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Sample records for alkaline peptone water

  1. Nonthermal inactivation of Escherichia coli K12 in buffered peptone water using a pilot-plant scale supercritical carbon dioxide system with gas-liquid porous metal contractor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the effectiveness of a supercritical carbon dioxide (SCCO2) system, with a gas-liquid CO2 contactor, for reducing Escherichia coli K12 in diluted buffered peptone water. 0.1% (w/v) buffered peptone water inoculated with E. coli K12 was processed using the SCCO2 system at CO2 con...

  2. Advanced alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Wakabayashi, N.; Torikai, E.; Kawami, Y.; Takenaka, H.

    Results are presented of experimental studies of possible separators and electrodes for use in advanced, high-temperature, high-pressure alkaline water electrolyzers. Material evaluations in alkaline water electrolyzers at temperatures from 100 to 120 C have shown a new type polytetrafluoroethylene membrane impregnated with potassium titanate to be the most promising when the separator is prepared by the hydrothermal treatment of a porous PFTE membrane impregnated with hydrated titanium oxide. Measurements of cell voltages in 30% KOH at current densities from 5 to 100 A/sq dm at temperatures up to 120 C with nickel electrodes of various structures have shown the foamed nickel electrode, with an average pore size of 1-1.5 mm, to have the best performance. When the foamed nickel is coated by fine powdered nickel, carbonyl nickel or Raney nickel to increase electrode surface areas, even lower cell voltages were found, indicating better performance.

  3. Application of low frequency pulsed ohmic heating for inactivation of foodborne pathogens and MS-2 phage in buffered peptone water and tomato juice.

    PubMed

    Kim, Sang-Soon; Choi, Won; Kang, Dong-Hyun

    2017-05-01

    The purpose of this study was to inactivate foodborne pathogens effectively by ohmic heating in buffered peptone water and tomato juice without causing electrode corrosion and quality degradation. Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes were used as representative foodborne pathogens and MS-2 phage was used as a norovirus surrogate. Buffered peptone water and tomato juice inoculated with pathogens were treated with pulsed ohmic heating at different frequencies (0.06-1 kHz). Propidium iodide uptake values of bacterial pathogens were significantly (p < 0.05) larger at 0.06-0.5 kHz than at 1 kHz, and sub-lethal injury of pathogenic bacteria was reduced by decreasing frequency. MS-2 phage was inactivated more effectively at low frequency, and was more sensitive to acidic conditions than pathogenic bacteria. Electrode corrosion and quality degradation of tomato juice were not observed regardless of frequency. This study suggests that low frequency pulsed ohmic heating is applicable to inactivate foodborne pathogens effectively without causing electrode corrosion and quality degradation in tomato juice.

  4. Alkaline Water and Longevity: A Murine Study

    PubMed Central

    Magro, Massimiliano; Corain, Livio; Ferro, Silvia; Baratella, Davide; Bonaiuto, Emanuela; Terzo, Milo; Corraducci, Vittorino; Salmaso, Luigi; Vianello, Fabio

    2016-01-01

    The biological effect of alkaline water consumption is object of controversy. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model. Starting from the second year of life, nonparametric survival plots suggest that mice watered with alkaline water showed a better survival than control mice. Interestingly, statistical analysis revealed that alkaline water provides higher longevity in terms of “deceleration aging factor” as it increases the survival functions when compared with control group; namely, animals belonging to the population treated with alkaline water resulted in a longer lifespan. Histological examination of mice kidneys, intestine, heart, liver, and brain revealed that no significant differences emerged among the three groups indicating that no specific pathology resulted correlated with the consumption of alkaline water. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water of long-lived mouse models. PMID:27340414

  5. Comparison of rose bengal-chloramphenicol and modified aureomycin-rose bengal-glucose-peptone agar as media for the enumeration of molds and yeasts in water by membrane filtration techniques.

    PubMed

    Albaum, Silva; Masaphy, Segula

    2009-03-01

    The present study compares the suitability of rose bengalchloramphenicol (RBCh) and modified aureomycin-rose bengal glucose-peptone agar for enumerating fungi recovered from diverse water sources using the membrane filtration method. Both mold and yeast colonies were established more rapidly, with more intensified colony colors and higher RBCh counts.

  6. 21 CFR 184.1553 - Peptones.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....1553 Peptones. (a) Peptones are a variable mixture of polypeptides, oligopeptides, and amino acids that... paragraph with safe and suitable acids or heat. (b) The ingredients must be of a purity suitable for...

  7. Copper release in low and high alkaline water.

    PubMed

    D'Antonio, L; Fabbricino, M; Nasso, M; Trifuoggi, M

    2008-04-01

    Copper release in drinking water, caused by electrochemical corrosion of household distribution systems, was investigated. Experiments were developed testing both low and high alkaline water in stagnant conditions. The effect of varying stagnation time was investigated also. Both soluble and insoluble copper compounds, produced by corrosion processes are quantified, using appropriate experimental procedures. On the basis of obtained results, copper concentration in stagnant water is defined as a function of water alkalinity, while total metal release is defined as a function of stagnation length, and is not dependent on water alkalinity.

  8. Advanced alkaline water electrolysis. Task 2 summary report. Model for alkaline water electrolysis systems

    SciTech Connect

    Yaffe, M.R.; Murray, J.N.

    1980-04-01

    Task 2 involved the establishment of an engineering and economic model for the evaluation of various options in water electrolysis. The mode, verification of the specific coding and four case studies are described. The model was tested by evaluation of a nearly commercial technology, i.e., an 80-kW alkaline electrolyte system, operating at 60/sup 0/C, which delivers approximately 255 SLM, hydrogen for applications such as electrical generation cooling or semiconductor manufacturing. The calculated cost of hydrogen from this installed non-optimized case system with an initial cost to the customer of $87,000 was $6.99/Kg H/sub 2/ ($1.67/100 SCF) on a 20-yr levelized basis using 2.5 cents/kWh power costs. This compares favorably to a levelized average merchant hydrogen cost value of $9.11/Kg H/sub 2/ ($2.17/100 SCF) calculated using the same program.

  9. Thermal Inactivation of Infectious Pancreatic Necrosis Virus in a Peptone-Salt Medium Mimicking the Water-Soluble Phase of Hydrolyzed Fish By-Products

    PubMed Central

    Modahl, Ingebjørg; Myrmel, Mette

    2012-01-01

    Infectious pancreatic necrosis virus (IPNV) (serotype Sp) was exposed to temperatures between 60 and 90°C in a medium mimicking the water-soluble phase of hydrolyzed fish by-products. D values ranged from 290 to 0.5 min, and the z value was approximately 9.8°C. Addition of formic acid to create a pH 4 medium did not enhance heat inactivation. Predicted inactivation effects at different temperature-time combinations are provided. PMID:22247167

  10. Endurance test and evaluation of alkaline water electrolysis cells

    NASA Technical Reports Server (NTRS)

    Burke, K. A.; Schubert, F. H.

    1981-01-01

    Utilization in the development of multi-kW low orbit power systems is discussed. The following technological developments of alkaline water electrolysis cells for space power application were demonstrated: (1) four 92.9 cm2 single water electrolysis cells, two using LST's advanced anodes and two using LST's super anodes; (2) four single cell endurance test stands for life testing of alkaline water electrolyte cells; (3) the solid performance of the advanced electrode and 355 K; (4) the breakthrough performance of the super electrode; (5) the four single cells for over 5,000 hours each significant cell deterioration or cell failure. It is concluded that the static feed water electrolysis concept is reliable and due to the inherent simplicity of the passive water feed mechanism coupled with the use of alkaline electrolyte has greater potential for regenerative fuel cell system applications than alternative electrolyzers. A rise in cell voltage occur after 2,000-3,000 hours which was attributed to deflection of the polysulfone end plates due to creepage of the thermoplastic. More end plate support was added, and the performance of the cells was restored to the initial performance level.

  11. Endurance test and evaluation of alkaline water electrolysis cells

    NASA Astrophysics Data System (ADS)

    Burke, K. A.; Schubert, F. H.

    1981-11-01

    Utilization in the development of multi-kW low orbit power systems is discussed. The following technological developments of alkaline water electrolysis cells for space power application were demonstrated: (1) four 92.9 cm2 single water electrolysis cells, two using LST's advanced anodes and two using LST's super anodes; (2) four single cell endurance test stands for life testing of alkaline water electrolyte cells; (3) the solid performance of the advanced electrode and 355 K; (4) the breakthrough performance of the super electrode; (5) the four single cells for over 5,000 hours each significant cell deterioration or cell failure. It is concluded that the static feed water electrolysis concept is reliable and due to the inherent simplicity of the passive water feed mechanism coupled with the use of alkaline electrolyte has greater potential for regenerative fuel cell system applications than alternative electrolyzers. A rise in cell voltage occur after 2,000-3,000 hours which was attributed to deflection of the polysulfone end plates due to creepage of the thermoplastic. More end plate support was added, and the performance of the cells was restored to the initial performance level.

  12. Effect of electropermeabilization by ohmic heating for inactivation of Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes in buffered peptone water and apple juice.

    PubMed

    Park, Il-Kyu; Kang, Dong-Hyun

    2013-12-01

    The effect of electric field-induced ohmic heating for inactivation of Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes in buffered peptone water (BPW) (pH 7.2) and apple juice (pH 3.5; 11.8 °Brix) was investigated in this study. BPW and apple juice were treated at different temperatures (55°C, 58°C, and 60°C) and for different times (0, 10, 20, 25, and 30 s) by ohmic heating compared with conventional heating. The electric field strength was fixed at 30 V/cm and 60 V/cm for BPW and apple juice, respectively. Bacterial reduction resulting from ohmic heating was significantly different (P<0.05) from that resulting from conventional heating at 58°C and 60°C in BPW and at 55°C, 58°C, and 60°C in apple juice for intervals of 0, 10, 20, 25, and 30 s. These results show that electric field-induced ohmic heating led to additional bacterial inactivation at sublethal temperatures. Transmission electron microscopy (TEM) observations and the propidium iodide (PI) uptake test were conducted after treatment at 60°C for 0, 10, 20, 25 and 30 s in BPW to observe the effects on cell permeability due to electroporation-caused cell damage. PI values when ohmic and conventional heating were compared were significantly different (P<0.05), and these differences increased with increasing levels of inactivation of three food-borne pathogens. These results demonstrate that ohmic heating can more effectively reduce bacterial populations at reduced temperatures and shorter time intervals, especially in acidic fruit juices such as apple juice. Therefore, loss of quality can be minimized in a pasteurization process incorporating ohmic heating.

  13. Effect of Electropermeabilization by Ohmic Heating for Inactivation of Escherichia coli O157:H7, Salmonella enterica Serovar Typhimurium, and Listeria monocytogenes in Buffered Peptone Water and Apple Juice

    PubMed Central

    Park, Il-Kyu

    2013-01-01

    The effect of electric field-induced ohmic heating for inactivation of Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes in buffered peptone water (BPW) (pH 7.2) and apple juice (pH 3.5; 11.8 °Brix) was investigated in this study. BPW and apple juice were treated at different temperatures (55°C, 58°C, and 60°C) and for different times (0, 10, 20, 25, and 30 s) by ohmic heating compared with conventional heating. The electric field strength was fixed at 30 V/cm and 60 V/cm for BPW and apple juice, respectively. Bacterial reduction resulting from ohmic heating was significantly different (P < 0.05) from that resulting from conventional heating at 58°C and 60°C in BPW and at 55°C, 58°C, and 60°C in apple juice for intervals of 0, 10, 20, 25, and 30 s. These results show that electric field-induced ohmic heating led to additional bacterial inactivation at sublethal temperatures. Transmission electron microscopy (TEM) observations and the propidium iodide (PI) uptake test were conducted after treatment at 60°C for 0, 10, 20, 25 and 30 s in BPW to observe the effects on cell permeability due to electroporation-caused cell damage. PI values when ohmic and conventional heating were compared were significantly different (P < 0.05), and these differences increased with increasing levels of inactivation of three food-borne pathogens. These results demonstrate that ohmic heating can more effectively reduce bacterial populations at reduced temperatures and shorter time intervals, especially in acidic fruit juices such as apple juice. Therefore, loss of quality can be minimized in a pasteurization process incorporating ohmic heating. PMID:23995939

  14. Endurance Test and Evaluation of Alkaline Water Electrolysis Cells

    NASA Technical Reports Server (NTRS)

    Kovach, Andrew J.; Schubert, Franz H.; Chang, B. J.; Larkins, Jim T.

    1985-01-01

    The overall objective of this program is to assess the state of alkaline water electrolysis cell technology and its potential as part of a Regenerative Fuel Cell System (RFCS) of a multikilowatt orbiting powerplant. The program evaluates the endurance capabilities of alkaline electrolyte water electrolysis cells under various operating conditions, including constant condition testing, cyclic testing and high pressure testing. The RFCS demanded the scale-up of existing cell hardware from 0.1 sq ft active electrode area to 1.0 sq ft active electrode area. A single water electrolysis cell and two six-cell modules of 1.0 sq ft active electrode area were designed and fabricated. The two six-cell 1.0 sq ft modules incorporate 1.0 sq ft utilized cores, which allow for minimization of module assembly complexity and increased tolerance to pressure differential. A water electrolysis subsystem was designed and fabricated to allow testing of the six-cell modules. After completing checkout, shakedown, design verification and parametric testing, a module was incorporated into the Regenerative Fuel Cell System Breadboard (RFCSB) for testing at Life Systems, Inc., and at NASA JSC.

  15. Recent developments on IME-alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Vandenborre, H.; Baetsle, L. H.; Hebel, W.; Leysen, R.; Nackaerts, H.; Spaepen, G.

    Demonstration on a laboratory scale is reported for the substitution of the conventional asbestos diaphragm in alkaline water electrolysis processes by thin sheets of polyantimonic acid and polysulfone. The membranes investigated withstand concentrated KOH solutions at up to 120 C, and have the necessary ion-conducting and gas-separating properties. It was also found that, by increasing the amount of polyantimonic acid in the membrane, electrolyte concentration can be lowered from 30 percent to 5 percent (by weight) without major effect on the cell voltage.

  16. Solid-State Water Electrolysis with an Alkaline Membrane

    SciTech Connect

    Leng, YJ; Chen, G; Mendoza, AJ; Tighe, TB; Hickner, MA; Wang, CY

    2012-06-06

    We report high-performance, durable alkaline membrane water electrolysis in a solid-state cell. An anion exchange membrane (AEM) and catalyst layer ionomer for hydroxide ion conduction were used without the addition of liquid electrolyte. At 50 degrees C, an AEM electrolysis cell using iridium oxide as the anode catalyst and Pt black as the cathode catalyst exhibited a current density of 399 mA/cm(2) at 1.80 V. We found that the durability of the AEM-based electrolysis cell could be improved by incorporating a highly durable ionomer in the catalyst layer and optimizing the water feed configuration. We demonstrated an AEM-based electrolysis cell with a lifetime of > 535 h. These first-time results of water electrolysis in a solid-state membrane cell are promising for low-cost, scalable hydrogen production.

  17. Growth of Campylobacter Incubated Aerobically in Media Supplemented with Peptones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growth of Campylobacter cultures incubated aerobically in media supplemented with peptones was studied, and additional experiments were conducted to compare growth of the bacteria in media supplemented with peptones to growth in media supplemented with fumarate-pyruvate-minerals-vitamins (FPMV). A b...

  18. SIMPLE WAYS TO IMPROVE PH AND ALKALINITY MEASUREMENTS FOR WATER UTILITIES AND LABORATORIES

    EPA Science Inventory

    Both pH and total alkalinity determinations are critical in characterizing chemical properties of water, being important to implementing good process control, determining corrosivity and other water quality properties, and assessing changes in water characteristics. Poor charac...

  19. [Risks associated with unrestricted consumption of alkaline-reduced water].

    PubMed

    Henry, Marc; Chambron, Jacques

    2014-01-01

    Consumption of alkaline reduced water produced by domestic electrolysis devices was approved in Japan in 1965 by the Minister of Health, Work and Wellbeing, for the treatment of gastrointestinal disorders. Today, these devices are also freely available in France. The commercial information provided with the devices recommends the consumption of 1 to 1.5 liters per day, not only for gastrointestinal disorders but also for numerous other illnesses such as diabetes, cancer and inflammation. Academic research on this subject has been undergoing in Japan since 1990, and has established that the active ingredient is dissolved dihydrogen, which eliminates the free radical HO· in vivo. It has also been shown that electrode degradation during use of the devices releases highly reactive platinum nanoparticles, the toxicity of which is unknown. The authors of this report recommend alerting the French health authorities to the uncontrolled availability of these devices that generate drug substances and should therefore be subject to regulatory requirements.

  20. Belliella buryatensis sp. nov., isolated from alkaline lake water.

    PubMed

    Kozyreva, Lyudmila; Egorova, Darya; Anan'ina, Lyudmila; Plotnikova, Elena; Ariskina, Elena; Prisyazhnaya, Natalya; Radnaeva, Larisa; Namsaraev, Bair

    2016-01-01

    Two bacterial isolates from water of the alkaline brackish Lake Solenoe (Buryatia, Russia), 2C and 5CT, were characterized by using a polyphasic taxonomic approach. The strains were small, non-motile, Gram-stain-negative rods that formed small orange-red colonies on the surface of marine agar. Studies based on 16S rRNA gene sequences showed that the strains were related closely to Belliella pelovolcani CC-SAL-25T (98.7 % sequence similarity). The G+C content of the DNA was 38-40 mol%. DNA-DNA hybridization values between strains 2C and 5CT and B. pelovolcani CC-SAL-25T were 56-58 mol%. A menaquinone with seven isoprene units (MK-7) was the major respiratory quinone. The fatty acid profiles were slightly different from that of B. pelovolcani CC-SAL-25T. The novel strains could be distinguished from the phylogenetically closest species B. pelovolcani CC-SAL-25T based on matrix-assisted laser desorption ionization time-of-flight mass spectra of whole cells and a range of physiological and biochemical characteristics. The data obtained suggest that strains 2C and 5CT represent a novel species of the genus Belliella, for which the name Belliella buryatensis sp. nov. is proposed. The type strain is 5CT ( = VKM B-2724T = KCTC 32194T).

  1. Ionized alkaline water: new strategy for management of metabolic acidosis in experimental animals.

    PubMed

    Abol-Enein, Hassan; Gheith, Osama A; Barakat, Nashwa; Nour, Eman; Sharaf, Abd-Elhameed

    2009-06-01

    Metabolic acidosis can occur as a result of either the accumulation of endogenous acids or loss of bicarbonate from the gastrointestinal tract or the kidney, which represent common causes of metabolic acidosis. The appropriate treatment of acute metabolic acidosis has been very controversial. Ionized alkaline water was not evaluated in such groups of patients in spite of its safety and reported benefits. So, we aimed to assess its efficacy in the management of metabolic acidosis in animal models. Two models of metabolic acidosis were created in dogs and rats. The first model of renal failure was induced by ligation of both ureters; and the second model was induced by urinary diversion to gut (gastrointestinal bicarbonate loss model). Both models were subjected to ionized alkaline water (orally and by hemodialysis). Dogs with renal failure were assigned to two groups according to the type of dialysate utilized during hemodialysis sessions, the first was utilizing alkaline water and the second was utilizing conventional water. Another two groups of animals with urinary diversion were arranged to receive oral alkaline water and tap water. In renal failure animal models, acid-base parameters improved significantly after hemodialysis with ionized alkaline water compared with the conventional water treated with reverse osmosis (RO). Similar results were observed in urinary diversion models as there was significant improvement of both the partial pressure of carbon dioxide and serum bicarbonate (P = 0.007 and 0.001 respectively) after utilizing alkaline water orally. Alkaline ionized water can be considered as a major safe strategy in the management of metabolic acidosis secondary to renal failure or dialysis or urinary diversion. Human studies are indicated in the near future to confirm this issue in humans.

  2. Cultivation of marine shrimp in biofloc technology (BFT) system under different water alkalinities.

    PubMed

    Piérri, V; Valter-Severino, D; Goulart-de-Oliveira, K; Manoel-do-Espírito-Santo, C; Nascimento-Vieira, F; Quadros-Seiffert, W

    2015-08-01

    The aim of this study was to evaluate the influence of different levels of alkalinity for the superintensive cultivation of marine shrimp Litopenaeus vannamei in biofloc system. A total of 12 experimental circular units of 1000L were used supplied with 850L water from a nursery, populated at a density of 165 shrimps.m-3 and average weight of 5.6 g. The treatments, in triplicate, consisted in four levels of alkalinity in the water: 40, 80, 120 and 160 mg.L-1 of calcium carbonate. To correct the alkalinity was used calcium hydroxide (CaOH). It was observed a decrease in pH of the water in the treatments with lower alkalinity (p<0.05). The total suspended settleable solids were also lower in the treatment of low alkalinity. No significant difference was observed in other physico-chemical and biological parameters in the water quality assessed, as well as the zootechnical parameters of cultivation between treatments (p≥0.05). The results of survival and growth rate of shrimps were considered suitable for the cultivation system used in the different treatments. The cultivation of marine shrimp Litopenaeus vannamei in biofloc at density of 165 shrimps.m-3 can be performed in waters with alkalinity between 40 and 160 mg.L-1 of CaCO3, without compromising the zootechnical indexes of cultivation.

  3. Systemic and local effects of long-term exposure to alkaline drinking water in rats.

    PubMed

    Merne, M E; Syrjänen, K J; Syrjänen, S M

    2001-08-01

    Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water or bicarbonate toothpaste. The effects of alkaline pH on oral mucosa have not been systematically studied. To assess the systemic (organ) and local (oral mucosal) effects of alkalinity, drinking water supplemented with Ca(OH)2 or NaOH, with pH 11.2 or 12 was administered to rats (n = 36) for 52 weeks. Tissues were subjected to histopathological examination; oral mucosal biopsy samples were also subjected to immunohistochemical (IHC) analyses for pankeratin, CK19, CK5, CK4, PCNA, ICAM-1, CD44, CD68, S-100, HSP 60, HSP70, and HSP90. At completion of the study, animals in the study groups had lower body weights (up to 29% less) than controls despite equal food and water intake, suggesting a systemic response to the alkaline treatment. The lowest body weight was found in rats exposed to water with the highest pH value and starting the experiment when young (6 weeks). No histological changes attributable to alkaline exposure occurred in the oral mucosa or other tissues studied. Alkaline exposure did not affect cell proliferation in the oral epithelium, as shown by the equal expression of PCNA in groups. The up-regulation of HSP70 protein expression in the oral mucosa of rats exposed to alkaline water, especially Ca(OH)2 treated rats, may indicate a protective response. Intercellular adhesion molecule-1 (ICAM-1) positivity was lost in 6/12 rats treated with Ca(OH)2 with pH 11.2, and loss of CD44 expression was seen in 3/6 rats in both study groups exposed to alkaline water with pH 12. The results suggest that the oral mucosa in rats is resistant to the effects of highly alkaline drinking water. However, high alkalinity may have some unknown systemic effects leading to growth retardation, the cause of which remains to be determined.

  4. Systemic and local effects of long-term exposure to alkaline drinking water in rats

    PubMed Central

    Merne, Marina ET; Syrjänen, Kari J; Syrjänen, Stina M

    2001-01-01

    Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water or bicarbonate toothpaste. The effects of alkaline pH on oral mucosa have not been systematically studied. To assess the systemic (organ) and local (oral mucosal) effects of alkalinity, drinking water supplemented with Ca(OH)2 or NaOH, with pH 11.2 or 12 was administered to rats (n = 36) for 52 weeks. Tissues were subjected to histopathological examination; oral mucosal biopsy samples were also subjected to immunohistochemical (IHC) analyses for pankeratin, CK19, CK5, CK4, PCNA, ICAM-1, CD44, CD68, S-100, HSP 60, HSP70, and HSP90. At completion of the study, animals in the study groups had lower body weights (up to 29% less) than controls despite equal food and water intake, suggesting a systemic response to the alkaline treatment. The lowest body weight was found in rats exposed to water with the highest pH value and starting the experiment when young (6 weeks). No histological changes attributable to alkaline exposure occurred in the oral mucosa or other tissues studied. Alkaline exposure did not affect cell proliferation in the oral epithelium, as shown by the equal expression of PCNA in groups. The up-regulation of HSP70 protein expression in the oral mucosa of rats exposed to alkaline water, especially Ca(OH)2 treated rats, may indicate a protective response. Intercellular adhesion molecule-1 (ICAM-1) positivity was lost in 6/12 rats treated with Ca(OH)2 with pH 11.2, and loss of CD44 expression was seen in 3/6 rats in both study groups exposed to alkaline water with pH 12. The results suggest that the oral mucosa in rats is resistant to the effects of highly alkaline drinking water. However, high alkalinity may have some unknown systemic effects leading to growth retardation, the cause of which remains to be determined. PMID:11493345

  5. Redistribution of wastewater alkalinity with a microbial fuel cell to support nitrification of reject water.

    PubMed

    Modin, Oskar; Fukushi, Kensuke; Rabaey, Korneel; Rozendal, René A; Yamamoto, Kazuo

    2011-04-01

    In wastewater treatment plants, the reject water from the sludge treatment processes typically contains high ammonium concentrations, which constitute a significant internal nitrogen load in the plant. Often, a separate nitrification reactor is used to treat the reject water before it is fed back into the plant. The nitrification reaction consumes alkalinity, which has to be replenished by dosing e.g. NaOH or Ca(OH)(2). In this study, we investigated the use of a two-compartment microbial fuel cell (MFC) to redistribute alkalinity from influent wastewater to support nitrification of reject water. In an MFC, alkalinity is consumed in the anode compartment and produced in the cathode compartment. We use this phenomenon and the fact that the influent wastewater flow is many times larger than the reject water flow to transfer alkalinity from the influent wastewater to the reject water. In a laboratory-scale system, ammonium oxidation of synthetic reject water passed through the cathode chamber of an MFC, increased from 73.8 ± 8.9 mgN/L under open-circuit conditions to 160.1 ± 4.8 mgN/L when a current of 1.96 ± 0.37 mA (15.1 mA/L total MFC liquid volume) was flowing through the MFC. These results demonstrated the positive effect of an MFC on ammonium oxidation of alkalinity-limited reject water.

  6. Alkaline phosphatase activity of Escherichia coli starved in sterile lake water microcosms.

    PubMed

    Ozkanca, R; Flint, K P

    1996-03-01

    Escherichia coli grown in high or low phosphate medium was inoculated into a lake water starvation medium. The viable count decreased at 37 degrees C but not at the lower temperatures over 70 d. Alkaline phosphatase was monitored using a colorimetric assay with pNPP as the substrate. Derepression of the enzyme occurred in cultures starved for > 30 d in the lake water and within 5 d in lake water microcosms supplemented with carbon and nitrogen sources where there was rarely an increase in viable count. Chloramphenicol prevented the synthesis of alkaline phosphatase suggesting that, even under starvation conditions, de novo synthesis of the enzyme occurs.

  7. Pore water chemistry of an alkaline rift valley lake: Lake Turkana, Kenya

    SciTech Connect

    Cerling, T.E.; Johnson, T.C.; Halfman, J.D.; Lister, G.

    1985-01-01

    Lake Turkana is the largest closed basin lake in the African rift system. It has evolved through the past 5000 years to become a moderately alkaline lake. Previous mass balance argument suggest that sulfate is removed from the lake by sulfate reduction in the sediments, and that the lake is accumulating in chloride, sodium, and alkalinity. Studies of pore water from 12 meter cores collected in November 1984 show that sulfate is reduced in the sediment column with a net production of alkalinity. Some sodium is lost from the lake and diffuses into the sediment to maintain charge balance. At several meters depth, organic matter is destroyed by methanogenic bacteria, as shown by the high delta /sup 13/C values for dissolved inorganic carbon. Magnesium and calcium molar ratios change with depth; chloride, sodium, and alkalinity also change with depth.

  8. Influence of peptone source on sporulation of Clostridium perfringens type A.

    PubMed

    Hsieh, P Y; Labbe, R

    2007-07-01

    Clostridium perfringens is a foodborne disease agent that produces a sporulation-specific enterotoxin. To produce enterotoxin for experimental purposes or spores for challenge or physiological studies, the use of a convenient sporulation medium is required. The most commonly used is Duncan-Strong medium. Few isolates sporulate at high levels in this medium. We investigated the effectiveness of peptones from a variety of sources on the sporulation of this organism compared with the peptone in the original formulation, proteose peptone (control). Seven strains were used to screen 32 peptones, with starch or raffinose as the carbohydrate source. In most cases, raffinose was more effective than starch in stimulating sporulation, confirming our previous study. Two promising peptones, potato peptone, and Proteose Peptone no. 3, were selected and tested against 49 additional enterotoxin-positive and -negative strains, with raffinose as the carbohydrate. For 49 strains, 5 sporulated best (>10%) in the control peptone, 6 sporulated best in Peptone no. 3, and 23 sporulated best in the potato peptone. Of the 23 strains, 16 sporulated at levels 25% more than the control peptone. The increase in sporulation rates was reflected in the enterotoxin and heat-resistant spore levels. The methylxanthines caffeine and theobromine were effective in increasing the sporulation of less than half of 19 enterotoxin-positive strains. Our results suggest that the replacement of proteose peptone with potato peptone be considered if difficulty in obtaining spores of specific strains of C. perfringens is encountered.

  9. Rapid changes in water hardness and alkalinity: Calcite formation is lethal to Daphnia magna.

    PubMed

    Bogart, Sarah J; Woodman, Samuel; Steinkey, Dylan; Meays, Cindy; Pyle, Greg G

    2016-07-15

    There is growing concern that freshwater ecosystems may be negatively affected by ever-increasing anthropogenic inputs of extremely hard, highly alkaline effluent containing large quantities of Ca(2+), Mg(2+), CO3(2-), and HCO3(-) ions. In this study, the toxicity of rapid and extreme shifts in water hardness (38-600mg/L as CaCO3) and alkalinity (30-420mg/L as CaCO3) to Daphnia magna was tested, both independently and in combination. Within these ranges, where no precipitation event occurred, shifts in water hardness and/or alkalinity were not toxic to D. magna. In contrast, 98-100% of D. magna died within 96h after exposure to 600mg/L as CaCO3 water hardness and 420mg/L as CaCO3 alkalinity (LT50 of 60h with a 95% CI of 54.2-66.0h). In this treatment, a CaCO3 (calcite) precipitate formed in the water column which was ingested by and thoroughly coated the D. magna. Calcite collected from a mining impacted stream contained embedded organisms, suggesting field streams may also experience similar conditions and possibly increased mortality as observed in the lab tests. Although further investigation is required to determine the exact fate of aquatic organisms exposed to rapid calcite precipitation in the field, we caution that negative effects may occur more quickly or at lower concentrations of water hardness and alkalinity in which we observed effects in D. magna, because some species, such as aquatic insects, are more sensitive than cladocerans to changes in ionic strength. Our results provide evidence that both calcite precipitation and the major ion balance of waters should be managed in industrially affected ecosystems and we support the development of a hardness+alkalinity guideline for the protection of aquatic life.

  10. Evaluation of alkaline electrolyzed water to replace traditional phosphate enhancement solutions: Effects on water holding capacity, tenderness, and sensory characteristics.

    PubMed

    Rigdon, Macc; Hung, Yen-Con; Stelzleni, Alexander M

    2017-01-01

    Sixty-four pork loins were randomly assigned to one of four treatments to evaluate the use of alkaline electrolyzed reduced water as a replacement for traditional enhancement solutions. Treatments included: alkaline electrolyzed reduced water (EOH; pH≈11.5), EOH plus 2.5% potassium-lactate (EOK), industry standard (IS; 0.35% sodium tri-polyphosphate, 0.14% sodium chloride, 2.5% potassium-lactate), and no enhancement (CON). After enhancement (targeting 110%) and rest period, chops were cut (2.54-cm) to test treatment effects on water holding capacity, Warner-Bratzler shear force (WBSF), and sensory attributes. Despite its alkaline nature EOH chops exuded more water (P<0.05) than EOK, IS, or CON chops. Control chops were similar (P>0.05) to EOK, however CON and EOK both lost more moisture (P<0.05) than IS. The use of alkaline electrolyzed reduced water did not improve WBSF or sensory characteristics compared to IS treated chops. As a stand-alone enhancement solution alkaline electrolyzed reduced water was not a suitable replacement for industry standard solutions.

  11. Fresh water leaching of alkaline bauxite residue after sea water neutralization.

    PubMed

    Menzies, Neal W; Fulton, Ian M; Kopittke, Rosemary A; Kopittke, Peter M

    2009-01-01

    Processing of bauxite to extract alumina produces a strongly alkaline waste, bauxite refining residue, which is commonly stored in engineered structures. Once full, these waste dumps must be revegetated. In many alumina refineries, the waste is separated into fine-textured red mud and coarse-textured residue sand (RS). The sand component has physical characteristics that make it a suitable plant growth medium, provided the adverse chemical characteristics can be addressed. Neutralization of the highly saline-sodic RS with sea water lowers pH, reduces Na saturation, and adds plant nutrients. However, sea water-neutralized RS remains saline sodic and needs fresh water leaching before use as a plant growth medium. Columns containing sea water-neutralized RS were leached with 30 m depth-equivalent of fresh water to evaluate the effects of rainfall on the RS and its leachate. Entrained cations were rapidly displaced by the fresh water, lowering salinity to non-plant-limiting levels (< or =0.3 dS m(-1)). The percentage of the effective cation exchange capacity (ECEC) saturated by Na decreased from 71 to 62% due to a reduction in soil solution ionic strength (causing a decrease in the ECEC) and the preferential displacement of Na(+) (and K(+)) from the exchange. Fresh water leaching increased pH (leachate pH increased from 8.0 to 10.1). This pH increase is attributed to the slow dissolution of the Na-containing mineral sodalite. Under the current experimental conditions, the application of 30 m depth-equivalent of leaching reduced the total RS sodalite content by <10%.

  12. Electrochemical alkaline Fe(VI) water purification and remediation.

    PubMed

    Licht, Stuart; Yu, Xingwen

    2005-10-15

    Fe(VI) is an unusual and strongly oxidizing form of iron, which provides a potentially less hazardous water-purifying agent than chlorine. A novel on-line electrochemical Fe(VI) water purification methodology is introduced. Fe(VI) addition had been a barrier to its effective use in water remediation, because solid Fe(VI) salts require complex (costly) syntheses steps and solutions of Fe(VI) decompose. Online electrochemical Fe(VI) water purification avoids these limitations, in which Fe(VI) is directly prepared in solution from an iron anode as the FeO42- ion, and is added to the contaminant stream. Added FeO42- decomposes, by oxidizing a wide range of water contaminants including sulfides (demonstrated in this study) and other sulfur-containing compounds, cyanides (demonstrated in this study), arsenic (demonstrated in this study), ammonia and other nitrogen-containing compounds (previously demonstrated), a wide range of organics (phenol demonstrated in this study), algae, and viruses (each previously demonstrated).

  13. Long-term evolution of highly alkaline steel slag drainage waters.

    PubMed

    Riley, Alex L; Mayes, William M

    2015-07-01

    The disposal of slag generated by the steel industry can have negative consequences upon the surrounding aquatic environment by the generation of high pH waters, leaching of potentially problematic trace metals, and rapid rates of calcite precipitation which smother benthic habitats. A 36-year dataset was collated from the long-term ambient monitoring of physicochemical parameters and elemental concentrations of samples from two steel slag leachate-affected watercourses in northern England. Waters were typified by elevated pH (>10), high alkalinity, and were rich in dissolved metals (e.g. calcium (Ca), aluminium (Al), and zinc (Zn)). Long-term trend analysis was performed upon pH, alkalinity, and Ca concentration which, in addition to Ca flux calculations, were used to highlight the longevity of pollution arising as a result of the dumping and subsequent leaching of steel slags. Declines in calcium and alkalinity have been modest over the monitoring period and not accompanied by significant declines in water pH. If the monotonic trends of decline in alkalinity and calcium continue in the largest of the receiving streams, it will be in the region of 50-80 years before calcite precipitation would be expected to be close to baseline levels, where ecological impacts would be negligible.

  14. Effects of alkalinity on ammonia removal, carbon dioxide stripping, and system pH in semi-commercial scale water recirculating aquaculture systems operated with moving bed bioreactors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When operating water recirculating systems (RAS) with high make-up water flushing rates in locations that have low alkalinity in the raw water, such as Norway, knowledge about the required RAS alkalinity concentration is important. Flushing RAS with make-up water containing low alkalinity washes out...

  15. Effects of hardness and alkalinity in culture and test waters on reproduction of Ceriodaphnia dubia

    USGS Publications Warehouse

    Lasier, P.J.; Winger, P.V.; Hardin, I.R.

    2006-01-01

    Ceriodaphnia dubia were cultured in four reconstituted water formulations with hardness and alkalinity concentrations ranging from soft to the moderately hard water that is required by whole-effluent toxicity (WET) testing methods for culturing test organisms. The effects of these culture formulations alone and in combination with two levels of Cl-, SO42, and HCO3- on reproduction of C. dubia were evaluated with the standard three-brood test. Reproduction was significantly reduced when test waters had lower hardness than culture waters. However, reproduction was not significantly different when animals cultured in low-hardness waters were exposed to moderately hard waters. The hardness of the culture water did not significantly affect the sensitivity of C. dubia to the three anions. Conversely, increased hardness in test waters significantly reduced the toxicities of Cl- and SO42-, with HCO3- toxicity following the same pattern. Alkalinity exhibited no consistent effect on Cl- and SO42- toxicity. The physiological stress of placing animals cultured in moderately hard water into softer test waters might contribute to marginal failures of otherwise nontoxic effluents. The standard WET protocol should be revised to allow the culture of C. dubia under lower hardness conditions to better represent local surface water chemistries.

  16. Effects of hardness and alkalinity in culture and test waters on reproduction of Ceriodaphnia dubia.

    PubMed

    Lasier, Peter J; Winger, Parley V; Hardin, Ian R

    2006-10-01

    Ceriodaphnia dubia were cultured in four reconstituted water formulations with hardness and alkalinity concentrations ranging from soft to the moderately hard water that is required by whole-effluent toxicity (WET) testing methods for culturing test organisms. The effects of these culture formulations alone and in combination with two levels of Cl-, SO4(2-), and HCO3- on reproduction of C. dubia were evaluated with the standard three-brood test. Reproduction was significantly reduced when test waters had lower hardness than culture waters. However, reproduction was not significantly different when animals cultured in low-hardness waters were exposed to moderately hard waters. The hardness of the culture water did not significantly affect the sensitivity of C. dubia to the three anions. Conversely, increased hardness in test waters significantly reduced the toxicities of Cl- and SO4(2-), with HCO3- toxicity following the same pattern. Alkalinity exhibited no consistent effect on Cl- and SO4(2-) toxicity. The physiological stress of placing animals cultured in moderately hard water into softer test waters might contribute to marginal failures of otherwise nontoxic effluents. The standard WET protocol should be revised to allow the culture of C. dubia under lower hardness conditions to better represent local surface water chemistries.

  17. Determination of soluble aluminium concentration in alkaline humic water using atomic absorption spectrophotometry.

    PubMed

    Nguyen, K L; Lewis, D M; Jolly, M; Robinson, J

    2004-11-01

    The steps of the standard method to determine soluble aluminium concentration are filtering, followed by acidifying, then analysing with the atomic absorption spectrophotometer (AAS). When applied to alkaline humic water, acidification gives rise to the formation of humic acid as a brown particulate matter. Of the total soluble aluminium in the original water, 49-61% forms complexes with the particulate humic acid upon acidification. Although the AAS is capable of detecting the binding aluminium, the particulate nature of humic acid easily induces inaccurate readings as a result of the non-uniform distribution of the particulate matter. A more precise analysis of soluble aluminium concentration of alkaline humic water is shown to be achievable in basicified solutions instead. Basicified solutions keep humic acid in the soluble form; hence maintain the homogeneity of the sample.

  18. Simulation of Stream Water Alkalinity Under Scenarios of Changing Acidic Deposition and Changing Climate.

    NASA Astrophysics Data System (ADS)

    Welsch, D. L.; Cosby, B.; Hornberger, G. M.

    2003-12-01

    Models of soil and stream water and catchment acidification have typically been applied without consideration of climate change. Soil air CO2 concentrations have potential to increase as climate warms and becomes wetter. We simulate this increase by applying a coupled series of models which simulate soil temperature, soil tension, catchment hydrology, soil air CO2 concentrations, and soil and stream water chemistry to predict daily stream water alkalinity values for a small catchment in the Blue Ridge of Virginia for 60 years into the future given stochastically generated daily climate values. This is done for four different scenarios of climate change and atmospheric deposition change. We find that stream water alkalinity continues to decline for all scenarios except when climate is gradually warming and becoming more moist, indicating the influence of increasing soil air CO2 concentrations on stream water chemistry. In all other scenarios, base cation removal from catchment soils is responsible for limited alkalinity change resulting from climate change. This has strong implications given the extent that models such as MAGIC are used to establish policy and legislation concerning deposition and emissions.

  19. Alkaline subcritical water gasification of dairy industry waste (Whey).

    PubMed

    Muangrat, Rattana; Onwudili, Jude A; Williams, Paul T

    2011-05-01

    The near-critical water gasification of dairy industry waste in the form of Whey, a product composed of mixtures of carbohydrates (mainly lactose) and amino acids such as glycine and glutamic acid, has been studied. The gasification process involved partial oxidation with hydrogen peroxide in the presence of NaOH. The reactions were studied over the temperature range from 300°C to 390°C, corresponding pressures of 9.5-24.5 MPa and reaction times from 0 min to 120 min. Hydrogen production was affected by the presence of NaOH, the concentration of H(2)O(2), temperature, reaction time and feed concentration. Up to 40% of the theoretical hydrogen gas production was achieved at 390°C. Over 80% of the Whey nitrogen content was found as ammonia, mainly in the liquid effluent.

  20. Extremely alkaline (pH > 12) ground water hosts diverse microbial community.

    PubMed

    Roadcap, George S; Sanford, Robert A; Jin, Qusheng; Pardinas, José R; Bethke, Craig M

    2006-01-01

    Chemically unusual ground water can provide an environment for novel communities of bacteria to develop. Here, we describe a diverse microbial community that inhabits extremely alkaline (pH > 12) ground water from the Lake Calumet area of Chicago, Illinois, where historic dumping of steel slag has filled in a wetland. Using microbial 16S ribosomal ribonucleic acid gene sequencing and microcosm experiments, we confirmed the presence and growth of a variety of alkaliphilic beta-Proteobacteria, Bacillus, and Clostridium species at pH up to 13.2. Many of the bacterial sequences most closely matched those of other alkaliphiles found in more moderately alkaline water around the world. Oxidation of dihydrogen produced by reaction of water with steel slag is likely a primary energy source to the community. The widespread occurrence of iron-oxidizing bacteria suggests that reduced iron serves as an additional energy source. These results extend upward the known range of pH tolerance for a microbial community by as much as 2 pH units. The community may provide a source of novel microbes and enzymes that can be exploited under alkaline conditions.

  1. Development of conductometric biosensors based on alkaline phosphatases for the water quality control

    NASA Astrophysics Data System (ADS)

    Berezhetskyy, A.

    2008-09-01

    Researches are focused on the elaboration of enzymatic microconductometric device for heavy metal ions detection in water solutions. The manuscript includes a general introduction, the first chapter contains bibliographic review, the second chapter described the fundamentals of conductometric transducers, the third chapter examining the possibility to create and to optimize conductometric biosensor based on bovine alkaline phosphatase for heavy metals ions detection, the fourth chapter devoted to creation and optimization of conductometric biosensor based on alkaline phosphatase active microalgae and sol gel technology, the last chapter described application of the proposed algal biosensor for measurements of heavy metal ions toxicity of waste water, general conclusions stating the progresses achieved in the field of environmental monitoring

  2. Stainless steel anodes for alkaline water electrolysis and methods of making

    SciTech Connect

    Soloveichik, Grigorii Lev

    2014-01-21

    The corrosion resistance of stainless steel anodes for use in alkaline water electrolysis was increased by immersion of the stainless steel anode into a caustic solution prior to electrolysis. Also disclosed herein are electrolyzers employing the so-treated stainless steel anodes. The pre-treatment process provides a stainless steel anode that has a higher corrosion resistance than an untreated stainless steel anode of the same composition.

  3. Electromembrane recycling of highly mineralized alkaline blowdown water from evaporative water treatment plants at thermal power stations

    NASA Astrophysics Data System (ADS)

    Chichirova, N. D.; Chichirov, A. A.; Lyapin, A. I.; Minibaev, A. I.; Silov, I. Yu.; Tolmachev, L. I.

    2016-12-01

    Thermal power stations (TPS) are the main source of highly mineralized effluents affecting the environment. An analysis of their water systems demonstrates that alkaline effluents prevail at TPSs. Extraction of an alkali from highly mineralized effluents can make the recycling of effluents economically feasible. A method is proposed of electromembrane recycling of liquid alkaline highly mineralized wastes from TPSs. The process includes electromembrane apparatuses of two types, namely, a diffusion dialysis extractor (DDE) intended for extraction of the alkali from a highly mineralized solution having a complex composition and an electrodialysis concentrator for increasing the concentration of the extracted solution to a value suitable for use in water treatment plants at TPSs. For implementation of the first process (i.e. the extraction of alkali from alkaline-salt solution) various membranes from various manufacturers were studied: CM-PAD and AM-PAD (Ralex, Czechia), MK-40, MA-40, MA-41, MA-414, and MB-2 (OOO OKhK "Shchekinoazot", Russia), AR103-QDF and CR61-CMP (Ionies Inc., USA). The experiments demonstrate that the acceptable degree of separation of the alkali and the salt is achieved in a pair of cation-exchange membranes with the efficiency of separation being higher without an electric field. The highest efficiency was attained with Russian-made membranes (MK-40, OOO OKhK "Shchekinoazot"). A full scale experiment on recycling of highly-mineralized blowdown water from the evaporating water treatment system at the Kazan cogeneration power station No. 3 (TETs-3) was performed in a pilot unit consisting of two electromembrane apparatuses made by UAB "Membraninės Technologijos LT". In the experiments every ton of blowdown water yielded 0.1 t of concentrated alkaline solution with an alkali content of up to 4 wt % and 0.9 t of the softened salt solution suitable for the reuse in the TPS cycle. The power rate is 6 kWh / ton of blowdown water.

  4. Kinetic Release of Alkalinity from Particle-Containing Oil-in-Water Emulsions

    NASA Astrophysics Data System (ADS)

    Muller, K.; Chapra, S. C.; Ramsburg, A.

    2014-12-01

    Oil-in-water emulsions are typically employed during remediation to promote biotic reduction of contaminants. Emulsions, however, hold promise for encapsulated delivery of many types of active ingredients required for successful site remediation or long-term site stewardship. Our research is currently focused on using alkalinity-containing particles held within oil-in-water emulsions to sustain control of subsurface pH. Here we describe results from laboratory experiments and mathematical modeling conducted to quantify the kinetics associated with the emulsion delivery and alkalinity release process. Kinetically stable oil-in-water emulsions containing (~60 nmCaCO3 or ~100 nm MgO particles) were previously developed using soybean oil and Gum Arabic as a stabilizing agent. Batch and column experiments were employed to assess the accessibility and release of the alkalinity from the emulsion. Successive additions of HCl were used in batch systems to produce several pH responses (pH rebounds) that were subsequently modeled to elucidate release mechanisms and rates for varying emulsion compositions and particle types. Initial results suggest that a linear-driving-force model is generally able to capture the release behavior in the batch system when the temporally-constant, lumped mass-transfer coefficient is scaled by the fraction of particle mass remaining within the droplets. This result suggests that the rate limiting step in the release process may be the interphase transfer of reactive species at the oil-water interface. 1-d column experiments were also completed in order to quantify the extent and rate of alkalinity release from emulsion droplets retained in a sandy medium. Alkalinity release from the retained droplets treated a pH 4 influent water for 25-60 pore volumes (the duration depended on particle type and mass loading), and the cessation in treatment corresponded to exhaustion of the particle mass held within the oil. Column experiments were simulated

  5. Alkaline pretreatment and the synergic effect of water and tetralin enhances the liquefaction efficiency of bagasse.

    PubMed

    Li, Zhixia; Cao, Jiangfei; Huang, Kai; Hong, Yaming; Li, Cunlong; Zhou, Xinxin; Xie, Ning; Lai, Fang; Shen, Fang; Chen, Congjin

    2015-02-01

    Bagasse liquefaction (BL) in water, tetralin, and water/tetralin mixed solvents (WTMS) was investigated, and effects of tetralin content in WTMS, temperature, and alkaline pretreatment of bagasse on liquefaction efficiency were studied. At 300°C, bagasse conversion in WTMS with tetralin content higher than 50 wt% was 86-87 wt%, whereas bagasse conversion in water or tetralin was 67 wt% or 84 wt%, respectively. Because the solid conversion from liquefaction in WTMS with tetralin content higher than 50 wt% was always higher than that in water or tetralin at temperatures between 250 and 300°C, a synergic effect between water and tetralin is suggested. Alkaline pretreatment of bagasse resulted in significantly higher conversion and heavy oil yield from BL in water or WTMS. The effect of deoxygenation by the present liquefaction method is demonstrated by lower oxygen contents (16.01-19.59 wt%) and higher heating values (31.9-34.8 MJ/kg) in the produced oils.

  6. Alkaline water electrolysis technology for Space Station regenerative fuel cell energy storage

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Hoberecht, M. A.; Le, M.

    1986-01-01

    The regenerative fuel cell system (RFCS), designed for application to the Space Station energy storage system, is based on state-of-the-art alkaline electrolyte technology and incorporates a dedicated fuel cell system (FCS) and water electrolysis subsystem (WES). In the present study, emphasis is placed on the WES portion of the RFCS. To ensure RFCS availability for the Space Station, the RFCS Space Station Prototype design was undertaken which included a 46-cell 0.93 cu m static feed water electrolysis module and three integrated mechanical components.

  7. Sequential Washing with Electrolyzed Alkaline and Acidic Water Effectively Removes Pathogens from Metal Surfaces

    PubMed Central

    Nakano, Yuichiro; Akamatsu, Norihiko; Mori, Tsuyoshi; Sano, Kazunori; Satoh, Katsuya; Nagayasu, Takeshi; Miyoshi, Yoshiaki; Sugio, Tomomi; Sakai, Hideyuki; Sakae, Eiji; Ichimiya, Kazuko; Hamada, Masahisa; Nakayama, Takehisa; Fujita, Yuhzo; Yanagihara, Katsunori; Nishida, Noriyuki

    2016-01-01

    Removal of pathogenic organisms from reprocessed surgical instruments is essential to prevent iatrogenic infections. Some bacteria can make persistent biofilms on medical devices. Contamination of non-disposable equipment with prions also represents a serious risk to surgical patients. Efficient disinfection of prions from endoscopes and other instruments such as high-resolution cameras remains problematic because these instruments do not tolerate aggressive chemical or heat treatments. Herein, we develop a new washing system that uses both the alkaline and acidic water produced by electrolysis. Electrolyzed acidic water, containing HCl and HOCl as active substances, has been reported to be an effective disinfectant. A 0.15% NaCl solution was electrolyzed and used immediately to wash bio-contaminated stainless steel model systems with alkaline water (pH 11.9) with sonication, and then with acidic water (pH 2.7) without sonication. Two bacterial species (Staphylococcus aureus and Pseudomonas aeruginosa) and a fungus (Candida albicans) were effectively removed or inactivated by the washing process. In addition, this process effectively removed or inactivated prions from the stainless steel surfaces. This washing system will be potentially useful for the disinfection of clinical devices such as neuroendoscopes because electrolyzed water is gentle to both patients and equipment and is environmentally sound. PMID:27223116

  8. Model-based analysis of water management in alkaline direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Weinzierl, C.; Krewer, U.

    2014-12-01

    Mathematical modelling is used to analyse water management in Alkaline Direct Methanol Fuel Cells (ADMFCs) with an anion exchange membrane as electrolyte. Cathodic water supply is identified as one of the main challenges and investigated at different operation conditions. Two extreme case scenarios are modelled to study the feasible conditions for sufficient water supply. Scenario 1 reveals that water supply by cathodic inlet is insufficient and, thus, water transport through membrane is essential for ADMFC operation. The second scenario is used to analyse requirements on water transport through the membrane for different operation conditions. These requirements are influenced by current density, evaporation rate, methanol cross-over and electro-osmotic drag of water. Simulations indicate that water supply is mainly challenging for high current densities and demands on high water diffusion are intensified by water drag. Thus, current density might be limited by water transport through membrane. The presented results help to identify important effects and processes in ADMFCs with a polymer electrolyte membrane and to understand these processes. Furthermore, the requirements identified by modelling show the importance of considering water transport through membrane besides conductivity and methanol cross-over especially for designing new membrane materials.

  9. Sphagnum establishment in alkaline fens: Importance of weather and water chemistry.

    PubMed

    Vicherová, Eliška; Hájek, Michal; Šmilauer, Petr; Hájek, Tomáš

    2017-02-15

    Sphagnum expansion to alkaline fens has accelerated during the last decades in Europe, leading to changes in diversity, habitat distributions and carbon storage. The causes are still not clearly understood and involve an interplay between climate change, hydrology, nutrient supply and Sphagnum physiology. We conducted a 4-year field experiment in eight fens in Central European highlands and assessed survival and establishment of individual apical shoot fragments of S. flexuosum, S. warnstorfii and S. squarrosum transplanted along the microtopographical gradient. In a laboratory experiment, we tested combined effects of desiccation and high calcium bicarbonate concentration on Sphagnum survival. We found that in unflooded positions, living shoots of Sphagnum and brown mosses lowered [Ca(2+)] and pH in their capillary water, in contrast to dead fragments; yet without differences between species. Survival and expansion of Sphagnum fragments, which did not die of acute calcium toxicity during first weeks/months, was negatively affected by dry weather and alkaline water chemistry, reflecting Sphagnum intolerance to desiccation and to combined high [Ca(2+)] and pH. Shoot fragments expanded to patches only when precipitation was high. Interestingly, non-toxic concentration of calcium bicarbonate reduced desiccation damage in Sphagnum, probably through protection of membranes or other cell components. This mechanism would facilitate Sphagnum survival in elevated, frequently desiccated microhabitats of calcareous fens such as brown-moss hummocks. However, since water-retaining capacity of few Sphagnum shoots is insufficient to change water chemistry in its surroundings, surface acidification may occur only once the environment (e.g. sufficient humidity) enabled expansion to larger mats. Then, the retained rainwater together with hardly decomposable Sphagnum litter would separate mire surface from groundwater, speeding up successional shift towards poor fens. Sphagnum

  10. Separating hydrogen and oxygen evolution in alkaline water electrolysis using nickel hydroxide

    NASA Astrophysics Data System (ADS)

    Chen, Long; Dong, Xiaoli; Wang, Yonggang; Xia, Yongyao

    2016-05-01

    Low-cost alkaline water electrolysis has been considered a sustainable approach to producing hydrogen using renewable energy inputs, but preventing hydrogen/oxygen mixing and efficiently using the instable renewable energy are challenging. Here, using nickel hydroxide as a redox mediator, we decouple the hydrogen and oxygen production in alkaline water electrolysis, which overcomes the gas-mixing issue and may increase the use of renewable energy. In this architecture, the hydrogen production occurs at the cathode by water reduction, and the anodic Ni(OH)2 is simultaneously oxidized into NiOOH. The subsequent oxygen production involves a cathodic NiOOH reduction (NiOOH-->Ni(OH)2) and an anodic OH- oxidization. Alternatively, the NiOOH formed during hydrogen production can be coupled with a zinc anode to form a NiOOH-Zn battery, and its discharge product (that is, Ni(OH)2) can be used to produce hydrogen again. This architecture brings a potential solution to facilitate renewables-to-hydrogen conversion.

  11. Separating hydrogen and oxygen evolution in alkaline water electrolysis using nickel hydroxide

    PubMed Central

    Chen, Long; Dong, Xiaoli; Wang, Yonggang; Xia, Yongyao

    2016-01-01

    Low-cost alkaline water electrolysis has been considered a sustainable approach to producing hydrogen using renewable energy inputs, but preventing hydrogen/oxygen mixing and efficiently using the instable renewable energy are challenging. Here, using nickel hydroxide as a redox mediator, we decouple the hydrogen and oxygen production in alkaline water electrolysis, which overcomes the gas-mixing issue and may increase the use of renewable energy. In this architecture, the hydrogen production occurs at the cathode by water reduction, and the anodic Ni(OH)2 is simultaneously oxidized into NiOOH. The subsequent oxygen production involves a cathodic NiOOH reduction (NiOOH→Ni(OH)2) and an anodic OH− oxidization. Alternatively, the NiOOH formed during hydrogen production can be coupled with a zinc anode to form a NiOOH-Zn battery, and its discharge product (that is, Ni(OH)2) can be used to produce hydrogen again. This architecture brings a potential solution to facilitate renewables-to-hydrogen conversion. PMID:27199009

  12. Separating hydrogen and oxygen evolution in alkaline water electrolysis using nickel hydroxide.

    PubMed

    Chen, Long; Dong, Xiaoli; Wang, Yonggang; Xia, Yongyao

    2016-05-20

    Low-cost alkaline water electrolysis has been considered a sustainable approach to producing hydrogen using renewable energy inputs, but preventing hydrogen/oxygen mixing and efficiently using the instable renewable energy are challenging. Here, using nickel hydroxide as a redox mediator, we decouple the hydrogen and oxygen production in alkaline water electrolysis, which overcomes the gas-mixing issue and may increase the use of renewable energy. In this architecture, the hydrogen production occurs at the cathode by water reduction, and the anodic Ni(OH)2 is simultaneously oxidized into NiOOH. The subsequent oxygen production involves a cathodic NiOOH reduction (NiOOH→Ni(OH)2) and an anodic OH(-) oxidization. Alternatively, the NiOOH formed during hydrogen production can be coupled with a zinc anode to form a NiOOH-Zn battery, and its discharge product (that is, Ni(OH)2) can be used to produce hydrogen again. This architecture brings a potential solution to facilitate renewables-to-hydrogen conversion.

  13. Plant protein hydrolysates (plant peptones) as substitutes for animal proteins in embryo culture medium.

    PubMed

    George, F; Kerschen, D; Van Nuffel, A; Rees, J F; Donnay, I

    2009-01-01

    The aim of the present study was to improve the sanitary quality of in vitro-produced bovine embryos by using plant protein hydrolysates (plant peptones) as substitutes for animal proteins. Peptones were compared with bovine serum albumin (BSA) as the protein source in synthetic oviduct fluid medium and the quality of the resulting embryos was determined. Two batches of peptones (wheat and cotton) were selected on the basis of their anti-oxidant properties. When added to the culture medium, both peptones (at 0.56 mg mL(-1) for cotton peptone and at 0.18 mg mL(-1) for wheat peptone) led to similar developmental and hatching rates compared with 4 mg mL(-1) BSA and embryos were equally resistant to freezing and able to elongate after transfer. Surprisingly, a significant decrease in reduced glutathione (GSH) content was observed when embryos were produced with plant peptone instead of BSA. Supplementation of the culture medium with precursors of GSH (cysteine and beta-mercaptoethanol) significantly increased the GSH content. A shift of the sex ratio towards male embryos was seen for Day 8 embryos cultured with wheat peptone, whereas no shift was observed for embryos cultured in the presence of BSA or polyvinylpyrrolidone. In conclusion, culture with plant peptones enables embryos to be obtained at a similar rate and of similar quality to that seen following the use of BSA. The use of the plant peptones increased the sanitary quality of the embryos and decreased the cost of embryo production.

  14. Activity of alkaline phosphatase in water-in-oil microemulsions containing vegetable oil.

    PubMed

    Gupta, S; Mukhopadhyay, L; Moulik, S P

    1995-10-01

    The hydrolysis of p-nitrophenyl phosphate by the enzyme alkaline phosphatase has been studied in vegetable oil containing water-in-oil (W/O) microemulsions of six different compositions at four different (water)/(surfactant) mole ratios of 10, 17.6, 24.7 and 37. The vegetable oils used are ricebran oil (RO) and clove oil (CO) and the amphiphiles used are Aerosol OT (AOT), cinnamic alcohol (CA) and Tween-20 (T-20). The hydrolytic process does not follow conventional Michaelis Menten equation normally observed for enzymatic process. In the water/vegetable oil microemulsions, the enzyme seems to lose its activity when AOT is the amphiphile. The amount of p-nitrophenol generated as a result of hydrolysis is independent of the presence of the enzyme. With Tween-20 as the amphiphile, the microemulsion produces an initial retarding effect which ultimately gets appreciably compensated.

  15. Alkali doped poly (2,5-benzimidazole) membrane for alkaline water electrolysis: Characterization and performance

    NASA Astrophysics Data System (ADS)

    Diaz, Liliana A.; Hnát, Jaromír; Heredia, Nayra; Bruno, Mariano M.; Viva, Federico A.; Paidar, Martin; Corti, Horacio R.; Bouzek, Karel; Abuin, Graciela C.

    2016-04-01

    The properties and performance of linear and cross-linked KOH doped ABPBI membranes as electrolyte/separator for zero gap alkaline water electrolysis cells are evaluated and compared with a commercial Zirfon® diaphragm. Stability in alkaline environment, swelling, thermal properties, water sorption, KOH uptake and conductivity of linear (L-ABPBI) and cross-linked (C-ABPBI) membranes doped with different concentrations of KOH are analyzed. Linear membranes show stability up to 3.0 mol·dm-3 KOH doping, while cross-linked membranes are stable up to 4.2 mol·dm-3 KOH doping. Both kinds of membranes exhibit good thermal stability and reasonable specific ionic conductivity at 22 °C in the range between 7 and 25 mS·cm-1, being slightly higher the conductivity of C-ABPBI membranes than that of L-ABPBI ones. In short-term electrolysis tests both L-ABPBI and C-ABPBI membranes show better performance than Zirfon diaphragm in the range from 50 to 70 °C. A current density of 335 mA·cm-2 at a cell voltage of 2.0 V is attained with C-ABPBI membranes doped in 3 mol·dm-3 KOH at 70 °C, a performance comparable with that of commercial units operating at temperatures ca. 80 °C and 30 wt% KOH (6.7 mol·dm-3) as electrolyte.

  16. The impact of sedimentary alkalinity release on the water column CO2 system in the North Sea

    NASA Astrophysics Data System (ADS)

    Brenner, H.; Braeckman, U.; Le Guitton, M.; Meysman, F. J. R.

    2016-02-01

    It has been previously proposed that alkalinity release from sediments can play an important role in the carbonate dynamics on continental shelves, lowering the pCO2 of seawater and hence increasing the CO2 uptake from the atmosphere. To test this hypothesis, sedimentary alkalinity generation was quantified within cohesive and permeable sediments across the North Sea during two cruises in September 2011 (basin-wide) and June 2012 (Dutch coastal zone). Benthic fluxes of oxygen (O2), alkalinity (AT) and dissolved inorganic carbon (DIC) were determined using shipboard closed sediment incubations. Our results show that sediments can form an important source of alkalinity for the overlying water, particularly in the shallow southern North Sea, where high AT and DIC fluxes were recorded in near-shore sediments of the Belgian, Dutch and German coastal zone. In contrast, fluxes of AT and DIC are substantially lower in the deeper, seasonally stratified, northern part of the North Sea. Based on the data collected, we performed a model analysis to constrain the main pathways of alkalinity generation in the sediment, and to quantify how sedimentary alkalinity drives atmospheric CO2 uptake in the southern North Sea. Overall, our results show that sedimentary alkalinity generation should be regarded as a key component in the CO2 dynamics of shallow coastal systems.

  17. Hydration process of alkaline-earth metal atoms in water clusters

    NASA Astrophysics Data System (ADS)

    Okai, Nobuhiro; Ishikawa, Haruki; Fuke, Kiyokazu

    2005-10-01

    Ionization potentials (IPs) of water clusters containing alkaline-earth metal atoms are measured by a photoionization threshold method to examine the hydration process of the metal atoms in clusters. IPs of Mg(H 2O) n and Ca(H 2O) n are found to decrease with increasing n and become constant at 3.18 eV for n ⩾ 9 and n ⩾ 8, respectively. The observed constant IP agrees with an estimated photoelectric threshold (3.2 eV) of bulk ice. From the comparison with the results on the theoretical calculations as well as the IPs for alkali atom-water clusters, the anomalous size dependence of IPs is ascribed to the formation of an ion-pair state.

  18. Histopathological influence of alkaline ionized water on myocardial muscle of mother rats.

    PubMed

    Watanabe, T; Shirai, W; Pan, I; Fukuda, Y; Murasugi, E; Sato, T; Kamata, H; Uwatoko, K

    1998-12-01

    We have reported that a marked necrosis and subsequent fibrosis of myocardium occurred among male rats 15 weeks old given alkaline ionized water (AKW) during gestation and suckling periods, and after weaning. In this study, it was examined whether similar lesions would occur in mother rats which were given AKW from day zero of gestation to day 20 of lactation. The myocardial lesion in the mother rats given AKW showed cell infiltration, vacuolation and fibrosis in the papillary muscle of the left ventricle, as were observed in male rats of 15 weeks old. Myocardial degeneration may cause a leakage of potassium into the blood that results in a higher concentration of potassium in the blood in the test group than in that of the control group given tap water.

  19. Variations in the Alkalinity of Seawater in Coastal Waters of Oahu, Hawaii

    NASA Astrophysics Data System (ADS)

    Chen, S. L.; De Carlo, E. H.; Drupp, P. S.; Terlouw, G.; Guidry, M.; Mackenzie, F. T.; Thompson, R.

    2014-12-01

    Total alkalinity (AT) is an important component of the marine inorganic carbon system that, together with one of the other measurable parameters (i.e., pH, dissolved inorganic carbon-CT , pCO2) allows us to calculate the entire CO2-carbonic acid system. By measuring AT continuously at several coastal locations on coral reefs of Oahu, we can calculate a current rate of change in surface water conditions with respect to biogeochemical processes as well as the globally important issue of ocean acidification (OA). Previous work by Drupp et al (2011, 2013) has shown that parameters of the CO2-carbonic acid system display seasonal fluctuations as well as respond to short term rainfall events. This work expands the period of study through July 2014. The three sampling locations are vastly different in geographic and geochemical conditions. Kaneohe Bay is a protected embayment, with large freshwater inputs and long water residence time compared to the nearshore exposed waters at Kilo Nalu and Ala Wai. Variation in coral reef environments affect AT, thus making it crucial to sample multiple environments over an extended period of time to reveal changes in biogeochemistry. A typical sample from Kaneohe Bay (CRIMP-2) can be expected to have a AT value between 2134 umol/kg and 2279 umol/kg, Kilo Nalu: between 2263 umol/kg and 2350 umol/kg, Ala Wai: between 2263 umol/kg and 2335 umol/kg. In general, total alkalinity values from CRIMP-2 are lower than at Kilo Nalu or Ala Wai due to differences in coral reef environments. Our long-term record allows us to compare the behavior of Hawaiian reef waters to those of other tropical marine ecosystems. Furthermore, monitoring of AT over extended multiple years and multiple locations is essential to develop the time-series data necessary for continued evaluation of the impact of OA on coral reefs of the Hawaiian Islands.

  20. Mathematical model of water transport in Bacon and alkaline matrix-type hydrogen-oxygen fuel cells

    NASA Technical Reports Server (NTRS)

    Prokopius, P. R.; Easter, R. W.

    1972-01-01

    Based on general mass continuity and diffusive transport equations, a mathematical model was developed that simulates the transport of water in Bacon and alkaline-matrix fuel cells. The derived model was validated by using it to analytically reproduce various Bacon and matrix-cell experimental water transport transients.

  1. Biological Apatite Formed from Polyphosphate and Alkaline Phosphatase May Exchange Oxygen Isotopes from Water through Carbonate

    NASA Astrophysics Data System (ADS)

    Omelon, S. J.; Stanley, S. Y.; Gorelikov, I.; Matsuura, N.

    2011-12-01

    The oxygen isotopic composition in bone mineral phosphate is known to reflect the local water composition, environmental humidity, and diet1. Once ingested, biochemical processes presumably equilibrate PO43- with "body water" by the many biochemical reactions involving PO43- 2. Blake et al. demonstrated that enzymatic release of PO43- from organophosphorus compounds, and microbial metabolism of dissolved orthophosphate, significantly exchange the oxygen in precipitated apatite within environmental water3,4, which otherwise does not exchange with water at low temperatures. One of the enzymes that can cleave phosphates from organic substrates is alkaline phosphastase5, the enzyme also associated with bone mineralization. The literature often states that the mineral in bone in hydroxylapatite, however the mineral in bone is carbonated apatite that also contains some fluoride6. Deprotonation of HPO32- occurs at pH 12, which is impossibly high for biological system, and the predominate carbonate species in solution at neutral pH is HCO3-. To produce an apatite mineral without a significant hydroxyl content, it is possible that apatite biomineralization occurs through a polyphosphate pathway, where the oxygen atom required to transform polyphosphate into individual phosphate ions is from carbonate: [PO3-]n + CO32- -> [PO3-]n-1 + PO43- + CO2. Alkaline phosphatase can depolymerise polyphosphate into orthophosphate5. If alkaline phosphatase cleaves an oxygen atom from a calcium-carbonate complex, then there is no requirement for removing a hydrogen atom from the HCO3- or HPO43- ions of body water to form bioapatite. A mix of 1 mL of 1 M calcium polyphosphate hydogel, or nano-particles of calcium polyphosphate, and amorphous calcium carbonate were reacted with alkaline phosphatase, and maintained at neutral to basic pH. After two weeks, carbonated apatite and other calcium phosphate minerals were identified by powder x-ray diffraction. Orthophosphate and unreacted

  2. Theoretical considerations and a simple method for measuring alkalinity and acidity in low-pH waters by gran titration

    USGS Publications Warehouse

    Barringer, J.L.; Johnsson, P.A.

    1996-01-01

    Titrations for alkalinity and acidity using the technique described by Gran (1952, Determination of the equivalence point in potentiometric titrations, Part II: The Analyst, v. 77, p. 661-671) have been employed in the analysis of low-pH natural waters. This report includes a synopsis of the theory and calculations associated with Gran's technique and presents a simple and inexpensive method for performing alkalinity and acidity determinations. However, potential sources of error introduced by the chemical character of some waters may limit the utility of Gran's technique. Therefore, the cost- and time-efficient method for performing alkalinity and acidity determinations described in this report is useful for exploring the suitability of Gran's technique in studies of water chemistry.

  3. Enhanced bioaccumulation of mercury, cadmium and lead in low-alkalinity waters: An emerging regional environmental problem

    USGS Publications Warehouse

    Wiener, J.G.; Stokes, P.M.

    1990-01-01

    During the past decade or so, observations of high mercury concentrations in fish have renewed concerns and mercury, primarily in two groups of fresh waters: low-alkalinity lakes (the topic of this editorial) and newly created impoundments. The recent focus on the chemistry and biota of low-alkalinity (< 50 mu eq/L) waters stemmed largely from concerns about acidic deposition and its effects on sensitive aquatic ecosystems. Such studies have revealed high concentrations of mercury in biota from low-alkalinity waters in some regions--even in seemingly pristine, semi-remote watersheds lacking both identifiable anthropogenic sources of the metal and mercury-enriched ores. Consequently, much of the concern about mercury in aquatic systems has shifted from direct point sources to more diffuse, poorly defined sources, possibly associated with atmospheric transport and deposition.

  4. Influence of Hydration Level on Polymer and Water Dynamics in Alkaline Anion Exchange Fuel Cell Membranes

    NASA Astrophysics Data System (ADS)

    Tarver, Jacob; Kim, Jenny; Tyagi, Madhu; Soles, Christopher; Tsai, Tsung-Han; Coughlin, Bryan

    2015-03-01

    Triblock copolymers based on poly(chloromethylstyrene)-b-poly(ethylene)-b-poly(chloromethylstyrene) can be quaternized to different extents to yield anion exchange membranes for alkaline fuel cells. In the absence of moisture, these membranes demonstrate bilayer lamellar morphology. Upon high levels of hydration, however, in-situ small angle neutron scattering reveals the emergence of higher-order diffraction peaks. This phenomena has previously been observed in analogous diblock copolymer-based membranes and has been attributed to the induction of a multilayer lamellar morphology in which selective striping of water occurs in the center of the ion-rich domain. By conducting humidity-resolved quasielastic neutron scattering (QENS) measurements using deuterated water, we are able to isolate differences in the pico- to nanosecond timescale dynamics of the hydrogenated membrane upon hydration. QENS measurements in the presence of a hydrogenated water source subsequently permit deconvolution and isolation of the translational and rotational dynamics of water as a function of relative humidity, revealing spatial and temporal changes in polymer and water motion at high levels of hydration.

  5. Development and operation of a hybrid acid-alkaline advanced water electrolysis cell

    NASA Astrophysics Data System (ADS)

    Teschke, O.; Zwanziger, M.

    A hybrid acid-alkaline water electrolysis cell has been developed for hydrogen production. The cell is based on the use of an acidic solution at the cathode and a basic solution at the anode to reduce the minimum theoretical voltage for water decomposition from the thermoneutral potential of 1.47 V to close to 1.4 V at 25 C and 1 atm. The pH differential is maintained by the removal of OH ions from the cathode section and water removal from the anode section, which can be driven by heat energy. A practical cell has been built using a solid polymer electrolyte in which, however, the cathodic compartment is not acidic but neutral. Tests with a platinum black cathode catalyst and a platinum-iridium anode catalyst have resulted in steady-state water hydrolysis at an applied voltage of 0.9 V, and a V-I diagram with a considerably lower slope than that of a conventional cell has been obtained at 90 C.

  6. Comparison of liquid hot water and alkaline pretreatments of giant reed for improved enzymatic digestibility and biogas energy production.

    PubMed

    Jiang, Danping; Ge, Xumeng; Zhang, Quanguo; Li, Yebo

    2016-09-01

    Liquid hot water (LHW) and alkaline pretreatments of giant reed biomass were compared in terms of digestibility, methane production, and cost-benefit efficiency for electricity generation via anaerobic digestion with a combined heat and power system. Compared to LHW pretreatment, alkaline pretreatment retained more of the dry matter in giant reed biomass solids due to less severe conditions. Under their optimal conditions, LHW pretreatment (190°C, 15min) and alkaline pretreatment (20g/L of NaOH, 24h) improved glucose yield from giant reed by more than 2-fold, while only the alkaline pretreatment significantly (p<0.05) increased cumulative methane yield (by 63%) over that of untreated biomass (217L/kgVS). LHW pretreatment obtained negative net electrical energy production due to high energy input. Alkaline pretreatment achieved 27% higher net electrical energy production than that of non-pretreatment (3859kJ/kg initial total solids), but alkaline liquor reuse is needed for improved net benefit.

  7. Vesiculation processes in a water-rich calc-alkaline obsidian

    NASA Astrophysics Data System (ADS)

    Stevenson, R. J.; Bagdassarov, N. S.; Romano, C.

    1997-02-01

    The effect of temperature and viscosity on the kinetics of bubble growth was measured for a natural water-rich rhyolite melt. The change in volume of a natural crystal-poor calc-alkaline rhyolitic obsidian with an initial water content of ≈ 1.8 wt% H 2O was determined in the temperature interval 520-624°C. Shear viscosity was measured on the natural sample using the micropenetration method in the temperature interval 450-590°C and water contents before and after viscometry were monitored by FTIR. The time-dependence of the volume increase as a result of vesiculation approximates the Avrami equation: ΔV(t) α 1- exp[-( t/τ) n] . At temperatures close to the glass transition temperature (T g), growing bubbles ruptured the surrounding melt. During diffusion of water from the hydrous melt with ≈ 1.8 wt% H 2O into a bubble, the ΔT g of the melt at the bubble wall increases by ≈ 315°C. In addition, the viscosity of the melt at the bubble wall increases by 5-6 orders of magnitude. The increasing elastic component of shear stress on the bubble wall as a result of bubble growth at ˜ T g may exceed the bubble wall yield strength, resulting in cracking. No time lag in the onset of bubble growth occurred for this water-rich rhyolite. In those parts of volcanic edifices where water contents are of several weight percent (e.g., within the upper parts of volcanic conduits), the probability of melt fracturing due to the degassing of water at ˜ T g increases.

  8. The effect of peptone on the structure of electrodeposited Sn-Fe binary alloys

    NASA Astrophysics Data System (ADS)

    Lak, G. B.; Sziráki, L.; Kuzmann, E.; Stichleutner, S.; Chisholm, C. U.; El-Sharif, M.; Varga, G.; Havancsák, K.; Homonnay, Z.

    2016-12-01

    Sn-Fe thin films were electrodeposited by constant current deposition on copper substrates using an aqueous gluconate based electrolyte with varying concentrations of the organic additive peptone. Good quality metallic deposits were obtained with surface morphologies which varied with the concentration of peptone present in the electrolyte. The effect of peptone concentration on the deposition process was studied using electrochemical polarization curves and EDX analysis. The effect of peptone concentration on deposit structure and surface morphology was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and 57Fe and 119Sn conversion electron Mössbauer spectroscopy (CEMS). It was concluded that the addition of small amounts of peptone to the electrolyte slightly increased the bath stability and led to changes in the alloy composition of the electrodeposits. It was found that increases in the peptone content increased the amount of the crystalline structure in the deposits with corresponding reductions in the amounts of amorphous structure present in the deposits.

  9. Improvement in the solid-state alkaline fuel cell performance through efficient water management strategies

    NASA Astrophysics Data System (ADS)

    Oshiba, Yuhei; Hiura, Junya; Suzuki, Yuto; Yamaguchi, Takeo

    2017-03-01

    In solid-state alkaline fuel cells (SAFCs), water is generated at the anode and is reacted at the cathode; as such, flooding occurs much more easily at the anode than it does in proton-exchange membrane fuel cells (PEMFCs). Anode flooding is a reason for the low performance of SAFCs, and so it is important that this flooding phenomenon is mitigated. In this study, we control water transport to suppress anode flooding. We do this through two approaches: changing the thickness of the anion exchange membrane (AEM) and changing the anode flow rate. Among two AEMs with two different thicknesses (27 μm and 6 μm) prepared, thinner AEM shows improved fuel cell performance. Increasing the anode flow rate also improved the performance of SAFCs. To find out what caused this, the water transport inside the membrane electrode assembly (MEA) was analyzed. The flooding region was estimated using calculated relative humidity at anode outlet. On the basis of our experimental and calculation approaches, flooding can be suppressed by using thin AEMs and increasing the anode flow rate.

  10. Hydrology and Alkalinity Regulation of Soft Florida Waters: An Integrated Assessment

    NASA Astrophysics Data System (ADS)

    Stauffer, Robert E.; Canfield, Daniel E., Jr.

    1992-06-01

    Natural waters in ridge provinces of Florida and southeast Georgia were classified geographically, by degrees of cultural disturbance, and according to the dominant hydrologic and biogeochemical processes controlling chemistry. The ionic composition of lakes, upland streams, and surficial aquifer (water table) springs in relatively undeveloped catchments reflects the geographic variations in bulk deposition corrected for evapotranspiration (Na, Cl), plus a slight gain (net watershed mobilization) of Mg, and partial to nearly complete losses (net retention) of nitrate, sulfate, Ca, and K. Recharge to the Floridan aquifer in infertile, forested, sandy ridge provinces of northern Florida contains 360-580 μmol CO2. On the basis of indirect geochemical evidence, sulfate retention appears less important in lake sediments than in the region's highly weathered, ferruginous, kaolinitic, sand soils. Silica concentrations in upland streams and water table springs closely reflect the predicted equilibrium between kaolinite and gibbsite. Along with other evidence, the Si concentrations in ridge lakes indicate that seepage inflow is much more important than assumed in Baker et al.'s (1988) regional model. Lakes and streams are acidified either by humic acids or nonmarine sulfate but rarely by both, as reflected by the significant inverse correlation between these two components. Contrary to previous reports, there is no significant difference in alkalinity for culturally undisturbed lakes in the northern Trail versus southern Highlands Ridge areas.

  11. Managing land application of coal seam water: A field study of land amendment irrigation using saline-sodic and alkaline water on a Red Vertisol.

    PubMed

    Bennett, J McL; Marchuk, A; Raine, S R; Dalzell, S A; Macfarlane, D C

    2016-12-15

    Coal seam (CS) gas operations coproduce water with gas from confined CS aquifers. This CS water represents a potential agricultural resource if the water is able to be chemically amended to comply with management guidelines. Stoichiometric quantities of sulphur and gypsum amendments can be used to neutralise the alkalinity and reduce the sodicity of CS water respectively. These amendments can either be mixed in-line at a water treatment plant or applied directly to land prior to the application of CS water (a practice termed land amendment irrigation - LAI). This study compared the efficacy of LAI with in-line chemical amendment of CS water and irrigation with non-saline, non-sodic and non-alkaline (good quality) water under field conditions in southern Queensland. Soil chemical properties, soluble Ca, Mg, K, Na, electrical conductivity (EC), pH, chloride and alkalinity, as well as saturated hydraulic conductivity were measured to determine the impact of the irrigation treatments on soil chemical and physical conditions. Irrigation of lucerne pasture using solid-set sprinklers applied a total of 6.7 ML/ha of each treatment irrigation water to the experimental plots over a 10-month period. Alkalinity was neutralised using LAI, with no increase in soil alkalinity observed. Soil sodicity did not exceed threshold electrolyte concentration values under either CS water irrigation treatment. Soil chemical and physical properties were comparable for both LAI and in-line chemical amendment of CS water. Soil saturated hydraulic conductivity was maintained under all irrigation treatments. Results showed that the constrained capacity of the irrigation system was unable to meet crop evapotranspiration demand. This resulted in accumulation of salt within the root-zone under the CS water treatments compared to the good quality water treatment. LAI successfully chemically amended Bowen Basin CS water facilitating its beneficial use for agricultural irrigation.

  12. Volatile fatty acids production from anaerobic treatment of cassava waste water: effect of temperature and alkalinity.

    PubMed

    Hasan, Salah Din Mahmud; Giongo, Citieli; Fiorese, Mônica Lady; Gomes, Simone Damasceno; Ferrari, Tatiane Caroline; Savoldi, Tarcio Enrico

    2015-01-01

    The production of volatile fatty acids (VFAs), intermediates in the anaerobic degradation process of organic matter from waste water, was evaluated in this work. A batch reactor was used to investigate the effect of temperature, and alkalinity in the production of VFAs, from the fermentation of industrial cassava waste water. Peak production of total volatile fatty acids (TVFAs) was observed in the first two days of acidogenesis. A central composite design was performed, and the highest yield (3400 mg L(-1) of TVFA) was obtained with 30°C and 3 g L(-1) of sodium bicarbonate. The peak of VFA was in 45 h (pH 5.9) with a predominance of acetic (63%) and butyric acid (22%), followed by propionic acid (12%). Decreases in amounts of cyanide (12.9%) and chemical oxygen demand (21.6%) were observed, in addition to the production of biogas (0.53 cm(3) h(-1)). The process was validated experimentally and 3400 g L(-1) of TVFA were obtained with a low relative standard deviation.

  13. Effect of CaCO3(S) nucleation modes on algae removal from alkaline water.

    PubMed

    Choi, Jin Yong; Kinney, Kerry A; Katz, Lynn E

    2016-02-29

    The role of calcite heterogeneous nucleation was studied in a particle coagulation treatment process for removing microalgae from water. Batch experiments were conducted with Scenedesmus sp. and Chlorella sp. in the presence and absence of carbonate and in the presence and absence of Mg to delineate the role of CaCO3(S) nucleation on microalgae removal. The results indicate that effective algae coagulation (e.g., up to 81 % algae removal efficiency) can be achieved via heterogeneous nucleation with CaCO3(S); however, supersaturation ratios between 120 and 200 are required to achieve at least 50% algae removal, depending on ion concentrations. Algae removal was attributed to adsorption of Ca(2+) onto the cell surface which provides nucleation sites for CaCO3(S) precipitation. Bridging of calcite particles between the algal cells led to rapid aggregation and formation of larger flocs. However, at higher supersaturation conditions, algae removal was diminished due to the dominance of homogeneous nucleation of CaCO3(S). Removal of algae in the presence of Ca(2+) and Mg(2+) required higher supersaturation values; however, the shift from heteronucleation to homonucleation with increasing supersaturation was still evident. The results suggest that water chemistry, pH, ionic strength, alkalinity and Ca(2+) concentration can be optimized for algae removal via coagulation-sedimentation.

  14. Anti-obesity effect of alkaline reduced water in high fat-fed obese mice.

    PubMed

    Ignacio, Rosa Mistica Coles; Kang, Tae-Young; Kim, Cheol-Su; Kim, Soo-Ki; Yang, Young-Chul; Sohn, Joon-Hyung; Lee, Kyu-Jae

    2013-01-01

    Whether or not alkaline reduced water (ARW) has a positive effect on obesity is unclear. This study aims to prove the positive effect of ARW in high-fat (HF) diet-induced obesity (DIO) in C57BL/6 mice model. Toward this, obesity was induced by feeding the C57BL/6 male mice with high-fat diet (w/w 45% fat) for 12 weeks. Thereafter, the animals were administered with either ARW or tap water. Next, the degree of adiposity and DIO-associated parameters were assessed: clinico-pathological parameters, biochemical measurements, histopathological analysis of liver, the expression of cholesterol metabolism-related genes in the liver, and serum levels of adipokine and cytokine. We found that ARW-fed mice significantly ameliorated adiposity: controlled body weight gain, reduced the accumulation of epididymal fats and decreased liver fats as compared to control mice. Accordingly, ARW coordinated the level of adiponectin and leptin. Further, mRNA expression of cytochrome P450 (CYP)7A1 was upregulated. In summary, our data shows that ARW intake inhibits the progression of HF-DIO in mice. This is the first note on anti-obesity effect of ARW, clinically implying the safer fluid remedy for obesity control.

  15. Influences of alkaline ionized water on milk electrolyte concentrations in maternal rats.

    PubMed

    Watanabe, T; Kamata, H; Fukuda, Y; Murasugi, E; Sato, T; Uwatoko, K; Pan, I J

    2000-12-01

    We previously reported that body weight on day 14 after birth in male offspring of rats given alkaline ionized water (AKW) was significantly heavier than that in offspring of rats given tap water (TPW), but no significant difference was noted in milk yield and in suckled milk volume between the two groups. Additionally, the offspring in the AKW group and TPW group were given AKW and TPW, respectively, at weaning, and unexpectedly, the necrotic foci in the cardiac muscle were observed at the 15-week-old age in the AKW group, but not in the TPW group. The present study was designed to clarify the factors which are involved in that unusual increase of body weight and occurrence of cardiac necrosis. Eight dams in each group were given AKW or TPW (control) from day 0 of gestation to day 14 of lactation. The milk samples were collected on day 14 of lactation and analyzed for concentrations of calcium (Ca), sodium (Na), potassium (K), magnesium (Mg) and chloride (Cl). The AKW and TPW were also analyzed. Ca, Na and K levels in milk were significantly higher in the AKW group compared to the TPW group. No significant difference was noted in the Mg and Cl levels between the two groups. These data suggested that the Ca cation of AKW enriched the Ca concentration of the milk and accelerated the postnatal growth of the offspring of rats given AKW.

  16. Heavy water reactions with alkaline-earth metal dications in the gas phase

    NASA Astrophysics Data System (ADS)

    Feil, Stefan; Koyanagi, Greg K.; Bohme, Diethard K.

    2009-02-01

    Room temperature rate coefficients and product distributions are reported for the reactions initiated in D2O with dications of the alkaline-earth metals Mg, Ca, Sr and Ba. The measurements were performed with a selected-ion flow tube (SIFT) tandem mass spectrometer and electrospray ionization (ESI). Mg2+ reacts with water by a fast electron transfer leading to charge separation with a rate coefficient of 1.4 × 10-9 cm3 molecule-1 s-1. Ca2+ reacts with D2O in a first step to form the adduct Ca2+(D2O), with an effective bimolecular rate coefficient of 2.3 × 10-11 cm3 molecule-1 s-1, which then undergoes rapid charge separation by deuteron transfer to form CaOD+ and D3O+ in a second step with k = 7.9 × 10-10 cm3 molecule-1 s-1. The CaOD+ ion reacts further by clustering up to five more D2O molecules. Sr2+ clusters up to eight D2O molecules and Ba2+ up to seven D2O molecules, with the first addition of D2O being rate determining in each case and the last addition being distinctly slower, as might be expected from a transition in the occupation of the added water molecules from an inner to an outer hydration shell.

  17. Sulfur-oxidizing autotrophic and mixotrophic denitrification processes for drinking water treatment: elimination of excess sulfate production and alkalinity requirement.

    PubMed

    Sahinkaya, Erkan; Dursun, Nesrin

    2012-09-01

    This study evaluated the elimination of alkalinity need and excess sulfate generation of sulfur-based autotrophic denitrification process by stimulating simultaneous autotrophic and heterotrophic (mixotrophic) denitrification process in a column bioreactor by methanol supplementation. Also, denitrification performances of sulfur-based autotrophic and mixotrophic processes were compared. In autotrophic process, acidity produced by denitrifying sulfur-oxidizing bacteria was neutralized by the external NaHCO(3) supplementation. After stimulating mixotrophic denitrification process, the alkalinity need of the autotrophic process was satisfied by the alkalinity produced by heterotrophic denitrifiers. Decreasing and lastly eliminating the external alkalinity supplementation did not adversely affect the process performance. Complete denitrification of 75 mg L(-1) NO(3)-N under mixotrophic conditions at 4 h hydraulic retention time was achieved without external alkalinity supplementation and with effluent sulfate concentration lower than the drinking water guideline value of 250 mg L(-1). The denitrification rate of mixotrophic process (0.45 g NO(3)-N L(-1) d(-1)) was higher than that of autotrophic one (0.3 g NO(3)-N L(-1) d(-1)). Batch studies showed that the sulfur-based autotrophic nitrate reduction rate increased with increasing initial nitrate concentration and transient accumulation of nitrite was observed.

  18. Removal of K+, Na+, Ca2+, and Mg2+ from saline-alkaline water using the microalga Scenedesmus obliquus

    NASA Astrophysics Data System (ADS)

    Yao, Zongli; Ying, Chengqi; Lu, Jianxue; Lai, Qifang; Zhou, Kai; Wang, Hui; Chen, Ling

    2013-11-01

    The capability of Scenedesmus obliquus to remove cations (K+, Na+, Ca2+, Mg2+) from saline-alkaline water was investigated at different salinities (0, 5, 10, 15, 20, 25) and carbonate alkalinities (0, 5, 10, 15, 20, 25, 30, 35 mmol/L). K+, Na+, Ca2+, and Mg2+ in saline-alkaline water were efficiently removed by S. obliquus. The maximum removal of the cations (29.37 mg for K+, 185.85 mg for Na+, 23.07 mg for Ca2+, 66.14 mg for Mg2+) occurred at salinity 25. The maximum removal of K+ (2.28 mg), Na+ (6.62 mg), Ca2+ (1.01 mg), and Mg2+ (0.62 mg) occurred at carbonate alkalinities of 25 mmol/L for K+, 35 mmol/L for Na+, 20 mmol/L for Ca2+, and 25 mmol/L for Mg2+, respectively. Under a salinity stress, the concentration of Na+ in S. obliquus increased significantly, while that of K+ decreased significantly. The concentrations of Ca2+ and Mg2+ decreased as well. The ratios of K+/Na+, Ca2+/Na+, and Mg2+/Na+ were significantly lower in all salinity treatments than those of the control. Under alkaline stress, the concentrations of Na+ and K+ in S. obliquus decreased significantly and the ratios of K+/Na+, Ca2+/Na+, and Mg2+/Na+ were significantly higher in all treatments than in the control. Moreover, the concentrations of Ca2+ and Mg2+ in S. obliquus at alkalinities of 5-10 mmol/L were significantly higher than those of the other treatments. The removal of Na+ by S. obliquus mainly occurs through biosorption, and Mg2+ and Ca2+ were removed through both biosorption and bioaccumulation.

  19. Climatological variations of total alkalinity and total dissolved inorganic carbon in the Mediterranean Sea surface waters

    NASA Astrophysics Data System (ADS)

    Gemayel, E.; Hassoun, A. E. R.; Benallal, M. A.; Goyet, C.; Rivaro, P.; Abboud-Abi Saab, M.; Krasakopoulou, E.; Touratier, F.; Ziveri, P.

    2015-12-01

    A compilation of data from several cruises between 1998 and 2013 was used to derive polynomial fits that estimate total alkalinity (AT) and total dissolved inorganic carbon (CT) from measurements of salinity and temperature in the Mediterranean Sea surface waters. The optimal equations were chosen based on the 10-fold cross-validation results and revealed that second- and third-order polynomials fit the AT and CT data respectively. The AT surface fit yielded a root mean square error (RMSE) of ± 10.6 μmol kg-1, and salinity and temperature contribute to 96 % of the variability. Furthermore, we present the first annual mean CT parameterization for the Mediterranean Sea surface waters with a RMSE of ± 14.3 μmol kg-1. Excluding the marginal seas of the Adriatic and the Aegean, these equations can be used to estimate AT and CT in case of the lack of measurements. The identified empirical equations were applied on the 0.25° climatologies of temperature and salinity, available from the World Ocean Atlas 2013. The 7-year averages (2005-2012) showed that AT and CT have similar patterns with an increasing eastward gradient. The variability is influenced by the inflow of cold Atlantic waters through the Strait of Gibraltar and by the oligotrophic and thermohaline gradient that characterize the Mediterranean Sea. The summer-winter seasonality was also mapped and showed different patterns for AT and CT. During the winter, the AT and CT concentrations were higher in the western than in the eastern basin. The opposite was observed in the summer where the eastern basin was marked by higher AT and CT concentrations than in winter. The strong evaporation that takes place in this season along with the ultra-oligotrophy of the eastern basin determines the increase of both AT and CT concentrations.

  20. Critical anomalies of alkaline fading of phenolphthalein in the critical solution of 2-butoxyethanol + water

    NASA Astrophysics Data System (ADS)

    Du, Zhongyu; Yin, Handi; Hao, Zhiguo; Zheng, Peizhu; Shen, Weiguo

    2013-12-01

    We have used three-wavelength UV-spectrophotometry to study the reaction of the alkaline fading of phenolphthalein in the critical solution of 2-butoxyethanol + water. It was found that when the temperature was far away from the critical point, the values of the natural logarithm of the rate constant k and the natural logarithm of the chemical equilibrium K determined in our experiments had good linear relationships with the reciprocal of temperature, which served as the backgrounds and were used for correcting k and K in the critical region. The critical slowing down of the reaction and the critical anomaly of the chemical equilibrium were detected near the critical point. The value of the critical exponent characterizing the slowing down effect of the reaction rate was obtained to be 0.156, which was close to the value 0.11 associated with the heat capacity divergence and agreed with the theoretical prediction. The experimental result also confirmed the theoretical prediction of 0.11 for the critical exponent characterizing the weak divergence of the singularity of the chemical equilibrium.

  1. Cobalt phosphide based nanostructures as bifunctional electrocatalysts for low temperature alkaline water splitting

    SciTech Connect

    Lambert, Timothy N.; Vigil, Julian A.; Christensen, Ben

    2016-08-22

    Cobalt phosphide based thin films and nanoparticles were prepared by the thermal phosphidation of spinel Co3O4 precursor films and nanoparticles, respectively. CoP films were prepared with overall retention of the Co3O4 nanoplatelet morphology while the spherical/cubic Co3O4 and Ni0.15Co2.85O4 nanoparticles were converted to nanorods or nanoparticles, respectively. The inclusion of nickel in the nanoparticles resulted in a 2.5 fold higher surface area leading to higher gravimetric performance. In each case high surface area structures were obtained with CoP as the primary phase. All materials were found to act as effective bifunctional electrocatalysts for both the HER and the OER and compared well to commercial precious metal benchmark materials in alkaline electrolyte. As a result, a symmetrical water electrolysis cell prepared from the CoP-based film operated at a low overpotential of 0.41-0.51 V.

  2. Control of alkaline stress corrosion cracking in pressurized-water reactor steam generator tubing

    SciTech Connect

    Hwang, I.S. . Dept. of Nuclear Engineering); Park, I.G. . Div. of Materials Science and Engineering)

    1999-06-01

    Outer-diameter stress corrosion cracking (ODSCC) of alloy 600 (UNS N06600) tubings in steam generators of the Kori-1 pressurized-water reactor (PWR) caused an unscheduled outage in 1994. Failure analysis and remedy development studies were undertaken to avoid a recurrence. Destructive examination of a removed tube indicated axial intergranular cracks developed at the top of sludge caused by a boiling crevice geometry. A high ODSCC propagation rate was attributed to high local pH and increased corrosion potential resulting from oxidized copper presumably formed during the maintenance outage and plant heatup. Remedial measures included: (1) crevice neutralization by crevice flushing with boric acid (H[sub 3]BO[sub 3]) and molar ratio control using ammonium chloride (NH[sub 4]Cl), (2) corrosion potential reduction by hydrazine (H[sub 2]NNH[sub 2]) soaking and suppression of oxygen below 20 ppb to avoid copper oxide formation, (3) titanium dioxide (TiO[sub 2]) inhibitor soaking, and (4) temperature reduction of 5 C. Since application of the remedy program, no significant ODSCC has been observed, which clearly demonstrates the benefit of departing from an oxidizing alkaline environment. In addition, the TiO[sub 2] inhibitor appeared to have a positive effect, warranting further examination.

  3. Cobalt phosphide based nanostructures as bifunctional electrocatalysts for low temperature alkaline water splitting

    DOE PAGES

    Lambert, Timothy N.; Vigil, Julian A.; Christensen, Ben

    2016-08-22

    Cobalt phosphide based thin films and nanoparticles were prepared by the thermal phosphidation of spinel Co3O4 precursor films and nanoparticles, respectively. CoP films were prepared with overall retention of the Co3O4 nanoplatelet morphology while the spherical/cubic Co3O4 and Ni0.15Co2.85O4 nanoparticles were converted to nanorods or nanoparticles, respectively. The inclusion of nickel in the nanoparticles resulted in a 2.5 fold higher surface area leading to higher gravimetric performance. In each case high surface area structures were obtained with CoP as the primary phase. All materials were found to act as effective bifunctional electrocatalysts for both the HER and the OER andmore » compared well to commercial precious metal benchmark materials in alkaline electrolyte. As a result, a symmetrical water electrolysis cell prepared from the CoP-based film operated at a low overpotential of 0.41-0.51 V.« less

  4. Hydrogen-rich water affected blood alkalinity in physically active men.

    PubMed

    Ostojic, Sergej M; Stojanovic, Marko D

    2014-01-01

    Possible appliance of effective and safe alkalizing agent in the treatment of metabolic acidosis could be of particular interest to humans experiencing an increase in plasma acidity, such as exercise-induced acidosis. In the present study we tested the hypothesis that the daily oral intake of 2L of hydrogen-rich water (HRW) for 14 days would increase arterial blood alkalinity at baseline and post-exercise as compared with the placebo. This study was a randomized, double blind, placebo-controlled trial involving 52 presumably healthy physically active male volunteers. Twenty-six participants received HRW and 26 a placebo (tap water) for 14 days. Arterial blood pH, partial pressure for carbon dioxide (pCO2), and bicarbonates were measured at baseline and postexercise at the start (day 0) and at the end of the intervention period (day 14). Intake of HRW significantly increased fasting arterial blood pH by 0.04 (95% confidence interval; 0.01 - 0.08; p < 0.001), and postexercise pH by 0.07 (95% confidence interval; 0.01 - 0.10; p = 0.03) after 14 days of intervention. Fasting bicarbonates were significantly higher in the HRW trial after the administration regimen as compared with the preadministration (30.5 ± 1.9 mEq/L vs. 28.3 ± 2.3 mEq/L; p < 0.0001). No volunteers withdrew before the end of the study, and no participant reported any vexatious side effects of supplementation. These results support the hypothesis that HRW administration is safe and may have an alkalizing effect in young physically active men.

  5. The non-nutritional performance characteristics of peptones made from rendered protein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Economic considerations require the use of inexpensive feedstocks for the fermentative production of moderate value products. Our previous work has shown that peptones capable of supporting the growth of various microorganisms can be produced from inexpensive animal proteins, including meat & bone ...

  6. Signalling pathways involved in the detection of peptones by murine small intestinal enteroendocrine L-cells

    PubMed Central

    Pais, Ramona; Gribble, Fiona M; Reimann, Frank

    2016-01-01

    Glucagon like peptide-1 is an insulinotropic hormone released from intestinal L-cells in response to food ingestion. Here, we investigated mechanisms underlying the sensing of peptones by primary small intestinal L-cells. Meat, casein and vegetable-derived peptones (5 mg/ml), the L-amino acids Phe, Trp, Gln and Ala (20 mM each), and the dipeptide glycine-sarcosine (20 mM) stimulated GLP-1 secretion from primary cultures prepared from the small intestine. Further mechanistic studies were performed with meat peptone, and revealed the elevation of intracellular calcium in L-cells. Inhibition of the calcium sensing receptor (CaSR), transient receptor potential (TRP) channels and Q-type voltage gated calcium channels (VGCC) significantly attenuated peptone-stimulated GLP-1 release and reduced intracellular Ca2+ responses. CaSR inhibition also attenuated the GLP-1 secretory response to Gln. Targeting these pathways in L-cells could be used to increase endogenous production of GLP-1 and offer exploitable avenues for the development of therapeutics to treat diabetes and obesity. PMID:26215048

  7. Evaluation of a newly developed triple buffered peptone broth for detection of Salmonella in broiler feed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lactose broth (LB) and buffered peptone (BP) are used as pre-enrichment media to recover Salmonella from feed. Bacterial utilization of feed carbohydrates results in the production of acidic byproducts causing a drop in the media pH which can injure or kill Salmonella and yield false negative resul...

  8. The effect of alkaline earth metal ion dopants on photocatalytic water splitting by NaTaO(3) powder.

    PubMed

    Iwase, Akihide; Kato, Hideki; Kudo, Akihiko

    2009-01-01

    Alkaline earth metal ions (Ca, Sr, and Ba) are doped into a NaTaO(3) photocatalyst, yielding fine particles and surface structures with nanometer-scale "steps." The formation of the surface nanostep structure depends on the amount of doped Sr and Ba. The photocatalytic water splitting over NaTaO(3) is enhanced: NaTaO(3) doped with 0.5 and 1.0 mol % of Sr shows high activities for photocatalytic water splitting without loading of a co-catalyst, and the photocatalytic activity is further improved by loading with a NiO co-catalyst.

  9. Mechanism of oxygen reduction reaction on Pt(111) in alkaline solution: Importance of chemisorbed water on surface

    DOE PAGES

    Liu, Shizhong; White, Michael G.; Liu, Ping

    2016-06-30

    Here, we report a detailed mechanistic study of the oxygen reduction reaction (ORR) on Pt(111) in alkaline solution, combining density functional theory and kinetic Monte Carlo simulations. A complex reaction network including four possible pathways via either 2e– or 4e– transfer is established and is able to reproduce the experimental measured polarization curve at both low- and high-potential regions. Our results show that it is essential to account for solvation by water and the dynamic coverage of *OH to describe the reaction kinetics well. In addition, a chemisorbed water (*H2O)-mediated mechanism including 4e– transfers is identified, where the reduction stepsmore » via *H2O on the surface are potential-independent and only the final removal of *OH from the surface in the form of OH–(aq) contributes to the current. For the ORR in alkaline solutions, such a mechanism is more competitive than the associative and dissociative mechanisms typically used to describe the ORR in acid solution. Finally, *OH and **O2 intermediates are found to be critically important for tuning the ORR activity of Pt in alkaline solution. To enhance the activity, the binding of Pt should be tuned in such a way that *OH binding is weak enough to release more surface sites under working conditions, while **O2 binding is strong enough to enable the ORR via the 4e– transfer mechanism.« less

  10. Fish peptone development using enzymatic hydrolysis of silver carp by-products as a nitrogen source in Staphylococcus aureus media

    PubMed Central

    Fallah, Meysam; Bahram, Somayeh; Javadian, Seyed Roholla

    2015-01-01

    Fish peptone was produced using enzymatic hydrolysis of silver carp filleting by-products by alcalase and trypsin. Also, the efficiency of the hydrolysates as a nitrogen source in Staphylococcus aureus medium was compared with commercial TSB. The results indicated that the protein hydrolysate from alcalase and trypsin had high protein content (92.92%, 91.53 respectively), and degree of hydrolysis (4.94%, 4.6% respectively).The results showed that silver carp filleting waste can be an efficient source for fish peptone production as a nitrogen source for S. aureus medium. However, the type of the used proteolytic enzyme considerably affected the performance of the resulting peptone despite the same DH. Fish peptone produced by alcalese performed significantly (P < 0.05) better than commercial TSB as a media for the bacteria while the performance of the trypsin peptone was not as good as the commercial medium. PMID:25838893

  11. Molybdenum Carbide-Embedded Nitrogen-Doped Porous Carbon Nanosheets as Electrocatalysts for Water Splitting in Alkaline Media.

    PubMed

    Lu, Chenbao; Tranca, Diana; Zhang, Jian; Rodrı Guez Hernández, Fermı N; Su, Yuezeng; Zhuang, Xiaodong; Zhang, Fan; Seifert, Gotthard; Feng, Xinliang

    2017-03-20

    Molybdenum carbide (Mo2C) based catalysts were found to be one of the most promising electrocatalysts for hydrogen evolution reaction (HER) in acid media in comparison with Pt-based catalysts but were seldom investigated in alkaline media, probably due to the limited active sites, poor conductivity, and high energy barrier for water dissociation. In this work, Mo2C-embedded nitrogen-doped porous carbon nanosheets (Mo2C@2D-NPCs) were successfully achieved with the help of a convenient interfacial strategy. As a HER electrocatalyst in alkaline solution, Mo2C@2D-NPC exhibited an extremely low onset potential of ∼0 mV and a current density of 10 mA cm(-2) at an overpotential of ∼45 mV, which is much lower than the values of most reported HER electrocatalysts and comparable to the noble metal catalyst Pt. In addition, the Tafel slope and the exchange current density of Mo2C@2D-NPC were 46 mV decade(-1) and 1.14 × 10(-3) A cm(-2), respectively, outperforming the state-of-the-art metal-carbide-based electrocatalysts in alkaline media. Such excellent HER activity was attributed to the rich Mo2C/NPC heterostructures and synergistic contribution of nitrogen doping, outstanding conductivity of graphene, and abundant active sites at the heterostructures.

  12. Speciation of dissolved silicates in natural waters containing alkaline and alkaline-earth ions. A case study--waters from arid lands (North West China).

    PubMed

    Tanaka, Miho; Takahashi, Kazuya; Sahoo, Yu Vin

    2004-02-01

    The concentration of silica in water samples from the desert area of Xinjiang, N. W. China, has been measured by colorimetry with ammonium molybdate. The observed pattern of dependence of the concentration of silica on the concentration of sodium ion (Na(+)) in the water samples is consistent with the pattern obtained by experiments on in-vitro dissolution of silica gel in sodium chloride (NaCl) solution. This indicates that the dissolution of silica in the hydrologic system in this area depends on the concentration of Na(+). Calcium ion (Ca(2+)), which is known to play an important role on the dissolution of silica on the basis of in-vitro experiments, was observed to take little part in the dissolution of silica in actual natural water samples. This implies that the Ca(2+) is bound to the hydrogen carbonate anion or that the Ca(2+) content of natural water containing salts is very low, owing to precipitation. In these samples silicate-Na(+) was identified as the dissolution species of silica; it was also ascertained that Ca(2+) did not form complexes with silicate species. These observations resulted from direct identification of dissolved chemical species by use of FAB-MS (fast atom bombardment mass spectrometry). The research indicates that in water samples in this critically arid region the concentration of "dissolved" silica is basically determined by the concentration of Na(+), indicative of pure inorganic conditions in the desert area of Xinjiang, N.W. China.

  13. Facile synthesis of water-soluble carbon nano-onions under alkaline conditions.

    PubMed

    Ahmed, Gaber Hashem Gaber; Laíño, Rosana Badía; Calzón, Josefa Angela García; García, Marta Elena Díaz

    2016-01-01

    Carbonization of tomatoes at 240 °C using 30% (w/v) NaOH as catalyst produced carbon onions (C-onions), while solely carbon dots (C-dots) were obtained at the same temperature in the absence of the catalyst. Other natural materials, such as carrots and tree leaves (acer saccharum), under the same temperature and alkaline conditions did not produce carbon onions. XRD, FTIR, HRTEM, UV-vis spectroscopy, and photoluminescence analyses were performed to characterize the as-synthesized carbon nanomaterials. Preliminary tests demonstrate a capability of the versatile materials for chemical sensing of metal ions. The high content of lycopene in tomatoes may explain the formation of C-onions in alkaline media and a possible formation mechanism for such structures was outlined.

  14. Facile synthesis of water-soluble carbon nano-onions under alkaline conditions

    PubMed Central

    Ahmed, Gaber Hashem Gaber; Laíño, Rosana Badía; Calzón, Josefa Angela García

    2016-01-01

    Summary Carbonization of tomatoes at 240 °C using 30% (w/v) NaOH as catalyst produced carbon onions (C-onions), while solely carbon dots (C-dots) were obtained at the same temperature in the absence of the catalyst. Other natural materials, such as carrots and tree leaves (acer saccharum), under the same temperature and alkaline conditions did not produce carbon onions. XRD, FTIR, HRTEM, UV–vis spectroscopy, and photoluminescence analyses were performed to characterize the as-synthesized carbon nanomaterials. Preliminary tests demonstrate a capability of the versatile materials for chemical sensing of metal ions. The high content of lycopene in tomatoes may explain the formation of C-onions in alkaline media and a possible formation mechanism for such structures was outlined. PMID:27335764

  15. Use of solid phase extraction for the sequential injection determination of alkaline phosphatase activity in dynamic water systems.

    PubMed

    Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

    2012-08-30

    In this work, a solid phase extraction sequential injection methodology for the determination of alkaline phosphatase activity in dynamic water systems was developed. The determination of the enzymatic activity was based on the spectrophotometric detection of a coloured product, p-nitrophenol, at 405 nm. The p-nitrophenol is the product of the catalytic decomposition of p-nitrophenyl phosphate, a non-coloured substrate. Considering the low levels expected in natural waters and exploiting the fact of alkaline phosphatase being a metalloprotein, the enzyme was pre-concentrated in-line using a NTA Superflow resin charged with Zn(2+) ions. The developed sequential injection method enabled a quantification range of 0.044-0.441 unit mL(-1) of enzyme activity with a detection limit of 0.0082 unit mL(-1) enzyme activity (1.9 μmol L(-1) of pNP) and a determination rate of 17 h(-1). Recovery tests confirmed the accuracy of the developed sequential injection method and it was effectively applied to different natural waters and to plant root extracts.

  16. The MCVD synthesis and characterization of water tolerant fiber optic waveguides based on alkaline earth-doped silicas

    NASA Astrophysics Data System (ADS)

    Farley, Kevin F.

    Optical fibers that transmit throughout the entire telecommunications spectrum (1.2--1.7 mum) are presently manufactured by the removal of hydrogen or OH from the host preform glass. Hydrogen-oxygen torches are utilized in the conventional preform manufacturing process, but result in the formation of hydroxyls in germanium-doped silica fiber. The hydroxyl species generate unacceptably high losses for long haul telecommunications systems. This thesis has explored an alternative strategy for reducing OH-related absorption in silica-based glasses. Alkaline earth modifiers have been introduced via the modified chemical vapor deposition (MCVD) process to successfully damp out and dramatically reduce the extrinsic attenuation associated with both water and hydrogen. Specifically, alkaline earth ions were introduced into alumino-silicate glasses to form MgO-Al2O3-SiO2, CaO-Al 2O3-SiO2, and SrO-Al2O3-SiO 2 compositions. The utilization of halide precursors based on the vapor delivery of rare earths was incorporated into the existing MCVD set-up to fabricate these optical preforms. Both the bulk preforms and fibers drawn from them were characterized to determine relevant optical properties, including the attenuation, index profiles and extinction coefficients arising from OH in each host. The data indicate that modification of the silica glass structure through the additions of modifying ions can significantly reduce OH related absorption. For example, the doping of alkaline earth ions decreased the extinction coefficient measured at the 1.39 mum) OH overtone, to values < 0.2 L/(mol*cm). Prompt gamma activation analysis (PGAA) measurements conducted at the National Institute of Standards and Technology (NIST) found OH concentrations in the glasses in the range from 10 to 27.5 ppm. The alkaline earth-doped fibers exhibited lower OH absorption at 1.39 mum) than germanium and aluminum-doped reference fibers. Fibers doped with either magnesium, calcium or strontium displayed up

  17. Mechanism of oxygen reduction reaction on Pt(111) in alkaline solution: Importance of chemisorbed water on surface

    SciTech Connect

    Liu, Shizhong; White, Michael G.; Liu, Ping

    2016-06-30

    Here, we report a detailed mechanistic study of the oxygen reduction reaction (ORR) on Pt(111) in alkaline solution, combining density functional theory and kinetic Monte Carlo simulations. A complex reaction network including four possible pathways via either 2e or 4e transfer is established and is able to reproduce the experimental measured polarization curve at both low- and high-potential regions. Our results show that it is essential to account for solvation by water and the dynamic coverage of *OH to describe the reaction kinetics well. In addition, a chemisorbed water (*H2O)-mediated mechanism including 4e transfers is identified, where the reduction steps via *H2O on the surface are potential-independent and only the final removal of *OH from the surface in the form of OH(aq) contributes to the current. For the ORR in alkaline solutions, such a mechanism is more competitive than the associative and dissociative mechanisms typically used to describe the ORR in acid solution. Finally, *OH and **O2 intermediates are found to be critically important for tuning the ORR activity of Pt in alkaline solution. To enhance the activity, the binding of Pt should be tuned in such a way that *OH binding is weak enough to release more surface sites under working conditions, while **O2 binding is strong enough to enable the ORR via the 4e transfer mechanism.

  18. Influence of alkalinity, hardness and dissolved solids on drinking water taste: A case study of consumer satisfaction.

    PubMed

    Lou, Jie-Chung; Lee, Wei-Li; Han, Jia-Yun

    2007-01-01

    Two surveys of consumer satisfaction with drinking water conducted by Taiwan Water Supply Corp. are presented in this study. The study results show that although a lot of money was invested to modify traditional treatment processes, over 60% of local residents still avoided drinking tap water. Over half of the respondents felt that sample TT (from the traditional treatment process) was not a good drinking water, whether in the first or second survey, whereas almost 60% of respondents felt that samples PA, PB, CCL and CT (from advanced treatment processes) were good to drink. For all drinking water samples, respondent satisfaction with a sample primarily depended on it having no unpleasant flavors. Taiwan Environmental Protection Administration plans to revise the drinking water quality standards for TH and TDS in the near future. The new standards require a lower TH concentration (from currently 400mg/L (as CaCO(3)) to 150mg/L (as CaCO(3))), and a lower TDS maximum admissible concentration from the current guideline of 600 to 250mg/L. Therefore, this study also evaluated the impacts on drinking water tastes caused by variations in TH and TDS concentrations, and assessed the need to issue more strict drinking water quality standards for TH and TDS. The research results showed that most respondents could not tell the difference in water taste among water samples with different TDS, TH and alkalinity. Furthermore, hardness was found to be inversely associated with cardiovascular diseases and cancers, and complying with more strict standards would lead most water facilities to invest billions of dollars to upgrade their treatment processes. Consequently, in terms of drinking water tastes alone, this study suggested that Taiwan Environmental Protection Administration should conduct more thorough reviews of the scientific literature that provides the rationale for setting standards and reconsider if it is necessary to revise drinking water quality standards for TH and

  19. Pitting Corrosion of Copper in Waters with High pH and Low Alkalinity

    EPA Science Inventory

    Localized or pitting corrosion of copper pipes used in household drinking-water plumbing is a problem for many water utilities and their customers. Extreme attack can lead to pinhole water leaks that may result in water damage, mold growth, and costly repairs. Water quality has b...

  20. Electrochemical Deposition and Characterization of Ni-Mo Alloys as Cathode for Alkaline Water Electrolysis

    NASA Astrophysics Data System (ADS)

    Manazoğlu, Mert; Hapçı, Gökçe; Orhan, Gökhan

    2016-01-01

    In this study, Ni-Mo alloy coatings were electrochemically deposited on a copper plate in citrate solutions. The effects of Ni/Mo mole ratio in the electrolyte and pH value on hydrogen evolution reaction (HER) as well as the electrochemical stability were investigated in the alkaline solution for electrodeposited NiMo. The electrocatalytic activity of the fabricated NiMo alloys for HER in alkaline solutions was investigated by the polarization measurements and electrochemical impedance spectroscopy techniques. The morphology and chemical composition of the electrodeposited Ni-Mo were investigated using SEM and EDS analyses. It was found that NiMo electrode with the highest molybdenum content (ca. 38 wt.%) and high surface area show high electrocatalytic activity in the HER. This was produced from a bath with a pH of 9.5, Ni/Mo ratio of 1/10 and 0.5 M sodium citrate concentration. The stability of this coating was tested by polarization measurements after different anodic and cathodic treatment in 1 M NaOH solution. The open circuit potential ( E ocp) of the electrode as a function of immersion time was also measured.

  1. Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping.

    PubMed

    Borrega, Marc; Tolonen, Lasse K; Bardot, Fanny; Testova, Lidia; Sixta, Herbert

    2013-05-01

    The potential of hot water extraction of birch wood to produce highly purified dissolving pulp in a subsequent soda-anthraquinone pulping process was evaluated. After intermediate extraction intensities, pulps with low xylan content (3-5%) and high cellulose yield were successfully produced. Increasing extraction intensity further decreased the xylan content in pulp. However, below a xylan content of 3%, the cellulose yield dramatically decreased. This is believed to be due to cleavage of glycosidic bonds in cellulose during severe hot water extractions, followed by peeling reactions during alkaline pulping. Addition of sodium borohydride as well as increased anthraquinone concentration in the pulping liquor increased the cellulose yield, but had no clear effects on pulp purity and viscosity. The low intrinsic viscosity of pulps produced after severe extraction intensities and soda-anthraquinone pulping corresponded to the viscosity at the leveling-off degree of polymerization, suggesting that nearly all amorphous cellulose had been degraded.

  2. Irrigation water acidification to neutralize alkalinity for nursery crop production: Substrate pH, electrical conductivity, and nutrient concentrations; and plant nutrition and growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Liming agents (LA) in irrigation water, typically associated with carbonates and bicarbonates of calcium (Ca) and magnesium (Mg), contribute to water alkalinity. Repeated application of LA to container crops can cause media-solution pH to rise overtime, that uncorrected, can lead to a nutrient avail...

  3. Effect of Strongly Alkaline Electrolyzed Water on Silk Degumming and the Physical Properties of the Fibroin Fiber

    PubMed Central

    Cao, Ting-Ting; Wang, Yuan-Jing; Zhang, Yu-Qing

    2013-01-01

    Strongly alkaline electrolyzed water (SAEW) was prepared by electrolysis of tap water in a laboratory-made water electrolyzer. The pH of stored SAEW was stable for more than one month. The hardness of the electrolyzed water was 30% lower and the Na+ concentration was 18% higher than those of the tap water. Silkworm cocoon shells were boiled in pH 11.50 SAEW at a ratio of 1∶40∼80 (W/V) for 20 min and the sericin layers around the silk fibroin fibers were removed completely. The tensile properties and thermal decomposition temperature of a single filament of silk fibroin obtained by the SAEW method were almost the same as those for the fiber obtained by the neutral soap, and much higher than those for the fiber obtained by Na2CO3 degumming. The results demonstrate that SAEW is an environmentally friendly and pollution-free silk degumming agent that allows highly efficient, low cost recovery of sericin. PMID:23824061

  4. SOLVING COPPER CORROSION PROBLEMS WHILE MAINTAINING LEAD CONTROL IN A HIGH ALKALINITY WATER USING ORTHOPHOSPHATE

    EPA Science Inventory

    Lead and Copper Rule sampling in 1992 uncovered high copper levels in many homes in the Indian Hill Water Works, Ohio (IHWW) water system. The 90th percentile copper and lead levels were 1.63 mg/L and 0.012 mg/L, respectively. IHWW supplies water to several suburban communities t...

  5. Oxygen evolution reaction characteristics of synthetic nickel-cobalt-oxide electrodes for alkaline anion-exchange membrane water electrolysis

    NASA Astrophysics Data System (ADS)

    Koo, Tae Woo; Park, ChanSu; Kim, Yang Do; Lee, Dooyong; Park, Sungkyun; Lee, Jae Ho; Choi, Sung Mook; Choi, Chul Young

    2015-11-01

    A polymer electrolyte membrane water electrolysis system can produce high-purity hydrogen gases in a highly efficient manner. However, the level of hydrogen gas production is still small. In addition, noble-metal catalysts for the reaction in acidic environments, as well as an additional drying step to remove water contained in the hydrogen, are required. Therefore, water electrolysis system with high efficiency and lower cost, an alkaline anion-exchange membrane system that can produce high-purity hydrogen without a noble-metal catalyst, is needed. Nano-size NiCo2O4 powders were prepared by using a sol-gel method to achieve an efficient and economical water electrolysis system. When the powder was calcined at 450 °C, the crystallinity and the cyclic voltammogram measurement showed the best values. In addition, the 15-wt.% polytetrafluoroethylene mixed NiCo2O4 powders exhibited the largest cyclic voltammetry active area and the highest oxygen evolution reaction activity with the appropriate stability.

  6. Water miscible mono alcohols' effect on the proteolytic performance of Bacillus clausii serine alkaline protease.

    PubMed

    Duman, Yonca Avci; Kazan, Dilek; Denizci, Aziz Akin; Erarslan, Altan

    2014-01-01

    In this study, our investigations showed that the increasing concentrations of all examined mono alcohols caused a decrease in the Vm, kcat and kcat/Km values of Bacillus clausii GMBE 42 serine alkaline protease for casein hydrolysis. However, the Km value of the enzyme remained almost the same, which was an indicator of non-competitive inhibition. Whereas inhibition by methanol was partial non-competitive, inhibition by the rest of the alcohols tested was simple non-competitive. The inhibition constants (KI) were in the range of 1.32-3.10 M, and the order of the inhibitory effect was 1-propanol>2-propanol>methanol>ethanol. The ΔG(≠) and ΔG(≠)E-T values of the enzyme increased at increasing concentrations of all alcohols examined, but the ΔG(≠)ES value of the enzyme remained almost the same. The constant Km and ΔG(≠)ES values in the presence and absence of mono alcohols indicated the existence of different binding sites for mono alcohols and casein on enzyme the molecule. The kcat of the enzyme decreased linearly by increasing log P and decreasing dielectric constant (D) values, but the ΔG(≠) and ΔG(≠)E-T values of the enzyme increased by increasing log P and decreasing D values of the reaction medium containing mono alcohols.

  7. Reactivity of alkaline lignite fly ashes towards CO2 in water.

    PubMed

    Back, Martin; Kuehn, Michael; Stanjek, Helge; Peiffer, Stefan

    2008-06-15

    The reaction kinetics between alkaline lignite fly ashes and CO2 (pCO2 = 0.01--0.03 MPa)were studied in a laboratory CO2 flow-through reactor at 25--75 degrees C. The reaction is characterized by three phases that can be separated according to the predominating buffering systems and the rates of CO2 uptake. Phase I (pH > 12, < 30 min) is characterized by the dissolution of lime, the onset of calcite precipitation and a maximum uptake, the rate of which seems to be limited by dissolution of CO2. Phase II (pH < 10.5, 10--60 min) is dominated by the carbonation reaction. CO2 uptake in phase III (pH < 8.3) is controlled by the dissolution of periclase (MgO) leading to the formation of dissolved magnesium-bicarbonate. Phase I could be significantly extended by increasing the solid-liquid ratios and temperature, respectively. At 75 degrees C the rate of calcite precipitation was doubled leading to the neutralization of approximately 0.23 kg CO2 per kg fly ash within 4.5 h, which corresponds to nearly 90% of the total acid neutralizing capacity.

  8. Reactivity of alkaline lignite fly ashes towards CO{sub 2} in water

    SciTech Connect

    Martin Back; Michael Kuehn; Helge Stanjek; Stefan Peiffer

    2008-06-15

    The reaction kinetics between alkaline lignite fly ashes and CO{sub 2} (pCO{sub 2} = 0.01-0.03 MPa) were studied in a laboratory CO{sub 2} flow-through reactor at 25-75{sup o}C. The reaction is characterized by three phases that can be separated according to the predominating buffering systems and the rates of CO{sub 2} uptake. Phase I (pH > 12, < 30 min) is characterized by the dissolution of lime, the onset of calcite precipitation and a maximum uptake, the rate of which seems to be limited by dissolution of CO{sub 2}. Phase II (pH < 10.5, 10-60 min) is dominated by the carbonation reaction. CO{sub 2} uptake in phase III (pH < 8.3) is controlled by the dissolution of periclase (MgO) leading to the formation of dissolved magnesium-bicarbonate. Phase I could be significantly extended by increasing the solid-liquid ratios and temperature, respectively. At 75{sup o}C the rate of calcite precipitation was doubled leading to the neutralization of approximately 0.23 kg CO{sub 2} per kg fly ash within 4.5 h, which corresponds to nearly 90% of the total acid neutralizing capacity. 21 refs., 5 figs., 1 tab.

  9. Calcium Carbonate Nucleation in an Alkaline Lake Surface Water, Pyramid Lake, Nevada, USA

    USGS Publications Warehouse

    Reddy, M.M.; Hoch, A.

    2012-01-01

    Calcium concentration and calcite supersaturation (??) needed for calcium carbonate nucleation and crystal growth in Pyramid Lake (PL) surface water were determined during August of 1997, 2000, and 2001. PL surface water has ?? values of 10-16. Notwithstanding high ??, calcium carbonate growth did not occur on aragonite single crystals suspended PL surface water for several months. However, calcium solution addition to PL surface-water samples caused reproducible calcium carbonate mineral nucleation and crystal growth. Mean PL surface-water calcium concentration at nucleation was 2.33 mM (n = 10), a value about nine times higher than the ambient PL surface-water calcium concentration (0.26 mM); mean ?? at nucleation (109 with a standard deviation of 8) is about eight times the PL surface-water ??. Calcium concentration and ?? regulated the calcium carbonate formation in PL nucleation experiments and surface water. Unfiltered samples nucleated at lower ?? than filtered samples. Calcium concentration and ?? at nucleation for experiments in the presence of added particles were within one standard deviation of the mean for all samples. Calcium carbonate formation rates followed a simple rate expression of the form, rate (mM/min) = A (??) + B. The best fit rate equation "Rate (?? mM/?? min) = -0.0026 ?? + 0.0175 (r = 0.904, n = 10)" was statistically significant at greater than the 0.01 confidence level and gives, after rearrangement, ?? at zero rate of 6.7. Nucleation in PL surface water and morphology of calcium carbonate particles formed in PL nucleation experiments and in PL surface-water samples suggest crystal growth inhibition by multiple substances present in PL surface water mediates PL calcium carbonate formation, but there is insufficient information to determine the chemical nature of all inhibitors. ?? 2011 U.S. Government.

  10. Calcium carbonate nucleation in an alkaline lake surface water, Pyramid Lake, Nevada, USA

    USGS Publications Warehouse

    Reddy, Michael M.; Hoch, Anthony

    2012-01-01

    Calcium concentration and calcite supersaturation (Ω) needed for calcium carbonate nucleation and crystal growth in Pyramid Lake (PL) surface water were determined during August of 1997, 2000, and 2001. PL surface water has Ω values of 10-16. Notwithstanding high Ω, calcium carbonate growth did not occur on aragonite single crystals suspended PL surface water for several months. However, calcium solution addition to PL surface-water samples caused reproducible calcium carbonate mineral nucleation and crystal growth. Mean PL surface-water calcium concentration at nucleation was 2.33 mM (n = 10), a value about nine times higher than the ambient PL surface-water calcium concentration (0.26 mM); mean Ω at nucleation (109 with a standard deviation of 8) is about eight times the PL surface-water Ω. Calcium concentration and Ω regulated the calcium carbonate formation in PL nucleation experiments and surface water. Unfiltered samples nucleated at lower Ω than filtered samples. Calcium concentration and Ω at nucleation for experiments in the presence of added particles were within one standard deviation of the mean for all samples. Calcium carbonate formation rates followed a simple rate expression of the form, rate (mM/min) = A (Ω) + B. The best fit rate equation "Rate (Δ mM/Δ min) = -0.0026 Ω + 0.0175 (r = 0.904, n = 10)" was statistically significant at greater than the 0.01 confidence level and gives, after rearrangement, Ω at zero rate of 6.7. Nucleation in PL surface water and morphology of calcium carbonate particles formed in PL nucleation experiments and in PL surface-water samples suggest crystal growth inhibition by multiple substances present in PL surface water mediates PL calcium carbonate formation, but there is insufficient information to determine the chemical nature of all inhibitors.

  11. Enhanced production of prodigiosin by Serratia marcescens MO-1 using ram horn peptone.

    PubMed

    Kurbanoglu, Esabi Basaran; Ozdal, Murat; Ozdal, Ozlem Gur; Algur, Omer Faruk

    2015-06-01

    This work addresses the production of prodigiosin from ram horn peptone (RHP) using MO-1, a local isolate in submerged culture. First, a novel gram-negative and rod-shaped bacterial strain, MO-1, was isolated from the body of the grasshopper (Poecilemon tauricola Ramme 1951), which was collected from pesticide-contaminated fields. Sequence analysis of 16S rDNA classified the microbe as Serratia marcescens. The substrate utilization potential (BIOLOG) and fatty acid methyl ester profile (FAME) of S. marcescens were also determined. The effect of RHP on the production of prodigiosin by S. marcescens MO-1 was investigated, and the results showed that RHP supplementation promoted the growth of MO-1 and increased the production of prodigiosin. A concentration of 0.4% (w/v) RHP resulted in the greatest yield of prodigiosin (277.74 mg/L) after 48 h when mannitol was used as the sole source of carbon. The pigment yield was also influenced by the types of carbon sources and peptones. As a result, RHP was demonstrated to be a suitable substrate for prodigiosin production. These results revealed that prodigiosin could be produced efficiently by S. marcescens using RHP.

  12. Relationships between testate amoeba communities and water quality in Lake Donghu, a large alkaline lake in Wuhan, China

    NASA Astrophysics Data System (ADS)

    Qin, Yangmin; Fournier, Bertrand; Lara, Enrique; Gu, Yansheng; Wang, Hongmei; Cui, Yongde; Zhang, Xiaoke; Mitchell, Edward A. D.

    2013-06-01

    The middle Yangtze Reach is one of the most developed regions of China. As a result, most lakes in this area have suffered from eutrophication and serious environmental pollution during recent decades. The aquatic biodiversity in the lakes of the area is thus currently under significant threat from continuous human activities. Testate amoebae (TA) are benthic (rarely planktonic) microorganisms characterized by an agglutinated or autogenous shell. Owing to their high abundance, preservation potential in lacustrine sediments, and distinct response to environmental stress, they are increasingly used as indicators for monitoring water quality and reconstructing palaeoenvironmental changes. However this approach has not yet been developed in China. This study presents an initial assessment of benthic TA assemblages in eight lakes of Lake Donghu in the region of Wuhan, China. Testate amoeba community structure was most strongly correlated to water pH. In more alkaline conditions, communities were dominated by Centropyxis aculeata, Difflugia oblonga, Pontigulasia compressa, Pon. elisa and Lesquereusia modesta. These results are consistent with previous studies and show that TA could be useful for reconstructing past water pH fluctuations in China. To achieve this, the next step will be to expand the database and build transfer function models.

  13. Morphological characterization of viruses in the stratified water column of alkaline, hypersaline Mono Lake.

    PubMed

    Brum, Jennifer R; Steward, Grieg F

    2010-10-01

    Concentrations of viruses and prokaryotes in the alkaline, moderately hypersaline, seasonally stratified Mono Lake are among the highest reported for a natural aquatic environment. We used electron microscopy to test whether viral morphological characteristics differed among the epilimnion, metalimnion, and the anoxic hypolimnion of the lake and to determine how the properties of viruses in Mono Lake compare to other aquatic environments. Viral capsid size distributions were more similar in the metalimnion and hypolimnion of Mono Lake, while viral tail lengths were more similar in the epilimnion and metalimnion. The percentage of tailed viruses decreased with depth and the relative percentages of tailed phage families changed with depth. The presence of large (>125 nm capsid), untailed viruses in the metalimnion and hypolimnion suggests that eukaryotic viruses are produced in these suboxic and anoxic, hypersaline environments. Capsid diameters of viruses were larger on average in Mono Lake compared to other aquatic environments, and no lemon-shaped or filamentous viruses were found, in contrast to other high-salinity or high-altitude lakes and seas. Our data suggest that the physically and chemically distinct layers of Mono Lake harbor different viral assemblages, and that these assemblages are distinct from other aquatic environments that have been studied. Furthermore, we found that filtration of a sample through a 0.22-µm pore-size filter significantly altered the distribution of viral capsid diameters and tail lengths, resulting in a relative depletion of viruses having larger capsids and longer tails. This observation highlights the potential for bias in molecular surveys of viral diversity, which typically rely on filtration through 0.2- or 0.22-µm pore-size membrane filters to remove bacteria during sample preparation.

  14. Fractionation of oil palm frond hemicelluloses by water or alkaline impregnation and steam explosion.

    PubMed

    Sabiha-Hanim, Saleh; Mohd Noor, Mohd Azemi; Rosma, Ahmad

    2015-01-22

    Steam explosion of oil palm frond has been carried out under different temperatures between 180 and 210°C for 4 min (severity of 2.96-3.84) after impregnation of the frond chips with water or KOH solution. The effects of impregnation and steam explosion conditions of oil palm fronds on the water soluble fraction and insoluble fraction were investigated. The maximum yield of hemicelluloses in water soluble fractions recovered was 23.49% and 25.33% for water and KOH impregnation, treated with steam explosion at temperature of 210°C (severity of 3.84) with a fractionation efficiency of 77.30% and 83.32%, respectively. Under this condition, the water insoluble fractions contained celluloses at 60.83% and 64.80% for water and KOH impregnation, respectively. The steam explosion temperature of 210°C for 4 min (logR(o) 3.84) was found to be the best condition in the extraction of hemicelluloses from OPF for both types of impregnation.

  15. Quaternized poly (styrene-co-vinylbenzyl chloride) anion exchange membranes for alkaline water electrolysers

    NASA Astrophysics Data System (ADS)

    Vengatesan, S.; Santhi, S.; Jeevanantham, S.; Sozhan, G.

    2015-06-01

    In this study, poly (ST-co-VBC) based anion exchange membranes with different styrene to VBC ratios (1: 0.16, 1: 0.33 and 1: 1) have been prepared via chloromethylation-free synthetic route using aromatic vinyl monomers. The synthesized co-polymers are identified by FTIR and 1H-NMR analysis. Hydroxide (OH-) ion conductivity of the anion exchange membrane with styrene to VBC ratio of 1: 0.33 is as high as 6.8 × 10-3 S cm-1 in de-ionised water at 25 °C. The membrane also acquires the ion-exchange capacity of 2.14 meq. g-1, and the water uptake of 127%. Membrane-electrode-assembly (MEA) using the anion exchange membrane and Ni - foam catalyst demonstrate the current density of 40 mA cm-2 at 2.3 V in a water electrolyser cell.

  16. Surface analysis and depth profiling of corrosion products formed in lead pipes used to supply low alkalinity drinking water.

    PubMed

    Davidson, C M; Peters, N J; Britton, A; Brady, L; Gardiner, P H E; Lewis, B D

    2004-01-01

    Modern analytical techniques have been applied to investigate the nature of lead pipe corrosion products formed in pH adjusted, orthophosphate-treated, low alkalinity water, under supply conditions. Depth profiling and surface analysis have been carried out on pipe samples obtained from the water distribution system in Glasgow, Scotland, UK. X-ray diffraction spectrometry identified basic lead carbonate, lead oxide and lead phosphate as the principal components. Scanning electron microscopy/energy-dispersive x-ray spectrometry revealed the crystalline structure within the corrosion product and also showed spatial correlations existed between calcium, iron, lead, oxygen and phosphorus. Elemental profiling, conducted by means of secondary ion mass spectrometry (SIMS) and secondary neutrals mass spectrometry (SNMS) indicated that the corrosion product was not uniform with depth. However, no clear stratification was apparent. Indeed, counts obtained for carbonate, phosphate and oxide were well correlated within the depth range probed by SIMS. SNMS showed relationships existed between carbon, calcium, iron, and phosphorus within the bulk of the scale, as well as at the surface. SIMS imaging confirmed the relationship between calcium and lead and suggested there might also be an association between chloride and phosphorus.

  17. The Effect of Orthophosphate as a Copper Corrosion Inhibitor in High Alkalinity Drinking Water Systems

    DTIC Science & Technology

    2007-03-01

    the cold-water sample faucet was turned on for one minute. The faucet was turned off, then dried with a paper towel . D. The LDPE sample collection...Sussex, England: Ellis Horwood, 1989. McClave, James T., Benson, P. George, and Sincich, Terry . Statistics for Business and Economics, 9th Edition

  18. Recent progress on earth abundant hydrogen evolution reaction and oxygen evolution reaction bifunctional electrocatalyst for overall water splitting in alkaline media

    NASA Astrophysics Data System (ADS)

    Jamesh, Mohammed Ibrahim

    2016-11-01

    Electrochemical water-splitting is one of the promising ways for producing clean chemical fuel (Hydrogen) while cheap-earth-abundant-bifunctional-electrocatalyst is one of the possible way for improving the overall cost efficiency of water-splitting. This paper reviews the chemical state, hydrogen and oxygen evolution reaction activity in alkaline media, overall water-splitting performance in alkaline media, stability, and possible-factors for improving its efficiency of various kinds of recently reported electrocatalyst such as Ni-P, Co-P, Ni-Co-P, graphene-Co-P, O/N/C-Co/Ni, Ni-S, B-Ni/Co, Ni-Co, Mo, Se, Fe, Mn/Zn/Ti, and metal-free based earth-abundant-bifunctional-electrocatalyst. This paper also reviews and highlights the remarkable water splitting performance of the earth-abundant-bifunctional-electrocatalyst those exhibit better or well comparable with Pt/C//RuO2.

  19. Changes in the water quality and bacterial community composition of an alkaline and saline oxbow lake used for temporary reservoir of geothermal waters.

    PubMed

    Borsodi, Andrea K; Szirányi, Barbara; Krett, Gergely; Márialigeti, Károly; Janurik, Endre; Pekár, Ferenc

    2016-09-01

    Geothermal waters exploited in the southeastern region of Hungary are alkali-hydrogen-carbonate type, and beside the high amount of dissolved salt, they contain a variety of aromatic, heteroaromatic, and polyaromatic hydrocarbons. The majority of these geothermal waters used for heating are directed into surface waters following a temporary storage in reservoir lakes. The aim of this study was to gain information about the temporal and spatial changes of the water quality as well as the bacterial community composition of an alkaline and saline oxbow lake operated as reservoir of used geothermal water. On the basis of the water physical and chemical measurements as well as the denaturing gradient gel electrophoresis (DGGE) patterns of the bacterial communities, temporal changes were more pronounced than spatial differences. During the storage periods, the inflow, reservoir water, and sediment samples were characterized with different bacterial community structures in both studied years. The 16S ribosomal RNA (rRNA) gene sequences of the bacterial strains and molecular clones confirmed the differences among the studied habitats. Thermophilic bacteria were most abundant in the geothermal inflow, whereas the water of the reservoir was dominated by cyanobacteria and various anoxygenic phototrophic prokaryotes. In addition, members of several facultative anaerobic denitrifying, obligate anaerobic sulfate-reducing and syntrophic bacterial species capable of decomposition of different organic compounds including phenols were revealed from the water and sediment of the reservoir. Most of these alkaliphilic and/or halophilic species may participate in the local nitrogen and sulfur cycles and contribute to the bloom of phototrophs manifesting in a characteristic pink-reddish discoloration of the water of the reservoir.

  20. Effect of Morphology of Co3O4 for Oxygen Evolution Reaction in Alkaline Water Electrolysis

    PubMed Central

    Xu, Qi-Zhi; Xu, Qi-Zhi; Su, Yu-Zhi; Wu, Hao; Cheng, Hui; Hui, Yun-Ping; Li, Nan; Liu, Zhao-Qing

    2014-01-01

    In this paper, three different morphological Co3O4 electrodes for oxygen evolution reaction (OER) have been synthesized. By comparing the three morphologies of Co3O4, the electrocatalytic properties show that the urchin-like spheres of Co3O4 electrode has relative low overpotential and good electrocatalysis stability, indicating that the structure of urchin-like Co3O4 spheres exhibit an easy OER for water splitting. PMID:25525423

  1. Significant Effects Due to Peptone in Kelman Medium on Colony Characteristics and Virulence of Ralstonia solanacearum in Tomato

    PubMed Central

    Thomas, Pious; Upreti, Reshmi

    2014-01-01

    The study was taken up to assess if the media constituents played any role in governing the variable colony characteristics or pathogenicity of the bacterial wilt pathogen, Ralstonia solanacearum cultured on the widely employed Kelman medium. The effects due to the constituents 2,3,5-triphenyl tetrazolium chloride (TTC), peptone, casein hydrolysate and glucose on colony characteristics were investigated using -80°C stored culture of strain ‘NH-Av01’ (race 1, biovar 3) isolated from tomato. Comparing the pigment inducing TTC from two brands, its source or mode of storage/incorporation did not impart any significant effects. The source of peptone, on the other hand, displayed striking effects on the extent of colony growth, fluidity and red pigmentation depending on type, brand or batch / lot of manufacture as documented with 20 different formulations. Significant differences in the pathogenicity of isolate derived from different peptone sources in seedling-challenge assay on tomato were observed. The observations on peptone effects were endorsed with four other isolates belonging to distinct geographic locations, crops (eggplant, chilli, ginger) or races (race 1 or 4). The peptone source did not influence the pathogen-responses in biovar tests but notably altered the pattern of lawn formation and inhibition zone development during antagonistic assays. Casein hydrolysate displayed some variable effects while glucose source had no effect. This study brings to light the significant modifying effects by the peptone-constituent in Kelman medium on the physiology of R. solanacearum and the virulence of isolate and the need to consider the source of media components during culture maintenance, host-pathogen interaction studies or microbe-microbe interaction investigations. PMID:25408775

  2. The effect of water on the physical and thermodynamic properties of calc-alkaline basalt and basaltic andesite

    NASA Astrophysics Data System (ADS)

    Robert, G.; Whittington, A. G.; Stechern, A.; Behrens, H.

    2013-12-01

    We present corresponding viscosity and heat capacity data obtained on a series of hydrated glasses and supercooled melts for Fe-free calc-alkaline basaltic (sb, NBO/T = 0.67) and basaltic andesite analogues (sba, NBO/T = 0.40). Water contents range from nominally anhydrous to 3.76 wt.% H2O. Density measurements on relaxed (1 atm) hydrous glasses (post-viscometry) yield a partial molar volume of H2O of 12.9 and of 11.4 cm3mol-1 for sba and sb, respectively. Viscosity data were obtained at temperatures in the neighbourhood of the glass transition using the parallel-plate method, and at superliquidus temperatures using the concentric-cylinder and falling-sphere methods. The effect of water on viscosity is most dramatic at low temperatures, with the addition of ~2 wt.% H2O resulting in a reduction of the temperature at which the viscosity of the melt is 1012 Pa s (T12) of 170-180°C. The viscosity of a calc-alkaline basaltic andesite magma with 2 wt.% H2O at depth would increase by a factor of ~100 upon complete degassing during ascent. Calorimetric measurements were made with a Perkin-Elmer 8500 Differential Scanning Calorimeter up to 750°C, the limit of the instrument, depending on the sample water content. The increase in heat capacity associated with the transition from a glass to a supercooled liquid is on the order of ~25-30% and is higher in magnitude the more depolymerized the liquid. Our preliminary results suggest that the heat capacity of the hydrous sba and sb liquids decreases with increasing temperature immediately above the glass transition, similar to borosilicate and titanosilicate melts. In the anhydrous titano- and boro-silicate melts, this anomalous behaviour was linked to T-dependent mixing of B or Ti with Si. In sb and sba, the observed decrease in configurational heat capacity with increasing temperature may be related to the interplay of 'polymerizing' (viscosity-increasing) vs. 'depolymerizing' (viscosity-decreasing) solution mechanisms of

  3. Chabazite: stable cation-exchanger in hyper alkaline concrete pore water.

    PubMed

    Van Tendeloo, Leen; Wangermez, Wauter; Kurttepeli, Mert; de Blochouse, Benny; Bals, Sara; Van Tendeloo, Gustaaf; Martens, Johan A; Maes, André; Kirschhock, Christine E A; Breynaert, Eric

    2015-02-17

    To avoid impact on the environment, facilities for permanent disposal of hazardous waste adopt multibarrier design schemes. As the primary barrier very often consists of cement-based materials, two distinct aspects are essential for the selection of suitable complementary barriers: (1) selective sorption of the contaminants in the repository and (2) long-term chemical stability in hyperalkaline concrete-derived media. A multidisciplinary approach combining experimental strategies from environmental chemistry and materials science is therefore essential to provide a reliable assessment of potential candidate materials. Chabazite is typically synthesized in 1 M KOH solutions but also crystallizes in simulated young cement pore water, a pH 13 aqueous solution mainly containing K(+) and Na(+) cations. Its formation and stability in this medium was evaluated as a function of temperature (60 and 85 °C) over a timeframe of more than 2 years and was also asessed from a mechanistic point of view. Chabazite demonstrates excellent cation-exchange properties in simulated young cement pore water. Comparison of its Cs(+) cation exchange properties at pH 8 and pH 13 unexpectedly demonstrated an increase of the KD with increasing pH. The combined results identify chabazite as a valid candidate for inclusion in engineered barriers for concrete-based waste disposal.

  4. Predicting Gran alkalinity and calcium concentrations in river waters over a national scale using a novel modification to the G-BASH model.

    PubMed

    Cresser, Malcolm S; Ahmed, Nayan; Smart, Richard P; Arowolo, Toyin; Calver, Louise J; Chapman, Pippa J

    2006-09-01

    Monthly stream water calcium and Gran alkalinity concentration data from 11 sub-catchments of the Nether Beck in the English Lake District have been used to appraise the transferability of the Scottish, River Dee-based G-BASH model. Readily available riparian zone geochemistry and flow paths were used initially to predict minimum and mean stream water concentrations at the Nether Beck, based on calibration equations from the River Dee catchment data. Predicted values significantly exceeded observed values. Differences in runoff between the two areas, leading to a dilution effect in the Nether Beck, explained most of the difference between observed and predicted values. Greater acid deposition in the Lake District also reduced stream water Gran alkalinity concentrations in that area. If regional differences in precipitation, evapotranspiration and pollutant deposition are incorporated into the model, it may then be used reliably to predict catchment susceptibility to acidification over a wide regional (national) scale.

  5. Phase transformation of the brownmillerite SrCoO2.5 thin film through alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Tambunan, Octolia Togibasa; Lee, Min Young; Kim, Deok Hyeon; Parwanta, Kadek Juliana; Jung, Chang Uk

    2014-06-01

    A phase transformation from insulating brownmillerite SrCoO2.5 to conducting perovskite SrCoO3 through electrochemical oxidation has been demonstrated for thin films of SrCoOx on a SrTiO3 (001) substrate. The cobalt-oxide film strongly favors the brownmillerite phase of SrCoO2.5 instead of the perovskite phase of SrCoO3 on a SrTiO3 (001) substrate due to its low lattice mismatch. Therefore, the phase transformation has its own retention. The alkaline water electrolysis occurs between the copper cathode and the SrCoO2.5 film anode. The H+ ions are attracted to the cathode and generate H2 gas. The OH- ions are attracted to the film's surface and generate a rich amount of oxygen to fill the oxygen vacancy channel of brownmillerite SrCoO2.5. The phase transformation was verified from the change in the out-of-plane lattice constant and the change in the resistivity of the electrolyzed film.

  6. Electrodeposition of Sn-Ni Alloy Coatings for Water-Splitting Application from Alkaline Medium

    NASA Astrophysics Data System (ADS)

    Shetty, Sandhya; Hegde, A. Chitharanjan

    2017-02-01

    In this work, Sn-Ni alloy coatings were developed onto the surface of copper from a newly formulated electrolytic bath by a simple and cost-effective electrodeposition technique using gelatin as an additive. The electrocatalytic behavior of coatings deposited at different current densities (c.d.'s) for water-splitting applications, in terms of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), has been researched. The experimental results showed that the electrocatalytic activity of Sn-Ni coatings has a close relationship with its composition, surface morphology, and phase structure depending on the c.d. used, supported by scanning electron microscopy (SEM-EDX) and X-ray diffraction (XRD) analyses. Cyclic voltammetry and chronopotentiometry techniques have demonstrated that Sn-Ni alloy deposited at 4.0 A dm-2 (having 37.6 wt pct Ni) and 1.0 A dm-2 (having 19.6 wt pct Ni) exhibit, respectively, the highest electrocatalytic behavior for HER and OER in 1.0-M KOH solution. Sn-Ni alloy coatings were found to be stable under working conditions of electrolysis, confirmed by electrochemical corrosion tests. High electrocatalytic activity of Sn-Ni alloy coatings for both HER and OER is specific to their composition, surface morphology, and active surface area.

  7. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water

    USGS Publications Warehouse

    Patton, Charles J.; Kryskalla, Jennifer R.

    2003-01-01

    Alkaline persulfate digestion was evaluated and validated as a more sensitive, accurate, and less toxic alternative to Kjeldahl digestion for routine determination of nitrogen and phosphorus in surface- and ground-water samples in a large-scale and geographically diverse study conducted by U.S. Geological Survey (USGS) between October 1, 2001, and September 30, 2002. Data for this study were obtained from about 2,100 surface- and ground-water samples that were analyzed for Kjeldahl nitrogen and Kjeldahl phosphorus in the course of routine operations at the USGS National Water Quality Laboratory (NWQL). These samples were analyzed independently for total nitrogen and total phosphorus using an alkaline persulfate digestion method developed by the NWQL Methods Research and Development Program. About half of these samples were collected during nominally high-flow (April-June) conditions and the other half were collected during nominally low-flow (August-September) conditions. The number of filtered and whole-water samples analyzed from each flow regime was about equal.By operational definition, Kjeldahl nitrogen (ammonium + organic nitrogen) and alkaline persulfate digestion total nitrogen (ammonium + nitrite + nitrate + organic nitrogen) are not equivalent. It was necessary, therefore, to reconcile this operational difference by subtracting nitrate + nitrite concentra-tions from alkaline persulfate dissolved and total nitrogen concentrations prior to graphical and statistical comparisons with dissolved and total Kjeldahl nitrogen concentrations. On the basis of two-population paired t-test statistics, the means of all nitrate-corrected alkaline persulfate nitrogen and Kjeldahl nitrogen concentrations (2,066 paired results) were significantly different from zero at the p = 0.05 level. Statistically, the means of Kjeldahl nitrogen concentrations were greater than those of nitrate-corrected alkaline persulfate nitrogen concentrations. Experimental evidence strongly

  8. Use of natural mordenite to remove chromium (III) and to neutralize pH of alkaline waste waters.

    PubMed

    Córdova-Rodríguez, Valduvina; Rodríguez-Iznaga, Inocente; Acosta-Chávez, Raquel María; Chávez-Rivas, Fernando; Petranovskii, Vitalii; Pestryakov, Alexey

    2016-01-01

    The natural mordenite from Palmarito de Cauto deposit (PZ), Cuba, was studied in this work as an ion exchanger to remove Cr(3+) cations from alkaline aqueous solutions at different pH and chromium concentrations. The mordenite stability under cyclic treatment processes with alkaline solutions and its capacity to decrease the pH of the solutions was also analyzed. It was shown that PZ removes Cr(3+) ions from alkaline solutions, and it happens independently of the starting chromium concentration and the pH of the exchange solution used. This material has an important neutralizing effect on alkaline solutions, expressed in a significant pH decrease from the early stages of the treatments. For solutions with initial pH equal to 11, it decreases to a value of around seven. The stability of this material is not affected significantly after continuous cyclic treatment with NaOH solution, which shows that mordenite, in particular from Palmarito de Cauto deposit, has high stability in alkaline solutions. The results are important as they suggest that natural zeolites may be of interest in treatments of alkaline industrial waste effluents.

  9. Batch and column adsorption of herbicide fluroxypyr on different types of activated carbons from water with varied degrees of hardness and alkalinity.

    PubMed

    Pastrana-Martínez, L M; López-Ramón, M V; Fontecha-Cámara, M A; Moreno-Castilla, C

    2010-02-01

    There has been little research into the effects of the water hardness and alkalinity of surface waters on the adsorption of herbicides on activated carbons. The aim of this study was to determine the influence of these water characteristics on fluroxypyr adsorption on different activated carbons. At low fluroxypyr surface concentrations, the amount adsorbed from distilled water was related to the surface hydrophobicity. Surface area of carbons covered by fluroxypyr molecules ranged from 60 to 65%. Variations in fluroxypyr solubility with water hardness and alkalinity showed a salting-in effect. Calcium, magnesium and bicarbonate ions were adsorbed to a varied extent on the activated carbons. The presence of fluroxypyr in solution decreased their adsorption due to a competition effect. K(F) from the Freundlich equation linearly increased with water hardness due to salt-screened electrostatic repulsions between charged fluroxypyr molecules. The amount adsorbed from distilled water was largest at high fluroxypyr solution concentrations, because there was no competition between inorganic ions and fluroxypyr molecules. The column breakthrough volume and the amount adsorbed at breakthrough were smaller in tap versus distilled water. Carbon consumption was lower with activated carbon cloth than with the use of granular activated carbon.

  10. Bifunctional enhancement of oxygen reduction reaction activity on Ag catalysts due to water activation on LaMnO3 supports in alkaline media

    PubMed Central

    Park, Shin-Ae; Lee, Eun-Kyung; Song, Hannah; Kim, Yong-Tae

    2015-01-01

    Ag is considered to be one of the best candidates for oxygen reduction reaction electrocatalysts in alkaline media for application in various electrochemical energy devices. In this study, we demonstrate that water activation is a key factor in enhancing the ORR activity in alkaline media, unlike in acid environments. Ag supported on LaMnO3 having a high oxophilicity showed a markedly higher ORR activity than that on carbon with inert surfaces. Through various electrochemical tests, it was revealed that the origin of the enhanced ORR activity of Ag/LaMnO3 is the bifunctional effect mainly due to the water activation at the interface between Ag and LaMnO3. Furthermore, the ligand effect due to the charge transfer from Mn to Ag leads to the enhancement of both oxygen activation on Ag and water activation on Mn sites, and hence, an improvement in the ORR activity of Ag/LaMnO3. On the other hand, the strain effect based on the fine structure variation in the lattice was negligible. We therefore suggest that the employment of a co-catalyst or support with highly oxophilic nature and the maximization of the interface between catalyst and support should be considered in the design of electrocatalysts for the ORR in alkaline media. PMID:26310526

  11. Validity of Monod kinetics at different sludge ages--peptone biodegradation under aerobic conditions.

    PubMed

    Orhon, Derin; Cokgor, Emine Ubay; Insel, Guclu; Karahan, Ozlem; Katipoglu, Tugce

    2009-12-01

    The study presented an evaluation of the effect of culture history (sludge age) on the growth kinetics of a mixed culture grown under aerobic conditions. It involved an experimental setup where a lab-scale sequencing batch reactor was operated at steady-state at two different sludge ages (theta(X)) of 2 and 10 days. The system sustained a mixed culture fed with a synthetic substrate mainly consisting of peptone. The initial concentration of substrate COD was selected around 500 mg COD/L. Polyhydroxyalkanoate (PHA) storage occurred to a limited extent, around 30 mg COD/L for theta(X)=10 days and 15 mg COD/L for theta(X)=2 days. Evaluation of the experimental data based on calibration of two different models provided consistent and reliable evidence for a variable Monod kinetics where the maximum specific growth rate, was assessed as 6.1/day for theta(X)=2 days and 4.1/day for theta(X)=10 days. A similar variability was also applicable for the hydrolysis and storage kinetics. The rate of storage was significantly lower than the levels reported in the literature, exhibiting the ability of the microorganisms to regulate their metabolic mechanisms for adjusting the rate of microbial growth and storage competing for the same substrate. This adjustment evidently resulted in case-specific, variable kinetics both for microbial growth and substrate storage.

  12. The impact of sedimentary alkalinity release on the water column CO2 system in the North Sea

    NASA Astrophysics Data System (ADS)

    Brenner, H.; Braeckman, U.; Le Guitton, M.; Meysman, F. J. R.

    2015-08-01

    Recently, it has been proposed that alkalinity release from sediments can play an important role in the carbonate dynamics on continental shelves, lowering the pCO2 of seawater and hence increasing the CO2 uptake from the atmosphere. To test this hypothesis, sedimentary alkalinity generation was quantified within permeable and muddy sediments across the North Sea during two cruises in September 2011 (basin-wide) and June 2012 (Dutch coastal zone). Benthic fluxes of alkalinity (AT) and dissolved inorganic carbon (DIC) were determined using shipboard closed sediment incubations. These results show that sediments can be an important source for alkalinity, particularly in the shallow southern North Sea, where high AT and DIC fluxes were recorded in near shore sediments of the Belgian, Dutch and German coastal zone. In contrast, fluxes of AT and DIC are substantially lower in the deeper, seasonally stratified, northern part of the North Sea. Overall, our results show that sedimentary alkalinity generation should be considered an important factor in the CO2 dynamics of shallow coastal systems.

  13. Rhesus glycoprotein and urea transporter genes in rainbow trout embryos are upregulated in response to alkaline water (pH 9.7) but not elevated water ammonia.

    PubMed

    Sashaw, Jessica; Nawata, Michele; Thompson, Sarah; Wood, Chris M; Wright, Patricia A

    2010-03-01

    Recent studies have shown that genes for the putative ammonia transporter, Rhesus glycoproteins (Rh) and the facilitated urea transporter (UT) are expressed before hatching in rainbow trout (Oncorhychus mykiss Walbaum) embryos. We tested the hypothesis that Rh and UT gene expressions are regulated in response to environmental conditions that inhibit ammonia excretion during early life stages. Eyed-up embryos (22 days post-fertilization (dpf)) were exposed to control (pH 8.3), high ammonia (1.70 mmol l(-1) NH4HCO3) and high pH (pH 9.7) conditions for 48h. With exposure to high water ammonia, ammonia excretion rates were reversed, tissue ammonia concentration was elevated by 9-fold, but there were no significant changes in mRNA expression relative to control embryos. In contrast, exposure to high water pH had a smaller impact on ammonia excretion rates and tissue ammonia concentrations, whereas mRNA levels for the Rhesus glycoprotein Rhcg2 and urea transporter (UT) were elevated by 3.5- and 5.6-fold, respectively. As well, mRNAs of the genes for H+ATPase and Na+/H+ exchanger (NHE2), associated with NH3 excretion, were also upregulated by 7.2- and 13-fold, respectively, in embryos exposed to alkaline water relative to controls. These results indicate that the Rhcg2, UT and associated transport genes are regulated in rainbow trout embryos, but in contrast to adults, there is no effect of high external ammonia at this stage of development.

  14. Synthesis and characterization of NiFe2O4 electrocatalyst for the hydrogen evolution reaction in alkaline water electrolysis using different polymer binders

    NASA Astrophysics Data System (ADS)

    Chanda, Debabrata; Hnát, Jaromír; Paidar, Martin; Schauer, Jan; Bouzek, Karel

    2015-07-01

    NiFe2O4 electrocatalyst for the hydrogen evolution reaction (HER) has been synthesized using the co-precipitation method of the respective metal ions from water solution. After calcination of the precipitate, the resulting electrocatalyst was characterized by a broad range of techniques to obtain information on its crystallographic structure, specific surface area, morphology and chemical composition. The electrocatalytic activity towards HER in alkaline water electrolysis was investigated by means of linear sweep voltammetry. The catalyst showed promising electrocatalytic properties. Subsequently three types of binders were used to prepare a cathode catalytic layer based on a catalyst synthesized on top of a nickel foam support, namely an anion-selective quaternized poly(phenylene oxide) (qPPO) ionomer, an electroneutral polymer polytetrafluoroethylene and cation-selective Nafion®. The resulting membrane-electrode assemblies (MEAs), based on an anion-selective membrane, were tested in an alkaline water electrolyzer. In a single-cell test the MEA with a qPPO ionomer exhibited higher HER activity compared to the remaining binders tested. The current density obtained using a MEA containing qPPO binder attained a value of 125 mA cm-2 at a cell voltage of 1.85 V. The stability of the MEA containing qPPO binder was examined by continuous operation for 143 h, followed by 55 h intermittent electrolysis.

  15. Microwave-Initiated Facile Formation of Ni3Se4 Nanoassemblies for Enhanced and Stable Water Splitting in Neutral and Alkaline Media.

    PubMed

    Anantharaj, Sengeni; Kennedy, Jeevarathinam; Kundu, Subrata

    2017-02-28

    Molecular hydrogen (H2) generation through water splitting with minimum energy loss has become practically possible due to the recent evolution of high-performance electrocatalysts. In this study, we fabricated, evaluated, and presented such a high-performance catalyst which is the Ni3Se4 nanoassemblies that can efficiently catalyze water splitting in neutral and alkaline media. A hierarchical nanoassembly of Ni3Se4 was fabricated by functionalizing the surface-cleaned Ni foam using NaHSe solution as the Se source with the assistance of microwave irradiation (300 W) for 3 min followed by 5 h of aging at room temperature (RT). The fabricated Ni3Se4 nanoassemblies were subjected to catalyze water electrolysis in neutral and alkaline media. For a defined current density of 50 mA cm(-2), the Ni3Se4 nanoassemblies required very low overpotentials for the oxygen evolution reaction (OER), viz., 232, 244, and 321 mV at pH 14.5, 14.0, and 13.0 respectively. The associated lower Tafel slope values (33, 30, and 40 mV dec(-1)) indicate the faster OER kinetics on Ni3Se4 surfaces in alkaline media. Similarly, in the hydrogen evolution reaction (HER), for a defined current density of 50 mA cm(-2), the Ni3Se4 nanoassemblies required low overpotentials of 211, 206, and 220 mV at pH 14.5, 14.0, and 13.0 respectively. The Tafel slopes for HER at pH 14.5, 14.0, and 13.0 are 165, 156, and 128 mV dec(-1), respectively. A comparative study on both OER and HER was carried out with the state-of-the-art RuO2 and Pt under identical experimental conditions, the results of which revealed that our Ni3Se4 is a far better high-performance catalyst for water splitting. Besides, the efficiency of Ni3Se4 nanoassemblies in catalyzing water splitting in neutral solution was carried out, and the results are better than many previous reports. With these amazing advantages in fabrication method and in catalyzing water splitting at various pH, the Ni3Se4 nanoassemblies can be an efficient, cheaper

  16. Effects of co-application of biosolids and water treatment residuals on corn growth and bioavailable phosphorus and aluminum in alkaline soils in egypt.

    PubMed

    Mahdy, A M; Elkhatib, E A; Fathi, N O; Lin, Z-Q

    2009-01-01

    The co-application of biosolids and water treatment residuals (WTRs) has been previously trialed to reduce excessive bioavailable P in the soil treated with biosolids. However, uncertainty still exists regarding the environmental consequences of the co-application of biosolids and WTRs, especially in alkaline soils in Egypt or the Middle East region. A greenhouse pot study was conducted with Egyptian alkaline soils to (i) quantify the effects of co-application of biosolids and drinking WTRs on biomass production of corn (Zea mays L. cultivar single hybrid 10), (ii) determine the co-application effects on Olsen-P and KCl-extractable Al in relation to their accumulation in plant tissues, and (iii) optimize the co-application ratio of biosolids to WTRs for the best yield and effective reduction of soil bioavailable P. The results show that, among the studied soils treated with 1% biosolids along with various rates of WTRs, the corn yield increased significantly (P < 0.01) with increasing WTR application rate from 0 to 3% (w/w), but decreased at 4% application rate. The corn yield also significantly correlated with soil water holding capacity that increased with the addition of WTRs. Phosphorus uptake by plants significantly (P < 0.01) increased when the biosolid application rate was increased from 1 to 3% in the three studied soils that were treated with 1, 2, or 3% WTRs. The application of 4% WTRs in the biosolid-amended soils resulted in a significant reduction in soil Olsen-P values, but without having observable phytotoxicity of metals (such as Al) to corn during the growth period. The effective co-application ratio of biosolids to WTRs, for increasing corn yield and minimizing the potential for bioavailable P in runoff, was approximately 1:1 at the application rate of 3% biosolids and 4% WTRs in the alkaline soils.

  17. High-resolution Imaging of pH in Alkaline Sediments and Water Based on a New Rapid Response Fluorescent Planar Optode

    NASA Astrophysics Data System (ADS)

    Han, Chao; Yao, Lei; Xu, Di; Xie, Xianchuan; Zhang, Chaosheng

    2016-05-01

    A new dual-lumophore optical sensor combined with a robust RGB referencing method was developed for two-dimensional (2D) pH imaging in alkaline sediments and water. The pH sensor film consisted of a proton-permeable polymer (PVC) in which two dyes with different pH sensitivities and emission colors: (1) chloro phenyl imino propenyl aniline (CPIPA) and (2) the coumarin dye Macrolex® fluorescence yellow 10 GN (MFY-10 GN) were entrapped. Calibration experiments revealed the typical sigmoid function and temperature dependencies. This sensor featured high sensitivity and fast response over the alkaline working ranges from pH 7.5 to pH 10.5. Cross-sensitivity towards ionic strength (IS) was found to be negligible for freshwater when IS <0.1 M. The sensor had a spatial resolution of approximately 22 μm and aresponse time of <120 s when going from pH 7.0 to 9.0. The feasibility of the sensor was demonstrated using the pH microelectrode. An example of pH image obtained in the natrual freshwater sediment and water associated with the photosynthesis of Vallisneria spiral species was also presented, suggesting that the sensor held great promise for the field applications.

  18. High-resolution Imaging of pH in Alkaline Sediments and Water Based on a New Rapid Response Fluorescent Planar Optode

    PubMed Central

    Han, Chao; Yao, Lei; Xu, Di; Xie, Xianchuan; Zhang, Chaosheng

    2016-01-01

    A new dual-lumophore optical sensor combined with a robust RGB referencing method was developed for two-dimensional (2D) pH imaging in alkaline sediments and water. The pH sensor film consisted of a proton-permeable polymer (PVC) in which two dyes with different pH sensitivities and emission colors: (1) chloro phenyl imino propenyl aniline (CPIPA) and (2) the coumarin dye Macrolex® fluorescence yellow 10 GN (MFY-10 GN) were entrapped. Calibration experiments revealed the typical sigmoid function and temperature dependencies. This sensor featured high sensitivity and fast response over the alkaline working ranges from pH 7.5 to pH 10.5. Cross-sensitivity towards ionic strength (IS) was found to be negligible for freshwater when IS <0.1 M. The sensor had a spatial resolution of approximately 22 μm and aresponse time of <120 s when going from pH 7.0 to 9.0. The feasibility of the sensor was demonstrated using the pH microelectrode. An example of pH image obtained in the natrual freshwater sediment and water associated with the photosynthesis of Vallisneria spiral species was also presented, suggesting that the sensor held great promise for the field applications. PMID:27199163

  19. Statistical optimization of alkaline protease production from Penicillium citrinum YL-1 under solid-state fermentation.

    PubMed

    Xiao, Yun-Zhu; Wu, Duan-Kai; Zhao, Si-Yang; Lin, Wei-Min; Gao, Xiang-Yang

    2015-01-01

    Proteases from halotolerant and halophilic microorganisms were found in traditional Chinese fish sauce. In this study, 30 fungi were isolated from fermented fish sauce in five growth media based on their morphology. However, only one strain, YL-1, which was identified as Penicillium citrinum by internal transcribed spacer (ITS) sequence analysis, can produce alkaline protease. This study is the first to report that a protease-producing fungus strain was isolated and identified in traditional Chinese fish sauce. Furthermore, the culture conditions of alkaline protease production by P. citrinum YL-1 in solid-state fermentation were optimized by response surface methodology. First, three variables including peptone, initial pH, and moisture content were selected by Plackett-Burman design as the significant variables for alkaline protease production. The Box-Behnken design was then adopted to further investigate the interaction effects between the three variables on alkaline protease production and determine the optimal values of the variables. The maximal production (94.30 U/mL) of alkaline protease by P. citrinum YL-1 took place under the optimal conditions of peptone, initial pH, and moisture content (v/w) of 35.5 g/L, 7.73, and 136%, respectively.

  20. Environmentally Asisted Cracking Behavior of Nickel Alloys in Simulated Acidic and Alkaline Ground Waters Using U-bend Specimens

    SciTech Connect

    Fix, D V; Estill, J C; Hust, G A; Wong, L L; Rebak, R B

    2003-10-17

    The model for the degradation of the containers for nuclear waste includes three modes of corrosion, namely general corrosion, localized corrosion and environmentally assisted cracking (EAC). The objective of the current research was to quantify the susceptibility of five nickel alloys to EAC in several environmental conditions with varying solution composition, temperature and electrochemical potential. These alloys included: Alloy 22 (N06022), Alloy C-4 (N06455), Alloy 625 (N06625), Alloy G-3 (N06985) and Alloy 825 (N08825). The susceptibility to EAC was evaluated using constant deformation (deflection) U-bend specimens in both the non-welded (wrought) and welded conditions. Results show that after more than five years exposure in the vapor and liquid phases of alkaline (pH {approx} 10) and acidic (pH {approx} 3) multi-ionic environments at 60 C and 90 C, none of the tested alloys suffered environmentally assisted cracking.

  1. Insights into the effect of dilute acid, hot water and alkaline pretreatment on cellulose accessible surface area and overall porosity of Populus

    SciTech Connect

    Meng, Xianzhi; Wells, Tyrone; Sun, Qining; Huang, Fang; Ragauskas, Arthur J.

    2015-06-19

    Pretreatment is known to render biomass more reactive to cellulase by altering the chemical compositions as well as physical structures of biomass. Simons stain technique along with mercury porosimetry were applied on the acid, neutral, and alkaline pretreated materials to measure the accessible surface area of cellulose and pore size distribution of Populus. Results indicated that acid pretreatment is much more effective than water and alkaline pretreatment in terms of cellulose accessibility increase. Further investigation suggests that lignin does not dictate cellulose accessibility to the extent that hemicellulose does, but it does restrict xylan accessibility which in turn controls the access of cellulase to cellulose. The most interesting finding is that severe acid pretreatment significantly decreases the average pore size, i.e., 90% average size decrease could be observed after 60 min dilute acid pretreatment at 160 °C; moreover, the nano-pore space formed between coated microfibrils is increased after pretreatment, especially for the acid pretreatment, suggesting this particular type of biomass porosity is probably the most fundamental barrier to effective enzymatic hydrolysis.

  2. Insights into the effect of dilute acid, hot water and alkaline pretreatment on cellulose accessible surface area and overall porosity of Populus

    DOE PAGES

    Meng, Xianzhi; Wells, Tyrone; Sun, Qining; ...

    2015-06-19

    Pretreatment is known to render biomass more reactive to cellulase by altering the chemical compositions as well as physical structures of biomass. Simons stain technique along with mercury porosimetry were applied on the acid, neutral, and alkaline pretreated materials to measure the accessible surface area of cellulose and pore size distribution of Populus. Results indicated that acid pretreatment is much more effective than water and alkaline pretreatment in terms of cellulose accessibility increase. Further investigation suggests that lignin does not dictate cellulose accessibility to the extent that hemicellulose does, but it does restrict xylan accessibility which in turn controls themore » access of cellulase to cellulose. The most interesting finding is that severe acid pretreatment significantly decreases the average pore size, i.e., 90% average size decrease could be observed after 60 min dilute acid pretreatment at 160 °C; moreover, the nano-pore space formed between coated microfibrils is increased after pretreatment, especially for the acid pretreatment, suggesting this particular type of biomass porosity is probably the most fundamental barrier to effective enzymatic hydrolysis.« less

  3. "Isolation, identification, characterization and polymetallic concentrate leaching studies of tryptic soy- and peptone-resistant thermotolerant Acidithiobacillus ferrooxidans SRDSM2".

    PubMed

    Patel, Mitesh J; Tipre, Devayani R; Dave, Shailesh R

    2011-01-01

    Acidithiobacillus ferrooxidans strain SRDSM2 was isolated from silica containing soil sample collected at a Rajpardi lignite mine. The strain responded to the addition of 0.5 g/L peptone and 1.0 g/L tryptone soya broth in the ferrous sulphate tryptone soya broth (ITSB) medium with 35.3% and 29.6% increase in iron oxidation rate (IOR), but decrease in the IOR at higher peptone or tryptone soya broth levels. The presence of 4 mM of zinc as zinc sulphate in the medium increased the IOR by 24.4%. Forty percent of the inoculated cells survived even after exposure at 80 °C for 120 min and showed 30% ferrous iron oxidation. The Vmax and Ks for iron oxidation by the isolate were 344.82 mg/L/h and 32.25 g/L respectively. The isolate was able to oxidized ferrous iron even in presence of 4.06 M ionic strength of medium and leached>85% copper and zinc from the polymetallic concentrate. Thus, this isolate can be used for bioextraction of metals from polymetallic concentrate.

  4. The use of aluminum oxychlorides to coagulate water having high content of organic impurities and low alkalinity

    NASA Astrophysics Data System (ADS)

    Evsyutin, A. V.; Boglovskii, A. V.

    2007-07-01

    Results from laboratory investigations and industrial tests of the coagulation of source water at the Pskov district power station are presented. It is shown that the source water may not be alkalified if it is treated with aluminum oxychlorides. As a result, the clarified water becomes less corrosive and a lower salt load is placed on water treatment plants as compared with the case when aluminum sulfate is used for coagulation.

  5. Low pressure ion chromatography with a low cost paired emitter-detector diode based detector for the determination of alkaline earth metals in water samples.

    PubMed

    Barron, Leon; Nesterenko, Pavel N; Diamond, Dermot; O'Toole, Martina; Lau, King Tong; Paull, Brett

    2006-09-01

    The use of a low pressure ion chromatograph based upon short (25 mm x 4.6 mm) surfactant coated monolithic columns and a low cost paired emitter-detector diode (PEDD) based detector, for the determination of alkaline earth metals in aqueous matrices is presented. The system was applied to the separation of magnesium, calcium, strontium and barium in less than 7min using a 0.15M KCl mobile phase at pH 3, with post-column reaction detection at 570 nm using o-cresolphthalein complexone. A comparison of the performance of the PEDD detector with a standard laboratory absorbance detector is shown, with limits of detection for magnesium and calcium using the low cost PEDD detector equal to 0.16 and 0.23 mg L(-1), respectively. Finally, the developed system was used for the determination of calcium and magnesium in a commercial spring water sample.

  6. Water oxidation with mononuclear ruthenium(II) polypyridine complexes involving a direct Ru(IV)═O pathway in neutral and alkaline media.

    PubMed

    Badiei, Yosra M; Polyansky, Dmitry E; Muckerman, James T; Szalda, David J; Haberdar, Rubabe; Zong, Ruifa; Thummel, Randolph P; Fujita, Etsuko

    2013-08-05

    The catalytic water oxidation mechanism proposed for many single-site ruthenium complexes proceeds via the nucleophilic attack of a water molecule on the Ru(V)═O species. In contrast, Ru(II) complexes containing 4-t-butyl-2,6-di-1',8'-(naphthyrid-2'-yl)-pyridine (and its bisbenzo-derivative), an equatorial water, and two axial 4-picolines follow the thermodynamically more favorable "direct pathway" via [Ru(IV)═O](2+), which avoids the higher oxidation state [Ru(V)═O](3+) in neutral and basic media. Our experimental and theoretical results that focus on the pH-dependent onset catalytic potentials indicative of a PCET driven low-energy pathway for the formation of products with an O-O bond (such as [Ru(III)-OOH](2+) and [Ru(IV)-OO](2+)) at an applied potential below the Ru(V)═O/Ru(IV)═O couple clearly support such a mechanism. However, in the cases of [Ru(tpy)(bpy)(OH2)](2+) and [Ru(tpy)(bpm)(OH2)](2+), the formation of the Ru(V)═O species appears to be required before O-O bond formation. The complexes under discussion provide a unique functional model for water oxidation that proceeds by four consecutive PCET steps in neutral and alkaline media.

  7. Growth of Campylobacter incubated aerobically in fumarate-pyruvate media or media supplemented with dairy, meat, or soy extracts and peptones.

    PubMed

    Hinton, Arthur

    2016-09-01

    The ability of Campylobacter to grow aerobically in media supplemented with fumarate-pyruvate or with dairy, meat, or soy extracts or peptones was examined. Optical densities (OD) of Campylobacter cultured in basal media, media supplemented with fumarate-pyruvate or with 1.0, 2.5, 5.0, or 7.5% beef extract was measured. Growth was also compared in media supplemented with other extracts or peptones. Finally, cfu/mL of Campylobacter recovered from basal media or media supplemented with fumarate-pyruvate, casamino acids, beef extract, soytone, or beef extract and soytone was determined. Results indicated that OD of cultures grown in media supplemented with fumarate-pyruvate or with 5.0 or 7.5% beef extract were higher than OD of isolates grown in basal media or media supplemented with lower concentrations of beef extract. Highest OD were produced by isolates grown in media supplemented with beef extract, peptone from meat, polypeptone, proteose peptone, or soytone. Also, more cfu/mL were recovered from media with fumarate-pyruvate, beef extract, soytone, or beef extract-soytone than from basal media or media with casamino acids. Findings indicate that media supplemented with organic acids, vitamins, and minerals and media supplemented with extracts or peptones containing these metabolites can support aerobic growth of Campylobacter.

  8. Strategies for regulation of hemolymph pH in acidic and alkaline water by the larval mosquito Aedes aegypti (L.) (Diptera; Culicidae).

    PubMed

    Clark, Thomas M; Vieira, Marcus A L; Huegel, Kara L; Flury, Dawn; Carper, Melissa

    2007-12-01

    The responses of larval Aedes aegypti to media of pH 4, 7 and 11 provide evidence for pH regulatory strategies. Drinking rates in pH 4 media were elevated 3- to 5-fold above those observed in pH 7 or 11. Total body water was elevated during acute exposure to acidic media. During chronic exposure, total body water was decreased and Malpighian tubule mitochondrial luminosity, quantified using Mitotracker Green FM, increased. Malpighian tubule secretion rates and energy demands thus appear to increase dramatically during acid exposure. In alkaline media, drinking rates were quite low. Larvae in pH 11 media excreted net acid (0.12 nequiv H(+) g(-1) h(-1)) and the pH indicators azolitmin and bromothymol blue revealed that the rectal lumen is acidic in vivo at all ambient pH values. The anal papillae (AP) were found to be highly permeant to acid-base equivalents. Ambient pH influenced the length, and the mass-specific length, of the AP in the presence of NaCl (59.9 mmol l(-1)). In contrast, the length and mass-specific length of AP were not influenced by ambient pH in low NaCl conditions. Mitochondrial luminosity was reduced in AP of larvae reared in acidic media, and was not elevated in alkaline media, relative to that of larvae reared in neutral media. These data suggest that the AP may compromise acid-base balance in acidic media, and may also be an important site of trade-offs between H(+) homeostasis and NaCl uptake in dilute, acidic media.

  9. Unimolecular and hydrolysis channels for the detachment of water from microsolvated alkaline earth dication (Mg2+, Ca2+, Sr2+, Ba2+) clusters

    SciTech Connect

    Miliordos, Evangelos; Xantheas, Sotiris S.

    2014-02-07

    We examine theoretically the three channels that are associated with the detachment of a single water molecule from the aqueous clusters of the alkaline earth dications, [M(H2O)n]2+, M = Mg, Ca, Sr, Ba, n ≤ 6. These are the unimolecular water loss (M2+(H2O)n-1 + H2O) and the two hydrolysis channels resulting to the loss of hydronium ([MOH(H2O)n-2]+ + H3O+) and Zundel ([MOH(H2O)n-3]+ + H3O+(H2O)) cations. The Potential Energy Curves (PECs) corresponding to those three channels were constructed at the Møller-Plesset second order perturbation (MP2) level of theory with basis sets of double- and triple-ζ quality. We furthermore investigated the water and hydronium loss channels from the mono-hydroxide water clusters with up to four water molecules, [MOH(H2O)n]+, 1 ≤ n ≤ 4. Our results indicate the preference of the hydronium loss and possibly the Zundel cation loss channels for the smallest size clusters, whereas the unimolecular water loss channel is preferred for the larger ones as well as the mono-hydroxide clusters. Although the charge separation (hydronium and Zundel cation loss) channels produce more stable products when compared to the ones for the unimolecular water loss, they also require the surmounting of high energy barriers, a fact that makes the experimental observation of fragments related to these hydrolysis channels difficult.

  10. In situ generation of steam and alkaline surfactant for enhanced oil recovery using an exothermic water reactant (EWR)

    DOEpatents

    Robertson, Eric P

    2011-05-24

    A method for oil recovery whereby an exothermic water reactant (EWR) encapsulated in a water soluble coating is placed in water and pumped into one or more oil wells in contact with an oil bearing formation. After the water carries the EWR to the bottom of the injection well, the water soluble coating dissolves and the EWR reacts with the water to produce heat, an alkali solution, and hydrogen. The heat from the EWR reaction generates steam, which is forced into the oil bearing formation where it condenses and transfers heat to the oil, elevating its temperature and decreasing the viscosity of the oil. The aqueous alkali solution mixes with the oil in the oil bearing formation and forms a surfactant that reduces the interfacial tension between the oil and water. The hydrogen may be used to react with the oil at these elevated temperatures to form lighter molecules, thus upgrading to a certain extent the oil in situ. As a result, the oil can flow more efficiently and easily through the oil bearing formation towards and into one or more production wells.

  11. Hypersensitivity of Ranunculus asiaticus to salinity and alkaline pH in irrigation water in sand cultures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ranunculus, grown as a field crop in southern and central coastal California, is highly valued in the cut flower and tuberous root markets. Concerns regarding the sustainability of Ranunculus cultivation have arisen when the plantations are irrigated with municipal-treated waters. Although cut flo...

  12. Stochastic modeling of filtrate alkalinity in water filtration devices: Transport through micro/nano porous clay based ceramic materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Clay and plant materials such as wood are the raw materials used in manufacture of ceramic water filtration devices around the world. A step by step manufacturing procedure which includes initial mixing, molding and sintering is used. The manufactured ceramic filters have numerous pores which help i...

  13. Straddling the tholeiitic/calc-alkaline transition: the effects of modest amounts of water on magmatic differentiation at Newberry Volcano, Oregon

    NASA Astrophysics Data System (ADS)

    Mandler, Ben E.; Donnelly-Nolan, Julie M.; Grove, Timothy L.

    2014-10-01

    Melting experiments have been performed at 1 bar (anhydrous) and 1- and 2-kbar H2O-saturated conditions to study the effect of water on the differentiation of a basaltic andesite. The starting material was a mafic pumice from the compositionally zoned tuff deposited during the ~75 ka caldera-forming eruption of Newberry Volcano, a rear-arc volcanic center in the central Oregon Cascades. Pumices in the tuff of Newberry caldera (TNC) span a continuous silica range from 53 to 74 wt% and feature an unusually high-Na2O content of 6.5 wt% at 67 wt% SiO2. This wide range of magmatic compositions erupted in a single event makes the TNC an excellent natural laboratory in which to study the conditions of magmatic differentiation. Our experimental results and mineral-melt hygrometers/thermometers yield similar estimates of pre-eruptive H2O contents and temperatures of the TNC liquids. The most primitive (mafic) basaltic andesites record a pre-eruptive H2O content of 1.5 wt% and a liquidus temperature of 1,060-1,070 °C at upper crustal pressure. This modest H2O content produces a distinctive fractionation trend that is much more enriched in Na, Fe, and Ti than the calc-alkaline trend typical of wetter arc magmas, but slightly less enriched in Fe and Ti than the tholeiitic trend of dry magmas. Modest H2O contents might be expected at Newberry Volcano given its location in the Cascade rear arc, and the same fractionation trend is also observed in the rim andesites of the rear-arc Medicine Lake volcano in the southern Cascades. However, the Na-Fe-Ti enrichment characteristic of modest H2O (1-2 wt%) is also observed to the west of Newberry in magmas erupted from the arc axis, such as the Shevlin Park Tuff and several lava flows from the Three Sisters. This shows that modest-H2O magmas are being generated directly beneath the arc axis as well as in the rear arc. Because liquid lines of descent are particularly sensitive to water content in the range of 0-3 wt% H2O, they provide a

  14. An Alkaline Protease from Bacillus pumilus MP 27: Functional Analysis of Its Binding Model toward Its Applications As Detergent Additive

    PubMed Central

    Baweja, Mehak; Tiwari, Rameshwar; Singh, Puneet K.; Nain, Lata; Shukla, Pratyoosh

    2016-01-01

    A proteolytic strain of Bacillus pumilus MP 27 was isolated from water samples of Southern ocean produced alkaline protease. Since protease production need expensive ingredients, an economically viable process was developed by using low cost carbon source, wheat straw, supplemented with peptone. This protease was active within temperature ranges 10–70°C at pH 9. This process was optimized by response surface methodology using a Box Bekhman design by Design Expert 7.0 software that increased the protease activity to 776.5 U/ml. Moreover, the enzyme was extremely stable at a broad range of temperature and pH retaining 69% of its activity at 50°C and 70% at pH 11. The enzyme exhibited excellent compatibility with surfactants and commercial detergents, showing 87% stability with triton X-100 and 100% stability with Tide commercial detergent. The results of the wash performance analysis demonstrated considerably good de-staining at 50 and 4°C with low supplementation (109 U/ml). Molecular modeling of the protease revealed the presence of serine proteases, subtilase family and serine active site and further docking supported the association of catalytic site with the various substrates. Certainly, such protease can be considered as a good detergent additive in detergent industry with a possibility to remove the stains effectively even in a cold wash. PMID:27536284

  15. Toxicity of alkalinity to Hyalella azteca

    USGS Publications Warehouse

    Lasier, P.J.; Winger, P.V.; Reinert, R.E.

    1997-01-01

    Toxicity testing and chemical analyses of sediment pore water have been suggested for use in sediment quality assessments and sediment toxicity identification evaluations. However, caution should be exercised in interpreting pore-water chemistry and toxicity due to inherent chemical characteristics and confounding relationships. High concentrations of alkalinity, which are typical of sediment pore waters from many regions, have been shown to be toxic to test animals. A series of tests were conducted to assess the significance of elevated alkalinity concentrations to Hyalella azteca, an amphipod commonly used for sediment and pore-water toxicity testing. Toxicity tests with 14-d old and 7-d old animals were conducted in serial dilutions of sodium bicarbonate (NaHCO3) solutions producing alkalinities ranging between 250 to 2000 mg/L as CaCO3. A sodium chloride (NaCl) toxicity test was also conducted to verify that toxicity was due to bicarbonate and not sodium. Alkalinity was toxic at concentrations frequently encountered in sediment pore water. There was also a significant difference in the toxicity of alkalinity between 14-d old and 7-d old animals. The average 96-h LC50 for alkalinity was 1212 mg/L (as CaCO3) for 14-d old animals and 662 mg/L for the younger animals. Sodium was not toxic at levels present in the NaHCO3 toxicity tests. Alkalinity should be routinely measured in pore-water toxicity tests, and interpretation of toxicity should consider alkalinity concentration and test-organism tolerance.

  16. [Aeromonas spp. and Plesiomonas shigelloides in bivalves, mud, and water from the Gulf of Nicoya, Costa Rica].

    PubMed

    Rodríguez, E; Antillón, F

    1989-06-01

    Bivalves, mud, and surface water were collected at three different sites of the Gulf of Nicoya, Costa Rica, in search of Aeromonas spp. and Plesiomonas shigelloides. For their isolation, these bacteria were enriched in alkaline peptone water and streaked on MacConkey agar and on brilliant green bile inositol agar. This was followed by the biochemical tests necessary for their identification. Thirty-five strains of A. hydrophila, 58 of A. caviae, 43 of A. sobria, and 7 of P. shigelloides were isolated. None of these predominated nor was there any indication of a seasonal distribution along the 15 month's duration of the study. Seven strains of A. hydrophila and two of A. sobria showed the biochemical characteristics associated with toxin production (positive Voges-Proskauer and lysine decarboxylase tests). These species are widely distributed in the gulf and there is risk of contracting an infection while bathing or when eating raw bivalves from this area.

  17. Advanced water alkaline electrolysis - A two years running of a test plant: 120 C - 160 C, 20 bars /about 300 p.s.i./

    NASA Astrophysics Data System (ADS)

    Bailleux, C.

    Results acquired in the two-year operation of an advanced pressurized forced-flow alkaline water electrolysis test plant are reported. The test loop consists of eight monopolar cells, circulator, filter units and heat exchangers designed to operate with a 40 wt percent KOH electrolyte at a temperature between 120 and 160 C, a pressure of 20 bars, a current density of 10 kA/sq M and input electric power of 1.75 W. Each cell is made up of two shells of 290 mm external diameter and thickness 40 mm on either side of an FEP-coated diaphragm with a working area of 120 x 120 mm. During the two years of operation, the duty factor for temperature operation has increased from 44 percent to more than 80 percent and that for electrolysis operation has increased from 27 percent to 60 percent, with continuous steady state operation for as long as 35 days. Tests have confirmed the stability of a chrysotile asbestos diaphragm when the electrolyte is doped with silica ions, and revealed deteriorations in materials stability due to gasket creep and metal corrosion. The behavior of the nickel electrodes was observed to be influenced by operating temperatures, cathodic deposits, electrode structure and thermal treatment. In spite of the careful design of the gravity separating tanks, purity of the produced O2 was found unsatifactory, although no trouble arose on the hydrogen side. Results of the operation of the test loop have been scaled up in order to predict the performance of a large-scale pilot plant.

  18. Anodes for alkaline electrolysis

    DOEpatents

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  19. Interpretation of pH, acidity, and alkalinity in fisheries and aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measurements of pH, acidity, and alkalinity are commonly used to describe water quality. The three variables are interrelated and are sometimes confused. The pH of water is an intensity factor, while the acidity and alkalinity of waters are capacity factors. More precisely, acidity and alkalinity ar...

  20. [Prevalence of Aeromonas spp. in surface water].

    PubMed

    Hernández, P; Rodríguez de García, R

    1997-03-01

    Some Aeromonas strains are well recognized enteropathogens according to microbiological, clinical, immunological and epidemiological evidence. The main source of infection seems to be untreated water, these microorganisms can be found in virtually all aquatic environments. Additionally, some Aeromonas, which include enterotoxigenic strains, are capable of rapid growth at 5 degrees C and even of producing toxins. Vegetable products irrigated with contaminated water may reach critical Aeromonas levels after being kept under refrigeration, this could represent a public health risk when they are consumed as uncooked salads. This study was pursued to evaluate such risk. Surface water samples were streaked on starch ampicillin and inositol-brilliant green-bile salts agar dishes. In addition, 100 ml of each sample were filtered through a 0.45 micron Millipore membrane filter. The filters were incubated on alkaline peptone water as enrichment media during 24 h at 35 degrees C. Enrichment broth was then streaked on the selective agars above mentioned. Isolates from both tests were identified using the API 20 E System. The prevalence of Aeromonas strains in the analyzed samples was 17.8%. A higher isolation rate was observed after the enrichment technique. Starch ampicillin agar showed a higher recuperation rate. A Veronii biotype sobria (formerly A. sobria) was isolated with higher frequency. Since this species has been associated with the greatest virulence, the use of contaminated water to irrigate vegetable products that are to be kept under refrigeration and consumed without ulterior cooking may represent a risk to the public health.

  1. Alkaline battery operational methodology

    DOEpatents

    Sholklapper, Tal; Gallaway, Joshua; Steingart, Daniel; Ingale, Nilesh; Nyce, Michael

    2016-08-16

    Methods of using specific operational charge and discharge parameters to extend the life of alkaline batteries are disclosed. The methods can be used with any commercial primary or secondary alkaline battery, as well as with newer alkaline battery designs, including batteries with flowing electrolyte. The methods include cycling batteries within a narrow operating voltage window, with minimum and maximum cut-off voltages that are set based on battery characteristics and environmental conditions. The narrow voltage window decreases available capacity but allows the batteries to be cycled for hundreds or thousands of times.

  2. Effects of Low Level Water-soluble Pentosans, Alkaline-extractable Pentosans, and Xylanase on the Growth and Development of Broiler Chicks.

    PubMed

    Sheng, Q K; Yang, L Q; Zhao, H B; Wang, X L; Wang, K

    2013-09-01

    This study investigated the effects of low levels of water-soluble pentosans (WSP), alkaline-extractable pentosans (AEP), and xylanase on the growth and organ development of broiler chicks. Three hundred and fifty 1-d-old female broiler chicks were randomly allocated into seven experimental groups of five pen replicates, with ten chicks per replicate. The control group consumed a corn-soybean meal-based diet. Six dietary treatment groups consumed the basal diet supplemented with one of the following: WSP at 50 mg/kg (WSP50) or 100 mg/kg (WSP100); AEP at 50 mg/kg (AEP50) or 100 mg/kg (AEP100); or xylanase at 3 mg/kg (Xase3) or 6 mg/kg (Xase6). Data including the body weight, digestive organ weights, gut length, rectal digesta viscosity, and gut microflora and pH were collected on d 5, 10, and 15. When compared to the control group, WSP50 promoted body weight gain and organ growth throughout the study, calculated as 3-d averages (p<0.05). WSP100 increased weight gain and enhanced organ development (proventriculus, gizzard, and gut) on d 10 (p<0.05), but the 3-d averages were not different from the control group except for the weight of gizzard. Both Xase3 and Xase6 increased the 3-d average weight gain and the growth of the gizzard (p<0.05). WSP50 increased the digesta viscosity compared to Xase3 on d 10 and 15 (p<0.05). WSP50, Xase3, and Xase6 increased the concentration of Lactobacillus in the rectum when compared to the control group (p<0.05), but only Xase3 lowered the digesta pH in the ileum and cecum on d 10 and 15. AEP had minimal influence on the growth and organ development of broilers. The results showed that low levels of WSP, AEP, and xylanase had different effects and underlying mechanisms on the growth and organ development of broiler chicks. WSP50 could increase the growth performance of broilers fed a corn-soybean meal-based diet.

  3. Growth of Azotobacter vinelandii UWD in Fish Peptone Medium and Simplified Extraction of Poly-β-Hydroxybutyrate

    PubMed Central

    Page, William J.; Cornish, Anthony

    1993-01-01

    Azotobacter vinelandii UWD was grown in a fermentor with glucose medium with and without 0.1% fish peptone (FP) in batch and fed-batch cultures for the production of the natural bioplastic poly-β-hydroxybutyrate (PHB). Strain UWD formed PHB five times faster than cell protein during growth in glucose and NH4+, but PHB synthesis stopped when NH4+ was depleted and nitrogen fixation started. When FP was added to the same medium, PHB accumulated 16 times faster than cell protein, which in turn was inhibited by 40%, and PHB synthesis was unaffected by NH4+ depletion. Thus, FP appeared to be used as a nitrogen source by these nitrogen-fixing cells, which permitted enhanced PHB synthesis, but it was not a general growth stimulator. The addition of FP to the medium led to the production of large, pleomorphic, osmotically sensitive cells that demonstrated impaired growth and partial lysis, with the leakage of DNA into the culture fluid, but these cells were still able to synthesize PHB at elevated rates and efficiency. When FP was continuously present in fed-batch culture, the yield in grams of polymer per gram of glucose consumed was calculated to range from 0.43 g/g, characteristic of nongrowing cells, to an unprecedented 0.65 g/g. Separation of an FP-free growth phase from an FP-containing growth phase in fed-batch culture resulted in better growth of these pleomorphic cells and good production of PHB (yield, 0.32 g/g). The fragility of these cells was exploited in a simple procedure for the extraction of high-molecular-weight PHB. The cells were treated with 1 N aqueous NH3 (pH 11.4) at 45°C for 10 min. This treatment removed about 10% of the non-PHB mass from the pellet, of which 60 to 77% was protein. The final product consisted of 94% PHB, 2% protein, and 4% nonprotein residual mass. The polymer molecular weight (1.7 × 106 to 2.0 × 106) and dispersity (1.0 to 1.9) were not significantly affected (P = 0.05) by this treatment. In addition, the NH3 extraction waste

  4. A study on the prevalence of Aeromonas spp. and its enterotoxin genes in samples of well water, tap water, and bottled water

    PubMed Central

    Didugu, Hareesh; Thirtham, Madhavarao; Nelapati, Krishnaiah; Reddy, K Kondal; Kumbhar, Baba Saheb; Poluru, Anusha; Pothanaboyina, Guruvishnu

    2015-01-01

    Aim: The aim of this work was to study the prevalence of Aeromonas spp. and its enterotoxin genes in various water sources. Materials and Methods: 125 samples (50 from well water, 50 from tap water, and 25 from bottled water) were collected from various sources in and around Greater Hyderabad Municipal Corporation and examined for the presence of aeromonads by both cultural and polymerase chain reaction (PCR) assay. Alkaline peptone water with ampicillin was used as enrichment. Aeromonas isolation medium and ampicillin dextrin agar were used as selective media. The boiling and snap chilling method was used for DNA extraction. Primers targeted against 16S rRNA, aer, and ast were used to identify aeromonads and its enterotoxins. Results: 48%, 18%, and 12% of well water, tap water, and bottled water samples were found positive by cultural assay with an overall prevalence of 28.8%. Aeromonads were detected in 32 % (52% in well water, 20% in tap water, and 16% in bottled water) of samples by PCR assay. Aerolysin (aer) gene was noticed in 34.6%, 20%, and 0% of well water, tap water, and bottled water samples, respectively, with an overall prevalence of 27.5%. Thermostable cytotonic enterotoxin (ast) was observed in 37.5% (42.3% in well water, 30% in tap water, and 25% in bottled mineral water) of samples. Conclusions: Presence of aeromonads and its toxin genes in various sources of water is of public health concern and emphasizes the need for necessary preventive measures to tackle the problem. PMID:27047024

  5. Performed surfactant-optimized aqueous alkaline flood

    SciTech Connect

    Thigpen, D.R.; Lawson, J.B.; Nelson, R.C.

    1991-11-26

    This paper describes improvement in a process for recovering oil from an acidic oil reservoir by injecting an aqueous alkaline solution comprising water, sodium chloride, and alkaline material for reacting with the reservoir oil forming a petroleum acid soap to form an in-situ surfactant system. The improvement comprises: selecting a preformed cosurfactant which is soluble in both the aqueous solution and the reservoir oil and has a solubility ratio which is grater than the solubility ratio of the petroleum acid soap where the solubility ratio is the ratio of solubility in the aqueous alkaline solution to the solubility in the reservoir oil; combining with the alkaline solution an amount of the preformed cosurfactant which will result in the in-situ surfacant system having a salinity about equal to a salinity which results in minimal interfacial tension between the oil in the reservoir and the in-situ surfactant system at reservoir temperature, wherein the amount of the preformed cosurfactant is about 0.3 percent by weight in the aqueous alkaline solution; and injecting the cosurfactant-aqueous alkaline solution mixture into the reservoir to displace oil toward a fluid production location.

  6. Solar light (hv) and H2O2/hv photo-disinfection of natural alkaline water (pH 8.6) in a compound parabolic collector at different day periods in Sahelian region.

    PubMed

    Ndounla, J; Pulgarin, C

    2015-11-01

    The photo-disinfection of natural alkaline surface water (pH 8.6 ± 0.3) for drinking purposes was carried out under solar radiation treatments. The enteric bacteria studied were the wild total coliforms/Escherichia coli (10(4) CFU/ml) and Salmonella spp. (10(4) CFU/ml) naturally present in the water. The photo-disinfection of a 25-l water sample was carried out in a solar compound parabolic collector (CPC) in the absence and in the presence of hydrogen peroxide (H2O2). The addition of H2O2 (10 mg/L) to the sample water was sufficient to enhance the photo-disinfection and ensure an irreversible lethal action on the wild enteric bacteria contents of the sample. The inactivation kinetic of the system was significantly enhanced compared to the one carried out without H2O2 addition. The effect of the solar radiation parameters on the efficiency of the photo-disinfection were assessed. The pH has increased during the treatment in all the photo-disinfection processes (hv and H2O2/hv). The Salmonella spp strain has shown the best effective inactivate time in alkaline water than the one recorded under acidic or near-neutral conditions. The evolution of some physico-chemical parameters of the water (turbidity, NO2(-), NO3(-), NH4(+), HPO4(2-), and bicarbonate (HCO3(-))) was monitored during the treatment. Finally, the possible mechanistic process involved during the enteric bacteria inactivation was suggested.

  7. Inexpensive cross-linked polymeric separators made from water-soluble polymers. [for secondary alkaline nickel-zinc and silver-zinc cells

    NASA Technical Reports Server (NTRS)

    Hsu, L.-C.; Sheibley, D. W.

    1982-01-01

    Polyvinyl alcohol (PVA), cross-linked chemically with aldehyde reagents, produces membranes which demonstrate oxidation resistance, dimensional stability, low ionic resistivity (less than 0.8 Ohms sq cm), low zincate diffusivity (less than 1 x 10 to the -7th mols/sq cm per min), and low zinc dendrite penetration rate (greater than 350 min) which make them suitable for use as alkaline battery separators. They are intrinsically low in cost, and environmental health and safety problems associated with commercial production appear minimal. Preparation, property measurements, and cell test results in Ni/Zn and Ag/Zn cells are described and discussed.

  8. Alkaline flooding injection strategy

    SciTech Connect

    French, T.R.; Josephson, C.B.

    1992-03-01

    The objective of this project is to improved alkali-surfactant flooding methods, and this includes determining the proper design of injection strategy. Several different injection strategies have been used or suggested for recovering heavy oils with surfactant-enhanced alkaline flooding methods. Oil recovery was compared for four different injection strategies: (1) surfactant followed by polymer, (2) surfactant followed by alkaline polymer, (3) alkaline surfactant followed by polymer, and (4) alkali, surfactant, and polymer mixed in a single formulation. The effect of alkaline preflush was also studied under two different conditions. All of the oil recovery experiments were conducted under optimal conditions with a viscous, non-acidic oil from Hepler (KS) oil field. The coreflood experiments were conducted with Berea sandstone cores since field core was not available in sufficient quantity for coreflood tests. The Tucker sand of Hepler field is a Class I fluvial dominated deltaic reservoir, as classified by the Department of Energy, which has been selected as the site of a DOE-sponsored field pilot test.

  9. Diclofenac salts. III. Alkaline and earth alkaline salts.

    PubMed

    Fini, Adamo; Fazio, Giuseppe; Rosetti, Francesca; Angeles Holgado, M; Iruín, Ana; Alvarez-Fuentes, Josefa

    2005-11-01

    Diclofenac salts containing the alkaline and two earth alkaline cations have been prepared and characterized by scanning electron microscopy (SEM) and EDAX spectroscopy; and by thermal and thermogravimetric analysis (TGA): all of them crystallize as hydrate when precipitated from water. The salts dehydrate at room temperature and more easily on heating, but recovery the hydration, when placed in a humid environment. X-ray diffraction spectra suggest that on dehydration new peaks appear on diffractograms and the lattice of the salts partially looses crystallinity. This phenomenon is readily visible in the case of the calcium and magnesium salts, whose thermograms display a crystallization exotherm, before melting or decomposing at temperatures near or above 200 degrees C; these last salts appear to form solvates, when prepared from methanol. The thermogram of each salt shows a complex endotherm of dehydration about 100 degrees C; the calcium salt displays two endotherms, well separated at about 120 and 160 degrees C, which disappear after prolonged heating. Decomposition exotherms, before or soon after the melting, appear below 300 degrees C. The ammonium salt is thermally unstable and, when heated to start dehydration, dissociates and leaves acidic diclofenac.

  10. Sorption of water alkalinity and hardness from high-strength wastewater on bifunctional activated carbon: process optimization, kinetics and equilibrium studies.

    PubMed

    Amosa, Mutiu K

    2016-08-01

    Sorption optimization and mechanism of hardness and alkalinity on bifunctional empty fruit bunch-based powdered activation carbon (PAC) were studied. The PAC possessed both high surface area and ion-exchange properties, and it was utilized in the treatment of biotreated palm oil mill effluent. Batch adsorption experiments designed with Design Expert(®) were conducted in correlating the singular and interactive effects of the three adsorption parameters: PAC dosage, agitation speed and contact time. The sorption trends of the two contaminants were sequentially assessed through a full factorial design with three factor interaction models and a central composite design with polynomial models of quadratic order. Analysis of variance revealed the significant factors on each design response with very high R(2) values indicating good agreement between model and experimental values. The optimum operating conditions of the two contaminants differed due to their different regions of operating interests, thus necessitating the utility of desirability factor to get consolidated optimum operation conditions. The equilibrium data for alkalinity and hardness sorption were better represented by the Langmuir isotherm, while the pseudo-second-order kinetic model described the adsorption rates and behavior better. It was concluded that chemisorption contributed majorly to the adsorption process.

  11. Alkaline detergent recycling via ultrafiltration

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-06-01

    The metal finishing industry uses alkaline cleaners and detergents to remove oils and dirt from manufactured parts, often before they are painted or plated. The use of these cleaners has grown because environmental regulations are phasing out ozone depleting substances and placing restrictions on the use and disposal of many hazardous solvents. Lawrence Livermore National Laboratory is examining ultrafiltration as a cleaning approach that reclaims the cleaning solutions and minimizes wastes. The ultrafiltration membrane is made from sheets of polymerized organic film. The sheets are rolled onto a supporting frame and installed in a tube. Spent cleaning solution is pumped into a filter chamber and filtered through the membrane that captures oils and dirt and allows water and detergent to pass. The membrane is monitored and when pressure builds from oil and dirt, an automatic system cleans the surface to maintain solution flow and filtration quality. The results show that the ultrafiltration does not disturb the detergent concentration or alkalinity but removed almost all the oils and dirt leaving the solution in condition to be reused.

  12. Alkaline quinone flow battery.

    PubMed

    Lin, Kaixiang; Chen, Qing; Gerhardt, Michael R; Tong, Liuchuan; Kim, Sang Bok; Eisenach, Louise; Valle, Alvaro W; Hardee, David; Gordon, Roy G; Aziz, Michael J; Marshak, Michael P

    2015-09-25

    Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecules that are composed entirely of Earth-abundant elements and are nontoxic, nonflammable, and safe for use in residential and commercial environments. The battery operates efficiently with high power density near room temperature. These results demonstrate the stability and performance of redox-active organic molecules in alkaline flow batteries, potentially enabling cost-effective stationary storage of renewable energy.

  13. ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS - ALKALINE HYDROLYSIS

    EPA Science Inventory

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to allow the calculation of alkaline hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition state...

  14. ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS. I. ALKALINE HYDROLYSIS

    EPA Science Inventory

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to allow the calculation of alkaline hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition state...

  15. Comparison of isolation of Haemophilus vaginalis (Corynebacterium vaginale) from peptone-starch-dextrose agar and Columbia colistin-nalidoxic acid agar.

    PubMed Central

    Golberg, R L; Washington JA, I I

    1976-01-01

    A total of 447 cervical or vaginal specimens were inoculated in parallel onto peptone-starch-dextrose (PSD) and Columbia colistin (10 mg/ml)-nalidixic acid (15 mug/ml) (CNA) agar and were incubated for 48 h at 35 degrees C in an atmosphere with 2 to 10% CO2. One hundred (22.4%) of the cultures were positive for Haemophilus vaginalis. Forty-eight of the isolates were recovered from both PSD and Columbia CNA agar, five from PSD only, and 47 from Columbia CNA agar only (P less than 0.001). On Columbia CNA agar, 76 of the isolates were detected after 24 h of incubation, and the remainder were detected within 4 days of incubation. PMID:1085777

  16. A chronoamperometric screen printed carbon biosensor based on alkaline phosphatase inhibition for W(IV) determination in water, using 2-phospho-L-ascorbic acid trisodium salt as a substrate.

    PubMed

    Alvarado-Gámez, Ana Lorena; Alonso-Lomillo, María Asunción; Domínguez-Renedo, Olga; Arcos-Martínez, María Julia

    2015-01-22

    This paper presents a chronoamperometric method to determine tungsten in water using screen-printed carbon electrodes modified with gold nanoparticles and cross linked alkaline phosphatase immobilized in the working electrode. Enzymatic activity over 2-phospho-l-ascorbic acid trisodium salt, used as substrate, was affected by tungsten ions, which resulted in a decrease of chronoamperometric current, when a potential of 200 mV was applied on 10 mM of substrate in a Tris HCl buffer pH 8.00 and 0.36 M of KCl. Calibration curves for the electrochemical method validation, give a reproducibility of 5.2% (n = 3), a repeatability of 9.4% (n = 3) and a detection limit of 0.29 ± 0.01 µM. Enriched tap water, purified laboratory water and bottled drinking water, with a certified tungsten reference solution traceable to NIST, gave a recovery of 97.1%, 99.1% and 99.1% respectively (n = 4 in each case) and a dynamic range from 0.6 to 30 µM. This study was performed by means of a Lineweaver-Burk plot, showing a mixed kinetic inhibition.

  17. A Chronoamperometric Screen Printed Carbon Biosensor Based on Alkaline Phosphatase Inhibition for W(VI) Determination in Water, Using 2-Phospho-l-Ascorbic Acid Trisodium Salt as a Substrate

    PubMed Central

    Alvarado-Gámez, Ana Lorena; Alonso-Lomillo, María Asunción; Domínguez-Renedo, Olga; Arcos-Martínez, María Julia

    2015-01-01

    This paper presents a chronoamperometric method to determine tungsten in water using screen-printed carbon electrodes modified with gold nanoparticles and cross linked alkaline phosphatase immobilized in the working electrode. Enzymatic activity over 2-phospho-l-ascorbic acid trisodium salt, used as substrate, was affected by tungsten ions, which resulted in a decrease of chronoamperometric current, when a potential of 200 mV was applied on 10 mM of substrate in a Tris HCl buffer pH 8.00 and 0.36 M of KCl. Calibration curves for the electrochemical method validation, give a reproducibility of 5.2% (n = 3), a repeatability of 9.4% (n = 3) and a detection limit of 0.29 ± 0.01 μM. Enriched tap water, purified laboratory water and bottled drinking water, with a certified tungsten reference solution traceable to NIST, gave a recovery of 97.1%, 99.1% and 99.1% respectively (n = 4 in each case) and a dynamic range from 0.6 to 30 μM. This study was performed by means of a Lineweaver–Burk plot, showing a mixed kinetic inhibition. PMID:25621602

  18. Evaluation of a membrane biological reactor for reclaiming water, alkalinity, salts, phosphorus, and protein contained in a high-strength aquacultural wastewater.

    PubMed

    Sharrer, Mark J; Rishel, Kata; Summerfelt, Steven T

    2010-06-01

    The capacity of a membrane biological reactor to provide nitrification, denitrification, and enhanced biological phosphorus removal of a high-strength aquaculture backwash flow (control condition), or the same flow amended with 100mg/L of NO(3)-N and 3mg/L of dissolved P (test condition), was assessed using only endogenous carbon. Permeate TSS and cBOD(5) concentrations were <1mg/L under control and test conditions, achieving 99.97-100% removal efficiencies, respectively. Permeate TN concentrations were 1.8+/-0.5mg/L and 2.1+/-1.4 mg/L, while permeate TP concentrations were 0.05+/-0.01 mg/L and 0.10+/-0.03 mg/L, respectively, under control and test conditions. Our findings suggest that permeate flow could be reclaimed to recycle alkalinity, salts, and heat for fish culture and that the waste activated sludge does not produce metals concentrations that would prevent its land application (reclaiming phosphorus) or prevent its use as a protein source in animal feeds.

  19. Chemical analysis of new water-soluble (1→6)-, (1→4)-α, β-glucan and water-insoluble (1→3)-, (1→4)-β-glucan (Calocyban) from alkaline extract of an edible mushroom, Calocybe indica (Dudh Chattu).

    PubMed

    Mandal, Soumitra; Maity, Kankan K; Bhunia, Sanjoy K; Dey, Biswajit; Patra, Sukesh; Sikdar, Samir R; Islam, Syed S

    2010-12-10

    Two different glucans (PS-I, water-soluble; and PS-II, water-insoluble) were isolated from the alkaline extract of fruit bodies of an edible mushroom Calocybe indica. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR analysis ((1)H, (13)C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of these polysaccharides were established as: PS-I: →6)-β-D-Glcp-(1→6)-β-D-glcp-(1→6)-)-β-D-Glcp-(1→ α-D=Glcp (Water-soluble glucan). PS-II: →3)-β-D-Glcp-(1→3)-β-D-glcp-(1→3)-)-β-D-Glcp-(1→3)-β-D-Glcp-(1→ β-D-Glcp (Water-insoluble glucan, Calocyban).

  20. Alkaline post-treatment of Cd(II)-glutathione coordination polymers: toward green synthesis of water-soluble and cytocompatible CdS quantum dots with tunable optical properties.

    PubMed

    Huang, Pengcheng; Jiang, Qin; Yu, Ping; Yang, Lifen; Mao, Lanqun

    2013-06-12

    In this study, we demonstrate a facile and environmentally friendly method for the synthesis of glutathione (GSH)-capped water-soluble CdS quantum dots (QDs) with a high cytocompatibility and a tunable optical property based on alkaline post-treatment of Cd-GSH coordination polymers (CPs). Cd-GSH CPs are synthesized with the coordination reaction of Cd(2+) with GSH at different pH values, and the CdS QDs are then formed by adding NaOH to the aqueous dispersion of the Cd-GSH CPs to break the coordination interaction between Cd(2+) and GSH with the release of sulfur. The particle size and optical property of the as-formed CdS QDs are found to be easily tailored by simply adjusting the starting pH values of GSH solutions used for the formation of Cd-GSH CPs, in which the wavelengths of trap-state emission of the QDs red-shift with an increase in the sizes of the QDs that is caused by an increase in the starting pH values of GSH solutions. In addition, the use of GSH as the capping reagent eventually endows the as-formed CdS QDs with enhanced water solubility and good cytocompatibility, as demonstrated with HeLa cells. The method demonstrated here is advantageous in that the cadmium precursor and the sulfur source are nontoxic and easily available, and the size, optical properties, water solubility, and cytocompatibilty of the as-formed CdS QDs are simply achieved and experimentally regulated. This study offers a new and green synthetic route to water-soluble and cytocompatible CdS QDs with tunable optical properties.

  1. Triplex reverse transcription-PCR for detecting viable toxigenic Vibrio cholerae in water samples in Thailand.

    PubMed

    Kanoktippornchai, Boonnapa; Chomvarin, Chariya; Engchanil, Chulapan; Wongboot, Warawan

    2014-03-01

    Abstract. Detection of toxigenic Vibrio cholerae O1/O139 in aquatic environment is difficult to achieve using the culture method. For direct detection of viable toxigenic V. cholerae in aquatic environment, we developed a triplex reverse transcription (RT)-PCR, targeting genes for the outer membrane protein (ompW), cholera toxin A (ctxA) and toxin-coregulated pilli (tcpA) and compared the assay with the culture method. After enrichment of the bacteria-containing filters in alkaline peptone water for 6 hours, the sensitivity of triplex RT-PCR for detecting V. cholerae was 7 cfu/ml. Of the 80 environmental water samples collected from various regions in Northeast Thailand, triplex RT-PCR detected 15 toxigenic and 20 non-toxigenic V. cholerae, whereas the culture method detected only 3 toxigenic V. cholerae--containing water samples. These results show that this triplex RT-PCR method could be used as an alternative tool for rapid and sensitive identification of viable toxigenic V cholerae in environmental water samples.

  2. The sulphate-reduction alkalinity pump tested

    NASA Astrophysics Data System (ADS)

    Meister, Patrick; Petrishcheva, Elena

    2016-04-01

    Carbonate precipitation has been suggested to be induced by alkalinity increase during sulphate reduction under anoxic conditions. This mechanism may explain the formation of carbonate deposits in shallow marine environments, either within a redox stratified sediment inhabited by phototrophic microbial mats or in shallow water within the photic zone where sulphidic water is upwelling onto the shelf. The alkalinity pump may work as long as the sulphide is not reoxidized to sulphate, a process that would acidify the surrounding. The alkalinity effect of sulphate reduction was recently tested by Aloisi (2008) for microbial mats using a model approach. He found that sulphate reduction does not significantly increase or even decrease carbonate saturation and is unlikely to have played a significant role through Earth history. The model considers many environmental factors, including the effect of carbonate precipitation itself on the carbonate equilbrium and on the alkalinity. We used a modified version of Aloisi's (2008) model to simulate the saturation states of aragonite, calcite and dolomite without the effects of carbonate precipitation. This is necessary to evaluate the effect of microbial metabolisms exclusively on carbonate saturation, since carbonate precipitation is only the consequence, but not the cause of oversaturation. First results show that the saturation state is increased in the zone of phototrophic CO2 uptake. In contrast, the saturation state is strongly decreased in the zone where dissolved oxygen overlaps with dissolved sulphide. Aerobic sulphide oxidation consumes most of the HS- and dissipates most of the alkalinity produced in the sulphate reduction zone below. Hence, our results are consistent with the findings of Aloisi (2008), and they even more clearly show that sulphate reduction does not induce carbonate precipitation nor contributes to carbonate precipitation in combination with phototrophic CO2 uptake. The alkalinity effect of sulphate

  3. The importance of catchment vegetation for alkalinity, phosphorus burial and macrophytes as revealed by a recent paleolimnological study in a soft water lake.

    PubMed

    Klamt, Anna-Marie; Jensen, Henning S; Mortensen, Morten F; Schreiber, Norman; Reitzel, Kasper

    2017-02-15

    The land use within a catchment may markedly affect the environmental conditions in a lake and the storage capability of its sediments. This study investigated how changes in the dominant catchment vegetation (from local stands of deciduous trees over extensive heathland with some agriculture to mainly coniferous forest) occurring during the last ca. 200years were reflected in the sediments of a soft water lake and how these changes influenced the lake ecosystem. Pollen, macrofossils, metals, different phosphorus (P) forms, organic matter, carbon and nitrogen contents were determined in short sediment cores. This novel combination of proxies revealed that 1) the reduction of deciduous trees in the watershed seemingly reduced the calcium (Ca) supply to the lake and thereby its buffering capacity. This development was accompanied by decreased abundances of Ca-dependent species and subsequent increases in acidophilic species. 2) The sedimentary contents of organic matter, non-reactive P and humic-bound P were evidently higher in sediments deposited during the time when deciduous trees were abundant, which is probably linked to a stabilising effect by Ca. 3) An erosion event clearly reduced the amounts of macrofossils of isoetid species and characeans, indicating a reduction in their maximum distribution depth because of lower water transparency. Overall, the results of our paleolimnological study are of importance within lake management by convincingly showing how land use changes may (irreversibly) affect environmental conditions and species composition in soft water lakes and the storage of organic matter and P in their sediments.

  4. Alkaline battery, separator therefore

    NASA Technical Reports Server (NTRS)

    Schmidt, George F. (Inventor)

    1980-01-01

    An improved battery separator for alkaline battery cells has low resistance to electrolyte ion transfer and high resistance to electrode ion transfer. The separator is formed by applying an improved coating to an electrolyte absorber. The absorber, preferably, is a flexible, fibrous, and porous substrate that is resistant to strong alkali and oxidation. The coating composition includes an admixture of a polymeric binder, a hydrolyzable polymeric ester and inert fillers. The coating composition is substantially free of reactive fillers and plasticizers commonly employed as porosity promoting agents in separator coatings. When the separator is immersed in electrolyte, the polymeric ester of the film coating reacts with the electrolyte forming a salt and an alcohol. The alcohol goes into solution with the electrolyte while the salt imbibes electrolyte into the coating composition. When the salt is formed, it expands the polymeric chains of the binder to provide a film coating substantially permeable to electrolyte ion transfer but relatively impermeable to electrode ion transfer during use.

  5. From highly polluted Zn-rich acid mine drainage to non-metallic waters: implementation of a multi-step alkaline passive treatment system to remediate metal pollution.

    PubMed

    Macías, Francisco; Caraballo, Manuel A; Rötting, Tobias S; Pérez-López, Rafael; Nieto, José Miguel; Ayora, Carlos

    2012-09-01

    Complete metal removal from highly-polluted acid mine drainage was attained by the use of a pilot multi-step passive remediation system. The remediation strategy employed can conceptually be subdivided into a first section where the complete trivalent metal removal was achieved by the employment of a previously tested limestone-based passive remediation technology followed by the use of a novel reactive substrate (caustic magnesia powder dispersed in a wood shavings matrix) obtaining a total divalent metal precipitation. This MgO-step was capable to abate high concentrations of Zn together with Mn, Cd, Co and Ni below the recommended limits for drinking waters. A reactive transport model anticipates that 1 m(3) of MgO-DAS (1 m thick × 1 m(2) section) would be able to treat a flow of 0.5 L/min of a highly acidic water (total acidity of 788 mg/L CaCO(3)) for more than 3 years.

  6. Cation exchange properties of zeolites in hyper alkaline aqueous media.

    PubMed

    Van Tendeloo, Leen; de Blochouse, Benny; Dom, Dirk; Vancluysen, Jacqueline; Snellings, Ruben; Martens, Johan A; Kirschhock, Christine E A; Maes, André; Breynaert, Eric

    2015-02-03

    Construction of multibarrier concrete based waste disposal sites and management of alkaline mine drainage water requires cation exchangers combining excellent sorption properties with a high stability and predictable performance in hyper alkaline media. Though highly selective organic cation exchange resins have been developed for most pollutants, they can serve as a growth medium for bacterial proliferation, impairing their long-term stability and introducing unpredictable parameters into the evolution of the system. Zeolites represent a family of inorganic cation exchangers, which naturally occur in hyper alkaline conditions and cannot serve as an electron donor or carbon source for microbial proliferation. Despite their successful application as industrial cation exchangers under near neutral conditions, their performance in hyper alkaline, saline water remains highly undocumented. Using Cs(+) as a benchmark element, this study aims to assess the long-term cation exchange performance of zeolites in concrete derived aqueous solutions. Comparison of their exchange properties in alkaline media with data obtained in near neutral solutions demonstrated that the cation exchange selectivity remains unaffected by the increased hydroxyl concentration; the cation exchange capacity did however show an unexpected increase in hyper alkaline media.

  7. An alkaline one-pot reaction to synthesize luminescent Eu-BTC MOF nanorods, highly pure and water-insoluble, under room conditions

    NASA Astrophysics Data System (ADS)

    Medina-Velazquez, D. Y.; Alejandre-Zuniga, B. Y.; Loera-Serna, S.; Ortiz, E. M.; Morales-Ramirez, A. de J.; Garfias-Garcia, E.; Garcia-Murillo, A.; Falcony, C.

    2016-12-01

    The increasing demand for optoelectronic devices requires the development of luminescent materials with high luminescence efficiency and low energy demands, and the metalorganic frameworks (MOFs) with lanthanides ions offer great potential in this area. The metalorganic materials provide properties of flexibility, low density, low-cost methods of synthesis, and insolubility in water, which gives them an advantage over traditional phosphors. In this study, a benzenetricarboxylate ligand (BTC) with a Eu3+ MOF was synthesized, and its structural and luminescent properties were measured. The metalorganic compound was generated in a one-pot reaction from europium nitrate and trimesic acid precursors. Through characterization by X-ray diffraction powder, infrared spectroscopy, SEM structural characterization, and luminescent spectroscopy, the formation of Europium benzenetricarboxylate (Eu-BTC) MOF nanorods was tested and the calculated value was in the range of 30-60 nm. A red luminescent emission with high intensity was observed for all the procedures.

  8. Processes affecting the oceanic distributions of dissolved calcium and alkalinity

    SciTech Connect

    Shiller, A.M.; Gieskes, J.M.

    1980-05-20

    Recent studies of the CO/sub 2/ system have suggested that chemical processes in addition to the dissolution and precipitation of calcium carbonate affect the oceanic calcium and alkalinity distributions. Calcium and alkalinity data from the North Pacific have been examined both by using the simple physical-chemical model of previous workers and by a study involving the broader oceanographic context of these data. The simple model is shown to be an inadequate basis for these studies. Although a proton flux associated with organic decomposition may affect the alkalinity, previously reported deviations of calcium-alkalinity correlations from expected trends appear to be related to boundary processes that have been neglected rather than to this proton flux. The distribution of calcium in the surface waters of the Pacific Ocean is examined.

  9. The effects of alkalinity and acidity of process water and hydrochar washing on the adsorption of atrazine on hydrothermally produced hydrochar.

    PubMed

    Flora, Justine F R; Lu, Xiaowei; Li, Liang; Flora, Joseph R V; Berge, Nicole D

    2013-11-01

    Hydrothermal carbonization of simulated food waste was performed at 250 °C for 20 h using deionized water (DI) and 0.01 N solutions of HCl, NaCl, and NaOH. The hydrochars produced were washed with acetone and the adsorptive capacity of the washed and unwashed hydrochars for atrazine were characterized. Using a generalized linear model, it was shown that the adsorptive capacity of the washed hydrochar was significantly higher than that of the unwashed hydrochars. The HCl processed unwashed hydrochar has a slightly higher adsorptive capacity compared to the DI processed hydrochar while both the NaOH processed washed and unwashed hydrochars were slightly lower than the corresponding DI processed hydrochars. (13)C solid-state NMR results showed no discernible differences in surface functional groups among the washed hydrochars and among the unwashed hydrochars. A clear decrease in alkyl groups and an increase in aromatic/olefinic-C groups were observed after acetone washing. (1)H liquid-phase NMR showed carbon alkyl chains were present in the acetone wash. Interaction energies calculated using dispersion corrected density functional theory show that atrazine is more strongly adsorbed to surfaces without weakly associated alkyl groups.

  10. Facile electrochemical co-deposition of a graphene-cobalt nanocomposite for highly efficient water oxidation in alkaline media: direct detection of underlying electron transfer reactions under catalytic turnover conditions.

    PubMed

    Guo, Si-Xuan; Liu, Yuping; Bond, Alan M; Zhang, Jie; Esakki Karthik, P; Maheshwaran, I; Senthil Kumar, S; Phani, K L N

    2014-09-21

    A facile electrochemical co-deposition method has been developed for the fabrication of graphene-cobalt nanocomposite modified electrodes that achieve exceptionally efficient water oxidation in highly alkaline media. In the method reported, a graphene-cobalt nanocomposite film was deposited electrochemically from a medium containing 1 mg ml(-1) graphene oxide, 0.8 mM cobalt nitrate and 0.05 M phytic acid (pH 7). The formation of the nanocomposite film was confirmed using electrochemical, Raman spectroscopic and scanning electron microscopic techniques. The nanocomposite film exhibits excellent activity and stability towards water oxidation to generate oxygen in 1 M NaOH aqueous electrolyte media. A turn over frequency of 34 s(-1) at an overpotential of 0.59 V and a faradaic efficiency of 97.7% were deduced from analysis of data obtained by rotating ring disk electrode voltammetry. Controlled potential electrolysis data suggests that the graphene supported catalyst exhibits excellent stability under these harsh conditions. Phytate anion acts as stabilizer for the electrochemical formation of cobalt nanoparticles. Fourier transformed ac voltammetry allowed the redox chemistry associated with catalysis to be detected directly under catalytic turnover conditions. Estimates of formal reversible potentials obtained from this method and derived from the overall reactions 3Co(OH)2 + 2OH(-) ⇌ Co3O4 + 4H2O + 2e(-), Co3O4 + OH(-) ⇌ 3CoOOH + e(-) and CoOOH + OH(-) ⇌ CoO2 + H2O + e(-) are 0.10, 0.44 and 0.59 V vs. Ag/AgCl, respectively.

  11. Net alkalinity and net acidity 2: Practical considerations

    USGS Publications Warehouse

    Kirby, C.S.; Cravotta, C.A.

    2005-01-01

    The pH, alkalinity, and acidity of mine drainage and associated waters can be misinterpreted because of the chemical instability of samples and possible misunderstandings of standard analytical method results. Synthetic and field samples of mine drainage having various initial pH values and concentrations of dissolved metals and alkalinity were titrated by several methods, and the results were compared to alkalinity and acidity calculated based on dissolved solutes. The pH, alkalinity, and acidity were compared between fresh, unoxidized and aged, oxidized samples. Data for Pennsylvania coal mine drainage indicates that the pH of fresh samples was predominantly acidic (pH 2.5-4) or near neutral (pH 6-7); ??? 25% of the samples had pH values between 5 and 6. Following oxidation, no samples had pH values between 5 and 6. The Standard Method Alkalinity titration is constrained to yield values >0. Most calculated and measured alkalinities for samples with positive alkalinities were in close agreement. However, for low-pH samples, the calculated alkalinity can be negative due to negative contributions by dissolved metals that may oxidize and hydrolyze. The Standard Method hot peroxide treatment titration for acidity determination (Hot Acidity) accurately indicates the potential for pH to decrease to acidic values after complete degassing of CO2 and oxidation of Fe and Mn, and it indicates either the excess alkalinity or that required for neutralization of the sample. The Hot Acidity directly measures net acidity (= -net alkalinity). Samples that had near-neutral pH after oxidation had negative Hot Acidity; samples that had pH < 6.3 after oxidation had positive Hot Acidity. Samples with similar pH values before oxidation had dissimilar Hot Acidities due to variations in their alkalinities and dissolved Fe, Mn, and Al concentrations. Hot Acidity was approximately equal to net acidity calculated based on initial pH and dissolved concentrations of Fe, Mn, and Al minus the

  12. Application of maize tassel for the removal of Pb, Se, Sr, U and V from borehole water contaminated with mine wastewater in the presence of alkaline metals.

    PubMed

    Zvinowanda, Caliphs M; Okonkwo, Jonathan O; Sekhula, Mahlatse M; Agyei, Nana M; Sadiku, Rotimi

    2009-05-30

    In this study, the removal of Pb(II) from aqueous solutions by tassel powder was studied and optimised. Batch experiments were conducted on simulated solutions using tassel powder adsorbent and the effects of contact time, pH and concentration on the extent of Pb (II) removal was studied. Equilibrium and kinetic models for Pb(II) sorption were developed by considering the effect of contact time and concentration at optimum pH 4 and fixed temperature(25 degrees C). The Freundlich model was found to describe the sorption energetics of Pb(II) on tassel more fully than the Langmuir. A maximum Pb(II) loading capacity of 333.3mg/g on tassel was obtained. The adsorption process could be well described by both the Langmuir and Freundlich isotherms with R(2) values of 0.957 and 0.972, respectively. The kinetic parameters were obtained by fitting data from the effect of contact time on adsorption capacity into the pseudo-first, pseudo-second-order and intra-particle diffusion equations. The kinetics of Pb(II) on tassel surface was well defined using linearity coefficients (R(2)) by pseudo-second-order (0.999), followed by pseudo-first-order (0.795) and lastly intra-particle diffusion (0.6056), respectively. The developed method was then applied to environmental samples taken from borehole waters contaminated with mine wastewater. The removal of Pb (ND-100%), Se (100%), Sr (5.41-59.0%), U (100%) and V (46.1-100%) was attained using tassel. The uptake of the metals from environmental samples was dependent on pH, ionic strength and levels of other competing species.

  13. Separation and characterization of mares' milk alpha(s1)-, beta-, kappa-caseins, gamma-casein-like, and proteose peptone component 5-like peptides.

    PubMed

    Egito, A S; Miclo, L; López, C; Adam, A; Girardet, J M; Gaillard, J L

    2002-04-01

    The equine alpha(s1)- and beta-caseins (CN) were purified by chromatography on DEAE-cellulose and by reversed-phase HPLC. The alpha(s1)-, beta-, and kappa-CN were characterized either by monodimensional urea-PAGE or sodium dodecylsulfate (SDS)-PAGE or by bidimensional electrophoresis. Kappa-casein was characterized after electrophoresis by glycoprotein-specific staining. To identify alpha(s1)-CN without ambiguity, internal sequences were determined after trypsin or chymosin digestion of purified alpha(s1)-CN. These sequences, that could be estimated to correspond to 62% of the full protein, presented strong identities with regions of alpha(s1)-CN primary structures of other species. In particular, 51, 48, 43, and 40% identities were obtained with corresponding regions of sow, dromedary, cow, and human alpha(s1)-CN, respectively. On the other hand, trace amounts of equine gamma-CN-like and proteose peptone component 5-like peptides were found in the whole CN. They were identified by microsequencing and corresponded to beta-CN peptides generated by plasmin action on the whole CN. The equine alpha(s1), beta-, and kappa-CN were separated by bidimensional electrophoresis in numerous isoelectric variants with apparent isoelectric points distributed between pH 4.4 to 6.3, 4.4 to 5.9, and 3.5 to 5.5, respectively. The beta- and kappa-CN displayed a more acidic character in the mare than in the cow.

  14. Inactivation of E. coli K12 in buffered peptone water and apple cider by pilot-plant scale supercritical carbon dioxide system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is increasing interest in non-thermal processing to inactivate foodborne pathogens and background microflora in juice products. Non-thermal pasteurization ensures safety and may offer better quality products than thermal pasteurization. Of non-thermal technologies, use of supercritical carbon ...

  15. The alkaline and alkaline-carbonatite magmatism from Southern Brazil

    NASA Astrophysics Data System (ADS)

    Ruberti, E.; Gomes, C. D. B.; Comin-Chiaramonti, P.

    2015-12-01

    Early to Late Cretaceous lasting to Paleocene alkaline magmatism from southern Brazil is found associated with major extensional structural features in and around the Paraná Basin and grouped into various provinces on the basis of several data. Magmatism is variable in size, mode of occurrence and composition. The alkaline rocks are dominantly potassic, a few occurrences showing sodic affinity. The more abundant silicate rocks are evolved undersaturated to saturated in silica syenites, displaying large variation in igneous forms. Less evolved types are restricted to subvolcanic environments and outcrops of effusive suites occur rarely. Cumulatic mafic and ultramafic rock types are very common, particularly in the alkali-carbonatitic complexes. Carbonatite bodies are represented by Ca-carbonatites and Mg-carbonatites and more scarcely by Fe-carbonatites. Available radiometric ages for the alkaline rocks fit on three main chronological groups: around 130 Ma, subcoveal with the Early Cretaceous flood tholeiites of the Paraná Basin, 100-110 Ma and 80-90 Ma (Late Cretaceous). The alkaline magmatism also extends into Paleocene times, as indicated by ages from some volcanic lavas. Geochemically, alkaline potassic and sodic rock types are distinguished by their negative and positive Nb-Ta anomalies, respectively. Negative spikes in Nb-Ta are also a feature common to the associated tholeiitic rocks. Sr-Nd-Pb systematics confirm the contribution of both HIMU and EMI mantle components in the formation of the alkaline rocks. Notably, Early and Late Cretaceous carbonatites have the same isotopic Sr-Nd initial ratios of the associated alkaline rocks. C-O isotopic Sr-Nd isotopic ratios indicate typical mantle signature for some carbonatites and the influence of post-magmatic processes in others. Immiscibility of liquids of phonolitic composition, derived from mafic alkaline parental magmas, has been responsible for the origin of the carbonatites. Close association of alkaline

  16. Thermodynamic model for an alkaline fuel cell

    NASA Astrophysics Data System (ADS)

    Verhaert, Ivan; De Paepe, Michel; Mulder, Grietus

    Alkaline fuel cells are low temperature fuel cells for which stationary applications, e.g. cogeneration in buildings, are a promising market. In order to guarantee a long life, water and thermal management has to be done in a careful way. In order to better understand the water, alkali and thermal flows, a two-dimensional model for an Alkaline Fuel Cell is developed using a control volume approach. In each volume the electrochemical reactions together with the mass and energy balance are solved. The model is created in Aspen Custom Modeller, the development environment of Aspen Plus, where special attention is given to the physical flow of hydrogen, water and air in the system. In this way the developed component, the AFC-cell, can be built into stack configurations to understand its effect on the overall performance. The model is validated by experimental data from measured performance by VITO with their Cell Voltage Monitor at a test case, where the AFC-unit is used as a cogeneration unit.

  17. Nitrogen isotope evidence for alkaline lakes on late Archean continents

    NASA Astrophysics Data System (ADS)

    Stüeken, E. E.; Buick, R.; Schauer, A. J.

    2015-02-01

    Nitrogen isotope ratios in ancient sedimentary rocks are generally interpreted as a proxy for metabolic nitrogen pathways and the redox state of the water column. Fractionation processes occurring under anoxic, alkaline conditions during the dissociation of NH4+ to H+ and volatile NH3 are frequently overlooked, although this mechanism imparts large isotopic fractionations. Here we propose that NH3 volatilization is largely responsible for δ15N values of up to + 50 ‰ at high C/N ratios in the late Archean Tumbiana Formation. This sequence of sedimentary rocks represents a system of lakes that formed on subaerial flood basalts and were partly filled by basaltic volcanic ash. Aqueous alteration of volcanic glass followed by evaporative concentration of ions should have led to the development of high alkalinity with a pH of 9 or higher, as in modern analogues. In this sedimentologically unusual setting, nitrogen isotope ratios thus provide indirect evidence for the oldest alkaline lake system in the rock record. These very heavy lacustrine δ15N values contrast markedly with those of Archean marine sedimentary rocks, making a Precambrian "soda ocean" unlikely. Today, alkaline lakes are among the most productive ecosystems on Earth. Some nutrients, in particular molybdenum, are more soluble at high pH, and certain prebiotic reactions would likely have been favored under alkaline conditions in similar settings earlier in Earth's history. Hence alkaline lakes in the Archean could have been significant for the origin and early evolution of life.

  18. Field measurement of alkalinity and pH

    USGS Publications Warehouse

    Barnes, Ivan

    1964-01-01

    The behavior of electrometric pH equipment under field conditions departs from the behavior predicted from Nernst's law. The response is a linear function of pH, and hence measured pH values may be corrected to true pH if the instrument is calibrated with two reference solutions for each measurement. Alkalinity titrations may also be made in terms of true pH. Standard methods, such as colorimetric titrations, were rejected as unreliable or too cumbersome for rapid field use. The true pH of the end point of the alkalinity titration as a function of temperature, ionic strength, and total alkalinity has been calculated. Total alkalinity in potable waters is the most important factor influencing the end point pH, which varies from 5.38 (0 ? C, 5 ppm (parts per million) HC0a-) to 4.32 (300 ppm HC0a-,35 ? C), for the ranges of variables considered. With proper precautions, the pH may be determined to =i:0.02 pH and the alkalinity to =i:0.6 ppm HCO3- for many naturally occurring bodies of fresh water.

  19. Alkalinity Analysis. Training Module 5.220.2.77.

    ERIC Educational Resources Information Center

    Bonte, John L.; Davidson, Arnold C.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with the acid-base titrimetric procedure for determining the hydroxide, carbonate and bicarbonate alkalinity of a water sample. Included are objectives, an instructor guide, student handouts and transparency masters. A video tape is also…

  20. Process of treating cellulosic membrane and alkaline with membrane separator

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1970-01-01

    The improvement of water-soluble cellulose ether membranes for use as separators in concentrated alkaline battery cells is discussed. The process of contacting membranes with an aqueous alkali solution of concentration less than that of the alkali solution to be used in the battery but above that at which the membrane is soluble is described.

  1. Alkalinity production in intertidal sands intensified by lugworm bioirrigation

    PubMed Central

    Rao, Alexandra M.F.; Malkin, Sairah Y.; Montserrat, Francesc; Meysman, Filip J.R.

    2014-01-01

    Porewater profiles and sediment-water fluxes of oxygen, nutrients, pH, calcium, alkalinity, and sulfide were measured in intertidal sandflat sediments from the Oosterschelde mesotidal lagoon (The Netherlands). The influence of bioturbation and bioirrigation by the deep-burrowing polychaete Arenicola marina on the rates and sources of benthic alkalinity generation was examined by comparing measurements in intact and defaunated sediment cores before and after the addition of A. marina in summer and fall 2011. Higher organic matter remineralization rates, shallower O2 penetration, and greater sediment-water solute fluxes were observed in summer, consistent with higher sediment community metabolic rates at a higher temperature. Lugworm activity stimulated porewater exchange (5.1 × in summer, 1.9 × in fall), organic matter remineralization (6.2 × in summer, 1.9 × in fall), aerobic respiration (2.4 × in summer, 2.1 × in fall), alkalinity release (4.7 × in summer, 4.0 × in fall), nutrient regeneration, and iron cycling. The effects of lugworm activity on net sediment-water fluxes were similar but more pronounced in summer than in fall. Alkalinity release in fall was entirely driven by metabolic carbonate dissolution, while this process explained between 22 and 69% of total alkalinity production in summer, indicating the importance of other processes in this season. By enhancing organic matter remineralization and the reoxidation of reduced metabolites by the sediment microbial community, lugworm activity stimulated the production of dissolved inorganic carbon and metabolic acidity, which in turn enhanced metabolic CaCO3 dissolution efficiency. In summer, evidence of microbial long distance electron transport (LDET) was observed in defaunated sediment. Thus, alkalinity production by net carbonate dissolution was likely supplemented by anaerobic respiration and LDET in summer. PMID:25431515

  2. Zinc electrode in alkaline electrolyte

    SciTech Connect

    McBreen, J.

    1995-12-31

    The zinc electrode in alkaline electrolyte is unusual in that supersaturated zincate solutions can form during discharge and spongy or mossy zinc deposits can form on charge at low overvoltages. The effect of additives on regular pasted ZnO electrodes and calcium zincate electrodes is discussed. The paper also reports on in situ x-ray absorption (XAS) results on mossy zinc deposits.

  3. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, David B.; Lao, Guifang

    1998-01-01

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium.

  4. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, D.B.; Lao, G.

    1998-01-06

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium. 3 figs.

  5. The Nickel(111)/Alkaline Electrolyte Interface

    NASA Technical Reports Server (NTRS)

    Wang, Kuilong; Chottiner, G. S.; Scherson, D. A.; Reid, Margaret A.

    1991-01-01

    The electrochemical properties of Ni (111) prepared and characterized in ultra high vacuum, UHV, by surface analytical techniques have been examined in alkaline media by cyclic voltammetry using an UHV-electrochemical cell transfer system designed and built in this laboratory. Prior to the transfer, the Ni(111) surfaces were exposed to saturation coverages of CO in UHV in an attempt to protect the surface from possible contamination with other gases during the transfer. Temperature Programmed Desorption, TPD, of CO-dosed Ni (111) surfaces displaying sharp c(4x2), LEED patterns, subsequently exposed to water-saturated Ar at atmospheric pressure in an auxiliary UHV compatible chamber and finally transferred back to the main UHV chamber, yielded CO2 and water as the only detectable products. This indicates that the CO-dosed surfaces react with water and/or bicarbonate and hydroxide as the most likely products. Based on the integration of the TPD peaks, the combined amounts of H2O and CO2 were found to be on the order of a single monolayer. The reacted c(4x2)CO/Ni(111) layer seems to protect the surface from undergoing spontaneous oxidation in strongly alkaline solutions. This was evidenced by the fact that the open circuit potential observed immediately after contact with deaerated 0.1 M KOH was about 0.38 V vs. DHE, drifting slightly towards more negative values prior to initiating the voltametric scans. The average ratio of the integrated charge obtained in the first positive linear scan in the range of 0.35 to 1.5 V vs. DHE (initiated at the open circuit potential) and the first (and subsequent) linear negative scans in the same solution yielded for various independent runs a value of 3.5 +/- 0.3. Coulometric analysis of the cyclic voltammetry curves indicate that the electrochemically formed oxyhydroxide layer involves a charge equivalent to 3.2 +/- 0.4 layers of Ni metal.

  6. The secondary alkaline zinc electrode

    NASA Astrophysics Data System (ADS)

    McLarnon, Frank R.; Cairns, Elton J.

    1991-02-01

    The worldwide studies conducted between 1975 and 1990 with the aim of improving cell lifetimes of secondary alkaline zinc electrodes are overviewed. Attention is given the design features and characteristics of various secondary alkaline zinc cells, including four types of zinc/nickel oxide cell designs (vented static-electrolyte, sealed static-electrolyte, vibrating-electrode, and flowing-electrolyte); two types of zinc/air cells (mechanically rechargeable consolidated-electrode and mechanically rechargeable particulate-electrode); zinc/silver oxide battery; zinc/manganese dioxide cell; and zinc/ferric cyanide battery. Particular consideration is given to recent research in the fields of cell thermodynamics, zinc electrodeposition, zinc electrodissolution, zinc corrosion, electrolyte properties, mathematical and phenomenological models, osmotic pumping, nonuniform current distribution, and cell cycle-life perforamnce.

  7. Development of alkaline fuel cells.

    SciTech Connect

    Hibbs, Michael R.; Jenkins, Janelle E.; Alam, Todd Michael; Janarthanan, Rajeswari; Horan, James L.; Caire, Benjamin R.; Ziegler, Zachary C.; Herring, Andrew M.; Yang, Yuan; Zuo, Xiaobing; Robson, Michael H.; Artyushkova, Kateryna; Patterson, Wendy; Atanassov, Plamen Borissov

    2013-09-01

    This project focuses on the development and demonstration of anion exchange membrane (AEM) fuel cells for portable power applications. Novel polymeric anion exchange membranes and ionomers with high chemical stabilities were prepared characterized by researchers at Sandia National Laboratories. Durable, non-precious metal catalysts were prepared by Dr. Plamen Atanassovs research group at the University of New Mexico by utilizing an aerosol-based process to prepare templated nano-structures. Dr. Andy Herrings group at the Colorado School of Mines combined all of these materials to fabricate and test membrane electrode assemblies for single cell testing in a methanol-fueled alkaline system. The highest power density achieved in this study was 54 mW/cm2 which was 90% of the project target and the highest reported power density for a direct methanol alkaline fuel cell.

  8. Priming effect of abscisic acid on alkaline stress tolerance in rice (Oryza sativa L.) seedlings.

    PubMed

    Wei, Li-Xing; Lv, Bing-Sheng; Wang, Ming-Ming; Ma, Hong-Yuan; Yang, Hao-Yu; Liu, Xiao-Long; Jiang, Chang-Jie; Liang, Zheng-Wei

    2015-05-01

    Saline-alkaline stress is characterized by high salinity and high alkalinity (high pH); alkaline stress has been shown to be the primary factor inhibiting rice seedling growth. In this study, we investigated the potential priming effect of abscisic acid (ABA) on tolerance of rice seedlings to alkaline stress simulated by Na2CO3. Seedlings were pretreated with ABA at concentrations of 0 (control), 10, and 50 μM by root-drench for 24 h and then transferred to a Na2CO3 solution that did not contain ABA. Compared to control treatment, pretreatment with ABA substantially improved the survival rate of rice seedlings and increased biomass accumulation after 7 days under the alkaline condition. ABA application at 10 μM also alleviated the inhibitory effects of alkaline stress on the total root length and root surface area. Physiologically, ABA increased relative water content (RWC) and decreased cell membrane injury degree (MI) and Na(+)/K(+) ratios. In contrast, fluridone (an ABA biosynthesis inhibitor) decreased the RWC and increased MI in shoots under the alkaline conditions. These data suggest that ABA has a potent priming effect on the adaptive response to alkaline stress in rice and may be useful for improving rice growth in saline-alkaline paddy fields.

  9. Dolomite Dissolution in Alkaline Cementious Media

    NASA Astrophysics Data System (ADS)

    Mittermayr, Florian; Klammer, Dietmar; Köhler, Stephan; Dietzel, Martin

    2010-05-01

    Chemical alteration of concrete has gained much attention over the past years as many cases of deterioration due to sulphate attack, thaumasite formation (TSA) or alkali silica reactions (ASR) have been reported in various constructions (Schmidt et al, 2009). Much less is known about the so called alkali carbonate reaction (ACR). It is believed that dolomite aggregates can react with the alkalis from the cement, dissolve and form calcite and brucite (Katayama, 2004). Due to very low solubility of dolomite in alkaline solutions this reaction seems doubtful. In this study we are trying to gain new insides about the conditions that can lead to the dissolution of dolomite in concrete. Therefore we investigated concrete samples from Austrian tunnels that show partially dissolved dolomite aggregates. Petrological analysis such as microprobe, SEM and Raman spectroscopy as well as a hydrochemical analysis of interstitial solutions and ground water and modelling with PhreeqC (Parkhurst and Appelo, 1999) are carried out. In addition a series of batch experiments is set up. Modelling approaches by PhreeqC show a thermodynamically possibility in the alkaline range when additional Ca2+ in solution causes dolomite to become more and more undersaturated as calcite gets supersaturated. Interacting ground water is enriched in Ca2+and saturated with respect to gypsum as marine evaporites are found in situ rocks. Furthermore it is more likely that Portlandite (Ca(OH)2) plays a more important role than Na and K in the cement. Portlandite acts as an additional Ca2+ source and is much more abundant than the alkalies. Some interstitial solutions are dominated mainly by Na+ and SO42- and reach concentrations up to 30 g/l TDS. It is believed that solutions can even reach thenardite saturation as efflorescences are found on the tunnel walls. In consequence dolomite solubility increases with increasing ionic strength. pH > 11 further accelerate the process of dedolomitization by the removal

  10. The Martian ocean: First acid, then alkaline

    NASA Technical Reports Server (NTRS)

    Schaefer, M. W.

    1992-01-01

    In Mars' distant past, carbon dioxide and water may have been plentiful. Values of total outgassed CO2 from several to about 10 bar are consistent with present knowledge, and this amount of CO2 implies an amount of water outgassed equal to an equivalent depth of 500 to 1000 m. It is quite reasonable, therefore, to envision an early Mars in which there was a body or bodies of liquid water, perhaps in the northern plains, and a dense carbon dioxide atmosphere. Under such conditions, the pH of the water will be low, due to the dissolution of carbon dioxide in the water to form carbonic acid. This acidic water is capable of weathering the available rock quite intensely, particularly because this rock is likely to be heavily fractured (from meteorite bombardment) or even consist of fine particles (such as pyroclastic deposits). As time goes on, however, the carbon dioxide atmosphere will rapidly pass through the ocean to form carbonate deposits. As the density of the atmosphere decreases, so will the flux of carbonic acid into the ocean. Without this input of carbonic acid, the effect of the dissolved weathering products will be to increase the pH of the water. The ocean will then become alkaline. To study this process, I have developed a geochemical cycle model for the atmosphere-hydrosphere-regolith system of Mars. The treatment of geochemical cycles as complex kinetic chemical reactions has been undertaken for terrestrial systems in recent years with much success. This method is capable of elegantly handling the interactions between the simultaneous chemical reactions needed to understand such a system.

  11. Construction and application of recombinant strain for the production of an alkaline protease from Bacillus licheniformis.

    PubMed

    Lin, Songyi; Zhang, Meishuo; Liu, Jingbo; Jones, Gregory S

    2015-03-01

    The alkaline protease gene, Apr, from Bacillus licheniformis 2709 was cloned into an expression vector pET - 28b (+), to yield the recombinant plasmid pET-28b (+) - Apr. The pET-28b (+) - Apr was expressed in a high expression strain E. coli BL21. The amino acid sequence deduced from the DNA sequence analysis revealed a 98% identity to that of Bacillus licheniformis 2709. Sodium salt-Polyacrylamide gel electrophoresis (SDS-PAGE) was used to access the protein expression. SDS-PAGE analysis indicated a protein of Mr of 38.8 kDa. The medium components and condition of incubation were optimized for the growth state of a recombinant strain. The optimal composition of production medium was composed of glucose 8 g/L, peptone 8 g/L and salt solution 10 mL. The samples were incubated on a rotary shaker of 180 r/min at 37°C for 24 h.

  12. Enzymatic dehairing of goat skins using alkaline protease from Bacillus sp. SB12.

    PubMed

    Briki, Selmen; Hamdi, Olfa; Landoulsi, Ahmed

    2016-05-01

    The present paper reports the production, purification and biochemical characterization of an extracellular alkaline protease from Bacillus sp. SB12. The enzyme has been used as an alternative to conventional chemicals treatment for dehairing of goat skins. The protease was optimally active at 37 °C and pH 9. Starch at 2% (w/v) was used as the best carbon source and the addition of yeast extract and peptone at 1% each supported the maximum level of protease production in the presence of 5 mM Ca(2+). Protease purification was performed with ammonium sulphate precipitation at 70% saturated fraction followed by dialysis and gel filtration chromatography using Sephadex G-100. The purified enzyme was homogeneous on non-denaturing PAGE and appeared as a single band with an apparent molecular weight of 41 kDa. This enzyme was moderately thermostable and has a wide pH stability range extending from pH 7 to 11. It showed high tolerance toward surfactants agents and organic solvents while it was completely inhibited by PMSF indicating the serine protease type. Purified protease was used to remove hair from goat skin proving its potential application in leather processing industry. The results revealed that the protease has enhanced the quality and physico-chemical properties of the skins while reducing the pollution.

  13. Chapter A6. Section 6.6. Alkalinity and Acid Neutralizing Capacity

    USGS Publications Warehouse

    Rounds, Stewart A.; Wilde, Franceska D.

    2002-01-01

    Alkalinity (determined on a filtered sample) and Acid Neutralizing Capacity (ANC) (determined on a whole-water sample) are measures of the ability of a water sample to neutralize strong acid. Alkalinity and ANC provide information on the suitability of water for uses such as irrigation, determining the efficiency of wastewater processes, determining the presence of contamination by anthropogenic wastes, and maintaining ecosystem health. In addition, alkalinity is used to gain insights on the chemical evolution of an aqueous system. This section of the National Field Manual (NFM) describes the USGS field protocols for alkalinity/ANC determination using either the inflection-point or Gran function plot methods, including calculation of carbonate species, and provides guidance on equipment selection.

  14. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more that two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  15. Release of bound procyanidins from cranberry pomace by alkaline hydrolysis.

    PubMed

    White, Brittany L; Howard, Luke R; Prior, Ronald L

    2010-07-14

    Procyanidins in plant products are present as extractable or unextractable/bound forms. We optimized alkaline hydrolysis conditions to liberate procyanidins and depolymerize polymers from dried cranberry pomace. Alkaline extracts were neutralized (pH 6-7) and then procyanidins were extracted with ethyl acetate and analyzed by normal phase high performance liquid chromatography. Alkaline hydrolysis resulted in an increase in low molecular weight procyanidins, and the increase was greater at higher temperature, short time combinations. The most procyanidins (DP1-DP3) were extracted at 60 degrees C for 15 min with each concentration of NaOH. When compared to conventional extraction using homogenization with acetone/water/acetic acid (70:29.5:0.5 v/v/v), treatment with NaOH increased procyanidin oligomer extraction by 3.8-14.9-fold, with the greatest increase being DP1 (14.9x) and A-type DP2 (8.4x) procyanidins. Alkaline treatment of the residue remaining after conventional extraction resulted in further procyanidin extraction, indicating that procyanidins are not fully extracted by conventional extraction methods.

  16. Alkaline replenisher evaluation for printed wiring board evaluation

    SciTech Connect

    Tucker, D.R.; Goldammer, S.E.

    1997-04-01

    MacDermid`s Metex{reg_sign} Ultra Etch FL and modifications to the Ultra Etch FL chemistry were evaluated as replacements of a discontinued replenisher, Ultra Etch Aqueous. Ultra Etch FL with additions of water to lower the total alkalinity and ammonium chloride to maintain the chloride level was found to produce acceptable results and, in fact, had a similar chemical composition to Ultra Etch Aqueous.

  17. Predicting Carbonate Ion Transport in Alkaline Anion Exchange Materials

    DTIC Science & Technology

    2012-01-01

    Schematic of the permeation cell experiment used to measure transient CO2 flux across the polymer electrolyte membrane. Experimental result vs. model trend...Microstructure on Charge Transfer, Mass Transfer, and Electrochemical Reactions in Solid Oxide Fuel Cells ; Part 2. Ion and Water Transport in Alkaline Anion...through the use of the Fuel Cell Technologies Test Station such as the relative humidity and flow rate of the feed gases, the cell temperature, and the

  18. Alkaline and alkaline earth metal phosphate halides and phosphors

    DOEpatents

    Lyons, Robert Joseph; Setlur, Anant Achyut; Cleaver, Robert John

    2012-11-13

    Compounds, phosphor materials and apparatus related to nacaphite family of materials are presented. Potassium and rubidium based nacaphite family compounds and phosphors designed by doping divalent rare earth elements in the sites of alkaline earth metals in the nacaphite material families are descried. An apparatus comprising the phosphors based on the nacaphite family materials are presented herein. The compounds presented is of formula A.sub.2B.sub.1-yR.sub.yPO.sub.4X where the elements A, B, R, X and suffix y are defined such that A is potassium, rubidium, or a combination of potassium and rubidium and B is calcium, strontium, barium, or a combination of any of calcium, strontium and barium. X is fluorine, chlorine, or a combination of fluorine and chlorine, R is europium, samarium, ytterbium, or a combination of any of europium, samarium, and ytterbium, and y ranges from 0 to about 0.1.

  19. Long-term alkalinity decrease and acidification of estuaries in northwestern Gulf of Mexico.

    PubMed

    Hu, Xinping; Pollack, Jennifer Beseres; McCutcheon, Melissa R; Montagna, Paul A; Ouyang, Zhangxian

    2015-03-17

    More than four decades of alkalinity and pH data (late 1960s to 2010) from coastal bays along the northwestern Gulf of Mexico were analyzed for temporal changes across a climatic gradient of decreasing rainfall and freshwater inflow, from northeast to southwest. The majority (16 out of 27) of these bays (including coastal waters) showed a long-term reduction in alkalinity at a rate of 3.0-21.6 μM yr(-1). Twenty-two bays exhibited pH decreases at a rate of 0.0014-0.0180 yr(-1). In contrast, a northernmost coastal bay exhibited increases in both alkalinity and pH. Overall, the two rates showed a significant positive correlation, indicating that most of these bays, especially those at lower latitudes, have been experiencing long-term acidification. The observed alkalinity decrease may be caused by reduced riverine alkalinity export, a result of precipitation decline under drought conditions, and freshwater diversion for human consumption, as well as calcification in these bays. A decrease in alkalinity inventory and accompanying acidification may have negative impacts on shellfish production in these waters. In addition, subsequent reduction in alkalinity export from these bays to the adjacent coastal ocean may also decrease the buffer capacity of the latter against future acidification.

  20. Global variability and changes in ocean total alkalinity from Aquarius satellite data

    NASA Astrophysics Data System (ADS)

    Fine, Rana A.; Willey, Debra A.; Millero, Frank J.

    2017-01-01

    This work demonstrates how large-scale Aquarius satellite salinity data have provided an unprecedented opportunity when combined with total alkalinity (TA) equations as a function of salinity and temperature to examine global changes in the CO2 system. Alkalinity is a gauge on the ability of seawater to neutralize acids. TA correlates strongly with salinity. Spatial variability in alkalinity and salinity exceed temporal variability. Northern Hemisphere has more spatial variability in TA and salinity, while less variability in Southern Ocean TA is due to less salinity variability and upwelling of waters enriched in alkalinity. For the first time it is shown that TA in subtropical regions has increased as compared with climatological data; this is reflective of large-scale changes in the global water cycle. Thus, as temperature and salinity increase in subtropical regions, the resultant increase in TA and ocean acidification is reinforcing that from oceanic uptake of atmospheric CO2.

  1. Closed type alkaline storage battery

    SciTech Connect

    Hayama, H.

    1980-06-10

    The alkaline storage battery employs a metallic hat shaped terminal closure which has a piercing needle as well as a puncturable metallic diaphragm positioned below the piercing needle. The needle is fixed by caulking at its peripheral edge portion to a edge of the closure. A comparatively thick and hard metal plate is placed on the inner surface of the diaphragm and is applied to an open portion of a tubular metallic container which has a battery element. A peripheral edge portion of the closure, the diaphragm and the metallic plate are clamped in airtight relationship through a packing between the caulked end portion and an inner annular step portion of the metallic container of the battery. A lead wire extends from one polarity electrode of the battery element and is connected to a central portion of the metallic plate.

  2. Remediation of Former Manufactured Gas Plant Tars Using Alkaline Flushing

    NASA Astrophysics Data System (ADS)

    Hauswirth, S.; Rylander, S.; Birak, P. S.; Miller, C. T.

    2010-12-01

    The remediation of former manufactured gas plant (FMGP) tars in the subsurface is particularly difficult due to the wetting behavior and high viscosities of these dense non-aqueous liquids (DNAPLs). Alkaline flooding is a technique which has proven effective in improving the recovery of crude oils, which share some characteristics with FMGP tars. For this study, we measured the effect of NaOH solutions on interfacial tension and conducted column experiments to investigate the feasibility of applying this technique to FMGP tars. The pendant drop technique was used to measure interfacial tensions for solutions ranging from 0-1% NaOH. Column experiments were conducted by contaminating sands with tars recovered from a FMGP then flushing the columns with NaOH solutions. A final, 70% v/v ethanol cosolvent flush was conducted to investigate the effectiveness of a two-stage remediation approach. The mass removal of tar, as well as 26 individual PAHs, was measured, along with the aqueous phase mass flux of PAHs after each flushing stage. The interfacial tension was reduced from about 20 mN/m with pure water to a minimum of 0.05 mN/m at a concentration of 0.1% NaOH. In the column experiments, alkaline flushing resulted in a 50% reduction of the residual saturation. Aqueous phase PAH concentrations, however, were similar before and after the alkaline flushing stage. The combination of alkaline and cosolvent flushing resulted in an overall reduction of 95% of the total mass of the 16 EPA PAHs. Final aqueous phase concentrations were reduced significantly for lower molecular weight PAHs, but increased slightly for the higher molecular weight compounds, likely due to their increased mole fraction within the remaining tar. Additional work is being conducted to improve the effectiveness of the alkaline flushing through the use of surfactants and polymers.

  3. Energetics of Amino Acid Synthesis in Alkaline Hydrothermal Environments.

    PubMed

    Kitadai, Norio

    2015-12-01

    Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.

  4. Energetics of Amino Acid Synthesis in Alkaline Hydrothermal Environments

    NASA Astrophysics Data System (ADS)

    Kitadai, Norio

    2015-12-01

    Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.

  5. Alkaline nanoparticle coatings improve resin bonding of 10-methacryloyloxydecyldihydrogenphosphate-conditioned zirconia.

    PubMed

    Qian, Mengke; Lu, Zhicen; Chen, Chen; Zhang, Huaiqin; Xie, Haifeng

    Creating an alkaline environment prior to 10-methacryloyloxydecyldihydrogenphosphate (MDP) conditioning improves the resin bonding of zirconia. The present study evaluated the effects of four alkaline coatings with different water solubilities and pH values on resin bonding of MDP-conditioned zirconia. Two alkaline nanoparticle coatings were studied in particular. Thermodynamics calculations were performed to evaluate the strengths of MDP-tetragonal phase zirconia chemical bonds at different pH values. Zirconia surfaces with and without alkaline coatings were characterized by scanning electron microscope (SEM)/energy dispersive spectrometer and Fourier transform infrared spectroscopy; alkaline coatings included NaOH, Ca(OH)2, nano-MgO, and nano-Zr(OH)4. A shear bond strength (SBS) test was performed to evaluate the effects of the four alkaline coatings on bonding; the alkaline coatings were applied to the surfaces prior to conditioning the zirconia with MDP-containing primers. Gibbs free energies of the MDP-tetragonal zirconia crystal model coordination reaction in different pH environments were -583.892 (NaOH), -569.048 [Ca(OH)2], -547.393 (MgO), and -530.279 kJ/mol [Zr(OH)4]. Thermodynamic calculations indicated that the alkaline coatings improved bonding in the following order: NaOH > Ca(OH)2 > MgO > Zr(OH)4. Statistical analysis of SBS tests showed a different result. SBSs were significantly different in groups that had different alkaline coatings, but it was not influenced by different primers. All four alkaline coatings increased SBS compared to control groups. Of the four coatings, nano-Zr(OH)4 and -MgO showed higher SBS. Therefore, preparing nano-Zr(OH)4 or -MgO coatings prior to conditioning with MDP-containing primers may potentially improve resin bonding of zirconia in the clinic.

  6. Alkaline nanoparticle coatings improve resin bonding of 10-methacryloyloxydecyldihydrogenphosphate-conditioned zirconia

    PubMed Central

    Qian, Mengke; Lu, Zhicen; Chen, Chen; Zhang, Huaiqin; Xie, Haifeng

    2016-01-01

    Creating an alkaline environment prior to 10-methacryloyloxydecyldihydrogenphosphate (MDP) conditioning improves the resin bonding of zirconia. The present study evaluated the effects of four alkaline coatings with different water solubilities and pH values on resin bonding of MDP-conditioned zirconia. Two alkaline nanoparticle coatings were studied in particular. Thermodynamics calculations were performed to evaluate the strengths of MDP-tetragonal phase zirconia chemical bonds at different pH values. Zirconia surfaces with and without alkaline coatings were characterized by scanning electron microscope (SEM)/energy dispersive spectrometer and Fourier transform infrared spectroscopy; alkaline coatings included NaOH, Ca(OH)2, nano-MgO, and nano-Zr(OH)4. A shear bond strength (SBS) test was performed to evaluate the effects of the four alkaline coatings on bonding; the alkaline coatings were applied to the surfaces prior to conditioning the zirconia with MDP-containing primers. Gibbs free energies of the MDP-tetragonal zirconia crystal model coordination reaction in different pH environments were −583.892 (NaOH), −569.048 [Ca(OH)2], −547.393 (MgO), and −530.279 kJ/mol [Zr(OH)4]. Thermodynamic calculations indicated that the alkaline coatings improved bonding in the following order: NaOH > Ca(OH)2 > MgO > Zr(OH)4. Statistical analysis of SBS tests showed a different result. SBSs were significantly different in groups that had different alkaline coatings, but it was not influenced by different primers. All four alkaline coatings increased SBS compared to control groups. Of the four coatings, nano-Zr(OH)4 and -MgO showed higher SBS. Therefore, preparing nano-Zr(OH)4 or -MgO coatings prior to conditioning with MDP-containing primers may potentially improve resin bonding of zirconia in the clinic. PMID:27785013

  7. Aeromonas presence in drinking water from collective reservoirs and wells in peri-urban area in Brazil.

    PubMed

    Pepe Razzolini, Maria Tereza; Risso Günther, Wanda Maria; Martone-Rocha, Solange; Duarte de Luca, Heloísa; Alves Cardoso, Maria Regina

    2010-07-01

    Aeromonas genus is considered an emerging pathogen and its presence in drinking water supplies is a reason to public health concern. This study investigated the occurrence of Aeromonas in samples from collective reservoirs and wells used as drinking water sources in a peri-urban area. A total of 35 water samples were collected from collective reservoirs and 32 from wells bimonthly, from September 2007 to September 2008. Aeromonas spp determination was carried out using a Multiple-Tube Technique. Samples were inoculated into alkaline peptone water and the superficial film formed was transferred to blood agar plates amended with ampicillin. Typical Aeromonas colonies were submitted to a biochemical screening and then to biochemical tests for species differentiation. Aeromonas was detected in 13 (19%) of the 69 samples examined (6 from collective reservoirs and 7 from wells). Concentrations of Aeromonas in collective reservoirs ranged from <0.3 to 1.2 x10(2)MPN/100mL and, in wells, from <0.3 to 2.4 x10(2)MPN/100mL. The most frequent specie in the collective reservoir samples was Aeromonas spp (68%), followed by A. encheleia (14%) and A. allosaccharophila (8%) and A. hydrophila (8%). Aeromonas spp (87%) was the most frequent specie isolated from well samples, followed by A. allosacchariphila (8%), A. encheleia (2%) and A. jandaei (5%). These data show the presence and diversity of Aeromonas genus in the samples analyzed and highlight that its presence in drinking water poses a significant public health concern.

  8. Evolution of alkaline phosphatases in primates.

    PubMed Central

    Goldstein, D J; Rogers, C; Harris, H

    1982-01-01

    Alkaline phosphatase [orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] in placenta, intestine, liver, kidney, bone, and lung from a variety of primate species has been characterized by quantitative inhibition, thermostability, and immunological studies. Characteristic human placental-type alkaline phosphatase occurs in placentas of great apes (chimpanzee and orangutan) but not in placentas of other primates, including gibbon. It is also present in trace amounts in human lung but not in lung or other tissues of various Old and New World monkeys. However, a distinctive alkaline phosphatase resembling it occurs in substantial amounts in lungs from Old World monkeys but not New World monkeys. It appears that duplication of alkaline phosphatase genes and mutations of genetic elements controlling their tissue expression have occurred relatively recently in mammalian evolution. Images PMID:6950431

  9. Alkaline pH sensor molecules.

    PubMed

    Murayama, Takashi; Maruyama, Ichiro N

    2015-11-01

    Animals can survive only within a narrow pH range. This requires continual monitoring of environmental and body-fluid pH. Although a variety of acidic pH sensor molecules have been reported, alkaline pH sensor function is not well understood. This Review describes neuronal alkaline pH sensors, grouped according to whether they monitor extracellular or intracellular alkaline pH. Extracellular sensors include the receptor-type guanylyl cyclase, the insulin receptor-related receptor, ligand-gated Cl- channels, connexin hemichannels, two-pore-domain K+ channels, and transient receptor potential (TRP) channels. Intracellular sensors include TRP channels and gap junction channels. Identification of molecular mechanisms underlying alkaline pH sensing is crucial for understanding how animals respond to environmental alkaline pH and how body-fluid pH is maintained within a narrow range.

  10. Alkaline static feed electrolyzer based oxygen generation system

    NASA Technical Reports Server (NTRS)

    Noble, L. D.; Kovach, A. J.; Fortunato, F. A.; Schubert, F. H.; Grigger, D. J.

    1988-01-01

    In preparation for the future deployment of the Space Station, an R and D program was established to demonstrate integrated operation of an alkaline Water Electrolysis System and a fuel cell as an energy storage device. The program's scope was revised when the Space Station Control Board changed the energy storage baseline for the Space Station. The new scope was aimed at the development of an alkaline Static Feed Electrolyzer for use in an Environmental Control/Life Support System as an oxygen generation system. As a result, the program was divided into two phases. The phase 1 effort was directed at the development of the Static Feed Electrolyzer for application in a Regenerative Fuel Cell System. During this phase, the program emphasized incorporation of the Regenerative Fuel Cell System design requirements into the Static Feed Electrolyzer electrochemical module design and the mechanical components design. The mechanical components included a Pressure Control Assembly, a Water Supply Assembly and a Thermal Control Assembly. These designs were completed through manufacturing drawing during Phase 1. The Phase 2 effort was directed at advancing the Alkaline Static Feed Electrolyzer database for an oxygen generation system. This development was aimed at extending the Static Feed Electrolyzer database in areas which may be encountered from initial fabrication through transportation, storage, launch and eventual Space Station startup. During this Phase, the Program emphasized three major areas: materials evaluation, electrochemical module scaling and performance repeatability and Static Feed Electrolyzer operational definition and characterization.

  11. Cementitious porous pavement in stormwater quality control: pH and alkalinity elevation.

    PubMed

    Kuang, Xuheng; Sansalone, John

    2011-01-01

    A certain level of alkalinity acts as a buffer and maintains the pH value in a stable range in water bodies. With rapid urban development, more and more acidic pollutants flow to watersheds with runoff and drop alkalinity to a very low level and ultimately degrade the water environment. Cementitious porous pavement is an effective tool for stormwater acidic neutralization. When stormwater infiltrates cement porous pavement (CPP) materials, alkalinity and pH will be elevated due to the basic characteristics of cement concrete. The elevated alkalinity will neutralize acids in water bodies and maintain the pH in a stable level as a buffer. It is expected that CPP materials still have a certain capability of alkalinity elevation after years of service, which is important for CPP as an effective tool for stormwater management. However, few previous studies have reported on how CPP structures would elevate runoff alkalinity and pH after being exposed to rainfall-runoff for years. In this study, three groups of CPP specimens, all exposed to rainfall-runoff for 3 years, were used to test the pH and alkalinity elevation properties. It was found that runoff pH values were elevated from 7.4 to the range of 7.8-8.6 after infiltrating through the uncoated specimens, and from 7.4 to 8.5-10.7 after infiltrating through aluminum-coated specimens. Runoff alkalinity elevation efficiencies are 11.5-14.5% for uncoated specimens and 42.2% for coated specimens. The study shows that CPP is an effective passive unit operation for stormwater acid neutralization in our built environment.

  12. Catalytic Diversity in Alkaline Hydrothermal Vent Systems on Ocean Worlds

    NASA Astrophysics Data System (ADS)

    Cameron, Ryan D.; Barge, Laura; Chin, Keith B.; Doloboff, Ivria J.; Flores, Erika; Hammer, Arden C.; Sobron, Pablo; Russell, Michael J.; Kanik, Isik

    2016-10-01

    Hydrothermal systems formed by serpentinization can create moderate-temperature, alkaline systems and it is possible that this type of vent could exist on icy worlds such as Europa which have water-rock interfaces. It has been proposed that some prebiotic chemistry responsible for the emergence of life on Earth and possibly other wet and icy worlds could occur as a result ofredox potential and pH gradients in submarine alkaline hydrothermal vents (Russell et al., 2014). Hydrothermal chimneys formed in laboratory simulations of alkaline vents under early Earth conditions have precipitate membranes that contain minerals such as iron sulfides, which are hypothesized to catalyze reduction of CO2 (Yamaguchi et al. 2014, Roldan et al. 2014) leading to further organic synthesis. This CO2 reduction process may be affected by other trace components in the chimney, e.g. nickel or organic molecules. We have conducted experiments to investigate catalytic properties of iron and iron-nickel sulfides containing organic dopants in slightly acidic ocean simulants relevant to early Earth or possibly ocean worlds. We find that the electrochemical properties of the chimney as well as the morphology/chemistry of the precipitate are affected by the concentration and type of organics present. These results imply that synthesis of organics in water-rock systems on ocean worlds may lead to hydrothermal precipitates which can incorporate these organic into the mineral matrix and may affect the role of gradients in alkaline vent systems.Therefore, further understanding on the electroactive roles of various organic species within hydrothermal chimneys will have important implications for habitability as well as prebiotic chemistry. This work is funded by NASA Astrobiology Institute JPL Icy Worlds Team and a NAI Director's Discretionary Fund award.Yamaguchi A. et al. (2014) Electrochimica Acta, 141, 311-318.Russell, M. J. et al. (2014), Astrobiology, 14, 308-43.Roldan, A. (2014) Chem. Comm. 51

  13. Metal bioavailability and toxicity to fish in low-alkalinity lakes - a critical-review

    USGS Publications Warehouse

    Spry, D.J.; Wiener, J.G.

    1991-01-01

    Fish in low-alkalinity lakes having ph of 6.0-6.5 Or less often have higher body or tissue burdens of mercury, cadmium, and lead than do fish in nearby lakes with higher ph. The greater bioaccumulation of these metals in such waters seems to result partly from the greater aqueous abundances of biologically available forms (ch3hg+, cd2+, and pb2+) at low ph. In addition, the low concentrations of aqueous calcium in low-alkalinity lakes increase the permeability of biological membranes to these metals, which in fish may cause greater uptake from both water and food. Fish exposed to aqueous inorganic aluminum in the laboratory and field accumulate the metal in and on the epithelial cells of the gills; however, there is little accumulation of aluminum in the blood or internal organs. In low-ph water, both sublethal and lethal toxicity of aluminum has been clearly demonstrated in both laboratory and field studies at environmental concentrations. In contrast, recently measured aqueous concentrations of total mercury, methylmercury, cadmium, and lead in low-alkalinity lakes are much lower than the aqueous concentrations known to cause acute or chronic toxicity in fish, although the vast majority of toxicological research has involved waters with much higher ionic strength than that in low-alkalinity lakes. Additional work with fish is needed to better assess (1) the toxicity of aqueous metals in low-alkalinity waters, and (2) the toxicological significance of dietary methylmercury and cadmium.

  14. Process for extracting technetium from alkaline solutions

    DOEpatents

    Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.

    1995-01-01

    A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate, the at least one alkali metal nitrate having a concentration of from about 0.1 to 6 molar. The solution is contacted with a solvent consisting of a crown ether in a diluent for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution. The solvent containing the technetium values is separated from the aqueous alkaline solution and the technetium values are stripped from the solvent.

  15. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  16. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2003-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  17. Properties of whey protein isolates extruded under acidic and alkaline conditions.

    PubMed

    Onwulata, C I; Isobe, S; Tomasula, P M; Cooke, P H

    2006-01-01

    Whey proteins have wide acceptance and use in many products due to their beneficial nutritional properties. To further increase the amount of whey protein isolates (WPI) that may be added to products such as extruded snacks and meats, texturization of WPI is necessary. Texturization changes the folding of globular proteins to improve interaction with other ingredients and create new functional ingredients. In this study, WPI pastes (60% solids) were extruded in a twin-screw extruder at 100 degrees C with 4 pH-adjusted water streams: acidic (pH 2.0 +/- 0.2) and alkaline (pH 12.4 +/- 0.4) streams from 2 N HCl and 2 N NaOH, respectively, and acidic (pH 2.5 +/- 0.2) and alkaline (pH 11.5 +/- 0.4) electrolyzed water streams; these were compared with WPI extruded with deionized water. The effects of water acidity on WPI solubility at pH 7, color, microstructure, Rapid Visco Analyzer pasting properties, and physical structure were determined. Alkaline conditions increased insolubility caused yellowing and increased pasting properties significantly. Acidic conditions increased solubility and decreased WPI pasting properties. Subtle structural changes occurred under acidic conditions, but were more pronounced under alkaline conditions. Overall, alkaline conditions increased denaturation in the extruded WPI resulting in stringy texturized WPI products, which could be used in meat applications.

  18. Alkaline tolerant dextranase from streptomyces anulatus

    DOEpatents

    Decker, Stephen R.; Adney, William S.; Vinzant, Todd B.; Himmel, Michael E.

    2003-01-01

    A process for production of an alkaline tolerant dextranase enzyme comprises culturing a dextran-producing microorganism Streptomyces anulatus having accession no. ATCC PTA-3866 to produce an alkaline tolerant dextranase, Dex 1 wherein the protein in said enzyme is characterized by a MW of 63.3 kDa and Dex 2 wherein its protein is characterized by a MW of 81.8 kDa.

  19. Technetium recovery from high alkaline solution

    DOEpatents

    Nash, Charles A.

    2016-07-12

    Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

  20. The Origin of Life in Alkaline Hydrothermal Vents.

    PubMed

    Sojo, Victor; Herschy, Barry; Whicher, Alexandra; Camprubí, Eloi; Lane, Nick

    2016-02-01

    Over the last 70 years, prebiotic chemists have been very successful in synthesizing the molecules of life, from amino acids to nucleotides. Yet there is strikingly little resemblance between much of this chemistry and the metabolic pathways of cells, in terms of substrates, catalysts, and synthetic pathways. In contrast, alkaline hydrothermal vents offer conditions similar to those harnessed by modern autotrophs, but there has been limited experimental evidence that such conditions could drive prebiotic chemistry. In the Hadean, in the absence of oxygen, alkaline vents are proposed to have acted as electrochemical flow reactors, in which alkaline fluids saturated in H2 mixed with relatively acidic ocean waters rich in CO2, through a labyrinth of interconnected micropores with thin inorganic walls containing catalytic Fe(Ni)S minerals. The difference in pH across these thin barriers produced natural proton gradients with equivalent magnitude and polarity to the proton-motive force required for carbon fixation in extant bacteria and archaea. How such gradients could have powered carbon reduction or energy flux before the advent of organic protocells with genes and proteins is unknown. Work over the last decade suggests several possible hypotheses that are currently being tested in laboratory experiments, field observations, and phylogenetic reconstructions of ancestral metabolism. We analyze the perplexing differences in carbon and energy metabolism in methanogenic archaea and acetogenic bacteria to propose a possible ancestral mechanism of CO2 reduction in alkaline hydrothermal vents. Based on this mechanism, we show that the evolution of active ion pumping could have driven the deep divergence of bacteria and archaea.

  1. Vehicle Integrated Photovoltaics for Compression Ignition Vehicles: An Experimental Investigation of Solar Alkaline Water Electrolysis for Improving Diesel Combustion and a Solar Charging System for Reducing Auxiliary Engine Loads

    NASA Astrophysics Data System (ADS)

    Negroni, Garry Inocentes

    Vehicle-integrated photovoltaic electricity can be applied towards aspiration of hydrogen-oxygen-steam gas produced through alkaline electrolysis and reductions in auxiliary alternator load for reducing hydrocarbon emissions in low nitrogen oxide indirect-injection compression-ignition engines. Aspiration of 0.516 ± 0.007 liters-per-minute of gas produced through alkaline electrolysis of potassium-hydroxide 2wt.% improves full-load performance; however, part-load performance decreases due to auto-ignition of aspirated gas prior to top-dead center. Alternator load reductions offer improved part-load and full-load performance with practical limitations resulting from accessory electrical loads. In an additive approach, solar electrolysis can electrochemically convert solar photovoltaic electricity into a gas comprised of stoichiometric hydrogen and oxygen gas. Aspiration of this hydrogen-oxygen gas enhances combustion properties decreasing emissions and increased combustion efficiency in light-duty diesel vehicles. The 316L stainless steel (SS) electrolyser plates are arranged with two anodes and three cathodes space with four bipolar plates delineating four stacks in parallel with five cells per stack. The electrolyser was tested using potassium hydroxide 2 wt.% and hydronium 3wt.% at measured voltage and current inputs. The flow rate output from the reservoir cell was measured in parallel with the V and I inputs producing a regression model correlating current input to flow rate. KOH 2 wt.% produced 0.005 LPM/W, while H9O44 3 wt.% produced less at 0.00126 LPM/W. In a subtractive approach, solar energy can be used to charge a larger energy storage device, as is with plug-in electric vehicles, in order to alleviate the engine of the mechanical load placed upon it by the vehicles electrical accessories through the alternator. Solar electrolysis can improve part-load emissions and full-load performance. The average solar-to-battery efficiency based on the OEM rated

  2. [Alkaline phosphatase in Amoeba proteus].

    PubMed

    Sopina, V A

    2005-01-01

    In free-living Amoeba proteus (strain B), 3 phosphatase were found after disc-electrophoresis of 10 microg of protein in PAGE and using 1-naphthyl phosphate as a substrate a pH 9.0. These phosphatases differed in their electrophoretic mobilities - "slow" (1-3 bands), "middle" (one band) and "fast" (one band). In addition to 1-naphthyl phosphate, "slow" phosphatases were able to hydrolyse 2-naphthyl phosphate and p-nitrophenyl phosphate. They were slightly activated by Mg2+, completely inhibited by 3 chelators (EDTA, EGTA and 1,10-phenanthroline), L-cysteine, sodium dodecyl sulfate and Fe2+, Zn2+ and Mn2+ (50 mM), considerably inactivated by orthovanadate, molybdate, phosphatase inhibitor cocktail 1, p-nitrophenyl phosphate, Na2HPO4, DL-dithiothreitol and urea and partly inhibited by H2O2, DL-phenylalanine, 2-mercaptoethanol, phosphatase inhibitor cocktail 2 and Ca2+. Imidazole, L-(+)-tartrate, okadaic acid, NaF and sulfhydryl reagents -p-(hydroxy-mercuri)benzoate and N-ethylmaleimide - had no influence on the activity of "slow" phosphatases. "Middle" and "fast" phosphatases, in contrast to "slow" ones, were not inactivated by 3 chelators. The "middle" phosphatase differed from the "fast" one by smaller resistance to urea, Ca2+, Mn2+, phosphates and H2O2 and greater resistance to dithiothreitol and L-(+)-tartrate. In addition, the "fast" phosphatase was inhibited by L-cysteine but the "middle" one was activated by it. Of 5 tested ions (Mg2+, Cu2+, Mn2+, Ca2+ and Zn2+), only Zn2+ reactivated "slow" phosphatases after their inactivation by EDTA treatment. The reactivation of apoenzyme was only partial (about 35 %). Thus, among phosphatases found in amoebae at pH 9.0, only "slow" ones are Zn-metalloenzymes and may be considered as alkaline phosphatases (EC 3.1.3.1). It still remains uncertain, to which particular phosphatase class "middle" and "fast" phosphatases (pH 9.0) may belong.

  3. Thermostable, alkaline and detergent-tolerant lipase from a newly isolated thermophilic Bacillus stearothermophilus.

    PubMed

    Ben Bacha, Abir; Moubayed, Nadine M S; Abid, Islam

    2015-04-01

    Lipases are the enzymes of choice for laundry detergent industries, owing to their triglyceride removing ability from the soiled fabric, which eventually reduces the usage of phosphate-based chemical cleansers in the detergent formulation. In this study, a novel thermo-alkaline lipase-producing strain identified as Bacillus stearothermophilus was isolated from the soil samples of olive oil mill. Enhanced lipase production was observed at 55 degrees C, pH 11 and after 48 h of incubation. Among the substrates tested, xylose (a carbon source), peptone (a nitrogen source) and olive oil at a concentration of 1% were suitable substrates for enhancing lipase production. MgSO4 and Tween-80 were suitable substrates for maximizing lipase production. The enzyme was purified to homogeneity by a single CM-Sephadex column chromatography and revealed molecular mass of 67 kDa. The enzyme (BL1) was active over a wide range of pH from 9.0 to 13.0, with an optimum at pH 11.0, exhibited maximal activity at 55 degreesC and retained more than 70% of its activity after incubation at 70 degrees C or pH 13 for 0.5 h or 24 h, respectively. The enzyme hydrolyzed both short and long-chain triacylglycerols at comparable rates. BL1 was studied in a preliminary evaluation for use in detergent formulation solutions. This novel lipase showed extreme stability towards non-ionic and anionic surfactants after pre-incubation for 1 h at 40 degrees C, and good stability towards oxidizing agents. Additionally, the enzyme showed excellent stability and compatibility with various commercial detergents, suggesting its potential as an additive in detergent formulations.

  4. Coupling alkaline pre-extraction with alkaline-oxidative post-treatment of corn stover to enhance enzymatic hydrolysis and fermentability

    PubMed Central

    2014-01-01

    -stage pretreatment process is well suited for converting lignocellulose to fermentable sugars and biofuels, such as ethanol. This approach achieved high enzymatic sugars yields from pretreated corn stover using substantially lower oxidant loadings than have been reported previously in the literature. This pretreatment approach allows for many possible process configurations involving novel alkali recovery approaches and novel uses of alkaline pre-extraction liquors. Further work is required to identify the most economical configuration, including process designs using techno-economic analysis and investigating processing strategies that economize water use. PMID:24693882

  5. Water

    MedlinePlus

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  6. Experimental data developed to support the selection of a treatment process for West Valley alkaline supernatant

    SciTech Connect

    Bray, L.A.; Holton, L.K.; Myers, T.R.; Richardson, G.M.; Wise, B.M.

    1984-01-01

    At the request of West Valley Nuclear Services Co., Inc., the Pacific Northwest Laboratory (PNL) has studied alternative treatment processes for the alkaline PUREX waste presently being stored in Tank 8D2 at West Valley, New York. Five tasks were completed during FY 1983: (1) simulation and characterization of the alkaline supernatant and sludge from the tank. The radiochemical and chemical distributions between the aqueous and solid phase were determined, and the efficiency of washing sludge with water to remove ions such as Na/sup +/ and SO/sub 4//sup 2 -/ was investigated; (2) evaluation of a sodium tetraphenylboron (Na-TPB) precipitation process to recover cesium (Cs) and a sodium titanate (Na-TiA) sorption process to recover strontium (Sr) and plutonium (Pu) from the West Valley Alkaline supernatant. These processes were previously developed and tested at the US Department of Energy's Savannah River Plant; (3) evaluation of an organic cation-exchange resin (Duolite CS-100) to recover Cs and Pu from the alkaline supernatant followed by an organic macroreticular cation exchange resin (Amberlite IRC-718) to recover Sr; (4) evaluation of an inorganic ion exchanger (Linde Ionsiv IE-95) to recover Cs, Sr, and Pu from the alkaline supernatant; and (5) evaluation of Dowex-1,X8 organic anion exchange resin to recover technetium (Tc) from alkaline supernatant. The findings of these tasks are reported. 21 references, 36 figures, 34 tables.

  7. Solid / solution interaction: The effect of carbonate alkalinity on adsorbed thorium

    NASA Astrophysics Data System (ADS)

    LaFlamme, Brian D.; Murray, James W.

    1987-02-01

    Elevated activities of dissolved Th have been found in Soap Lake, an alkaline lake in Eastern Washington. Dissolved 232Th ranges from less than 0.001 to 4.9 dpm/L compared to about 1.3 × 10 -5 dpm/ L in sea water. The enhanced activity in the lake coincides with an increase in carbonate alkalinity. Experiments were conducted to evaluate the effect of pH, ionic strength and carbonate alkalinity on Th adsorption on goethite. Thorium (10 -13 M total) in the presence of 5.22 mg/L α-FeOOH and 0.1 M NaNO 3 has an adsorption edge from pH 2-5. At pH 9.0 ± 0.6 the percent Th absorbed on the solid began to decrease from 100% at 100 meq/L carbonate alkalinity and exhibited no adsorption above 300 meq/L. The experimental data were modeled to obtain the intrinsic adsorption equilibrium constants for Th hydrolysis species. These adsorption constants were incorporated in the model to interpret the observed effect of carbonate alkalinity on Th adsorption. There are two main effects of the alkalinity. To a significant degree the decrease in Th adsorption is due to competition of HCO -3 and CO 2-3 ions for surface sites. Dissolved Th carbonate complexes also contribute to the increase of Th in solution.

  8. Re-epithelialization of the Buccal Mucosa after Alkaline Chemical Injury.

    PubMed

    Takaichi, Saneyuki; Muramatsu, Takashi; Lee, Jong-Min; Jung, Han-Sung; Shinozaki, Naoshi; Katakura, Akira; Yamane, Gen-Yuki

    2014-01-01

    Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water and bicarbonate toothpaste. However, the effects of an alkaline pH on the oral mucosa had not been elucidated. The purpose of this study was to investigate how basal keratinocytes are actively involved in re-epithelialization after alkaline chemical injury. We generated epithelial defects in the oral mucosa of mice by applying an alkaline chemical, and the localization of cytokeratin 13, cytokeratin 14, PCNA and p63 was investigated during the re-epithelialization process. PCNA- and p63-positive staining was seen in basal cells covering the wound surface at 1 day after the chemical injury. Cytokeratin 14-positive and PCNA-negative basal keratinocytes were localized in a few layers of the wound epithelium during epithelial outgrowth. Cytokeratin 14-positive and PCNA-positive basal keratinocytes, indicating proliferation, were localized over the entire layer of the epithelium at the wound margin. These results imply that basal keratinocytes at the wound margin migrate to the wound surface, provoke differentiation and keratinization during epithelial outgrowth and that epithelial cells are supplied from the wound margin to the epithelial outgrowth after alkaline chemical injury.

  9. Clonal Integration Enhances the Performance of a Clonal Plant Species under Soil Alkalinity Stress

    PubMed Central

    Sun, Juanjuan; Chen, Jishan; Zhang, Yingjun

    2015-01-01

    Clonal plants have been shown to successfully survive in stressful environments, including salinity stress, drought and depleted nutrients through clonal integration between original and subsequent ramets. However, relatively little is known about whether clonal integration can enhance the performance of clonal plants under alkalinity stress. We investigated the effect of clonal integration on the performance of a typical rhizomatous clonal plant, Leymus chinensis, using a factorial experimental design with four levels of alkalinity and two levels of rhizome connection treatments, connected (allowing integration) and severed (preventing integration). Clonal integration was estimated by comparing physiological and biomass features between the rhizome-connected and rhizome-severed treatments. We found that rhizome-connected treatment increased the biomass, height and leaf water potential of subsequent ramets at highly alkalinity treatments but did not affect them at low alkalinity treatments. However, rhizome-connected treatment decreased the root biomass of subsequent ramets and did not influence the photosynthetic rates of subsequent ramets. The biomass of original ramets was reduced by rhizome-connected treatment at the highest alkalinity level. These results suggest that clonal integration can increase the performance of clonal plants under alkalinity stress. Rhizome-connected plants showed dramatically increased survival of buds with negative effects on root weight, indicating that clonal integration influenced the resource allocation pattern of clonal plants. A cost-benefit analysis based on biomass measures showed that original and subsequent ramets significantly benefited from clonal integration in highly alkalinity stress, indicating that clonal integration is an important adaptive strategy by which clonal plants could survive in local alkalinity soil. PMID:25790352

  10. Clonal integration enhances the performance of a clonal plant species under soil alkalinity stress.

    PubMed

    Zhang, Wenjun; Yang, Gaowen; Sun, Juanjuan; Chen, Jishan; Zhang, Yingjun

    2015-01-01

    Clonal plants have been shown to successfully survive in stressful environments, including salinity stress, drought and depleted nutrients through clonal integration between original and subsequent ramets. However, relatively little is known about whether clonal integration can enhance the performance of clonal plants under alkalinity stress. We investigated the effect of clonal integration on the performance of a typical rhizomatous clonal plant, Leymus chinensis, using a factorial experimental design with four levels of alkalinity and two levels of rhizome connection treatments, connected (allowing integration) and severed (preventing integration). Clonal integration was estimated by comparing physiological and biomass features between the rhizome-connected and rhizome-severed treatments. We found that rhizome-connected treatment increased the biomass, height and leaf water potential of subsequent ramets at highly alkalinity treatments but did not affect them at low alkalinity treatments. However, rhizome-connected treatment decreased the root biomass of subsequent ramets and did not influence the photosynthetic rates of subsequent ramets. The biomass of original ramets was reduced by rhizome-connected treatment at the highest alkalinity level. These results suggest that clonal integration can increase the performance of clonal plants under alkalinity stress. Rhizome-connected plants showed dramatically increased survival of buds with negative effects on root weight, indicating that clonal integration influenced the resource allocation pattern of clonal plants. A cost-benefit analysis based on biomass measures showed that original and subsequent ramets significantly benefited from clonal integration in highly alkalinity stress, indicating that clonal integration is an important adaptive strategy by which clonal plants could survive in local alkalinity soil.

  11. Application of duplex-PCR in rapid and reliable detection of toxigenic Vibrio cholerae in water samples in Thailand.

    PubMed

    Chomvarin, Chariya; Namwat, Wises; Wongwajana, Suwin; Alam, Munirul; Thaew-Nonngiew, Kesorn; Sinchaturus, Anuchit; Engchanil, Chulapan

    2007-08-01

    Toxigenic Vibrio cholerae, the cause of cholera, is a native flora of the aquatic environment which is transmitted through drinking water and still remains the leading cause of morbidity and mortality in many developing countries including Thailand. The culture method (CM), which is routinely used for assessing water quality, has not proven as efficient as molecular methods because the notorious pathogen survives in water mostly in a non-culturable state. We employed duplex-polymerase chain reaction (duplex-PCR) for detection of tcpA and ctxA genes in toxigenic V. cholerae, and compared PCR detection with CM in various waters of Khon Kaen Municipality, Thailand. We also evaluated the effect of different pre-PCR conditions on the results of ctxA and tcpA detection including: 1) water filtered and enriched in alkaline peptone water (APW) for 3 h before PCR, 2) water filtered without enrichment before PCR, and 3) use of only enrichment in APW for 6 h before PCR. Of the 96 water samples (taken from waste-water, potable and waste-water from patients' houses, and from rivers) tested, 48 (50%) were positive for ctxA and tcpA by duplex-PCR, whereas only 29 (30%) were positive for V. cholerae by CM. Of the 29 V. cholerae isolated by CM, 2 (7%) were toxigenic V. cholerae belonging to serovar O1, while the rests were non-O1/ non-O139. Results revealed, therefore, that ctxA and tcpA-targeted duplex PCR is more sensitive than CM for detection of toxigenic V. cholerae from water samples because CM detected much less toxigenic V. cholerae than the non-toxigenic V. cholerae. Template DNA as low as 100 fg or 23 cells of V. cholerae in the water sample was detected in duplex PCR. Pre-PCR filtration followed by enrichment for 3 h significantly increase in the efficiency of duplex-PCR detection of toxigenic V. cholerae.

  12. Evaluation of high solids alkaline pretreatment of rice straw.

    PubMed

    Cheng, Yu-Shen; Zheng, Yi; Yu, Chao Wei; Dooley, Todd M; Jenkins, Bryan M; VanderGheynst, Jean S

    2010-11-01

    Fresh-harvested, air-dried rice straw was pretreated at a water content of 5 g H(2)O/g straw using sodium hydroxide (NaOH) and compared to pretreatment at 10 g H(2)O/g straw by hydrated lime (Ca(OH)(2)). Full factorial experiments including parallel wash-only treatments were completed with both sources of alkali. The experiments were designed to measure the effects of alkaline loading and pretreatment time on delignification and sugar yield upon enzymatic hydrolysis. Reaction temperature was held constant at 95 degrees C for lime pretreatment and 55 degrees C for NaOH pretreatment. The range of delignification was 13.1% to 27.0% for lime pretreatments and was 8.6% to 23.1% for NaOH pretreatments. Both alkaline loading and reaction time had significant positive effects (p < 0.001) on delignification under the design conditions, but only alkaline loading had a significant positive effect on enzymatic hydrolysis. Treatment at higher temperature also improved delignification; delignification with water alone ranged from 9.9% to 14.5% for pretreatment at 95 degrees C, but there was little effect observed at 55 degrees C. Post-pretreatment washing of biomass was not necessary for subsequent enzymatic hydrolysis. Maximum glucose yields were 176.3 mg/g dried biomass (48.5% conversion efficiency of total glucose) in lime-pretreated and unwashed biomass and were 142.3 mg/g dried biomass (39.2% conversion efficiency of total glucose) in NaOH-pretreated and unwashed biomass.

  13. Simulation of future stream alkalinity under changing deposition and climate scenarios.

    PubMed

    Welsch, Daniel L; Cosby, B Jack; Hornberger, George M

    2006-08-31

    Models of soil and stream water acidification have typically been applied under scenarios of changing acidic deposition, however, climate change is usually ignored. Soil air CO2 concentrations have potential to increase as climate warms and becomes wetter, thus affecting soil and stream water chemistry by initially increasing stream alkalinity at the expense of reducing base saturation levels on soil exchange sites. We simulate this change by applying a series of physically based coupled models capable of predicting soil air CO2 and stream water chemistry. We predict daily stream water alkalinity for a small catchment in the Virginia Blue Ridge for 60 years into the future given stochastically generated daily climate values. This is done for nine different combinations of climate and deposition. The scenarios for both climate and deposition include a static scenario, a scenario of gradual change, and a scenario of abrupt change. We find that stream water alkalinity continues to decline for all scenarios (average decrease of 14.4 microeq L-1) except where climate is gradually warming and becoming more moist (average increase of 13 microeq L-1). In all other scenarios, base cation removal from catchment soils is responsible for limited alkalinity increase resulting from climate change. This has implications given the extent that acidification models are used to establish policy and legislation concerning deposition and emissions.

  14. Acidic and alkaline bottom ash and composted manure blends as a soil amendment.

    PubMed

    Mukhtar, S; Sadaka, S S; Kenimer, A L; Rahman, S; Mathis, J G

    2008-09-01

    Potential water quality impacts associated with using bottom ash (BA) and composted dairy manure (CM) as a soil amendment were evaluated in this study. Two column studies were conducted to evaluate three blends of acidic BA and CM (BA:CM, v/v) namely, B1ac (95:5), B2ac (90:10), and B3ac (80:20) and three blends of alkaline BA and CM (BA:CM, v/v), namely, B1al (95:5), B2al (90:10), and B3al (80:20) under constant head water table conditions. Samples from standing water (top) and leachate (bottom) were collected at weekly intervals until day 49 to evaluate the effects of different blend ratios and elapsed time on standing water and leachate chemical and physical properties. A higher CM content in both acidic and alkaline blends resulted in higher leachate concentrations for solids and nutrients tested in this study. Alkaline blends had higher standing water and leachate nutrients concentration compared to acidic blends. After day 28, standing water total dissolved solids (TDS) concentrations for all acidic blends was below the USEPA drinking water standard however, TDS value for alkaline blend was always below the standard. Similar trends were also observed for NO3-N and phosphorus (P) concentrations for both blends. Based on these findings, it was concluded that acidic and alkaline blends B1ac, B1al, B2ac and B2al may be considered as a soil amendment material.

  15. Intermediate range order in alkaline borate glasses

    NASA Astrophysics Data System (ADS)

    Crupi, C.; Carini, G.; Ruello, G.; D'Angelo, G.

    2016-03-01

    We describe the neutron diffraction patterns of a series of alkaline borate glasses at different metal oxide content. Strong differences are observed in the intermediate range order as a function of the specific alkaline ion and of its concentration. On these results, we propose that the first sharp diffraction peak arises from correlations of atoms of voids and show that the compositional variation of this peak intensity in alkaline borate glasses is due to changes in the distribution of void sizes within the three-dimensional network. We argue that our interpretation in terms of interstitial (empty and/or filled) voids, having different sizes, provides a general explanation for all anomalous behaviours revealed for the first sharp diffraction peak.

  16. Oxidation of ammonia and methane in an alkaline, saline lake

    USGS Publications Warehouse

    Joye, S.B.; Connell, T.L.; Miller, L.G.; Oremland, R.S.; Jellison, R.S.

    1999-01-01

    The oxidation of ammonia (NH3) and methane (CH4) was investigated in an alkaline saline lake, Mono Lake, California (U.S.A.). Ammonia oxidation was examined in April and July 1995 by comparing dark 14CO2 fixation rates in the presence or absence of methyl fluoride (MeF), an inhibitor of NH3 oxidation. Ammonia oxidizer-mediated dark 14CO2 fixation rates were similar in surface (5-7 m) and oxycline (11-15 m) waters, ranging between 70-340 and 89-186 nM d-1, respectively, or 1-7% of primary production by phytoplankton. Ammonia oxidation rates ranged between 580-2,830 nM d-1 in surface waters and 732-1,548 nM d-1 in oxycline waters. Methane oxidation was examined using a 14CH4 tracer technique in July 1994, April 1995, and July 1995. Methane oxidation rates were consistently higher in July, and rates in oxycline and anaerobic bottom waters (0.5-37 and 7-48 nM d-1, respectively) were 10-fold higher than those in aerobic surface waters (0.04-3.8 nM d-1). The majority of CH4 oxidation, in terms of integrated activity, occurred within anoxic bottom waters. Water column oxidation reduced the potential lake-atmosphere CH4 flux by a factor of two to three. Measured oxidation rates and water column concentrations were used to estimate the biological turnover times of NH3 and CH4. The NH3 pool turns over rapidly, on time scales of 0.8 d in surface waters and 10 d within the oxycline, while CH4 is cycled on 103-d time scales in surface waters and 102-d time scales within oxycline and bottom waters. Our data suggest an important role for NH3 oxidation in alkaline, saline lakes since the process converts volatile NH3 to soluble NO2-, thereby reducing loss via lake-atmosphere exchange and maintaining nitrogen in a form that is readily available to phytoplankton.

  17. Laser direct write of planar alkaline microbatteries

    NASA Astrophysics Data System (ADS)

    Arnold, C. B.; Kim, H.; Piqué, A.

    We are developing a laser engineering approach to fabricate and optimize alkaline microbatteries in planar geometries. The laser direct-write technique enables multicapability for adding, removing and processing material and provides the ability to pattern complicated structures needed for fabricating complete microbattery assemblies. In this paper, we demonstrate the production of planar zinc-silver oxide alkaline cells under ambient conditions. The microbattery cells exhibit 1.55-V open-circuit potentials, as expected for the battery chemistry, and show a flat discharge behavior under constant-current loads. High capacities of over 450 μAhcm-2 are obtained for 5-mm2 microbatteries.

  18. Alkaline earth filled nickel skutterudite antimonide thermoelectrics

    DOEpatents

    Singh, David Joseph

    2013-07-16

    A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.

  19. Alkaline Capacitors Based on Nitride Nanoparticles

    NASA Technical Reports Server (NTRS)

    Aldissi, Matt

    2003-01-01

    High-energy-density alkaline electrochemical capacitors based on electrodes made of transition-metal nitride nanoparticles are undergoing development. Transition- metal nitrides (in particular, Fe3N and TiN) offer a desirable combination of high electrical conductivity and electrochemical stability in aqueous alkaline electrolytes like KOH. The high energy densities of these capacitors are attributable mainly to their high capacitance densities, which, in turn, are attributable mainly to the large specific surface areas of the electrode nanoparticles. Capacitors of this type could be useful as energy-storage components in such diverse equipment as digital communication systems, implanted medical devices, computers, portable consumer electronic devices, and electric vehicles.

  20. 21 CFR 184.1553 - Peptones.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., oligopeptides, and amino acids that are produced by partial hydrolysis of casein, animal tissue, soy protein... proteins listed in this paragraph with safe and suitable acids or heat. (b) The ingredients must be of...

  1. 21 CFR 184.1553 - Peptones.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., oligopeptides, and amino acids that are produced by partial hydrolysis of casein, animal tissue, soy protein... proteins listed in this paragraph with safe and suitable acids or heat. (b) The ingredients must be of...

  2. 21 CFR 184.1553 - Peptones.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., oligopeptides, and amino acids that are produced by partial hydrolysis of casein, animal tissue, soy protein... proteins listed in this paragraph with safe and suitable acids or heat. (b) The ingredients must be of...

  3. 21 CFR 184.1553 - Peptones.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., oligopeptides, and amino acids that are produced by partial hydrolysis of casein, animal tissue, soy protein... proteins listed in this paragraph with safe and suitable acids or heat. (b) The ingredients must be of...

  4. Sources of alkalinity and acidity along an acid mine drainage remediated stream in SE Ohio: Hewett Fork

    NASA Astrophysics Data System (ADS)

    Schleich, K. L.; Lopez, D. A.; Bowman, J. R.; Kruse, N. A.; Mackey, A. L.; VanDervort, D.; Korenowsky, R.

    2013-12-01

    In the remediation of acid mine drainage impacted streams, it is important to locate and quantify the sources of acidity and alkalinity inputs. These parameters affect the long-term recovery of the stream habitat. Previous studies have focused on treating the remediation of AMD as point source pollution, targeting the main acid seep for remediation. However, in the interest of biological and chemical recovery, it is important to understand how sources of alkalinity and acidity, throughout the stream, affect water and sediment quality. The Hewett Fork watershed in Southeastern Ohio is impacted by AMD from the AS-14 mine complex in Carbondale, Ohio. In attempts to remediate the stream, the water is being treated with a continuous alkaline input from a calcium oxide doser. While the section of watershed furthest downstream from the doser is showing signs of recovery, the water chemistry and aquatic life near the doser are still impacted. The objective of this study is to examine and model the chemistry of the tributaries of Hewett Fork to see how they contribute to the alkalinity and acidity budgets of the main stem of the stream. By examining the inputs of tributaries into the main stem, this project aims to understand processes occurring during remediation throughout the entire stream. Discharge was measured during a dry period in October, 2012 and at a high flow in May, 2013. Field parameters such as pH, TDS, DO, alkalinity and acidity were also determined. Low flow data collected during fall sampling shows variable flow along the stream path, the stream gains water from ground water at some points while it loses water at others, potentially due to variable elevation of the water table. Flow data collected during spring sampling shows that Hewett Fork is a gaining stream during that period with inputs from groundwater contributing to increasing flow downstream. When using this data to calculate the net alkalinity load along the stream, there are areas with alkaline

  5. Millimeter-scale alkalinity measurement in marine sediment using DET probes and colorimetric determination.

    PubMed

    Metzger, E; Viollier, E; Simonucci, C; Prévot, F; Langlet, D; Jézéquel, D

    2013-10-01

    Constrained DET (Diffusive Equilibration in Thin films) probes equipped with 75 sampling layers of agarose gel (DGT Research(©)) were used to sample bottom and pore waters in marine sediment with a 2 mm vertical resolution. After retrieval, each piece of hydrogel, corresponding to 25 μL, was introduced into 1 mL of colorimetric reagent (CR) solution consisting of formic acid and bromophenol blue. After the elution/reaction time, absorbance of the latter mixture was read at 590 nm and compared to a calibration curve obtained with the same protocol applied to mini DET probes soaked in sodium hydrogen carbonate standard solutions. This method allows rapid alkalinity determinations for the small volumes of anoxic pore water entrapped into the gel. The method was assessed on organic-rich coastal marine sediments from Thau lagoon (France). Alkalinity values in the overlying waters were in agreement with data obtained by classical sampling techniques. Pore water data showed a progressive increase of alkalinity in the sediment from 2 to 10 mmol kg(-1), corresponding to anaerobic respiration in organic-rich sediments. Moreover, replicates of high-resolution DET profiles showed important lateral heterogeneity at a decimeter scale. This underlines the importance of high-resolution spatial methods for alkalinity profiling in coastal marine systems.

  6. Alkaline Waterflooding Demonstration Project, Ranger Zone, Long Beach Unit, Wilmington Field, California. Fourth annual report, June 1979-May 1980. Volume 3. Appendices II-XVII

    SciTech Connect

    Carmichael, J.D.

    1981-03-01

    Volume 3 contains Appendices II through XVII: mixing instructions for sodium orthosilicate; oil displacement studies using THUMS C-331 crude oil and extracted reservoir core material from well B-110; clay mineral analysis of B-827-A cores; sieve analysis of 4 Fo sand samples from B-110-IA and 4 Fo sand samples from B-827-A; core record; delayed secondary caustic consumption tests; long-term alkaline consumption in reservoir sands; demulsification study for THUMS Long Beach Company, Island White; operating plans and instructions for DOE injection demonstration project, alkaline injection; caustic pilot-produced water test graphs; well test irregularities (6/1/79-5/31/80); alkaline flood pump changes (6/1/79-5/31/80); monthly DOE pilot chemical waterflood injection reports (preflush injection, alkaline-salt injection, and alkaline injection without salt); and caustic safety procedures-alkaline chemicals.

  7. The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?

    PubMed Central

    Schwalfenberg, Gerry K.

    2012-01-01

    This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine. PMID:22013455

  8. The alkaline diet: is there evidence that an alkaline pH diet benefits health?

    PubMed

    Schwalfenberg, Gerry K

    2012-01-01

    This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine.

  9. In situ arsenic removal in an alkaline clastic aquifer

    USGS Publications Warehouse

    Welch, A.H.; Stollenwerk, K.G.; Paul, A.P.; Maurer, D.K.; Halford, K.J.

    2008-01-01

    In situ removal of As from ground water used for water supply has been accomplished elsewhere in circum-neutral ground water containing high dissolved Fe(II) concentrations. The objective of this study was to evaluate in situ As ground-water treatment approaches in alkaline ground-water (pH > 8) that contains low dissolved Fe (water in the two aquifers studied are similar except for the inorganic As species. Although total inorganic As concentrations were similar, one aquifer has dominantly aqueous As(III) and the other has mostly As(V). Dissolved O2, Fe(II), and HCl were added to water and injected into the two aquifers to form Fe-oxide and lower the pH to remove As. Cycles of injection and withdrawal involved varying Fe(II) concentrations in the injectate. The As concentrations in water withdrawn from the two aquifers were as low as 1 and 6 ??g/L, with greater As removal from the aquifer containing As(V). However, Fe and Mn concentrations increased to levels greater than US drinking water standards during some of the withdrawal periods. A balance between As removal and maintenance of low Fe and Mn concentrations may be a design consideration if this approach is used for public-supply systems. The ability to lower As concentrations in situ in high-pH ground water should have broad applicability because similar high-As ground water is present in many parts of the world. ?? 2008.

  10. [Micirobial diversity and screening of antitumor activity of actinomycete strains from saline and alkaline environments in the Qinghai Province, P. R. China].

    PubMed

    Chen, Yi-Guang; Jiang, Yi; Li, Wen-Jun; Cui, Xiao-Long; Xu, Li-Hua

    2007-10-01

    Soil and sediment samples were collected from saline and alkaline soils or lakes in the Qinghai Province, northwestern China. 145 actinomycete strains were isolated using Glucose-Peptone-Yeast extract agar (GPY) and ISP medium 2 agar supplemented with 1.0 - 3.0 mol/L NaCl at pH 7.5 - 10. The antitumor activities in vitro of the fermentation broth extracts from the 145 test strains were detected in 6 human tumor cell lines (gastric cancer GXF251L, lung cancer LXFL529L, mammary cancer MAXF401NL, melanoma cancer MEXF462NL, renal cancer RXF486L and uterus cancer UXF1138L). Out of 145 test strains, 26 strains were positive in antitumor activities (17.9%), among them 19 strains belong to the genus Nocardiopsis, 7 strains belong to the genus Streptomyces. Then 8 antitumor-positive strains were submitted for 16S rRNA gene amplification and phylogenetic analysis after a comparison of antitumor activities, morphological, physiological characteristics and whole cell amino acids analysis. The results suggested that strain YIM 80139 is a member of a known Streptomyces species S. griseus, while strain YIM 80038 may represent a potential new Streptomyce species, and that the other 6 strains may represent 4 potential new species of the genus Nocardiopsis. The results presented above showed that actinomycetes isolated from saline and alkaline samples are important resources for bioactive compounds, and the abundant microbial diversity in the saline and alkaline environments in the Qinghai Province, Northwestern China is attractive for further investigation.

  11. Negative Electrode For An Alkaline Cell

    DOEpatents

    Coco, Isabelle; Cocciantelli, Jean-Michel; Villenave, Jean-Jacques

    1998-07-14

    The present invention concerns a negative electrode for an alkaline cell, comprising a current collector supporting a paste containing an electrochemically active material and a binder, characterized in that said binder is a polymer containing hydrophilic and hydrophobic groups, said polymer being selected from an acrylic homopolymer, copolymer and terpolymer, an unsaturated organic acid copolymer and an unsaturated acid anhydride copolymer.

  12. Alkaline electrochemical cells and method of making

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1970-01-01

    Equilibrated cellulose ether membranes of increased electrolytic conductivity for use as separators in concentrated alkaline electrochemical cells are investigated. The method of making such membranes by equilibration to the degree desired in an aqueous alkali solution mantained at a temperature below about 10 C is described.

  13. Kinetics of the alkaline hydrolysis of nitrocellulose.

    PubMed

    Christodoulatos, C; Su, T L; Koutsospyros, A

    2001-01-01

    Cellulose nitrate (nitrocellulose) is an explosive solid substance used in large quantities in various formulations of rocket and gun propellants. Safe destruction of nitrocellulose can be achieved by alkaline hydrolysis, which converts it to biodegradable products that can then be treated by conventional biological processes. The kinetics of the alkaline hydrolysis of munitions-grade nitrocellulose in sodium hydroxide solutions were investigated in completely mixed batch reactors. Experiments were conducted using solutions of alkaline strength ranging from 0.1 to 15% by mass and temperatures in the range of 30 to 90 degrees C. Regression analysis of the kinetic data revealed that alkaline hydrolysis of nitrocellulose is of the order 1.0 and 1.5 with respect to nitrocellulose and hydroxide concentration, respectively. The activation energy of the hydrolysis reaction was found to be 100.9 kJ/mol with a preexponential Arrhenius constant of 4.73 x 10(13). Nitrite and nitrate, in a 3:1 ratio, were the primary nitrogen species present in the posthydrolysis solution. The kinetic information is pertinent to the development and optimization of nitrocellulose chemical-biological treatment systems.

  14. MERCURIC CHLORIDE CAPTURE BY ALKALINE SORBENTS

    EPA Science Inventory

    The paper gives results of bench-scale mechanistic studies of mercury/sorbent reactions that showed that mercuric chloride (HgC12) is readily adsorbed by alkaline sorbents, which may offers a less expensive alternative to the use of activated carbons. A laboratory-scale, fixed-b...

  15. ISSUES WITH ALKALINE TREATMENT OF SLUDGE

    EPA Science Inventory

    This presentation begins with a discussion of the use of lime and other alkaline materials from the very earliest times to the present for killing bacteria, viruses and parasites and for controlling odors in wastewaters and sludge. It answers the question "How did EPA arrive at i...

  16. Alkaline phosphatase revisited: hydrolysis of alkyl phosphates.

    PubMed

    O'Brien, Patrick J; Herschlag, Daniel

    2002-03-05

    Escherichia coli alkaline phosphatase (AP) is the prototypical two metal ion catalyst with two divalent zinc ions bound approximately 4 A apart in the active site. Studies spanning half a century have elucidated many structural and mechanistic features of this enzyme, rendering it an attractive model for investigating the potent catalytic power of bimetallic centers. Unfortunately, fundamental mechanistic features have been obscured by limitations with the standard assays. These assays generate concentrations of inorganic phosphate (P(i)) in excess of its inhibition constant (K(i) approximately 1 muM). This tight binding by P(i) has affected the majority of published kinetic constants. Furthermore, binding limits k(cat)/K(m) for reaction of p-nitrophenyl phosphate, the most commonly employed substrate. We describe a sensitive (32)P-based assay for hydrolysis of alkyl phosphates that avoids the complication of product inhibition. We have revisited basic mechanistic features of AP with these alkyl phosphate substrates. The results suggest that the chemical step for phosphorylation of the enzyme limits k(cat)/K(m). The pH-rate profile and additional results suggest that the serine nucleophile is active in its anionic form and has a pK(a) of < or = 5.5 in the free enzyme. An inactivating pK(a) of 8.0 is observed for binding of both substrates and inhibitors, and we suggest that this corresponds to ionization of a zinc-coordinated water molecule. Counter to previous suggestions, inorganic phosphate dianion appears to bind to the highly charged AP active site at least as strongly as the trianion. The dependence of k(cat)/K(m) on the pK(a) of the leaving group follows a Brønsted correlation with a slope of beta(lg) = -0.85 +/- 0.1, differing substantially from the previously reported value of -0.2 obtained from data with a less sensitive assay. This steep leaving group dependence is consistent with a largely dissociative transition state for AP-catalyzed hydrolysis of

  17. Alkaline earth metal catalysts for asymmetric reactions.

    PubMed

    Kobayashi, Shū; Yamashita, Yasuhiro

    2011-01-18

    The group 2 alkaline earth metals calcium (Ca), strontium (Sr), and barium (Ba) are among the most common elements on Earth, abundant in both the sea and the Earth's crust. Although they are familiar in our daily lives, their application to organic synthesis has, so far, been limited. Some particularly useful properties of these elements include (i) low electronegativity, (ii) a stable oxidation state of +2, meaning that they can potentially form two covalent bonds with anions, and (iii) the ability to occupy a variety of coordination sites due to their large ionic radius. Furthermore, the alkaline earth metals, found between the group 1 and group 3 elements, show mild but significant Lewis acidity, which can be harnessed to control coordinative molecules via a Lewis acid-base interaction. Taken together, these characteristics make the metals Ca, Sr, and Ba very promising components of highly functionalized acid-base catalysts. In this Account, we describe the development of chiral alkaline earth metal catalysts for asymmetric carbon-carbon bond-forming reactions. Recently prepared chiral alkaline earth metal complexes have shown high diastereo- and enantioselectivities in fundamental and important chemical transformations. We chose chiral bisoxazoline (Box) derivatives bearing a methylene tether as a ligand for chiral modification. These molecules are very useful because they can covalently coordinate to alkaline earth metals in a bidentate fashion through deprotonation of the tether portion. It was found that chiral calcium-Box complexes could successfully promote catalytic asymmetric 1,4-addition and [3 + 2] cycloaddition reactions with high diastereo- and enantioselectivities. Both the calcium-Box complexes and chiral strontium-bis-sulfonamide and chiral barium-BINOLate complexes could catalyze asymmetric 1,4-addition reactions with high enantioselectivities. Furthermore, we designed a calcium-neutral coordinative ligand complex as a new type of chiral alkaline

  18. Crystal structure of alkaline cellulase K: insight into the alkaline adaptation of an industrial enzyme.

    PubMed

    Shirai, T; Ishida, H; Noda, J; Yamane, T; Ozaki, K; Hakamada, Y; Ito, S

    2001-07-27

    The crystal structure of the catalytic domain of alkaline cellulase K was determined at 1.9 A resolution. Because of the most alkaliphilic nature and it's highest activity at pH 9.5, it is used commercially in laundry detergents. An analysis of the structural bases of the alkaliphilic character of the enzyme suggested a mechanism similar to that previously proposed for alkaline proteases, that is, an increase in the number of Arg, His, and Gln residues, and a decrease in Asp and Lys residues. Some ion pairs were formed by the gained Arg residues, which is similar to what has been found in the alkaline proteases. Lys-Asp ion pairs are disfavored and partly replaced with Arg-Asp ion pairs. The alkaline adaptation appeared to be a remodeling of ion pairs so that the charge balance is kept in the high pH range.

  19. Ozonation and alkaline-peroxide pretreatment of wheat straw for Cryptococcus curvatus fermentation

    NASA Technical Reports Server (NTRS)

    Greenwalt, C. J.; Hunter, J. B.; Lin, S.; McKenzie, S.; Denvir, A.

    2000-01-01

    Crop residues in an Advanced Life Support System (ALS) contain many valuable components that could be recovered and used. Wheat is 60% inedible, with approximately 90% of the total sugars in the residue cellulose and hemicellulose. To release these sugars requires pretreatment followed by enzymatic hydrolysis. Cryptococcus curvatus, an oleaginous yeast, uses the sugars in cellulose and hemicellulose for growth and production of storage triglycerides. In this investigation, alkaline-peroxide and ozonation pretreatment methods were compared for their efficiency to release glucose and xylose to be used in the cultivation of C. curvatus. Leaching the biomass with water at 65 degrees C for 4 h prior to pretreatment facilitated saccharification. Alkaline-peroxide and ozone pretreatment were almost 100% and 80% saccharification efficient, respectively. The sugars derived from the hydrolysis of alkaline-peroxide-treated wheat straw supported the growth of C. curvatus and the production of edible single-cell oil.

  20. Interfacial activity in alkaline flooding enhanced oil recovery

    SciTech Connect

    Chan, M.K.

    1981-01-01

    The ionization of long-chained organic acids in the crude oil to form soaps was shown to be primarily responsible for the lowering of oil-water interfacial tension at alkaline pH. These active acids can be concentrated by silica gel chromatography into a minor polar fraction. An equilibrium chemical model was proposed based on 2 competing reactions: the ionization of acids to form active anions, and the formation of undissociated soap between acid anions and sodium ions. It correlates the interfacial activity with the interfacial concentration of active acid anions which is expressed in terms of the concentrations of the chemical species in the system. The model successfully predicts the observed oil-alkaline solution interfacial phenomenon, including its dependence on pH, alkali and salt concentrations, type of acid present and type of soap formed. Flooding at different alkali concentrations to activate different acid species present in the crude was shown to give better recovery than flooding at a single high alkali concentration. Treating the crude oil with a dilute solution of mineral acids liberates additional free active acids and yields better interfacial activity during subsequent alkali contact.

  1. Mobilization of Manufactured Gas Plant Tar with Alkaline Flushing Solutions

    PubMed Central

    Hauswirth, Scott C.; Birak, Pamela Schultz; Rylander, Seth C.; Miller, Cass T.

    2011-01-01

    This experimental study investigates the use of alkaline and alkaline-polymer solutions for the mobilization of former manufactured gas plant (FMGP) tars. Tar-aqueous interfacial tensions (IFTs) and contact angles were measured, and column flushing experiments were conducted. NaOH solutions (0.01–1 wt.%) were found to significantly reduce tar-aqueous IFT. Contact angles indicated a shift to strongly water-wet, then to tar-wet conditions as NaOH concentration increased. Column experiments were conducted with flushing solutions containing 0.2, 0.35, and 0.5% NaOH, both with and without xanthan gum (XG). Between 10 and 44% of the residual tar was removed by solutions containing only NaOH, while solutions containing both NaOH and XG removed 81–93% of the tar with final tar saturations as low as 0.018. The mechanism responsible for the tar removal is likely a combination of reduced IFT, a favorable viscosity ratio, and tar bank formation. Such an approach may have practical applications and would be significantly less expensive than surfactant-based methods. PMID:22091957

  2. Comparing alkaline and thermal disintegration characteristics for mechanically dewatered sludge.

    PubMed

    Tunçal, Tolga

    2011-10-01

    Thermal drying is one of the advanced technologies ultimately providing an alternative method of sludge disposal. In this study, the drying kinetics of mechanically dewatered sludge (MDS) after alkaline and thermal disintegration have been studied. In addition, the effect of total organic carbon (TOC) on specific resistance to filtration and sludge bound water content were also investigated on freshly collected sludge samples. The combined effect of pH and TOC on the thermal sludge drying rate for MDS was modelled using the two-factorial experimental design method. Statistical assessment of the obtained results proposed that sludge drying potential has increased exponentially for both increasing temperature and lime dosage. Execution of curve fitting algorithms also implied that drying profiles for raw and alkaline-disintegrated sludge were well fitted to the Henderson and Pabis model. The activation energy of MDS decreased from 28.716 to 11.390 kJ mol(-1) after disintegration. Consequently, the unit power requirement for thermal drying decreased remarkably from 706 to 281 W g(-1) H2O.

  3. Impacts of Priming with Silicon on the Growth and Tolerance of Maize Plants to Alkaline Stress

    PubMed Central

    Abdel Latef, Arafat A.; Tran, Lam-Son P.

    2016-01-01

    Silicon (Si) has been known to augment plant defense against biotic and abiotic pressures. Maize (Zea maize L.) is classified as a Si accumulator and is relatively susceptible to alkaline stress. In this study, seeds of maize were grown in pots and exposed to various concentrations of Na2CO3 (0, 25, 50, and 75 mM) with or without 1.5 mM Si in the form of sodium metasilicate Na2O3Si.5H2O for 25 days. Alkaline-stressed plants showed a decrease in growth parameters, leaf relative water content (LRWC), and the contents of photosynthetic pigments, soluble sugars, total phenols and potassium ion (K+), as well as potassium/sodium ion (K+/Na+) ratio. By contrast, alkaline stress increased the contents of soluble proteins, total free amino acids, proline, Na+ and malondialdehyde (MDA), as well as the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in stressed plants. On the other hand, application of Si by seed-priming improved growth of stressed plants, which was accompanied by the enhancement in LRWC, and levels of photosynthetic pigments, soluble sugars, soluble proteins, total free amino acids and K+, as well as activities of SOD, CAT, and POD enzymes. Furthermore, Si supplement resulted in a decrease in the contents of proline, MDA and Na+, which together with enhanced K+ level led to a favorable adjustment of K+/Na+ ratio, in stressed plants relative to plants treated with alkaline stress alone. Taken together, these results indicate that Si plays a pivotal role in alleviating the negative effects of alkaline stress on maize growth by improving water status, enhancing photosynthetic pigments, accumulating osmoprotectants rather than proline, activating the antioxidant machinery, and maintaining the balance of K+/Na+ ratio. Thus, our findings demonstrate that seed-priming with Si is an efficient strategy that can be used to boost tolerance of maize plants to alkaline stress. PMID:27014283

  4. Impacts of Priming with Silicon on the Growth and Tolerance of Maize Plants to Alkaline Stress.

    PubMed

    Abdel Latef, Arafat A; Tran, Lam-Son P

    2016-01-01

    Silicon (Si) has been known to augment plant defense against biotic and abiotic pressures. Maize (Zea maize L.) is classified as a Si accumulator and is relatively susceptible to alkaline stress. In this study, seeds of maize were grown in pots and exposed to various concentrations of Na2CO3 (0, 25, 50, and 75 mM) with or without 1.5 mM Si in the form of sodium metasilicate Na2O3Si.5H2O for 25 days. Alkaline-stressed plants showed a decrease in growth parameters, leaf relative water content (LRWC), and the contents of photosynthetic pigments, soluble sugars, total phenols and potassium ion (K(+)), as well as potassium/sodium ion (K(+)/Na(+)) ratio. By contrast, alkaline stress increased the contents of soluble proteins, total free amino acids, proline, Na(+) and malondialdehyde (MDA), as well as the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in stressed plants. On the other hand, application of Si by seed-priming improved growth of stressed plants, which was accompanied by the enhancement in LRWC, and levels of photosynthetic pigments, soluble sugars, soluble proteins, total free amino acids and K(+), as well as activities of SOD, CAT, and POD enzymes. Furthermore, Si supplement resulted in a decrease in the contents of proline, MDA and Na(+), which together with enhanced K(+) level led to a favorable adjustment of K(+)/Na(+) ratio, in stressed plants relative to plants treated with alkaline stress alone. Taken together, these results indicate that Si plays a pivotal role in alleviating the negative effects of alkaline stress on maize growth by improving water status, enhancing photosynthetic pigments, accumulating osmoprotectants rather than proline, activating the antioxidant machinery, and maintaining the balance of K(+)/Na(+) ratio. Thus, our findings demonstrate that seed-priming with Si is an efficient strategy that can be used to boost tolerance of maize plants to alkaline stress.

  5. [Leucocyte alkaline phosphatase in normal and pathological pregnancy (author's transl)].

    PubMed

    Stark, K H; Zaki, I; Sobolewski, K

    1981-01-01

    The activities of leucocyte alkaline phosphatase were determined in 511 patients with normal and pathological pregnancy. Mean values were compared and the enzyme followed up, and the conclusion was drawn that leucocyte alkaline phosphatase was no safe indicator of foetal condition. No direct relationship were found to exist between leucocyte alkaline phosphatase, total oestrogens, HSAP, HLAP, HPL, and oxytocinase.

  6. Coupling the Alkaline-Surfactant-Polymer Technology and The Gelation Technology to Maximize Oil Production

    SciTech Connect

    Malcolm Pitts; Jie Qi; Dan Wilson; David Stewart; Bill Jones

    2005-10-01

    was improved by 596,000 bbls when a gel was placed in the B sand. Alkaline-surfactant-polymer flood oil recovery improvement over a waterflood was 392,000 bbls. Placing a gel into the B sand prior to an alkaline-surfactant-polymer flood resulted in 989,000 bbl more oil than only water injection.

  7. Surfactant-enhanced alkaline flooding field project

    SciTech Connect

    French, T.R.

    1991-10-01

    The Tucker sand of Helper (KS) field is a candidate for surfactant-enhanced alkaline flooding. The geology of the Helper site is typical of many DOE Class I reservoirs. The Tucker sand of Helper field was deposited in a fluvial dominated deltaic environment. Helper oil can be mobilized with either chemical system 2 or chemical system 3, as described in this report. Oil fields in the Gulf Coast region are also good candidates for surfactant-enhanced alkaline flooding. The results from laboratory tests conducted in Berea sandstone cores with oil brine from Helper (KS) field are encouraging. The crude oil is viscous and non-acidic and, yet, was mobilized by the chemical formulations described in this report. Significant amounts of the oil were mobilized under simulated reservoir conditions. The results in Berea sandstone cores were encouraging and should be verified by tests with field core. Consumption of alkali, measured with field core, was very low. Surfactant loss appeared to be acceptable. Despite the good potential for mobilization of Helper oil, certain reservoir characteristics such as low permeability, compartmentalization, and shallow depth place constraints on applications of any chemical system in the Tucker sand. These constraints are typical of many DOE Class I reservoirs. Although Hepler field is not a perfect reservoir in which to apply surfactant- enhanced alkaline flooding, Hepler oil is particularly amenable to mobilization by surfactant-enhanced alkaline systems. A field test is recommended, dependent upon final evaluation of well logs and cores from the proposed pilot area. 14 refs., 21 figs., 10 tabs.

  8. The alkaline earth intercalates of molybdenum disulfide

    NASA Technical Reports Server (NTRS)

    Somoano, R. B.; Hadek, V.; Rembaum, A.; Samson, S.; Woollam, J. A.

    1975-01-01

    Molybdenum disulfide has been intercalated with calcium and strontium by means of the liquid ammonia technique. Chemical, X-ray, and superconductivity data are presented. The X-ray data reveal a lowering of crystal symmetry and increase of complexity of the structure upon intercalation with the alkaline earth metals. The Ca and Sr intercalates start to superconduct at 4 and 5.6 K, respectively, and show considerable anisotropy regarding the critical magnetic field.

  9. Alkaline earth cation extraction from acid solution

    DOEpatents

    Dietz, Mark; Horwitz, E. Philip

    2003-01-01

    An extractant medium for extracting alkaline earth cations from an aqueous acidic sample solution is described as are a method and apparatus for using the same. The separation medium is free of diluent, free-flowing and particulate, and comprises a Crown ether that is a 4,4'(5')[C.sub.4 -C.sub.8 -alkylcyclohexano]18-Crown-6 dispersed on an inert substrate material.

  10. Oxidation catalysts on alkaline earth supports

    DOEpatents

    Mohajeri, Nahid

    2017-03-21

    An oxidation catalyst includes a support including particles of an alkaline earth salt, and first particles including a palladium compound on the support. The oxidation catalyst can also include precious metal group (PMG) metal particles in addition to the first particles intermixed together on the support. A gas permeable polymer that provides a continuous phase can completely encapsulate the particles and the support. The oxidation catalyst may be used as a gas sensor, where the first particles are chemochromic particles.

  11. Inhibition of Alkaline Phosphatase by Several Diuretics

    DTIC Science & Technology

    1980-01-01

    August 20th, 1979) . . Summary , . Acetazolamide, furosemide, ethacrynic acid and chlorothiazide, diuretics of considerable structural diversity, inhibit...Ki is calculated to be 8.4, 7.0, 2.8 and 0.1 mmol/l for acetazolamide, furosemide, ethacrynic acid and chlorothiazide, respectively. Chlorothiazide...is a much more potent inhibitor of alkaline phos- phatase than the other three diuretics. The combination of ethacrynic acid and cysteine, itself an

  12. Alkaline flooding for enhanced oil recovery

    SciTech Connect

    Gittler, W.E.

    1983-09-01

    There are over 12 active projects of varying size using one of 3 major types of alkaline agents. These include sodium silicate, caustic soda, and soda ash. Among the largest pilots currently is the THUMS project in the Wilmington field, California. Plans called for the injection of a 4% weight concentration of sodium orthosilicate over a 60% PV. Through the first 3 yr, over 27 million bbl of chemicals have been injected. Gulf Oil is operating several alkaline floods, one of which is located off shore in the Quarantine Bay field, Louisiana. In this pilot, sodium hydroxide in a weight concentration of 5 to 12% is being injected. Belco Petroleum Corp. has reported that their pilot operating in the Isenhour Unit in Wyoming is using a .5% weight concentration of soda ash in conjunction with a polymer. Other uses for alkaline agents in chemical flooding include the use of silicate as a preflush or sacrificial agent in micellar/polymer and surfactant recovery systems. In addition, caustic has been tested in the surface-mixed caustic emulsion process while orthosilicate has been tested in a recovery method known as mobility-controlled caustic floods.

  13. Alkaline phosphatase of Physarum polycephalum is insoluble.

    PubMed

    Furuhashi, Kiyoshi

    2008-02-01

    The plasmodia of Physarum polycephalum grow as multinucleated cells in the presence of sufficient humidity and nutriment. Under non-illuminating conditions, stresses such as low temperature or high concentrations of salts transform the plasmodia into spherules whereas dehydration induces sclerotization. Some phosphatases including protein phosphatase and acid phosphatase have been purified from the plasmodia, but alkaline phosphatase remains to be elucidated. Phosphatase of the plasmodia, spherules and sclerotia was visualized by electrophoresis gel-staining assay using 5-bromo-4-chloro-3-indolyl phosphate. Insoluble fractions of the sclerotia were abundant in phosphatase activity. The phosphatase which was extracted by nonionic detergent was subjected to column chromatography and preparative electrophoresis. Purified phosphatase showed the highest activity at pH 8.8, indicating that this enzyme belongs to alkaline phosphatase. The apparent molecular mass from sodium dodecyl sulfate-polyacrylamide gel electrophoresis under non-reducing condition was estimated to be 100 kDa whereas that under reducing was 105 kDa. An amount of 1% sodium dodecyl sulfate or 0.5 M NaCl had no effects on the activity although the phosphatase showed heat instability, Mg(2+)-dependency and sensitivity to 2-glycerophosphate or NaF. The extracting conditions and enzymatic properties suggest that this alkaline phosphatase which is in a membrane-bound form plays important roles in phosphate metabolism.

  14. Mechanism and models for zinc metal morphology in alkaline media

    NASA Technical Reports Server (NTRS)

    May, C. E.; Kautz, H. E.

    1981-01-01

    Based on experimental observations, a mechanism is presented to explain existence of the different morphologies of electrodeposited zinc in alkaline solution. The high current density dendrites appear to be due to more rapid growth on the nonbasal crystallographic planes than on the basal plane. The low current density moss apparently results from dissolution from the nonbasal planes at low cathodic voltages. Electrochemical models were sought which would produce such a phenomenon. The fundamental plating mechanism alone accounts only for different rates on different planes, not for zinc dissolution from a plane in the cathodic region. Fourteen models were explored; two models were in accord with the proposed mechanism. One involves rapid disproportionation of the zinc +1 species on the nonbasal planes. The other involves a redox reaction (corrosion) between the zinc-zincate and hydrogen-water systems.

  15. Alkaline regenerative fuel cell systems for energy storage

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Reid, M. A.; Martin, R. E.

    1981-01-01

    A description is presented of the results of a preliminary design study of a regenerative fuel cell energy storage system for application to future low-earth orbit space missions. The high energy density storage system is based on state-of-the-art alkaline electrolyte cell technology and incorporates dedicated fuel cell and electrolysis cell modules. In addition to providing energy storage, the system can provide hydrogen and oxygen for attitude control of the satellite and for life support. During the daylight portion of the orbit the electrolysis module uses power provided by the solar array to generate H2 and O2 from the product water produced by the fuel cell module. The fuel cell module supplies electrical power during the dark period of the orbit.

  16. Mesozoic mafic alkaline magmatism of southern Scandinavia

    NASA Astrophysics Data System (ADS)

    Tappe, Sebastian

    2004-11-01

    More than 100 volcanic necks in central Scania (southern Sweden) are the product of Jurassic continental rift-related mafic alkaline magmatism at the southwest margin of the Baltic Shield. They are mainly basanites, with rarer melanephelinites. Both rock groups display overlapping primitive Mg-numbers, Cr and Ni contents, steep chondrite-normalized rare earth element patterns (LaN /YbN = 17 27) and an overall enrichment in incompatible elements. However, the melanephelinites are more alkaline and have stronger high field strength element enrichment than the basanites. The existence of distinct primary magmas is also indicated by heterogeneity in highly incompatible element ratios (e.g. Zr/Nb, La/Nb). Trace element modelling indicates that the magmas were generated by comparably low degrees of melting of a heterogeneous mantle source. Such a source can best be explained by a metasomatic overprint of the mantle lithosphere by percolating evolved melts. The former existence of such alkaline trace element-enriched melts can be demonstrated by inversion of the trace element content of green-core clinopyroxenes and anorthoclase which occur as xenocrysts in the melanephelinites and are interpreted as being derived from crystallization of evolved mantle melts. Jurassic magmatic activity in Scania was coeval with the generation of nephelinites in the nearby Egersund Basin (Norwegian North Sea). Both Scanian and North Sea alkaline magmas share similar trace element characteristics. Mantle enrichment processes at the southwest margin of the Baltic Shield and the North Sea Basin generated trace element signatures similar to those of ocean island basalts (e.g. low Zr/Nb and La/Nb) but there are no indications of plume activity during the Mesozoic in this area. On the contrary, the short duration of rifting, absence of extensive lithospheric thinning, and low magma volumes argue against a Mesozoic mantle plume. It seems likely that the metasomatic imprint resulted from the

  17. Alkaline and ultrasound assisted alkaline pretreatment for intensification of delignification process from sustainable raw-material.

    PubMed

    Subhedar, Preeti B; Gogate, Parag R

    2014-01-01

    Alkaline and ultrasound-assisted alkaline pretreatment under mild operating conditions have been investigated for intensification of delignification. The effect of NaOH concentration, biomass loading, temperature, ultrasonic power and duty cycle on the delignification has been studied. Most favorable conditions for only alkaline pretreatment were alkali concentration of 1.75 N, solid loading of 0.8% (w/v), temperature of 353 K and pretreatment time of 6 h and under these conditions, 40.2% delignification was obtained. In case of ultrasound-assisted alkaline approach, most favorable conditions obtained were alkali concentration of 1N, paper loading of 0.5% (w/v), sonication power of 100 W, duty cycle of 80% and pretreatment time of 70 min and the delignification obtained in ultrasound-assisted alkaline approach under these conditions was 80%. The material samples were characterized by FTIR, SEM, XRD and TGA technique. The lignin was recovered from solution by precipitation method and was characterized by FTIR, GPC and TGA technique.

  18. Alkaline solution/binder ratio as a determining factor in the alkaline activation of aluminosilicates

    SciTech Connect

    Ruiz-Santaquiteria, C.; Fernandez-Jimenez, A.; Palomo, A.

    2012-09-15

    This study investigates the effect of the alkaline solution/binder (S/B) ratio on the composition and nanostructure of the reaction products generated in the alkaline activation of aluminosilicates. The experiments used two mixtures of fly ash and dehydroxylated white clay and for each of these, varying proportions of the solution components. The alkali activator was an 8 M NaOH solution (with and without sodium silicate) used at three S/B ratios: 0.50, 0.75 and 1.25. The {sup 29}Si, {sup 27}Al MAS NMR and XRD characterisation of the reaction products reveal that for ratios nearest the value delivering suitable paste workability, the reaction-product composition and structure depend primarily on the nature and composition of the starting materials and the alkaline activator used. However, when an excess alkaline activator is present in the system, the reaction products tend to exhibit SiO{sub 2}/Al{sub 2}O{sub 3} ratios of approximately 1, irrespective of the composition of the starting binder or the alkaline activator.

  19. An alkaline approach to treating cooling towers for control of Legionella pneumophila.

    PubMed Central

    States, S J; Conley, L F; Towner, S G; Wolford, R S; Stephenson, T E; McNamara, A M; Wadowsky, R M; Yee, R B

    1987-01-01

    Earlier field and laboratory studies have shown that Legionella species survive and multiply in the pH range 5.5 to 9.2. Additionally, the technical feasibility of operating cooling towers at elevated alkalinities and pH has previously been documented by published guidelines. The guidelines indicate that these conditions facilitate corrosion control and favor chlorine persistence which enhances the effectiveness of continuous chlorination in biofouling control. This information suggests that control of Legionella species in cooling towers can be accomplished by operating the towers under alkaline conditions. To test this possibility, we collected water samples over a period of months from a hospital cooling tower. The samples were analyzed for a variety of chemical parameters. Subsamples were pasteurized and inoculated with non-agar-passaged Legionella pneumophila which had been maintained in tap water. Correlation of subsequent Legionella growth with corresponding pH and alkalinity values revealed statistically significant inverse associations. These data support the hypothesis that operating cooling towers outside of the optimal conditions for Legionella growth (e.g., at elevated alkalinities and a pH greater than 9) may be a useful approach to controlling growth in this habitat. PMID:3662515

  20. Block copolymers for alkaline fuel cell membrane materials

    NASA Astrophysics Data System (ADS)

    Li, Yifan

    Alkaline fuel cells (AFCs) using anion exchange membranes (AEMs) as electrolyte have recently received considerable attention. AFCs offer some advantages over proton exchange membrane fuel cells, including the potential of non-noble metal (e.g. nickel, silver) catalyst on the cathode, which can dramatically lower the fuel cell cost. The main drawback of traditional AFCs is the use of liquid electrolyte (e.g. aqueous potassium hydroxide), which can result in the formation of carbonate precipitates by reaction with carbon dioxide. AEMs with tethered cations can overcome the precipitates formed in traditional AFCs. Our current research focuses on developing different polymer systems (blend, block, grafted, and crosslinked polymers) in order to understand alkaline fuel cell membrane in many aspects and design optimized anion exchange membranes with better alkaline stability, mechanical integrity and ionic conductivity. A number of distinct materials have been produced and characterized. A polymer blend system comprised of poly(vinylbenzyl chloride)-b-polystyrene (PVBC-b-PS) diblock copolymer, prepared by nitroxide mediated polymerization (NMP), with poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) or brominated PPO was studied for conversion into a blend membrane for AEM. The formation of a miscible blend matrix improved mechanical properties while maintaining high ionic conductivity through formation of phase separated ionic domains. Using anionic polymerization, a polyethylene based block copolymer was designed where the polyethylene-based block copolymer formed bicontinuous morphological structures to enhance the hydroxide conductivity (up to 94 mS/cm at 80 °C) while excellent mechanical properties (strain up to 205%) of the polyethylene block copolymer membrane was observed. A polymer system was designed and characterized with monomethoxy polyethylene glycol (mPEG) as a hydrophilic polymer grafted through substitution of pendent benzyl chloride groups of a PVBC

  1. Multi proxy approach for the formation of calcium carbonates in alkaline man-made environments

    NASA Astrophysics Data System (ADS)

    Rinder, T.; Dietzel, M.; Leis, A.

    2009-04-01

    The formation of calcium carbonates, e.g. in drainage systems of tunnels, may be induced by degassing of CO2-rich groundwater which enters the building. However, the dissolution of portlandite (Ca(OH)2) from cements or the shotcrete of the tunnel wall bears an additional and immense potential for the formation of carbonates from alkaline solutions. Variations in trace element incorporation and distribution of the stable isotopes of carbon and oxygen in the precipitated calcium carbonates may represent powerful tools to identify individual mechanisms for carbonate formation. As portlandite dissolves, highly alkaline solutions are obtained. In this case, precipitation of calcium carbonate can be related to the absorption of CO2 from the atmosphere. Isotopic analyses of the calcite show that fixation of CO2 from the Earth's atmosphere leads to significantly lighter ^13Ccalcite values (down to -25 o/oo, VPDB) as expected for the fixation of groundwater carbonate (typical ^13Ccalcite values between -10 and -16o/oo, VPDB). The evolution of Sr/Ca ratios in the alkaline drainage solutions and in the corresponding calcium carbonate precipitation provides insight into the dissolution process at the concrete with respect to the amount of primarily dissolved portlandite from the cement. Moreover, an inverse relationship between Mg/Ca and Sr/Ca ratios is observed due to the liberation of aqueous strontium by the dissolution of portlandite and the formation of brucite (Mg(OH)2) at alkaline conditions. Less incorporation of magnesium in the calcite structure is a strong indicator for carbonate precipitation from highly alkaline environments. Applications of such multi proxy approaches are discussed with case studies. Main tasks are the reconstruction of the environmental conditions during primary CaCO3 formation and monitoring of ongoing precipitation of calcium carbonates and cement-water interaction in alkaline man-made environments.

  2. Isolation of a Sulfur-oxidizing Bacterium That can Grow under Alkaline pH, from Corroded Concrete.

    PubMed

    Maeda, T; Negishi, A; Oshima, Y; Nogami, Y; Kamimura, K; Sugio, T

    1998-01-01

    To study the early stages of concrete corrosion by bacteria, sulfur-oxidizing bacterium strain RO-1, which grows in an alkaline thiosulfate medium (pH 10.0) was isolated from corroded concreate and characterized. Strain RO-1 was a Gram negative, rod-shaped bacterium (0.5-0.6×0.9-1.5 μm). The mean G+C content of the DNA of strain RO-1 was 65.0 mol%. Optimum pH and temperature for growth were 8.0. and 30-37°C, respectively. When grown in thiosulfate medium with pH 10.0, growth rate of the strain was 48% of that observed at the optimum pH for growth. Strain RO-1 used sulfide, thiosulfate, and glucose, but not elemental sulfur or tetrathionate, as a sole energy source. Strain RO-1 grew under anaerobic conditions in pepton-NO3 (-) medium containing sodium nitrate as an electron acceptor, and had enzyme activities that oxidized sulfide, elemental sulfur, thiosulfate, sulfite, and glucose, but not tetrathionate. The bacterium had an activity to assimilate (14)CO2 into the cells when thiosulfate was used as an energy source. These results suggest that strain RO-1 is Thiobacillus versutus. Strain RO-1 exuded Ca(2+) from concrete blocks added to thiosulfate medium with pH 9.0 and the pH of the medium decreased from 9.0 to 5.5 after 22 days of cultivation. In contrast, Thiobacillus thiooxidans strain NB1-3 could not exude Ca(2+) in the same thiosulfate medium, suggesting that strain RO-1, but not T. thiooxidans NB1-3, is involved in the early stage of concrete corrosion because concrete structures just after construction contain calcium hydroxide and have a pH of 12-13.

  3. Water

    USGS Publications Warehouse

    Leopold, Luna Bergere; Baldwin, Helene L.

    1962-01-01

    What do you use water for?If someone asked you this question you would probably think right away of water for drinking. Then you would think of water for bathing, brushing teeth, flushing the toilet. Your list would get longer as you thought of water for cooking, washing the dishes, running the garbage grinder. Water for lawn watering, for play pools, for swimming pools, for washing the car and the dog. Water for washing machines and for air conditioning. You can hardly do without water for fun and pleasure—water for swimming, boating, fishing, water-skiing, and skin diving. In school or the public library, you need water to wash your hands, or to have a drink. If your home or school bursts into flames, quantities of water are needed to put it out.In fact, life to Americans is unthinkable without large supplies of fresh, clean water. If you give the matter a little thought, you will realize that people in many countries, even in our own, may suffer from disease and dirt simply because their homes are not equipped with running water. Imagine your own town if for some reason - an explosion, perhaps - water service were cut off for a week or several weeks. You would have to drive or walk to a neighboring town and bring water back in pails. Certainly if people had to carry water themselves they might not be inclined to bathe very often; washing clothes would be a real chore.Nothing can live without water. The earth is covered by water over three-fourths of its surface - water as a liquid in rivers, lakes and oceans, and water as ice and snow on the tops of high mountains and in the polar regions. Only one-quarter of our bodies is bone and muscle; the other three-fourths is made of water. We need water to live, and so do plants and animals. People and animals can live a long time without food, but without water they die in a few days. Without water, everything would die, and the world would turn into a huge desert.

  4. Enhanced coagulation with polyaluminum chlorides: role of pH/alkalinity and speciation.

    PubMed

    Yan, Mingquan; Wang, Dongsheng; Yu, Jianfeng; Ni, Jinren; Edwards, Marc; Qu, Jiuhui

    2008-04-01

    Enhanced coagulation is considered to be among the best available techniques (BAT) for disinfection by-product (DBP) precursor removal in water treatment. Improving existing understanding requires further consideration of nuances of chemical speciation relative to source water chemistry. In this paper, the effect of alkalinity/pH and speciation on inorganic polymer flocculants, polyaluminum chlorides (PACls) for enhanced particle and natural organic matter (NOM) removal was investigated. Three kinds of well-characterized typical source waters in China with low, moderate, and high alkalinity were selected. Performance of coagulants is controlled not only by preformed species but also by those formed in situ. At neutral and basic pH values, PACls with higher basicity (ratio of OH(-)/Al), which have more stable preformed Alb (the rapid reacted species as in ferron assay), are more efficient for turbidity and NOM removal. At slightly acidic pH, PACls with lower basicity are more efficient since more Alb can be formed in situ. Optimal NOM removal was achieved at pH 5.5-6.5 for all PACls. Basicity, speciation, and dosage of coagulant should be optimized based on raw water alkalinity to enhance the removal efficiency of NOM.

  5. Desialylated alkaline phosphatase: activation by 4-nitrophenol.

    PubMed

    Nayudu, P R

    1984-01-01

    Mouse ileal alkaline phosphatase is a sialyl enzyme (12-14 moles per mole of enzyme). When partially desialylated by treatment with neuraminidase, the enzyme loses most of its activity, associated with reduced apparent Vmax and Km. Part of that loss, however, is recovered as the product 4-nitrophenol's concentration builds up in the cuvette. Experimental results are presented to demonstrate that the activation is due to the binding of 4-nitrophenol as a ligand by the partially desialylated enzyme and that both the loss of activity by sialic acid removal and activation by ligand-binding are correlated with changes in protein conformation.

  6. Water

    MedlinePlus

    ... Lead Poisoning Prevention Training Center (HHLPPTC) Training Tracks Water Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir For information about lead in water in Flint, MI, please visit http://www.phe. ...

  7. Alkaline chemistry of transuranium elements and technetium and the treatment of alkaline radioactive wastes

    SciTech Connect

    Delegard, C.H.; Peretrukhin, V.F.; Shilov, V.P.; Pikaev, A.K.

    1995-05-01

    Goal of this survey is to generalize the known data on fundamental physical-chemical properties of TRUs and Tc, methods for their isolation, and to provide recommendations that will be useful for partitioning them from alkaline high-level wastes.

  8. Surfactant-enhanced alkaline flooding for light oil recovery. Annual report, 1992--1993

    SciTech Connect

    Wasan, D.T.

    1994-08-01

    In this report, the authors present the results of experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, the authors have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil, and (4) developed a technique to study water-in-oil emulsion film properties.

  9. Promiscuity in alkaline phosphatase superfamily. Unraveling evolution through molecular simulations.

    PubMed

    López-Canut, Violeta; Roca, Maite; Bertrán, Juan; Moliner, Vicent; Tuñón, Iñaki

    2011-08-10

    We here present a theoretical study of the alkaline hydrolysis of a phosphodiester (methyl p-nitrophenyl phosphate or MpNPP) in the active site of Escherichia coli alkaline phosphatase (AP), a monoesterase that also presents promiscuous activity as a diesterase. The analysis of our simulations, carried out by means of molecular dynamics (MD) simulations with hybrid quantum mechanics/molecular mechanics (QM/MM) potentials, shows that the reaction takes place through a D(N)A(N) or dissociative mechanism, the same mechanism employed by AP in the hydrolysis of monoesters. The promiscuous activity observed in this superfamily can be then explained on the basis of a conserved reaction mechanism. According to our simulations the specialization in the hydrolysis of phosphomonoesters or phosphodiesters, developed in different members of the superfamily, is a consequence of the interactions established between the protein and the oxygen atoms of the phosphate group and, in particular, with the oxygen atom that bears the additional alkyl group when the substrate is a diester. A water molecule, belonging to the coordination shell of the Mg(2+) ion, and residue Lys328 seem to play decisive roles stabilizing a phosphomonoester substrate, but the latter contributes to increase the energy barrier for the hydrolysis of phosphodiesters. Then, mutations affecting the nature or positioning of Lys328 lead to an increased diesterase activity in AP. Finally, the capacity of this enzymatic family to catalyze the reaction of phosphoesters having different leaving groups, or substrate promiscuity, is explained by the ability of the enzyme to stabilize different charge distributions in the leaving group using different interactions involving either one of the zinc centers or residues placed on the outer side of the catalytic site.

  10. Response of Desulfovibrio vulgaris to alkaline stress.

    PubMed

    Stolyar, Sergey; He, Qiang; Joachimiak, Marcin P; He, Zhili; Yang, Zamin Koo; Borglin, Sharon E; Joyner, Dominique C; Huang, Katherine; Alm, Eric; Hazen, Terry C; Zhou, Jizhong; Wall, Judy D; Arkin, Adam P; Stahl, David A

    2007-12-01

    The response of exponentially growing Desulfovibrio vulgaris Hildenborough to pH 10 stress was studied using oligonucleotide microarrays and a study set of mutants with genes suggested by microarray data to be involved in the alkaline stress response deleted. The data showed that the response of D. vulgaris to increased pH is generally similar to that of Escherichia coli but is apparently controlled by unique regulatory circuits since the alternative sigma factors (sigma S and sigma E) contributing to this stress response in E. coli appear to be absent in D. vulgaris. Genes previously reported to be up-regulated in E. coli were up-regulated in D. vulgaris; these genes included three ATPase genes and a tryptophan synthase gene. Transcription of chaperone and protease genes (encoding ATP-dependent Clp and La proteases and DnaK) was also elevated in D. vulgaris. As in E. coli, genes involved in flagellum synthesis were down-regulated. The transcriptional data also identified regulators, distinct from sigma S and sigma E, that are likely part of a D. vulgaris Hildenborough-specific stress response system. Characterization of a study set of mutants with genes implicated in alkaline stress response deleted confirmed that there was protective involvement of the sodium/proton antiporter NhaC-2, tryptophanase A, and two putative regulators/histidine kinases (DVU0331 and DVU2580).

  11. Autonomous in situ measurements of seawater alkalinity.

    PubMed

    Spaulding, Reggie S; DeGrandpre, Michael D; Beck, James C; Hart, Robert D; Peterson, Brittany; De Carlo, Eric H; Drupp, Patrick S; Hammar, Terry R

    2014-08-19

    Total alkalinity (AT) is an important parameter for describing the marine inorganic carbon system and understanding the effects of atmospheric CO2 on the oceans. Measurements of AT are limited, however, because of the laborious process of collecting and analyzing samples. In this work we evaluate the performance of an autonomous instrument for high temporal resolution measurements of seawater AT. The Submersible Autonomous Moored Instrument for alkalinity (SAMI-alk) uses a novel tracer monitored titration method where a colorimetric pH indicator quantifies both pH and relative volumes of sample and titrant, circumventing the need for gravimetric or volumetric measurements. The SAMI-alk performance was validated in the laboratory and in situ during two field studies. Overall in situ accuracy was -2.2 ± 13.1 μmol kg(-1) (n = 86), on the basis of comparison to discrete samples. Precision on duplicate analyses of a carbonate standard was ±4.7 μmol kg(-1) (n = 22). This prototype instrument can measure in situ AT hourly for one month, limited by consumption of reagent and standard solutions.

  12. Advanced inorganic separators for alkaline batteries

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W. (Inventor)

    1982-01-01

    A flexible, porous battery separator comprising a coating applied to a porous, flexible substrate is described. The coating comprises: (1) a thermoplastic rubber-based resin which is insoluble and unreactive in the alkaline electrolyte; (2) a polar organic plasticizer which is reactive with the alkaline electrolyte to produce a reaction product which contains a hydroxyl group and/or a carboxylic acid group; and (3) a mixture of polar particulate filler materials which are unreactive with the electrolyte, the mixture comprising at least one first filler material having a surface area of greater than 25 meters sq/gram, at least one second filler material having a surface area of 10 to 25 sq meters/gram, wherein the volume of the mixture of filler materials is less than 45% of the total volume of the fillers and the binder, the filler surface area per gram of binder is about 20 to 60 sq meters/gram, and the amount of plasticizer is sufficient to coat each filler particle. A method of forming the battery separator is also described.

  13. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    SciTech Connect

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  14. The effect of alkaline agents on retention of EOR chemicals

    SciTech Connect

    Lorenz, P.B.

    1991-07-01

    This report summarizes a literature survey on how alkaline agents reduce losses of surfactants and polymers in oil recovery by chemical injection. Data are reviewed for crude sulfonates, clean anionic surfactants, nonionic surfactants, and anionic and nonionic polymers. The role of mineral chemistry is briefly described. Specific effects of various alkaline anions are discussed. Investigations needed to improve the design of alkaline-surfactant-polymer floods are suggested. 62 refs., 28 figs., 6 tabs.

  15. Recovery of phosphorus and nitrogen from alkaline hydrolysis supernatant of excess sludge by magnesium ammonium phosphate.

    PubMed

    Bi, Wei; Li, Yiyong; Hu, Yongyou

    2014-08-01

    Magnesium ammonium phosphate (MAP) method was used to recover orthophosphate (PO₄(3-)-P) and ammonium nitrogen (NH4(+)-N) from the alkaline hydrolysis supernatant of excess sludge. To reduce alkali consumption and decrease the pH of the supernatant, two-stage alkaline hydrolysis process (TSAHP) was designed. The results showed that the release efficiencies of PO₄(3-)-P and NH₄(+)-N were 41.96% and 7.78%, respectively, and the pH of the supernatant was below 10.5 under the running conditions with initial pH of 13, volume ratio (sludge dosage/water dosage) of 1.75 in second-stage alkaline hydrolysis reactor, 20 g/L of sludge concentration in first-stage alkaline hydrolysis reactor. The order of parameters influencing MAP reaction was analyzed and the optimized conditions of MAP reaction were predicted through the response surface methodology. The recovery rates of PO₄(3-)-P and NH₄(+)-N were 46.88% and 16.54%, respectively under the optimized conditions of Mg/P of 1.8, pH 9.7 and reaction time of 15 min.

  16. Basalt as a solid source of calcium and alkalinity for the sequestration of carbon dioxide in building materials

    NASA Astrophysics Data System (ADS)

    Johnson, N. C.; Westfield, I.; Lu, P.; Bourcier, W. L.; Kendall, T.; Constantz, B. R.

    2010-12-01

    Motivated by the idea of converting waste carbon dioxide into usable building products, Calera Corporation has developed a multi-step process that sequesters CO2 as carbonate minerals in cementitious materials. Process inputs include dissolved divalent cations and alkalinity, both of which can be extracted from basalt. In one mode of the Calera process, the electrochemical production of alkalinity generates large volumes of hydrochloric acid as a by-product, which has been shown to effectively leach divalent cations from basalt while being neutralized by the basalt dissolution reaction. Using a 10:1 1M HCl solution to rock ratio, 3500 ppm Ca was extracted while the initial solution was neutralized to a pH of 2.60 in two weeks at a temperature of 80oC in an anoxic batch reactor. In this scenario, mineral carbonation occurs via three steps: electrochemical production of alkalinity, CO2 absorption by the alkaline stream, then precipitation by mixing the basalt-derived divalent cation stream and the CO2-containing alkaline stream. In a second scenario, alkalinity is extracted from basalt using an alkalinity capacitor, a weak acid. This solution may contain a proton source, such as ammonium chloride, or a hydroxyl acceptor, such as boric acid, but the main design constraint is that the pKa of the capacitor be high enough to deprontonate carbonic acid. The weak acid solution is mixed with basalt in an anoxic batch reactor and the dissolving rock consumes protons from the weak acid, generating the conjugate base. The solution rich in conjugate base then absorbs CO2 and the carbonate-rich solution is mixed with a calcium-rich stream to precipitate carbonate minerals. We have extracted up to 1100 mmol alkalinity per kg rock using an alkalinity capacitor, versus no more than 50 mmol alkalinity per kg rock using DI water as a solvent. Again, carbon sequestration occurs via three steps: alkalinity extraction from basalt, CO2 absorption, and finally carbonate precipitation

  17. Carbonic anhydrase 2-like and Na⁺-K⁺-ATPase α gene expression in medaka (Oryzias latipes) under carbonate alkalinity stress.

    PubMed

    Yao, Zongli; Lai, Qifang; Hao, Zhuoran; Chen, Ling; Lin, Tingting; Zhou, Kai; Wang, Hui

    2015-12-01

    High carbonate alkalinity is one of the major stress factors for living organisms in saline-alkaline water areas. Acute and chronic effects of carbonate alkalinity on expression of two genes, carbonic anhydrase 2-like (CA2-like) and Na(+)-K(+)-ATPase α subunit (NKA-α) mRNA in medaka (Oryzias latipes) were evaluated to better understand the responses important for coping with a carbonate alkalinity stress. In the acute exposure experiment, the expression of CA2-like and NKA-α mRNA in the gill and kidney of medaka were examined from 0 h to 7 days exposed to 30.4 mM carbonate alkalinity water. Exposure to high carbonate alkalinity resulted in a transitory alkalosis, followed by a transient increase in gill and kidney CA2-like and NKA-α mRNA expression. In the chronic exposure experiment, the expression of these two genes was examined in the gill and kidney at 50 days post-exposure to six different carbonate alkalinity concentrations ranging from 1.5 to 30.4 mM. Gill and kidney CA2-like mRNA levels in 30.4 mM were approximately 10 and 30 times higher than that of the control (1.5 mM), respectively. Less differences were found in NKA-α expression in the 50-days exposure. The results indicate that when transferred to high carbonate alkalinity water, a transitory alkalosis may occur in medaka, followed by compensatory acid-base and ion regulatory responses. Thus, CA2-like and NKA-α are at least two of the important factors that contribute to the regulation of alkalinity stress.

  18. Solvothermal Synthesis and Formation Mechanism of Potassium Sodium Niobate Mesocrystals Under Low Alkaline Conditions.

    PubMed

    Gu, QiLin; Zhu, Kongjun; Liu, Jinsong; Wang, Jing; Qiu, Jinhao; Cao, Yang; Liu, Pengcheng; Yao, Linlin

    2015-07-01

    Pure-phase (K, Na)NbO3 (KNN) powders with orthorhombic symmetry were successfully synthesized by solvothermal method using isopropanol as solvent, without the addition of water. The as-prepared powders were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry to show the variation of phase, morphology, size distribution and chemical composition under different synthetic conditions, such as fill factors (FF) of the solvothermal system and alkalinity of the starting solution. Compared with the traditional hydrothermal method and the so-called solvothermal method (water aided in fact), small grains with well crystallinity were obtained using 100% isopropanol as reaction medium. The results indicate that both fill factor and alkalinity have significant effects on the phase structure and size distribution of the as-obtained KNN powders. Pure orthorhombic perovskite-structured KNN powders with a grain size of 100 nm were synthesized at the following condition: reaction time, 16 h; reaction temperature, 240 °C; fill factor, 70%; and alkalinity, 1 M. Small grains (~100 nm) tend to form mesocrystals (~10 µm) with tetrakaidecahedron structures, and the possible formation mechanism was proposed. The solvothermal method without the addition of water is a promising alternative to synthesize pure and refined powders under mild reaction conditions.

  19. Tracing the geochemical evolution of alkaline Lake Van, Turkey

    NASA Astrophysics Data System (ADS)

    Kwiecien, Ola; Viehberg, Finn; Plessen, Birgit; Litt, Thomas; Tillman Meyer, Felix

    2015-04-01

    Terminal Lake Van, the world's largest soda basin, is characterised by Na-CO3-Cl water chemistry (Reimer et al., 2008), salinity of ~22 ‰ and high pH of ~9.7. The sedimentary record of the lake goes ca. 600 ka back and documents major climatic events over that period (Stockhecke et al., 2014). Alas, the longevity of the basin does not mean that it persisted unchanged over such a long time. Information collected within the ICDP PALEOVAN project clearly suggests that upon its birth the chemistry of early Lake Van was very different from its modern alkaline equivalent. Here we document, by means of proxy data, the changes in water chemistry in a transforming basin. Results of lithological (Stockhecke et al., 2014) and micropaleontological (ostracod, gastropod and diatom assemblages) analysis, combined with geochemical data (δ18O, δ13C, Mg/Ca, Sr/Ca) obtained from the biogenic and authigenic carbonate fraction imply, that early Lake Van was a relatively shallow, fresh-to-brackish and, most probably, open basin. Sedimentological information points to tectonic factors rather than climatic changes responsible for closing the lake ca. 430 ka ago. Reimer, A., Landmann, G., Kempe, S., 2008. Lake Van, Eastern Anatolia, Hydrochemistry and History. Aquat. Geochemistry 15, 195-222. Stockhecke, M., Sturm, M., Brunner, I., Schmincke, H.-U., Sumita, M., Kipfer, R., Cukur, D., Kwiecien, O., Anselmetti, F.S., 2014. Sedimentary evolution and environmental history of Lake Van (Turkey) over the past 600 000 years. Sedimentology.

  20. Enhancement of accelerated carbonation of alkaline waste residues by ultrasound.

    PubMed

    Araizi, Paris K; Hills, Colin D; Maries, Alan; Gunning, Peter J; Wray, David S

    2016-04-01

    The continuous growth of anthropogenic CO2 emissions into the atmosphere and the disposal of hazardous wastes into landfills present serious economic and environmental issues. Reaction of CO2 with alkaline residues or cementitius materials, known as accelerated carbonation, occurs rapidly under ambient temperature and pressure and is a proven and effective process of sequestering the gas. Moreover, further improvement of the reaction efficiency would increase the amount of CO2 that could be permanently sequestered into solid products. This paper examines the potential of enhancing the accelerated carbonation of air pollution control residues, cement bypass dust and ladle slag by applying ultrasound at various water-to-solid (w/s) ratios. Experimental results showed that application of ultrasound increased the CO2 uptake by up to four times at high w/s ratios, whereas the reactivity at low water content showed little change compared with controls. Upon sonication, the particle size of the waste residues decreased and the amount of calcite precipitates increased. Finally, the sonicated particles exhibited a rounded morphology when observed by scanning electron microscopy.

  1. Longitudinal distributions of dissolved barium, silica and alkalinity in the western and southern Indian Ocean

    NASA Astrophysics Data System (ADS)

    Jeandel, C.; Dupré, B.; Lebaron, G.; Monnin, C.; Minster, J.-F.

    1996-01-01

    Dissolved Ba, Si and alkalinity contents are reported for 11 vertical profiles along a longitudinal section in the western Indian and Southern Oceans, sampled during 1985, 1986 and 1987 in the French expedition INDIGO. Barium concentrations increase from 30 nmol/kg at the surface to 100 nmol/kg at depth in the Southern Ocean. North of the Polar Front, Ba values range from 40 nmol/kg at the surface to 120 nmol/kg in the bottom waters. These vertical variations result from mixing of water masses as well as biologically controlled uptake/regeneration processes. By means of a water-mass mixing model, the non-conservative Ba signal was determined and compared to that of silica. The Δ Ba/Δ Si uptake/regeneration molar ratio is 0.15 × 10 -3 in the south and 0.45 × 10 -3 in the north. In the south, curiously, no release of Ba is observed in Circumpolar Deep Waters, whereas Ba appears to be regenerated in the underlying Antarctic Bottom Waters. Thermodynamic calculations show that Ba is somewhat supersaturated with respect to barite in the upper 3000 m of the southern waters. Thus, whereas surface Ba uptake is probably governed by the biological activity, Ba regeneration in deep waters appears to be controlled by saturation. Barium is correlated linearly with alkalinity at each station, but the slopes of the regression line vary by a factor greater than 2 along the section. The variability of the Δ Ba/Δ Alk ratio between the Southern Ocean and the subtropical and tropical areas raises questions about the validity of applying Δ Ba/Δ Alk values established on a global scale to reconstruct paleo-alkalinity distributions in the Southern Ocean.

  2. Hydrogeochemistry of Lake Turkana, Kenya: Mass balance and mineral reactions in an alkaline lake

    NASA Astrophysics Data System (ADS)

    Yuretich, Richard F.; Cerling, Thure E.

    1983-06-01

    Lake Turkana, in northwestern Kenya, is a closed-basin, alkaline ( pH = 9.2) lake of moderate salinity ( TDS = 2500 ppm). Principal ions are Na +, HCO -3 and CI -. The lake is essentially polymictic in the northern basin and little compositional variation occurs in surface waters. The Omo River is the principal influent, providing some 80-90% of water input to the lake. Chloride has an apparent accumulation time of about 2500 years after accounting for burial of interstitial water. The bottom sediments are predominantly detrital and fine-grained, yet mineral-water reactions are very important for the geochcmical budget. Ca 2+ is precipitated as calcite; Na + is removed as an exchangeable cation on smectite; Mg 2+ is probably incorporated into a Mg-silicate phase, most likely poorlycrystalline smectite, as it enters the lake water; K + may be used in illite regradation. Cation exchange is a very important process in the mass balance of this lake. Over 40% of incoming Na is removed as an exchangeable cation. After cation exchange and interstitial water burial, Na has a response time of 2650 years, which compares favorably with that of chloride. These processes seem to occur rapidly within the water mass of the lake: other reactions may be important in regulating interstitial water compositions. Several changes occur in the upper 3m of sediment: interstitial-water pH drops to 8.3 and alkalinity increases slightly with depth, SO 2-4 decreases slightly, and amorphous silica saturation is approached. These changes are a response to organic matter oxidation and the dissolution of unstable silicates rather than a reversal of reactions occurring in the lake water. High rates of sedimentation (up to 1 cm per year) may minimize the effects of diffusion between the interstitial waters and the lake water, although burial of interstitial water assumes considerable importance.

  3. Development of an alkaline fuel cell subsystem

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A two task program was initiated to develop advanced fuel cell components which could be assembled into an alkaline power section for the Space Station Prototype (SSP) fuel cell subsystem. The first task was to establish a preliminary SSP power section design to be representative of the 200 cell Space Station power section. The second task was to conduct tooling and fabrication trials and fabrication of selected cell stack components. A lightweight, reliable cell stack design suitable for the SSP regenerative fuel cell power plant was completed. The design meets NASA's preliminary requirements for future multikilowatt Space Station missions. Cell stack component fabrication and tooling trials demonstrated cell components of the SSP stack design of the 1.0 sq ft area can be manufactured using techniques and methods previously evaluated and developed.

  4. Properties of cathode materials in alkaline cells

    NASA Astrophysics Data System (ADS)

    Salkind, A. J.; McBreen, J.; Freeman, R.; Parkhurst, W. A.

    1984-04-01

    Conventional and new cathode materials in primary and secondary alkaline cells were investigated for stability, structure, electrochemical reversibility and efficiency. Included were various forms of AgO for reserve type silver zinc batteries, a new material - AgNiO2 and several nickel electrodes for nickel cadmium and nickel hydrogen cells for aerospace applications. A comparative study was made of the stability of electroformed and chemically prepared AgO. Stability was correlated with impurities. After the first discharge AgNiO2 can be recharged to the monovalent level. The discharge product is predominantly silver. Plastic bonded nickel electrodes display a second plateau on discharge. Additions of Co(OH)2 largely eliminate this.

  5. Advanced-capability alkaline fuel cell powerplant

    NASA Astrophysics Data System (ADS)

    Deronck, Henry J.

    The alkaline fuel cell powerplant utilized in the Space Shuttle Orbiter has established an excellent performance and reliability record over the past decade. Recent AFC technology programs have demonstrated significant advances in cell durability and power density. These capabilities provide the basis for substantial improvement of the Orbiter powerplant, enabling new mission applications as well as enhancing performance in the Orbiter. Improved durability would extend the powerplant's time between overhaul fivefold, and permit longer-duration missions. The powerplant would also be a strong candidate for lunar/planetary surface power systems. Higher power capability would enable replacement of the Orbiter's auxiliary power units with electric motors, and benefits mass-critical applications such as the National AeroSpace Plane.

  6. Polyvinyl alcohol membranes as alkaline battery separators

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W.; Gonzalez-Sanabria, O.; Manzo, M. A.

    1982-01-01

    Polyvinly alcohol (PVA) cross-linked with aldehyde reagents yields membranes that demonstrate properties that make them suitable for use as alkaline battery separators. Film properties can be controlled by the choice of cross-linker, cross-link density and the method of cross-linking. Three methods of cross-linking and their effects on film properties are discussed. Film properties can also be modified by using a copolymer of vinyl alcohol and acrylic acid as the base for the separator and cross-linking it similarly to the PVA. Fillers can be incorporated into the films to further modify film properties. Results of separator screening tests and cell tests for several variations of PBA films are discussed.

  7. Rechargeable alkaline manganese dioxide/zinc batteries

    NASA Astrophysics Data System (ADS)

    Kordesh, K.; Weissenbacher, M.

    The rechargeable alkaline manganese dioxide/zinc MnO 2/Zn) system, long established commercial as a primay battery, has reached a high level of performance as a secondary battery system. The operating principles are presented and the technological achievements are surveyed by referencing the recent publications and patent literature. A review is also given of the improvements obtained with newly formulated cathodes and anodes and specially designed batteries. Supported by modelling of the cathode and anode processes and by statistical evidence during cycling of parallel/series-connected modules, the envisioned performance of the next generation of these batteries is described. The possibility of extending the practical use of the improved rechargeable MnO 2/Zn system beyond the field of small electronics into the area of power tools, and even to kW-sized power sources, is demonstrated. Finally, the commercial development in comparison with other rechargeable battery systems is examined.

  8. Inhibition of renal alkaline phosphatase by cimetidine.

    PubMed

    Minai-Tehrani, Dariush; Khodai, Somayeh; Aminnaseri, Somayeh; Minoui, Saeed; Sobhani-Damavadifar, Zahra; Alavi, Sana; Osmani, Raheleh; Ahmadi, Shiva

    2011-08-01

    Alkaline phosphatase (ALP) belongs to hydrolase group of enzymes. It is responsible for removing phosphate groups from many types of molecules, including nucleotides and proteins. Cimetidine (trade name Tagamet) is an antagonist of histamine H2-receptor that inhibits the production of gastric acid. Cimetidine is used for the treatment of gastrointestinal diseases. In this study the inhibitory effect of cimetidine on mouse renal ALP activity was investigated. Our results showed that cimetidine can inhibit ALP by uncompetitive inhibition. In the absence of inhibitor the V(max) and K(m) of the enzyme were found to be 13.7 mmol/mg prot.min and 0.25 mM, respectively. Both the Vmax and Km of the enzyme decreased with increasing cimetidine concentrations (0- 1.2 mM). The Ki and IC(50) of cimetidine were determined to be about 0.5 mM and 0.52 mM, respectively.

  9. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Astrophysics Data System (ADS)

    Swette, Larry; Giner, Jose

    1987-09-01

    Electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells were investigated and developed. The electrocatalysts are defined as the material with a higher activity for the oxygen electrode reaction than the support. Advanced development will require that the materials be prepared in high surface area forms, and may also entail integration of various candidate materials. Eight candidate support materials and seven electrocatalysts were investigated. Of the 8 support, 3 materials meet the preliminary requirements in terms of electrical conductivity and stability. Emphasis is now on preparing in high surface area form and testing under more severe corrosion stress conditions. Of the 7 electrocatalysts prepared and evaluated, at least 5 materials remain as potential candidates. The major emphasis remains on preparation, physical characterization and electrochemical performance testing.

  10. Development of an alkaline fuel cell subsystem

    NASA Astrophysics Data System (ADS)

    1987-03-01

    A two task program was initiated to develop advanced fuel cell components which could be assembled into an alkaline power section for the Space Station Prototype (SSP) fuel cell subsystem. The first task was to establish a preliminary SSP power section design to be representative of the 200 cell Space Station power section. The second task was to conduct tooling and fabrication trials and fabrication of selected cell stack components. A lightweight, reliable cell stack design suitable for the SSP regenerative fuel cell power plant was completed. The design meets NASA's preliminary requirements for future multikilowatt Space Station missions. Cell stack component fabrication and tooling trials demonstrated cell components of the SSP stack design of the 1.0 sq ft area can be manufactured using techniques and methods previously evaluated and developed.

  11. Acylglucuronide in alkaline conditions: migration vs. hydrolysis.

    PubMed

    Di Meo, Florent; Steel, Michele; Nicolas, Picard; Marquet, Pierre; Duroux, Jean-Luc; Trouillas, Patrick

    2013-06-01

    This work rationalizes the glucuronidation process (one of the reactions of the phase II metabolism) for drugs having a carboxylic acid moiety. At this stage, acylglucuronides (AG) metabolites are produced, that have largely been reported in the literature for various drugs (e.g., mycophenolic acid (MPA), diclofenac, ibuprofen, phenylacetic acids). The competition between migration and hydrolysis is rationalized by adequate quantum calculations, combing MP2 and density functional theory (DFT) methods. At the molecular scale, the former process is a real rotation of the drug around the glucuconic acid. This chemical-engine provides four different metabolites with various toxicities. Migration definitely appears feasible under alkaline conditions, making proton release from the OH groups. The latter reaction (hydrolysis) releases the free drug, so the competition is of crucial importance to tackle drug action and elimination. From the theoretical data, both migration and hydrolysis appear kinetically and thermodynamically favored, respectively.

  12. The Alkaline Dissolution Rate of Calcite.

    PubMed

    Colombani, Jean

    2016-07-07

    Due to the widespread presence of calcium carbonate on Earth, several geochemical systems, among which is the global CO2 cycle, are controlled to a large extent by the dissolution and precipitation of this mineral. For this reason, the dissolution of calcite has been thoroughly investigated for decades. Despite this intense activity, a consensual value of the dissolution rate of calcite has not been found yet. We show here that the inconsistency between the reported values stems mainly from the variability of the chemical and hydrodynamic conditions of measurement. The spreading of the values, when compared in identical conditions, is much less than expected and is interpreted in terms of sample surface topography. This analysis leads us to propose benchmark values of the alkaline dissolution rate of calcite compatible with all the published values, and a method to use them in various chemical and hydrodynamic contexts.

  13. Alkaline oxide conversion coatings for aluminum alloys

    SciTech Connect

    Buchheit, R.G.

    1996-02-01

    Three related conversion coating methods are described that are based on film formation which occurs when aluminum alloys are exposed to alkaline Li salt solutions. Representative examples of the processing methods, resulting coating structure, composition and morphology are presented. The corrosion resistance of these coatings to aerated 0.5 M NaCl solution has been evaluated as a function of total processing time using electrochemical impedance spectroscopy (EIS). This evaluation shows that excellent corrosion resistance can be uniformly achieved using no more than 20 minutes of process time for 6061-T6. Using current methods a minimum of 80 minutes of process time is required to get marginally acceptable corrosion resistance for 2024-T3. Longer processing times are required to achieve uniformly good corrosion resistance.

  14. Oxygen electrodes for rechargeable alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry; Giner, Jose

    1987-01-01

    Electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells were investigated and developed. The electrocatalysts are defined as the material with a higher activity for the oxygen electrode reaction than the support. Advanced development will require that the materials be prepared in high surface area forms, and may also entail integration of various candidate materials. Eight candidate support materials and seven electrocatalysts were investigated. Of the 8 support, 3 materials meet the preliminary requirements in terms of electrical conductivity and stability. Emphasis is now on preparing in high surface area form and testing under more severe corrosion stress conditions. Of the 7 electrocatalysts prepared and evaluated, at least 5 materials remain as potential candidates. The major emphasis remains on preparation, physical characterization and electrochemical performance testing.

  15. Alkaline pulping of some eucalypts from Sudan.

    PubMed

    Khristova, P; Kordsachia, O; Patt, R; Dafaalla, S

    2006-03-01

    Four eucalypts (Eucalyptus camaldulensis, Eucalyptus microtheca, Eucalyptus tereticornis and Eucalyptus citriodora) grown in Sudan were examined for their suitability for pulping and papermaking with different alkaline methods. Their physical, morphological and chemical characteristics are reported. The pulping trials with E. citriodora and E. tereticornis were carried out using the kraft-AQ, soda-AQ, modified AS/AQ (ASA), ASAM and kraft methods. For the other two species, only the ASAM and the kraft process were applied. ASAM pulping gave the best results in terms of yield, degree of delignification, mechanical and optical pulp properties. The best pulps, obtained in kraft and ASAM cooking of E. citriodora, were bleached to 88% ISO brightness in a totally chlorine free bleaching sequence (OQ1O/PQ2P). The bleached pulps, especially the ASAM pulp, showed good papermaking properties and would be suitable for manufacture of writing and printing grades of paper.

  16. Postgraduate Symposium: Positive influence of nutritional alkalinity on bone health.

    PubMed

    Wynn, E; Krieg, M A; Lanham-New, S A; Burckhardt, P

    2010-02-01

    patients with an already-high fracture risk. The latter study adds to knowledge by confirming a positive link between dietary alkalinity and bone health indices in the very elderly. In a further study to complement these findings it has also been shown in a group of thirty young women that in Ca sufficiency an acid Ca-rich water has no effect on bone resorption, while an alkaline bicarbonate-rich water leads to a decrease in both serum parathyroid hormone and serum C-telopeptide. Further investigations need to be undertaken to study whether these positive effects on bone loss are maintained over long-term treatment. Mineral-water consumption could be an easy and inexpensive way of helping to prevent osteoporosis and could be of major interest for long-term prevention of bone loss.

  17. Alkaline battery containing a separator of a cross-linked copolymer of vinyl alcohol and unsaturated carboxylic acid

    NASA Technical Reports Server (NTRS)

    Hsu, L. C.; Philipp, W. H.; Sheibley, D. W.; Gonzalez-Sanabria, O. D. (Inventor)

    1985-01-01

    A battery separator for an alkaline battery is described. The separator comprises a cross linked copolymer of vinyl alcohol units and unsaturated carboxylic acid units. The cross linked copolymer is insoluble in water, has excellent zincate diffusion and oxygen gas barrier properties and a low electrical resistivity. Cross linking with a polyaldehyde cross linking agent is preferred.

  18. Soil carbon cycle of different saline and alkaline soils under cotton fields in Tarim River Basin

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoning; Zhao, Chengyi; Stahr, Karl; Kuzyakov, Yakov

    2015-04-01

    Calcium carbonate is the most common form of carbon (C) in semiarid and arid soils. Depending on pH and salinity changes, soils can act as sink or source of atmospheric CO2 as well as contribute to C exchange between CO2 and CaCO3 leading to formation of pedogenic carbonates. However, the rates of these processes and the effects of environmental factors remains unknown. 14CO2 was used to assess carbonate recrystallization in 4 saline and alkaline soils (Aksu alkaline, Aksu saline, Yingbazar alkaline, Yingbazar saline) (EC = 0.32, 1.35, 1.72, 3.67 (1:20) mS cm-1, pH = 8.5, 8.2, 8.9, 7.9 respectively) and to trace the C exchange in the soils of the Tarim River basin depending on CO2 concentrations in soils (0.02%, 0.04%, 0.2%, 0.4% and 4%). 14C was traced in soil water and air as well as in carbonates. The highest 14C in 14CO2 (95% of the 14C input) was observed in Aksu alkaline soil and the highest 14C incorporation in CaCO3 (54%) was observed in Yingbazar saline soil. There were close negative linear relationships between initial CO2 concentrations (0.04%, 0.4% and 4%) and the 14C in Ca14CO3 and in 14CO2. The carbonate recrystallization rate increased with the CO2 concentration and were depended on the recrystalliztion period. The average carbonate recrystallization rate was highest at 4% CO2 concentration for Yingbazar saline soil (6.59×10-4 % per day) and the lowest at 0.04% CO2 concentration for Aksu alkaline soil (0.03×10-4 % per day). The carbonate recrystallization rate linearly increased with the soil EC and with 0.04% and 0.4% CO2 concentration , whereas the carbonate recrystallization rate decreased with pH. The highest CO2 concentration of 4% can 10 to 100 times shorten the full carbonate recrystallization of the remaining primary carbonates compared to lower CO2 concentrations 0.4% and 0.04% for complete (95%) recrystallization of soil carbonate. We conclude that microbial and root respiration affecting CO2 concentration in soil is the most important

  19. Alkaline cleaner replacement for printed wiring board fabrication

    SciTech Connect

    Goldammer, S.E.; Pemberton, S.E.; Tucker, D.R.

    1997-04-01

    A replacement alkaline cleaning chemistry was qualified for the copper cleaning process used to support printed wiring board fabrication. The copper cleaning process was used to prepare copper surfaces for enhancing the adhesion of dry film photopolymers (photoresists and solder masks) and acrylic adhesives. The alkaline chemistry was used to remove organic contaminates such as fingerprints.

  20. Exploring Alkaline Stable Organic Cations for Polymer Hydroxide Exchange Membranes

    DTIC Science & Technology

    2015-04-29

    Organic Cations for Polymer Hydroxide Exchange Membranes Hydroxide exchange membranes (HEMs) are important polymer electrolytes for electrochemical...Exploring Alkaline Stable Organic Cations for Polymer Hydroxide Exchange Membranes Report Title Hydroxide exchange membranes (HEMs) are important polymer ...constructing HEMs. EXPLORING ALKALINE STABLE ORGANIC CATIONS FOR POLYMER HYDROXIDE EXCHANGE MEMBRANES by Bingzi Zhang

  1. The Chemistry of Paper Preservation Part 4. Alkaline Paper.

    ERIC Educational Resources Information Center

    Carter, Henry A.

    1997-01-01

    Discusses the problem of the inherent instability of paper due to the presence of acids that catalyze the hydrolytic degradation of cellulose. Focuses on the chemistry involved in the sizing of both acid and alkaline papers and the types of fillers used. Discusses advantages and problems of alkaline papermaking. Contains 48 references. (JRH)

  2. Removal of plutonium and americium from alkaline waste solutions

    DOEpatents

    Schulz, Wallace W.

    1979-01-01

    High salt content, alkaline waste solutions containing plutonium and americium are contacted with a sodium titanate compound to effect removal of the plutonium and americium from the alkaline waste solution onto the sodium titanate and provide an effluent having a radiation level of less than 10 nCi per gram alpha emitters.

  3. Alkaline stability of quaternary ammonium cations for alkaline fuel cell membranes and ionic liquids.

    PubMed

    Marino, M G; Kreuer, K D

    2015-02-01

    The alkaline stability of 26 different quaternary ammonium groups (QA) is investigated for temperatures up to 160 °C and NaOH concentrations up to 10 mol L(-1) with the aim to provide a basis for the selection of functional groups for hydroxide exchange membranes in alkaline fuel cells and of ionic-liquid cations stable in basic conditions. Most QAs exhibit unexpectedly high alkaline stability with the exception of aromatic cations. β-Protons are found to be far less susceptible to nucleophilic attack than previously suggested, whereas the presence of benzyl groups, nearby hetero-atoms, or other electron-withdrawing species promote degradation reactions significantly. Cyclic QAs proved to be exceptionally stable, with the piperidine-based 6-azonia-spiro[5.5]undecane featuring the highest half-life at the chosen conditions. Absolute and relative stabilities presented herein stand in contrast to literature data, the differences being ascribed to solvent effects on degradation.

  4. Salt- and alkaline-tolerance are linked in Acacia.

    PubMed

    Bui, Elisabeth N; Thornhill, Andrew; Miller, Joseph T

    2014-07-01

    Saline or alkaline soils present a strong stress on plants that together may be even more deleterious than alone. Australia's soils are old and contain large, sometimes overlapping, areas of high salt and alkalinity. Acacia and other Australian plant lineages have evolved in this stressful soil environment and present an opportunity to understand the evolution of salt and alkalinity tolerance. We investigate this evolution by predicting the average soil salinity and pH for 503 Acacia species and mapping the response onto a maximum-likelihood phylogeny. We find that salinity and alkalinity tolerance have evolved repeatedly and often together over 25 Ma of the Acacia radiation in Australia. Geographically restricted species are often tolerant of extreme conditions. Distantly related species are sympatric in the most extreme soil environments, suggesting lack of niche saturation. There is strong evidence that many Acacia have distributions affected by salinity and alkalinity and that preference is lineage specific.

  5. Salt- and alkaline-tolerance are linked in Acacia

    PubMed Central

    Bui, Elisabeth N.; Thornhill, Andrew; Miller, Joseph T.

    2014-01-01

    Saline or alkaline soils present a strong stress on plants that together may be even more deleterious than alone. Australia's soils are old and contain large, sometimes overlapping, areas of high salt and alkalinity. Acacia and other Australian plant lineages have evolved in this stressful soil environment and present an opportunity to understand the evolution of salt and alkalinity tolerance. We investigate this evolution by predicting the average soil salinity and pH for 503 Acacia species and mapping the response onto a maximum-likelihood phylogeny. We find that salinity and alkalinity tolerance have evolved repeatedly and often together over 25 Ma of the Acacia radiation in Australia. Geographically restricted species are often tolerant of extreme conditions. Distantly related species are sympatric in the most extreme soil environments, suggesting lack of niche saturation. There is strong evidence that many Acacia have distributions affected by salinity and alkalinity and that preference is lineage specific. PMID:25079493

  6. Phosphatidylinositol anchor of HeLa cell alkaline phosphatase

    SciTech Connect

    Jemmerson, R.; Low, M.G.

    1987-09-08

    Alkaline phosphatase from cancer cells, HeLa TCRC-1, was biosynthetically labeled with either /sup 3/H-fatty acids or (/sup 3/H)ethanolamine as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography of immunoprecipitated material. Phosphatidylinositol-specific phospholipase C (PI-PLC) released a substantial proportion of the /sup 3/H-fatty acid label from immunoaffinity-purified alkaline phosphatase but had no effect on the radioactivity of (/sup 3/H)ethanolamine-labeled material. PI-PLC also liberated catalytically active alkaline phosphatase from viable cells, and this could be selectively blocked by monoclonal antibodies to alkaline phosphatase. However, the alkaline phosphatase released from /sup 3/H-fatty acid labeled cells by PI-PLC was not radioactive. By contrast, treatment with bromelain removed both the /sup 3/H-fatty acid and the (/sup 3/H)ethanolamine label from purified alkaline phosphatase. Subtilisin was also able to remove the (/sup 3/H)ethanolamine label from the purified alkaline phosphatase. The /sup 3/H radioactivity in alkaline phosphatase purified from (/sup 3/H)ethanolamine-labeled cells comigrated with authentic (/sup 3/H)ethanolamine by anion-exchange chromatography after acid hydrolysis. The data suggest that the /sup 3/H-fatty acid and (/sup 3/H)ethanolamine are covalently attached to the carboxyl-terminal segment since bromelain and subtilisin both release alkaline phosphatase from the membrane by cleavage at that end of the polypeptide chain. The data are consistent with findings for other proteins recently shown to be anchored in the membrane through a glycosylphosphatidylinositol structure and indicate that a similar structure contributes to the membrane anchoring of alkaline phosphatase.

  7. Microbial communities and arsenic biogeochemistry at the outflow of an alkaline sulfide-rich hot spring

    PubMed Central

    Jiang, Zhou; Li, Ping; Van Nostrand, Joy D.; Zhang, Ping; Zhou, Jizhong; Wang, Yanhong; Dai, Xinyue; Zhang, Rui; Jiang, Dawei; Wang, Yanxin

    2016-01-01

    Alkaline sulfide-rich hot springs provide a unique environment for microbial community and arsenic (As) biogeochemistry. In this study, a representative alkaline sulfide-rich hot spring, Zimeiquan in the Tengchong geothermal area, was chosen to study arsenic geochemistry and microbial community using Illumina MiSeq sequencing. Over 0.26 million 16S rRNA sequence reads were obtained from 5-paired parallel water and sediment samples along the hot spring’s outflow channel. High ratios of As(V)/AsSum (total combined arsenate and arsenite concentrations) (0.59–0.78), coupled with high sulfide (up to 5.87 mg/L), were present in the hot spring’s pools, which suggested As(III) oxidation occurred. Along the outflow channel, AsSum increased from 5.45 to 13.86 μmol/L, and the combined sulfide and sulfate concentrations increased from 292.02 to 364.28 μmol/L. These increases were primarily attributed to thioarsenic transformation. Temperature, sulfide, As and dissolved oxygen significantly shaped the microbial communities between not only the pools and downstream samples, but also water and sediment samples. Results implied that the upstream Thermocrinis was responsible for the transformation of thioarsenic to As(III) and the downstream Thermus contributed to derived As(III) oxidation. This study improves our understanding of microbially-mediated As transformation in alkaline sulfide-rich hot springs. PMID:27126380

  8. Study on a novel semidry flue gas desulfurization with multifluid alkaline spray generator

    SciTech Connect

    Zhou, Y.G.; Zhang, M.C.; Wang, D.F.; Wang, L.

    2005-11-09

    The advantages and disadvantages of the typical semidry flue gas desulfurization (FGD) processes are analyzed, and a novel semidry FGD process with multifluid alkaline spray generator is first proposed to improve the colliding contact efficiency between sorbent particles and spray water droplets, and to form a large amount of aqueous lime slurry. The experimental results show that the colliding contact efficiency between lime particles and water droplets in the prefix alkaline spray generator may reach about 70%, which is significantly higher than the colliding contact efficiency of 25% in duct sorbent injection. The SO{sub 2} removal efficiency can reach 64.5% when the Ca/S molar ratio is 1.5, the approach to the saturation temperature is 10.3{sup o}C, and the flue gas residence time is 2.25 s. It is higher than that of in-duct sorbent injection under similar conditions, and the sorbent utilization is improved to 43%. Therefore, the FGD process with a prefix alkaline spray generator can greatly improve SO{sub 2} removal efficiency and sorbent utilization and it will be a new, simple and efficient semidry FGD process for industrial application in the future.

  9. Integrated hydrometallurgical process for production of zinc from electric arc furnace dust in alkaline medium.

    PubMed

    Youcai, Z; Stanforth, R

    2000-12-30

    In this study, a novel and integrated hydrometallurgical process for the production of zinc powder from electric arc furnace (EAF) dust in alkaline medium is reported. The dust is firstly hydrolysed in water, and then fused in caustic soda at 350 degrees C for 1h, followed by leaching in alkaline solution in which both zinc and lead are effectively extracted. Zinc powder is then produced by electrowinning from the leach solution after the lead is selectively removed by precipitation using sodium sulphide as precipitant. The EAF dust tested contained 25% Zn, 1.8% Pb and 33% Fe. It was found that 38% of zinc and 68% of lead could be extracted from the dust when leached directly in caustic soda solution. Leaching of zinc increased to 80% when dust was directly fused with caustic soda followed by alkaline leaching. However, the leaching further increased to 95% when the dust was hydrolysed first with water before fusion. Zinc powder with a purity of 99.95% was then produced by electrowinning from the lead depleted solution. Stainless electrodes were used as both anode and cathode.

  10. Evaluation of the environmental sustainability of farmers' land use decisions in the saline-alkaline areas.

    PubMed

    Yu, Ran; Wang, Jiali

    2015-04-01

    Environmental sustainability has become the focus of agricultural sustainability. This study is aimed at evaluating the environmental sustainability of farmers' land use decisions on saline-alkaline soil in China. Based on empirical and theoretical approaches, the decisions mainly include planting, crop distribution, irrigation, drainage, and fertilization. By surveying 22 administrative villages in typical ecologically fragile saline-alkaline areas of five regions (Shandong, Jiangsu, Jilin, Ningxia, and Xinjiang), the paper builds the evaluation criteria at village level, and obtains a comprehensive index. From the results, irrigation concerns are absent from decision-making. For other decisions, farmers in most villages can appropriately deal with planting, drainage, and fertilization according to the regional natural and social geography conditions. But the comprehensive index of crop distribution in the coastal areas is much stronger than in the northeast and northwest. It is found that the similarities of unsustainability lie in the planting of water-consuming crops, the arbitrary distribution of crops, lack of drainage planning, obsolete water conservancy facilities, excessive use of chemical fertilizers, etc. According to the research, on the one hand, it can guide farmers to rationally make use of saline-alkaline land; on the other hand, it can also provide the basis for government to make differentiated policies in different areas and enhance pertinence in the course of technological extension and application.

  11. Microbial communities and arsenic biogeochemistry at the outflow of an alkaline sulfide-rich hot spring

    NASA Astrophysics Data System (ADS)

    Jiang, Zhou; Li, Ping; van Nostrand, Joy D.; Zhang, Ping; Zhou, Jizhong; Wang, Yanhong; Dai, Xinyue; Zhang, Rui; Jiang, Dawei; Wang, Yanxin

    2016-04-01

    Alkaline sulfide-rich hot springs provide a unique environment for microbial community and arsenic (As) biogeochemistry. In this study, a representative alkaline sulfide-rich hot spring, Zimeiquan in the Tengchong geothermal area, was chosen to study arsenic geochemistry and microbial community using Illumina MiSeq sequencing. Over 0.26 million 16S rRNA sequence reads were obtained from 5-paired parallel water and sediment samples along the hot spring’s outflow channel. High ratios of As(V)/AsSum (total combined arsenate and arsenite concentrations) (0.59-0.78), coupled with high sulfide (up to 5.87 mg/L), were present in the hot spring’s pools, which suggested As(III) oxidation occurred. Along the outflow channel, AsSum increased from 5.45 to 13.86 μmol/L, and the combined sulfide and sulfate concentrations increased from 292.02 to 364.28 μmol/L. These increases were primarily attributed to thioarsenic transformation. Temperature, sulfide, As and dissolved oxygen significantly shaped the microbial communities between not only the pools and downstream samples, but also water and sediment samples. Results implied that the upstream Thermocrinis was responsible for the transformation of thioarsenic to As(III) and the downstream Thermus contributed to derived As(III) oxidation. This study improves our understanding of microbially-mediated As transformation in alkaline sulfide-rich hot springs.

  12. Evidence for alkaline igneous activity and associated metasomatism in the Reelfoot rift, south-central Midcontinent, U. S. A

    SciTech Connect

    Goldhaber, M.B.; Diehl, S.F.; Sutley, S.J. ); Flohr, M.J.K. )

    1993-03-01

    Alkaline igneous magmatism is commonly associated with intracontinental rifts such as the Reelfoot rift (RR). Direct evidence for alkaline magmatism in the area of the RR occurs as lamprophyre and syenite encountered in deep wells. The authors' new studies of lamprophyres and sedimentary rocks from wells in the region provide additional examples of alkaline magmatism and emphasize the effects of related metasomatism. Sedimentary rocks in the Dow Chemical No. 1 Garrigan well, which is not known to contain lamprophyre dikes, probably also were metasomatically altered, as they contain authigenic fluorapatite, Ce-phosphates, and other REE-rich minerals. Enrichments of incompatible and large ion lithophile elements commonly associated with alkaline magmatism occur in the New Madrid test well, near the crest of the Pascola Arch. The carbonate-free fraction of Paleozoic rocks in this well is highly enriched in Nb (500 ppm), Ba (> 5,000 ppm), La (500 ppm), Th (1,000 ppm), and F (2,400 ppm). Abundant inclusion-rich potassium-feldspar cement in a nearby well may also be the result of alkaline metasomatism. Fluorite and elevated F concentrations are found in several wells in the RR, and contrast with stratigraphically correlative platform carbonates of the Ozark uplift, which lack F enrichment. Well and spring water samples above the RR are enriched in fluorine (as much as 5,000 ppb) compared to samples away from the rift which typically have concentrations two orders of magnitude smaller. The data and observations are consistent with relatively widespread alkaline metasomatism, which was associated with the intrusion of alkaline magmas in the RR.

  13. Sedimentary lipid biogeochemistry of an hypereutrophic alkaline lagoon

    SciTech Connect

    Grimalt, J.O.; Albaiges, J. ); Yruela, I.; Saizjimenez, C. ); Toja, J. ); Leeuw, J.W. De. )

    1991-09-01

    A detailed study of the lipid composition of sedimentary and water particulate samples of a dilute alkaline lake (Santa Olalla Lagoon, Guadalquivir Delta, southwestern Spain) has allowed the identification and quantitation of about 300 compounds reflecting predominant inputs of organic matter and very early diagenetic processes. These lipids, dominated by fatty acids (80-86%), account for up to 0.25% wt. of dry sediment which is consistent with the high eutrophic conditions of the lagoon and suggests a good preservation of the originally produced organic matter. However, the primary lipid compounds, mainly from cyanobacterial origin, are strongly modified. The C{sub 30}-C{sub 32}, 1,13- and 1,15-diols constitute the only major group that can be attributed directly to these organisms. The predominant lipids, including the fatty acids, are indicative of intense microbial reworking, namely contributions from gram-positive and gram-negative eubacteria and methanogens. Conversely, the higher plant lipids are better preserved and dominate the aliphatic hydrocarbon fraction. Hydrogenation and dehydration are two major transformation processes in the sedimentary system being reflected in the transformation of sterols into 5{alpha}(H)- and 5{beta}(H)-stanols and sterenes, and 17{beta}(H), 21{beta}(H)-hopan-22-ol into diploptene. Oxidation in the water column seems to involve the partial transformation of sterols into steroid ketones, phytol into 5,9,13-trimethyltetradecanoic acid and two isomeric 3,7,11,15-tetramethyl-17-hexadecanolides, and, possibly, tetrahymanol into gammacer-3-one. Adiantone and bishomohopanoic acid probably result from the partial oxydation of extended polyhydroxyhopanes or the C{sub 30}-C{sub 33} hydroxyhopanes found in the lagoon waters.

  14. Sedimentary lipid biogeochemistry of an hypereutrophic alkaline lagoon

    NASA Astrophysics Data System (ADS)

    Grimalt, J. O.; Yruela, I.; Saiz-Jimenez, C.; Toja, J.; de Leeuw, J. W.; Albaigés, J.

    1991-09-01

    A detailed study of the lipid composition of sedimentary and water particulate samples of a dilute alkaline lake (Santa Olalla Lagoon, Guadalquivir Delta, southwestern Spain) has allowed the identification and quantitation of about 300 compounds reflecting predominant inputs of organic matter and very early diagenetic processes. These lipids, dominated by fatty acids (80-86%), account for up to 0.25% wt. of dry sediment which is consistent with the high eutrophic conditions of the lagoon and suggests a good preservation of the originally produced organic matter. However, the primary lipid compounds, mainly from cyanobacterial origin, are strongly modified. The C30-C32, 1,13- and 1,15-diols constitute the only major group that can be attributed directly to these organisms. The predominant lipids, including the fatty acids, are indicative of intense microbial reworking, namely contributions from gram-positive and gram-negative eubacteria and methanogens. Conversely, the higher plant lipids are better preserved and dominate the aliphatic hydrocarbon fraction. Hydrogenation and dehydration are two major transformation processes in the sedimentary system being reflected in the transformation of sterols into 5α(H)- and 5β(H)-stanols and sterenes, and 17β(H),21β(H)-hopan-22-ol into diploptene. Oxidation in the water column seems to involve the partial transformation of sterols into steroid ketones, phytol into 5,9,13-trimethyltetradecanoic acid and two isomeric 3,7,11,15-tetramethyl-17-hexadecanolides, and, possibly, tetrahymanol into gammacer-3-one. Adiantone and bishomohopanoic acid probably result from the partial oxydation of extended polyhydroxyhopanes or the C30-C33 hydroxyhopanes found in the lagoon waters.

  15. Polyhydroxyflavones as extractants. Communication 7. Solvent extraction of europrium complexes with morin from alkaline media

    SciTech Connect

    Blank, A.B.

    1985-09-01

    This paper studies the analytical application of europium (III)-morin complex which is formed in alkaline medium and has an intense color. The extent of europium extraction was determined by adding to the extract a morin solution in isoamyl alcohol in a 50-100-fold excess with respect to europium. The dependence of the optical density of the extracts on the ph in the system europium (III)-morin-water-organic solvent for different excesses of the reagent is shown: this indicates formation of two extractable complexes, one being dominant in the pH range 4-7, the other at pH greater than or equal to 8.5. The extraction of the europium (III)-morin complex from alkaline solution is used for direct extraction-photometric determination of europium(III) in compounds of elements having amphoteric properties or forming amines (Zns, Mo0/sub 3/).

  16. Effects of inherent alkali and alkaline earth metallic species on biomass pyrolysis at different temperatures.

    PubMed

    Hu, Song; Jiang, Long; Wang, Yi; Su, Sheng; Sun, Lushi; Xu, Boyang; He, Limo; Xiang, Jun

    2015-09-01

    This work aimed to investigate effects of inherent alkali and alkaline earth metallic species (AAEMs) on biomass pyrolysis at different temperatures. The yield of CO, H2 and C2H4 was increased and that of CO2 was suppressed with increasing temperature. Increasing temperature could also promote depolymerization and aromatization reactions of active tars, forming heavier polycyclic aromatic hydrocarbons, leading to decrease of tar yields and species diversity. Diverse performance of inherent AAEMs at different temperatures significantly affected the distribution of pyrolysis products. The presence of inherent AAEMs promoted water-gas shift reaction, and enhanced the yield of H2 and CO2. Additionally, inherent AAEMs not only promoted breakage and decarboxylation/decarbonylation reaction of thermally labile hetero atoms of the tar but also enhanced thermal decomposing of heavier aromatics. Inherent AAEMs could also significantly enhance the decomposition of levoglucosan, and alkaline earth metals showed greater effect than alkali metals.

  17. Effects of bryophytes on succession from alkaline marsh to Sphagnum bog

    SciTech Connect

    Glime, J.M.; Wetzel, R.G.; Kennedy, B.J.

    1982-10-01

    The alkaline eastern marsh of Lawrence Lake, a marl lake in southwestern Michigan, was sampled by randomly placed line transects to determine the bryophyte cover and corresponding vascular plant zones. Cluster analysis indicated three distinct bryophyte zones which correspond with the recognized vascular plant zones. Mosses occupied over 50% of the surface in some areas. Invasion of Sphagnum, vertical zonation of the mosses on hummocks, zonation with distance from the lake, the abundance of non-Sphagnum moss hummocks, and the ability of the non-Sphagnum species to lower the pH of marsh water during laboratory incubations are evidence that non-Sphagnum mosses facilitate succession from alkaline marsh to Sphagnum bog.

  18. IUPAC-NIST Solubility Data Series. 95. Alkaline Earth Carbonates in Aqueous Systems. Part 2. Ca

    SciTech Connect

    De Visscher, Alex; Vanderdeelen, Jan

    2012-06-15

    The alkaline earth carbonates are an important class of minerals. This article is part of a volume in the IUPAC-NIST Solubility Data Series that compiles and critically evaluates solubility data of the alkaline earth carbonates in water and in simple aqueous electrolyte solutions. Part 1 outlined the procedure adopted in this volume, and presented the beryllium and magnesium carbonates. Part 2, the current paper, compiles and critically evaluates the solubility data of calcium carbonate. The chemical forms included are the anhydrous CaCO{sub 3} types calcite, aragonite, and vaterite, the monohydrate monohydrocalcite (CaCO{sub 3}{center_dot} H{sub 2}O), the hexahydrate ikaite (CaCO{sub 3}{center_dot}6H{sub 2}O), and an amorphous form. The data were analyzed with two model variants, and thermodynamic data of each form consistent with each of the models and with the CODATA key values for thermodynamics are presented.

  19. Batteries: from alkaline to zinc-air.

    PubMed

    Dondelinger, Robert M

    2004-01-01

    There is no perfect disposable battery--one that will sit on the shelf for 20 years, then continually provide unlimited current, at a completely constant voltage until exhausted, without producing heat. There is no perfect rechargeable battery--one with all of the above characteristics and will also withstand an infinite overcharge while providing an equally infinite cycle life. There are only compromises. Every battery selection is a compromise between the ideally required characteristics, the advantages, and the limitations of each battery type. General selection of a battery type to power a medical device is largely outside the purview of the biomed. Initially, these are engineering decisions made at the time of medical equipment design and are intended to be followed in perpetuity. However, since newer cell types evolve and the manufacturer's literature is fixed at the time of printing, some intelligent substitutions may be made as long as the biomed understands the characteristics of both the recommended cell and the replacement cell. For example, when the manufacturer recommends alkaline, it is usually because of the almost constant voltage it produces under the devices' design load. Over time, other battery types may be developed that will meet the intent of the manufacturer, at a lower cost, providing longer operational life, at a lower environmental cost, or with a combination of these advantages. In the Obstetrical Doppler cited at the beginning of this article, the user had put in carbon-zinc cells, and the biomed had unknowingly replaced them with carbonzinc cells. If the alkaline cells recommended by the manufacturer had been used, there would have been the proper output voltage at the battery terminals when the [table: see text] cells were at their half-life. Instead, the device refused to operate since the battery voltage was below presumed design voltage. While battery-type substitutions may be easily and relatively successfully made in disposable

  20. Chemical and biotic characteristics of two low-alkalinity lakes in northern Wisconsin: relation to atmospheric deposition

    USGS Publications Warehouse

    Webster, K.E.; Eilers, J.M.; Wiener, J.G.; Glass, G.E.; Garrison, P.J.

    1993-01-01

    Synoptic surveys of water chemistry in north-central Wisconsin documented the presence of many low alkalinity lakes potentially sensitive to acid deposition. Furthermore, lake hydrologic type proved to be a key factor in determining lake sensitivity: the low alkalinity systems were predominately seepage lakes. To test this hypothesis and identify the controls on the chemistry of these low alkalinity systems, the authors initiated hydrologic, chemical, biological and limnological studies at Lakes Clara and Vandercook in 1980. The report summarizes the results of those studies (including previously published hydrologic results) conducted between 1981 and 1983. The major goals are to assess the sensitivity of the study lakes to acid deposition and to identify key processes controlling the acid-base chemistry of these software seepage lakes.

  1. Microbial Thiocyanate Utilization under Highly Alkaline Conditions

    PubMed Central

    Sorokin, Dimitry Y.; Tourova, Tatyana P.; Lysenko, Anatoly M.; Kuenen, J. Gijs

    2001-01-01

    Three kinds of alkaliphilic bacteria able to utilize thiocyanate (CNS−) at pH 10 were found in highly alkaline soda lake sediments and soda soils. The first group included obligate heterotrophs that utilized thiocyanate as a nitrogen source while growing at pH 10 with acetate as carbon and energy sources. Most of the heterotrophic strains were able to oxidize sulfide and thiosulfate to tetrathionate. The second group included obligately autotrophic sulfur-oxidizing alkaliphiles which utilized thiocyanate nitrogen during growth with thiosulfate as the energy source. Genetic analysis demonstrated that both the heterotrophic and autotrophic alkaliphiles that utilized thiocyanate as a nitrogen source were related to the previously described sulfur-oxidizing alkaliphiles belonging to the gamma subdivision of the division Proteobacteria (the Halomonas group for the heterotrophs and the genus Thioalkalivibrio for autotrophs). The third group included obligately autotrophic sulfur-oxidizing alkaliphilic bacteria able to utilize thiocyanate as a sole source of energy. These bacteria could be enriched on mineral medium with thiocyanate at pH 10. Growth with thiocyanate was usually much slower than growth with thiosulfate, although the biomass yield on thiocyanate was higher. Of the four strains isolated, the three vibrio-shaped strains were genetically closely related to the previously described sulfur-oxidizing alkaliphiles belonging to the genus Thioalkalivibrio. The rod-shaped isolate differed from the other isolates by its ability to accumulate large amounts of elemental sulfur inside its cells and by its ability to oxidize carbon disulfide. Despite its low DNA homology with and substantial phenotypic differences from the vibrio-shaped strains, this isolate also belonged to the genus Thioalkalivibrio according to a phylogenetic analysis. The heterotrophic and autotrophic alkaliphiles that grew with thiocyanate as an N source possessed a relatively high level of cyanase

  2. Evaluating Carbonate System Algorithms in a Nearshore System: Does Total Alkalinity Matter?

    PubMed Central

    Sweet, Julia; Brzezinski, Mark A.; McNair, Heather M.; Passow, Uta

    2016-01-01

    Ocean acidification is a threat to many marine organisms, especially those that use calcium carbonate to form their shells and skeletons. The ability to accurately measure the carbonate system is the first step in characterizing the drivers behind this threat. Due to logistical realities, regular carbonate system sampling is not possible in many nearshore ocean habitats, particularly in remote, difficult-to-access locations. The ability to autonomously measure the carbonate system in situ relieves many of the logistical challenges; however, it is not always possible to measure the two required carbonate parameters autonomously. Observed relationships between sea surface salinity and total alkalinity can frequently provide a second carbonate parameter thus allowing for the calculation of the entire carbonate system. Here, we assessed the rigor of estimating total alkalinity from salinity at a depth <15 m by routinely sampling water from a pier in southern California for several carbonate system parameters. Carbonate system parameters based on measured values were compared with those based on estimated TA values. Total alkalinity was not predictable from salinity or from a combination of salinity and temperature at this site. However, dissolved inorganic carbon and the calcium carbonate saturation state of these nearshore surface waters could both be estimated within on average 5% of measured values using measured pH and salinity-derived or regionally averaged total alkalinity. Thus we find that the autonomous measurement of pH and salinity can be used to monitor trends in coastal changes in DIC and saturation state and be a useful method for high-frequency, long-term monitoring of ocean acidification. PMID:27893739

  3. Extracting Vanadium from Stone Coal by a Cyclic Alkaline Leaching Method

    NASA Astrophysics Data System (ADS)

    Hu, Kailong; Liu, Xuheng; Li, Qinggang

    2017-04-01

    In order to achieve an efficient and economical approach on extracting vanadium from stone coal, a cyclic alkaline leaching method was studied in this work. The effects of operating parameters, including the NaOH concentration, temperature, reaction time, and liquid-solid ratio, on vanadium leaching efficiency were investigated. Also, we studied the influence of caustic soda dosage on the cyclic leaching process as well as the effect of increasing ionic strength in leachates and wash water. The results show that this method achieved a 51 pct decrease of the dosage of caustic soda under the optimized conditions compared with the single-step alkaline leaching. The average leaching yield of vanadium reached 82.28 pct. The leachates and wash water in each leaching cycle were utilized for the next leaching cycle, achieving the recycling of alkali as well as waste water. During the cyclic process, the volume of water was not increased, which markedly reduces the discharge of waste water and is also beneficial in terms of cost reduction.

  4. Extracting Vanadium from Stone Coal by a Cyclic Alkaline Leaching Method

    NASA Astrophysics Data System (ADS)

    Hu, Kailong; Liu, Xuheng; Li, Qinggang

    2017-01-01

    In order to achieve an efficient and economical approach on extracting vanadium from stone coal, a cyclic alkaline leaching method was studied in this work. The effects of operating parameters, including the NaOH concentration, temperature, reaction time, and liquid-solid ratio, on vanadium leaching efficiency were investigated. Also, we studied the influence of caustic soda dosage on the cyclic leaching process as well as the effect of increasing ionic strength in leachates and wash water. The results show that this method achieved a 51 pct decrease of the dosage of caustic soda under the optimized conditions compared with the single-step alkaline leaching. The average leaching yield of vanadium reached 82.28 pct. The leachates and wash water in each leaching cycle were utilized for the next leaching cycle, achieving the recycling of alkali as well as waste water. During the cyclic process, the volume of water was not increased, which markedly reduces the discharge of waste water and is also beneficial in terms of cost reduction.

  5. Low pH alkaline chemical formulations

    SciTech Connect

    French, T.R.; Peru, D.A.; Thornton, S.D.

    1989-01-01

    This report describes the development of a surfactant-enhanced alkaline flooding system that is applicable to specific reservoir conditions in Wilmington (California) field. The cost of the chemicals for an ASP (alkali/surfactant/polymer) flood is calculated to be $3.90/bbl of oil produced, with 78% of that cost attributable to polymer. This research included phase behavior tests, oil displacement tests, mineral dissolution tests, and adsorption measurements. It was discovered that consumption of low pH alkalis is low enough in the Wilmington field to be acceptable. In addition, alkali dramatically reduced surfactant adsorption and precipitation. A mixture of NaHCO3 and Na2CO3 was recommended for use as a preflush and in the ASP formulation. Research was also conducted on the synergistic effect that occurs when a mixture of alkali and synthetic surfactant contacts crude oil. It appears that very low IFT is predominantly a result of the activation of the natural surfactants present in the Wilmington oil, and the sustained low IFT is primarily the result of the synthetic surfactant. It also appears that removal of acids from the crude oil by the alkali renders the oil more interfacially reactive to synthetic surfactant. These phenomena help to explain the synergism that results from combining alkali and synthetic surfactant into a single oil recovery formulation. 19 refs., 24 figs., 10 tabs.

  6. Process for treating alkaline wastes for vitrification

    SciTech Connect

    Hsu, Chia-lin W.

    1994-01-01

    According to its major aspects and broadly stated, the present invention is a process for treating alkaline waste materials, including high level radioactive wastes, for vitrification. The process involves adjusting the pH of the wastes with nitric acid, adding formic acid (or a process stream containing formic acid) to reduce mercury compounds to elemental mercury and MnO{sub 2} to the Mn(II) ion, and mixing with class formers to produce a melter feed. The process minimizes production of hydrogen due to noble metal-catalyzed formic acid decomposition during, treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product. An important feature of the present invention is the use of different acidifying and reducing, agents to treat the wastes. The nitric acid acidifies the wastes to improve yield stress and supplies acid for various reactions; then the formic acid reduces mercury compounds to elemental mercury and MnO{sub 2}) to the Mn(II) ion. When the pH of the waste is lower, reduction of mercury compounds and MnO{sub 2}) is faster and less formic acid is needed, and the production of hydrogen caused by catalytically-active noble metals is decreased.

  7. Identification of human pulmonary alkaline phosphatase isoenzymes.

    PubMed

    Capelli, A; Cerutti, C G; Lusuardi, M; Donner, C F

    1997-04-01

    An increase of alkaline phosphatase (ALP) activity has been observed in the bronchoalveolar lavage fluid (BALF) of patients affected by pulmonary fibrosis in chronic interstitial lung disorders. To characterize the ALP isoenzymes in such cases, we used gel filtration, agarose gel electrophoresis, heat and amino acid inhibition assays, wheat-germ agglutinin (WGA) precipitation, and an immunoassay specific for the bone-isoform of ALP. Only one anodic band representing a high-molecular-weight isoform of ALP (Mr approximately 2,000 kDa) was observed on electrophoresis of BALF. The inhibition assay results were consistent for a tissue-nonspecific isoenzyme sensitive to a temperature of 56 degrees C (71.9 +/- 2.5% inhibition) and to homoarginine (65.7 +/- 1.9%), and resistant to L-phenylalanine and L-leucine. Less than 13% of ALP activity was heat-stable. After incubation of BALF specimens with glycosyl-phosphatidylinositol-phospholipase D plus Nonidet P-40, or with phosphatidylinositol-phospholipase C alone, an electrophoretic cathodic band (Mr approximately 220 kDa) appeared near the bone band of a standard serum. With the WGA assay, 84.4 +/- 3.3% of ALP precipitated and the band disappeared. After immunoassay for the bone isoform, a mean of less than 5% enzyme activity was measured. We conclude that the ALP found in BALF is a pulmonary isoform of a tissue nonspecific isoenzyme.

  8. Extracellular alkaline proteinase of Colletotrichum gloeosporioides.

    PubMed

    Dunaevsky, Ya E; Matveeva, A R; Beliakova, G A; Domash, V I; Belozersky, M A

    2007-03-01

    The main proteinase of the filamentous fungus Colletotrichum gloeosporioides causing anthracnoses and serious problems for production and storage of agricultural products has molecular mass of 57 kD and was purified more than 200-fold to homogeneity with the yield of 5%. Maximal activity of the proteinase is at pH 9.0-10.0, and the enzyme is stable at pH 6.0-11.5 (residual activity not less than 70%). The studied enzyme completely kept its activity to 55 degrees C, with a temperature optimum of 45 degrees C. The purified C. gloeosporioides proteinase is stable at alkaline pH values, but rapidly loses its activity at pH values lower than 5.0. Addition of bovine serum albumin stabilizes the enzyme under acidic conditions. Data on inhibitor analysis and substrate specificity of the enzyme allow its classification as a serine proteinase of subtilisin family. It is demonstrated that the extracellular proteinase of C. gloeosporioides specifically effects plant cell wall proteins. It is proposed that the studied proteinase--via hydrolysis of cell wall--provides for penetration of the fungus into the tissues of the host plant.

  9. Production of alkaline protease from Cellulosimicrobium cellulans

    PubMed Central

    Ferracini-Santos, Luciana; Sato, Hélia H

    2009-01-01

    Cellulosimicrobium cellulans is one of the microorganisms that produces a wide variety of yeast cell wall-degrading enzymes, β-1,3-glucanase, protease and chitinase. Dried cells of Saccharomyces cerevisiae were used as carbon and nitrogen source for cell growth and protease production. The medium components KH2PO4, KOH and dried yeast cells showed a significant effect (p<0.05) on the factorial fractional design. A second design was prepared using two factors: pH and percentage of dried yeast cells. The results showed that the culture medium for the maximum production of protease was 0.2 g/l of MgSO4.7H2O, 2.0 g/l of (NH4)2SO4 and 8% of dried yeast cells in 0.15M phosphate buffer at pH 8.0. The maximum alkaline protease production was 7.0 ± 0.27 U/ml over the center point. Crude protease showed best activity at 50ºC and pH 7.0-8.0, and was stable at 50ºC. PMID:24031317

  10. Solubility of pllutonium in alkaline salt solutions

    SciTech Connect

    Hobbs, D.T.; Edwards, T.B.

    1993-02-26

    Plutonium solubility data from several studies have been evaluated. For each data set, a predictive model has been developed where appropriate. In addition, a statistical model and corresponding prediction intervals for plutonium solubility as a quadratic function of the hydroxide concentration have been developed. Because of the wide range of solution compositions, the solubility of plutonium can vary by as much as three orders of magnitude for any given hydroxide concentration and still remain within the prediction interval. Any nuclear safety assessments that depend on the maximum amount of plutonium dissolved in alkaline salt solutions should use concentrations at least as great as the upper prediction limits developed in this study. To increase the confidence in the prediction model, it is recommended that additional solubility tests be conducted at low hydroxide concentrations and with all of the other solution components involved. To validate the model for application to actual waste solutions, it is recommended that the plutonium solubilities in actual waste solutions be determined and compared to the values predicted by the quadratic model.

  11. Process for treating alkaline wastes for vitrification

    DOEpatents

    Hsu, Chia-lin W.

    1995-01-01

    A process for treating alkaline wastes for vitrification. The process involves acidifying the wastes with an oxidizing agent such as nitric acid, then adding formic acid as a reducing agent, and then mixing with glass formers to produce a melter feed. The nitric acid contributes nitrates that act as an oxidant to balance the redox of the melter feed, prevent reduction of certain species to produce conducting metals, and lower the pH of the wastes to a suitable level for melter operation. The formic acid reduces mercury compounds to elemental mercury for removal by steam stripping, and MnO.sub.2 to the Mn(II) ion to prevent foaming of the glass melt. The optimum amounts of nitric acid and formic acid are determined in relation to the composition of the wastes, including the concentrations of mercury (II) and MnO.sub.2, noble metal compounds, nitrates, formates and so forth. The process minimizes the amount of hydrogen generated during treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product.

  12. Process for treating alkaline wastes for vitrification

    DOEpatents

    Hsu, C.L.W.

    1995-07-25

    A process is described for treating alkaline wastes for vitrification. The process involves acidifying the wastes with an oxidizing agent such as nitric acid, then adding formic acid as a reducing agent, and then mixing with glass formers to produce a melter feed. The nitric acid contributes nitrates that act as an oxidant to balance the redox of the melter feed, prevent reduction of certain species to produce conducting metals, and lower the pH of the wastes to a suitable level for melter operation. The formic acid reduces mercury compounds to elemental mercury for removal by steam stripping, and MnO{sub 2} to the Mn(II) ion to prevent foaming of the glass melt. The optimum amounts of nitric acid and formic acid are determined in relation to the composition of the wastes, including the concentrations of mercury (II) and MnO{sub 2}, noble metal compounds, nitrates, formates and so forth. The process minimizes the amount of hydrogen generated during treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product. 4 figs.

  13. Engineering challenges of ocean alkalinity enhancement

    NASA Astrophysics Data System (ADS)

    Kruger, T.; Renforth, P.

    2012-04-01

    The addition of calcium oxide (CaO) to the ocean as a means of enhancing the capacity of the ocean as a carbon sink was first proposed by Haroon Kheshgi in 1995. Calcium oxide is created by heating high purity limestone in a kiln to temperatures of approximately 1000°C. Addition of this material to the ocean draws carbon dioxide out of the atmosphere (approximately 1 tonne of CaO could sequester 1.3 tonnes of CO2). Abiotic carbonate precipitation is inhibited in the surface ocean. This is a carbon and energy expensive process, where approximately 0.8 tonnes of CO2 are produced at a point source for every tonne sequestered. The feasibility of ocean alkalinity enhancement requires capture and storage of the point source of CO2. We present details of a feasibility study of the engineering challenges of Kheshgi's method focusing on the potential scalability and costs of the proposed process. To draw down a PgC per year would require the extraction and processing of ~6Pg of limestone per year, which is similar in scale to the current coal industry. Costs are estimated at ~USD30-40 per tonne of CO2 sequestered through the process, which is favourable to comparative processes. Kheshgi, H. (1995) Energy 20 (9) 915-922

  14. Response of Desulfovibrio vulgaris to Alkaline Stress

    SciTech Connect

    Stolyar, S.; He, Q.; He, Z.; Yang, Z.; Borglin, S.E.; Joyner, D.; Huang, K.; Alm, E.; Hazen, T.C.; Zhou, J.; Wall, J.D.; Arkin, A.P.; Stahl, D.A.

    2007-11-30

    The response of exponentially growing Desulfovibrio vulgarisHildenborough to pH 10 stress was studied using oligonucleotidemicroarrays and a study set of mutants with genes suggested by microarraydata to be involved in the alkaline stress response deleted. The datashowed that the response of D. vulgaris to increased pH is generallysimilar to that of Escherichia coli but is apparently controlled byunique regulatory circuits since the alternative sigma factors (sigma Sand sigma E) contributing to this stress response in E. coli appear to beabsent in D. vulgaris. Genes previously reported to be up-regulated in E.coli were up-regulated in D. vulgaris; these genes included three ATPasegenes and a tryptophan synthase gene. Transcription of chaperone andprotease genes (encoding ATP-dependent Clp and La proteases and DnaK) wasalso elevated in D. vulgaris. As in E. coli, genes involved in flagellumsynthesis were down-regulated. The transcriptional data also identifiedregulators, distinct from sigma S and sigma E, that are likely part of aD. vulgaris Hildenborough-specific stress response system.Characterization of a study set of mutants with genes implicated inalkaline stress response deleted confirmed that there was protectiveinvolvement of the sodium/proton antiporter NhaC-2, tryptophanase A, andtwo putative regulators/histidine kinases (DVU0331 andDVU2580).

  15. Long life expectancy of alkaline fuel cells in hybrid vehicles

    SciTech Connect

    Kordesch, K.; Gsellmann, J.; Aronson, R.R.

    1998-07-01

    The alkaline Hydrogen-Air fuel cell system with circulating KOH-electrolyte and low-cost catalyzed carbon electrodes has a simple design and a good efficiency (high voltage). With new electrodes current densities of 200 to 300 mA/cm 2 are expected with air operation at 80 o C. The Austin A-40 City Car Hybrid vehicle which K. Kordesch operated on public roads for 3 years, demonstrated already in the early 1970s that the useful life of the alkaline system with circulating electrolyte can be increased by completely shutting down the fuel cell part of an AFC-lead-acid battery hybrid system. In this way, only the operating hours during driving time of the vehicle are counting and the electrode deterioration processes going on at open circuit (e.g. carbon oxidation, deep wetting of the electrode interface, parasitic current phenomena, etc.) are reduced. Like with a combustion engine, 3000--4000 actual operating hours are what are required for 200.000 km driving. The stacks, which use low-cost modular cell units, could be replaced after that. Another objective is to lower the fuel cell system cost on a mass production scale to the range of $ 100 to 150 per kW, which is then competitive with car engines, which cost only $ 50 to 75 per kW. No other fuel cell system could even approach such cost estimates. For reasons demanded by space requirements the historic development of AFC's shifted to matrix AFC systems. However, for terrestrial applications the use of circulation systems is more advantageous for thermal and water management. Jet pumps are usable for providing a load-dependent gas circulation. The exchangeability of the KOH makes it possible to operate on air with a less than complete removal of the CO{sub 2}. Cell reversal of series-connected cells, a frequent failure mode during shut-down and starting, is one of the main causes for the short life of electrodes in a high voltage stack. It can be prevented by a parallel, potential providing circuit.

  16. Bacteria associated with deep, alkaline, anaerobic groundwaters in Southeast Washington.

    PubMed

    Stevens, T O; McKinley, J P; Fredrickson, J K

    1993-01-01

    The microbial diversity in two deep, confined aquifers, the Grande Ronde (1270 m) and the Priest Rapids (316 m), Hanford Reservation, Washington, USA, was investigated by sampling from artesian wells. These basaltic aquifers were alkaline (pH 8.5 to 10.5) and anaerobic (Eh -200 to -450 mV). The wells were allowed to free-flow until pH and Eh stabilized, then the microflora was sampled with water filtration and flow-through sandtrap methods. Direct microscopic counts showed 7.6 × 10(5) and 3.6 × 10(3) bacteria ml(-1) in water from the Grande Ronde and Priest Rapids aquifers, respectively. The sand filter method yielded 5.7 × 10(8) and 1.1 × 10(5) cells g(-1) wet weight of sand. The numbers of bacteria did not decrease as increasing volumes of water were flushed out. The heterotrophic diversity of these bacterial populations was assessed using enrichments for 20 functional groups. These groups were defined by their ability to grow in a matrix of five different electron acceptors (O2, Fe(III), NO3 (-), SO4 (2-), HCO3 (-)) and four groups of electron donors (fermentation products, monomers, polymers, aromatics) in a mineral salts medium at pH 9.5. Growth was assessed by protein production. Culture media were subsequently analyzed to determine substrate utilization patterns. Substrate utilization patterns proved to be more reliable indicators of the presence of a particular physiological group than was protein production. The sand-trap method obtained a greater diversity of bacteria than did water filtration, presumably by enriching the proportion of normally sessile bacteria relative to planktonic bacteria. Substrate utilization patterns were different for microflora from the two aquifers and corresponded to their different geochemistries. Activities in the filtered water enrichments more closely matched those predicted by aquifer geochemistry than did the sand-trap enrichments. The greatest activities were found in Fe(III)-reducing enrichments from both wells, SO4

  17. Method of increasing the sulfation capacity of alkaline earth sorbents

    DOEpatents

    Shearer, J.A.; Turner, C.B.; Johnson, I.

    1980-03-13

    A system and method for increasing the sulfation capacity of alkaline earth carbonates to scrub sulfur dioxide produced during the fluidized bed combustion of coal in which partially sulfated alkaline earth carbonates are hydrated in a fluidized bed to crack the sulfate coating and convert the alkaline earth oxide to the hydroxide. Subsequent dehydration of the sulfate-hydroxide to a sulfate-oxide particle produces particles having larger pore size, increased porosity, decreased grain size and additional sulfation capacity. A continuous process is disclosed.

  18. Method of increasing the sulfation capacity of alkaline earth sorbents

    DOEpatents

    Shearer, John A.; Turner, Clarence B.; Johnson, Irving

    1982-01-01

    A system and method for increasing the sulfation capacity of alkaline earth carbonates to scrub sulfur dioxide produced during the fluidized bed combustion of coal in which partially sulfated alkaline earth carbonates are hydrated in a fluidized bed to crack the sulfate coating and convert the alkaline earth oxide to the hydroxide. Subsequent dehydration of the sulfate-hydroxide to a sulfate-oxide particle produces particles having larger pore size, increased porosity, decreased grain size and additional sulfation capacity. A continuous process is disclosed.

  19. Polyvinyl alcohol battery separator containing inert filler. [alkaline batteries

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W.; Hsu, L. C.; Manzo, M. A. (Inventor)

    1981-01-01

    A cross-linked polyvinyl alcohol battery separator is disclosed. A particulate filler, inert to alkaline electrolyte of an alkaline battery, is incorporated in the separator in an amount of 1-20% by weight, based on the weight of the polyvinyl alcohol, and is dispersed throughout the product. Incorporation of the filler enhances performance and increases cycle life of alkaline batteries when compared with batteries containing a similar separator not containing filler. Suitable fillers include titanates, silicates, zirconates, aluminates, wood floor, lignin, and titania. Particle size is not greater than about 50 microns.

  20. Alkali or alkaline earth metal promoted catalyst and a process for methanol synthesis using alkali or alkaline earth metals as promoters

    DOEpatents

    Tierney, John W.; Wender, Irving; Palekar, Vishwesh M.

    1995-01-01

    The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a heterogeneous catalyst comprising reduced copper chromite impregnated with an alkali or alkaline earth metal. There is thus no need to add a separate alkali or alkaline earth compound. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100.degree.-160.degree. C. and the pressure range of 40-65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H.sub.2 /CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

  1. Alkali or alkaline earth metal promoted catalyst and a process for methanol synthesis using alkali or alkaline earth metals as promoters

    DOEpatents

    Tierney, J.W.; Wender, I.; Palekar, V.M.

    1995-01-31

    The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a heterogeneous catalyst comprising reduced copper chromite impregnated with an alkali or alkaline earth metal. There is thus no need to add a separate alkali or alkaline earth compound. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100--160 C and the pressure range of 40--65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H[sub 2]/CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

  2. Alkaline Waterflooding Demonstration Project, Ranger Zone, Long Beach Unit, Wilmington Field, California. Fourth annual report, June 1979-May 1980. Volume 1. Body of report

    SciTech Connect

    Carmichael, J.D.

    1981-03-01

    Comparative core flood testing of preserved Ranger Zone core rock samples was completed; the past year's results were discouraging. In contrast, Ranger sand pack alkaline flood tests gave encouraging results. New insights were gained on in-situ alkaline consumption. Dehydration of sodium orthosilicate water-produced water-crude oil systems does not appear to create any operational problems. The alkaline injection facilities were completed and placed in operation on March 27, 1980. The preflush injection, which was composed of 11.5 million barrels of softened fresh water with an average 0.96% of salt, was completed at that time. The total preflush amounted to approximately 10 pore volume percent. The 0.4% sodium orthosilicate-1.0% salt-soft fresh water injection started at the end of the preflush. A loss of injectivity began at the same time as alkaline injection, which is attributed to divalent ions in the salt brine. Salt was removed temporarily from the system on May 30, 1980. No injection wells were redrilled during the year. Other than plug back of one injector and one producer because of bad liners and repair of one injection well with an inner liner, well work was routine and minor in nature. Dual injection strings were transferred from one well to another. One of the injection wells whose injectivity was damaged by the alkaline-salt injection was successfully stimulated. The pilot was self certified under the tertiary incentive program and cost recoupments obtained. Preparations are underway for making the alkaline flood simulator performance prediction for the pilot. Laboratory testing is actively underway in an attempt to quickly find a remedy for the floc formation that occurs on mixing the salt brine and dilute alkaline solution. Volume 1 describes the activities for this period. Volumes 2 and 3 contain appendices.

  3. Spectroscopic studies of alkaline activated slag geopolymers

    NASA Astrophysics Data System (ADS)

    Mozgawa, W.; Deja, J.

    2009-04-01

    In the work, results of structural studies of different geopolymers, obtained using a granulated blast furnace slag, are presented. The slag was subjected to an alkaline activation process. As activators, NaOH, Na 2CO 3 and liquid glass were applied. IR and NMR spectroscopy were the main experimental methods used, the results obtained were compared with XRD phase analysis and SEM observations. In the IR spectra of raw slag as well as in the spectra of products of paste hydration, the bands due to the characteristic vibrations of bonds observed in both types of oxygen bridges: Si-O-Si and Si-O-Al, were assigned. These bridges constitute basic structural units, forming tetrahedral geopolymer chains. It was found that the slag composition, mainly SiO 2/Al 2O 3 ratio and modification in oxides concentration, influences the presence of the bands connected with the phases (mainly C-S-H) formed during the hydration in the IR spectra. Additionally, significant effect of amorphous phases share on the spectra shape was established. 29Si and 27Al MAS-NMR spectra of initial slag geopolymers and pastes provided information concerning coordination of both atoms in the structures. It was revealed that the kind of slag geopolymers and the conditions of paste hydration influence connectedness of silicooxygen tetrahedra and coordination number of aluminium atoms. Based on IR spectra, it was also possible to determine the influence of the activator type, activation time and hydration conditions on the products formed. Significant changes were observed for the bands assigned to vibrations of carbonate and hydroxide groups. The changes were also noticed in the case of bands due to vibrations of silicate and aluminosilicate bonds.

  4. Alkaline decomposition of synthetic jarosite with arsenic

    PubMed Central

    2013-01-01

    The widespread use of jarosite-type compounds to eliminate impurities in the hydrometallurgical industry is due to their capability to incorporate several elements into their structures. Some of these elements are of environmental importance (Pb2+, Cr6+, As5+, Cd2+, Hg2+). For the present paper, AsO43- was incorporated into the lattice of synthetic jarosite in order to carry out a reactivity study. Alkaline decomposition is characterized by removal of sulfate and potassium ions from the lattice and formation of a gel consisting of iron hydroxides with absorbed arsenate. Decomposition curves show an induction period followed by a conversion period. The induction period is independent of particle size and exponentially decreases with temperature. The conversion period is characterized by formation of a hydroxide halo that surrounds an unreacted jarosite core. During the conversion period in NaOH media for [OH-] > 8 × 10-3 mol L-1, the process showed a reaction order of 1.86, and an apparent activation energy of 60.3 kJ mol-1 was obtained. On the other hand, during the conversion period in Ca(OH)2 media for [OH-] > 1.90 × 10-2 mol L-1, the reaction order was 1.15, and an apparent activation energy of 74.4 kJ mol-1 was obtained. The results are consistent with the spherical particle model with decreasing core and chemical control. PMID:23566061

  5. Alkaline decomposition of synthetic jarosite with arsenic.

    PubMed

    Patiño, Francisco; Flores, Mizraim U; Reyes, Iván A; Reyes, Martín; Hernández, Juan; Rivera, Isauro; Juárez, Julio C

    2013-01-01

    The widespread use of jarosite-type compounds to eliminate impurities in the hydrometallurgical industry is due to their capability to incorporate several elements into their structures. Some of these elements are of environmental importance (Pb(2+), Cr(6+), As(5+), Cd(2+), Hg(2+)). For the present paper, AsO4 (3-) was incorporated into the lattice of synthetic jarosite in order to carry out a reactivity study. Alkaline decomposition is characterized by removal of sulfate and potassium ions from the lattice and formation of a gel consisting of iron hydroxides with absorbed arsenate. Decomposition curves show an induction period followed by a conversion period. The induction period is independent of particle size and exponentially decreases with temperature. The conversion period is characterized by formation of a hydroxide halo that surrounds an unreacted jarosite core. During the conversion period in NaOH media for [OH(-)] > 8 × 10(-3) mol L(-1), the process showed a reaction order of 1.86, and an apparent activation energy of 60.3 kJ mol(-1) was obtained. On the other hand, during the conversion period in Ca(OH)2 media for [OH(-)] > 1.90 × 10(-2) mol L(-1), the reaction order was 1.15, and an apparent activation energy of 74.4 kJ mol(-1) was obtained. The results are consistent with the spherical particle model with decreasing core and chemical control.

  6. Improving the alkaline stability of imidazolium cations by substitution.

    PubMed

    Dong, Huilong; Gu, Fenglou; Li, Min; Lin, Bencai; Si, Zhihong; Hou, Tingjun; Yan, Feng; Lee, Shuit-Tong; Li, Youyong

    2014-10-06

    Imidazolium cations are promising candidates for preparing anion-exchange membranes because of their good alkaline stability. Substitution of imidazolium cations is an efficient way to improve their alkaline stability. By combining density functional theory calculations with experimental results, it is found that the LUMO energy correlates with the alkaline stability of imidazolium cations. The results indicate that alkyl groups are the most suitable substituents for the N3 position of imidazolium cations, and the LUMO energies of alkyl-substituted imidazolium cations depend on the electron-donating effect and the hyperconjugation effect. Comparing 1,2-dimethylimidazolium cations (1,2-DMIm+) and 1,3-dimethylimidazolium cations (1,3-DMIm+) with the same substituents reveals that the hyperconjugation effect is more significant in influencing the LUMO energy of 1,3-DMIms. This investigation reveals that LUMO energy is a helpful aid in predicting the alkaline stability of imidazolium cations.

  7. Regulation of alkaline phosphatase expression in human choriocarcinoma cell lines.

    PubMed Central

    Hamilton, T A; Tin, A W; Sussman, H H

    1979-01-01

    The coincident expression of two structurally distinct isoenzymes of human alkaline phosphatase was demonstrated in two independently derived gestational choriocarcinoma cell lines. These proteins were shown to have enzymatic, antigenic, and physical-chemical properties resembling those of isoenzymes from term placenta and adult liver. The regulation of these isoenzymes has been studied during the exposure of both cell lines to 5-bromodeoxyuridine and dibutyryl cyclic AMP. The responses of the alkaline phosphatase isoenzymes to these agents have also been compared with the response of another protein phenotypic to placenta, the alpha subunit of chorionic gonadotropin. The results show that (i) the separate structural genes coding for placental and liver alkaline phosphatases are regulated in a noncoordinate fashion; (ii) both alkaline phosphatase genes respond independently of the alpha subunit; and (iii) the induction of the placental type isoenzyme occurs via at least two independent pathways. Images PMID:218197

  8. Effects of Different Saline-Alkaline Conditions on the Characteristics of Phytoplankton Communities in the Lakes of Songnen Plain, China

    PubMed Central

    Zang, Shuying; Fan, Yawen; Ye, Huaxiang

    2016-01-01

    Many lakes located in the Songnen Plain of China exhibit a high saline-alkaline level. 25 lakes in the Songnen Plain were selected as research objects in this study. Water samples in these lakes were collected from June to August in 2008. Total Dissolved Solids (TDS) and Total Alkalinity (TA) were measured to assess the saline-alkaline level, and partial canonical correspondence analysis (CCA) was conducted as well. The results show that the majority of these lakes in the study area could be categorized into HCO3−-Na+-I type. According to the TDS assessment, of the total 25 lakes, there are 14 for freshwater, 7 for brackish water and 4 for saltwater; and the respective range of TA was from 0.98 to 40.52. The relationship between TA and TDS indicated significant linear relationship (R2 = 0.9292) in the HCO3−-Na+-I type lakes in the Songnen Plain. There was a general trend that cell density, genera richness and taxonomic diversity decreased with the increase of saline-alkaline gradient, whereas a contrary trend was observed for the proportion of dominant species. When the TDS values were above 3×103mg/L and the TA values were above 15mg/L, there was a significant reduction in cell density, genera richness and biodiversity, and their corresponding values were respectively below 10×106 (ind/L), 15 and approximately 2.5. Through the partial canonical correspondence analysis (CCA), 10.7% of the genera variation was explained by pure saline-alkaline variables. Cyclotella meneghiniana, Melosira ambigua and Melosira granulate were found to become the dominant species in most of these lakes, which indicated that there may be rather wide saline-alkaline niches for common dominant species. About one-quarters of the genera which have certain tolerance to salinity and alkalinity preferred to live in the regions with relatively higher saline-alkaline levels in this study. PMID:27749936

  9. Investigation of the behavior of plutonium(V) in alkaline media

    SciTech Connect

    Budantseva, N.A.; Tananaev, I.G.; Fedoseev, A.M.; Bessonov, A.A.

    1997-09-01

    The stability of the plutonium(V) oxidation state in alkaline media was studied with respect to the neighboring Pu(IV) and Pu(VI) oxidation states. Tests were conducted in 1 M or higher NaOH solutions in the presence and absence of other components of Hanford Site high-level tank waste. Spectrophotometric techniques were found to be effective in studying the behavior of plutonium(V) in alkaline solution at plutonium concentrations above 10{sup -3} M. To this end, plutonium(V) and plutonium(VI) in NaOH were prepared and their spectra characterized. In alkaline solutions with NaOH concentration below 8 M, plutonium(V) was found to be unstable to disproportionation occurring according to the reaction 2 Pu(V)(aq) {yields} Pu(VI)(aq) + Pu(IV)(s). The disproportionation of Pu(V) is complicated by at least two simultaneous processes: (1) the sorption of a significant fraction of the Pu(V) onto the forming Pu(IV) hydrous oxide precipitate, and (2) partial reduction of Pu(VI) by water {alpha}-radiolysis products.

  10. Calixarene crown ether solvent composition and use thereof for extraction of cesium from alkaline waste solutions

    DOEpatents

    Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.; Presley, Derek J.

    2001-01-01

    A solvent composition and corresponding method for extracting cesium (Cs) from aqueous neutral and alkaline solutions containing Cs and perhaps other competing metal ions is described. The method entails contacting an aqueous Cs-containing solution with a solvent consisting of a specific class of lipophilic calix[4]arene-crown ether extractants dissolved in a hydrocarbon-based diluent containing a specific class of alkyl-aromatic ether alcohols as modifiers. The cesium values are subsequently recovered from the extractant, and the solvent subsequently recycled, by contacting the Cs-containing organic solution with an aqueous stripping solution. This combined extraction and stripping method is especially useful as a process for removal of the radionuclide cesium-137 from highly alkaline waste solutions which are also very concentrated in sodium and potassium. No pre-treatment of the waste solution is necessary, and the cesium can be recovered using a safe and inexpensive stripping process using water, dilute (millimolar) acid solutions, or dilute (millimolar) salt solutions. An important application for this invention would be treatment of alkaline nuclear tank wastes. Alternatively, the invention could be applied to decontamination of acidic reprocessing wastes containing cesium-137.

  11. Net alkalinity and net acidity 1: Theoretical considerations

    USGS Publications Warehouse

    Kirby, C.S.; Cravotta, C.A.

    2005-01-01

    Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO2, and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined "CO 2-acidity" is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass- action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mg L -1 as CaCO3 (based on pH and analytical concentrations of dissolved FeII, FeIII, Mn, and Al in mg L -1):aciditycalculated=50{1000(10-pH)+[2(FeII)+3(FeIII)]/56+2(Mn)/ 55+3(Al)/27}underestimates contributions from HSO4- and H+, but overestimates the acidity due to Fe3+ and Al3+. However, these errors tend to approximately cancel each other. It is demonstrated that "net alkalinity" is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation, (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the value obtained in a

  12. Acid transformation of bauxite residue: Conversion of its alkaline characteristics.

    PubMed

    Kong, Xiangfeng; Li, Meng; Xue, Shengguo; Hartley, William; Chen, Chengrong; Wu, Chuan; Li, Xiaofei; Li, Yiwei

    2017-02-15

    Bauxite residue (BR) is a highly alkaline solid hazardous waste produced from bauxite processing for alumina production. Alkaline transformation appears to reduce the environmental risk of bauxite residue disposal areas (BRDAs) whilst potentially providing opportunities for the sustainable reuse and on-going management of BR. Mineral acids, a novel citric acid and a hybrid combination of acid-gypsum treatments were investigated for their potential to reduce residue pH and total alkalinity and transform the alkaline mineral phase. XRD results revealed that with the exception of andradite, the primary alkaline solid phases of cancrinite, grossular and calcite were transformed into discriminative products based on the transformation used. Supernatants separated from BR and transformed bauxite residue (TBR) displayed distinct changes in soluble Na, Ca and Al, and a reduction in pH and total alkalinity. SEM images suggest that mineral acid transformations promote macro-aggregate formation, and the positive promotion of citric acid, confirming the removal or reduction in soluble and exchangeable Na. NEXAFS analysis of Na K-edge revealed that the chemical speciation of Na in TBRs was consistent with BR. Three acid treatments and gypsum combination had no effect on Na speciation, which affects the distribution of Na revealed by sodium STXM imaging.

  13. The alkalinizing effects of metabolizable bases in the healthy calf.

    PubMed Central

    Naylor, J M; Forsyth, G W

    1986-01-01

    The alkalinizing effect of citrate, acetate, propionate, gluconate, L and DL-lactate were compared in healthy neonatal calves. The calves were infused for a 3.5 hour period with 150 mmol/L solutions of the sodium salts of the various bases. Blood pH, base excess, and metabolite concentrations were measured and the responses compared with sodium bicarbonate and sodium chloride infusion. D-gluconate and D-lactate had poor alkalinizing abilities and accumulated in blood during infusion suggesting that they are poorly metabolized by the calf. Acetate, L-lactate and propionate had alkalinizing effects similar to bicarbonate, although those of acetate had a slightly better alkalinizing effect than L-lactate. Acetate was more effectively metabolized because blood acetate concentrations were lower than L-lactate concentrations. There was a tendency for a small improvement in metabolism of acetate and lactate with age. Sodium citrate infusion produced signs of hypocalcemia, presumably because it removed ionized calcium from the circulation. D-gluconate, D-lactate and citrate are unsuitable for use as alkalinizing agents in intravenous fluids. Propionate, acetate and L-lactate are all good alkalinizing agents in healthy calves but will not be as effective in situations where tissue metabolism is impaired. PMID:3024796

  14. Characteristics of plasmalemma alkaline phosphatase of rat mesenteric artery.

    PubMed

    Kwan, C Y

    1983-01-01

    General characteristics of alkaline phosphatase activity of the plasma membrane-enriched fraction isolated from rat mesenteric arteries were investigated. The vascular smooth muscle plasmalemma alkaline phosphatase is a metalloenzyme which is strongly inhibited by chelating agents and this inhibition can be completely overcome by addition of Mg2+ or Ca2+. Zn2+ only partially reactivates the enzyme in the presence of low concentrations of EDTA. The enzymatic hydrolysis of p-nitrophenyl phosphate, beta-glycerophosphate, alpha-glycerophosphate, or 3'-adenosine monophosphate showed an optimal activity in the alkaline region between pH 9 and 11. The alkaline phosphatase activity is distinctly different from the plasmalemma ATPase and 5'-nucleotidase activities with respect to their pH dependence, influence by added divalent metal ions and stability against heat inactivation. Vanadate ion, being structurally similar to the transition state analog of the phosphoryl group, potently inhibits alkaline phosphatase with an apparent Ki of 1.5 microM. The altered alkaline phosphatase activity of vascular smooth muscle in relation to its possible physiological function and pathophysiological manifestation associated with hypertensive disease are discussed.

  15. Overexpression of Human Bone Alkaline Phosphatase in Pichia Pastoris

    NASA Technical Reports Server (NTRS)

    Karr, Laurel; Malone, Christine, C.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    The Pichiapastoris expression system was utilized to produce functionally active human bone alkaline phosphatase in gram quantities. Bone alkaline phosphatase is a key enzyme in bone formation and biomineralization, yet important questions about its structural chemistry and interactions with other cellular enzymes in mineralizing tissues remain unanswered. A soluble form of human bone alkaline phosphatase was constructed by deletion of the 25 amino acid hydrophobic C-terminal region of the encoding cDNA and inserted into the X-33 Pichiapastoris strain. An overexpression system was developed in shake flasks and converted to large-scale fermentation. Alkaline phosphatase was secreted into the medium to a level of 32mgAL when cultured in shake flasks. Enzyme activity was 12U/mg measured by a spectrophotometric assay. Fermentation yielded 880mgAL with enzymatic activity of 968U/mg. Gel electrophoresis analysis indicates that greater than 50% of the total protein in the fermentation is alkaline phosphatase. A purification scheme has been developed using ammonium sulfate precipitation followed by hydrophobic interaction chromatography. We are currently screening crystallization conditions of the purified recombinant protein for subsequent X-ray diffraction analyses. Structural data should provide additional information on the role of alkaline phosphatase in normal bone mineralization and in certain bone mineralization anomalies.

  16. Mechanical properties of untreated and alkaline treated fibers from zalacca midrib wastes

    NASA Astrophysics Data System (ADS)

    Raharjo, Wahyu Purwo; Soenoko, Rudy; Purnowidodo, Anindito; Choiron, Mochammad Agus; Triyono

    2016-03-01

    The environmental concern has been raised due to the abundance of waste from synthetic materials which cannot be biodegraded after their life-time. It provides opportunity to exploit natural resources which are neglected. For example, midrib wastes from zalacca plants after cutting are able to utilize as composite reinforcement. The aim of this research was to characterize the mechanical properties of zalacca midrib fibers. As other ones, zalacca midrib fibers consisted of cellulose, hemicellulose and lignin, which their compositions were 42.54, 34.35 and 28.01 % respectively. To raise their cellulose content, the zalacca fibers were alkaline treated by immersion in the sodium hydroxide for 2 hours and rinsing in the distilled water. The concentration of sodium hydroxide was varied 1 and 5%. To investigate the influence of alkaline treatment, the mechanical testing and morphological analysis was performed. The tensile testing was done to obtain ultimate strength, elastic modulus and strain to fracture. The surface morphology of fibers was observed by SEM. The average ultimate tensile strength of zalacca fibers ranged from 182.12 MPa (untreated) to 417.94 MPa (5%NaOH treated). The diameter measurement showed that the alkaline treatment reduce the average fiber diameters due to the decline of the hemicellulose and lignin content as fiber matrix. This caused the increase of the tensile strength and elastic modulus due to the reduction of diameters as divider meanwhile the cellulose content as structural supporter of the fibers was relatively constant. From the SEM analysis, it was shown that the alkaline treatment reduced the fiber matrix so that its surface morphology became rougher due to the microfibrils appearance.

  17. An alkaline spring system within the Del Puerto ophiolite (California USA): A Mars analog site

    SciTech Connect

    Blank, J.G.; Green, S.; Blake, D.; Valley, J.; Kita, N.; Treiman, A.; Dobson, P.F.

    2008-10-01

    Mars appears to have experienced little compositional differentiation of primitive lithosphere, and thus much of the surface of Mars is covered by mafic lavas. On Earth, mafic and ultramafic rocks present in ophiolites, oceanic crust and upper mantle that have been obducted onto land, are therefore good analogs for Mars. The characteristic mineralogy, aqueous geochemistry, and microbial communities of cold-water alkaline springs associated with these mafic and ultramafic rocks represent a particularly compelling analog for potential life-bearing systems. Serpentinization, the reaction of water with mafic minerals such as olivine and pyroxene, yields fluids with unusual chemistry (Mg-OH and Ca-OH waters with pH values up to {approx}12), as well as heat and hydrogen gas that can sustain subsurface, chemosynthetic ecosystems. The recent observation of seeps from pole-facing crater and canyon walls in the higher Martian latitudes supports the hypothesis that even present conditions might allow for a rockhosted chemosynthetic biosphere in near-surface regions of the Martian crust. The generation of methane within a zone of active serpentinization, through either abiogenic or biogenic processes, could account for the presence of methane detected in the Martian atmosphere. For all of these reasons, studies of terrestrial alkaline springs associated with mafic and ultramafic rocks are particularly timely. This study focuses on the alkaline Adobe Springs, emanating from mafic and ultramafic rocks of the California Coast Range, where a community of novel bacteria is associated with the precipitation of Mg-Ca carbonate cements. The carbonates may serve as a biosignature that could be used in the search for evidence of life on Mars.

  18. Towards high conductivity in anion-exchange membranes for alkaline fuel cells.

    PubMed

    Li, Nanwen; Guiver, Michael D; Binder, Wolfgang H

    2013-08-01

    Quaternized poly(2,6-dimethylphenylene oxide) materials (PPOs) containing clicked 1,2,3-triazoles were first prepared through Cu(I) -catalyzed "click chemistry" to improve the anion transport in anion-exchange membranes (AEMs). Clicked 1,2,3-triazoles incorporated into AEMs provided more sites to form efficient and continuous hydrogen-bond networks between the water/hydroxide and the triazole for anion transport. Higher water uptake was observed for these triazole membranes. Thus, the membranes showed an impressive enhancement of the hydroxide diffusion coefficient and, therefore, the anion conductivities. The recorded hydroxide conductivity was 27.8-62 mS cm(-1) at 20 °C in water, which was several times higher than that of a typical PPO-based AEM (TMA-20) derived from trimethylamine (5 mS cm(-1) ). Even at reduced relative humidity, the clicked membrane showed superior conductivity to a trimethylamine-based membrane. Moreover, similar alkaline stabilities at 80 °C in 1 M NaOH were observed for the clicked and non-clicked membranes. The performance of a H2 /O2 single cell assembled with a clicked AEM was much improved compared to that of a non-clicked TMA-20 membrane. The peak power density achieved for an alkaline fuel cell with the synthesized membrane 1a(20) was 188.7 mW cm(-2) at 50 °C. These results indicated that clicked AEM could be a viable strategy for improving the performance of alkaline fuel cells.

  19. Coral calcification under environmental change: a direct comparison of the alkalinity anomaly and buoyant weight techniques

    NASA Astrophysics Data System (ADS)

    Schoepf, Verena; Hu, Xinping; Holcomb, Michael; Cai, Wei-Jun; Li, Qian; Wang, Yongchen; Xu, Hui; Warner, Mark E.; Melman, Todd F.; Hoadley, Kenneth D.; Pettay, D. Tye; Matsui, Yohei; Baumann, Justin H.; Grottoli, Andréa G.

    2017-03-01

    Two primary methods—the buoyant weight (BW) and alkalinity anomaly (AA) techniques—are currently used to quantify net calcification rates ( G) in scleractinian corals. However, it remains unclear whether they are directly comparable since the few method comparisons conducted to date have produced inconsistent results. Further, such a comparison has not been made for tropical corals. We directly compared G BW and G AA in four tropical and one temperate coral species cultured under various pCO2, temperature, and nutrient conditions. A range of protocols for conducting alkalinity depletion incubations was assessed. For the tropical corals, open-top incubations with manual stirring produced G AA that were highly correlated with and not significantly different from G BW. Similarly, G AA of the temperate coral was not significantly different from G BW when incubations provided water motion using a pump, but were significantly lower than G BW by 16% when water motion was primarily created by aeration. This shows that the two techniques can produce comparable calcification rates in corals but only when alkalinity depletion incubations are conducted under specific conditions. General recommendations for incubation protocols are made, especially regarding adequate water motion and incubation times. Further, the re-analysis of published data highlights the importance of using appropriate regression statistics when both variables are random and measured with error. Overall, we recommend the AA technique for investigations of community and short-term day versus night calcification, and the BW technique to measure organism calcification rates integrated over longer timescales due to practical limitations of both methods. Our findings will facilitate the direct comparison of studies measuring coral calcification using either method and thus have important implications for the fields of ocean acidification research and coral biology in general.

  20. Bioaccumulation of perfluoroalkyl substances by Daphnia magna in water with different types and concentrations of protein.

    PubMed

    Xia, Xinghui; Rabearisoa, Andry H; Jiang, Xiaoman; Dai, Zhineng

    2013-10-01

    Perfluoroalkyl substances (PFASs) are sometimes regarded as proteinophilic compounds, however, there is no research report about the effect of environmental protein on the bioaccumulation of PFASs in waters. In the present study we investigated influences of protein on the bioaccumulation of six kinds of PFASs by Daphnia magna in water; it included perfluorooctane sulfonate, perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, and perfluorododecanoic acid. Two types of protein including bovine albumin from animal and soy peptone from plant were compared and the effects of protein concentration were investigated. Both types of protein at high concentrations (10 and 20 mg L(-1)) suppressed the bioaccumulation of PFASs. When protein concentration increased from 0 to 20 mg L(-1), the decreasing ratios of the PFAS body burden (35.3-52.9%) in Daphnia magna induced by bovine albumin were significantly higher than those (22.0-36.6%) by soy peptone. The dialysis bag experiment results showed that the binding of PFASs to protein followed the Freundlich isotherm, suggesting it is not a linear partitioning process but an adsorption-like process. The partition coefficients of PFASs between bovine albumin and water were higher compared to soy peptone; this resulted in higher reducing rates of freely dissolved concentrations of PFASs with increasing bovine albumin concentration, leading to a stronger suppression of PFAS bioaccumulation. However, the presence of both types of protein with a low concentration (1 mg L(-1)) enhanced the bioaccumulation of PFASs. Furthermore, the water-based bioaccumulation factor based on the freely dissolved concentrations of PFASs even increased with and the depuration rate constants of PFASs from Daphnia magna decreased with protein concentration, suggesting that protein would not only reduce the bioavailable concentrations and uptake rates of PFASs but also lower the elimination rates of PFASs in

  1. Quantitation of Alkaline Phosphatase Isoenzymes Using Agarose Containing Wheat Germ Lectin

    DTIC Science & Technology

    1989-07-01

    SIl Quantitation of Alkaline Phosphatase Isoenzymes Using Agarose Containing Wheat Germ Lectin A thesis submitted in partial fulfillment of the...16 Wheat Germ Lectin Electrophoresis to Quantitate Alkaline Phosphatase Isoenzymes ................ 16 Alkaline Phosphatase Isoenzyme...vs Polyacrylamide Gel Electrophoresis ......................... 40 Clinical Correlation Using Wheat Germ Lectin 45 Placental Alkaline Phosphatase

  2. Physicochemical Properties of Defatted Rambutan (Nephelium lappaceum) Seed Flour after Alkaline Treatment.

    PubMed

    Eiamwat, Jirawat; Wanlapa, Sorada; Kampruengdet, Sukit

    2016-03-31

    Rambutan seeds were subjected to SC-CO₂ extraction at 35 MPa, 45 °C to obtain defatted rambutan seed flour. Its physicochemical properties before and after treatment with alkali solution using 0.075 N NaOH were investigated. Alkali-treated flour had a significant increment in bulk density, swelling power, water adsorption capacity, emulsion capacity and stability but a reduction in turbidity, solubility and oil absorption capacity. Pasting measurements showed peak viscosity, breakdown, setback and final viscosity increased significantly for the alkali-treated flour, while pasting temperature decreased. The alkaline treatment decreased the least gelation concentration, but increased the apparent viscosity.

  3. A self-humidifying acidic-alkaline bipolar membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Peng, Sikan; Xu, Xin; Lu, Shanfu; Sui, Pang-Chieh; Djilali, Ned; Xiang, Yan

    2015-12-01

    To maintain membrane hydration and operate effectively, polymer electrolyte membrane fuel cells (PEMFCs) require elaborate water management, which significantly increases the complexity and cost of the fuel cell system. Here we propose a novel and entirely different approach to membrane hydration by exploiting the concept of bipolar membranes. Bipolar membrane (BPM) fuel cells utilize a composite membrane consisting of an acidic polymer electrolyte membrane on the anode side and an alkaline electrolyte membrane on the cathode side. We present a novel membrane electrode assembly (MEA) fabrication method and demonstrate experimentally and theoretically that BPM fuel cells can (a) self-humidify to ensure high ionic conductivity; and (b) allow use of non-platinum catalysts due to inherently faster oxygen reduction kinetics on an alkaline cathode. Our Pt-based BPM fuel cell achieves a two orders of magnitude gain in power density of 327 mW cm-2 at 323 K under dry gas feed, the highest power output achieved under anhydrous operation conditions. A theoretical analysis and in situ measurements are presented to characterize the unique interfacial water generation and transport behavior that make self-humidification possible during operation. Further optimization of these features and advances in fabricating bipolar MEAs would open the way for a new generation of self-humidifying and water-management-free PEMFCs.

  4. Differences in the chemical composition of Enterococcus faecalis biofilm under conditions of starvation and alkalinity.

    PubMed

    Chen, Weixu; Liang, Jingping; He, Zhiyan; Jiang, Wei

    2017-01-02

    ABSTACT This study aimed to investigate the dynamic changes that occur in the chemical composition of an Enterococcus faecalis (E. faecalis) biofilm under conditions of starvation and in an alkaline environment and to explore the function of chemical composition changes in the resistance of the E. faecalis biofilm to an extreme environment. This study established an in vitro E. faecalis biofilm model under starvation and in an alkaline environment. During the formation of the biofilm, the pH value and nutritional condition of the culture medium were changed, and the changes in chemical composition were observed using biochemical measures. The results showed that, when the pH value of the culture medium was 11, the percentage of water-insoluble polysaccharides in the biofilm was significantly lower than under other conditions. In addition, the percentage of water-soluble polysaccharides in culture medium with pH values of 9 and 11 gradually decreased. The level of the water-soluble polysaccharides in each milligram of dry weight of biofilm at pH 11 increased compared to that under other conditions. The results from this study indicate that the chemical composition of E. faecalis biofilm changed in extreme environments. These changes served as a defensive mechanism for E. faecalis against environmental pressures.

  5. Alkalinity Enrichment Enhances Net Calcification of a Coral Reef Flat

    NASA Astrophysics Data System (ADS)

    Albright, R.; Caldeira, K.

    2015-12-01

    Ocean acidification is projected to shift reefs from a state of net accretion to one of net dissolution sometime this century. While retrospective studies show large-scale changes in coral calcification over the last several decades, it is not possible to unequivocally link these results to ocean acidification due to confounding factors of temperature and other environmental parameters. Here, we quantified the calcification response of a coral reef flat to alkalinity enrichment to test whether reef calcification increases when ocean chemistry is restored to near pre-industrial conditions. We used sodium hydroxide (NaOH) to increase the total alkalinity of seawater flowing over a reef flat, with the aim of increasing carbonate ion concentrations [CO32-] and the aragonite saturation state (Ωarag) to values that would have been attained under pre-industrial atmospheric pCO2 levels. We developed a dual tracer regression method to estimate alkalinity uptake (i.e., calcification) in response to alkalinity enrichment. This approach uses the change in ratios between a non-conservative tracer (alkalinity) and a conservative tracer (a non-reactive dye, Rhodamine WT) to assess the fraction of added alkalinity that is taken up by the reef as a result of an induced increase in calcification rate. Using this method, we estimate that an average of 17.3% ± 2.3% of the added alkalinity was taken up by the reef community. In providing results from the first seawater chemistry manipulation experiment performed on a natural coral reef community (without artificial confinement), we demonstrate that, upon increase of [CO32-] and Ωarag to near pre-industrial values, reef calcification increases. Thus, we conclude that, the impacts of ocean acidification are already being felt by coral reefs. This work is the culmination of years of work in the Caldeira lab at the Carnegie Institution for Science, involving many people including Jack Silverman, Kenny Schneider, and Jana Maclaren.

  6. Functional interrelationships in the alkaline phosphatase superfamily: phosphodiesterase activity of Escherichia coli alkaline phosphatase.

    PubMed

    O'Brien, P J; Herschlag, D

    2001-05-15

    Escherichia coli alkaline phosphatase (AP) is a proficient phosphomonoesterase with two Zn(2+) ions in its active site. Sequence homology suggests a distant evolutionary relationship between AP and alkaline phosphodiesterase/nucleotide pyrophosphatase, with conservation of the catalytic metal ions. Furthermore, many other phosphodiesterases, although not evolutionarily related, have a similar active site configuration of divalent metal ions in their active sites. These observations led us to test whether AP could also catalyze the hydrolysis of phosphate diesters. The results described herein demonstrate that AP does have phosphodiesterase activity: the phosphatase and phosphodiesterase activities copurify over several steps; inorganic phosphate, a strong competitive inhibitor of AP, inhibits the phosphodiesterase and phosphatase activities with the same inhibition constant; a point mutation that weakens phosphate binding to AP correspondingly weakens phosphate inhibition of the phosphodiesterase activity; and mutation of active site residues substantially reduces both the mono- and diesterase activities. AP accelerates the rate of phosphate diester hydrolysis by 10(11)-fold relative to the rate of the uncatalyzed reaction [(k(cat)/K(m))/k(w)]. Although this rate enhancement is substantial, it is at least 10(6)-fold less than the rate enhancement for AP-catalyzed phosphate monoester hydrolysis. Mutational analysis suggests that common active site features contribute to hydrolysis of both phosphate monoesters and phosphate diesters. However, mutation of the active site arginine to serine, R166S, decreases the monoesterase activity but not the diesterase activity, suggesting that the interaction of this arginine with the nonbridging oxygen(s) of the phosphate monoester substrate provides a substantial amount of the preferential hydrolysis of phosphate monoesters. The observation of phosphodiesterase activity extends the previous observation that AP has a low level of

  7. Crystal structure of rat intestinal alkaline phosphatase--role of crown domain in mammalian alkaline phosphatases.

    PubMed

    Ghosh, Kaushik; Mazumder Tagore, Debarati; Anumula, Rushith; Lakshmaiah, Basanth; Kumar, P P B S; Singaram, Senthuran; Matan, Thangavelu; Kallipatti, Sanjith; Selvam, Sabariya; Krishnamurthy, Prasad; Ramarao, Manjunath

    2013-11-01

    Intestinal alkaline phosphatases (IAPs) are involved in the cleavage of phosphate prodrugs to liberate the drug for absorption in the intestine. To facilitate in vitro characterization of phosphate prodrugs, we have cloned, expressed, purified and characterized IAPs from rat and cynomolgus monkey (rIAP and cIAP respectively) which are important pre-clinical species for drug metabolism studies. The recombinant rat and monkey enzymes expressed in Sf9 insect cells (IAP-Ic) were found to be glycosylated and active. Expression of rat IAP in Escherichia coli (rIAP-Ec) led to ~200-fold loss of activity that was partially recovered by the addition of external Zn(2+) and Mg(2+) ions. Crystal structures of rIAP-Ec and rIAP-Ic were determined and they provide rationale for the discrepancy in enzyme activities. Rat IAP-Ic retains its activity in presence of both Zn(2+) and Mg(2+) whereas activity of most other alkaline phosphatases (APs) including the cIAP was strongly inhibited by excess Zn(2+). Based on our crystal structure, we hypothesized the residue Q317 in rIAP, present within 7 Å of the Mg(2+) at M3, to be important for this difference in activity. The Q317H rIAP and H317Q cIAP mutants showed reversal in effect of Zn(2+), corroborating the hypothesis. Further analysis of the two structures indicated a close linkage between glycosylation and crown domain stability. A triple mutant of rIAP, where all the three putative N-linked glycosylation sites were mutated showed thermal instability and reduced activity.

  8. Martian alkaline basites chemically resemble basic rocks of the Lovozero alkaline massif, Kola peninsula

    NASA Astrophysics Data System (ADS)

    Kochemasov, G.

    The comparative wave planetology [1, 5] successfully overcomes the most principal martian test having now analyses of alkaline rocks from Columbia Hills [2, 3, 4]. This kind of rocks was predicted earlier on basis of the wave paradigm having stated that "the higher planetary relief range - the higher density difference between lithologies composing hypsometrically (tectonically) contrasting blocks [5]. This paradigm declares that "celestial bodies are dichotomic"(Theorem 1), "celestial bodies are sectoral" (Theorem 2), "celestial bodies are granular"(Theorem 3), "angular momenta of different level blocks tend to be equal" (Theorem 4)[1, 5]. Mars is a typical terrestrial planet but the farthest from Sun and thus with the smallest tide effects. Nevertheless it has the highest relief range and seems to be most distorted (ellipsoid in shape) and broken by deep fissures. The wave approach explains this by a warping action of standing waves of 4 ortho- and diagonal directions - they are the longest and highest in the martian case. These interfering warping waves caused by the elliptic keplerian orbits implying periodically changing accelerations and inertia-gravity forces produce inevitable tectonic dichotomy (the fundamental wave 1 long 2πR), sectoring (wave 2, πR, and other overtones), granulation. A granule size depends on an orbital frequency: the higher frequency the smaller granule. The Earth's granule, as a scale, is πR/4 (see it in NASA's PIA04159), Venus ` πR/6, Mercury's πR/16, Mars' πR/2 (the sizes are strictly tied to orb. fr.). Along with the granule sizes increase relief ranges ( Mercury ˜5 km, Venus 14, Earth 20, Mars ˜30) and compositional (density) difference between lowland and highland lithologies [5]. The lowland compositions become Fericher and denser: enstatite (Mercury), Mg-basalt (Venus), tholeiite (Earth), Fe-basalt (Mars). The highland compositions get less dense, lighter: anorthosite, alkaline basalt, andesite and conditional "albitite

  9. On the complex structural diffusion of proton holes in nanoconfined alkaline solutions within slit pores

    PubMed Central

    Muñoz-Santiburcio, Daniel; Marx, Dominik

    2016-01-01

    The hydroxide anion OH−(aq) in homogeneous bulk water, that is, the solvated proton hole, is known to feature peculiar properties compared with excess protons solvated therein. In this work, it is disclosed that nanoconfinement of such alkaline aqueous solutions strongly affects the key structural and dynamical properties of OH−(aq) compared with the bulk limit. The combined effect of the preferred hypercoordinated solvation pattern of OH−(aq), its preferred perpendicular orientation relative to the confining surfaces, the pronounced layering of nanoconfined water and the topology of the hydrogen bond network required for proton hole transfer lead to major changes of the charge transport mechanism, in such a way that the proton hole migration mechanism depends exquisitely on the width of the confined space that hosts the water film. Moreover, the anionic Zundel complex, which is of transient nature in homogeneous bulk solutions, can be dynamically trapped as a shallow intermediate species by suitable nanoconfinement conditions. PMID:27550616

  10. Escherichia coli alkaline phosphatase. Kinetic studies with the tetrameric enzyme.

    PubMed

    Halford, S E; Schlesinger, M J; Gutfreund, H

    1972-03-01

    1. The stability of the tetrameric form of Escherichia coli alkaline phosphatase was examined by analytical ultracentrifugation. 2. The stopped-flow technique was used to study the hydrolysis of nitrophenyl phosphates by the alkaline phosphatase tetramer at pH7.5 and 8.3. In both cases transient product formation was observed before the steady state was attained. Both transients consisted of the liberation of 1mol of nitrophenol/2mol of enzyme subunits within the dead-time of the apparatus. The steady-state rates were identical with those observed with the dimer under the same conditions. 3. The binding of 2-hydroxy-5-nitrobenzyl phosphonate to the alkaline phosphatase tetramer was studied by the temperature-jump technique. The self-association of two dimers to form the tetramer is linked to a conformation change within the dimer. This accounts for the differences between the transient phases in the reactions of the dimer and the tetramer with substrate. 4. Addition of P(i) to the alkaline phosphatase tetramer caused it to dissociate into dimers. The tetramer is unable to bind this ligand. It is suggested that the tetramer undergoes a compulsory dissociation before the completion of its first turnover with substrate. 5. On the basis of these findings a mechanism is proposed for the involvement of the alkaline phosphatase tetramer in the physiology of E. coli.

  11. Characterization of Human Bone Alkaline Phosphatase in Pichia Pastoris

    NASA Technical Reports Server (NTRS)

    Malone, Christine C.; Ciszak, Eva; Karr, Laurel J.

    1999-01-01

    A soluble form of human bone alkaline phosphatase has been expressed in a recombinant strain of the methylotrophic yeast Pichia pastoris. We constructed a plasmid containing cDNA encoding for human bone alkaline phosphatase, with the hydrophobic carboxyl terminal portion deleted. Alkaline phosphatase was secreted into the medium to a level of 32mg/L when cultured in shake flasks, and enzyme activity was 12U/mg, as measured by a spectrophotometric assay. By conversion to a fermentation system, a yield of 880mg/L has been achieved with an enzyme activity of 968U/mg. By gel electrophoresis analysis, it appears that greater than 50% of the total protein in the fermentation media is alkaline phosphatase. Although purification procedures are not yet completely optimized, they are expected to include filtration, ion exchange and affinity chromatography. Our presentation will focus on the purification and crystallization results up to the time of the conference. Structural data should provide additional information on the role of alkaline phosphatase in normal bone mineralization and in certain bone mineralization anomalies.

  12. Interannual sedimentary effluxes of alkalinity in the southern North Sea: Model results compared with summer observations.

    NASA Astrophysics Data System (ADS)

    Paetsch, Johannes; Kuehn, Wilfried; Six, Katharina

    2016-04-01

    Alkalinity generation in the sediment of the southern North Sea is the focus of several recent studies. One motivation for these efforts is the potentially enhanced buffering capacity of anthropogenic CO2 invasion into the corresponding pelagic system. An adaptation of a global multilayer sediment model (Heinze et al., 1999) in combination with a pelagic ecosystem model for shelf sea dynamics was used to study the benthic reactions on very different annual cycles (2001 - 2009) including the River Elbe summer flooding in 2002. The focus of this study is the efflux of alkalinity, their different contributors (aerobic respiration, denitrification, net sulfate reduction, calcite dissolution, nitrification) and their seasonal and interannual cycles. Similar to the observations covering the southern North Sea (Brenner et al., 2015) the model results show large horizontal gradients from the near-shore high productive areas with benthic remineralization up to Rmin = 10.6 mol C m-2 yr-1 and TA generation RTA = 2 mol C m-2 yr-1 to off-shore moderate productive areas with mean Rmin = 2.5 mol C m-2 yr-1 and mean TA generation RTA = 0.4 mol C m-2 yr-1. Beside calcite dissolution, aerobic respiration (producing ammonium) and denitrification are the largest contributors to alkalinity generation. Nitrification is reducing alkalinity in the sediment. Due to low regenerated primary production in summer, the year 2001 exhibits the lowest input of particulate organic matter into the sediment (POCexp=2.3 mol C m-2 yr-1), while the year 2003 exhibits the highest export production (POCexp=2.6 mol C m-2 yr-1). The biogeochemical reactions and the effluxes from the sediment follow these pelagic amplitudes with a time lag of about one year with damped amplitudes. References Brenner, H., Braeckman, U., Le Guitton, M., Meysman, F.J.R., 2015. The impact of sedimentary alkalinity release on the water column CO2 system in the North Sea. Biogeosiences Discussion, 12(15): 12395-12453. Heinze, C

  13. Cellulose nanocrystal-based composite electrolyte with superior dimensional stability for alkaline fuel cell membranes

    DOE PAGES

    Lu, Yuan; Artmentrout, Aaron A.; Li, Juchuan; ...

    2015-01-01

    Cellulose nanocrystal (CNC)-based composite films were prepared as a solid electrolyte for alkaline fuel cells. Poly (vinyl alcohol) (PVA) and silica gel hybrid was used to bind the CNCs to form a robust composite film. The mass ratio (i.e., 1 : 1, 1 : 2) of PVA and silica gel was tuned to control the hydrophobicity of the resulting films. Composite films with a range of CNC content (i.e., 20 to 60%) were prepared to demonstrate the impact of CNC on the performance of these materials as a solid electrolyte for alkaline fuel cells. Different from previously reported cross-linked polymermore » films, CNC-based composite films with 40% hydrophobic binder (i.e., PVA : silica gel=1 : 2) exhibited simultaneous low water swelling (e.g., ~5%) and high water uptake (e.g., ~80%) due to the hydrophilicity and extraordinary dimensional stability of CNC. It also showed a conductivity of 0.044 and 0.065 S/cm at 20 and 60 oC, respectively. To the best of our knowledge, the film with 60% CNC and 40% binder is characterized by the lowest hydroxide conductivity-normalized swelling ratio. Decreased CNC content (i.e., 40 and 20%) resulted in comparable hydroxide conductivity but a greater swelling ratio. These results demonstrate the advantage of CNC as a key component for a solid electrolyte for alkaline fuel cells over conventional polymers, suggesting the great potential of CNCs in improving the dimensional stability while maintaining the conductivity of existing anion exchange membranes.« less

  14. Post-prandial metabolic alkalosis in the seawater-acclimated trout: the alkaline tide comes in.

    PubMed

    Bucking, Carol; Fitzpatrick, John L; Nadella, Sunita R; Wood, Chris M

    2009-07-01

    The consequences of feeding and digestion on acid-base balance and regulation in a marine teleost (seawater-acclimated steelhead trout; Oncorhynchus mykiss) were investigated by tracking changes in blood pH and [HCO3-], as well as alterations in net acid or base excretion to the water following feeding. Additionally the role of the intestine in the regulation of acid-base balance during feeding was investigated with an in vitro gut sac technique. Feeding did not affect plasma glucose or urea concentrations, however, total plasma ammonia rose during feeding, peaking between 3 and 24 h following the ingestion of a meal, three-fold above resting control values (approximately 300 micromol ml(-1)). This increase in plasma ammonia was accompanied by an increase in net ammonia flux to the water (approximately twofold higher in fed fish versus unfed fish). The arterial blood also became alkaline with increases in pH and plasma [HCO3-] between 3 and 12 h following feeding, representing the first measurement of an alkaline tide in a marine teleost. There was no evidence of respiratory compensation for the measured metabolic alkalosis, as Pa CO2 remained unchanged throughout the post-feeding period. However, in contrast to an earlier study on freshwater-acclimated trout, fed fish did not exhibit a compensating increase in net base excretion, but rather took in additional base from the external seawater, amounting to approximately 8490 micromol kg(-1) over 48 h. In vitro experiments suggest that at least a portion of the alkaline tide was eliminated through increased HCO3- secretion coupled to Cl- absorption in the intestinal tract. This did not occur in the intestine of freshwater-acclimated trout. The marked effects of the external salinity (seawater versus freshwater) on different post-feeding patterns of acid-base balance are discussed.

  15. Surfactant-enhanced alkaline flooding for light oil recovery. Quarterly report, January 1--March 31, 1994

    SciTech Connect

    Wasan, D.T.

    1994-06-01

    The overall objective of this project is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultra-low tension. In addition, the novel concept of pH gradient design to optimize flood water conditions will be tested. Last quarter we investigated the phase behavior and the regions where in the middle phase occurs. The optimum phase was found to go through a maximum with pH, sodium concentration and surfactant concentration. The optimum pH is about 12.0 to 13.5, the optimum sodium concentration is about 0.513 mol/liter, and the optimum surfactant concentration is about 0.2%. The effect of surfactant type was also investigated. Petrostep B-105 was found to give the most middle phase production. This quarter, we investigated the contact angle of Long Beach oil, Adena oil, and a model oil on a solid glass surface in contact with an aqueous alkaline solution both with and without added preformed surfactant. The contact angle with Long Beach and Adena oils showed oil-wet conditions, whereas the model oil showed both oil-wet and water-wet conditions depending on the pH of the aqueous phase. The addition of surfactant to the alkaline solution resulted in making the system less oil-wet. Spreading of the oil on the glass surface was observed in all three systems investigated.

  16. Cellulose nanocrystal-based composite electrolyte with superior dimensional stability for alkaline fuel cell membranes

    SciTech Connect

    Lu, Yuan; Artmentrout, Aaron A.; Li, Juchuan; Tekinalp, Halil L.; Nanda, Jagjit; Ozcan, Soydan

    2015-01-01

    Cellulose nanocrystal (CNC)-based composite films were prepared as a solid electrolyte for alkaline fuel cells. Poly (vinyl alcohol) (PVA) and silica gel hybrid was used to bind the CNCs to form a robust composite film. The mass ratio (i.e., 1 : 1, 1 : 2) of PVA and silica gel was tuned to control the hydrophobicity of the resulting films. Composite films with a range of CNC content (i.e., 20 to 60%) were prepared to demonstrate the impact of CNC on the performance of these materials as a solid electrolyte for alkaline fuel cells. Different from previously reported cross-linked polymer films, CNC-based composite films with 40% hydrophobic binder (i.e., PVA : silica gel=1 : 2) exhibited simultaneous low water swelling (e.g., ~5%) and high water uptake (e.g., ~80%) due to the hydrophilicity and extraordinary dimensional stability of CNC. It also showed a conductivity of 0.044 and 0.065 S/cm at 20 and 60 oC, respectively. To the best of our knowledge, the film with 60% CNC and 40% binder is characterized by the lowest hydroxide conductivity-normalized swelling ratio. Decreased CNC content (i.e., 40 and 20%) resulted in comparable hydroxide conductivity but a greater swelling ratio. These results demonstrate the advantage of CNC as a key component for a solid electrolyte for alkaline fuel cells over conventional polymers, suggesting the great potential of CNCs in improving the dimensional stability while maintaining the conductivity of existing anion exchange membranes.

  17. Improving electrochemical methods of producing hydrogen in alkaline media via ammonia and urea electrolysis

    NASA Astrophysics Data System (ADS)

    Boggs, Bryan Kenneth

    Theoretically, ammonia electrolysis consumes 95% less energy than its major competitor water electrolysis and offers an economical, environmental, and efficient means for reducing nitrate contaminations in ground and drinking water. Thermodynamically at standard conditions, ammonia electrolysis consumes 1.55 Wh to produce one gram of hydrogen. This same gram of hydrogen generates 33 Wh utilizing a proton exchange membrane fuel cell (PEMFC). There is a potential of 31.45 Wh of net energy when coupling an ammonia electrolytic cell (AEC) and a PEMFC. Considering that PEMFCs are 60% efficient, the actual energy output ranges between 18 and 20 Wh. Prior to the research shown here, ammonia electrolysis in alkaline media was requiring more than 20 Wh of energy input due to slow anode kinetics and poor electrochemical cell design thus making any chances of a self-sustaining energy generator unfeasible. This research focused on improving and optimizing anode electrocatalyst materials, electrode configurations, and cell designs, as well as demonstrating stationary and mobile applications of ammonia electrolysis. In addition to ammonia electrolysis, a novel electrochemical technique, urea electrolysis in alkaline media, was created and investigated. Similar to ammonia electrolysis, the anodic reaction, which is the oxidation of urea, was found to be the most rate-limiting half-cell reaction and required improvement. This research focused on fundamentally understanding the mechanism of urea electrolysis as well as investigating common electrocatalysts for small organic molecules. As a result, urea electrolysis in alkaline media proved to be a direct, economical, and environmental approach to producing hydrogen electrochemically with an inexpensive transition metal.

  18. Sulfate reduction controlled by organic matter availability in deep sediment cores from the saline, alkaline Lake Van (Eastern Anatolia, Turkey)

    PubMed Central

    Glombitza, Clemens; Stockhecke, Mona; Schubert, Carsten J.; Vetter, Alexandra; Kallmeyer, Jens

    2013-01-01

    As part of the International Continental Drilling Program deep lake drilling project PaleoVan, we investigated sulfate reduction (SR) in deep sediment cores of the saline, alkaline (salinity 21.4‰, alkalinity 155 m mEq-1, pH 9.81) Lake Van, Turkey. The cores were retrieved in the Northern Basin (NB) and at Ahlat Ridge (AR) and reached a maximum depth of 220 m. Additionally, 65–75 cm long gravity cores were taken at both sites. SR rates (SRR) were low (≤22 nmol cm-3 day-1) compared to lakes with higher salinity and alkalinity, indicating that salinity and alkalinity are not limiting SR in Lake Van. Both sites differ significantly in rates and depth distribution of SR. In NB, SRR are up to 10 times higher than at AR. SR could be detected down to 19 mblf (meters below lake floor) at NB and down to 13 mblf at AR. Although SRR were lower at AR than at NB, organic matter (OM) concentrations were higher. In contrast, dissolved OM in the pore water at AR contained more macromolecular OM and less low molecular weight OM. We thus suggest, that OM content alone cannot be used to infer microbial activity at Lake Van but that quality of OM has an important impact as well. These differences suggest that biogeochemical processes in lacustrine sediments are reacting very sensitively to small variations in geological, physical, or chemical parameters over relatively short distances. PMID:23908647

  19. Surfactant-enhanced alkaline flooding for light oil recovery. Quarterly report, April 1, 1995--June 30, 1995

    SciTech Connect

    Wasan, D.T.

    1995-09-01

    The overall objective of this project is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultra-low tension. In addition, the novel concept of pH gradient design to optimize flood water conditions will be tested.

  20. Rare-earth-doped bifunctional alkaline-earth metal fluoride nanocrystals via a facile microwave-assisted process.

    PubMed

    Pang, Min; Liu, Dapeng; Lei, Yongqian; Song, Shuyan; Feng, Jing; Fan, Weiqiang; Zhang, Hongjie

    2011-06-20

    Rare-earth-doped magnetic-optic bifunctional alkaline-earth metal fluoride nanocrystals have been successfully synthesized via a facile microwave-assisted process. The as-prepared nanocrystals were monodisperse and could form stable colloidal solutions in polar solvents, such as water and ethanol. They show bright-green fluorescence emisson. Furthermore, Gd(3+)-doped ones exhibit paramagnetic behavior at room temperature and superparamagnetic behavior at 2 K.

  1. Alkaline direct alcohol fuel cells using an anion exchange membrane

    NASA Astrophysics Data System (ADS)

    Matsuoka, Koji; Iriyama, Yasutoshi; Abe, Takeshi; Matsuoka, Masao; Ogumi, Zempachi

    Alkaline direct alcohol fuel cells using an OH-form anion exchange membrane and polyhydric alcohols were studied. A high open circuit voltage of ca. 800 mV was obtained for a cell using Pt-Ru/C (anode) and Pt/C (cathode) at 323 K, which was about 100-200 mV higher than that for a DMFC using Nafion ®. The maximum power densities were in the order of ethylene glycol > glycerol > methanol > erythritol > xylitol. Silver catalysts were used as a cathode catalyst to fabricate alkaline fuel cells, since silver catalyst is almost inactive in the oxidation of polyhydric alcohols. Alkaline direct ethylene glycol fuel cells using silver as a cathode catalyst gave excellent performance because higher concentrations of fuel could be supplied to the anode.

  2. Alkaline Comet Assay for Assessing DNA Damage in Individual Cells.

    PubMed

    Pu, Xinzhu; Wang, Zemin; Klaunig, James E

    2015-08-06

    Single-cell gel electrophoresis, commonly called a comet assay, is a simple and sensitive method for assessing DNA damage at the single-cell level. It is an important technique in genetic toxicological studies. The comet assay performed under alkaline conditions (pH >13) is considered the optimal version for identifying agents with genotoxic activity. The alkaline comet assay is capable of detecting DNA double-strand breaks, single-strand breaks, alkali-labile sites, DNA-DNA/DNA-protein cross-linking, and incomplete excision repair sites. The inclusion of digestion of lesion-specific DNA repair enzymes in the procedure allows the detection of various DNA base alterations, such as oxidative base damage. This unit describes alkaline comet assay procedures for assessing DNA strand breaks and oxidative base alterations. These methods can be applied in a variety of cells from in vitro and in vivo experiments, as well as human studies.

  3. Metasomatized lithosphere and the origin of alkaline lavas.

    PubMed

    Pilet, Sébastien; Baker, Michael B; Stolper, Edward M

    2008-05-16

    Recycled oceanic crust, with or without sediment, is often invoked as a source component of continental and oceanic alkaline magmas to account for their trace-element and isotopic characteristics. Alternatively, these features have been attributed to sources containing veined, metasomatized lithosphere. In melting experiments on natural amphibole-rich veins at 1.5 gigapascals, we found that partial melts of metasomatic veins can reproduce key major- and trace-element features of oceanic and continental alkaline magmas. Moreover, experiments with hornblendite plus lherzolite showed that reaction of melts of amphibole-rich veins with surrounding lherzolite can explain observed compositional trends from nephelinites to alkali olivine basalts. We conclude that melting of metasomatized lithosphere is a viable alternative to models of alkaline basalt formation by melting of recycled oceanic crust with or without sediment.

  4. Surfactant-enhanced alkaline flooding for light oil recovery. [Quarterly] report, March 31--June 30, 1993

    SciTech Connect

    Wasan, D.T.

    1993-09-01

    The overall objective of this project is to develop a very cost- effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultra-low tension. In addition, the novel concept of pH gradient design to optimize flood water conditions will be tested. Last quarter we have investigated the mechanisms responsible for spontaneous emulsification in alkali/acidic crude oil systems with and without added surfactant. We have observed that the roll cell size and formation time depend strongly on the pH and ionic strength of the alkaline solution. For a particular roll cell size, the addition of surfactant causes the cells to take longer to form, causing an interfacial resistance to mass transfer and making the interface more rigid. We have shown that interfacial turbulence is a necessary but not sufficient condition for spontaneous emulsification. Low interfacial tension is also a necessary condition. This quarter a microwave interferometric procedure was developed for the determination of low water content (0. 5 to 10 vol%) of water-in-oil macroemulsions. The apparatus operates at a frequency of 23.48 GHz in the K-band microwave region. The procedure is based on the large differences in dielectric properties between water and oil, and it utilizes the variation in phase shift as sample path length is varied. Measurements are accurate to within 0.5 vol% water.

  5. Alkaline direct transesterification of different species of Stichococcus for bio-oil production.

    PubMed

    Gargano, Immacolata; Marotta, Raffaele; Andreozzi, Roberto; Olivieri, Giuseppe; Marzocchella, Antonio; Spasiano, Danilo; Pinto, Gabriele; Pollio, Antonino

    2016-12-25

    The cost of bio-oil refining from microalgal biomass can be significantly reduced by combining extraction and transesterification. The characterisation and optimisation of the combined steps have been carried out on strains of Stichococcus bacillaris, focusing on catalyst type and concentration, reaction time and temperature, methanol/biomass ratio, pre-mixing time and water content in the biomass. The bio-oil yield has been referenced as production of fatty acid methyl esters (FAMEs). The maximum yield (∼17%) was achieved using dried biomass with alkaline catalyst at 60°C and methanol/biomass weight ratio of 79:1. Alkaline catalyst conditions gave faster reaction rates and higher bio-oil yields than acid catalyst. Yield was also strongly affected by water content in the biomass. A mechanistic interpretation has been proposed to elucidate the effect of the different operating conditions. However, the structural characteristics of the Chlorophyta cell wall can be very different, leading to different bio-oil yields when the same protocol is applied. Therefore, the optimised protocol of direct transesterification for Stichococcus bacillaris strains was tested on other Stichococcus strains and several other Chlorophyta species characterised by a different cell wall structure. It was clearly demonstrated that different results for bio-oil yield were obtained within the same microalgal species and much more within different microalgal genera.

  6. Occurrence and activity of iron- and sulfur-oxidizing microorganisms in alkaline coal strip mine spoils.

    PubMed

    Olson, G J; McFeters, G A; Temple, K L

    1981-03-01

    Spoils samples collected from a coal strip mine in southeastern Montana were examined for populations and activities of iron- and sulfur-oxidizing bacteria. Spoils examined were of three types: (a) acidic pyrite-rich waste coal, (b) oxidation halo material, and (c) alkaline material, which was the most widespread type. Bacterial numbers, sulfur oxidation, and(14)CO2 uptake activity declined to low levels in the summer when spoils were dry. Even in wetter spring months pyritic spoils contained relatively low numbers of acidophilic iron- and sulfur-oxidizing bacteria, probably indicative of water stress since the same spoils incubated with excess water or dilute mineral salts showed considerably greater bacterial numbers and activity. Certain wells in coal and spoils aquifers contained substantial populations of iron-oxidizing acidophilic bacteria. However, these wells were always of alkaline or neutral pH, indicating that bacterial pyrite oxidation occurred where groundwaters contacted either replaced spoils or coal that contained pyrite or other metal sulfides. Bacterial activity may contribute to trace metal and sulfate leaching in the area.

  7. Surfactant-enhanced alkaline flooding for light oil recovery. Final report 1994--1995

    SciTech Connect

    Wasan, D.T.

    1995-12-01

    In this report, the authors present the results of their experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, the authors have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil, and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are summarized.

  8. Surfactant-enhanced alkaline flooding for light oil recovery. Final report

    SciTech Connect

    Wasan, D.T.

    1996-05-01

    In this report, we present the results of our experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12. 0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, we have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are discussed.

  9. Characterization of Laboratory Prepared Concrete Pastes Exposed to High Alkaline and High Sodium Salt Solutions

    SciTech Connect

    Langton, C. A.

    2016-06-30

    The objective of this study was to identify potential chemical degradation mechanisms for the Saltstone Disposal Unit (SDU) concretes, which over the performance life of the structures may be exposed to highly alkaline sodium salt solutions containing sulfate, hydroxide, and other potentially corrosive chemicals in salt solution and saltstone flush water, drain water, leachate and / or pore solution. The samples analyzed in this study were cement pastes prepared in the SIMCO Technologies, Inc. concrete laboratory. They were based on the paste fractions of the concretes used to construct the Saltstone Disposal Units (SDUs). SDU 1 and 4 concrete pastes were represented by the PV1 test specimens. The paste in the SDU 2, 3, 5, and 6 concrete was represented by the PV2 test specimens. SIMCO Technologies, Inc. selected the chemicals and proportions in the aggressive solutions to approximate proportions in the saltstone pore solution [2, 3, 5, and 6]. These test specimens were cured for 56 days in curing chamber before being immersed in aggressive solutions. After exposure, the samples were frozen to prevent additional chemical transport and reaction. Selected archived (retrieved from the freezer) samples were sent to the Savannah River National Laboratory (SRNL) for additional characterization using x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray (EDX) spectroscopy. Characterization results are summarized in this report. In addition, a correlation between the oxide composition of the pastes and their chemical durability in the alkaline salt solutions is provided.

  10. Crystallization Pressures of Alkaline Magmas of the Kula Volcanic Province, Western Turkey

    NASA Astrophysics Data System (ADS)

    Solpuker, U.; Kilinc, A. I.

    2013-12-01

    PProducts of Quaternary sodic alkaline volcanism in western Anatolia is mainly observed around Kula region. The Kula Volcanic Province experienced three episodes of alkaline volcanism. We used the MELTS algorithm to model the evolution path of the Kula magmas by imposing fractional crystallization as a constraint and retrieved the initial system pressure using clinopyroxene geobarometer. We showed that the use of clinopyroxene geobarometer and the MELTS algorithm in combination can be used to estimate the initial water content of magma and the oxygen fugacity of the system. Pressure estimates for the most of the clinopyroxenes are between 12 to 7 kbar. The estimated crystallization temperatures decrease from the first episode to the third episode. The first episode magmas crystallized around Moho but the crystallization depths of the later episode magmas can increase up to 15-20 km below Moho. The calculated crystallization temperatures decrease from the first episode to the third episode. Isobaric fractional crystallization modeling using the MELTS algorithm constrained the fractionation conditions of Kula magmas. The initial water content of the magmas decreases from the first episode (4 wt.%) to third episode (2 wt. %). Under hydrous conditions and oxygen fugacity equals to QFM+2, up to 26 wt % fractional crystallization of olivine, clinopyroxene, spinel and apatite is required to generate the compositional diversity of the KVP magmas.

  11. Surfactant-enhanced low-pH alkaline flooding

    SciTech Connect

    Peru, D.A. and Co., Columbia, MD . Research Div.); Lorenz, P.B. )

    1990-08-01

    This paper reports sodium bicarbonate investigated as a potential alkaline agent in surfactant-enhanced alkaline flooding because it has very little tendency to dissolve silicate minerals. In experiments performed with Wilmington, CA, crude oil and three types of surfactants, the bicarbonate/surfactant combination caused a marked lowering of interfacial tension (IFT). Bicarbonate protected the surfactant against divalent cations and reduced adsorption of surfactant and polymer on various minerals. Coreflood test confirm that sodium bicarbonate plus surfactant can be an effective alternative to the high-pH flooding process.

  12. Immobilization of cesium in alkaline activated fly ash matrix

    NASA Astrophysics Data System (ADS)

    Fernandez-Jimenez, A.; Macphee, D. E.; Lachowski, E. E.; Palomo, A.

    2005-11-01

    The immobilization potential of alkaline activated fly ash (AAFA) matrices for cesium has been investigated. The presence of Cs in the AAFA pastes, prepared using 8M NaOH solution as activator, showed no significant adverse effects on mechanical strength or microstructure, nor were significant quantities of Cs leached following application of the Toxic Characteristic Leaching Procedure (TCLP) and American Nuclear Society (ANS) 16.1 leaching protocols. Microstructural analysis shows Cs associated with the main reaction product in the AAFA suggesting that cesium is chemically bound rather than physically encapsulated. It is proposed that cesium is incorporated into the alkaline aluminosilicate gel, a precursor for zeolite formation.

  13. Study of point defects in alkaline-earth sulfides

    SciTech Connect

    Pandey, R.; Kunz, A.B.; Vail, J.M.

    1988-11-01

    The results of a computer simulation study of point defects including vacancy, interstitial, and F/sup +/ center in alkaline-earth sulfides are presented. The study is based on ICECAP/HADES simulation procedures and uses empirical interionic potentials obtained from the analysis of macroscopic data for these materials. The results predict the dominance of Schottky disorder and suggest that vacancy migration predominates in alkaline-earth sulfides. Furthermore, the calculated F/sup +/ center absorption energy is in good agreement with the experimental data deduced from the optical stimulated studies in these materials.

  14. Advanced technology for extended endurance alkaline fuel cells

    NASA Astrophysics Data System (ADS)

    Sheibley, D. W.; Martin, R. A.

    Advanced components have been developed for alkaline fuel cells with a view to the satisfaction of NASA Space Station design requirements for extended endurance. The components include a platinum-on-carbon catalyst anode, a potassium titanate-bonded electrolyte matrix, a lightweight graphite electrolyte reservoir plate, a gold-plated nickel-perforated foil electrode substrate, a polyphenylene sulfide cell edge frame material, and a nonmagnesium cooler concept. When incorporated into the alkaline fuel cell unit, these components are expected to yield regenerative operation in a low earth orbit Space Station with a design life greater than 5 years.

  15. Advanced technology for extended endurance alkaline fuel cells

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W.; Martin, R. A.

    1987-01-01

    Advanced components have been developed for alkaline fuel cells with a view to the satisfaction of NASA Space Station design requirements for extended endurance. The components include a platinum-on-carbon catalyst anode, a potassium titanate-bonded electrolyte matrix, a lightweight graphite electrolyte reservoir plate, a gold-plated nickel-perforated foil electrode substrate, a polyphenylene sulfide cell edge frame material, and a nonmagnesium cooler concept. When incorporated into the alkaline fuel cell unit, these components are expected to yield regenerative operation in a low earth orbit Space Station with a design life greater than 5 years.

  16. Tuning NaYF4 Nanoparticles through Alkaline Earth Doping

    PubMed Central

    Chen, Xian; Peng, Dengfeng; Wang, Feng

    2013-01-01

    Phase and size of lanthanide-doped nanoparticles are the most important characteristics that dictate optical properties of these nanoparticles and affect their technological applications. Herein, we present a systematic study to examine the effect of alkaline earth doping on the formation of NaYF4 upconversion nanoparticles. We show that alkaline earth doping has a dual function of tuning particle size of hexagonal phase NaYF4 nanoparticles and stabilizing cubic phase NaYF4 nanoparticles depending on composition and concentration of the dopant ions. The study described here represents a facile and general strategy to tuning the properties of NaYF4 upconversion nanoparticles. PMID:28348353

  17. Alkaline solution absorption of carbon dioxide method and apparatus

    DOEpatents

    Hobbs, D.T.

    1991-01-01

    Disclosed is a method for measuring the concentration of hydroxides (or pH) in alkaline solutions, using the tendency of hydroxides to adsorb CO{sub 2}. The method comprises passing CO{sub 2} over the surface of an alkaline solution in a remote tank before and after measurements of the CO{sub 2} concentration. Comparison of the measurements yields the adsorption fraction from which the hydroxide concentration can be calculated using a correlation of hydroxide or pH to adsorption fraction. A schematic is given of a process system according to a preferred embodiment of the invention. 2 figs.

  18. The alkaline tide and ammonia excretion after voluntary feeding in freshwater rainbow trout.

    PubMed

    Bucking, Carol; Wood, Chris M

    2008-08-01

    We investigated the potential acid-base and nitrogenous waste excretion challenges created by voluntary feeding in freshwater rainbow trout, with particular focus on the possible occurrence of an alkaline tide (a metabolic alkalosis created by gastric HCl secretion during digestion). Plasma metabolites (glucose, urea and ammonia) were measured at various time points before and after voluntary feeding to satiation (approximately 5% body mass meal of dry commercial pellets), as was the net flux of ammonia and titratable alkalinity to the water from unfed and fed fish. Arterial blood, sampled by indwelling catheter, was examined for post-prandial effects on pH, plasma bicarbonate and plasma CO2 tension. There was no significant change in plasma glucose or urea concentrations following feeding, whereas plasma ammonia transiently increased, peaking at threefold above resting values at 12 h after the meal and remaining elevated for 24 h. The increased plasma ammonia was correlated with an increase in net ammonia excretion to the water, with fed fish significantly elevating their net ammonia excretion two- to threefold between 12 and 48 h post feeding. These parameters did not change in unfed control fish. Fed fish likewise increased the net titratable base flux to the water by approximately threefold, which resulted in a transition from a small net acid flux seen in unfed fish to a large net base flux in fed fish. Over 48 h, this resulted in a net excretion of 13 867 micromol kg(-1) more base to the external water than in unfed fish. The arterial blood exhibited a corresponding rise in pH (between 6 and 12 h) and plasma bicarbonate (between 3 and 12 h) following feeding; however, no respiratory compensation was observed, as PaCO2 remained constant. Overall, there was evidence of numerous challenges created by feeding in a freshwater teleost fish, including the occurrence of an alkaline tide, and its compensation by excretion of base to the external water. The possible

  19. Regional scale hydrological and biogeochemical processes controlling high biodiversity of a groundwater fed alkaline fen

    NASA Astrophysics Data System (ADS)

    van der Zee, Sjoerd E. A. T. M.; (D. G.) Cirkel, Gijsbert; (J. P. M) witte, Flip

    2014-05-01

    The high floral biodiversity of groundwater fed fens and mesotrophic grasslands depends on the different chemical signatures of the shallow rainwater fed topsoil water and the slightly deeper geochemically affected groundwater. The relatively abrupt gradients between these two layers of groundwater enable the close proximity of plants that require quite different site factors and have different rooting depths. However, sulphur inflow into such botanically interesting areas is generally perceived as a major threat to biodiversity. Although in Europe atmospheric deposition of sulphur has decreased considerably over the last decades, groundwater pollution by sulphate may still continue due to pyrite oxidation in soil as a result of excessive fertilisation. Inflowing groundwater rich in sulphate can change biogeochemical cycling in nutrient-poor wetland ecosystems because of 'so called' internal eutrophication as well as the accumulation of dissolved sulphide, which is phytotoxic. Complementary to conventions, we propose that upwelling sulphate rich groundwater may, in fact, promote the conservation of rare and threatened alkaline fens: excessive fertilisation and pyrite oxidation also produces acidity, which invokes calcite dissolution, and increased alkalinity and hardness of the inflowing groundwater. For a very species-rich wetland nature reserve, we show that sulphate is reduced and effectively precipitated as iron sulphides, when this calcareous and sulphate rich groundwater flows upward through the organic soil of the investigated nature reserve. Also, we show that sulphate reduction occurs simultaneously with an increase in alkalinity production, which in our case results in active calcite precipitation in the soil. In spite of the occurring sulphate reduction, we found no evidence for internal eutrophication. Extremely low phosphorous concentration in the pore water could be attributed to a high C:P ratio of soil organic matter and co-precipitation with

  20. Alkaline cooking (nixtamalisation) and the reduction in the in vivo toxicity of fumonisin-contaminated corn in a rat feeding Bioassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nixtamalization is a widely used food processing method in which whole kernel corn is cooked and steeped in alkaline water. It reduces the amount of FB1 that can be detected after cooking. However, the fate of FB1 during nixtamalization is not fully understood and potentially toxic reaction produc...

  1. AN EVALUATION OF THE RELATIVE GENOTOXICITY OF ARSENITE, ARSENATE, AND FOUR METHYLATED METABOLITES IN VITRO USING THE ALKALINE SINGLE CELL GEL ASSAY

    EPA Science Inventory

    An Evaluation of the Relative Genotoxicity of Arsenite, Arsenate, and Four Methylated
    Metabolites In Vitro Using the Alkaline Single Cell Gel Assay (ASCG).

    Arsenic ( As) is a genotoxic and carcinogenic metal found in many drinking water systems throughout the world. ...

  2. Hydrogeochemistry of Big Soda Lake, Nevada: An alkaline meromictic desert lake

    USGS Publications Warehouse

    Kharaka, Y.K.; Robinson, S.W.; Law, L.M.; Carothers, W.W.

    1984-01-01

    Big Soda Lake, located near Fallon, Nevada, occupies an explosion crater rimmed by basaltic debris; volcanic activity apparently ceased within the last 10,000 years. This lake has been selected for a detailed multidisciplinary study that will ultimately cover the organic and inorganic hydrogeochemistry of water and sediments because the time at which chemical stratification was initiated is known (~1920) and chemical analyses are available for a period of more than 100 years. Detailed chemical analyses of the waters show that the lake is at present alkaline (pH = 9.7), chemically stratified (meromictic) and is extremely anoxic (total reduced sulfur-410 mg/L as H2S) below a depth of about 35 m. The average concentrations (in mg/L) of Na, K, Mg, Ca, NH3, H2S, alkalinity (as HCO3), Cl, SO4, and dissolved organics (as C) in waters of the upper layer (depth 0 to 32 m) are 8,100, 320, 150, 5.0, < 0.1, < 0.5, 4,100, 7,100, 5,800, and 20 respectively; in the deeper layer (depth 37 to 64 m) they are 27,000, 1,200, 5.6, 0.8, 45, 410, 24,000, 27,500, 6,800, and 60, respectively. Chemical and stable isotope analyses of the waters, ??13C and ??14C values of dissolved total carbonate from this lake and surface and ground waters in the area together with mineral-water equilibrium computations indicate that the waters in the lake are primarily meteoric in origin with the present chemical composition resulting from the following geochemical processes: 1. (1) evaporation and exchange with atmosphere, the dominant processes, 2. (2) mineral-water interactions, including dissolution, precipitation and ion exchange, 3. (3) inflow and outflow of ground water and 4. (4) biological activity of macro- and microorganisms, including sulfate reduction in the water column of the deeper layer at a very high rate of 6.6 ??mol L-1 day-1. ?? 1984.

  3. Acid Mine Drainage Passive Remediation: Potential Use of Alkaline Clay, Optimal Mixing Ratio and Long Term Impacts

    NASA Astrophysics Data System (ADS)

    Plaza, F.; Liang, X.; Wen, Y.; Perone, H.

    2015-12-01

    Acid mine drainage (AMD) is one of the most adverse environmental problems of the mine industry. Surface water and ground water affected by this pollution are characterized by their acidity and the high content of sulfates and heavy metals. In this study, alkaline clay, an industrial waste with a high pH, which is utilized in the alumina refining process, was used as the remediation material to inhibit pyrite oxidation. Through a series of batch and column experiments, complemented with field measurements and geochemical modeling, three important issues associated with this passive and auto sustainable acid mine drainage remediation method were investigated: 1) the potential use of alkaline clay as an AMD remediation material, 2) the adequate alkaline clay/coal refuse mixing ratio (AC/CR) to ensure pH values near to neutral conditions, and, 3) the prediction of long term impacts, in terms of the trends of the main parameters involved in this process such as pH, concentrations of sulfate, iron and other dissolved contaminants. Both field measurements and the samples used for the experiments came from a coal waste site located in Mather, Pennsylvania. Alkaline clay proved to be an effective remediation material for AMD. It was found that 10% AC/CR is an adequate mixing ratio (i.e. the upper limit), which has been also indicated by field measurements. The concentrations of some contaminants such as iron, manganese or sulfate are significantly reduced with the remediation approach, compared to those representative concentrations found in mine tailings. Moreover, results suggest a very reliable long-term stability of the remediation (i.e. neutral pH conditions are maintained), thus enhancing the generation of iron precipitates that could produce pyrite grain coating and hardpan (i.e. cemented layer) on the surface. These processes also made the amended layer less porous, thus increasing water retention and hindering oxygen diffusion.

  4. Multi-decadal increases in dissolved organic carbon and alkalinity flux from the Mackenzie drainage basin to the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Tank, Suzanne E.; Striegl, Robert G.; McClelland, James W.; Kokelj, Steven V.

    2016-05-01

    Riverine exports of organic and inorganic carbon (OC, IC) to oceans are intricately linked to processes occurring on land. Across high latitudes, thawing permafrost, alteration of hydrologic flow paths, and changes in vegetation may all affect this flux, with subsequent implications for regional and global carbon (C) budgets. Using a unique, multi-decadal dataset of continuous discharge coupled with water chemistry measurements for the Mackenzie River, we show major increases in dissolved OC (DOC) and IC (as alkalinity) fluxes since the early 1970s, for a watershed that covers 1.8 M km2 of northwestern Canada, and provides substantial inputs of freshwater and biogeochemical constituents to the Arctic Ocean. Over a 39-year period of record, DOC flux at the Mackenzie mouth increased by 39.3% (44.5 ± 22.6 Gmol), while alkalinity flux increased by 12.5% (61.5 ± 60.1 Gmol). Isotopic analyses and substantial increases in sulfate flux indicate that increases in alkalinity are driven by accelerating sulfide oxidation, a process that liberates IC from rock and soils in the absence of CO2 consumption. Seasonal and sub-catchment trends suggest that permafrost thaw plays an important role in the observed increases in DOC and alkalinity: sub-catchment increases for all constituents are confined to northern, permafrost-affected regions, while observed increases in autumn to winter are consistent with documented landscape-scale changes that have resulted from changing thaw dynamics. This increase in DOC and sulfide-derived alkalinity represents a substantial intensification of land-to-ocean C mobilization, at a level that is significant within the regional C budget. The change we observe, for example, is similar to current and projected future rates of CO2 consumption by weathering in the Mackenzie basin.

  5. Multi-decadal increases in dissolved organic carbon and alkalinity flux from the Mackenzie drainage basin to the Arctic Ocean

    USGS Publications Warehouse

    Tank, Suzanne E.; Striegl, Robert G.; McClelland, James W.; Kokelj, Steven V.

    2016-01-01

    Riverine exports of organic and inorganic carbon (OC, IC) to oceans are intricately linked to processes occurring on land. Across high latitudes, thawing permafrost, alteration of hydrologic flow paths, and changes in vegetation may all affect this flux, with subsequent implications for regional and global carbon (C) budgets. Using a unique, multi-decadal dataset of continuous discharge coupled with water chemistry measurements for the Mackenzie River, we show major increases in dissolved OC (DOC) and IC (as alkalinity) fluxes since the early 1970s, for a watershed that covers 1.8 M km2 of northwestern Canada, and provides substantial inputs of freshwater and biogeochemical constituents to the Arctic Ocean. Over a 39-year period of record, DOC flux at the Mackenzie mouth increased by 39.3% (44.5 ± 22.6 Gmol), while alkalinity flux increased by 12.5% (61.5 ± 60.1 Gmol). Isotopic analyses and substantial increases in sulfate flux indicate that increases in alkalinity are driven by accelerating sulfide oxidation, a process that liberates IC from rock and soils in the absence of CO2 consumption. Seasonal and sub-catchment trends suggest that permafrost thaw plays an important role in the observed increases in DOC and alkalinity: sub-catchment increases for all constituents are confined to northern, permafrost-affected regions, while observed increases in autumn to winter are consistent with documented landscape-scale changes that have resulted from changing thaw dynamics. This increase in DOC and sulfide-derived alkalinity represents a substantial intensification of land-to-ocean C mobilization, at a level that is significant within the regional C budget. The change we observe, for example, is similar to current and projected future rates of CO2 consumption by weathering in the Mackenzie basin.

  6. Alkaline Hypersaline Lakes as Analogs for Ancient Microbial Habitats on Mars

    NASA Technical Reports Server (NTRS)

    McDonald, G. D.; Tsapin, A. I.; Storrie-Lombardi, M. C.; Nealson, K. H.; Brinton, K. L. F.; Sun, H.; Venkateswaren, K.; Tsapin, I.; Melack, J.; Jellison, R.

    1999-01-01

    As the climate of ancient Mars became colder and drier with time, open bodies of water would have entered a regime in which evaporation exceeded input from precipitation or runoff. This would have resulted in increases in salinity and perhaps pH. The last open water on Mars was most likely found in alkaline hypersaline lakes, and these lakes would have been the last surface aquatic habitats for life on Mars. It follows, then, that the biomarkers most likely to be found in ancient sedimentary basins on Mars are those left by organisms adapted to high salt and high pH environments. We have begun to investigate the nature of biological diversity and adaptation to these environments, and the potential for biomarker preservation in them, using Mono Lake as a terrestrial analog environment. Additional information is contained in the original extended abstract.

  7. Alkaline earth metal cation exchange: effect of mobile counterion and dissolved organic matter.

    PubMed

    Indarawis, Katrina; Boyer, Treavor H

    2012-04-17

    The goal of this research was to provide an improved understanding of the interactions between alkaline earth metals and DOM under conditions that are encountered during drinking water treatment with particular focus on cation exchange. Both magnetically enhanced and nonmagnetic cation exchange resins were converted to Na, Mg, Ca, Sr, and Ba mobile counterion forms as a novel approach to investigate the exchange behavior between the cations and the interactions between the cations and DOM. The results show that cation exchange is a robust process for removal of Ca(2+) and Mg(2+) considering competition with cations on the resin surface and presence of DOM. DOM was actively involved during the cation exchange process through complexation, adsorption, and coprecipitation reactions. In addition to advancing the understanding of ion exchange processes for water treatment, the results of this work are applicable to membrane pretreatment to minimize fouling, treatment of membrane concentrate, and precipitative softening.

  8. Methanol synthesis using a catalyst combination of alkali or alkaline earth salts and reduced copper chromite

    DOEpatents

    Tierney, J.W.; Wender, I.; Palekar, V.M.

    1995-01-24

    The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a catalyst combination comprising reduced copper chromite and basic alkali salts or alkaline earth salts. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100--160 C and the pressure range of 40--65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H[sub 2]/CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

  9. Methanol synthesis using a catalyst combination of alkali or alkaline earth salts and reduced copper chromite

    DOEpatents

    Tierney, John W.; Wender, Irving; Palekar, Vishwesh M.

    1995-01-01

    The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a catalyst combination comprising reduced copper chromite and basic alkali salts or alkaline earth salts. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100.degree.-160.degree. C. and the pressure range of 40-65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H.sub.2 /CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

  10. Spatial variability of dissolved phosphorous concentrations and alkaline phosphatase activity in the East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, H.; Chang, J.; Ho, T.; Gong, G.

    2010-12-01

    The concentrations of dissolved inorganic phosphorus (DIP) and alkaline phosphatase activity (APA) have been determined at about 25 sampling stations in the East China Sea since 2003. The stations are mainly distributed from the Changjiang river mouth to northern Taiwan and east to the shelf break. In addition to the Changjiang discharge, we have found a specific nutrient source around a coastal site (122° 2’30’’ E, 28° 40’ N). Elevated DIP and nitrate concentrations have been constantly observed around the sampling station for 8 years, where the surface DIP concentrations are generally around 0.3 µM. The nutrient source may either originate from ground water discharge or coastal upwelling, where lower temperature has been observed in the water column around the station. In general, APA has been negatively correlated with DIP concentrations in the studies sites, with lowest APA around the high DIP station and the Changjiang river mouth.

  11. Evaluation of a process for aqueous alkaline digestion of biomass to produce a liquid fuel

    SciTech Connect

    Alexander, B.F.; Rosson, H.F.

    1983-12-01

    The aqueous alkaline digestion of microcrystalline cellulose was studied over the temperature range of 480-540/sup 0/F (249-282/sup 0/C) at residence times of 10-25 minutes and catalyst (Na/sub 2/CO/sub 3/) loadings of 11-76 g/kg. The reaction products were characterized as an oil fraction, water soluble fraction, gas and residue. Addition of carbon monoxide and synthesis gas (50/50 mole ratio CO/H/sub 2/) and simulated recycle of the water soluble fraction were also investigated. Batch experiments were conducted in a one-liter stirred autoclave equipped with rapid feed injection. The information gained from the experimental program plus that available in the literature was used to design a plant for conversion of wood to fuel oil. The cost of producing oil was then calculated based on this design.

  12. Ca isotope fractionation in a high-alkalinity lake system: Mono Lake, California

    NASA Astrophysics Data System (ADS)

    Nielsen, Laura C.; DePaolo, Donald J.

    2013-10-01

    Precipitation of calcium carbonate minerals from aqueous solutions causes surface-controlled kinetic stable Ca isotope fractionation. The magnitude of fractionation depends on the relative rates of ion attachment to and detachment from the mineral surface, which in turn is predicted to depend on both the saturation state and the solution stoichiometry or the Ca:CO32- activity ratio. Experimental studies have not directly investigated the effects of varying solution stoichiometry on calcium isotope partitioning during calcite or aragonite growth, but natural alkaline lake systems such as Mono Lake, California provide a test bed for the hypothesized stoichiometry dependence. Mono Lake has a Ca:CO32- activity ratio of about 0.0001, seven orders of magnitude lower than ocean water and typical terrestrial freshwater. We present chemical and isotopic measurements of streams, springs, lake water, and precipitated carbonates from the Mono Basin that yield evidence of stoichiometry-dependent Ca isotope fractionation during calcite, aragonite and Mg-calcite precipitation from the alkaline lake water. To estimate the Ca isotope fractionation factors, it is necessary to characterize the lake Ca balance and constrain the variability of lake water chemistry both spatially and temporally. Streams and springs supply Ca to the lake, and a substantial fraction of this supply is precipitated along the lake shore to form tufa towers. Lake water is significantly supersaturated with respect to carbonate minerals, so CaCO3 also precipitates directly from the water column to form carbonate-rich bottom sediments. Growth rate inhibition by orthophosphate likely preserves the high degree of supersaturation in the lake. Strontium isotope ratios are used to estimate the proportions of fresh and alkaline lake water from which each solid carbonate sample precipitated. Carbonate minerals that precipitate directly from lake water (low Ca:CO32-) experience relatively large Ca isotope fractionation

  13. Extracellular Alkalinization as a Defense Response in Potato Cells

    PubMed Central

    Moroz, Natalia; Fritch, Karen R.; Marcec, Matthew J.; Tripathi, Diwaker; Smertenko, Andrei; Tanaka, Kiwamu

    2017-01-01

    A quantitative and robust bioassay to assess plant defense response is important for studies of disease resistance and also for the early identification of disease during pre- or non-symptomatic phases. An increase in extracellular pH is known to be an early defense response in plants. In this study, we demonstrate extracellular alkalinization as a defense response in potatoes. Using potato suspension cell cultures, we observed an alkalinization response against various pathogen- and plant-derived elicitors in a dose- and time-dependent manner. We also assessed the defense response against a variety of potato pathogens, such as protists (Phytophthora infestans and Spongospora subterranea) and fungi (Verticillium dahliae and Colletotrichum coccodes). Our results show that extracellular pH increases within 30 min in proportion to the number of pathogen spores added. Consistently with the alkalinization effect, the higher transcription level of several defense-related genes and production of reactive oxygen species was observed. Our results demonstrate that the alkalinization response is an effective marker to study early stages of defense response in potatoes. PMID:28174578

  14. Oxygen electrodes for rechargeable alkaline fuel cells-II

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.

    1989-01-01

    The primary objective of this program is the investigation and development of electrocatalysts and supports for the positive electrode of moderate temperature single-unit rechargeable alkaline fuel cells. Approximately six support materials and five catalyst materials have been identified to date for further development.

  15. Alkaline fuel cells for prime power and energy storage

    NASA Astrophysics Data System (ADS)

    Stedman, J. K.

    Alkaline fuel cell technology and its application to future space missions requiring high power and energy storage are discussed. Energy densities exceeding 100 watthours per pound and power densities approaching 0.5 pounds per kilowatt are calculated for advanced systems. Materials research to allow reversible operation of cells for energy storage and higher temperature operation for peaking power is warranted.

  16. Extracellular Alkalinization as a Defense Response in Potato Cells.

    PubMed

    Moroz, Natalia; Fritch, Karen R; Marcec, Matthew J; Tripathi, Diwaker; Smertenko, Andrei; Tanaka, Kiwamu

    2017-01-01

    A quantitative and robust bioassay to assess plant defense response is important for studies of disease resistance and also for the early identification of disease during pre- or non-symptomatic phases. An increase in extracellular pH is known to be an early defense response in plants. In this study, we demonstrate extracellular alkalinization as a defense response in potatoes. Using potato suspension cell cultures, we observed an alkalinization response against various pathogen- and plant-derived elicitors in a dose- and time-dependent manner. We also assessed the defense response against a variety of potato pathogens, such as protists (Phytophthora infestans and Spongospora subterranea) and fungi (Verticillium dahliae and Colletotrichum coccodes). Our results show that extracellular pH increases within 30 min in proportion to the number of pathogen spores added. Consistently with the alkalinization effect, the higher transcription level of several defense-related genes and production of reactive oxygen species was observed. Our results demonstrate that the alkalinization response is an effective marker to study early stages of defense response in potatoes.

  17. [Granulocyte alkaline phosphatase--a biomarker of chronic benzene exposure].

    PubMed

    Khristeva, V; Meshkov, T

    1994-01-01

    In tracing the cellular population status in the peripheral blood of workers, exposed to benzene, was included and cytochemical determination of the alkaline phosphatase activity in leucocytes. This enzyme is accepted as marker of the neutrophilic granulocytes, as maturation of the cells and their antibacterial activity are parallel to the cytochemical activity of the enzyme. 78 workers from the coke-chemical production from state firm "Kremikovtsi" and 41 workers from the production "Benzene" and "Isopropylbenzene"--Oil Chemical Plant, Burgas are included. The benzene concentrations in the air of the working places in all productions are in the range of 5 to 50 mg/m3. For cytochemical determination of the alkaline phosphatase activity is used the method of L. Kaplow and phosphatase index was calculated. It was established that in 98.4% of all examined the alkaline phosphatase activity is inhibited to different rate, as from 46.5% [61 workers] it is zero. In considerably lower percentage of workers were established and other deviations: leucocytosis or leucopenia, neutropenia, increased percent of band neutrophils and toxic granules. The results of the investigation of the granulocyte population show that from all indices, the activity of granulocyte alkaline phosphatase demonstrates most convincing the early myelotoxic effect of benzene.

  18. The catalytic properties of alkaline phosphatases under various conditions

    NASA Astrophysics Data System (ADS)

    Atyaksheva, L. F.; Chukhrai, E. S.; Poltorak, O. M.

    2008-11-01

    A comparative study was performed to examine the catalytic properties of alkaline phosphatases from bacteria Escherichia coli and bovine and chicken intestines. The activity of enzyme dimers and tetramers was determined. The activity of the dimer was three or four times higher than that of the tetramer. The maximum activity and affinity for 4-nitrophenylphosphate was observed for the bacterial alkaline phosphatase ( K M = 1.7 × 10-5 M, V max = 1800 μmol/(min mg of protein) for dimers and V max = 420 μmol/(min mg of protein) for tetramers). The Michaelis constants were equal for two animal phosphatases in various buffer media (pH 8.5) ((3.5 ± 0.2) × 10-4 M). Five buffer systems were investigated: tris, carbonate, hepes, borate, and glycine buffers, and the lowest catalytic activity of alkaline phosphatases at equal pH was observed in the borate buffer (for enzyme from bovine intestine, V max = 80 μmol/(min mg of protein)). Cu2+ cations formed a complex with tris-(oxymethyl)-aminomethane ( tris-HCl buffer) and inhibited the intestine alkaline phosphatases by a noncompetitive mechanism.

  19. Alkalinity and hardness: Critical but elusive concepts in aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Total alkalinity and total hardness are familiar variables to those involved in aquatic animal production. Aquaculturists – both scientists and practitioners alike – tend to have some understanding of the two variables and of methods for adjusting their concentrations. The chemistry and the biolog...

  20. Alkaline extraction of phenolic compounds from intact sorghum kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An aqueous sodium hydroxide solution was employed to extract phenolic compounds from whole grain sorghum without decortication or grinding as determined by Oxygen Radical Absorbance Capacity (ORAC). The alkaline extract ORAC values were more stable over 32 days compared to neutralized and freeze dri...

  1. Mammalian intestinal alkaline phosphatase acts as highly active exopolyphosphatase.

    PubMed

    Lorenz, B; Schröder, H C

    2001-06-11

    Recent results revealed that inorganic polyphosphates (polyP), being energy-rich linear polymers of orthophosphate residues known from bacteria and yeast, also exist in higher eukaryotes. However, the enzymatic basis of their metabolism especially in mammalian cells is still uncertain. Here we demonstrate for the first time that alkaline phosphatase from calf intestine (CIAP) is able to cleave polyP molecules up to a chain length of about 800. The enzyme acts as an exopolyphosphatase degrading polyP in a processive manner. The pH optimum is in the alkaline range. Divalent cations are not required for catalytic activity but inhibit the degradation of polyP. The rate of hydrolysis of short-chain polyP by CIAP is comparable to that of the standard alkaline phosphatase (AP) substrate p-nitrophenyl phosphate. The specific activity of the enzyme decreases with increasing chain length of the polymer both in the alkaline and in the neutral pH range. The K(m) of the enzyme also decreases with increasing chain length. The mammalian tissue non-specific isoform of AP was not able to hydrolyze polyP under the conditions applied while the placental-type AP and the bacterial (Escherichia coli) AP displayed polyP-degrading activity.

  2. Oxygen electrodes for rechargeable alkaline fuel cells, 3

    NASA Astrophysics Data System (ADS)

    Swette, L.; Kackley, N.; McCatty, S. A.

    1991-09-01

    The investigation and development of electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells is described. Focus is on chemical and electrochemical stability and O2 reduction/evolution activity of the electrode in question.

  3. Alkaline regenerative fuel cell systems for energy storage

    SciTech Connect

    Schubert, F.H.; Reid, M.A.; Martin, R.E.

    1981-01-01

    This paper presents the results of a preliminary design study of a Regenerative Fuel Cell Energy Storage system for application to future low-earth orbit space missions. This high energy density storage system is based on state-of-the-art alkaline electrolyte cell technology and incorporates dedicated fuel cell and electrolysis cell modules. 11 refs.

  4. Oxygen electrodes for rechargeable alkaline fuel cells, 3

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.; Mccatty, S. A.

    1991-01-01

    The investigation and development of electrocatalysts and supports for the positive electrode of moderate temperature single unit rechargeable alkaline fuel cells is described. Focus is on chemical and electrochemical stability and O2 reduction/evolution activity of the electrode in question.

  5. Ocean alkalinity and the Cretaceous/Tertiary boundary

    NASA Technical Reports Server (NTRS)

    Caldeira, K. G.; Rampino, Michael R.

    1988-01-01

    A biogeochemical cycle model resolving ocean carbon and alkalinity content is applied to the Maestrichtian and Danian. The model computes oceanic concentrations and distributions of Ca(2+), Mg(2+), and Sigma-CO2. From these values an atmospheric pCO2 value is calculated, which is used to estimate rates of terrestrial weathering of calcite, dolomite, and calcium and magnesium silicates. Metamorphism of carbonate rocks and the subsequent outgassing of CO2 to the atmosphere are parameterized in terms of carbonate rock reservoir sizes, total land area, and a measure of overall tectonic activity, the sea-floor generation rate. The ocean carbon reservoir computed by the model is used with Deep Sea Drilling Project (DSDP) C-13 data to estimate organic detrital fluxes under a variety of ocean mixing rate assumptions. Using Redfield ratios, the biogenic detrital flux estimate is used to partition the ocean carbon and alkalinity reservoirs between the mixed layer and deep ocean. The calcite flux estimate and carbonate ion concentrations are used to determine the rate of biologically mediated CaCO3 titration. Oceanic productivity was severely limited for approximately 500 kyr following the K/T boundary resulting in significant increases in total ocean alkalinity. As productivity returned to the ocean, excess carbon and alkalinity was removed from the ocean as CaCO3. Model runs indicate that this resulted in a transient imbalance in the other direction. Ocean chemistry returned to near-equilibrium by about 64 mybp.

  6. Yield performance of cowpea genotypes grown in alkaline soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22-25% protein. The crop is very sensitive to alkaline soil conditions. When grown at soil pH of 7.5 or higher, cowp...

  7. Field screening of cowpea cultivars for alkaline soil tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22-25% protein. The crop is very sensitive to alkaline soil conditions. When grown at soil pH of 7.5 or higher, cowp...

  8. Alkaline Phosphatase Revisited:  Hydrolysis of Alkyl Phosphates (†).

    PubMed

    O'Brien, Patrick J; Herschlag, Daniel

    2002-03-05

    Escherichia coli alkaline phosphatase (AP) is the prototypical two metal ion catalyst with two divalent zinc ions bound ∼4 Å apart in the active site. Studies spanning half a century have elucidated many structural and mechanistic features of this enzyme, rendering it an attractive model for investigating the potent catalytic power of bimetallic centers. Unfortunately, fundamental mechanistic features have been obscured by limitations with the standard assays. These assays generate concentrations of inorganic phosphate (Pi) in excess of its inhibition constant (K i ≈ 1 μM). This tight binding by Pi has affected the majority of published kinetic constants. Furthermore, binding limits k cat/K m for reaction of p-nitrophenyl phosphate, the most commonly employed substrate. We describe a sensitive (32)P-based assay for hydrolysis of alkyl phosphates that avoids the complication of product inhibition. We have revisited basic mechanistic features of AP with these alkyl phosphate substrates. The results suggest that the chemical step for phosphorylation of the enzyme limits k cat/K m. The pH-rate profile and additional results suggest that the serine nucleophile is active in its anionic form and has a pK a of ≤5.5 in the free enzyme. An inactivating pK a of 8.0 is observed for binding of both substrates and inhibitors, and we suggest that this corresponds to ionization of a zinc-coordinated water molecule. Counter to previous suggestions, inorganic phosphate dianion appears to bind to the highly charged AP active site at least as strongly as the trianion. The dependence of k cat/K m on the pK a of the leaving group follows a Brønsted correlation with a slope of βlg = -0.85 ± 0.1, differing substantially from the previously reported value of -0.2 obtained from data with a less sensitive assay. This steep leaving group dependence is consistent with a largely dissociative transition state for AP-catalyzed hydrolysis of phosphate monoesters. The new (32)P

  9. Non-Newtonian Rheology of Calc-Alkaline Obsidian at High Stresses and Strain Rates

    NASA Astrophysics Data System (ADS)

    Dingwell, D. B.; Hess, K.; Lavallee, Y.; Cordonnier, B.; Mueller, S.

    2005-12-01

    The importance of the Non-Newtonian regime at high stress and strain rates has been reported for a variety of silicate melts subject to different tests but never for natural samples bearing their original contents of magmatic water and microlite content. Here, we used a unique high-load (<500 MPa), high-temperature (<1300°C) deformation apparatus for studying in situ the Non-Newtonian flow behaviour of magmas. A series of experiments were performed on calc-alkaline obsidian lavas from Lipari (Italy), Iceland, and Cougar Creek Dome, Yellowstone (USA), and compared to depolymerized melt (NIST 710). The samples were heated to relevant magmatic effusive temperatures that yielded similar relaxation timescales and were deformed under constant stress in the range of 100 to 200 MPa. The onset of the Non-Newtonian flow regime, registered by a decreasing viscosity with time (at fixed strain rate), occurred at 120 MPa for the depolymerized melt. The Non-Newtonian flow behavior was observed up to pressures as high as approx. 180 MPa, where the samples fragmented readily (hot cracking). In contrast, all three calc-alkaline rhyolitic melt remained in a Newtonian regime up to approx. 160 MPa. The window of Non-Newtonian behavior was, however, very narrow and most samples fragmented instantaneously in the attempt of pursuing the deformation. If this is not an experimental artefact, we conclude that modeling of the flow behaviour of a ascending crystal- and bubble-free calc-alkaline rhyolitic dome magma can be performed using a simple Newtonian fluid approximation. Thus the Non-Arrhenian model of Hess and Dingwell (1996) for the compositional and temperature dependence of viscosity could be applied.

  10. Gene expression changes leading extreme alkaline tolerance in Amur ide (Leuciscus waleckii) inhabiting soda lake

    PubMed Central

    2013-01-01

    Background Amur ide (Leuciscus waleckii) is an economically and ecologically important cyprinid species in Northern Asia. The Dali Nor population living in the soda lake Dali Nor can adapt the extremely high alkalinity, providing us a valuable material to understand the adaptation mechanism against extreme environmental stress in teleost. Results In this study, we generated high-throughput RNA-Seq data from three tissues gill, liver and kidney of L. waleckii living in the soda lake Dali Nor and the fresh water lake Ganggeng Nor, then performed parallel comparisons of three tissues. Our results showed that out of assembled 64,603 transcript contigs, 28,391 contigs had been assigned with a known function, corresponding to 20,371 unique protein accessions. We found 477, 2,761 and 3,376 differentially expressed genes (DEGs) in the gill, kidney, and liver, respectively, of Dali Nor population compared to Ganggeng Nor population with FDR ≤ 0.01and fold-change ≥ 2. Further analysis revealed that well-known functional categories of genes and signaling pathway, which are associated with stress response and extreme environment adaptation, have been significantly enriched, including the functional categories of “response to stimulus”, “transferase activity”, “transporter activity” and “oxidoreductase activity”, and signaling pathways of “mTOR signaling”, “EIF2 signaling”, “superpathway of cholesterol biosynthesis”. We also identified significantly DEGs encoding important modulators on stress adaptation and tolerance, including carbonic anhydrases, heat shock proteins, superoxide dismutase, glutathione S-transferases, aminopeptidase N, and aminotransferases. Conclusions Overall, this study demonstrated that transcriptome changes in L. waleckii played a role in adaptation to complicated environmental stress in the highly alkalized Dali Nor lake. The results set a foundation for further analyses on alkaline-responsive candidate genes, which help

  11. Microbial community succession in alkaline, saline bauxite residue: a cross-refinery study

    NASA Astrophysics Data System (ADS)

    Santini, T.; Malcolm, L. I.; Tyson, G. W.; Warren, L. A.

    2015-12-01

    Bauxite residue, a byproduct of the Bayer process for alumina refining, is an alkaline, saline tailings material that is generally considered to be inhospitable to microbial life. In situ remediation strategies promote soil formation in bauxite residue by enhancing leaching of saline, alkaline pore water, and through incorporation of amendments to boost organic matter content, decrease pH, and improve physical structure. The amelioration of chemical and physical conditions in bauxite residue is assumed to support diversification of microbial communities from narrow, poorly functioning microbial communities towards diverse, well-functioning communities. This study aimed to characterise microbial communities in fresh and remediated bauxite residues from refineries worldwide, to identify (a) whether initial microbial communities differed between refineries; (b) major environmental controls on microbial community composition; and (c) whether remediation successfully shifts the composition of microbial communities in bauxite residue towards those found in reference (desired endpoint) soils. Samples were collected from 16 refineries and characterised using 16S amplicon sequencing to examine microbial community composition and structure, in conjunction with physicochemical analyses. Initial microbial community composition was similar across refineries but partitioned into two major groups. Microbial community composition changes slowly over time and indicates that alkalinity and salinity inhibit diversification. Microbially-based strategies for in situ remediation should consider the initial microbial community composition and whether the pre-treatment of chemical properties would optimise subsequent bioremediation outcomes. During in situ remediation, microbial communities become more diverse and develop wider functional capacity, indicating progression towards communities more commonly observed in natural grassland and forest soils.

  12. Improving phosphate removal of sand infiltration system using alkaline fly ash.

    PubMed

    Cheung, K C; Venkitachalam, T H

    2000-07-01

    Septic tank effluent is customarily disposed of by soil infiltration. Coarse, sandy soil such as those found in Perth, Western Australia, exhibit low attenuation capabilities for phosphate (PO4(3-)) during effluent infiltration. Amendment of such soil with different amounts of alkaline precipitator and lagoon fly ashes was investigated as a means of reducing phosphorus (P) leakage to ground water. Alkaline precipitator fly ash possessed the highest P sorption capacity in terms of its Langmuir and Freundlich isotherm parameters during initial batch tests. The test materials were repeatedly contacted with fresh PO4(3-) solutions over 90 contacting cycles to gain a better indication of long-term P sorption capability. Again, precipitator fly ash exhibited higher P sorption capacity than lagoon fly ash and Spearwood sand. Column studies assessed the influence of various application rates of alkaline precipitator and lagoon fly ashes on the P removal of septic tank effluent. Septic tank effluent was applied at the rate of 4 cm/day to the column for 12 weeks. Concentrations of P were monitored in the column effluent. All the fly ash columns were more efficient in reducing P migration compared to the sand column. Increased levels of fly ash in the soil columns resulted in increased P attenuation. Lagoon fly ash was inferior to precipitator fly ash for P removal; high application rates of fly ash caused clogging of the infiltration bed apparently due to their lower permeability. It is reasoned that 5-15% precipitator fly ash, and less than 30% lagoon fly ash could be added to coarse sands to produce an infiltration bed, which would result in a better quality effluent than can be obtained with untreated sand alone.

  13. From Geochemistry to Biochemistry: Simulating Prebiotic Chemistry Driven by Geochemical Gradients in Alkaline Hydrothermal Vents

    NASA Astrophysics Data System (ADS)

    Barge, Laurie

    2016-07-01

    Planetary water-rock interfaces generate energy in the form of redox, pH, and thermal gradients, and these disequilibria are particularly focused in hydrothermal vent systems where the reducing, heated hydrothermal fluid feeds back into the more oxidizing ocean. Alkaline hydrothermal vents have been proposed as a likely location for the origin of life on the early Earth due to various factors: including the hydrothermal pH / Eh gradients that resemble the ubiquitous electrical / proton gradients in biology, the catalytic hydrothermal precipitates that resemble inorganic catalysts in enzymes, and the presence of electron donors and acceptors in hydrothermal systems (e.g. H2 + CH4 and CO2) that are thought to have been utilized in the earliest metabolisms. Of particular importance for the emergence of metabolism are the mineral "chimneys" that precipitate at the vent fluid / seawater interface. Hydrothermal chimneys are flow-through chemical reactors that form porous and permeable inorganic membranes transecting geochemical gradients; in some ways similar to biological membranes that transect proton / ion gradients and harness these disequilibria to drive metabolism. These emergent chimney structures in the far-from-equilibrium system of the alkaline vent have many properties of interest to the origin of life that can be simulated in the laboratory: for example, they can generate electrical energy and drive redox reactions, and produce catalytic minerals (in particular the metal sulfides and iron oxyhydroxides - "green rust") that can facilitate chemical reactions towards proto-metabolic cycles and biosynthesis. Many of the factors prompting interest in alkaline hydrothermal vents on Earth may also have been present on early Mars, or even presently within icy worlds such as Europa or Enceladus - thus, understanding the disequilibria and resulting prebiotic chemistry in these systems can be of great use in assessing the potential for other environments in the Solar

  14. Alkaline volcanisms in the Proto-Kuril forearc

    NASA Astrophysics Data System (ADS)

    Yutani, T.; Hirano, N.

    2015-12-01

    The Nemuro Group in the northeasternmost part of Japan represents forearc basin deposits of the Proto-Kuril arc that consist of Upper Cretaceous-Paleocene sedimentary rocks with andesitic volcaniclastics and alkaline lavas. Their occurrence in this setting is unusual because such alkaline lavas and intrusions are not commonly found in forearc environments. Here, we report new petrological and geological data to discuss the nature of magmatic process involved in their petrogenesis. Pillow and massive lava flows represent subaqueous volcanic activity, and the occurrence of inter-pillow sedimentary units indicates their eruption on unconsolidated sediments of the lower Nemuro Group. Sill intrusions with layered structures and thicknesses ranging from 10 to 130 m are also common widely distributed in the Nemuro Group. Major and trace element chemistry and mineralogical data distinguish the analyzed samples as K-rich alkaline rocks with low TiO2 or Nb contents, analogous to island arc-like tholeiites. These K-rich alkaline rocks can be classified into two groups of shoshonites: shoshonites containing olivine phenocrysts and intruding into the lower Nemuro Group (Group 1), and shoshonites with no olivine and making up the middle part of the Nemuro Group (Group 2). Group 1 shoshonites have higher MgO, Cr and Ni contents than those of Group 2. The bulk-rock composition of Group 2, which has lower MgO contents, shows higher SiO2 than that of Group 1. Such compositional differences possibly represent fractional crystallization of magmas between Groups 1 and 2. Based on the limited available data, we conclude that these alkaline rocks intruding into the Nemuro Group represent arc-shoshonites, and that the Group 1 magmas underwent fractional crystallization to produce the Group 2 magmas.

  15. Evaluation of microwave-assisted pretreatment of lignocellulosic biomass immersed in alkaline glycerol for fermentable sugars production.

    PubMed

    Diaz, Ana Belen; Moretti, Marcia Maria de Souza; Bezerra-Bussoli, Carolina; Carreira Nunes, Christiane da Costa; Blandino, Ana; da Silva, Roberto; Gomes, Eleni

    2015-06-01

    A pretreatment with microwave irradiation was applied to enhance enzyme hydrolysis of corn straw and rice husk immersed in water, aqueous glycerol or alkaline glycerol. Native and pretreated solids underwent enzyme hydrolysis using the extract obtained from the fermentation of Myceliophthora heterothallica, comparing its efficiency with that of the commercial cellulose cocktail Celluclast®. The highest saccharification yields, for both corn straw and rice husk, were attained when biomass was pretreated in alkaline glycerol, method that has not been previously reported in literature. Moreover, FTIR, TG and SEM analysis revealed a more significant modification in the structure of corn straw subjected to this pretreatment. Highest global yields were attained with the crude enzyme extract, which might be the result of its content in a great variety of hydrolytic enzymes, as revealed zymogram analysis. Moreover, its hydrolysis efficiency can be improved by its supplementation with commercial β-glucosidase.

  16. Analysis of by-product formation and sugar monomerization in sugarcane bagasse pretreated at pilot plant scale: differences between autohydrolysis, alkaline and acid pretreatment.

    PubMed

    van der Pol, Edwin; Bakker, Rob; van Zeeland, Alniek; Sanchez Garcia, David; Punt, Arjen; Eggink, Gerrit

    2015-04-01

    Sugarcane bagasse is an interesting feedstock for the biobased economy since a large fraction is polymerized sugars. Autohydrolysis, alkaline and acid pretreatment conditions combined with enzyme hydrolysis were used on lignocellulose rich bagasse to acquire monomeric. By-products found after pretreatment included acetic, glycolic and coumaric acid in concentrations up to 40, 21 and 2.5 g/kg dry weight bagasse respectively. Alkaline pretreated material contained up to 45 g/kg bagasse DW of sodium. Acid and autohydrolysis pretreatment results in a furan formation of 14 g/kg and 25 g/kg DW bagasse respectively. Enzyme monomerization efficiencies of pretreated solid material after 72 h were 81% for acid pretreatment, 77% for autohydrolysis and 57% for alkaline pretreatment. Solid material was washed with superheated water to decrease the amount of by-products. Washing decreased organic acid, phenol and furan concentrations in solid material by at least 60%, without a major sugar loss.

  17. Influence of food, aquatic humus, and alkalinity on methylmercury uptake by Daphnia magna

    SciTech Connect

    Monson, B.A.; Brezonik, P.L.

    1999-03-01

    Six-day-old Daphnia magna were exposed to low concentrations of methylmercury (MeHg) in synthetic freshwater and synthetic food. Uptake kinetics were determined in 24- to 72-h experiments, measuring both the loss of Hg from water and accumulation in D. magna. Dose-uptake response was linear for MeHg concentrations up to 4.0 ng/L; an initial concentration of 2.0 ng/L was used when other factors were varied. Concentrations of total Hg and MeHg in water and D. magna were measured in treatments with varied hardness and alkalinity, aquatic humus (AH), and food spiked with MeHg versus water spiked with MeHg. Uptake rate coefficients were derived from two versions of a first-order, two-compartment model. The first version assumed constant MeHg concentration; the second accounted for changing MeHg concentration in water over time. Both models accounted for a nonzero starting concentration of MeHg in plankton. Fitted rate coefficients were higher for the second model than the first: the uptake coefficient (k{sub u}) was nine times higher; the depuration coefficient (k{sub d}) was twice as high. Assuming a constant MeHg concentration for a one-time spike thus underestimated the rate coefficient. The source of MeHg was compared by exposing D. magna for 48 h to MeHg at 2 ng/L in food or water. Daphnia magna accumulated significantly more inorganic Hg (i.e., Hg{sup 2+}) from spiked food than from spiked water, but accumulation of MeHg was the same from both sources. A similar response was found when D. magna were exposed to a lake water extraction of AH at concentrations of C at 3 and 10 mg/L. At the higher AH concentration, total Hg in daphnids was higher, but MeHg was lower, suggesting that AH was a source of inorganic Hg but reduced the bioavailability of MeHg. Exposure of D. magna to MeHg at 2 ng/L in hard or soft water adjusted to pH 6.7 showed no significant difference in MeHg uptake, supporting an argument that hardness and alkalinity per se do not affect MeHg uptake by

  18. Acid rock drainage passive remediation: Potential use of alkaline clay, optimal mixing ratio and long-term impacts.

    PubMed

    Plaza, Fernando; Wen, Yipei; Perone, Hanna; Xu, Yi; Liang, Xu

    2017-01-15

    Acid rock drainage (ARD) is one of the most adverse environmental problems of the mining industry. Surface and ground water affected by this pollution are characterized by their acidity and the high content of sulfates and metals/metalloids. In this study, alkaline clay (AC), an industrial waste with a high alkalinity, which is utilized in the alumina refining process, was used as the remediation material to inhibit pyrite oxidation in waste coal piles. Through a series of laboratory experiments (static and kinetic), complemented with field measurements and geochemical modeling, three important issues associated with this passive and sustainable ARD remediation method were investigated: 1) the potential use of alkaline clay as an ARD remediation material, 2) the adequate alkaline clay/coal refuse mixing ratio (AC/CR) to ensure pH values close to neutral conditions, and, 3) the implications for long-term performance, in terms of the trends of the main parameters involved in this process such as pH, concentrations of sulfate, iron and other dissolved contaminants. Both field measurements and the samples used for the experiments came from a local waste coal site. Through the analysis of the field measurements and the outcome of the laboratory experiments, AC proved to be an effective remediation material for ARD. Compared to those found in mine tailings, the concentrations of contaminants such as iron, manganese or sulfate were significantly reduced with this remediation approach. Moreover, results suggest a reliable long-term stability of the remediation (i.e. neutral pH conditions are maintained), thus enhancing the generation of iron precipitates that could produce pyrite grain coating. These processes also made the amended layer less porous, thus increased water retention and hindered oxygen diffusion.

  19. Oceanic CO[sub 2] measurements for the WOCE Hydrological Survey in the Pacific Ocean; Shipboard Alkalinity analyses during 1991 and 1992

    SciTech Connect

    Keeling, C.D.

    1992-01-01

    Over a period of several years the DOE Carbon Dioxide Science Team is contributing measurements of the carbon cycle in sea water on transects of the WOCE Hydrological Survey sponsored by the United States. As noted in our report of 6 December, 1991, our laboratory is contributing measurements of titration alkalinity of sea water to this effort. This paper discusses technical progress made in 1992.

  20. A New Mechanism in Electrochemical Process for Arsenic Oxidation: Production of H2O2 from Anodic O2 Reduction on the Cathode under Automatically Developed Alkaline Conditions.

    PubMed

    Qian, Ao; Yuan, Songhu; Zhang, Peng; Tong, Man

    2015-05-05

    Electrochemical cathodes are often used to reduce contaminants or produce oxidizing substances (i.e., H2O2). Alkaline conditions develop automatically around the cathode in electrochemical processes, and O2 diffuses onto the cathode easily. However, limited attention is paid to contaminant transformation by the reactive species produced on the cathode under oxic and alkaline conditions due to the inapplicability of pH for Fenton reaction. In this study, a new oxidation mechanism on the cathode is presented for contaminant transformation under automatically developed alkaline conditions. In an electrochemical sand column, 6.67 μM As(III) was oxidized by 36% when it passed through the cathode under the conditions of 30 mA current, an initial pH of 7.5 and a flow rate of 2 mL/min. Under the alkaline conditions (pH 10.0-11.0) that developed automatically around the cathode, the reduction potential of As(III) decreased greatly, allowing a pronounced oxidation by the small quantities of H2O2 produced from O2 reduction on the cathode. As(III) oxidation was further increased by the presence of soil pore water and groundwater solutes of HCO3-, Ca2+, Mg2+ and humic acid. The new oxidation mechanism found for the cathode under localized alkaline conditions supplements the fundamentals of contaminant transformation in electrochemical processes.

  1. Alkaline-fermented foods: a review with emphasis on pidan fermentation.

    PubMed

    Wang, J; Fung, D Y

    1996-01-01

    Alkaline-fermented foods constitute a group of less-known food products that are widely consumed in Southeast Asia and African countries. They can be made from different raw ingredients. For instance, Japanese natto, Thai thua-nao, and kinema are made from cooked soybeans, dawadawa from African locust beans, ogiri from melon seeds, ugba from African oil beans, kawal from fresh legale leaves, owoh from cotton seeds, and pidan from fresh poultry eggs. In alkaline-fermented foods, the protein of the raw materials is broken down into amino acids and peptides; ammonia is released during the fermentation, raising the pH of the final products and giving the food a strong ammoniacal smell. Most alkaline fermentations are achieved spontaneously by mixed bacteria cultures, principally dominated by Bacillus subtilis. In other cases, pure cultures can be used. For example, Japanese natto is inoculated with a pure culture of B. subtilis var natto. Pidan is a special example of alkaline fermentation. Instead of using microorganisms, pidan is made using an alkali-treated fermentation. Sodium hydroxide (NaOH) is produced from the reaction of sodium carbonate (Na2CO3), water (H2O), and calcium oxide (CaO) of pickle or coating mud. NaOH penetrates into the eggs, causing the physicochemical changes, color changes, and gelation. The appearance of pidan differs from fresh eggs in that the white becomes a semitransparent tea-brown color, and the yolk is solid or semisolid with a dark-green color. The nutritional value of pidan is slightly decreased compared with fresh eggs, but pidan has an extremely long shelf life and a pleasant, fragrant taste that is preferred by most people in Southeast Asian countries. In a small-scale laboratory study conducted by the authors, B. subtilis was not found in pidan. Four Staphylococcus spp. (S. cohnii, S. epidermidis, S. haemolyticus, and S. warneri) and two strains of Bacillus spp. (B. cereus and B. macerans) were isolated from pidan. Staphylococcus

  2. Development of composite membranes of PVA-TEOS doped KOH for alkaline membrane fuel cell

    SciTech Connect

    Haryadi, Sugianto, D.; Ristopan, E.

    2015-12-29

    Anion exchange membranes (AEMs) play an important role in separating fuel and oxygen (or air) in the Alkaline Membrane Fuel Cells. Preparation of hybrid organic inorganic materials of Polyvinylalcohol (PVA) - Tetraethylorthosilicate (TEOS) composite membrane doped KOH for direct alcohol alkaline fuel cell application has been investigated. The sol-gel method has been used to prepare the composite membrane of PVA-TEOS through crosslinking step and catalyzed by concentrated of hydrochloric acid. The gel solution was cast on the membrane plastic plate to obtain membrane sheets. The dry membranes were then doped by immersing in various concentrations of KOH solutions for about 4 hours. Investigations of the cross-linking process and the presence of hydroxyl group were conducted by FTIR as shown for frequency at about 1600 cm{sup −1} and 3300 cm{sup −1} respectively. The degree of swelling in ethanol decreased as the KOH concentration for membrane soaking process increased. The ion exchange capacity (IEC) of the membrane was 0.25meq/g. This composite membranes display significant ionic conductivity of 3.23 x 10{sup −2} S/cm in deionized water at room temperature. In addition, the morphology observation by scanning electron microscope (SEM) of the membrane indicates that soaking process of membrane in KOH increased thermal resistant.

  3. Application of alkaline treatment for sludge decrement and humic acid recovery.

    PubMed

    Li, Huan; Jin, Yiying; Nie, Yongfeng

    2009-12-01

    A new method was introduced to reduce waste activated sludge and extract humic acid for liquid fertilizer. Sludge was disintegrated with NaOH (0.4 g/g dry solid, 8 h) and then centrifuged to obtain the supernatant. The residual sludge was then dewatered, while the supernatant was used to extract humic acid with an ultrafiltration membrane. The results showed that the alkaline treatment dissolved more than half of the sludge organic matter, which was composed of 24% humic acid by mass. After the supernatant was concentrated 20 times using a membrane with a molecular weight cutoff of 1000, the retentate contained 94.5% of the dissolved organics and could be used to produce humic acid fertilizer. Additionally, only 26% of the NaOH was consumed and the residual NaOH in the permeate flux could be reused. Due to the removal of water and organics, the dewatered sludge could be reduced by 60% when compared to samples that did not receive the alkaline treatment.

  4. Stability in alkaline aqueous electrolyte of air electrode protected with fluorinated interpenetrating polymer network membrane

    NASA Astrophysics Data System (ADS)

    Bertolotti, Bruno; Messaoudi, Houssam; Chikh, Linda; Vancaeyzeele, Cédric; Alfonsi, Séverine; Fichet, Odile

    2015-01-01

    We developed original anion exchange membranes to protect air electrodes operating in aqueous lithium-air battery configuration, i.e. supplied with atmospheric air and in concentrated aqueous lithium hydroxide. These protective membranes have an interpenetrating polymer network (IPN) architecture combining a hydrogenated cationic polyelectrolyte network based on poly(epichlorohydrin) (PECH) and a fluorinated neutral network based on perfluoropolyether (Fluorolink® MD700). Two phases, each one rich in one of the polymer, are co-continuous in the materials. This morphology allows combining their properties according to the weight proportions of each polymer. Thus, PECH/Fluorolink IPNs show ionic conductivity varying from 1 to 2 mS cm-1, water uptake from 30 to 90 wt.% and anionic transport number from 0.65 to 0.80 when the PECH proportion varies from 40 to 90 wt.%. These membranes have been systematically assembled on air electrodes. Air electrode protected with PECH/Fluorolink 70/30 IPN shows outstanding stability higher than 1000 h, i.e. a 20-fold increase in the lifetime of the non-modified electrode. This efficient membrane/air electrode assembly is promising for development of alkaline electrolyte based storage or production energy systems, such as metal air batteries or alkaline fuel cells.

  5. Flow screen-printed amperometric detection of p-nitrophenol in alkaline phosphatase-based assays.

    PubMed

    Fanjul-Bolado, Pablo; González-García, María Begoña; Costa-García, Agustín

    2006-08-01

    p-Nitrophenyl phosphate is one of the most widely used substrates for alkaline phosphatase in ELISAs because its yellow, water-soluble product, p-nitrophenol, absorbs strongly at 405 nm. p-Nitrophenol is also electroactive; an oxidative peak at 0.97 V (vs. an Ag pseudoreference electrode) is obtained when a bare screen-printed carbon electrode is used. When an amperometric detector was coupled to a flow-injection analysis system the detection limit achieved for p-nitrophenol was 2x10(-8) mol L(-1), almost two orders of magnitude lower than that obtained by measuring the absorbance of the compound. By use of this electrochemical detection method, measurement of 7x10(-14) mol L(-1) alkaline phosphatase was achieved after incubation for 20 min. The feasibility of coupling immunoassay to screen-printed carbon electrode amperometric detection has been demonstrated by performing an ELISA for detection of pneumolysin, a toxin produced by Streptococcus pneumoniae, which causes respiratory infections. The method is simple, reproducible, and much more sensitive than traditional spectrophotometry.

  6. Development of composite membranes of PVA-TEOS doped KOH for alkaline membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Haryadi, Sugianto, D.; Ristopan, E.

    2015-12-01

    Anion exchange membranes (AEMs) play an important role in separating fuel and oxygen (or air) in the Alkaline Membrane Fuel Cells. Preparation of hybrid organic inorganic materials of Polyvinylalcohol (PVA) - Tetraethylorthosilicate (TEOS) composite membrane doped KOH for direct alcohol alkaline fuel cell application has been investigated. The sol-gel method has been used to prepare the composite membrane of PVA-TEOS through crosslinking step and catalyzed by concentrated of hydrochloric acid. The gel solution was cast on the membrane plastic plate to obtain membrane sheets. The dry membranes were then doped by immersing in various concentrations of KOH solutions for about 4 hours. Investigations of the cross-linking process and the presence of hydroxyl group were conducted by FTIR as shown for frequency at about 1600 cm-1 and 3300 cm-1 respectively. The degree of swelling in ethanol decreased as the KOH concentration for membrane soaking process increased. The ion exchange capacity (IEC) of the membrane was 0.25meq/g. This composite membranes display significant ionic conductivity of 3.23 x 10-2 S/cm in deionized water at room temperature. In addition, the morphology observation by scanning electron microscope (SEM) of the membrane indicates that soaking process of membrane in KOH increased thermal resistant.

  7. Matrix diffusion of some alkali- and alkaline earth-metals in granitic rock

    SciTech Connect

    Johansson, H.; Byegaard, J.; Skarnemark, G.; Skaalberg, M.

    1997-12-31

    Static through-diffusion experiments were performed to study the diffusion of alkali- and alkaline earth-metals in fine-grained granite and medium-grained Aespoe-diorite. Tritiated water was used as an inert reference tracer. Radionuclides of the alkali- and alkaline earth-metals (mono- and divalent elements which are not influenced by hydrolysis in the pH-range studied) were used as tracers, i.e., {sup 22}Na{sup +}, {sup 45}Ca{sup 2+} and {sup 85}Sr{sup 2+}. The effective diffusivity and the rock capacity factor were calculated by fitting the breakthrough curve to the one-dimensional solution of the diffusion equation. Sorption coefficients, K{sub d}, that were derived from the rock capacity factor (diffusion experiments) were compared with K{sub d} determined in batch experiments using crushed material of different size fractions. The results show that the tracers were retarded in the same order as was expected from the measured batch K{sub d}. Furthermore, the largest size fraction was the most representative when comparing batch K{sub d} with K{sub d} evaluated from the diffusion experiments. The observed effective diffusivities tended to decrease with increasing cell lengths, indicating that the transport porosity decreases with increasing sample lengths used in the diffusion experiments.

  8. Nixtamalized flour from quality protein maize (Zea mays L). optimization of alkaline processing.

    PubMed

    Milán-Carrillo, J; Gutiérrez-Dorado, R; Cuevas-Rodríguez, E O; Garzón-Tiznado, J A; Reyes-Moreno, C

    2004-01-01

    Quality of maize proteins is poor, they are deficient in the essential amino acids lysine and tryptophan. Recently, in Mexico were successfully developed nutritionally improved 26 new hybrids and cultivars called quality protein maize (QPM) which contain greater amounts of lysine and tryptophan. Alkaline cooking of maize with lime (nixtamalization) is the first step for producing several maize products (masa, tortillas, flours, snacks). Processors adjust nixtamalization variables based on experience. The objective of this work was to determine the best combination of nixtamalization process variables for producing nixtamalized maize flour (NMF) from QPM V-537 variety. Nixtamalization conditions were selected from factorial combinations of process variables: nixtamalization time (NT, 20-85 min), lime concentration (LC, 3.3-6.7 g Ca(OH)2/l, in distilled water), and steep time (ST, 8-16 hours). Nixtamalization temperature and ratio of grain to cooking medium were 85 degrees C and 1:3 (w/v), respectively. At the end of each cooking treatment the steeping started for the required time. Steeping was finished by draining the cooking liquor (nejayote). Nixtamal (alkaline-cooked maize kernels) was washed with running tap water. Wet nixtamal was dried (24 hours, 55 degrees C) and milled to pass through 80-US mesh screen to obtain NMF. Response surface methodology (RSM) was applied as optimization technique, over four response variables: In vitro protein digestibility (PD), total color difference (deltaE), water absorption index (WAI), and pH. Predictive models for response variables were developed as a function of process variables. Conventional graphical method was applied to obtain maximum PD, WAI and minimum deltaE, pH. Contour plots of each of the response variables were utilized applying superposition surface methodology, to obtain three contour plots for observation and selection of best combination of NT (31 min), LC (5.4 g Ca(OH)2/l), and ST (8.1 hours) for producing

  9. Influence of alkaline co-contaminants on technetium mobility in vadose zone sediments.

    PubMed

    Szecsody, Jim E; Jansik, Danielle P; McKinley, James P; Hess, Nancy J

    2014-09-01

    Pertechnetate was slowly reduced in a natural, untreated arid sediment under anaerobic conditions (0.02 nmolg(-1)h(-1)), which could occur in low permeability zones in the field, most of which was quickly oxidized. A small portion of the surface Tc may be incorporated into slowly dissolving surface phases, so was not readily oxidized/remobilized into pore water. In contrast, pertechnetate reduction in an anaerobic sediment containing adsorbed ferrous iron as the reductant was rapid (15-600 nmolg(-1)h(-1)), and nearly all (96-98%) was rapidly oxidized/remobilized (2.6-6.8 nmolg(-1)h(-1)) within hours. Tc reduction in an anaerobic sediment containing 0.5-10mM sulfide showed a relatively slow reduction rate (0.01-0.03 nmolg(-1)h(-1)) that was similar to observations in the natural sediment. Pertechnetate infiltration into sediment with a highly alkaline water resulted in rapid reduction (0.07-0.2 nmolg(-1)h(-1)) from ferrous iron released during biotite or magnetite dissolution. Oxidation of NaOH-treated sediments resulted in slow Tc oxidation (∼0.05 nmolg(-1)h(-1)) of a small fraction of the surface Tc (13-23%). The Tc remaining on the surface was Tc(IV) (by XANES), and autoradiography and elemental maps of Tc (by electron microprobe) showed Tc was present associated with specific minerals, rather than being evenly distributed on the surface. Dissolution of quartz, montmorillonite, muscovite, and kaolinite also occurred in the alkaline water, resulting in significant aqueous silica and aluminum. Over time, aluminosilicates, cancrinite, zeolite and sodalite were precipitating. These precipitates may be coating surface Tc(IV) phases, limiting reoxidation.

  10. Influence of Alkaline Co-Contaminants on Technetium Mobility in Vadose Zone Sediments

    SciTech Connect

    Szecsody, James E.; Jansik, Danielle P.; McKinley, James P.; Hess, Nancy J.

    2014-09-01

    Pertechnetate was slowly reduced in a natural, untreated arid sediment under anaerobic conditions (0.02 nmol g-1 h-1), which could occur in low permeability zones in the field, most of which was quickly oxidized. A small portion of the surface Tc may be incorporated into slowly dissolving surface phases, so was not readily oxidized/remobilized into pore water. In contrast, pertechnetate reduction in an anaerobic sediment containing adsorbed ferrous iron as the reductant was rapid (15 to 600 nmol g-1 h-1), and nearly all (96 - 98%) was rapidly oxidized/remobilized (2.6 to 6.8 nmol g-1 h-1) within hours. Tc reduction in an anaerobic sediment containing 0.5 to 10 mM sulfide showed a relatively slow reduction rate (0.01 to 0.03 nmol g-1 h-1) that was similar to observations in the natural sediment. Pertechnetate infiltration into sediment with a highly alkaline water resulted in rapid reduction (0.07 to 0.2 nmol g-1 h-1) from ferrous iron released during biotite or magnetite dissolution. Oxidation of NaOH-treated sediments resulted in slow Tc oxidation (~0.05 nmol g-1 h-1) of a small fraction of the surface Tc (13% to 23%). The Tc remaining on the surface was TcIV (by XANES), and autoradiography and elemental maps of Tc (by electron microprobe) showed Tc was present associated with specific minerals, rather than being evenly distributed on the surface. Dissolution of quartz, montmorillonite, muscovite, and kaolinite also occurred in the alkaline water, resulting in significant aqueous silica and aluminum. Over time, aluminosilicates cancrinite, zeolite and sodalite were precipitating. These precipitates may be coating surface Tc(IV) phases, limiting reoxidation.

  11. Low temperature alkaline pH hydrolysis of oxygen-free Titan tholins

    NASA Astrophysics Data System (ADS)

    Brassé, C.; Buch, A.; Raulin, F.; Coll, P.; Poch, O.; Ramirez, S.

    2013-09-01

    Titan, the largest moon of Saturn, is known for its dense and nitrogen-rich atmosphere. The organic aerosols which are produced in Titan's atmosphere are objects of astrobiological interest. In this paper we focus on their potential chemical evolution when they reach the surface and interact with putative ammonia-water cryomagma[1]. In this context we have studied the evolution of alkaline pH hydrolysis of Titan tholins (produced by an experimental setup using a plasma DC discharge named PLASMA) at ambient and low temperature. However, we identified oxygenated molecules in non-hydrolyzed tholins meaning that oxygen gets in the PLASMA reactor during the tholins synthesis [2]. Following this preliminary study the synthesis protocol has been improved by isolating the whole device in a specially designed glove box which protect the PLASMA experiment from the laboratory atmosphere. After confirming the non-presence of oxygen in tholins produced with this new experimental setup, the study of oxygen-free tholins' evolution has been carried out. A recent study shows that the subsurface ocean may contain a lower fraction of ammonia (about 5wt% or less [3]), as previously described by other teams [2,4]. Thus new hydrolysis experiments will take this lower value into account. Additionally, a new report [5] provides upper and lower limits for the bulk content of Titan's interior for various gas species. It also shows that most of them are likely stored and dissolved in the subsurface water ocean. But considering the plausible acido-alkaline properties of the ammonia-water ocean, additional species could be dissolved in the ocean and present in the magma. They were also included in our hydrolysis experiments. Taking into account these new data, four different hydrolysis have been applied to oxygen-free tholins. For each type of hydrolysis, we also follow the influence of the hydrolysis temperature on the organic molecules production. The preliminary qualitative and quantitative

  12. The potential for constructed wetlands to treat alkaline bauxite residue leachate: laboratory investigations.

    PubMed

    R, Buckley; T, Curtin; R, Courtney

    2016-07-01

    High alkalinity (pH > 12) of bauxite residue leachates presents challenges for the long-term storage and managements of the residue. Whilst the use of constructed wetlands is gaining in interest for its use in the treatment of alkaline waters, thus far, there is limited evidence of its suitability for treating NaOH dominated bauxite residue leachate. A series of batch trials were conducted to investigate the potential for constructed wetland conferred mechanisms (dilution water quality, contact with CO2, and substrate type) for treating NaOH solutions to levels permissible for discharge (p < 9). Results demonstrate that significant reductions in solution pH can be achieved depending on the diluting water quality. Levels achieved may not always be suitable for direct discharge (i.e. pH ≤ 9), but further reductions occur with carbonation and soil contact. The extent of pH decrease and the timeframe required are influenced by soil quality, with greater efficiency observed in soils with higher organic matter content. Decrease in solution pH to discharge permit values are possible through a combination of the mechanisms occurring in a constructed wetland. Formation of a calcite precipitate was observed in some treatments and further characterisation by XRD and XPS suggested surface coating with Na2CO3. It is therefore suggested that, under suitable conditions, constructed wetland technology can reduce leachate pH to <9 through mechanisms supporting the precipitation of sodium carbonate from solution. Further trials should investigate the activity under biological conditions representative of an operating constructed wetland.

  13. Alkaline pH Homeostasis in Bacteria: New Insights

    PubMed Central

    Padan, Etana; Bibi, Eitan; Ito, Masahiro; Krulwich, Terry A.

    2011-01-01

    The capacity of bacteria to survive and grow at alkaline pH values is of widespread importance in the epidemiology of pathogenic bacteria, in remediation and industrial settings, as well as in marine, plant-associated and extremely alkaline ecological niches. Alkali-tolerance and alkaliphily, in turn, strongly depend upon mechanisms for alkaline pH homeostasis, as shown in pH shift experiments and growth experiments in chemostats at different external pH values. Transcriptome and proteome analyses have recently complemented physiological and genetic studies, revealing numerous adaptations that contribute to alkaline pH homeostasis. These include elevated levels of transporters and enzymes that promote proton capture and retention (e.g. the ATP synthase and monovalent cation/proton antiporters), metabolic changes that lead to increased acid production, and changes in the cell surface layers that contribute to cytoplasmic proton retention. Targeted studies over the past decade have followed up the long-recognized importance of monovalent cations in active pH homeostasis. These studies show the centrality of monovalent cation/proton antiporters in this process while microbial genomics provides information about the constellation of such antiporters in individual strains. A comprehensive phylogenetic analysis of both eukaryotic and prokaryotic genome databases has identified orthologes from bacteria to humans that allow better understanding of the specific functions and physiological roles of the antiporters. Detailed information about the properties of multiple antiporters in individual strains is starting to explain how specific monovalent cation/proton antiporters play dominant roles in alkaline pH homeostasis in cells that have several additional antiporters catalyzing ostensibly similar reactions. New insights into the pH-dependent Na+/H+ antiporter NhaA that plays an important role in Escherichia coli have recently emerged from the determination of the structure

  14. 40 CFR 721.4668 - Hydrated alkaline earth metal salts of metalloid oxyanions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hydrated alkaline earth metal salts of... Specific Chemical Substances § 721.4668 Hydrated alkaline earth metal salts of metalloid oxyanions. (a... hydrated alkaline earth metal salts of metalloid oxyanions (PMN P-94-1557) is subject to reporting...

  15. 40 CFR 721.4668 - Hydrated alkaline earth metal salts of metalloid oxyanions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Hydrated alkaline earth metal salts of... Specific Chemical Substances § 721.4668 Hydrated alkaline earth metal salts of metalloid oxyanions. (a... hydrated alkaline earth metal salts of metalloid oxyanions (PMN P-94-1557) is subject to reporting...

  16. 40 CFR 721.4668 - Hydrated alkaline earth metal salts of metalloid oxyanions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Hydrated alkaline earth metal salts of... Specific Chemical Substances § 721.4668 Hydrated alkaline earth metal salts of metalloid oxyanions. (a... hydrated alkaline earth metal salts of metalloid oxyanions (PMN P-94-1557) is subject to reporting...

  17. 40 CFR 420.110 - Applicability; description of the alkaline cleaning subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... alkaline cleaning subcategory. 420.110 Section 420.110 Protection of Environment ENVIRONMENTAL PROTECTION... Alkaline Cleaning Subcategory § 420.110 Applicability; description of the alkaline cleaning subcategory... publicly owned treatment works resulting from operations in which steel and steel products are immersed...

  18. 40 CFR 420.110 - Applicability; description of the alkaline cleaning subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... alkaline cleaning subcategory. 420.110 Section 420.110 Protection of Environment ENVIRONMENTAL PROTECTION... Alkaline Cleaning Subcategory § 420.110 Applicability; description of the alkaline cleaning subcategory... publicly owned treatment works resulting from operations in which steel and steel products are immersed...

  19. 40 CFR 420.110 - Applicability; description of the alkaline cleaning subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alkaline cleaning subcategory. 420.110 Section 420.110 Protection of Environment ENVIRONMENTAL PROTECTION... Alkaline Cleaning Subcategory § 420.110 Applicability; description of the alkaline cleaning subcategory... publicly owned treatment works resulting from operations in which steel and steel products are immersed...

  20. 40 CFR 420.110 - Applicability; description of the alkaline cleaning subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkaline cleaning subcategory. 420.110 Section 420.110 Protection of Environment ENVIRONMENTAL PROTECTION... Alkaline Cleaning Subcategory § 420.110 Applicability; description of the alkaline cleaning subcategory... publicly owned treatment works resulting from operations in which steel and steel products are immersed...