized units. However, at 4 mg/ml and at RT, a stability of 8 h is very interesting in practice and allows sufficient time for preparation, pharmaceutical control, transport, and administration. PMID:26178037

  16. INITIAL GROWTHING OF PARICÁ (Schizolobium amazonicum UNDER NUTRIENT OMISSION AND SODIUM IN NUTRITIVE SOLUTION

    Teresa Cristina Lara Lanza de Sá e Melo Marques

    2004-07-01

    Full Text Available This paper aimed to evaluate the production of dry matter in leaves, stems and roots, to identify the effect of nutritional deficiencies, and to describe visual symptoms of macro and micronutrients deficiencies in Shizolobium amazonicum Herb. Seedlings were grown in a greenhouse experiment in 13 treatments. The deficiencies due to macro and micronutrients markedly decreased the production of dry matter. The Schizolobium amazonicum showed different responses to treatments. In the first few weeks, the seeds were able to supply P in the necessary amount but, due to fast growth rates, N was the limiting factor at this stage. Nitrogen and Fe were the most limiting and Mg, S, and Cu, were the least limiting to growth. Sodium was also less limiting to growth.

  17. The reduction of sodium pertechnetate [99mTc] in hydrochloric acid solution

    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

  18. Low temperature fatigue behavior of Alloy 600 in sodium chloride solution

    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

  19. Pancreatic bicarbonate secretion involves two proton pumps

    Novak, Ivana; Wang, Jing; Henriksen, Katrine L.; Haanes, Kristian A; Krabbe, Simon; Nitschke, Roland; Hede, Susanne E

    2011-01-01

    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...... non-gastric H(+)-K(+)-ATPases. We measured intracellular pH and secretion in small ducts isolated from rat pancreas and showed their sensitivity to H(+)-K(+) pump inhibitors and ion substitutions. Gastric and non-gastric H(+)-K(+) pumps were demonstrated on RNA and protein levels, and pumps were...... 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...

  20. A method of calculating quartz solubilities in aqueous sodium chloride solutions

    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.

  1. Evaluation of Perrhenate Spectrophotometric Methods in Bicarbonate and Nitrate Media.

    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

  2. Uranium release from boom clay in bicarbonate media

    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.)

  3. The interaction of phosphate coatings on a carbon steel surface with a sodium nitrite and silicate solution

    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.

  4. One-step synthesis of silica-coated magnetite nanoparticles by electrooxidation of iron in sodium silicate solution

    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.

  5. Polyvinyl pyrrolidone capped fluorescent anthracene nanoparticles for sensing fluorescein sodium in aqueous solution and analytical application for ophthalmic samples.

    Bhopate, Dhanaji P; Mahajan, Prasad G; Garadkar, Kalyanrao M; Kolekar, Govind B; Patil, Shivajirao R

    2015-11-01

    Based on the known complexation ability between polyvinyl pyrrolidone (PVP) and fluorescein sodium (FL Na(+)), fluorescent PVP capped anthracene nanoparticles (PVP-ANPs) were prepared using a reprecipitation method for detection of fluorescein in aqueous solution using the fluorescence resonance energy transfer (FRET) approach. A dynamic light scattering histogram of PVP-ANPs showed narrower particle size distribution and the average particle size was 15 nm. The aggregation-induced enhanced emission (AIEE) of PVP-ANPs was red shifted from its monomer by 1087.22 cm(-1). The maximum emission was seen to occur at 420 nm. The presence of FL Na(+) in the vicinity of PVP-ANPs quenched the fluorescence of PVP-ANPs because of its adsorption on the surface of PVP-ANPs in aqueous suspension. The FL Na(+) and PVP-ANPs were brought close enough, typically to 7.89 nm, which was less than the distance of 10 nm that is required between the energy donor-acceptor molecule for efficient FRET. The quenching results fit into the Stern-Volmer relationship even at temperatures greater than ambient temperatures. The thermodynamic parameters determined from FRET results helped to propose binding mechanisms involving hydrophobic and electrostatic molecular interaction. The fluorescence quenching results were used further to develop an analytical method for estimation of fluorescein sodium from ophthalmic samples available commercially in the market. PMID:25736374

  6. One-step synthesis of silica-coated magnetite nanoparticles by electrooxidation of iron in sodium silicate solution

    Setyawan, Heru, E-mail: sheru@chem-eng.its.ac.id [Sepuluh Nopember Institute of Technology, Department of Chemical Engineering, Faculty of Industrial Technology (Indonesia); Fajaroh, Fauziatul [Malang State University, Department of Chemistry, Faculty of Mathematics and Science (Indonesia); Widiyastuti, W.; Winardi, Sugeng [Sepuluh Nopember Institute of Technology, Department of Chemical Engineering, Faculty of Industrial Technology (Indonesia); Lenggoro, I. Wuled [Tokyo University of Agriculture and Technology, Institute of Symbiotic Science and Technology (Japan); Mufti, Nandang [Malang State University, Department of Physics, Faculty of Mathematics and Science (Indonesia)

    2012-03-15

    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{sup -1}, which is lower than the saturation magnetization of the Fe{sub 3}O{sub 4} bulk materials (M{sub s} = 92 emu g{sup -1}). This facile method appears to be promising as a synthetic route for producing silica-coated magnetite nanoparticles.

  7. 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

    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)

  8. Radiolysis of concentrated solutions of sodium nitrate in D2O

    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

  9. Ion-exchange equilibria of tungsten in the ionite-sodium sulfate sulfuric acid solution system

    Ion-exchange equilibrium in the system macroporous ionite-Na2WO4-Na2SO4-H2O(H2SO4) are studied by the methods of IR- and absorption spectroscopy, electron microscopy and mercury porometry to develop methods for tungsten selective extraction from solutions mentioned. It is ascertained that amine-containing macroporous anionites features a high exchange capacity towards tungsten ions in sulfate solutions at pH 2.5-5.5. The anionites permit a complete separation of tungsten ions from sulfate ions and preparation of pure tungsten salts

  10. Formation of Rod Shape Secondary Aggregation of Copper Nanoparticles in Aqueous Solution of Sodium Borohydride with Stabilizing Polymer

    Morphological variations of copper nanoparticles synthesized by the reduction of copper acetate with sodium borohydride in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) have been investigated. The results indicate that the specific rod shape secondary aggregation of copper nanoparticles are formed in the case that the oxygen is dissolved in the reacting solutions. Furthermore, it is also demonstrated that the copper nanorods with the aspect ratio of 2 - 20 and the average short axis length of 5 nm are synthesized in the weak oxidizing ambiance with a medium amount of PVP. The anomalous variations of copper nanoparticles are explained by the alignments of precursor copper ions and their reducing rates, which are modified by the density of resolved oxygen and the amount of PVP

  11. Improving the direct borohydride fuel cell performance with thiourea as the additive in the sodium borohydride solution

    Celik, Cenk; Sarac, Halil Ibrahim [Department of Mechanical Engineering, Kocaeli University, 41380 Kocaeli (Turkey); Boyaci San, Fatma Gul [TUeBiTAK Marmara Research Centre, Energy Institute, 41470 Gebze, Kocaeli (Turkey)

    2010-08-15

    In this study, the effects of the additive thiourea (TU) have been investigated under steady state/steady-flow and uniform state/uniform-flow systems with the aim of minimizing the anodic hydrogen evolution on Pd in order to increase the performance of a direct borohydride fuel cell. The fuel cell has consisted of Pd/C anode, Pt/C cathode and Na{sup +} form Nafion membrane as the electrolyte. There has been a small improvement in peak power density and fuel utilization ratio by addition of TU (1.6 x 10{sup -3} M) into the sodium borohydride solution; the peak power densities of 14.4 and 15.1 mW cm{sup -2}, and fuel utilization ratios of 21.6% and 23.2% have been obtained without and with TU, respectively. (author)

  12. Formation of Rod Shape Secondary Aggregation of Copper Nanoparticles in Aqueous Solution of Sodium Borohydride with Stabilizing Polymer

    Harada, Takuya; Fujiwara, Hidemichi

    2007-03-01

    Morphological variations of copper nanoparticles synthesized by the reduction of copper acetate with sodium borohydride in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) have been investigated. The results indicate that the specific rod shape secondary aggregation of copper nanoparticles are formed in the case that the oxygen is dissolved in the reacting solutions. Furthermore, it is also demonstrated that the copper nanorods with the aspect ratio of 2 - 20 and the average short axis length of 5 nm are synthesized in the weak oxidizing ambiance with a medium amount of PVP. The anomalous variations of copper nanoparticles are explained by the alignments of precursor copper ions and their reducing rates, which are modified by the density of resolved oxygen and the amount of PVP.

  13. Formation of Rod Shape Secondary Aggregation of Copper Nanoparticles in Aqueous Solution of Sodium Borohydride with Stabilizing Polymer

    Harada, Takuya [Nanotechnology Center, Yokohama Laboratory, The Furukawa Electric Co., Ltd., 500 Kiyotaki, Nikko 321-1493 (Japan); Fujiwara, Hidemichi [Nanotechnology Center, Yokohama Laboratory, The Furukawa Electric Co., Ltd., 500 Kiyotaki, Nikko 321-1493 (Japan)

    2007-03-15

    Morphological variations of copper nanoparticles synthesized by the reduction of copper acetate with sodium borohydride in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) have been investigated. The results indicate that the specific rod shape secondary aggregation of copper nanoparticles are formed in the case that the oxygen is dissolved in the reacting solutions. Furthermore, it is also demonstrated that the copper nanorods with the aspect ratio of 2 - 20 and the average short axis length of 5 nm are synthesized in the weak oxidizing ambiance with a medium amount of PVP. The anomalous variations of copper nanoparticles are explained by the alignments of precursor copper ions and their reducing rates, which are modified by the density of resolved oxygen and the amount of PVP.

  14. AFM study of the early corrosion of a high strength steel in a diluted sodium chloride solution

    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

  15. PtRu-LiCoO 2—an efficient catalyst for hydrogen generation from sodium borohydride solutions

    Krishnan, Palanichamy; Yang, Tae-Hyun; Lee, Won-Yong; Kim, Chang-Soo

    Hydrogen generation by the hydrolysis of aqueous sodium borohydride (NaBH 4) solutions is studied using IRA-400 anion resin dispersed Pt, Ru catalysts and lithium cobalt oxide (LiCoO 2) supported Pt, Ru and PtRu catalysts. The performance of the LiCoO 2 supported catalysts is better than that of ion-exchange resin dispersed catalysts. There is a marked concentration dependence on the performance of the LiCoO 2 supported catalysts and the hydrogen generation rate decreases if the borohydride concentration is increased beyond 10 wt.%. The efficiency of PtRu-LiCoO 2 is almost double that of either Ru-LiCoO 2 or Pt-LiCoO 2 for NaBH 4 concentrations up to 10 wt.%.

  16. Experimental investigation of aluminum complexing with sodium ion and of gallium and iron (III) speciation in natural solutions

    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)

  17. Study on Corrosion Performance of Cu-Te-Se Alloys in a 3.5% Sodium Chloride Solution

    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.

  18. Sodium diethyldithiocarbamate as a corrosion inhibitor of cold rolled steel in 0.5 M hydrochloric acid solution

    Graphical abstract: Relationship between corrosion current density (icorr), inhibition efficiency (ηp) and temperature with and without DDTC. (solid symbols: icorr, open symbols: ηp.) Highlights: ► DDTC can acts as a cathodic type inhibitor for CRS in HCl solution. ► The activation energy, Ea, increases with increasing the concentration of DDTC. ► The driving force for adsorption of DDTC on CRS is the increase in entropy. ► DDTC adsorbs on CRS surface probably by chemisorption and physisorption. ► Variation of DDTC results in different effect for time on inhibition efficiency. - Abstract: Sodium diethyldithiocarbamate (DDTC) as a corrosion inhibitor for cold rolled steel (CRS) in 0.5 M HCl solution was investigated by Tafel polarization and electrochemical impedance spectroscopy (EIS). All the data indicate that DDTC can inhibit the corrosion of CRS in HCl solution. Polarization data show that DDTC mainly acts as a good inhibitor though it can accelerate the anodic reaction somewhat. Adsorption of DDTC is found to follow the Langmuir adsorption isotherm. Thermodynamic analysis indicates that both physisorption and chemisorption probably occur in the adsorption process. SEM and FTIR results further validate that DDTC can adsorb on CRS surface.

  19. Hydrogen generation from catalytic hydrolysis of sodium borohydride solution using Cobalt-Copper-Boride (Co-Cu-B) catalysts

    Ding, Xin-Long; Yuan, Xianxia; Jia, Chao; Ma, Zi-Feng [Department of Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2010-10-15

    Co-Cu-B, as a catalyst toward hydrolysis of sodium borohydride solution, has been prepared through chemical reduction of metal salts, CoCl{sub 2}.6H{sub 2}O and CuCl{sub 2}, by an alkaline solution composed of 7.5wt% NaBH{sub 4} and 7.5wt% NaOH. The effects of Co/Cu molar ratio, calcination temperature, NaOH and NaBH{sub 4} concentration and reaction temperature on catalytic activity of Co-Cu-B for hydrogen generation from alkaline NaBH{sub 4} solution have been studied. X-ray diffraction (XRD), scanning electron microscope (SEM) and Nitrogen adsorption-desorption isotherm have been employed to understand the results. The Co-Cu-B catalyst with a Co/Cu molar ratio of 3:1 and calcinated at 400 C showed the best catalytic activity at ambient temperature. The activation energy of this catalytic reaction is calculated to be 49.6 kJ mol{sup -1}. (author)

  20. Development of planar, air-breathing, proton exchange membrane fuel cell systems using stabilized sodium borohydride solution

    Kim, Jin-Ho; Lee, Jae-Yong; Choi, Kyung-Hwan; Chang, Hyuk [Fuel Cell Group, Samsung Advanced Institute of Technology (SAIT), P.O. Box 111, Suwon (Korea)

    2008-12-01

    A planar, air-breathing, proton-exchange membrane fuel cell (PEMFC) system using a humidified H{sub 2} gas released from the hydrolysis of a stabilized sodium borohydride (NaBH{sub 4}) solution with a selected solid catalyst is extensively investigated as a promising energy storage system for mobile power sources. In economic terms, the passive air-breathing PEMFC is quite attractive because can its reliability, fuel utilization, and specific energy can be enhanced by removing auxiliary devices such as the air pump and the humidifier. The rate of hydrogen generation can be manually controlled by adjusting the amount of NaBH{sub 4} solution passed through the selected catalyst. In this study, the rate of hydrogen generation is varied from 0 to 18 cm{sup 3} min{sup -1} by controlling the mass transport of stabilized NaBH{sub 4} solution. The open-circuit voltage (OCV) and maximum power density are, respectively, 0.9 V and 128 mW cm{sup -2} at ambient temperature and pressure. Assuming a fuel conversion efficiency of 100%, the Faradic efficiency and energy efficiency of this system estimated to be 75% and 46%, respectively. In a planar 8-cell series-connected format, the maximum power density and cathode temperature are 3.1 W (103 mW cm{sup -2}) at 103 mW cm{sup -2} and 46 C, respectively. (author)

  1. Anodic behavior of nickel alloys in media containing bicarbonate ions

    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)

  2. A solubility model for aqueous solutions containing sodium, fluoride, and phosphate ions

    Weber, C.F.; Beahm, E.C.; Lee, D.D.; Watson, J.S.

    2000-02-01

    A significant problem in the processing of radioactive wastes is uncontrolled precipitation in solutions containing hydroxide, fluoride, and phosphate ions. A computational model is developed to calculate thermodynamic phase equilibria in aqueous solutions of fluoride, phosphate, and hydroxide up to 100 C. A variety of data are used, including isopiestic and electromotive force measurements, freezing point data, vapor pressure data at 100 C, heat capacities, heats of dilution, and solubility measurements. Pitzer's ion-interaction treatment is used to model electrolyte solutions, and many unknown parameters are determined from existing data through nonlinear least-squares fitting. Phase equilibria are determined by minimization of the total Gibbs energy using a modification of the code SOLGASMIX. Results calculated using the model accurately predict phase equilibria from many quantitative experiments. Qualitative experiments are performed to evaluate calculated solubilities in regions of sparse or nonexistent data; the calculated results are reasonable and exhibit a general qualitative agreement with such data. Model predictions are useful in understanding problems that may arise in the treatment of waste streams containing fluoride and phosphate anions in highly caustic solutions.

  3. A solubility model for aqueous solutions containing sodium, fluoride, and phosphate ions

    A significant problem in the processing of radioactive wastes is uncontrolled precipitation in solutions containing hydroxide, fluoride, and phosphate ions. A computational model is developed to calculate thermodynamic phase equilibria in aqueous solutions of fluoride, phosphate, and hydroxide up to 100 C. A variety of data are used, including isopiestic and electromotive force measurements, freezing point data, vapor pressure data at 100 C, heat capacities, heats of dilution, and solubility measurements. Pitzer's ion-interaction treatment is used to model electrolyte solutions, and many unknown parameters are determined from existing data through nonlinear least-squares fitting. Phase equilibria are determined by minimization of the total Gibbs energy using a modification of the code SOLGASMIX. Results calculated using the model accurately predict phase equilibria from many quantitative experiments. Qualitative experiments are performed to evaluate calculated solubilities in regions of sparse or nonexistent data; the calculated results are reasonable and exhibit a general qualitative agreement with such data. Model predictions are useful in understanding problems that may arise in the treatment of waste streams containing fluoride and phosphate anions in highly caustic solutions

  4. Red phosphorus oxidation by oxygen in alcohol solution of iodine and sodium nitrite

    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

  5. Determination of degraded products of TBP in the sodium carbonate waste solutions of PUREX process

    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

  6. Carbon-supported cobalt catalyst for hydrogen generation from alkaline sodium borohydride solution

    Xu, Dongyan; Liu, Xinmin; Cao, Changqing; Guo, Qingjie [College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Dai, Ping [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China)

    2008-08-01

    Low cost transition metal catalysts with high performance are attractive for the development of on-board hydrogen generation systems by catalytic hydrolysis of sodium borohydride (NaBH{sub 4}) in fuel cell fields. In this study, hydrogen production from alkaline NaBH{sub 4} via hydrolysis process over carbon-supported cobalt catalysts was studied. The catalytic activity of the supported cobalt catalyst was found to be highly dependent on the calcination temperatures. The hydrogen generation rate increases with calcination temperatures in the range of 200-400 C, but a high calcination temperature above 500 C led to markedly decreased activity. X-ray diffraction patterns reveal that the catalysts experience phase transition from amorphous Co-B to crystalline cobalt hydroxide with increase in calcination temperatures. The reaction performance is also dependent on the concentration of NaBH{sub 4}, and the hydrogen generation rate increases for lower NaBH{sub 4} concentrations and decreases after reaching a maximum at 10 wt.% of NaBH{sub 4}. (author)

  7. Fluorescence sensitization of gold-glutathione nanoclusters by aqueous solutions of sodium and potassium ions

    Gold nanoclusters (Au-NCs) are powerful alternatives to commonly used dyes for use in fluorescent assays and in imaging. This is due to their high brightness and biocompatibility. Glutathione protected gold nanoclusters (Au-NCs-GSH) were used to investigate the effect of sodium and potassium ions (at 0.1 to 1 mM concentrations) on their fluorescence. It was found that addition of these alkali ions does not modify the emission wavelength of AuNCs-GSH, but fluorescence intensity undergoes a gradual increase (by ∼130 %) until a plateau is reached. Fluorescence is particularly enhanced by KSCN. The effect is interpreted in terms of a decrease in the band gap of the AuNCs-GSH that depends on the nature of the anion. The results illustrate the role of anions and monovalent cations commonly used in buffers with respect to the tuning of the fluorescence of AuNCs-GSH. The findings should be taken into account when using AuNCs-GSH in assays based on fluorescence enhancement or quenching. (author)

  8. Measurements and modeling of deposition rates from a near supercritical aqueous sodium sulfate solution to a heated cylinder

    Toxic organic wastes and mixed wastes, composed of toxic organic compounds and radioactive elements, are a major environmental management problem. Supercritical water oxidation (SCWO) shows promise for effective remediation of these wastes by destroying their organic constituents and, when necessary, concentrating their radioactive ingredients in forms suited to safe disposal. In the Supercritical Water oxidation process, organic compounds containing heteroatoms such as S, Cl or P are oxidized to the corresponding acid. In order to avoid corrosion, bases are therefore often injected into the reactor. The salts that are formed upon neutralization (sulfates, chlorides, phosphates, etc.) have low solubility in SCW and consequently precipitate as solid phases. These salts can form agglomerates and coat internal surfaces, leading to plugging of transport lines and inhibition of heat transfer. The purpose of this study is to develop an understanding of salt deposition kinetics and nucleation phenomena in SCWO reactors. The authors provide experimental deposition rate data from a sodium sulfate-containing SCW stream to a heated cylinder and develop a predictive model which is buttressed by these data. They also discuss how the deposition rate is linked to the nucleation mechanism and what type of nucleation is most important in the experiments. For the experiments, the test section is a six-port chamber which is fashioned from a 1.91 cm (3/4 in.) diameter Swagelok cross. One port was used to mount a 5.08 mm diameter internally heated cylinder into the center of the chamber and the remaining ports provided fluid cross flow, visual observation capability and instrumentation access. Aqueous sodium sulfate solutions of 4 wt% salt concentration were pumped at about 250 bar through preheaters that brought the solution to a temperature close to that at which precipitation occurs. The heated cylinder raised the nearby solution above this temperature, thus limiting deposition almost exclusively to the heated cylinder. The rate of deposition was observed to be of order 0.1 gm/minute. Natural convection dominated transport at the conditions investigated and the observed deposition rates indicate that all the salt nucleated heterogeneously at the salt layer-solution interface

  9. Self-assembled monolayers formed by ammonium pyrrolidine dithiocarbamate on copper surfaces in sodium chloride solution

    Highlights: • Ammonium pyrrolidine dithiocarbamate is an efficient copper inhibitor. • Its maximum inhibition efficiency in a 3% NaCl solution can reach over 98%. • The two sulfur atoms of the inhibitor are the most active adsorption sites. - Abstract: The inhibiting effect of ammonium pyrrolidine dithiocarbamate (APDTC) self-assembled monolayers (SAMs) on the corrosion of copper surface in a 3 wt.% NaCl solution is reported using electrochemical methods, surface analysis and theoretical studies. The optimum conditions for formation of SAMs established using impedance studies are 1 mmol L−1 concentration of APDTC and an immersion period of 8 h and its maximum inhibition efficiency could reach 98.7%. Infrared spectrum and energy dispersive spectroscopy analyses all show that APDTC is adsorbed on the copper surface and quantum chemical calculation results reveal that the sulfur atoms are the most active adsorption sites

  10. Electrochemical Study of Corrosion Behavior of Wrought Stellite Alloys in Sodium Chloride and Green Death Solutions

    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.

  11. Effects of applied potential on the fatigue behavior of Alloy 600 in sodium chloride solution

    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

  12. Rupture of mild steel passivity to carbon in neutral solutions containing sodium sulfate

    The localized corrosion of mild steel in neutral buffered solutions containing Na2SO4 was studied using potentiostatic and potentiodynamic techniques complemented by scanning electron microscopy. The breakdown potential depends linearly on the logarithm of Na2SO4 concentration. The logarithm of the induction time for pitting initiation decreases linearly with the reciprocal of the applied potential until the inhibition potential region is reached. Open scircuit potential decay, measured during the induction time, shows that the apparent thickness of the passive oxide film decreases before pit growth. The pitting current density is close to the diffusion limiting current of iron dissolution through a FeSO4 film. Results suggest that two dimensional ferrous sulfate salt islands are formed before pitting, as it has been postulated for iron in halide containing solutions. (C.L.B.)

  13. Sodium Tetraethylenepentamine Heptaacetate as Novel Draw Solute for Forward Osmosis—Synthesis, Application and Recovery

    Qing Wu Long; Yan Wang

    2015-01-01

    Osmotic energy, as a sustainable energy source with little environmental impact, has drawn much attention in both academia and industry in recent years. Osmotically driven membrane processes can harvest the osmotic energy and thus have great potential to produce sustainable clean water or electric energy. The draw solution, as an osmotic component, has been more and more explored by scientists in recent years in order to achieve a high osmotic pressure and suitable molecular size. In this wor...

  14. Sodium chloride crystallization from drying drops of albumin-salt solutions with different albumin concentrations

    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.

  15. Saturated sodium chloride solution under an external static electric field: A molecular dynamics study

    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. Localized corrosion of nickel-based steam generator tubing alloys in sodium sulfate solutions containing thiosulfate

    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)

  17. Mathematic modelling of kinetics for the crystallization of tungstic acid from electrolytically treated sodium tungstate solution

    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

  18. Effect of sodium phosphate salts on the thermodynamic properties of aqueous solutions of poly(ethylene oxide) 6000 at different temperatures

    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

    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. Phase formation in zirconium sulfate solutions in the presence of sodium fluorides

    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

  1. Inefficacy of osmotic backwash induced by sodium chloride salt solution in controlling SWRO membrane fouling

    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.

  2. Mono Azo Dyes Compounds as Corrosion Inhibitors for Dissolution of Aluminium in Sodium Hydroxide Solutions

    Salih S. Al-Juaid

    2007-01-01

    Full Text Available The effect of some mono azo dyes compounds on the dissolution of aluminium in 0.01 M NaOH solutions was studied using weight loss and galvanostatic polarization techniques. The percentage inhibition efficiency was found to increase with increasing concentration of inhibitor and with decreasing temperature. The inhibition mechanism was discussed on the basis of the formation of complex compound adsorbed on the metal surface. The adsorption process follows Frumkin isotherm. The effect of temperature on the rate of corrosion in the absence and presence of these compounds was also studied. Some activated thermodynamic parameters were computed.

  3. Solubility of NaNd(CO3)2.6H2O(c) in concentrated Na2CO3 and NaHCO3 solutions

    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.)

  4. Dispersion effect of sodium hexametaphosphate on the photocatalytic efficiency of a solution-combusted ZnO nanopowder

    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.

  5. Standard practice for exposure of metals and alloys by alternate immersion in neutral 3.5% Sodium Chloride solution

    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. ...

  6. Mechanism of immersion deposition of Ni-P films on Si(100) in an aqueous alkaline solution containing sodium hypophosphite

    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.

  7. Modelling the process of Al(OH3 crystallization from industrial sodium aluminate solutions using artificial neural networks

    ŽIVAN ŽIVKOVIĆ

    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. Differential proteomics to explore the inhibitory effects of acidic, slightly acidic electrolysed water and sodium hypochlorite solution on Vibrio parahaemolyticus.

    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

  9. -Saturated Solutions

    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.

  10. Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy

    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.

  11. Investigation of the corrosion of pure magnesium in aerated sodium sulfate solutions

    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. Polarographic study of electroreduction kinetics of molybdenum(6) complexes in acid solutions of sodium sulfate

    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

  13. Corrosion Behavior of Stainless Steels in Neutral and Acidified Sodium Chloride Solutions by Electrochemical Impedance Spectroscopy

    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.

  14. Pulse radiolysis of aqueous solutions of sodium azide: reactions of azide radical with tryptophan and tyrosine

    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)

  15. Solubilities of betulin and betulinic acid in sodium hydroxide aqueous solutions of varied mole fraction at temperatures from 283.2 K to 323.2 K

    Highlights: • The solubilities of betulin and betulinic acid in varied mole fraction of sodium hydroxide aqueous solutions. • The experimental solubility data are correlated by Apelblat equation. • The dissolution enthalpy and entropy were calculated using van’t Hoff equation. -- Abstract: The solubilities of betulin and betulinic acid were measured at varied values of mole fraction of sodium hydroxide aqueous solutions at a series of temperature (283.2, 293.2, 303.2, 313.2, and 323.2) K. They increase with the increase of temperature. Furthermore, the solubility of betulinic acid has a positive correlation with the mole fraction of sodium hydroxide aqueous solutions, and so is that of the betulin. The experimental solubility resuls are well correlated by the modified Apelblat equation. The enthalpy and entropy of betulin and betulinic acid during the dissolution process in sodium hydroxide aqueous solutions are calculated with the van’t Hoff equation. The results indicate that the dissolution process is endothermal reaction that is driven by entropy

  16. SiO2-supported ferromagnetic catalysts for hydrogen generation from alkaline NaBH4 (sodium borohydride) solution

    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

  17. Real surface area of the aluminium electrode in sodium chloride solution

    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.

  18. Pulse radiolysis study of reaction intermediates in aqueous solutions of sodium tetraphenylborate

    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

  19. Clarification of sodium silicate solutions derived from diatomites, to improve their industrial expectations

    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)

  20. Correcting Acidosis during Hemodialysis: Current Limitations and a Potential Solution.

    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