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Sample records for water electrolytes vitamins

  1. Water, electrolytes, vitamins and trace elements – Guidelines on Parenteral Nutrition, Chapter 7

    Directory of Open Access Journals (Sweden)

    Working group for developing the guidelines for parenteral nutrition of The German Association for Nutritional Medicine

    2009-11-01

    Full Text Available A close cooperation between medical teams is necessary when calculating the fluid intake of parenterally fed patients. Fluids supplied parenterally, orally and enterally, other infusions, and additional fluid losses (e.g. diarrhea must be considered. Targeted diagnostic monitoring (volume status is required in patients with disturbed water or electrolyte balance. Fluid requirements of adults with normal hydration status is approximately 30–40 ml/kg body weight/d, but fluid needs usually increase during fever. Serum electrolyte concentrations should be determined prior to PN, and patients with normal fluid and electrolyte balance should receive intakes follwing standard recommendations with PN. Additional requirements should usually be administered via separate infusion pumps. Concentrated potassium (1 mval/ml or 20% NaCl solutions should be infused via a central venous catheter. Electrolyte intake should be adjusted according to the results of regular laboratory analyses. Individual determination of electrolyte intake is required when electrolyte balance is initially altered (e.g. due to chronic diarrhea, recurring vomiting, renal insufficiency etc.. Vitamins and trace elements should be generally substituted in PN, unless there are contraindications. The supplementation of vitamins and trace elements is obligatory after a PN of >1 week. A standard dosage of vitamins and trace elements based on current dietary reference intakes for oral feeding is generally recommended unless certain clinical situations require other intakes.

  2. Water Soluable Vitamins and Ageing

    Science.gov (United States)

    Since their discovery in the early part of the 20th century, the importance of the water soluble B complex vitamins and vitamin C to the maintenance of healthy tissue and prevention of disease has been recognized. Deficiency of these vitamins led to severe consequences. Fortunately, the discovery of...

  3. Effects of Antioxidant Vitamin Combination on Electrolyte Status in Pregnancy

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    O.I. Iribhogbe

    2011-02-01

    Full Text Available It is a known fact that hypertension is associated with pregnancy. Several studies have reported a link between hypertension and a shift in serum electrolyte concentration. This study is designed to investigate the effect of antioxidant vitamin A, C and E bi- combination on electrolyte status in pregnancy. In a bid to investigate the above objective, varying combination of antioxidant vitamin A, C and E were administered to 70 pregnant Wister albino rats. These were assigned into two control groups treated with distilled H2O and vehicle- tween-80 respectively and three cohorts (I, II and III with four sub-groups each (n = 5. Beginning from the 7th day, test group I received a varying dose combination of vitamin A+C, group II vitamin A+E, and group III vitamin C+E respectively for 11 days. Results revealed a non significant reduction (p>0.05 in serum Na+ and Ca2+, and a significant change p<0.05 in serum Cl- and K+ following Vit A+C administration when compared with control. The group treated with Vit A+E combination presented a non significant change in serum Na+, Cl-, K+ and Ca2+ level. Vit C+E treated group presented a significant reduction (p<0.05 in serum Na+, K+ and Ca2+ with no alteration in serum Cl-. In conclusion, antioxidant vitamin A, C and E bi-combination ameliorates the reported high Na+ concentration in pregnancy and may be of significance as adjuvants in the management of hypertension in pregnancy. However, the importance of further research cannot be overemphasized.

  4. Electrolytic silver ion cell sterilizes water supply

    Science.gov (United States)

    Albright, C. F.; Gillerman, J. B.

    1968-01-01

    Electrolytic water sterilizer controls microbial contamination in manned spacecraft. Individual sterilizer cells are self-contained and require no external power or control. The sterilizer generates silver ions which do not impart an unpleasant taste to water.

  5. A Capillary Electrophoresis Detection Scheme for Water-soluble Vitamins Based on Luminol - BrO- Chemiluminescence System

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel chemiluminescence detection scheme has been developed for detecting water-soluble vitamins following capillary electrophoresis (CE) separation. This detection was based on the inhibitory effect of vitamins on the CL reaction between luminol and BrO- in basic aqueous solution. Detection of vitamins was accomplished with a borate-based background electrolyte at pH 9.2. The luminol was used as a component of the separation carrier electrolyte.

  6. Electrolyte & water metabolism in sports activities.

    Science.gov (United States)

    Whang, R

    1998-01-01

    Few studies in water and electrolyte metabolism during sports activities have directed attention to magnesium. Addition of magnesium to sports beverages in appropriate concentrations appears to be safe. This article considers the potential role and availability of magnesium in fluid repletion during sports activities.

  7. Effects of vitamin E on serum enzymes and electrolytes in hypercholesterolemia.

    Science.gov (United States)

    Prasad, Kailash

    2010-02-01

    It is not known if vitamin E in hyperlipidemia and hypercholesterolemia of longer duration has any beneficial or adverse effects on electrolytes, and liver and kidney function. The objectives of this study are to determine (i) if long duration of mild hypercholesterolemia has any adverse effects on serum electrolytes, glucose and enzymes related to liver and kidney functions; (ii) if vitamin E has any effects on serum electrolytes, glucose and enzymes related to liver and kidney function in hypercholesterolemia. Blood samples were collected from the rabbits before and at various intervals during administration of a high cholesterol diet (0.25%) for 2 and 4 months, and while on a high cholesterol diet with vitamin E following a high cholesterol diet. Measurements of serum total cholesterol (TC), glucose, aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), albumin, creatinine, electrolytes [sodium (Na), potassium (K), chloride (Cl), and carbon dioxide (CO2)] were made. High cholesterol diet for 2 months produced hypercholesterolemia which was associated with reductions in serum glucose, unaltered serum electrolytes, ALT, ALP, GGT, albumin and creatinine, and increased levels of AST. Hypercholesterolemia for 4 months had effects similar to hypercholesterolemia for 2 months except it lowered serum ALP. Vitamin E did not affect any of the parameters except serum glucose and Cl, which decreased compared to the values at month 2. Hypercholesterolemia for short and long term does not have adverse effects on liver or kidney function, and serum electrolytes. Vitamin E during hypercholesterolemia does not affect serum electrolytes or liver and kidney function.

  8. [Influence of weightlessness on water and electrolytes balance in body].

    Science.gov (United States)

    Shen, X Y

    2000-02-01

    The balance of water and electrolytes plays an important role in enabling the human body to adapt to spaceflight. This paper introduced the research methods, and changes in water and electrolytes balance during and after space flight. The mechanism and the hazard of the disorder of water and electrolytes caused by weightlessness were discussed.

  9. Vitamins

    Science.gov (United States)

    ... A Movies & More Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading ... What's in this article? Vitamins Hang Out in Water and Fat Vitamins Feed Your Needs Vitamin A ...

  10. Vitamin and water requirements of dairy sheep

    Directory of Open Access Journals (Sweden)

    Fulvia Bovera

    2010-01-01

    Full Text Available The authors review the physiological role and the daily requirement of fat-soluble vitamins (A, D, E and K, vitamin C  and water in dairy sheep. Regarding the vitamins, classical clinical symptoms and/or non-specific parameters, such as  lowered production and reproduction rates are associated with their deficiencies or excesses. Until the last decade,  these compounds were considered important only for the prevention of such alterations; currently, there is more  emphasis on their function as the vitamins can play a key role in optimising animal health. In this respect, of particu-  lar interest is the action of the antioxidant vitamins (especially vitamin C, vitamin E and beta-carotene in improving  the efficiency of the immune system. 

  11. Water and electrolytes. [in human bodies

    Science.gov (United States)

    Greenleaf, J. E.; Harrison, M. H.

    1986-01-01

    It has been found that the performance of the strongest and fittest people will deteriorate rapidly with dehydration. The present paper is concerned with the anatomy of the fluid spaces in the body, taking into account also the fluid shifts and losses during exercise and their effects on performance. Total body water is arbitrarily divided into that contained within cells (cellular) and that located outside the cells (extracellular). The anatomy of body fluid compartments is considered along with the effects of exercise on body water, fluid shifts with exercise, the consequences of sweating, dehydration and exercise, heat acclimatization and endurance training, the adverse effects of dehydration, thirst and drinking during exercise, stimuli for drinking, and water, electrolyte, and carbohydrate replacement during exercise. It is found that the deterioration of physical exercise performance due to dehydration begins when body weight decreases by about 1 percent.

  12. Water electrolyte transport through corrugated carbon nanopores.

    Science.gov (United States)

    Moghimi Kheirabadi, A; Moosavi, A

    2014-07-01

    We investigate the effect of wall roughness on water electrolyte transport characteristics at different temperatures through carbon nanotubes by using nonequilibrium molecular dynamics simulations. Our results reveal that shearing stress and the nominal viscosity increase with ion concentration in corrugated carbon nanotubes (CNTs), in contrast to cases in smooth CNTs. Also, the temperature increase leads to the reduction of shearing stress and the nominal viscosity at moderate degrees of wall roughness. At high degrees of wall roughness, the temperature increase will enhance radial movements and increases resistance against fluid motion. As the fluid velocity increases, the particles do not have enough time to fully adjust their positions to minimize system energy, which causes shearing stress and the nominal viscosity to increase. By increasing roughness amplitude or decreasing roughness wavelength, the shearing stress will increase. Synergistic effects of such parameters (wall roughness, velocity, ion concentration, and temperature) inside corrugated CNTs are studied and compared with each other. The molecular mechanisms are considered by investigating the radial density profile and the radial velocity profile of confined water inside modified CNT.

  13. [The mineral composition of the carbohydrate-electrolyte drinks, vitamin-mineral complexes and dietary supplements for athletes].

    Science.gov (United States)

    Nikitiuk, D B; Novokshanova, A L; Abrosimova, S V; Gapparova, K M; Pozdniakov, A L

    2012-01-01

    In the article analyzes the macro- and trace element composition of sports drinks, vitamin-mineral complexes and biologically active additives (BAA). The estimation of the mineral collection of these products compared with the recommended standards. Established mineral composition many of the carbohydrate-electrolyte solutions, vitamin-mineral complexes and biologically active additives corresponds the physiology standards. However in some vitamin-mineral complexes and especially biologically active additives a number of minerals can be either unreasonably low or unreasonably high. Furthermore during labeling, mainly in the category D, a number of errors were revealed. Particularly there were lack of instructions about the number of declared ingredients, inaccuracies in the calculations of the daily requirement of mineral elements etc. Providing of an athlete organism with minerals should be carried out not only by carbohydrate-electrolyte solutions, vitamin-mineral complexes and specialized BAA, but mainly through basal ration. Utilising of carbohydrate-electrolyte solutions, vitamin-mineral complexes and biologically active additives can be justified only by the recommendations of experts. This is true not only in pro sports, but for the mass sports, as well as for individual physical training, in order to maintain physically fit.

  14. Vitamins

    Directory of Open Access Journals (Sweden)

    Ruiz-Roso, Baltasar

    1998-08-01

    Full Text Available A thermal treatment is an intrinsic part of most food processing procedures and may be employed to inactive enzimes and toxic '• factors, to change texture and flavour or to preserve. The vitamin degree of transformation or destruction in cooking methods depends on the temperature and on the time of exposure to this temperature. Oxigen, light and transition metals frequently play an active role in accelerating or promoting vitamin losses. Both chemical change and difussion proceed more rapidly as the temperature is raised. An advantage of deep frying consists of the fact that the temperature within the food does not exceed the temperature of the steam under the crust, and that frying times are in general very short compared to other cooking procedures. Another advantages may be the low content of dissolved oxygen in frying fats, and also in its high tocopherol content. There is no leaching of water-soluble vitamins in deep-frying. Speaking of vitamin stability we have to keep in mind that the concept of vitamins is a more physiological concept than a chemical one. The stability itself is not a property of the various vitamins but rather of the various chemical compounds sometimes called vitamers, of which a certain vitamin group consists. For practical purposes, vitamin losses should be considered only in foods wich substantially contribute to the vitamin supply of single people or population groups. There is little data in the literature about vitamin changes in deep-frying of food. However published experimental data on vitamin loses show that deep-frying is one of the most protective cooking procedures. For example, in ours results the vitamin C losses of stewed vegetable foods were twice higher than that of fried ones, (raw potatoes containing 19 mg/100g fresh weight, 13 mg/100 fried in olive oil, and 5 mg/100g stewed in the same oil.

  15. ELectrolytes,water,acid—base imbalance

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930044 The effect of dilution and heparin onthe blood gas analysis.JIANG Hongxi(蒋鸿鑫)et al.Beijing Friendship Hosp,Beijing,100050.Chin J Tubere & Respri Dis 1992;15(4):225-227.The effect of heparin on the measurement ofblood gases is mainly caused by dilution,whichsubstantially reduces the PCO2 and HCO3- val-ues.Excess heparin will change the pH,PCO2and HCO3- as a consequence of an alternation inH+ ion concentration.The effect of dilution onelectrolytes depends on the respective elec-trolyte concentration in diluent.Dilution re-duces the glucose value,but to a higher degreeas could be expected from a dilution effect.

  16. Novel Ceramic Materials for Polymer Electrolyte Membrane Water Electrolysers' Anodes

    DEFF Research Database (Denmark)

    Polonsky, J.; Bouzek, K.; Prag, Carsten Brorson

    2012-01-01

    Tantalum carbide was evaluated as a possible new support for the IrO2 for use in anodes of polymer electrolyte membrane water electrolysers. A series of supported electrocatalysts varying in mass content of iridium oxide was prepared. XRD, powder conductivity measurements and cyclic and linear sw...

  17. Urinary water-soluble vitamins and their metabolite contents as nutritional markers for evaluating vitamin intakes in young Japanese women.

    Science.gov (United States)

    Fukuwatari, Tsutomu; Shibata, Katsumi

    2008-06-01

    Little information is available to estimate water-soluble vitamin intakes from urinary vitamins and their metabolite contents as possible nutritional markers. Determination of the relationships between the oral dose and urinary excretion of water-soluble vitamins in human subjects contributes to finding valid nutrition markers of water-soluble vitamin intakes. Six female Japanese college students were given a standard Japanese diet in the first week, the same diet with a synthesized water-soluble vitamin mixture as a diet with approximately onefold vitamin mixture based on Dietary Reference Intakes (DRIs) for Japanese in the second week, with a threefold vitamin mixture in the third week, and a sixfold mixture in the fourth week. Water-soluble vitamins and their metabolites were measured in the 24-h urine collected each week. All urinary vitamins and their metabolite levels except vitamin B(12) increased linearly in a dose-dependent manner, and highly correlated with vitamin intake (r=0.959 for vitamin B(1), r=0.927 for vitamin B(2), r=0.965 for vitamin B(6), r=0.957 for niacin, r=0.934 for pantothenic acid, r=0.907 for folic acid, r=0.962 for biotin, and r=0.952 for vitamin C). These results suggest that measuring urinary water-soluble vitamins and their metabolite levels can be used as good nutritional markers for assessing vitamin intakes.

  18. Distribution of Tissue Water and Electrolytes in Normal Rhesus Macaques.

    Science.gov (United States)

    1978-03-02

    reported for hyperthermia, 26 deoxycorticosterone acetate administration,1’3 hypocalcemic tetany)’6 respiratory acidosis and alkalosis , 27’28 and...continuing respiratory work performed by the diaphragm of monkeys. As a rule, values for tissue intracellular water should be greater than those of...C. B., and Lamber t , H.: Card iac and Skeletal Muscle Electrolytes In Acute Respiratory Alkalemia and Acidemia. J Appl Physiol , 15, (1960): 459

  19. Determination of water-soluble vitamins in soft drinks and vitamin supplements using capillary electrophoresis.

    Science.gov (United States)

    Schreiner, Matthias; Razzazi, Ebrahim; Luf, Wolfgang

    2003-08-01

    A method for the determination of six water-soluble vitamins based on capillary electrophoresis (CE) operated in micellar mode was developed. Thiamine hydrochloride (vitamin B1), riboflavin (vitamin B2), pyridoxine hydrochloride (vitamin B6), pantothenic acid (vitamin B5), nicotinamide (vitamin B3), and cobalamin (Vitamin B12) could be separated in a single run. All CE parameters such as buffer composition and operation temperature were optimized in order to achieve better separation. Relative standard deviations (RSDs) of the described method ranged from 1.08 to 3.68% (intra-day precision) and 1.26 to 3.35% (inter-day precision). The method was then used for measuring various soft drinks and vitamin supplements directly without any step of sample cleanup. The determination of niacin was successful for all samples tested, reaching recoveries near 100%. Riboflavin and pyridoxine were quantified successfully in some but not all samples. Therefore, an evaluation on a case-by-case basis is mandatory. When applicable, this method provides a fast, accurate, simple, and inexpensive way to quantify selected vitamins, and is therefore well suited for routine analysis in soft drink industry.

  20. Plasma concentrations of water-soluble vitamins in metabolic ...

    African Journals Online (AJOL)

    2012-01-21

    Jan 21, 2012 ... levels of water-soluble vitamins with metabolic syndrome and its various components. Aims: This ... thiamine has a role in reducing cellular oxidative stress.[2,12] ... a protective effect on pancreatic beta-cell survival, probably.

  1. Polymer Electrolyte Membranes for Water Photo-Electrolysis

    Science.gov (United States)

    Aricò, Antonino S.; Girolamo, Mariarita; Siracusano, Stefania; Sebastian, David; Baglio, Vincenzo; Schuster, Michael

    2017-01-01

    Water-fed photo-electrolysis cells equipped with perfluorosulfonic acid (Nafion® 115) and quaternary ammonium-based (Fumatech® FAA3) ion exchange membranes as separator for hydrogen and oxygen evolution reactions were investigated. Protonic or anionic ionomer dispersions were deposited on the electrodes to extend the interface with the electrolyte. The photo-anode consisted of a large band-gap Ti-oxide semiconductor. The effect of membrane characteristics on the photo-electrochemical conversion of solar energy was investigated for photo-voltage-driven electrolysis cells. Photo-electrolysis cells were also studied for operation under electrical bias-assisted mode. The pH of the membrane/ionomer had a paramount effect on the photo-electrolytic conversion. The anionic membrane showed enhanced performance compared to the Nafion®-based cell when just TiO2 anatase was used as photo-anode. This was associated with better oxygen evolution kinetics in alkaline conditions compared to acidic environment. However, oxygen evolution kinetics in acidic conditions were significantly enhanced by using a Ti sub-oxide as surface promoter in order to facilitate the adsorption of OH species as precursors of oxygen evolution. However, the same surface promoter appeared to inhibit oxygen evolution in an alkaline environment probably as a consequence of the strong adsorption of OH species on the surface under such conditions. These results show that a proper combination of photo-anode and polymer electrolyte membrane is essential to maximize photo-electrolytic conversion. PMID:28468242

  2. Carbohydrate-Electrolyte Characteristics of Coconut Water from Different Varieties and Its Potential as Natural Isotonic Drink

    Directory of Open Access Journals (Sweden)

    Sari Intan Kailaku

    2015-01-01

    Full Text Available Coconut water is known as a nutritious natural drink. It is not only considered functional, but also nutraceutical. Coconut water is widely used as isotonic drink or oral rehydration fluid, since it showed excellent rehydration index and blood glucose response in previous researches. The quality of isotonic drink is determined by its sugar content (as the source of carbohydrate and electrolyte content. Moreover, its organoleptic properties should be able to stimulate the urge to spontaniously drink more. However, the processing of coconut water into isotonic drink usually applies ultra high or very low temperature which might deteriorate its nutrition value and organoleptic properties, causing the needs to use a considerable amount of food additives. There are plenty varieties of coconut in Indonesia, each produces different characteristics of coconut water. The objectives of this research are to compare the carbohydrate-electrolyte characteristics of coconut water, and also other essential characteristics from several varieties and to determine which variety is closest to the quality standard of isotonic drink. Therefore, isotonic drink can be developed with only minimum food additives.  We compared Dalam Pangandaran, Genjah Salak and Hybrid PB121. The characteristics observed were total sugar, sucrose, glucose, fructose, potassium, sodium, magnesium, vitamin B1, vitamin B6 and vitamin C content, as well as pH, total soluble solids, clarity and colour. Coconut water obatined from Genjah (Dwarf variety showed the more suitable characteristics for the development of isotonic drink. Thus the product can be developed by cold sterilitation process with minimum food additives. 

  3. PREDICTING WATER ACTIVITY IN ELECTROLYTE SOLUTIONS WITH THE CISTERNAS-LAM MODEL

    Energy Technology Data Exchange (ETDEWEB)

    REYNOLDS JG; GREER DA; DISSELKAMP RL

    2011-03-01

    Water activity is an important parameter needed to predict the solubility of hydrated salts in Hanford nuclear waste supernatants. A number of models available in the scientific literature predict water activity from electrolyte solution composition. The Cisternas-Lam model is one of those models and has several advantages for nuclear waste application. One advantage is that it has a single electrolyte specific parameter that is temperature independent. Thus, this parameter can be determined from very limited data and extrapolated widely. The Cisternas-Lam model has five coefficients that are used for all aqueous electrolytes. The present study aims to determine if there is a substantial improvement in making all six coefficients electrolyte specific. The Cisternas-Lam model was fit to data for six major electrolytes in Hanford nuclear waste supernatants. The model was first fit to all data to determine the five global coefficients, when they were held constant for all electrolytes it yielded a substantially better fit. Subsequently, the model was fit to each electrolyte dataset separately, where all six coefficients were allowed to be electrolyte specific. Treating all six coefficients as electrolyte specific did not make sufficient difference, given the complexity of applying the electrolyte specific parameters to multi-solute systems. Revised water specific parameters, optimized to the electrolytes relevant to Hanford waste, are also reported.

  4. ABOUT PHYSICOCHEMICAL PROCESSES AT ELECTROLYTIC DECOMPOZITION OF THE WATER

    Directory of Open Access Journals (Sweden)

    Berzan V.P.

    2006-04-01

    Full Text Available Physical processes are investigated at electrolyze waters from the power point of view at small density of a current.Reception of hydrogen is possible not only at the well-known charge of the electric power exceeding energy which can be received at burning this hydrogen (about 12 MJ/m3, but under some conditions and at the smaller charge of the electric power. The minimal density of a current (10 А/m2 is determined at which restoration of ions of gases occurs in the energy-economic way, and also value of density of a current (107А/m2 at which in a solution of electrolyte begin plasma discharges.It is experimentally shown, that if the condition of maintenance of the minimal density of a current is carried out only on one electrode also liberation of gas occurs on it as short-term transient. The kind of this gas (hydrogen or oxygen is determined by polarity of a supplay of electrolitical cell. Values of a voltage at which gas on electrodes is not recepted are experimentally determined, is receipt on one electrode and gas starts will be receipt on both electrodes of a cell.Processes which existence it is possible to explain only passage electrons through electrolyte are revealed as well.

  5. Modelling electrolyte conductivity in a water electrolyzer cell

    DEFF Research Database (Denmark)

    Caspersen, Michael; Kirkegaard, Julius Bier

    2012-01-01

    An analytical model describing the hydrogen gas evolution under natural convection in an electrolyzer cell is developed. Main purpose of the model is to investigate the electrolyte conductivity through the cell under various conditions. Cell conductivity is calculated from a parallel resistor app...... for electrolyte conductivity from combinations of pressure, current density and electrolyte width among others....

  6. Electrocatalysis in Water Electrolysis with Solid Polymer Electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Rasten, Egil

    2001-10-01

    Development and optimization of the electrodes in a water electrolysis system using a polymer membrane as electrolyte have been carried out in this work. A cell voltage of 1.59 V (energy consumption of about 3.8 kWh/Nm{sub 3} H{sub 2}) has been obtained at practical operation conditions of the electrolysis cell (10 kA . m2, 90{sup o}C) using a total noble metal loading of less than 2.4 mg.cm{sub 2} and a Nafion -115 membrane. It is further shown that a cell voltage of less than 1.5 V is possible at the same conditions by combination of the best electrodes obtained in this work. The most important limitation of the electrolysis system using polymer membrane as electrolyte has proven to be the electrical conductivity of the catalysts due to the porous backing/current collector system, which increases the length of the current path and decreases the cross section compared to the apparent one. A careful compromise must therefore be obtained between electrical conductivity and active surface area, which can be tailored by preparation and annealing conditions of the metal oxide catalysts. Anode catalysts of different properties have been developed. The mixed oxide of Ir-Ta (85 mole% Ir) was found to exhibit highest voltage efficiency at a current density of 10 kA.m{sub 2} or below, whereas the mixed oxide of Ir and Ru (60-80 mole% Ir) was found to give the highest voltage efficiency for current densities of above 10 kA.m{sub 2}. Pt on carbon particles, was found to be less suitable as cathode catalyst in water electrolysis. The large carbon particles introduced an unnecessary porosity into the catalytic layer, which resulted in a high ohmic drop. Much better voltage efficiency was obtained by using Pt-black as cathode catalyst, which showed a far better electrical conductivity. Ru-oxide as cathode catalyst in water electrolysis systems using a polymer electrolyte was not found to be of particular interest due to insufficient electrochemical activity and too low

  7. Development of solid electrolytes for water electrolysis at higher temperature

    Energy Technology Data Exchange (ETDEWEB)

    Linkous, C.A. [Florida Solar Energy Center, Cocoa, FL (United States)

    1996-10-01

    This report describes efforts in developing new solid polymer electrolytes that will enable operation of proton exchange membrane electrolyzers at higher temperatures than are currently possible. Several ionomers have been prepared from polyetheretherketone (PEEK), polyethersulfone (PES), and polyphenylquinoxaline (PPQ) by employing various sulfonation procedures. By controlling the extent of sulfonation, a range of proton conductivities could be achieved, whose upper limit actually exceeded that of commercially available perfluoralkyl sulfonates. Thermoconductimetric analysis of samples at various degrees of sulfonation showed an inverse relationship between conductivity and maximum operating temperature. This was attributed to the dual effect of adding sulfonate groups to the polymer: more acid groups produce more protons for increased conductivity, but they also increase water uptake, which mechanically weakens the membrane. This situation was exacerbated by the limited acidity of the aromatic sulfonic acids (pK{sub A} {approx} 2-3). The possibility of using partial fluorination to raise the acid dissociation constant is discussed.

  8. Composition and particle size of electrolytic copper powders prepared in water-containing dimethyl sulfoxide electrolytes

    Science.gov (United States)

    Mamyrbekova, Aigul'; Abzhalov, B. S.; Mamyrbekova, Aizhan

    2017-07-01

    The possibility of the electroprecipitation of copper powder via the cathodic reduction of an electrolyte solution containing copper(II) nitrate trihydrate and dimethyl sulfoxide (DMSO) is shown. The effect electrolysis conditions (current density, concentration and temperature of electrolyte) have on the dimensional characteristics of copper powder is studied. The size and shape of the particles of the powders were determined by means of electron microscopy; the qualitative composition of the powders, with X-ray diffraction.

  9. Towards versatile and sustainable hydrogen production via electrocatalytic water splitting: Electrolyte engineering

    KAUST Repository

    Shinagawa, Tatsuya

    2016-12-17

    Recent advances in power generation from renewable resources necessitate conversion of electricity to chemicals and fuels in an efficient manner. The electrocatalytic water splitting is one of the most powerful and widespread technologies. The development of highly efficient, inexpensive, flexible and versatile water electrolysis devices is desired. This review discusses the significance and impact of the electrolyte on electrocatalytic performance. Depending on the circumstances where water splitting reaction is conducted, required solution conditions such as the identity and molarity of ions may significantly differ. Quantitative understanding of such electrolyte properties on electrolysis performance is effective to facilitate developing efficient electrocatalytic systems. The electrolyte can directly participate in reaction schemes (kinetics), electrode stability, and/or indirectly impacts the performance by influencing concentration overpotential (mass transport). This review aims to guide fine-tuning of the electrolyte properties, or electrolyte engineering, for (photo)electrochemical water splitting reactions.

  10. Automatic devices for electrochemical water treatment with cooling of electrolyte

    Directory of Open Access Journals (Sweden)

    Trišović Tomislav Lj.

    2016-01-01

    Full Text Available The most common disinfectants for water treatment are based on chlorine and its compounds. Practically, water treatments with chlorine compounds have no alternative, since they provide, in comparison to other effective processes such as ozonization or ultraviolet irradiation, high residual disinfection capacity. Unfortunately, all of chlorine-based compounds for disinfection tend to degrade during storage, thus reducing the concentration of active chlorine. Apart from degradation, additional problems are transportation, storage and handling of such hazardous compounds. Nowadays, a lot of attention is paid to the development of electrochemical devices for in situ production of chlorine dioxide or sodium hypochlorite as efficient disinfectants for water treatment. The most important part of such a device is the electrochemical reactor. Electrochemical reactor uses external source of direct current in order to produce disinfectants in electrochemical reactions occurring at the electrodes. Construction of an electrochemical device for water treatment is based on evaluation of optimal conditions for electrochemical reactions during continues production of disinfectants. The aim of this study was to develop a low-cost electrochemical device for the production of disinfectant, active chlorine, at the place of its usage, based on newly developed technical solutions and newest commercial components. The projected electrochemical device was constructed and mounted, and its operation was investigated. Investigations involved both functionality of individual components and device in general. The major goal of these investigations was to achieve maximal efficiency in extreme condition of elevated room temperature and humidity with a novel device construction involving coaxial heat exchanger at the solution inlet. Room operation of the proposed device was investigated when relative humidity was set to 90% and the ambient temperature of 38°C. The obtained

  11. Water-based thixotropic polymer gel electrolyte for dye-sensitized solar cells.

    Science.gov (United States)

    Park, Se Jeong; Yoo, Kichoen; Kim, Jae-Yup; Kim, Jin Young; Lee, Doh-Kwon; Kim, Bongsoo; Kim, Honggon; Kim, Jong Hak; Cho, Jinhan; Ko, Min Jae

    2013-05-28

    For the practical application of dye-sensitized solar cells (DSSCs), it is important to replace the conventional organic solvents based electrolyte with environmentally friendly and stable ones, due to the toxicity and leakage problems. Here we report a noble water-based thixotropic polymer gel electrolyte containing xanthan gum, which satisfies both the environmentally friendliness and stability against leakage and water intrusion. For application in DSSCs, it was possible to infiltrate the prepared electrolyte into the mesoporous TiO2 electrode at the fluidic state, resulting in sufficient penetration. As a result, this electrolyte exhibited similar conversion efficiency (4.78% at 100 mW cm(-2)) and an enhanced long-term stability compared to a water-based liquid electrolyte. The effects of water on the photovoltaic properties were examined elaborately from the cyclic voltammetry curves and impedance spectra. Despite the positive shift in the conduction band potential of the TiO2 electrode, the open-circuit voltage was enhanced by addition of water in the electrolyte due to the greater positive shift in the I(-)/I3(-) redox potential. However, due to the dye desorption and decreased diffusion coefficient caused by the water content, the short-circuit photocurrent density was reduced. These results will provide great insight into the development of efficient and stable water-based electrolytes.

  12. Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest

    Directory of Open Access Journals (Sweden)

    T. Raatikainen

    2005-01-01

    Full Text Available In this work, existing and modified activity coefficient models are examined in order to assess their capabilities to describe the properties of aqueous solution droplets relevant in the atmosphere. Five different water-organic-electrolyte activity coefficient models were first selected from the literature. Only one of these models included organics and electrolytes which are common in atmospheric aerosol particles. In the other models, organic species were solvents such as alcohols, and important atmospheric ions like NH4+ could be missing. The predictions of these models were compared to experimental activity and solubility data in aqueous single electrolyte solutions with 31 different electrolytes. Based on the deviations from experimental data and on the capabilities of the models, four predictive models were selected for fitting of new parameters for binary and ternary solutions of common atmospheric electrolytes and organics. New electrolytes (H+, NH4+, Na+, Cl-, NO3- and SO42- and organics (dicarboxylic and some hydroxy acids were added and some modifications were made to the models if it was found useful. All new and most of the existing parameters were fitted to experimental single electrolyte data as well as data for aqueous organics and aqueous organic-electrolyte solutions. Unfortunately, there are very few data available for organic activities in binary solutions and for organic and electrolyte activities in aqueous organic-electrolyte solutions. This reduces model capabilities in predicting solubilities. After the parameters were fitted, deviations from measurement data were calculated for all fitted models, and for different data types. These deviations and the calculated property values were compared with those from other non-electrolyte and organic-electrolyte models found in the literature. Finally, hygroscopic growth factors were calculated for four 100 nm organic-electrolyte particles and these predictions were compared to

  13. Nanometer-scale water- and proton-diffusion heterogeneities across water channels in polymer electrolyte membranes.

    Science.gov (United States)

    Song, Jinsuk; Han, Oc Hee; Han, Songi

    2015-03-16

    Nafion, the most widely used polymer for electrolyte membranes (PEMs) in fuel cells, consists of a fluorocarbon backbone and acidic groups that, upon hydration, swell to form percolated channels through which water and ions diffuse. Although the effects of the channel structures and the acidic groups on water/ion transport have been studied before, the surface chemistry or the spatially heterogeneous diffusivity across water channels has never been shown to directly influence water/ion transport. By the use of molecular spin probes that are selectively partitioned into heterogeneous regions of the PEM and Overhauser dynamic nuclear polarization relaxometry, this study reveals that both water and proton diffusivity are significantly faster near the fluorocarbon and the acidic groups lining the water channels than within the water channels. The concept that surface chemistry at the (sub)nanometer scale dictates water and proton diffusivity invokes a new design principle for PEMs.

  14. [Nutrition and bone health. The bone and the foods containing many water-soluble vitamins].

    Science.gov (United States)

    Ishida, Hiromi

    2009-08-01

    On the Dietary Reference Intakes in Japan, nine kinds of water-soluble vitamins are taken up. Those vitamins are supplied from various food. Food from animal sources and vegetable sources are those vitamins source of supply. Vitamin C participates in generation of collagen. Vitamin C is supplied from vegetables or fruits. Since vitamin C is lost by cooking processing, the content of a raw state is not expectable after cooking. Moreover, the vitamin B group of food origin has combined with protein etc., and free types, such as supplement, differ in the bioavailability.

  15. Vitamins

    Science.gov (United States)

    ... health problems, including heart disease, cancer, and poor bone health ( osteoporosis ). Vitamin A helps form and maintain healthy teeth, bones, soft tissue, mucus membranes, and skin. Vitamin B6 ...

  16. Treatment of alternated water-electrolyte balance and endocrine status after removal of craniopharyngioma in adults

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; ZHAO Shang-feng; ZHANG Wei; ZHANG Mao-zhi

    2006-01-01

    Background Water-electrolyte disturbance and endocrine alterations are common complications of adult patients with craniopharygioma in the postoperative period and may affect their recovery and prognosis. Some of these complications even lead to death. Appropriate remedy based upon the status of water-electrolyte balance and the endocrine system is essential to good therapeutic results of adult patients with craniopharyngioma.Methods The alterations in water-electrolyte balance (117 patients) and endocrine status (42) of adult patients with craniopharyngioma after surgery were analyzed retrospectively.Results Most patients with craniopharyngioma experienced postoperative water-electrolyte disturbances and hypotonic dehydration. Moreover, the incidences of hypothyroidism and hypoadrenocorticism were relatively high.Conclusion It is critical to deal with dehydration and endocrine disorders for a sound outcome of craniopharyngioma surgery.

  17. Towards a stable ion-solvating polymer electrolyte for advanced alkaline water electrolysis

    DEFF Research Database (Denmark)

    Aili, David; Wright, Andrew G.; Kraglund, Mikkel Rykær

    2017-01-01

    Advanced alkaline water electrolysis using ion-solvating polymer membranes as electrolytes represents a new direction in the field of electrochemical hydrogen production. Polybenzimidazole membranes equilibrated in aqueous KOH combine the mechanical robustness and gas-tightness of a polymer...

  18. Water Transport Analysis in Polymer Electrolyte Membrane Fuel Cells by Magnetic Resonance Imaging

    Institute of Scientific and Technical Information of China (English)

    S.Tsushima; S.Hirai

    2007-01-01

    1 Results Polymer electrolyte fuel cells (PEFCs) have beenintensively developedfor future vehicle applications andon-site power generation owing to its high energy efficiency and high power density.In PEFCs ,appropriatewater management to maintain polymer electrolyte membrane (PEM) hydratedis of great i mportance ,becausethe ion conductivity of membraneislower at lower water content .Consequently,it is of great interest to watercontent and water transport process in PEMs during fuel cell operation.

  19. Electrolytic exfoliation of graphite in water with multifunctional electrolytes: en route towards high quality, oxide-free graphene flakes.

    Science.gov (United States)

    Munuera, J M; Paredes, J I; Villar-Rodil, S; Ayán-Varela, M; Martínez-Alonso, A; Tascón, J M D

    2016-02-07

    Electrolytic--usually referred to as electrochemical--exfoliation of graphite in water under anodic potential holds enormous promise as a simple, green and high-yield method for the mass production of graphene, but currently suffers from several drawbacks that hinder its widespread adoption, one of the most critical being the oxidation and subsequent structural degradation of the carbon lattice that is usually associated with such a production process. To overcome this and other limitations, we introduce and implement the concept of multifunctional electrolytes. The latter are amphiphilic anions (mostly polyaromatic hydrocarbons appended with sulfonate groups) that play different relevant roles as (1) an intercalating electrolyte to trigger exfoliation of graphite into graphene flakes, (2) a dispersant to afford stable aqueous colloidal suspensions of the flakes suitable for further use, (3) a sacrificial agent to prevent graphene oxidation during exfoliation and (4) a linker to promote nanoparticle anchoring on the graphene flakes, yielding functional hybrids. The implementation of this strategy with some selected amphiphiles even furnishes anodically exfoliated graphenes of a quality similar to that of flakes produced by direct, ultrasound- or shear-induced exfoliation of graphite in the liquid phase (i.e., almost oxide- and defect-free). These high quality materials were used for the preparation of catalytically efficient graphene-Pt nanoparticle hybrids, as demonstrated by model reactions (reduction of nitroarenes). The multifunctional performance of these electrolytes is also discussed and rationalized, and a mechanistic picture of their oxidation-preventing ability is proposed. Overall, the present results open the prospect of anodic exfoliation as a competitive method for the production of very high quality graphene flakes.

  20. Electrolytic exfoliation of graphite in water with multifunctional electrolytes: en route towards high quality, oxide-free graphene flakes

    Science.gov (United States)

    Munuera, J. M.; Paredes, J. I.; Villar-Rodil, S.; Ayán-Varela, M.; Martínez-Alonso, A.; Tascón, J. M. D.

    2016-01-01

    Electrolytic - usually referred to as electrochemical - exfoliation of graphite in water under anodic potential holds enormous promise as a simple, green and high-yield method for the mass production of graphene, but currently suffers from several drawbacks that hinder its widespread adoption, one of the most critical being the oxidation and subsequent structural degradation of the carbon lattice that is usually associated with such a production process. To overcome this and other limitations, we introduce and implement the concept of multifunctional electrolytes. The latter are amphiphilic anions (mostly polyaromatic hydrocarbons appended with sulfonate groups) that play different relevant roles as (1) an intercalating electrolyte to trigger exfoliation of graphite into graphene flakes, (2) a dispersant to afford stable aqueous colloidal suspensions of the flakes suitable for further use, (3) a sacrificial agent to prevent graphene oxidation during exfoliation and (4) a linker to promote nanoparticle anchoring on the graphene flakes, yielding functional hybrids. The implementation of this strategy with some selected amphiphiles even furnishes anodically exfoliated graphenes of a quality similar to that of flakes produced by direct, ultrasound- or shear-induced exfoliation of graphite in the liquid phase (i.e., almost oxide- and defect-free). These high quality materials were used for the preparation of catalytically efficient graphene-Pt nanoparticle hybrids, as demonstrated by model reactions (reduction of nitroarenes). The multifunctional performance of these electrolytes is also discussed and rationalized, and a mechanistic picture of their oxidation-preventing ability is proposed. Overall, the present results open the prospect of anodic exfoliation as a competitive method for the production of very high quality graphene flakes.Electrolytic - usually referred to as electrochemical - exfoliation of graphite in water under anodic potential holds enormous promise

  1. Direct simulation of liquid water dynamics in the gas channel of a polymer electrolyte fuel cell

    NARCIS (Netherlands)

    Qin, C.; Rensink, D.; Hassanizadeh, S.M.; Fell, S.

    2012-01-01

    For better water management in gas channels (GCs) of polymer electrolyte fuel cells (PEFCs), a profound understanding of the liquid water dynamics is needed. In this study, we propose a novel geometrical setup to conduct a series of direct simulations of the liquid water dynamics in a GC. The conduc

  2. Subchronic Arsenic Exposure Through Drinking Water Alters Lipid Profile and Electrolyte Status in Rats.

    Science.gov (United States)

    Waghe, Prashantkumar; Sarkar, Souvendra Nath; Sarath, Thengumpallil Sasindran; Kandasamy, Kannan; Choudhury, Soumen; Gupta, Priyanka; Harikumar, Sankarankutty; Mishra, Santosh Kumar

    2017-04-01

    Arsenic is a groundwater pollutant and can cause various cardiovascular disorders in the exposed population. The aim of the present study was to assess whether subchronic arsenic exposure through drinking water can induce vascular dysfunction associated with alteration in plasma electrolytes and lipid profile. Rats were exposed to arsenic as 25, 50, and 100 ppm of sodium arsenite through drinking water for 90 consecutive days. On the 91st day, rats were sacrificed and blood was collected. Lipid profile and the levels of electrolytes (sodium, potassium, and chloride) were assessed in plasma. Arsenic reduced high-density lipoprotein cholesterol (HDL-C) and HDL-C/LDL-C ratio, but increased the levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-C), and electrolytes. The results suggest that the arsenic-mediated dyslipidemia and electrolyte retention could be important mechanisms in the arsenic-induced vascular disorder.

  3. Urinary excretion of water-soluble vitamins increases in streptozotocin-induced diabetic rats without decreases in liver or blood vitamin content.

    Science.gov (United States)

    Imai, Eri; Sano, Mitsue; Fukuwatari, Tsutomu; Shibata, Katsumi

    2012-01-01

    It is thought that the contents of water-soluble vitamins in the body are generally low in diabetic patients because large amounts of vitamins are excreted into urine. However, this hypothesis has not been confirmed. To investigate this hypothesis, diabetes was induced in male Wistar rats (6 wk old) by streptozotocin treatment, and they were then given diets containing low, medium or sufficient vitamins for 70 d. The contents of 6 kinds of B-group vitamins, namely vitamin B₁, vitamin B₂, vitamin B₆, vitamin B₁₂, folate and biotin, were determined in the urine, blood and liver. No basic differences among the dietary vitamin contents were observed. The urinary excretion of vitamins was higher in diabetic rats than in control rats. The blood concentrations of vitamin B₁₂ and folate were lowered by diabetes, while, those of vitamin B₁, vitamin B₂, vitamin B₆, and biotin were not. All liver concentrations of vitamins were increased in diabetic rats above those in control rats. These results showed that streptozotocin-induced diabetes increased urinary excretion of water-soluble vitamins, though their blood and liver concentrations were essentially maintained in the rats.

  4. Electrical conductivity of electrolytes applicable to natural waters from 0 to 100 degrees C

    Science.gov (United States)

    McCleskey, R. Blaine

    2011-01-01

    The electrical conductivities of 34 electrolyte solutions found in natural waters ranging from (10-4 to 1) mol•kg-1 in concentration and from (5 to 90) °C have been determined. High-quality electrical conductivity data for numerous electrolytes exist in the scientific literature, but the data do not span the concentration or temperature ranges of many electrolytes in natural waters. Methods for calculating the electrical conductivities of natural waters have incorporated these data from the literature, and as a result these methods cannot be used to reliably calculate the electrical conductivity over a large enough range of temperature and concentration. For the single-electrolyte solutions, empirical equations were developed that relate electrical conductivity to temperature and molality. For the 942 molar conductivity determinations for single electrolytes from this study, the mean relative difference between the calculated and measured values was 0.1 %. The calculated molar conductivity was compared to literature data, and the mean relative difference for 1978 measurements was 0.2 %. These data provide an improved basis for calculating electrical conductivity for most natural waters.

  5. Towards Versatile and Sustainable Hydrogen Production through Electrocatalytic Water Splitting: Electrolyte Engineering.

    Science.gov (United States)

    Shinagawa, Tatsuya; Takanabe, Kazuhiro

    2017-04-10

    Recent advances in power generation from renewable resources necessitate conversion of electricity to chemicals and fuels in an efficient manner. Electrocatalytic water splitting is one of the most powerful and widespread technologies. The development of highly efficient, inexpensive, flexible, and versatile water electrolysis devices is desired. This review discusses the significance and impact of the electrolyte on electrocatalytic performance. Depending on the circumstances under which the water splitting reaction is conducted, the required solution conditions, such as the identity and molarity of ions, may significantly differ. Quantitative understanding of such electrolyte properties on electrolysis performance is effective to facilitate the development of efficient electrocatalytic systems. The electrolyte can directly participate in reaction schemes (kinetics), affect electrode stability, and/or indirectly impact the performance by influencing the concentration overpotential (mass transport). This review aims to guide fine-tuning of the electrolyte properties, or electrolyte engineering, for (photo)electrochemical water splitting reactions. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  6. Solvent activities of the fluorinated solid polymer electrolyte/water system in fuel cells

    Science.gov (United States)

    Kim, Tae Hwan; Bae, Young Chan

    We modified the lattice fluid equation-of-state by the introducing Debye-Hückel equation. A thermodynamic model taking into account the specific interaction and ionic strength between the polymer and the solvent is proposed. The proposed model successfully predicts the vapor/liquid equilibria (VLE) of solvents and the solid polymer electrolyte (SPE). A generalized lattice fluid model is modified to describe the change of water activity in solid polymer electrolyte (SPE)/water systems. The calculated activity curves using the proposed model agree remarkably well with the experimental data.

  7. Urinary excretion levels of water-soluble vitamins in pregnant and lactating women in Japan.

    Science.gov (United States)

    Shibata, Katsumi; Fukuwatari, Tsutomu; Sasaki, Satoshi; Sano, Mitsue; Suzuki, Kahoru; Hiratsuka, Chiaki; Aoki, Asami; Nagai, Chiharu

    2013-01-01

    Recent studies have shown that the urinary excretion levels of water-soluble vitamins can be used as biomarkers for the nutritional status of these vitamins. To determine changes in the urinary excretion levels of water-soluble vitamins during pregnant and lactating stages, we surveyed and compared levels of nine water-soluble vitamins in control (non-pregnant and non-lactating women), pregnant and lactating women. Control women (n=37), women in the 2nd (16-27 wk, n=24) and 3rd trimester of pregnancy (over 28 wk, n=32), and early- (0-5 mo, n=54) and late-stage lactating (6-11 mo, n=49) women took part in the survey. The mean age of subjects was ~30 y, and mean height was ~160 cm. A single 24-h urine sample was collected 1 d after the completion of a validated, self-administered comprehensive diet history questionnaire to measure water-soluble vitamins or metabolites. The average intake of each water-soluble vitamin was ≍ the estimated average requirement value and adequate intake for the Japanese Dietary Reference Intakes in all life stages, except for vitamin B6 and folate intakes during pregnancy. No change was observed in the urinary excretion levels of vitamin B2, vitamin B6, vitamin B12, biotin or vitamin C among stages. Urine nicotinamide and folate levels were higher in pregnant women than in control women. Urine excretion level of vitamin B1 decreased during lactation and that of pantothenic acid decreased during pregnancy and lactation. These results provide valuable information for setting the Dietary Reference Intakes of water-soluble vitamins for pregnant and lactating women.

  8. High resolution neutron imaging of water in the polymer electrolyte fuel cell membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Partha P [Los Alamos National Laboratory; Makundan, Rangachary [Los Alamos National Laboratory; Spendelow, Jacob S [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Hussey, D S [NIST; Jacobson, D L [NIST; Arif, M [NIST

    2009-01-01

    Water transport in the ionomeric membrane, typically Nafion{reg_sign}, has profound influence on the performance of the polymer electrolyte fuel cell, in terms of internal resistance and overall water balance. In this work, high resolution neutron imaging of the Nafion{reg_sign} membrane is presented in order to measure water content and through-plane gradients in situ under disparate temperature and humidification conditions.

  9. Acute and chronic effects of growth hormone on renal regulation of electrolyte and water homeostasis.

    NARCIS (Netherlands)

    Dimke, H.; Flyvbjerg, A.; Frische, S.

    2007-01-01

    For decades, growth hormone (GH) has been known to influence electrolyte and water handling in humans and animals. However, the molecular mechanisms underlying the GH-induced anti-natriuretic and anti-diuretic effects have remained elusive. This review will examine the existing literature on renal e

  10. Numerical studies on liquid water flooding in gas channels used inpolymer electrolyte fuel cells

    NARCIS (Netherlands)

    Qin, CZ.; Hassanizadeh, S.M.; Rensink, D.

    2012-01-01

    Water management plays an important role in the development of low-temperature polymer electrolyte fuel cells (PEFCs). The lack of a macroscopic gas channel (GC) flooding model constrains the current predictions of PEFC modeling under severe flooding situations. In this work, we have extended our pr

  11. Small angle neutron scattering data of polymer electrolyte membranes partially swollen in water

    Directory of Open Access Journals (Sweden)

    Yue Zhao

    2016-06-01

    Full Text Available In this article, we show the small-angle neutron scattering (SANS data obtained from the polymer electrolyte membranes (PEMs equilibrated at a given relative humidity. We apply Hard-Sphere (HS structure model with Percus–Yervick interference interactions to analyze the dataset. The molecular structure of these PEMs and the morphologies of the fully water-swollen membranes have been elucidated by Zhao et al. “Elucidation of the morphology of the hydrocarbon multi-block copolymer electrolyte membranes for proton exchange fuel cells” [1].

  12. A Review of Water Management in Polymer Electrolyte Membrane Fuel Cells

    OpenAIRE

    2009-01-01

    At present, despite the great advances in polymer electrolyte membrane fuel cell (PEMFC) technology over the past two decades through intensive research and development activities, their large-scale commercialization is still hampered by their higher materials cost and lower reliability and durability. In this review, water management is given special consideration. Water management is of vital importance to achieve maximum performance and durability from PEMFCs. On the one hand, to maintain ...

  13. On the Diffusion Coefficient of Water in Polymer Electrolyte Membranes

    DEFF Research Database (Denmark)

    Olesen, Anders Christian; Berning, Torsten; Kær, Søren Knudsen

    2012-01-01

    generate a local maximum, if a wrong equilibrium water content relation is used. Finally, in order to study the obtained diffusivity model a parameter variation is carried out using a one-dimensional steady-state model. The effect of diffusivity model, surface roughness and water content driving force...

  14. On the Diffusion Coefficient of Water in Polymer Electrolyte Membranes

    DEFF Research Database (Denmark)

    Olesen, Anders Christian; Berning, Torsten; Kær, Søren Knudsen

    2012-01-01

    The Fickian diffusivity of water in Nafion has been shown to exhibit a local maximum. In the present research effort it is shown that this spike vanishes if the equilibrium water content and chemical diffusivity are modeled carefully. Further, it is shown that permeation experiments falsely can g...

  15. 8.4.Electrolytes,water,acidbase imbalance

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930240 The mechanism of water and sodiumretention during positive end-expiratory pres-sure (PEEP) ventilation.MA Yingmin (马迎民),LIU Youning (刘又宁).General Hosp,Beijing,100853.Natl Med J China 1993;73(2):92—95.To investigate the mechanism of water andsodium retention during PEEP ventilation,tendogs were studied at 0,1.33Kpa,2.67Kpa

  16. Water balance simulations of a polymer-electrolyte membrane fuel cell using a two-fluid model

    DEFF Research Database (Denmark)

    Berning, Torsten; Odgaard, M.; Kær, Søren Knudsen

    2011-01-01

    A previously published computational multi-phase model of a polymer-electrolyte membrane fuel cell cathode has been extended in order to account for the anode side and the electrolyte membrane. The model has been applied to study the water balance of a fuel cell during operation under various hum...

  17. Water equilibria and management using a two-volume model of a polymer electrolyte fuel cell

    Science.gov (United States)

    Karnik, Amey Y.; Stefanopoulou, Anna G.; Sun, Jing

    In this paper, we introduce a modified interpretation of the water activity presented in Springer et al. [T.E. Springer, T.A. Zawodzinski, S. Gottesfeld, Polymer electrolyte fuel cell model, J. Electrochem. Soc. 138 (8) (1991) 2334-2342]. The modification directly affects the membrane water transport between the anode and the cathode (two electrodes) of the polymer electrolyte membrane (PEM) fuel cell in the presence of liquid water inside the stack. The modification permits calibration of a zero-dimensional isothermal model to predict the flooding and drying conditions in the two electrodes observed at various current levels [D. Spernjak, S. Advani, A.K. Prasad, Experimental investigation of liquid water formation and transport in a transparent single-serpentine PEM fuel cell, in: Proceedings of the Fourth International Conference on Fuel Cell Science, Engineering and Technology (FUELCELL2006-97271), June 2006]. Using this model the equilibria of the lumped water mass in the two electrodes are analyzed at various flow conditions of the stack to determine stable and unstable (liquid water growth) operating conditions. Two case studies of water management through modification of cathode inlet humidification and anode water removal are then evaluated using this model. The desired anode water removal and the desired cathode inlet humidification are specified based upon (i) the water balance requirements, (ii) the desired conditions in the electrodes, and (iii) the maximum membrane transport at those conditions.

  18. Modeling Water Management in Polymer-Electrolyte Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Department of Chemical Engineering, University of California, Berkeley; Weber, Adam; Weber, Adam Z.; Balliet, Ryan; Gunterman, Haluna P.; Newman, John

    2007-09-07

    Fuel cells may become the energy-delivery devices of the 21st century with realization of a carbon-neutral energy economy. Although there are many types of fuel cells, polymerelectrolyte fuel cells (PEFCs) are receiving the most attention for automotive and small stationary applications. In a PEFC, hydrogen and oxygen are combined electrochemically to produce water, electricity, and waste heat. During the operation of a PEFC, many interrelated and complex phenomena occur. These processes include mass and heat transfer, electrochemical reactions, and ionic and electronic transport. Most of these processes occur in the through-plane direction in what we term the PEFC sandwich as shown in Figure 1. This sandwich comprises multiple layers including diffusion media that can be composite structures containing a macroporous gas-diffusion layer (GDL) and microporous layer (MPL), catalyst layers (CLs), flow fields or bipolar plates, and a membrane. During operation fuel is fed into the anode flow field, moves through the diffusion medium, and reacts electrochemically at the anode CL to form hydrogen ions and electrons. The oxidant, usually oxygen in air, is fed into the cathode flow field, moves through the diffusion medium, and is electrochemically reduced at the cathode CL by combination with the generated protons and electrons. The water, either liquid or vapor, produced by the reduction of oxygen at the cathode exits the PEFC through either the cathode or anode flow field. The electrons generated at the anode pass through an external circuit and may be used to perform work before they are consumed at the cathode. The performance of a PEFC is most often reported in the form of a polarization curve, as shown in Figure 2. Roughly speaking, the polarization curve can be broken down into various regions. First, it should be noted that the equilibrium potential differs from the open-circuit voltage due mainly to hydrogen crossover through the membrane (i.e., a mixed potential

  19. Development of solid electrolytes for water electrolysis at intermediate temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Linkous, C.A.; Kopitzke, R.W. [Florida Solar Energy Center, Cape Canaveral, FL (United States)

    1995-09-01

    If an electrolyzer could operate at higher temperatures, several benefits would accrue. The first is that the thermodynamic electrical energy requirement to drive the reaction would be reduced. Supplying the total enthalpy of reaction at any temperature involves a combination of electrical and thermal energy inputs. Because of the positive entropy associated with water decomposition, the thermal contribution increases as temperature rises, allowing the free energy requirement to decrease. Thus the open circuit voltage, V{sub oc}, for water splitting drops as temperature rises. At room temperature, V{sub oc} for water decomposition is 1.229 V. At 400{degrees}C, voltage requirement has dropped to 1.1 V; at 1000{degrees}C, it is only 0.92 V. Since electricity is a more expensive form of energy on a btu basis, the more energy taken from the thermal surroundings the better. Moreover, this thermal energy content could be solar-derived. While the cost of solar thermal energy varies in the range of $360-900/peak kilowatt, the installed cost of photovoltaic electricity is in the range of $4,000-5,000/peak kilowatt. Thus if one is compelled to erect an array of photovoltaic panels to generate the e.m.f. necessary to split water, substituting as much area with thermal collectors as possible represents a substantial cost savings.

  20. Effect of oral water soluble vitamin K on PIVKA-II levels in newborns.

    Science.gov (United States)

    Sharma, R K; Marwaha, N; Kumar, P; Narang, A

    1995-08-01

    Intramuscular administration of vitamin K for prophylaxis against hemorrhagic disease of the newborn has the disadvantage of increased cost, pain, anxiety to parents and risk of transmission of infection. Oral route is a better alternative. Oral absorption of vitamin K has been shown to be equally good using special oral preparations. However, this preparation is not available in India. A prospective study was carried out on 51 full term, healthy breastfed newborns to evaluate if the injectable water soluble preparation of vitamin K (menadione sodium bisulphite) could be as effective. Fourteen babies received 1 mg vitamin K intramuscularly, 24 received 2 mg vitamin K orally while 13 controls did not receive vitamin K at birth. PIVKA-II levels were measured in cord blood and at 72-78 hours of age in all babies as a marker of vitamin K deficiency. The overall PIVKA-II prevalence in cord blood was 64.7%. At 72-78 hours, PIVKA-II was present in 50% of babies in IM group, 58.3% of babies in oral group and in 76.9% of babies in 'no vitamin K' group (p > 0.05). The PIVKA-II levels decreased or did not change at 72-78 hours in 91.6% of babies in oral group versus 92.8% of babies in IM group (p > 0.05). On the other hand, PIVKA-II levels increased in 30.7% of babies who did not receive vitamin K as against in 7.8% of babies receiving vitamin K in either form (p < 0.05). Hence, vitamin K prophylaxis is required for all newborns at birth and injectable vitamin K (menadione sodium bisulphite) given orally to term healthy babies is effective in preventing vitamin K deficiency state.

  1. 深度处理维生素制药废水的研究%Study on the Advanced Treatment of Waste Water in the Pharmacy by Vitamin

    Institute of Scientific and Technical Information of China (English)

    何英丽; 刘红代

    2015-01-01

    This paper takes the integration of aerobiotic-anaerobic biological strengthening reactor as the main technology of the advanced treatment, combines with the pretreatment technology of electrolytic oxidation to improve the removal efficiency of waste water in the pharmacy by vitamin.%本文采取以好氧—厌氧生物强化一体化反应器为深度处理的主体工艺,并配合电解氧化预处理工艺,以此提高维生素制药废水的去除效率。

  2. Water balance simulations of a polymer-electrolyte membrane fuel cell using a two-fluid model

    DEFF Research Database (Denmark)

    Berning, Torsten; Odgaard, M.; Kær, Søren Knudsen

    2011-01-01

    A previously published computational multi-phase model of a polymer-electrolyte membrane fuel cell cathode has been extended in order to account for the anode side and the electrolyte membrane. The model has been applied to study the water balance of a fuel cell during operation under various...... humidification conditions. It was found that the specific surface area of the electrolyte in the catalyst layers close to the membrane is of critical importance for the overall water balance. Applying a high specific electrolyte surface area close to the membrane (a water-uptake layer) can prevent drying out...... of the anode and flooding at the cathode while the average membrane water content is only weakly affected. The results also indicate that in contrast to common presumption membrane dehydration may occur at either anode or cathode side, entirely depending on the direction of the net water transport because...

  3. Comparison of activity coefficient models for atmospheric aerosols containing mixtures of electrolytes, organics, and water

    Science.gov (United States)

    Tong, Chinghang; Clegg, Simon L.; Seinfeld, John H.

    Atmospheric aerosols generally comprise a mixture of electrolytes, organic compounds, and water. Determining the gas-particle distribution of volatile compounds, including water, requires equilibrium or mass transfer calculations, at the heart of which are models for the activity coefficients of the particle-phase components. We evaluate here the performance of four recent activity coefficient models developed for electrolyte/organic/water mixtures typical of atmospheric aerosols. Two of the models, the CSB model [Clegg, S.L., Seinfeld, J.H., Brimblecombe, P., 2001. Thermodynamic modelling of aqueous aerosols containing electrolytes and dissolved organic compounds. Journal of Aerosol Science 32, 713-738] and the aerosol diameter dependent equilibrium model (ADDEM) [Topping, D.O., McFiggans, G.B., Coe, H., 2005. A curved multi-component aerosol hygroscopicity model framework: part 2—including organic compounds. Atmospheric Chemistry and Physics 5, 1223-1242] treat ion-water and organic-water interactions but do not include ion-organic interactions; these can be referred to as "decoupled" models. The other two models, reparameterized Ming and Russell model 2005 [Raatikainen, T., Laaksonen, A., 2005. Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest. Atmospheric Chemistry and Physics 5, 2475-2495] and X-UNIFAC.3 [Erdakos, G.B., Change, E.I., Pandow, J.F., Seinfeld, J.H., 2006. Prediction of activity coefficients in liquid aerosol particles containing organic compounds, dissolved inorganic salts, and water—Part 3: Organic compounds, water, and ionic constituents by consideration of short-, mid-, and long-range effects using X-UNIFAC.3. Atmospheric Environment 40, 6437-6452], include ion-organic interactions; these are referred to as "coupled" models. We address the question—Does the inclusion of a treatment of ion-organic interactions substantially improve the performance of the coupled models over

  4. Coupled Thermal and Water Management in Polymer-Electrolyte FuelCells

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Adam Z.; Newman, John

    2006-11-01

    Thermal and water management are intricately coupled in polymer-electrolyte fuel cells. In this paper, we simulate fuel-cell performance and account for nonisothermal phenomena. The transport of water due to a temperature gradient and its associated effects on performance are described, with the increase of reactant dilution by the water-vapor partial pressure being the most dominant. In addition, simulations are undergone to find the optimum operating temperature and maximum power density as a function of external heat-transfer coefficient. The shape of the optimization curves and the magnitudes of the nonisothermal phenomena are also detailed and explained.

  5. Photophysics and electrochemistry relevant to photocatalytic water splitting involved at solid–electrolyte interfaces

    KAUST Repository

    Shinagawa, Tatsuya

    2016-08-04

    Direct photon to chemical energy conversion using semiconductor-electrocatalyst-electrolyte interfaces has been extensively investigated for more than a half century. Many studies have focused on screening materials for efficient photocatalysis. Photocatalytic efficiency has been improved during this period but is not sufficient for industrial commercialization. Detailed elucidation on the photocatalytic water splitting process leads to consecutive six reaction steps with the fundamental parameters involved: The photocatalysis is initiated involving photophysics derived from various semiconductor properties (1: photon absorption, 2: exciton separation). The generated charge carriers need to be transferred to surfaces effectively utilizing the interfaces (3: carrier diffusion, 4: carrier transport). Consequently, electrocatalysis finishes the process by producing products on the surface (5: catalytic efficiency, 6: mass transfer of reactants and products). Successful photocatalytic water splitting requires the enhancement of efficiency at each stage. Most critically, a fundamental understanding of the interfacial phenomena is highly desired for establishing "photocatalysis by design" concepts, where the kinetic bottleneck within a process is identified by further improving the specific properties of photocatalytic materials as opposed to blind material screening. Theoretical modeling using the identified quantitative parameters can effectively predict the theoretically attainable photon-conversion yields. This article provides an overview of the state-of-the-art theoretical understanding of interfacial problems mainly developed in our laboratory. Photocatalytic water splitting (especially hydrogen evolution on metal surfaces) was selected as a topic, and the photophysical and electrochemical processes that occur at semiconductor-metal, semiconductor-electrolyte and metal-electrolyte interfaces are discussed.

  6. Effect of water on solid electrolyte interphase formation in Li-ion batteries

    Science.gov (United States)

    Saito, M.; Fujita, M.; Aoki, Y.; Yoshikawa, M.; Yasuda, K.; Ishigami, R.; Nakata, Y.

    2016-03-01

    Time-of-flight-elastic recoil detection analysis (TOF-ERDA) with 20 MeV Cu ions has been applied to measure the depth profiles of solid electrolyte interphase (SEI) layers on the negative electrode of lithium ion batteries (LIB). In order to obtain quantitative depth profiles, the detector efficiency was first assessed, and the test highlighted a strong mass and energy dependence of the recoiled particles, especially H and He. Subsequently, we prepared LIB cells with different water contents in the electrolyte, and subjected them to different charge-discharge cycle tests. TOF-ERDA, X-ray photoelectron spectrometry (XPS), gas chromatography (GC), ion chromatography (IC), and 1H nuclear magnetic resonance (1H NMR) were applied to characterize the SEI region of the negative electrode. The results showed that the SEI layer is formed after 300 cycle tests, and a 500 ppm water concentration in the electrolyte does not appear to cause significant differences in the elemental and organic content of the SEI.

  7. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... vitamins that the body absolutely needs: vitamins A, C, D, E, K, and the B vitamins (thiamine, ... excessive amounts of water-soluble vitamins, like vitamins C and B, are not used by the body ...

  8. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... vitamins that the body absolutely needs: vitamins A, C, D, E, K, and the B vitamins (thiamine, ... excessive amounts of water-soluble vitamins, like vitamins C and B, are not used by the body ...

  9. The measurement of tritium in water samples with electrolytic enrichment using liquid scintillation counter

    Directory of Open Access Journals (Sweden)

    Janković Marija M.

    2012-01-01

    Full Text Available Tritium (3H present in the environment decreased in the last decades and nowadays it has low activity concentrations. Measurement of low-level tritium activities in natural waters, e. g. in precipitation, groundwater, and river water requires special techniques for water pretreatment and detection of low-level radioactivity. In order to increase the tritium concentration to an easily measurable level, electrolytic enrichment must be applied. This paper presents the enrichment method performed by electrolysis in a battery of 18 cells, giving an enrichment factor of 5.84 (calculated from 59 electrolyses. The calculated mean values of the separation factor and enrichment parameter were 4.10 and 0.84, respectively. Results for tritium activity in precipitation and surface water collected in Belgrade during 2008 and 2009 are presented. The Radiation and Environmental Protection Department of the Vinča Institute of Nuclear Sciences, participated in the IAEA TRIC2008 international intercomparison exercise. The participation in the intercomparisons for any laboratory doing low-level 3H measurements in the waters is very important and useful. It is considered the best way to check the entire procedure and methods of the measurements and the reliability of the standard used. The analysis of the reported 3H activity results showed that all results for five intercomparison samples, for which electrolytic enrichment were applied prior to the 3H measurement, are acceptable.

  10. Water and electrolyte homeostasis and kidney function of desert-dwelling marsupial wallabies in Western Australia.

    Science.gov (United States)

    Bradshaw, S D; Morris, K D; Bradshaw, F J

    2001-02-01

    Prolonged drought, necessitating conservation of water, is one of the major environmental challenges faced by many Australian marsupials. Radioactive isotopes of water and sodium were used to assess the ability of two species of marsupial wallabies to maintain water and electrolyte balance during periods of extreme water deprivation in the arid Pilbara region of Western Australia. The spectacled hare-wallaby, Lagorchestes conspicillatus, has the lowest mass-specific rate of water turnover at 27.5 ml.kg(-0.82).day(-1) yet reported for any mammal and was two to three orders of magnitude lower than that of the Rothschild's rock-wallaby, Petrogale rothschildi. Studies of renal function show that the hare-wallaby conserves water by producing a highly concentrated urine under the influence of lysine vasopressin (LVP), the anti-diuretic hormone (ADH) in macropodid marsupials. In contrast, rock-wallabies show unusual renal responses to water deprivation, with no change in LVP levels and a limited response to water deprivation involving a reduction in renal plasma flow and glomerular filtration rate, with no significant change in tubular function. Both species are able to maintain water and electrolyte homeostasis during periods of drought, highlighting the efficacy of their differing adaptive solutions to the problem of water scarcity, although the hare-wallaby is superior to the rock-wallaby in this respect. Rock-wallabies appear to rely primarily on behavioural rather than physiological responses for their survival in the Pilbara and appear to be more vulnerable to extinction in the event of significant habitat modification. The secure nature of their rock habitat, however, means that they have suffered less than hare-wallabies in the recent past.

  11. Water-soluble vitamin deficiencies in complicated peptic ulcer patients soon after ulcer onset in Japan.

    Science.gov (United States)

    Miyake, Kazumasa; Akimoto, Teppei; Kusakabe, Makoto; Sato, Wataru; Yamada, Akiyoshi; Yamawaki, Hiroshi; Kodaka, Yasuhiro; Shinpuku, Mayumi; Nagoya, Hiroyuki; Shindo, Tomotaka; Ueki, Nobue; Kusunoki, Masafumi; Kawagoe, Tetsuro; Futagami, Seiji; Tsukui, Taku; Sakamoto, Choitsu

    2013-01-01

    We investigated over time whether contemporary Japanese patients with complicated peptic ulcers have any water-soluble vitamin deficiencies soon after the onset of the complicated peptic ulcers. In this prospective cohort study, fasting serum levels of water-soluble vitamins (vitamins B1, B2, B6, B12, C, and folic acid) and homocysteine were measured at 3 time points (at admission, hospital discharge, and 3 mo after hospital discharge). Among the 20 patients who were enrolled in the study, 10 consecutive patients who completed measurements at all 3 time points were analyzed. The proportion of patients in whom any of the serum water-soluble vitamins that we examined were deficient was as high as 80% at admission, and remained at 70% at discharge. The proportion of patients with vitamin B6 deficiency was significantly higher at admission and discharge (50% and 60%, respectively, ppeptic ulcers may have a deficiency of one or more water-soluble vitamins in the early phase of the disease after the onset of ulcer complications, even in a contemporary Japanese population.

  12. Water transport in the gas diffusion layer of a polymer electrolyte fuel cell : Dynamic Pore-Network Modeling

    NARCIS (Netherlands)

    Qin, C.

    2015-01-01

    The pore-scale modeling is a powerful tool for increasing our understanding of water transport in the fibrous gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEFC). In this work, a new dynamic pore-network model for air-water flow in the GDL is developed. It incorporates water vapor tr

  13. Electrolyte engineering toward efficient water splitting at mild pH

    KAUST Repository

    Shinagawa, Tatsuya

    2017-08-28

    The development of processes for the conversion of H2O/CO2 driven by electricity generated in renewable manners is essential to achieve sustainable energy and chemical cycles, in which the electrocatalytic oxygen evolution reaction (OER) is one of the bottlenecks. In this contribution, the influences of the electrolyte molarity and identity on OER at alkaline to neutral pH were investigated at an appreciable current density of ~10 mA cm-2, revealing (1) the clear boundary of reactant switching between H2O/OH- due to the diffusion limitation of OH- and (2) the substantial contribution of the mass transport of the buffered species in buffered mild pH conditions. These findings propose a strategy of electrolyte engineering: tuning the electrolyte properties to maximize the mass-transport flux. The concept was successfully demonstrated for OER as well as overall water electrolysis in buffered mild pH conditions, shedding light on the development of practical solar fuel production systems.

  14. Possibilities of improving the efficiency of power generation with regard to electrolytic water splitting

    Science.gov (United States)

    Knoche, K. F.; Hasberg, W.; Roth, M.

    The efficiency of power generation has a considerable influence on the upper limit of the total efficiency of electrolytic water splitting. This paper deals with the energetic potential of power generation processes and therefore with the water electrolysis processes. In the investigations reported here, it was assumed that the heat source is always the same (high-temperature nuclear reactor). For comparing thermochemical or hybrid water splitting cycles and water electrolysis, the upper limit of process temperatures must be comparable, too. Therefore, high-temperature processes for power generation have been investigated. A detailed energy and exergy balance is presented for the following cycles: (1) steam turbine cycles; (2) helium gas turbine cycles; (3) combined gas/steam turbine cycles. For these different processes an exergy analysis was performed in order to localize the process units, which make a considerable contribution to the decrease in total efficiency.

  15. Water soluble graphene as electrolyte additive in magnesium-air battery system

    Science.gov (United States)

    Saminathan, K.; Mayilvel Dinesh, M.; Selvam, M.; Srither, S. R.; Rajendran, V.; Kaler, Karan V. I. S.

    2015-02-01

    Magnesium-air (Mg-air) batteries are an important energy source used to power electronic equipment and automobiles. Metal-air batteries give more energy density due to surplus air involved in reduction reaction at air cathode. In this study, the scope of improvements in the efficiency of Metal-air batteries is investigated through addition of water soluble graphene (WSG) as inhibitor in NaCl electrolyte. The discharge performance, corrosion behaviour and electrochemical impedance are studied for (i) the conventional Mg-air battery using 3.5% NaCl and (ii) Mg-air battery with WSG-based 3.5% NaCl electrolyte. X-ray diffraction analysis for WSG is carried out and it shows the crystalline nature of WSG by an intense sharp peak at 26.3°. Scanning electron microscope study is also performed and shows the flake-like structure of WSG denoted by thin layers of carbon. The immersion of WSG in 3.5% NaCl electrolyte increased the current density from 13.24 to 19.33 mA cm-2. Meanwhile, the WSG-based Mg-air battery was found to hold specific discharge capacity of 1030.71 mAh g-1, which was higher than that obtained in 3.5% NaCl electrolyte (i.e., 822.85 mAh g-1). The WSG-based Mg-air battery shows good self-discharge capacity and higher electrochemical activity during discharge.

  16. High-Efficiency Glass and Printable Flexible Dye-Sensitized Solar Cells with Water-Based Electrolytes

    Directory of Open Access Journals (Sweden)

    Omar Moudam

    2014-01-01

    Full Text Available The performance of a flexible and glass dye-sensitized solar cell (DSSC with water-based electrolyte solutions is described. High concentrations of alkylamidazoliums were used to overcome the deleterious effect of water and, based on this variable, pure water-based electrolyte DSSCs were tested displaying the highest recorded efficiency so far of 3.45% and 6% for flexible and glass cells, respectively, under a simulated air mass 1.5 solar spectrum illumination at 100 mWcm−2. An improvement in the Jsc with high water content and the positive impact of GuSCN on the enhancement of the performance of pure water-based electrolytes were also observed.

  17. Effects of Beer, Non-Alcoholic Beer and Water Consumption before Exercise on Fluid and Electrolyte Homeostasis in Athletes

    OpenAIRE

    Mauricio Castro-Sepulveda; Neil Johannsen; Sebastián Astudillo; Carlos Jorquera; Cristian Álvarez; Hermann Zbinden-Foncea; Rodrigo Ramírez-Campillo

    2016-01-01

    Fluid and electrolyte status have a significant impact on physical performance and health. Pre-exercise recommendations cite the possibility of consuming beverages with high amounts of sodium. In this sense, non-alcoholic beer can be considered an effective pre-exercise hydration beverage. This double-blind, randomized study aimed to compare the effect of beer, non-alcoholic beer and water consumption before exercise on fluid and electrolyte homeostasis. Seven male soccer players performed 45...

  18. Removal of charged micropollutants from water by ion-exchange polymers -- effects of competing electrolytes.

    Science.gov (United States)

    Bäuerlein, Patrick S; Ter Laak, Thomas L; Hofman-Caris, Roberta C H M; de Voogt, Pim; Droge, Steven T J

    2012-10-15

    A wide variety of environmental compounds of concern, e.g. pharmaceuticals or illicit drugs, are acids or bases that may predominantly be present as charged species in drinking water sources. These charged micropollutants may prove difficult to remove by currently used water treatment steps (e.g. UV/H(2)O(2), activated carbon (AC) or membranes). We studied the sorption affinity of some ionic organic compounds to both AC and different charged polymeric materials. Ion-exchange polymers may be effective as additional extraction phases in water treatment, because sorption of all charged compounds to oppositely charged polymers was stronger than to AC, especially for the double-charged cation metformin. Tested below 1% of the polymer ion-exchange capacity, the sorption affinity of charged micropollutants is nonlinear and depends on the composition of the aqueous medium. Whereas oppositely charged electrolytes do not impact sorption of organic ions, equally charged electrolytes do influence sorption indicating ion-exchange (IE) to be the main sorption mechanism. For the tested polymers, a tenfold increased salt concentration lowered the IE-sorption affinity by a factor two. Different electrolytes affect IE with organic ions in a similar way as inorganic ions on IE-resins, and no clear differences in this trend were observed between the sulphonated and the carboxylated cation-exchanger. Sorption of organic cations is five fold less in Ca(2+) solutions compared to similar concentrations of Na(+), while that of anionic compounds is three fold weaker in SO(4)(2-) solutions compared to equal concentrations of Cl(-).

  19. Dialkylimidazolium ionic liquids as electrolytes for hydrogen production from water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    De Souza, Roberto F.; Padilha, Janine C.; Goncalves, Reinaldo S. [Department of Physical Chemistry, Institute of Chemistry, UFRGS, Av. Bento Goncalves, 9500, Porto Alegre, RS 91501-970 (Brazil); Rault-Berthelot, Joeelle [Laboratoire d ' Electrochimie Moleculaire et Macromoleculaire, UMR CNRS no. 6510 - Universite de Rennes 1, Institut de Chimie de Rennes, Campus Beaulieu, 35042 Rennes (France)

    2006-02-01

    Imidazolium ionic liquids (ILs) such as BMI.BF{sub 4} and BMI.PF{sub 6} were studied by cyclic voltammetry (CV). BMI.BF{sub 4} was used as an electrolyte for hydrogen production through water electrolysis. The system using this ionic liquid in a conventional electrochemical cell with platinum electrodes at room temperature and atmospheric pressure gives current densities (j) higher than 20mAcm{sup -2} and efficiencies of more than 94.5%. The catalytic activity of the electrode surface was not affected during the electrolyses mainly due to the chemical stability of the IL. (author)

  20. A Hydrogen-Evolving Hybrid-Electrolyte Battery with Electrochemical/Photoelectrochemical Charging from Water Oxidation.

    Science.gov (United States)

    Jin, Zhaoyu; Li, Panpan; Xiao, Dan

    2017-02-08

    Decoupled hydrogen and oxygen production were successfully embedded into an aqueous dual-electrolyte (acid-base) battery for simultaneous energy storage and conversion. A three-electrode configuration was adopted, involving an electrocatalytic hydrogen-evolving electrode as cathode, an alkaline battery-type or capacitor-type anode as shuttle, and a charging-assisting electrode for electro-/photoelectrochemically catalyzing water oxidation. The conceptual battery not only synergistically outputs electricity and chemical fuels with tremendous specific energy and power densities, but also supports various approaches to be charged by pure or solar-assisted electricity.

  1. Solid polymer electrolyte water electrolysis system development. [to generate oxygen for manned space station applications

    Science.gov (United States)

    1975-01-01

    Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary instrumentation and controls was fabricated and tested. A six man rated, high pressure, high temperature, advanced preprototype WES was developed. This configuration included the design and development of an advanced water electrolysis module, capable of operation at 400 psig and 200 F, and a dynamic phase separator/pump in place of a passive phase separator design. Evaluation of this system demonstrated the goal of safe, unattended automated operation at high pressure and high temperature with an accumulated gas generation time of over 1000 hours.

  2. Concentrations of Water-Soluble Vitamins in Blood and Urinary Excretion in Patients with Diabetes Mellitus

    Science.gov (United States)

    Iwakawa, Hiromi; Nakamura, Yasuyuki; Fukui, Tomiho; Fukuwatari, Tsutomu; Ugi, Satoshi; Maegawa, Hiroshi; Doi, Yukio; Shibata, Katsumi

    2016-01-01

    We examined the concentrations of water-soluble vitamins in blood and urinary excretion of 22 patients with type 2 diabetes mellitus (type 2DM) and 20 healthy control participants. Macronutrient and vitamin intakes of type 2DM subjects were measured using a weighed food record method. Control participants consumed a semipurified diet for eight days. Multiple linear regression models were used to determine whether significant differences existed in vitamin concentrations in blood independent of age, sex, and other confounding factors. Concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors. Renal clearances of vitamins B6, C, niacin, and folate were significantly higher in type 2DM subjects than in controls. In conclusion, concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors; based on the evidence of increased urinary clearance of these vitamins, the lower levels were likely due to impaired reabsorption processes. PMID:27812289

  3. A review of water management in polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ji, M.; Wei, Z. [State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044 (China)

    2009-07-01

    At present, despite the great advances in polymer electrolyte membrane fuel cell (PEMFC) technology over the past two decades through intensive research and development activities, their large-scale commercialization is still hampered by their higher materials cost and lower reliability and durability. In this review, water management is given special consideration. Water management is of vital importance to achieve maximum performance and durability from PEMFCs. On the one hand, to maintain good proton conductivity, the relative humidity of inlet gases is typically held at a large value to ensure that the membrane remains fully hydrated. On the other hand, the pores of the catalyst layer and the gas diffusion layer are frequently flooded by excessive liquid water, resulting in a higher mass transport resistance. Thus, a subtle equilibrium has to be maintained between membrane drying and liquid water flooding to prevent fuel cell degradation and guarantee a high performance level, which is the essential problem of water management. This paper presents a comprehensive review of the state-of-the-art studies of water management, including the experimental methods and modeling and simulation for the characterization of water management and the water management strategies. As one important aspect of water management, water flooding has been extensively studied during the last two decades. Herein, the causes, detection, effects on cell performance and mitigation strategies of water flooding are overviewed in detail. In the end of the paper the emphasis is given to: (i) the delicate equilibrium of membrane drying vs. water flooding in water management; (ii) determining which phenomenon is principally responsible for the deterioration of the PEMFC performance, the flooding of the porous electrode or the gas channels in the bipolar plate, and (iii) what measures should be taken to prevent water flooding from happening in PEMFCs. (author)

  4. A Review of Water Management in Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Zidong Wei

    2009-11-01

    Full Text Available At present, despite the great advances in polymer electrolyte membrane fuel cell (PEMFC technology over the past two decades through intensive research and development activities, their large-scale commercialization is still hampered by their higher materials cost and lower reliability and durability. In this review, water management is given special consideration. Water management is of vital importance to achieve maximum performance and durability from PEMFCs. On the one hand, to maintain good proton conductivity, the relative humidity of inlet gases is typically held at a large value to ensure that the membrane remains fully hydrated. On the other hand, the pores of the catalyst layer (CL and the gas diffusion layer (GDL are frequently flooded by excessive liquid water, resulting in a higher mass transport resistance. Thus, a subtle equilibrium has to be maintained between membrane drying and liquid water flooding to prevent fuel cell degradation and guarantee a high performance level, which is the essential problem of water management. This paper presents a comprehensive review of the state-of-the-art studies of water management, including the experimental methods and modeling and simulation for the characterization of water management and the water management strategies. As one important aspect of water management, water flooding has been extensively studied during the last two decades. Herein, the causes, detection, effects on cell performance and mitigation strategies of water flooding are overviewed in detail. In the end of the paper the emphasis is given to: (i the delicate equilibrium of membrane drying vs. water flooding in water management; (ii determining which phenomenon is principally responsible for the deterioration of the PEMFC performance, the flooding of the porous electrode or the gas channels in the bipolar plate, and (iii what measures should be taken to prevent water flooding from happening in PEMFCs.

  5. The stability of water- and fat-soluble vitamin in dentifrices according to pH level and storage type.

    Science.gov (United States)

    Park, Jung-Eun; Kim, Ki-Eun; Choi, Yong-Jun; Park, Yong-Duk; Kwon, Ha-Jeong

    2016-02-01

    The purpose of this study is to evaluate the vitamin stabilities in dentifrices by analyzing various vitamins according to the level and storage temperature. The stabilities of water- and fat-soluble vitamins were investigated in buffer solution at different pH values (4, 7, 8, 10 and 11) for 14 days and in dentifrices at different pH (7 and 10) for 5 months at two temperature conditions (room and refrigeration temperature) by analyzing the remaining amounts using HPLC methods. In the buffer solution, the stability of vitamins B1 , B6 and C was increased as the pH values increased. Vitamins E and K showed poor stability at pH 4, and vitamin B3 showed poor stability at pH 11. In dentifrices, the storage temperature highly influenced vitamin stability, especially vitamins C and E, but the stabilities of vitamins B1 and C according to pH values did not correspond to the buffer solution tests. Vitamin B group was relatively stable in dentifrices, but vitamin C completely disappeared after 5 months. Vitamin K showed the least initial preservation rates. Vitamins were not detected in commercial dentifrices for adults and detected amounts were less than the advertised contents in dentifrices for children.

  6. Fat-soluble and water-soluble vitamin contents of breast milk from Japanese women.

    Science.gov (United States)

    Sakurai, Takayuki; Furukawa, Miyako; Asoh, Miyuki; Kanno, Takahiro; Kojima, Tadashi; Yonekubo, Akie

    2005-08-01

    To determine the concentrations of fat-soluble and water-soluble vitamins in the maternal milk of Japanese women, we collected human milk samples from more than 4,000 mothers living throughout Japan between December 1998 and September 1999, and defined as group A the 691 samples among these that met the following conditions: breast milk of mothers who were under 40 y of age, who did not smoke habitually and/or use vitamin supplements, and whose babies showed no symptoms of atopy and had birth weights of 2.5 kg or more. We then analyzed the contents of vitamins individually. Large differences were observed among the contents of individual human milk samples. The mean contents of each component were as follows: vitamin A, 159.0 +/- 95.2 IU/100 mL; vitamin E, 0.325 +/- 0.165 alpha-TE mg/100mL; vitamin D3 (cholecalciferol), 8.0 +/- 10.7 ng/100mL; vitamin B1 (thiamin), 12.3 +/- 3.2 microg/100 mL; vitamin B2, 38.4 +/- 12.7 microg/100 mL; vitamin B6, 5.7 +/- 2.5 microg/100 mL; vitamin B12, 0.04 +/- 0.02 microg/100 mL; vitamin C, 5.1 +/- 1.9 mg/100 mL; biotin, 0.50 +/- 0.23 microg/100 mL; choline, 9.2 +/- 1.8 mg/100 mL; folic acid, 6.2 +/- 2.9 microg/100 mL; inositol, 12.6 +/- 3.6 mg/100 mL; niacin (nicotinamide), 32.9 +/- 20.4 microg/100 mL and pantothenic acid, 0.27 +/- 0.09 mg/100 mL. The concentrations of derivatives and/or related compounds of vitamin A (retinol, beta-carotene), vitamin E (alpha-, beta-, gamma-, and delta-tocopherol), and B2 (riboflavin, FMN, and FAD) were determined separately. The contents of each were found to vary greatly as the duration of lactation increased. The present results indicate that it is necessary to evaluate individual differences in human milk in order to perform valid research regarding infant formula.

  7. CFTR genotype-related body water and electrolyte balance during a marathon.

    Science.gov (United States)

    Del Coso, J; Lara, B; Salinero, J J; Areces, F; Ruiz-Vicente, D; Gallo-Salazar, C; Abián-Vicén, J; Cacabelos, R

    2016-09-01

    The aim of this investigation was to determine the influence of CFTR genotype on body water and electrolyte balance during a marathon. Fifty-one experienced runners completed a marathon race. Before and after the race, body mass and a sample of venous blood were obtained. During the race, sweat samples were collected using sweat patches, and fluid and electrolyte intake were obtained using self-reported questionnaires. Thirty-eight participants (74.5% of the total) were 7T/7T homozygotes, 11 (21.6%) were 7T/9T heterozygotes, and one participant presented the rare genotype 5T/7T. Another participant with 9T/9T presented the mutation p.L206W. Participants with 7T/7T showed higher sweat sodium concentrations (42.2 ± 21.6 mmol/L) than 7T/9T (29.0 ± 24.7 mmol/L; P = 0.04). The runner with the 5T/7T genotype (10.2 mmol/L) and the participant with the p.L206W mutation (20.5 mmol/L) exhibited low-range sweat sodium concentrations. However, post-race serum sodium concentration was similar in 7T/7T and 7T/9T (142.1 ± 1.3 and 142.4 ± 1.6 mmol/L, respectively; P = 0.27) and did not show abnormalities in participants with the 5T/7T genotype (140.0 mmol/L) and the p.L206W mutation (143.0 mmol/L). Runners with the CFTR-7T/7T genotype exhibited increased sweat sodium concentrations during a marathon. However, this phenotype was not related with increased likelihood of suffering body water and electrolyte imbalances during real competitions.

  8. Evaluation of electroosmotic drag coefficient of water in hydrated sodium perfluorosulfonate electrolyte polymer.

    Science.gov (United States)

    Yan, Liuming; Shao, Changle; Ji, Xiaobo

    2009-07-15

    The electroosmotic drag coefficient of water molecules in hydrated sodium perfluorosulfonate electrolyte polymer is evaluated on the basis of the velocity distribution functions of the sodium cations and water molecules with an electric field applied using molecular dynamics simulations. The simulation results indicate that both velocity distribution functions of water molecules and of sodium cations agree well with the classic Maxwellian velocity distribution functions when there is no electric field applied. If an electric field is applied, the distribution functions of velocity component in directions perpendicular to the applied electric field still agree with the Maxwellian velocity distribution functions but with different temperature parameters. In the direction of the applied electric field, the electric drag causes the velocity distribution function to deviate from the Maxwellian velocity distribution function; however, to obey the peak shifted Maxwellian distribution function. The peak shifting velocities coincide with the average transport velocities induced by the electric field, and could be applied to the evaluation of the electroosmotic drag coefficient of water. By evaluation of the transport velocities of water molecules in the first coordination shells of sodium cations, sulfonate anion groups, and in the bulk, it is clearly shown that the water molecules in the first coordination shell of sodium cations are the major contribution to the electroosmotic drag and momentum transfer from water molecules within the first coordination shell to the other water molecules also contributes to the electroosmotic drag.

  9. Water-soluble vitamin homeostasis in fasting northern elephant seals (Mirounga angustirostris) measured by metabolomics analysis and standard methods

    Science.gov (United States)

    Boaz, Segal M.; Champagne, Cory D.; Fowler, Melinda A.; Houser, Dorian H.; Crocker, Daniel E.

    2011-01-01

    Despite the importance of water-soluble vitamins to metabolism, there is limited knowledge of their serum availability in fasting wildlife. We evaluated changes in water-soluble vitamins in northern elephant seals, a species with an exceptional ability to withstand nutrient deprivation. We used a metabolomics approach to measure vitamins and associated metabolites under extended natural fasts for up to seven weeks in free-ranging lactating or developing seals. Water-soluble vitamins were not detected with this metabolomics platform, but could be measured with standard assays. Concentrations of measured vitamins varied independently, but all were maintained at detectable levels over extended fasts, suggesting that defense of vitamin levels is a component of fasting adaptation in the seals. Metabolomics was not ideal for generating complete vitamin profiles in this species, but gave novel insights into vitamin metabolism by detecting key related metabolites. For example, niacin level reductions in lactating females were associated with significant reductions in precursors suggesting downregulation of the niacin synthetic pathway. The ability to detect individual vitamins using metabolomics may be impacted by the large number of novel compounds detected. Modifications to the analysis platforms and compound detection algorithms used in this study may be required for improving water-soluble vitamin detection in this and other novel wildlife systems. PMID:21983145

  10. Water-soluble vitamin homeostasis in fasting northern elephant seals (Mirounga angustirostris) measured by metabolomics analysis and standard methods.

    Science.gov (United States)

    Boaz, Segal M; Champagne, Cory D; Fowler, Melinda A; Houser, Dorian H; Crocker, Daniel E

    2012-02-01

    Despite the importance of water-soluble vitamins to metabolism, there is limited knowledge of their serum availability in fasting wildlife. We evaluated changes in water-soluble vitamins in northern elephant seals, a species with an exceptional ability to withstand nutrient deprivation. We used a metabolomics approach to measure vitamins and associated metabolites under extended natural fasts for up to 7 weeks in free-ranging lactating or developing seals. Water-soluble vitamins were not detected with this metabolomics platform, but could be measured with standard assays. Concentrations of measured vitamins varied independently, but all were maintained at detectable levels over extended fasts, suggesting that defense of vitamin levels is a component of fasting adaptation in the seals. Metabolomics was not ideal for generating complete vitamin profiles in this species, but gave novel insights into vitamin metabolism by detecting key related metabolites. For example, niacin level reductions in lactating females were associated with significant reductions in precursors suggesting downregulation of the niacin synthetic pathway. The ability to detect individual vitamins using metabolomics may be impacted by the large number of novel compounds detected. Modifications to the analysis platforms and compound detection algorithms used in this study may be required for improving water-soluble vitamin detection in this and other novel wildlife systems.

  11. Adhesion between Silica Particle and Mica Surfaces in Water and Electrolyte Solutions.

    Science.gov (United States)

    Vakarelski; Ishimura; Higashitani

    2000-07-01

    An atomic force microscope (AFM) is used to study the adhesion between a silica sphere and a mica plate in pure water and solutions of monovalent cations (LiCl, NaCl, KCl, and CsCl). It is found that the adhesive force depends not only on the electrolyte concentration but also on the hydration enthalpy of cations and the contact time of the particle on the surface. Possible mechanisms by which the observed phenomena can be explained consistently are discussed extensively. It is suggested that the adhesive force is closely related to the structure of the layer of cations and water molecules adsorbed on the surfaces: the strong adhesive force is obtained when highly hydrated cations (Li(+), Na(+)) are adsorbed to form a thick but weakly adsorbed layer, while the weak adhesive force is observed when poorly hydrated cations (Cs(+), K(+)) are adsorbed to form a thin but strongly adsorbed layer. Copyright 2000 Academic Press.

  12. Electrolytes at Solid-Water Interfaces: Theoretical Studies for Practical Applications

    Energy Technology Data Exchange (ETDEWEB)

    Striolo, Alberto

    2013-09-23

    The goal of this research program was to determine how a solid substrate affects structure and dynamics of aqueous electrolyte solutions. From fundamental observations, we seek to improve practical applications. Of particular interest at the project inset were carbon nanotube separation, electric double layer capacitors, and water desalination. As time progresses, we became interested in sub-surface water transport and fate, and in hydraulic fracturing. We employed an arsenal of techniques based on atomistic molecular dynamics simulations. We validated our methods using experimental data, to propose practical improvements. Some experiments were conducted in house. We established valuable collaborations with experienced scientists at National Laboratories to provide information not attainable with our in-house resources.

  13. Hydrogen production by water decomposition using a combined electrolytic-thermochemical cycle

    Science.gov (United States)

    Farbman, G. H.; Brecher, L. E.

    1976-01-01

    A proposed dual-purpose power plant generating nuclear power to provide energy for driving a water decomposition system is described. The entire system, dubbed Sulfur Cycle Water Decomposition System, works on sulfur compounds (sulfuric acid feedstock, sulfur oxides) in a hybrid electrolytic-thermochemical cycle; performance superior to either all-electrolysis systems or presently known all-thermochemical systems is claimed. The 3345 MW(th) graphite-moderated helium-cooled reactor (VHTR - Very High Temperature Reactor) generates both high-temperature heat and electric power for the process; the gas stream at core exit is heated to 1850 F. Reactor operation is described and reactor innards are illustrated. A cost assessment for on-stream performance in the 1990's is optimistic.

  14. The study of electrical conductivity and diffusion behavior of water-based and ferro/ferricyanide-electrolyte-based alumina nanofluids.

    Science.gov (United States)

    Liu, Chang; Lee, Hyeonseok; Chang, Ya-Huei; Feng, Shien-Ping

    2016-05-01

    Nanofluids are liquids containing suspensions of solid nanoparticles and have attracted considerable attention because they undergo substantial mass transfer and have many potential applications in energy technologies. Most studies on nanofluids have used low-ionic-strength solutions, such as water and ethanol. However, very few studies have used high-ionic-strength solutions because the aggregation and sedimentation of nanoparticles cause a stability problem. In this study, a stable water-based alumina nanofluid was prepared using stirred bead milling and exhibits a high electrical conductivity of 2420 μS/cm at 23 °C and excellent stability after five severe freezing-melting cycles. We then developed a process for mixing the water-based nanofluid with a high-ionic-strength potassium ferro/ferricyanide electrolyte and sodium dodecyl sulfate by using stirred bead milling and ultrasonication, thus forming a stable electrolyte-based nanofluid. According to the rotating disk electrode study, the electrolyte-based alumina nanofluid exhibits an unusual increase in the limiting current at high angular velocities, resulting from a combination of local percolation behavior and shear-induced diffusion. The electrolyte-based alumina nanofluid was demonstrated in a possible thermogalvanic application, since it is considered to be an alternative electrolyte for thermal energy harvesters because of the increased electrical conductivity and confined value of thermal conductivity.

  15. Hydrosoluble vitamins.

    Science.gov (United States)

    Chawla, Jasvinder; Kvarnberg, David

    2014-01-01

    The hydrosoluble vitamins are a group of organic substances that are required by humans in small amounts to prevent disorders of metabolism. Significant progress has been made in our understanding of the biochemical, physiologic and nutritional aspects of the water-soluble vitamins. Deficiency of these particular vitamins, most commonly due to inadequate nutrition, can result in disorders of the nervous system. Many of these disorders have been successfully prevented in developed countries; however, they are still common in developing countries. Of the hydrosoluble vitamins, the nervous system depends the most on vitamins B and C (ascorbic acid) for proper functioning. The B group vitamins include thiamin (vitamin B1), riboflavin (vitamin B2), niacin or niacinamide (vitamin B3), pantothenic acid (vitamin B5), pyridoxine or pyridoxal (vitamin B6) and cobalamin (vitamin B12). Clinical findings depend upon the deficiency of the underlying vitamin; generally, deficiency symptoms are seen from a combination rather than an isolated vitamin deficiency. True hereditary metabolic disorders and serious deficiency-associated diseases are rare and in general limited to particular geographic regions and high-risk groups. Their recognition is truly important as that determines the appropriate therapeutic management. The general availability of vitamins to practically everyone and several national health programs have saved many lives and prevented complications. However, there has been some apprehension for several decades about how harmless generous dosages of these vitamins are. Overt overdosages can cause vitamin toxicity affecting various body systems including the nervous system. Systemically, vitamin toxicity is associated with nonspecific symptoms, such as nausea, vomiting, diarrhea, and skin rash which are common with any acute or chronic vitamin overdose. At a national level, recommended daily allowances for vitamins become policy statements. Nutrition policy has far

  16. Liquid water transport characteristics of porous diffusion media in polymer electrolyte membrane fuel cells: A review

    Science.gov (United States)

    Liu, Xunliang; Peng, Fangyuan; Lou, Guofeng; Wen, Zhi

    2015-12-01

    Fundamental understanding of liquid water transport in gas diffusion media (GDM) is important to improve the material and structure design of polymer electrolyte membrane (PEM) fuel cells. Continuum methods of two-phase flow modeling facilitate to give more details of relevant information. The proper empirical correlations of liquid water transport properties, such as capillary characteristics, water relative permeability and effective contact angle, are crucial to two phase flow modeling and cell performance prediction. In this work, researches on these properties in the last decade are reviewed. Various efforts have been devoted to determine the water transport properties for GDMs. However, most of the experimental studies are ex-situ measurements. In-situ measurements for GDMs and extending techniques available to study the catalyst layer and the microporous layer will be further challenges. Using the Leverett-Udell correlation is not recommended for quantitative modeling. The reliable Leverett-type correlation for GDMs, with the inclusion of the cosine of effective contact angle, is desirable but hard to be established for modeling two-phase flow in GDMs. A comprehensive data set of liquid water transport properties is needed for various GDM materials under different PEM fuel cell operating conditions.

  17. Capacitance of graphene in aqueous electrolytes: The effects of dielectric saturation of water and finite size of ions

    Science.gov (United States)

    Sharma, P.; Mišković, Z. L.

    2014-09-01

    We present a theoretical model for electrolytically top-gated graphene, in which we analyze the effects of dielectric saturation of water due to possibly strong electric fields near the surface of a highly charged graphene, as well as the steric effects due to the finite size of salt ions in an aqueous electrolyte. By combining two well-established analytical models for those two effects, we show that the total capacitance of the solution-gated graphene is dominated by its quantum capacitance for gating potentials ≲1V, which is the range of primary interest for most sensor applications of graphene. On the other hand, at the potentials ≳1V the total capacitance is dominated by a universal capacitance of the electric double layer in the electrolyte, which exhibits a dramatic decrease of capacitance with increasing gating potential due to the interplay of a fully saturated dielectric constant of water and ion crowding near graphene.

  18. Osmotic diuresis-induced hypernatremia: better explained by solute-free water clearance or electrolyte-free water clearance?

    Science.gov (United States)

    Popli, Subhash; Tzamaloukas, Antonios H; Ing, Todd S

    2014-01-01

    Hypernatremia may result from inadequate water intake, excessive water loss or a combination of the two. Osmotic diuresis leads to losses of both solute and water. The relationship between solute and water losses determines the resulting changes in serum osmolality and sodium concentration. Total solute loss is routinely higher than loss of water in osmotic diuresis. Theoretically, then, decreases in serum osmolality (and serum sodium concentration) should follow. In clinical situations of osmotic diuresis, however, reduction in osmolality can take place, but not reduction in serum sodium concentration. It is of note that serum sodium concentration changes are related to urinary losses of sodium and potassium but not to the loss of total solute. In osmotic diuresis, the combined loss of sodium and potassium per liter of urine is lower than the concurrent serum sodium level. Consequently, hypernatremia can ensue. A patient who presented with osmotic diuresis and hypernatremia is described here. In this patient, we have shown that electrolyte-free water clearance is a better index of the effect of osmotic diuresis on serum sodium concentration than the classic solute-free water clearance.

  19. Electrolytes Test

    Science.gov (United States)

    ... mean? High or low electrolyte levels can be caused by several conditions and diseases. Generally, they are affected by how much is consumed in the diet and absorbed by the body, the amount of water in a person's body, and the amount eliminated ...

  20. Dynamic water management of polymer electrolyte membrane fuel cells using intermittent RH control

    Science.gov (United States)

    Hussaini, I. S.; Wang, C. Y.

    A novel method of water management of polymer electrolyte membrane (PEM) fuel cells using intermittent humidification is presented in this study. The goal is to maintain the membrane close to full humidification, while eliminating channel flooding. The entire cycle is divided into four stages: saturation and de-saturation of the gas diffusion layer followed by de-hydration and hydration of membrane. By controlling the duration of dry and humid flows, it is shown that the cell voltage can be maintained within a narrow band. The technique is applied on experimental test cells using both plain and hydrophobic materials for the gas diffusion layer and an improvement in performance as compared to steady humidification is demonstrated. Duration of dry and humid flows is determined experimentally for several operating conditions.

  1. Dynamic water management of polymer electrolyte membrane fuel cells using intermittent RH control

    KAUST Repository

    Hussaini, I.S.

    2010-06-01

    A novel method of water management of polymer electrolyte membrane (PEM) fuel cells using intermittent humidification is presented in this study. The goal is to maintain the membrane close to full humidification, while eliminating channel flooding. The entire cycle is divided into four stages: saturation and de-saturation of the gas diffusion layer followed by de-hydration and hydration of membrane. By controlling the duration of dry and humid flows, it is shown that the cell voltage can be maintained within a narrow band. The technique is applied on experimental test cells using both plain and hydrophobic materials for the gas diffusion layer and an improvement in performance as compared to steady humidification is demonstrated. Duration of dry and humid flows is determined experimentally for several operating conditions. © 2010 Elsevier B.V. All rights reserved.

  2. Development of a solid electrolyte carbon dioxide and water reduction system for oxygen recovery

    Science.gov (United States)

    Elikan, L.; Morris, J. P.; Wu, C. K.

    1972-01-01

    A 1/4-man solid electrolyte oxygen regeneration system, consisting of an electrolyzer, a carbon deposition reactor, and palladium membranes for separating hydrogen, was operated continuously in a 180-day test. Oxygen recovery from the carbon dioxide-water feed was 95%. One percent of the oxygen was lost to vacuum with the hydrogen off-gas. In a space cabin, the remaining 4% would have been recycled to the cabin and recovered. None of the electrolysis cells used in the 180-day test failed. Electrolysis power rose 20% during the test; the average power was 283.5 watts/man. Crew time was limited to 18 min/day of which 12 min/day was used for removing carbon. The success achieved in operating the system can be attributed to an extensive component development program, which is described. Stability of operation, ease of control, and flexibility in feed composition were demonstrated by the life test.

  3. Development status of solid polymer electrolyte water electrolysis for manned spacecraft life support systems

    Science.gov (United States)

    Nuttall, L. J.; Titterington, W. A.

    1974-01-01

    Details of the design and system verification test results are presented for a six-man-rated oxygen generation system. The system configuration incorporates components and instrumentation for computer-controlled operation with automatic start-up/shutdown sequencing, fault detection and isolation, and with self-contained sensors and controls for automatic safe emergency shutdown. All fluid and electrical components, sensors, and electronic controls are designed to be easily maintainable under zero-gravity conditions. On-board component spares are utilized in the system concept to sustain long-term operation (six months minimum) in a manned spacecraft application. The system is centered on a 27-cell solid polymer electrolyte water electrolysis module which, combined with the associated system components and controls, forms a total system envelope 40 in. high, 40 in. wide, and 30 in. deep.

  4. Heat and water transport in a polymer electrolyte fuel cell electrode

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Partha P [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Borup, Rod L [Los Alamos National Laboratory; Ranjan, Devesh [TEXAS A& M UNIV

    2010-01-01

    In the present scenario of a global initiative toward a sustainable energy future, the polymer electrolyte fuel cell (PEFC) has emerged as one of the most promising alternative energy conversion devices for various applications. Despite tremendous progress in recent years, a pivotal performance limitation in the PEFC comes from liquid water transport and the resulting flooding phenomena. Liquid water blocks the open pore space in the electrode and the fibrous diffusion layer leading to hindered oxygen transport. The electrode is also the only component in the entire PEFC sandwich which produces waste heat from the electrochemical reaction. The cathode electrode, being the host to several competing transport mechanisms, plays a crucial role in the overall PEFC performance limitation. In this work, an electrode model is presented in order to elucidate the coupled heat and water transport mechanisms. Two scenarios are specifically considered: (1) conventional, Nafion{reg_sign} impregnated, three-phase electrode with the hydrated polymeric membrane phase as the conveyer of protons where local electro-neutrality prevails; and (2) ultra-thin, two-phase, nano-structured electrode without the presence of ionomeric phase where charge accumulation due to electro-statics in the vicinity of the membrane-CL interface becomes important. The electrode model includes a physical description of heat and water balance along with electrochemical performance analysis in order to study the influence of electro-statics/electro-migration and phase change on the PEFC electrode performance.

  5. Metabolic acidosis and changes in water and electrolyte balance after maximal exercise.

    Science.gov (United States)

    Sejersted, O M; Medbø, J I; Hermansen, L

    1982-01-01

    The purpose of this investigation was to study lactate production and the consequent changes in acid-base status, and in water and electrolyte balance, in response to 1 min of maximal exercise in sprint- and endurance-trained subjects. So far, the results from only two subjects (one sprinter and one marathon runner) have been analysed. The rate of lactate production was higher in the sprinter than in the marathon runner, as shown by peak blood lactate concentrations of 20.8 and 13.3 mM for the two subjects, respectively. Arterial blood pH fell from 7.43 to 7.14 in the sprinter and from 7.44 to 7.23 for the marathon runner. The metabolic acidosis was partly compensated for by a lowering of arterial CO2 tension by 0.0775 kPa per 1 mM drop in base excess. In each subject large changes in water and electrolyte balance occurred. Haematocrit increased dramatically in both subjects, and the calculated decrease in plasma volume was 20% for the marathon runner and 30% for the sprinter. In each subject sodium was removed from the circulation in amounts sufficient to keep the plasma sodium concentration constant. Plasma potassium concentration was unrelated to the state of acidosis, being 2.5 mM above the resting concentration immediately after maximal exercise, and dropping by 3 mM in the subsequent 2-3 min of recovery during prevailing acidosis. The degree of lactic acidosis was large in both subjects, although more severe in the sprinter than in the endurance runner. However, buffer capacity and compensatory mechanisms were largely similar in both subjects.

  6. Changes of Chlorophyll Index (SPAD, Relative Water Content, Electrolyte Leakage and Seed Yield in Spring Safflower Genotypes under Irrigation Termination

    Directory of Open Access Journals (Sweden)

    B.E. Moosavifar

    2012-04-01

    Full Text Available In order to evaluate the effect of irrigation termination and genotype on chlorophyll index (SPAD, relative water content, electrolyte leakage and seed yield in spring safflower, an experiment was conducted, in a spilt plot arrangement based on randomized complete block design with four replications at Research Farm, Faculty of Agriculture, the University of Birjand, during 2008. Irrigation regimes (full irrigation (whole season irrigation, irrigation until grain filling, flowering and heading-bud and genotypes (Mahali Isfahan (a local variety, Isfahan28 and IL111 were arranged in main and subplots, respectively. Results showed chlorophyll content, relative water content, cell membrane stability and seed yield were influenced by irrigation termination. Provided that with terminating irrigation at an earlier stage, an increase in electrolyte leakage and reduction in relative water content and seed yield was observed in plants. There were negative relations between electrolyte leakage from plants leaf cells and seed yield. Plants which experienced irrigation termination in an earlier growth stage, suffered more damage to their cell membranes, leading to depression of their production potential. Based on the results, Mahali Isfahan and Isfahan28 can be introduced as drought resistant genotypes, because of their lower electrolyte leakage and higher relative water content. But, in general, Mahali Isfahan had the highest seed yield due to its nativeness and high adaptation to arid conditions southern of Khorasan, and therefore this genotype suggests for planting in the region.

  7. One-dimensional phenomenological model for liquid water flooding in cathode gas channel of a polymer electrolyte fuel cell

    NARCIS (Netherlands)

    Qin, C.; Hassanizadeh, S.M.; Rensink, D.; Fell, S.

    2012-01-01

    The mathematical description of liquid water flooding in the gas channel (GC) of a polymer electrolyte fuel cell (PEFC) at the macro scale has remained a challenge up to now. The mist flow assumption in the GC has been commonly used in previous numerical studies. In this work, a one-dimensional (dow

  8. Development of a solid polymer electrolyte electrolysis cell module and ancillary components for a breadboard water electrolysis system

    Science.gov (United States)

    Porter, F. J., Jr.

    1972-01-01

    Solid polymer electrolyte technology in a water electrolysis system along with ancillary components to generate oxygen and hydrogen for a manned space station application are considered. Standard commercial components are utilized wherever possible. Presented are the results of investigations, surveys, tests, conclusions and recommendations for future development efforts.

  9. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... E, K, and the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B- ... back to top Water-soluble Vitamins B-3 (niacin): flushing, redness of the skin, upset stomach. B- ...

  10. Opposing effects of low versus high concentrations of water soluble vitamins/dietary ingredients Vitamin C and niacin on colon cancer stem cells (CSCs).

    Science.gov (United States)

    Sen, Utsav; Shenoy P, Sudheer; Bose, Bipasha

    2017-07-29

    Colorectal cancer is one of the global causes of cancer deaths. Cancer stem cells (CSCs) inside the tumour niche responsible for metastasis and relapses, and hence need to be targeted for cancer therapeutics. Although dietary fibre and lifestyle changes have been recommended as measures for colorectal cancer prevention, no such recommendations are available for using water soluble vitamins as prophylaxis measure for colorectal cancers. High dose of Vitamin C has been proven to selectively kill colon cancer cells having BRAF and KRAS mutations by inducing oxidative stress. In this study, we show for the first time the opposing effects of the low and high dose of Vitamin C and vitamin B3 on colon CSCs isolated from HT-29 and HCT-15 colorectal carcinoma cell lines. At small doses, both of these vitamins exerted a cell proliferative effect only on CSCs, while there was no change in the proliferation status of non-stem cancer cells and wild-type (WT) populations. On the other hand, the death effects induced by high doses of Vitamin C and B3 were of the order of 50-60% and ∼30% on CSCs from HT-29 and HCT15, respectively. Interestingly, the control fibroblast cell line (NIH3T3) was highly refractory all the tested concentrations of Vitamin C and B3, except for the highest dose - 10,000 μg of Vitamin C that induced only 15% of cell death. Hence, these results indicate the future scope of use of therapeutic doses of Vitamin C and B3 especially in patients with advanced colorectal cancer. © 2017 International Federation for Cell Biology.

  11. Chemical constituents: water-soluble vitamins, free amino acids and sugar profile from Ganoderma adspersum.

    Science.gov (United States)

    Kıvrak, İbrahim

    2015-01-01

    Ganoderma adspersum presents a rigid fruiting body owing to chitin content and having a small quantity of water or moisture. The utility of bioactive constituent of the mushroom can only be available by extraction for human usage. In this study, carbohydrate, water-soluble vitamin compositions and amino acid contents were determined in G. adspersum mushroom. The composition in individual sugars was determined by HPLC-RID, mannitol (13.04 g/100 g) and trehalose (10.27 g/100 g) being the most abundant sugars. The examination of water-soluble vitamins and free amino acid composition was determined by UPLC-ESI-MS/MS. Essential amino acid constituted 67.79% of total amino acid, which is well worth the attention with regard to researchers and consumers. In addition, G. adspersum, which is also significantly rich in B group vitamins and vitamin C, can provide a wide range of notable applications in the pharmaceutics, cosmetics, food and dietary supplement industries. G. adspersum revealed its value for pharmacy and nutrition fields.

  12. High temperature operation of a composite membrane-based solid polymer electrolyte water electrolyser

    Energy Technology Data Exchange (ETDEWEB)

    Antonucci, V.; Di Blasi, A.; Baglio, V.; Arico, A.S. [CNR-ITAE, Via Salita S. Lucia sopra Contesse 5, 98126 Messina (Italy); Ornelas, R.; Matteucci, F. [Tozzi Apparecchiature Elettriche SpA, Via Zuccherificio, 10-48010 Mezzano (RA) (Italy); Ledesma-Garcia, J.; Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Parque Tecnologico Queretaro, Sanfandila, Pedro Escobedo, C.P. 76703 Queretaro (Mexico)

    2008-10-15

    The high temperature behaviour of a solid polymer electrolyte (SPE) water electrolyser based on a composite Nafion-SiO{sub 2} membrane was investigated and compared to that of a commercial Nafion membrane. The SPE water electrolyser performance was studied from 80 to 120{sup o}C with an operating pressure varying between 1 and 3 bar abs. IrO{sub 2} and Pt were used as oxygen and hydrogen evolution catalysts, respectively. The assemblies were manufactured by using a catalyst-coated membrane (CCM) technique. The performance was significantly better for the composite Nafion-SiO{sub 2} membrane than commercial Nafion 115. Furthermore, the composite membrane allowed suitable water electrolysis at high temperature under atmospheric pressure. The current densities were 2 and 1.2 A cm{sup -2} at a terminal voltage of 1.9 V for Nafion-SiO{sub 2} and Nafion 115, respectively, at 100{sup o}C and atmospheric pressure. By increasing the temperature up to 120{sup o}C, the performance of Nafion 115 drastically decreased; whereas, the cell based on Nafion-SiO{sub 2} membrane showed a further increase of performance, especially when the pressure was increased to 3 bar abs (2.1 A cm{sup -2} at 1.9 V). (author)

  13. Factor affecting the properties of water-in-oil-in-water emulsions for encapsulation of minerals and vitamins

    Directory of Open Access Journals (Sweden)

    Nattapong Prichapan

    2014-12-01

    Full Text Available The direct fortification of minerals and vitamins into food may induce chemical degradation, change the level of bioavailability or decrease the sensory quality of food products. The strategy to solve these problems is encapsulation technology. Numerous investigations described the use of water-in-oil-in-water (W/O/W emulsions as encapsulation system. The properties and encapsulation efficiency of W/O/W emulsions are influenced by emulsion components, the emulsification processes, and environmental conditions. The recently published results of research done on the factors affecting the properties of W/O/W emulsions for encapsulation of minerals and vitamins including form and concentration of core materials, concentration of inner water phase and lipophilic emulsifier, type and concentration of oil phase, type and concentration of hydrophilic emulsifier and stabilizer and the pH of the outer water phase have been reviewed in this article.

  14. Effect of electrolytic lesion of the dorsal raphe nucleus on water intake and sodium appetite

    Directory of Open Access Journals (Sweden)

    E.L. Olivares

    2003-12-01

    Full Text Available The present study determined the effect of an electrolytic lesion of the dorsal raphe nucleus (DRN on water intake and sodium appetite. Male Wistar rats weighing 290-320 g with a lesion of the DRN (L-DRN, performed two days before experiments and confirmed by histology at the end of the experiments, presented increased sensitivity to the dehydration induced by fluid deprivation. The cumulative water intake of L-DRN rats reached 23.3 ± 1.9 ml (a 79% increase, N = 9 while sham-lesioned rats (SL-DRN did not exceed 13.0 ± 1.0 ml (N = 11, P < 0.0001 after 5 h. The L-DRN rats treated with isoproterenol (300 µg kg-1 ml-1, sc exhibited an increase in water intake that persisted throughout the experimental period (L-DRN, 15.7 ± 1.47 ml, N = 9 vs SL-DRN, 9.3 ± 1.8 ml, N = 11, P < 0.05. The L-DRN rats also showed an increased spontaneous sodium appetite during the entire period of assessment. The intake of 0.3 M NaCl after 12, 24, 36 and 72 h by the L-DRN rats was always higher than 20.2 ± 4.45 ml (N = 10, while the intake by SL-DRN was always lower than 2.45 ± 0.86 ml (N = 10, P < 0.00001. Sodium- and water-depleted L-DRN rats also exhibited an increased sodium appetite (13.9 ± 2.0 ml, N = 11 compared to SL-DRN (4.6 ± 0.64 ml, N = 11 after 120 min of observation (P < 0.02. The sodium preference of L-DRN rats in both conditions was always higher than that of SL-DRN rats. These results suggest that electrolytic lesion of the DRN overcomes a tonic inhibitory component of sodium appetite.

  15. Water transport during startup and shutdown of polymer electrolyte fuel cell stacks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Tajiri, K.; Ahluwalia, R.K. [Argonne National Laboratory, 9700 S Cass Avenue, Argonne, IL 60439 (United States)

    2010-10-01

    A dynamic three-phase transport model is developed to analyze water uptake and transport in the membrane and catalyst layers of polymer electrolyte fuel cells during startup from subfreezing temperatures and subsequent shutdown. The initial membrane water content ({lambda}, the number of water molecules per sulfonic acid site) is found to be an important parameter that determines whether a successful unassisted self-start is possible. For a given initial subfreezing temperature at startup, there is a critical {lambda} ({lambda}{sub h}), above which self-start is not possible because the product water completely engulfs the catalyst layers with ice before the stack can warm-up to 0 C. There is a second value of {lambda} ({lambda}{sub l}), below which the stack can be self-started without forming ice. Between {lambda}{sub l} and {lambda}{sub h}, the stack can be self-started, but with intermediate formation of ice that melts as the stack warms up to 0 C. Both {lambda}{sub l} and {lambda}{sub h} are functions of the initial stack temperature, cell voltage at startup, membrane thickness, catalyst loading, and stack heat capacity. If the stack is purged during the previous shutdown by flowing air in the cathode passages, then depending on the initial amount of water in the membrane and gas diffusion layers and the initial stack temperature, it may not be possible to dry the membrane to the critical {lambda} for a subsequent successful startup. There is an optimum {lambda} for robust and rapid startup and shutdown. Startup and shutdown time and energy may be unacceptable if the {lambda} is much less than the optimum. Conversely, a robust startup from subfreezing temperatures cannot be assured if the {lambda} is much higher than this optimum. (author)

  16. Water transport during startup and shutdown of polymer electrolyte fuel cell stacks.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Tajiri, K.; Ahluwalia, R.; Nuclear Engineering Division

    2010-10-01

    A dynamic three-phase transport model is developed to analyze water uptake and transport in the membrane and catalyst layers of polymer electrolyte fuel cells during startup from subfreezing temperatures and subsequent shutdown. The initial membrane water content (?, the number of water molecules per sulfonic acid site) is found to be an important parameter that determines whether a successful unassisted self-start is possible. For a given initial subfreezing temperature at startup, there is a critical ? (?h), above which self-start is not possible because the product water completely engulfs the catalyst layers with ice before the stack can warm-up to 0 C. There is a second value of ? (?l), below which the stack can be self-started without forming ice. Between ?l and ?h, the stack can be self-started, but with intermediate formation of ice that melts as the stack warms up to 0 C. Both ?l and ?h are functions of the initial stack temperature, cell voltage at startup, membrane thickness, catalyst loading, and stack heat capacity. If the stack is purged during the previous shutdown by flowing air in the cathode passages, then depending on the initial amount of water in the membrane and gas diffusion layers and the initial stack temperature, it may not be possible to dry the membrane to the critical ? for a subsequent successful startup. There is an optimum ? for robust and rapid startup and shutdown. Startup and shutdown time and energy may be unacceptable if the ? is much less than the optimum. Conversely, a robust startup from subfreezing temperatures cannot be assured if the ? is much higher than this optimum.

  17. Water transport during startup and shutdown of polymer electrolyte fuel cell stacks

    Science.gov (United States)

    Wang, X.; Tajiri, K.; Ahluwalia, R. K.

    A dynamic three-phase transport model is developed to analyze water uptake and transport in the membrane and catalyst layers of polymer electrolyte fuel cells during startup from subfreezing temperatures and subsequent shutdown. The initial membrane water content (λ, the number of water molecules per sulfonic acid site) is found to be an important parameter that determines whether a successful unassisted self-start is possible. For a given initial subfreezing temperature at startup, there is a critical λ (λ h), above which self-start is not possible because the product water completely engulfs the catalyst layers with ice before the stack can warm-up to 0 °C. There is a second value of λ (λ l), below which the stack can be self-started without forming ice. Between λ l and λ h, the stack can be self-started, but with intermediate formation of ice that melts as the stack warms up to 0 °C. Both λ l and λ h are functions of the initial stack temperature, cell voltage at startup, membrane thickness, catalyst loading, and stack heat capacity. If the stack is purged during the previous shutdown by flowing air in the cathode passages, then depending on the initial amount of water in the membrane and gas diffusion layers and the initial stack temperature, it may not be possible to dry the membrane to the critical λ for a subsequent successful startup. There is an optimum λ for robust and rapid startup and shutdown. Startup and shutdown time and energy may be unacceptable if the λ is much less than the optimum. Conversely, a robust startup from subfreezing temperatures cannot be assured if the λ is much higher than this optimum.

  18. A pilot trial comparing the availability of vitamins C, B6, and B12 from a vitamin-fortified water and food source in humans.

    Science.gov (United States)

    Kalman, Douglas S; Lou, Lidia; Schwartz, Howard I; Feldman, Samantha; Krieger, Diane R

    2009-01-01

    In a cross-over randomized pilot study, the relative absorption of vitamins C, B(6) and B(12) were tested using a commercial vitamin-water (VW) and a standardized mixed meal (MM). Twelve adults (22.9+/-3.7 years), received the VW and the MM, randomly ordered, with a minimum 7-day washout period between. Blood was drawn pre-ingestion and over a post-ingestion period of 300+ min. Test meal quantities were formulated to contain equal amounts of vitamins B(6), B(12), and C as per the water label. Analysis revealed that a scaling factor had to be used to balance the actual content differences between test products. Using the adjusted numbers for actual water vitamin concentration, there were no differences in the maximum concentration and the 5-h area under the curve for vitamins B(6), B(12) or C between the VW and the MM. VW was found to provide similar in vivo nutrition as the test MM at a caloric saving.

  19. Teratogenicity and metabolism of water-soluble forms of vitamin A in the pregnant rat

    Energy Technology Data Exchange (ETDEWEB)

    Gunning, D.B.; Barua, A.B.; Olson, J.A. (Iowa State Univ., Ames (United States))

    1990-02-26

    Retinoyl {beta}-glucuronide, unlike retinoic acid, has been shown to be non-teratogenic when administered orally, even in large doses, to pregnant rats. The degree to which water-solubility is associated with low teratogenicity is not known. Other water-soluble forms of vitamin A have now been synthesized in our laboratory and are being evaluated for teratogenicity. New water-soluble forms of vitamin A were administered orally to pregnant Sprague-Dawley rats in a single dose of 0.35 mmole/kg bw on day 8 of gestation. On day 19, the dams were sacrificed and the litters were examined. Control animals received either vehicle only or an equivalent dose of all-trans retinoic acid. Maternal and fetal tissues were taken and analyzed by HPLC for vitamin A metabolites. In another experiment, a large single oral dose of the radiolabelled water-soluble compound was administered on day 10. At either 30 minutes or 1 hour after the dose, dams were sacrificed and the embryos analyzed both for radioactivity and for specific metabolites. In contrast to retinoyl {beta}-glucuronide, retinoyl {beta}-glucose is highly teratogenic under identical conditions. Thus, water-solubility does not seem to be the determining factor in the teratogenicity of retinoic acid conjugates.

  20. Polymer electrolyte membrane water electrolysis: Restraining degradation in the presence of fluctuating power

    Science.gov (United States)

    Rakousky, Christoph; Reimer, Uwe; Wippermann, Klaus; Kuhri, Susanne; Carmo, Marcelo; Lueke, Wiebke; Stolten, Detlef

    2017-02-01

    Polymer electrolyte membrane (PEM) water electrolysis generates 'green' hydrogen when conducted with electricity from renewable - but fluctuating - sources like wind or solar photovoltaic. Unfortunately, the long-term stability of the electrolyzer performance is still not fully understood under these input power profiles. In this study, we contrast the degradation behavior of our PEM water electrolysis single cells that occurs under operation with constant and intermittent power and derive preferable operating states. For this purpose, five different current density profiles are used, of which two were constant and three dynamic. Cells operated at 1 A cm-2 show no degradation. However, degradation was observed for the remaining four profiles, all of which underwent periods of high current density (2 A cm-2). Hereby, constant operation at 2 A cm-2 led to the highest degradation rate (194 μV h-1). Degradation can be greatly reduced when the cells are operated with an intermittent profile. Current density switching has a positive effect on durability, as it causes reversible parts of degradation to recover and results in a substantially reduced degradation per mole of hydrogen produced. Two general degradation phenomena were identified, a decreased anode exchange current density and an increased contact resistance at the titanium porous transport layer (Ti-PTL).

  1. Synthesis of zinc oxide porous structures by anodization with water as an electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Shetty, Amitha; Nanda, Karuna Kar [Indian Institute of Science, Materials Research Centre, Bangalore (India)

    2012-10-15

    We report a simple, reliable and one-step method of synthesizing ZnO porous structures at room temperature by anodization of zinc (Zn) sheet with water as an electrolyte and graphite as a counter electrode. We observed that the de-ionized (DI) water used in the experiment is slightly acidic (pH=5.8), which is due to the dissolution of carbon dioxide from the atmosphere forming carbonic acid. Porous ZnO is characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and photoluminescence (PL) studies. The current-transient measurement is carried out using a Gamry Instruments Reference 3000 and the thickness of the deposited films is measured using a Dektak surface profilometer. The PL, Raman and X-ray photoelectron spectroscopy are used to confirm the presence of ZnO phase. We have demonstrated that the hybrid structures of ZnO and poly (3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) exhibit good rectifying characteristics. The evaluated barrier height and the ideality factor are 0.45 eV and 3.6, respectively. (orig.)

  2. Chapter 30: historical aspects of the major neurological vitamin deficiency disorders: the water-soluble B vitamins.

    Science.gov (United States)

    Lanska, Douglas J

    2010-01-01

    This historical review addresses major neurological disorders associated with deficiencies of water-soluble B vitamins: beriberi, Wernicke-Korsakoff syndrome, pellagra, neural tube defects, and subacute combined degeneration of the spinal cord. Beriberi: Beriberi was known for millennia in Asia, but was not described by a European until the 17th century when Brontius in the Dutch East Indies reported the progressive sensorimotor polyneuropathy. The prevalence of beriberi increased greatly in Asia with a change in the milling process for rice in the late 19th century. In the 1880s, Takaki demonstrated the benefits of dietary modification in sailors, and later instituted dietary reforms in the Japanese Navy, which largely eradicated beriberi from the Japanese Navy by 1887. In 1889 Eijkman in Java serendipitously identified dietary factors as a major contributor to "chicken polyneuritis," which he took to be an animal model for beriberi; the polyneuritis could be cured or prevented by feeding the chickens either unpolished rice or rice polishings. By 1901, Grijns, while continuing studies of beriberi in Java, suggested a dietary deficiency explanation for beriberi after systematically eliminating deficiencies of known dietary components and excluding a toxic effect. Wernicke-Korsakoff syndrome: In the late 1870s, Wernicke identified a clinicopathological condition with ophthalmoparesis, nystagmus, ataxia, and encephalopathy, associated with punctate hemorrhages symmetrically arranged in the grey matter around the third and fourth ventricles and the aqueduct of Sylvius. In the late 1880s, Korsakoff described a spectrum of cognitive disorders, including a confabulatory amnestic state following an agitated delirium, occurring in conjunction with peripheral polyneuropathy. Beginning around 1900, investigators recognized the close relationship between Korsakoff's psychosis, delirium tremens, and Wernicke's encephalopathy, but not until several decades later were Wernicke

  3. Similarities of Water-soluble Vitamin Components among Non-prescription Pharmaceutical Vitamin Products Generally Available on the Domestic Market.

    Science.gov (United States)

    Suzuki, Keiichiro; Kojina, Moeko; Aiba, Tetsuya

    2017-01-01

     Similarities among non-prescription pharmaceutical vitamin products generally available in community pharmacies were examined based on their vitamin components, and a chart was constructed to differentiate products to assist in appropriate product choice. In the analysis of the similarities, two hundred and seventy-six data entries on vitamin products were extracted from the database on the package inserts of the pharmaceutical products provided by the Pharmaceuticals and Medical Devices Agency, and they were reviewed for the amounts of vitamins they contained, in which the B vitamins, or vitamin B1, B2, B6, B12, and niacin, were considered as well as vitamins C and E. Pantothenic acid and L-Cysteine that are frequently used in combination with those vitamins are also taken into consideration. The data entries were then processed by classical multi-dimensional scaling to evaluate the inter-product similarities. As a result, it was shown that the products categorized as pharmaceutical nutrients and tonics containing vitamins (NTcV) are similar to one another, reflecting the fact that they are less characteristic regarding their vitamin components. As for the products in other categories, they were generally found to be featured for their unique content of vitamin components, and thereby, each category includes products with a wide range of variation. It was also indicated that some products categorized as vitamin B1, B2, and C products are less distinguishable from those categorized as NTcV. These findings will assist pharmacists to decide on an appropriate product for a customer following consultation.

  4. Optimization of a quasi-solid-state dye-sensitized solar cell employing a nanocrystal-polymer composite electrolyte modified with water and ethanol.

    Science.gov (United States)

    Yang, Ying; Zhou, Cong-Hua; Xu, Sheng; Zhang, Jing; Wu, Su-Juan; Hu, Hao; Chen, Bo-Lei; Tai, Qi-Dong; Sun, Zheng-Hua; Liu, Wei; Zhao, Xing-Zhong

    2009-03-11

    A quasi-solid-state dye-sensitized solar cell employing a poly(ethylene oxide)-poly(vinylidene fluoride) (PEO-PVDF)/TiO2 gel electrolyte modified by various concentrations of water and ethanol is described. It is shown that the introduction of water and ethanol prevents the crystallization of the polymer matrix, and enhances the free I(-)/I(3)(-) concentration and the networks for ion transportation in the electrolyte, thus leading to an improvement in conductivity. A high energy conversion efficiency of about 5.8% is achieved by controlling the additive concentration in the electrolyte. Optimization of the additive-modified electrolyte performance has been obtained by studying the cross-linking behavior of water and ethanol with Fourier transform infrared (FTIR), differential scanning calorimetry (DSC) and viscosity measurements, and the electrical conduction behavior of the electrolyte with impedance spectra measurements.

  5. Drinking high-energy electrolytic water decreases internal radiation exposure caused by the Fukushima Daiichi Nuclear power plant disaster

    Directory of Open Access Journals (Sweden)

    Sawajiri Masahiko

    2016-01-01

    Full Text Available The Fukushima Daiichi Nuclear Power Plant disaster on March 11, 2011, caused radiation hazards throughout Fukushima Prefecture. Cesium was absorbed by soil and plants and transferred to livestock. Removing radioactive cesium from the bodies of farm animals and humans is essential. It has recently been reported that H2 scavenges reactive oxygen species and suppresses oxidative stress-related diseases. The hypothesis is that “active hydrogen” (hydrogen water scavenges active oxygen species. We hypothesized that high-energy electrolytic hydrogen water will effectively decontaminate cesium-exposed chickens. A test group of chickens drank high-energy electrolytic hydrogen water, while the control group drank regular water. Cesium contents in the test group were significantly lower than in the controlled one, possibly because more cesium excretion occurred in the test group than the control group. Lower 137Cs concentrations were found in test-group tissues than in control-group tissues, showing that high-energy electrolytic hydrogen water increased the rate of elimination of 137Cs incorporated into chicken tissue.

  6. Mechanisms and Regulation of Intestinal Absorption of Water-soluble Vitamins: Cellular and Molecular Aspects

    DEFF Research Database (Denmark)

    Nexø, Ebba; Said, Hamid M

    2012-01-01

    The water-soluble vitamins represent a group of structurally and functionally unrelated compounds that share the common feature of being essential for normal cellular functions, growth, and development. With the exception of some endogenous production of niacin, human cells cannot synthesize...... or deficiency. An impaired absorptive function occurs in a variety of conditions including congenital defects in the digestive or absorptive processes, intestinal diseases, drug interaction, and chronic alcohol use....

  7. INFLUENCE OF THE CONCENTRATION OF ELECTROLYTES ON THE ELECTRIFICATION AND THE RATE OF DIFFUSION OF WATER THROUGH COLLODION MEMBRANES.

    Science.gov (United States)

    Loeb, J

    1919-11-20

    1. When a watery solution is separated from pure water by a collodion membrane, the initial rate of diffusion of water into the solution is influenced in an entirely different way by solutions of electrolytes and of non-electrolytes. Solutions of non-electrolytes, e.g. sugars, influence the initial rate of diffusion of water through the membrane approximately in direct proportion to their concentration, and this. influence begins to show itself under the conditions of our experiments when the concentration of the sugar solution is above M/64 or M/32. We call this effect of the concentration of the solute on the initial rate of diffusion of water into the solution the gas pressure effect. 2. Solutions of electrolytes show the gas pressure effect upon the initial rate of diffusion also, but it commences at a somewhat higher concentration than M/64; namely, at M/16 or more (according to the nature of the electrolyte). 3. Solutions of electrolytes of a lower concentration than M/16 or M/8 have a specific influence on the initial rate of diffusion of water through a collodion membrane from pure solvent into solution which is not found in the case of the solutions of non-electrolytes and which is due to the fact that the particles of water diffuse in this case through the membrane in an electrified condition, the sign of the charge depending upon the nature of the electrolyte in solution, according to two rules given in a preceding paper. 4. In these lower concentrations the curves representing the influence of the concentration of the electrolyte on the initial rate of diffusion of water into the solution rise at first steeply with an increase in the concentration, until a maximum is reached at a concentration of M/256 or above. A further increase in concentration causes a drop-in the curve and this drop increases with a further increase of concentration until that concentration of the solute is reached in which the gas pressure effect begins to prevail; i.e., above M

  8. Dissolution kinetics and mechanisms at dolomite-water interfaces: effects of electrolyte specific ionic strength.

    Science.gov (United States)

    Xu, Man; Sullivan, Katie; Vanness, Garrett; Knauss, Kevin G; Higgins, Steven R

    2013-01-02

    Elucidating dissolution kinetics and mechanisms at carbonate mineral-water interfaces is essential to many environmental and geochemical processes, including geologic CO(2) sequestration in deep aquifers. In the present work, effects of background electrolytes on dolomite (CaMg(CO(3))(2)) reactivity were investigated by measuring step dissolution rates using in situ hydrothermal atomic force microscopy (HAFM) at 90 °C. Cleaved surfaces of dolomite were exposed to sodium chloride and tetramethylammonium chloride (TMACl) aqueous solutions with ionic strengths (I) ranging from 0 to 0.77 m at pH 4 and pH 9. HAFM results demonstrated that dolomite step retreat rates increased with increasing solution ionic strength and decreasing pH. Comparison of [481] and [441] steps revealed that the anisotropy of [481] and [441] step speeds became significant as solution ionic strength increased, with NaCl exerting more pronounced effects than TMACl for the same I. To interpret the different trends observed for NaCl and TMACl, a dissolution mechanism involving orientation-dependent ion adsorption and consequent edge free energy changes is proposed.

  9. An analysis of degradation phenomena in polymer electrolyte membrane water electrolysis

    Science.gov (United States)

    Rakousky, Christoph; Reimer, Uwe; Wippermann, Klaus; Carmo, Marcelo; Lueke, Wiebke; Stolten, Detlef

    2016-09-01

    The durability of a polymer electrolyte membrane (PEM) water electrolysis single cell, assembled with regular porous transport layers (PTLs) is investigated for just over 1000 h. We observe a significant degradation rate of 194 μV h-1 and conclude that 78% of the detectable degradation can be explained by an increase in ohmic resistance, arising from the anodic Ti-PTL. Analysis of the polarization curves also indicates a decrease in the anodic exchange current density, j0, that results from the over-time contamination of the anode with Ti species. Furthermore, the average Pt-cathode particle size increases during the test, but we do not believe this phenomenon makes a significant contribution to increased cell voltages. To validate the anode Ti-PTL as a crucial source of increasing resistance, a second cell is assembled using Pt-coated Ti-PTLs. This yields a substantially reduced degradation rate of only 12 μV h-1, indicating that a non-corroding anode PTL is vital for PEM electrolyzers. It is our hope that forthcoming tailored PTLs will not only contribute to fast progress on cost-efficient stacks, but also to its long-term application of PEM electrolyzers involved in industrial processes.

  10. Nanostructured Fe(III) catalysts for water oxidation assembled with the aid of organic acid salt electrolytes

    Science.gov (United States)

    Zhao, Qiang; Li, Dandan; Gao, Guofeng; Yuan, Wen; Hao, Genyan; Li, Jinping

    2016-11-01

    We describe the preparation of three partially ordered iron-based catalyst films (Fe-OAc, Fe-Pro, Fe-But) with nanoporous structure by electrodeposition from organate electrolytes containing Fe2+. The anions of the organic acids assisted the partial ordering of the nanostructured Fe(III) catalysts for water oxidation. A model involving an electrical double layer is invoked to explain the role of the organate electrolyte system in their formation. Analytical results have revealed the main component of the iron-based films to be a β-FeOOH structure. The Fe-But catalyst catalyzed water oxidation in 0.1 m potassium carbonate solution with an average activity of 1.48 mA cm-2 and an overpotential of 433 mV.

  11. Prevention of the water flooding by micronizing the pore structure of gas diffusion layer for polymer electrolyte fuel cell

    Science.gov (United States)

    Hiramitsu, Yusuke; Sato, Hitoshi; Hori, Michio

    In polymer electrolyte fuel cells, high humidity must be established to maintain high proton conductivity in the polymer electrolyte. However, the water that is produced electrochemically at the cathode catalyst layer can condense in the cell and cause an obstruction to the diffusion of reaction gas in the gas diffusion layer and the gas channel. This leads to a sudden decrease of the cell voltage. To combat this, strict water management techniques are required, which usually focus on the gas diffusion layer. In this study, the use of specially treated carbon paper as a flood-proof gas diffusion layer under extremely high humidity conditions was investigated experimentally. The results indicated that flooding originates at the interface between the gas diffusion layer and the catalyst layer, and that such flooding could be eliminated by control of the pore size in the gas diffusion layer at this interface.

  12. Enhanced photocatalytic-electrolytic degradation of Reactive Brilliant Red X-3B in the presence of water jet cavitation.

    Science.gov (United States)

    Wang, Xiaoning; Jia, Jinping; Wang, Yalin

    2015-03-01

    Photocatalysis, electrolysis, water jet cavitation (WJC), alone and in combinations were applied to degrade an azo dye, Reactive Brilliant Red X-3B (X-3B). Experiments were conducted in a 4.0 L aqueous solution with different initial dye concentrations, TiO₂ dose, and solution pH. WJC substantially increased the photocatalytic, electrolytic and photocatalytic-electrolytic rates of the dye removal. The observed first-order rate of X-3B decolorization in the process of combined photocatalysis and electrolysis coupled with WJC was 1.6-2.9 times of that in the process of combined photocatalysis and electrolysis coupled with mechanical stirring. The rate enhancements may be attributed primarily to the reduced diffusion layer thickness on the electrodes and the deagglomeration of photocatalyst particles due to the chemical and physical effects of WJC. Under the conditions of 80 mg/L X-3B solution, 100 mg/L TiO₂ dose and solution pH 6.3, 97% and 71% of color and chemical oxygen demand (CODCr) were removed, respectively, within 90-min photocatalytic-electrolytic treatment coupled with WJC. During this process, azo groups and naphthalene, benzene and triazine structures of the dye can be destroyed. Industrial textile effluent was also investigated, and a positive synergistic effect between photocatalytic-electrolytic system and WJC was observed considering color removal. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Prediction of thermophysical and transport properties of ternary organic non-electrolyte systems including water by polynomials

    OpenAIRE

    Đorđević Bojan D.; Kijevčanin Mirjana Lj.; Radović Ivona R.; Šerbanović Slobodan P.; Tasić Aleksandar Ž.

    2013-01-01

    The description and prediction of the thermophysical and transport properties of ternary organic non-electrolyte systems including water by the polynomial equations are reviewed. Empirical equations of Radojković et al. (also known as Redlich-Kister), Kohler, Jacob-Fitzner, Colinet, Tsao-Smith, Toop, Scatchard et al. and Rastogi et al. are compared with experimental data of available papers appeared in well know international journals (Fluid Phase Equilibria, Journal of Chemical and Eng...

  14. Removal of turbidity, COD and BOD from secondarily treated sewage water by electrolytic treatment

    Science.gov (United States)

    Chopra, Ashok Kumar; Sharma, Arun Kumar

    2013-03-01

    A preliminary study was conducted for the removal of turbidity (TD), chemical oxygen demand (COD) and biochemical oxygen demand (BOD) from secondarily treated sewage (STS) water through the electrolytic batch mode experiments with DC power supply (12 V) up to 30 min and using a novel concept of electrode combinations of different metals. The different surface areas (40, 80, 120 and 160 cm2) of the electrodes as a function of cross-sectional area of the reactor and the effect of inter-electrode distances (2.5-10 cm) on the electrolysis of STS water were studied. This study revealed that the effluent can be effectively treated with the aluminum (Al) and iron (Fe) electrode combinations (Al-Fe and Fe-Al). The maximum removal of TD (81.51 %), COD (74.36 %) and BOD (70.86 %) was recorded with Al-Fe electrode system, while the removal of these parameters was found to be 71.11, 64.95 and 61.87 %, respectively, with Fe-Al electrode combination. The Al-Fe electrode combination had lower electrical energy consumption (2.29 kWh/m3) as compared to Fe-Al electrode combination (2.50 kWh/m3). The economic evaluation of electrodes showed that Al-Fe electrode combination was better than Fe-Al electrode combination. This revealed the superiority of aluminum as a sacrificial electrode over that of iron which can probably be attributed to better flocculation capabilities of aluminum than that of iron.

  15. Effects of Beer, Non-Alcoholic Beer and Water Consumption before Exercise on Fluid and Electrolyte Homeostasis in Athletes.

    Science.gov (United States)

    Castro-Sepulveda, Mauricio; Johannsen, Neil; Astudillo, Sebastián; Jorquera, Carlos; Álvarez, Cristian; Zbinden-Foncea, Hermann; Ramírez-Campillo, Rodrigo

    2016-06-07

    Fluid and electrolyte status have a significant impact on physical performance and health. Pre-exercise recommendations cite the possibility of consuming beverages with high amounts of sodium. In this sense, non-alcoholic beer can be considered an effective pre-exercise hydration beverage. This double-blind, randomized study aimed to compare the effect of beer, non-alcoholic beer and water consumption before exercise on fluid and electrolyte homeostasis. Seven male soccer players performed 45 min of treadmill running at 65% of the maximal heart rate, 45 min after ingesting 0.7 L of water (W), beer (AB) or non-alcoholic beer (NAB). Body mass, plasma Na⁺ and K⁺ concentrations and urine specific gravity (USG) were assessed before fluid consumption and after exercise. After exercise, body mass decreased (p beer before exercise could help maintain electrolyte homeostasis during exercise. Alcoholic beer intake reduced plasma Na⁺ and increased plasma K⁺ during exercise, which may negatively affect health and physical performance, and finally, the consumption of water before exercise could induce decreases of Na⁺ in plasma during exercise.

  16. On-ice sweat rate, voluntary fluid intake, and sodium balance during practice in male junior ice hockey players drinking water or a carbohydrate-electrolyte solution

    National Research Council Canada - National Science Library

    Logan, Heather M; Spriet, Lawrence L; Palmer, Matthew S

    2010-01-01

    This study evaluated the repeatability of hydration and sweat measurements taken during on-ice hockey practices with players drinking only water, and determined whether having only a carbohydrate-electrolyte solution (CES...

  17. Modeling the Liquid Water Transport in the Gas Diffusion Layer for Polymer Electrolyte Membrane Fuel Cells Using a Water Path Network

    OpenAIRE

    Dietmar Gerteisen; Robert Alink

    2013-01-01

    In order to model the liquid water transport in the porous materials used in polymer electrolyte membrane (PEM) fuel cells, the pore network models are often applied. The presented model is a novel approach to further develop these models towards a percolation model that is based on the fiber structure rather than the pore structure. The developed algorithm determines the stable liquid water paths in the gas diffusion layer (GDL) structure and the transitions from the paths to the subsequent ...

  18. Water Transport in the Micro Porous Layer and Gas Diffusion Layer of a Polymer Electrolyte Fuel Cell

    Science.gov (United States)

    Qin, C.; Hassanizadeh, S. M.

    2015-12-01

    In this work, a recently developed dynamic pore-network model is presented [1]. The model explicitly solves for both water pressure and capillary pressure. A semi-implicit scheme is used in updating water saturation in each pore body, which considerably increases the numerical stability at low capillary number values. Furthermore, a multiple-time-step algorithm is introduced to reduce the computational effort. A number of case studies of water transport in the micro porous layer (MPL) and gas diffusion layer (GDL) are conducted. We illustrate the role of MPL in reducing water flooding in the GDL. Also, the dynamic water transport through the MPL-GDL interface is explored in detail. This information is essential to the reduced continua model (RCM), which was developed for multiphase flow through thin porous layers [2, 3]. C.Z. Qin, Water transport in the gas diffusion layer of a polymer electrolyte fuel cell: dynamic pore-network modeling, J Electrochimical. Soci., 162, F1036-F1046, 2015. C.Z. Qin and S.M. Hassanizadeh, Multiphase flow through multilayers of thin porous media: general balance equations and constitutive relationships for a solid-gas-liquid three-phase system, Int. J. Heat Mass Transfer, 70, 693-708, 2014. C.Z. Qin and S.M. Hassanizadeh, A new approach to modeling water flooding in a polymer electrolyte fuel cell, Int. J. Hydrogen Energy, 40, 3348-3358, 2015.

  19. A dynamic human water and electrolyte balance model for verification and optimization of life support systems in space flight applications

    Science.gov (United States)

    Hager, P.; Czupalla, M.; Walter, U.

    2010-11-01

    In this paper we report on the development of a dynamic MATLAB SIMULINK® model for the water and electrolyte balance inside the human body. This model is part of an environmentally sensitive dynamic human model for the optimization and verification of environmental control and life support systems (ECLSS) in space flight applications. An ECLSS provides all vital supplies for supporting human life on board a spacecraft. As human space flight today focuses on medium- to long-term missions, the strategy in ECLSS is shifting to closed loop systems. For these systems the dynamic stability and function over long duration are essential. However, the only evaluation and rating methods for ECLSS up to now are either expensive trial and error breadboarding strategies or static and semi-dynamic simulations. In order to overcome this mismatch the Exploration Group at Technische Universität München (TUM) is developing a dynamic environmental simulation, the "Virtual Habitat" (V-HAB). The central element of this simulation is the dynamic and environmentally sensitive human model. The water subsystem simulation of the human model discussed in this paper is of vital importance for the efficiency of possible ECLSS optimizations, as an over- or under-scaled water subsystem would have an adverse effect on the overall mass budget. On the other hand water has a pivotal role in the human organism. Water accounts for about 60% of the total body mass and is educt and product of numerous metabolic reactions. It is a transport medium for solutes and, due to its high evaporation enthalpy, provides the most potent medium for heat load dissipation. In a system engineering approach the human water balance was worked out by simulating the human body's subsystems and their interactions. The body fluids were assumed to reside in three compartments: blood plasma, interstitial fluid and intracellular fluid. In addition, the active and passive transport of water and solutes between those

  20. In situ liquid water visualization in polymer electrolyte membrane fuel cells with high resolution synchrotron x-ray radiography

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, S.; Banerjee, R.; Lee, J.; Ge, N.; Lee, C.; Bazylak, A., E-mail: abazylak@mie.utoronto.ca [Dept. of Mechanical & Industrial Engineering, Faculty of Applied Science & Engineering, University of Toronto, Toronto, Ontario (Canada); Wysokinski, T. W.; Belev, G.; Webb, A.; Miller, D.; Zhu, N. [Canadian Light Source, Saskatoon, Saskatchewan (Canada); Tabuchi, Y.; Kotaka, T. [EV System Laboratory, Research Division 2, Nissan Motor Co., Ltd., Yokosuka, Kanagawa (Japan)

    2016-07-27

    In this work, we investigated the dominating properties of the porous materials that impact water dynamics in a polymer electrolyte membrane fuel cell (PEMFC). Visualizations of liquid water in an operating PEMFC were performed at the Canadian Light Source. A miniature fuel cell was specifically designed for X-ray imaging investigations, and an in-house image processing algorithm based on the Beer-Lambert law was developed to extract quantities of liquid water thicknesses (cm) from raw X-ray radiographs. The X-ray attenuation coefficient of water at 24 keV was measured with a calibration device to ensure accurate measurements of the liquid water thicknesses. From this experiment, the through plane distribution of the liquid water in the fuel cell was obtained.

  1. Water and solute absorption from carbohydrate-electrolyte solutions in the human proximal small intestine: a review and statistical analysis.

    Science.gov (United States)

    Shi, Xiaocai; Passe, Dennis H

    2010-10-01

    The purpose of this study is to summarize water, carbohydrate (CHO), and electrolyte absorption from carbohydrate-electrolyte (CHO-E) solutions based on all of the triple-lumen-perfusion studies in humans since the early 1960s. The current statistical analysis included 30 reports from which were obtained information on water absorption, CHO absorption, total solute absorption, CHO concentration, CHO type, osmolality, sodium concentration, and sodium absorption in the different gut segments during exercise and at rest. Mean differences were assessed using independent-samples t tests. Exploratory multiple-regression analyses were conducted to create prediction models for intestinal water absorption. The factors influencing water and solute absorption are carefully evaluated and extensively discussed. The authors suggest that in the human proximal small intestine, water absorption is related to both total solute and CHO absorption; osmolality exerts various impacts on water absorption in the different segments; the multiple types of CHO in the ingested CHO-E solutions play a critical role in stimulating CHO, sodium, total solute, and water absorption; CHO concentration is negatively related to water absorption; and exercise may result in greater water absorption than rest. A potential regression model for predicting water absorption is also proposed for future research and practical application. In conclusion, water absorption in the human small intestine is influenced by osmolality, solute absorption, and the anatomical structures of gut segments. Multiple types of CHO in a CHO-E solution facilitate water absorption by stimulating CHO and solute absorption and lowering osmolality in the intestinal lumen.

  2. Ion pair formation in water. association constants of bolaform, bisquaternary ammonium, electrolytes by chemical trapping.

    Science.gov (United States)

    Geng, Yan; Romsted, Laurence S

    2005-12-15

    The first and second association constants, K1 and K2, for ion pair formation in aqueous 0.02-3.5 M solutions of bis(trimethyl)-alpha,omega-alkanediammonium halides with variable spacer lengths, 1-n-1 2X (n = 2-4, X = Cl, Br) and bolaform salts and for tetramethylammonium halides (TMAX, X = Cl, Br), K(TMAX), were determined by the chemical trapping method. Values for K(TMAX) are small, K(TMABr) = 0.83 M(-1) and K(TMACl) = 0.29 M(-1), in agreement with literature values. For the bolaform salts, K1 depends on spacer length and counterion type, ranges from 0.4 to 17 M(-1), is 2-10 times larger than K2, is larger for Br- than Cl-, and decreases by a factor of approximately 3 for Cl- and approximately 10 for Br- as n increases from 2 to 4. K2, for the formation of bolaform dihalide pair, is essentially the same as that for ion pair formation in TMAX solutions, i.e., K2 approximately K(TMAX). Values of K1 and K(TMABr) obtained from changes in 79Br line widths are in good agreement with those obtained by chemical trapping. The results are consistent with a thermodynamic model in which the ion association depends on the balance of the ion specific hydration free energies of cations and anions and their ion specific and hydration interactions in ion pairs. Spacer length dependent ion pairing by bolaform electrolytes, which are analogues of the headgroups and counterions of gemini amphiphiles, suggests a new model for the spacer length dependent sphere-to-rod transitions of gemini micelles. Neutral, but polar, headgroup-counterion pairs have a lower demand for hydration that free headgroups and counterions, and headgroup-counterion pair formation releases interfacial water into the bulk aqueous phase, permitting tighter amphiphile packing in rodlike micelles.

  3. Zero-Gap Alkaline Water Electrolysis Using Ion-Solvating Polymer Electrolyte Membranes at Reduced KOH Concentrations

    DEFF Research Database (Denmark)

    Kraglund, Mikkel Rykær; Aili, David; Jankova Atanasova, Katja;

    2016-01-01

    Membranes based on poly(2,2'-(m-phenylene)-5,5-bibenzimidazole) (m-PBI) can dissolve large amounts of aqueous KOH to give electrolyte systems with ion conductivity in a practically useful range. The conductivity of the membrane strongly depends on the concentration of the aqueous KOH phase......, reaching about 10-1 S cm-1 or higher in 15-25 wt% KOH. Herein, m-PBI membranes are systematically characterized with respect to performance and short-term stability as electrolyte in a zero-gap alkaline water electrolyzer at different KOH concentrations. Using plain uncatalyzed nickel foam electrodes...... exclusion chromatography and spectroscopy reveal evidence of oxidative degradation of the base polymer at KOH concentrations of 15 wt% and higher....

  4. [Some aspects of water electrolysis with the use of a solid polymer electrolyte].

    Science.gov (United States)

    Zorina, N G

    2006-01-01

    Electrochemical process in cells with a solid polymer electrolyte is dependent on catalyst durability in harsh environments and catalyst sputtering technology to ensure efficient power consumption. Active polymer electrolytes will permit to reduce substantially non-productive layouts and design a cost-effective, compact and safe system generator of high-purity oxygen and hydrogen. The existing designs of combined oxide systems integrating rear-earth and earth metals with a structure of Ln3+x Me2+1-x CoO3 containing perofskites were shown to be active catalysts in cells with a solid polymer electrolyte, and the sputtering technology was proven to reduce non-productive layouts in 2 or 2.5 times.

  5. Iron prevents ascorbic acid (vitamin C) induced hydrogen peroxide accumulation in copper contaminated drinking water.

    Science.gov (United States)

    Jansson, Patric J; Lindqvist, Christer; Nordström, Tommy

    2005-11-01

    Ascorbic acid (vitamin C) induced hydrogen peroxide (H(2)O(2)) formation was measured in household drinking water and metal supplemented Milli-Q water by using the FOX assay. Here we show that ascorbic acid readily induces H(2)O(2) formation in Cu(II) supplemented Milli-Q water and poorly buffered household drinking water. In contrast to Cu(II), iron was not capable to support ascorbic acid induced H(2)O(2) formation during acidic conditions (pH: 3.5-5). In 12 out of the 48 drinking water samples incubated with 2 mM ascorbic acid, the H(2)O(2) concentration exceeded 400 microM. However, when trace amounts of Fe(III) (0.2 mg/l) was present during incubation, the ascorbic acid/Cu(II)-induced H(2)O(2) accumulation was totally blocked. Of the other common divalent or trivalent metal ions tested, that are normally present in drinking water (calcium, magnesium, zinc, cobalt, manganese or aluminum), only calcium and magnesium displayed a modest inhibitory activity on the ascorbic acid/Cu(II)-induced H(2)O(2) formation. Oxalic acid, one of the degradation products from ascorbic acid, was confirmed to actively participate in the iron induced degradation of H(2)O(2). Ascorbic acid/Cu(II)-induced H(2)O(2) formation during acidic conditions, as demonstrated here in poorly buffered drinking water, could be of importance in host defense against bacterial infections. In addition, our findings might explain the mechanism for the protective effect of iron against vitamin C induced cell toxicity.

  6. Effects of Beer, Non-Alcoholic Beer and Water Consumption before Exercise on Fluid and Electrolyte Homeostasis in Athletes

    Directory of Open Access Journals (Sweden)

    Mauricio Castro-Sepulveda

    2016-06-01

    Full Text Available Fluid and electrolyte status have a significant impact on physical performance and health. Pre-exercise recommendations cite the possibility of consuming beverages with high amounts of sodium. In this sense, non-alcoholic beer can be considered an effective pre-exercise hydration beverage. This double-blind, randomized study aimed to compare the effect of beer, non-alcoholic beer and water consumption before exercise on fluid and electrolyte homeostasis. Seven male soccer players performed 45 min of treadmill running at 65% of the maximal heart rate, 45 min after ingesting 0.7 L of water (W, beer (AB or non-alcoholic beer (NAB. Body mass, plasma Na+ and K+ concentrations and urine specific gravity (USG were assessed before fluid consumption and after exercise. After exercise, body mass decreased (p < 0.05 in W (−1.1%, AB (−1.0% and NAB (−1.0%. In the last minutes of exercise, plasma Na+ was reduced (p < 0.05 in W (−3.9% and AB (−3.7%, plasma K+ was increased (p < 0.05 in AB (8.5%, and USG was reduced in W (−0.9% and NAB (−1.0%. Collectively, these results suggest that non-alcoholic beer before exercise could help maintain electrolyte homeostasis during exercise. Alcoholic beer intake reduced plasma Na+ and increased plasma K+ during exercise, which may negatively affect health and physical performance, and finally, the consumption of water before exercise could induce decreases of Na+ in plasma during exercise.

  7. Molecular Dynamics Simulation of Diffusion of Vitamin C in Water Solution%Molecular Dynamics Simulation of Diffusion of Vitamin C in Water Solution

    Institute of Scientific and Technical Information of China (English)

    曾建平; 王爱民; 贡雪东; 陈景文; 陈松; 薛锋

    2012-01-01

    Under different temperatures and concentrations, the diffusion of Vitamin C (VC) in water solution was exam- ined by molecular dynamics simulation. The diffusion coefficients were calculated based on the Einstein equation. The influences of temperature, concentration, and simulation time on the diffusion coefficient were discussed. The results showed that at higher temperature and lower concentration the normal diffusions appear relatively late, but the linear range of mean square displacement curves continues longer than that at lower temperature and higher concentration. At the same temperature, the normal diffusion time increases and the diffusion coefficient decreases as the simulation concentration increases. These simulation results are in good agreement with experiments. Analyses of the pair correlation functions of the simulation systems showed that hydrogen bonds are mainly formed be- tween the hydrogen atoms of VC molecules and oxygen atoms of H20 molecules, rather than between the O atoms of VC molecules and H atoms of H20 molecules. The diffusion coefficient is higher as the interaction between water molecules and VC molecules is stronger when VC concentration is lower. The water in the model systems affects the diffusion of VC molecules by the short-range repulsion of O(H20)-O(H20) pairs and the non-bond interaction of H(H20)-H(H20) pairs. The short-range repulsion of O(H20)-O(H20) pairs is greater when VC concentration is higher, the diffusion of VC is weaker. The greater the non-bond interaction of H(H20)-H(H20) pairs is, the higher the VC diffusion is. It is expected that this study can provide a theoretical direction for the experiments on the mass transfer of VC in water solution.

  8. Analysis of Water Soluble Vitamins (Thiamine, Nicotinamide and Pyridoxine in Fortified Infant Food Products by Hplc

    Directory of Open Access Journals (Sweden)

    Narjis Naz

    2016-05-01

    Full Text Available The present study provides information about the levels of fortification of three water soluble vitamins i.e. thiamine (B1, nicotinamide (B3 and pyridoxine (B6 in a variety of foodstuffs include milk products and cereals for young children. Food fortification is key implement for improving health of the growing children. Twenty food samples were chosen for analysis because of their common utilization in the local area. The vitamin concentrations were determined by high performance liquid chromatography with C18 column with a gradient of mobile phase made of water and acetonitrile and a diode array detector set at 280 nm. The thiamine content investigated in the samples ranging from 268 µg/mL to 3 µg/ml, nicotinamide content was from 41 µg/ml to 1 µg/mL while the pyridoxine level was in between 412 µg/mL to 20 µg/mL. Detection and Quantification of compounds were attained by comparing their retention times with standard reference materials and on the basis the off peak area match against those of a standard. The method used, offer excellent linearity with r2 ≥ 0.994, detection limits, reproducibility, and analyte recovery.

  9. Influence of copper sulphate on the water and electrolyte balance of the freshwater snail Bulinus (Bulinus) tropicus

    Energy Technology Data Exchange (ETDEWEB)

    Van Aardt, W.J. (Potchefstroom University for C.H.E. (South Africa). Dept. of Zoology); Coertze, D.J. (Durban-Westville Univ. (South Africa). Dept of Physiology)

    1981-01-01

    The water and electrolyte balance of Bulinus (Bulinus) tropicus, a freshwater pulmonate, was determined when subjected to different sublethal concentrations of copper sulphate. It was found that the lethal dose (LD/sub 50/), which is the dose lethal to 50% of the snails, is 1,0 ppm in water of pH 8,5. Increasing dosages disturb the ionic and water balance. Haemolymph concentrations of Na+, Ca/sup 2/+ and Cl- decrease markedly. The rates of ion influx and efflux for Ca/sup 2/+, Na+, Cl- and /sup 3/H/sub 2/O, measured with their corresponding radioisotopes, were drastically changed. The results indicate that the physiological effects of copper are not limited to particular organs or tissues but probably occur throughout the snail body. The possible effects of copper sulphate on the integumental exchange mechanisms for Ca/sup 2/+, HCO/sub 3/-, Na+, K+ and Cl- are discussed.

  10. Pore-Network Modeling of Water and Vapor Transport in the Micro Porous Layer and Gas Diffusion Layer of a Polymer Electrolyte Fuel Cell

    NARCIS (Netherlands)

    Qin, C.; Hassanizadeh, S.M.; van Oosterhout, L.M.

    2016-01-01

    In the cathode side of a polymer electrolyte fuel cell (PEFC), a micro porous layer (MPL) added between the catalyst layer (CL) and the gas diffusion layer (GDL) plays an important role in water management. In this work, by using both quasi-static and dynamic pore-network models, water and vapor tra

  11. A ketone/alcohol polymer for cycle of electrolytic hydrogen-fixing with water and releasing under mild conditions

    Science.gov (United States)

    Kato, Ryo; Yoshimasa, Keisuke; Egashira, Tatsuya; Oya, Takahiro; Oyaizu, Kenichi; Nishide, Hiroyuki

    2016-09-01

    Finding a safe and efficient carrier of hydrogen is a major challenge. Recently, hydrogenated organic compounds have been studied as hydrogen storage materials because of their ability to stably and reversibly store hydrogen by forming chemical bonds; however, these compounds often suffer from safety issues and are usually hydrogenated with hydrogen at high pressure and/or temperature. Here we present a ketone (fluorenone) polymer that can be moulded as a plastic sheet and fixes hydrogen via a simple electrolytic hydrogenation at -1.5 V (versus Ag/AgCl) in water at room temperature. The hydrogenated alcohol derivative (the fluorenol polymer) reversibly releases hydrogen by heating (80 °C) in the presence of an aqueous iridium catalyst. Both the use of a ketone polymer and the efficient hydrogen fixing with water as a proton source are completely different from other (de)hydrogenated compounds and hydrogenation processes. The easy handling and mouldable polymers could suggest a pocketable hydrogen carrier.

  12. Enhanced proton transport in nanostructured polymer electrolyte/ionic liquid membranes under water-free conditions.

    Science.gov (United States)

    Kim, Sung Yeon; Kim, Suhan; Park, Moon Jeong

    2010-10-05

    Proton exchange fuel cells (PEFCs) have the potential to provide power for a variety of applications ranging from electronic devices to transportation vehicles. A major challenge towards economically viable PEFCs is finding an electrolyte that is both durable and easily passes protons. In this article, we study novel anhydrous proton-conducting membranes, formed by incorporating ionic liquids into synthetic block co-polymer electrolytes, poly(styrenesulphonate-b-methylbutylene) (S(n)MB(m)), as high-temperature PEFCs. The resulting membranes are transparent, flexible and thermally stable up to 180 °C. The increases in the sulphonation level of S(n)MB(m) co-polymers (proton supplier) and the concentration of the ionic liquid (proton mediator) produce an overall increase in conductivity. Morphology effects were studied by X-ray scattering and electron microscopy. Compared with membranes having discrete ionic domains (including Nafion 117), the nanostructured membranes revealed over an order of magnitude increase in conductivity with the highest conductivity of 0.045 S cm(-1) obtained at 165 °C.

  13. Replication of the Apparent Excess Heat Effect in a Light Water-Potassium Carbonate-Nickel Electrolytic Cell

    Science.gov (United States)

    Niedra, Janis M.; Myers, Ira T.; Fralick, Gustave C.; Baldwin, Richard S.

    1996-01-01

    Replication of experiments claiming to demonstrate excess heat production in light water-Ni-K2CO3 electrolytic cells was found to produce an apparent excess heat of 11 W maximum, for 60 W electrical power into the cell. Power gains range from 1.06 to 1.68. The cell was operated at four different dc current levels plus one pulsed current run at 1 Hz, 10% duty cycle. The 28 liter cell used in these verification tests was on loan from a private corporation whose own tests with similar cells are documented to produce 50 W steady excess heat for a continuous period exceeding hundreds of days. The apparent excess heat can not be readily explained either in terms of nonlinearity of the cell's thermal conductance at a low temperature differential or by thermoelectric heat pumping. However, the present data do admit efficient recombination of dissolved hydrogen-oxygen as an ordinary explanation. Calorimetry methods and heat balance calculations for the verification tests are described. Considering the large magnitude of benefit if this effect is found to be a genuine new energy source, a more thorough investigation of evolved heat in the nickel-hydrogen system in both electrolytic and gaseous loading cells remains warranted.

  14. [Contents of water-soluble vitamins in canned fish and seafood].

    Science.gov (United States)

    Shmakova, S I; Shvidskaia, Z P; Dolbnina, L V

    2000-01-01

    Data of contents of vitamins (B1 and B2, C, PP) in production from gidrobionts is given. Is established, that the process of sterilization of canned food from gidrobionts in to container provides significant (almost twofold) decrease (reduction) of vitamins B1 [symbol: see text] B2, smaller losses of vitamin C (less than 30%) and proves to be true sufficient stability (almost on 85-90%) to action of high temperatures (120 degrees C) of vitamin PP. The canned food from sea gidrobionts represent the certain interest basically as a source of vitamin PP, and canned food "Herring smoked in oil"--vitamin B2. The canned food "Skobljanka from cucumber and fish" can be considered as a source of vitamins B2, C, PP.

  15. Vitamin B1 in marine sediments: pore water concentration gradient drives benthic flux with potential biological implications

    Directory of Open Access Journals (Sweden)

    Danielle eMonteverde

    2015-05-01

    Full Text Available Vitamin B1, or thiamin, can limit primary productivity in marine environments, however the major marine environmental sources of this essential coenzyme remain largely unknown. Vitamin B1 can only be produced by organisms that possess its complete synthesis pathway, while other organisms meet their cellular B1 quota by scavenging the coenzyme from exogenous sources. Due to high bacterial cell density and diversity, marine sediments could represent some of the highest concentrations of putative B1 producers, yet these environments have received little attention as a possible source of B1 to the overlying water column. Here we report the first dissolved pore water profiles of B1 measured in cores collected in two consecutive years from Santa Monica Basin, CA. Vitamin B1 concentrations were fairly consistent between the two years ranging from 30 pM up to 770 pM. A consistent maximum at ~5 cm sediment depth covaried with dissolved concentrations of iron. Pore water concentrations were higher than water column levels and represented some of the highest known environmental concentrations of B1 measured to date, (over two times higher than maximum water column concentrations suggesting increased rates of cellular production and release within the sediments. A one dimensional diffusion-transport model applied to the B1 profile was used to estimate a diffusive benthic flux of ~0.7 nmol m 2 d-1. This is an estimated flux across the sediment-water interface in a deep sea basin; if similar magnitude B-vitamin fluxes occur in shallow coastal waters, benthic input could prove to be a significant B1-source to the water column and may play an important role in supplying this organic growth factor to auxotrophic primary producers.

  16. Seaweed vitamins as nutraceuticals.

    Science.gov (United States)

    Škrovánková, Soňa

    2011-01-01

    Seaweeds are a good source of some water- (B(1), B(2), B(12), C) and fat-soluble (β-carotene with vitamin A activity, vitamin E) vitamins. To ensure that the adequate intake of all vitamins is received in the diet, people (especially people on special diet, strict vegetarians, and vegans) can consume foods enriched with vitamins, for example, in the form of functional foods with vitamins as nutraceuticals, extracted from natural sources such as seaweeds. Seaweed vitamins are important not only due to their biochemical functions and antioxidant activity but also due to other health benefits such as decreasing of blood pressure (vitamin C), prevention of cardiovascular diseases (β-carotene), or reducing the risk of cancer (vitamins E and C, carotenoids). Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Prediction of thermophysical and transport properties of ternary organic non-electrolyte systems including water by polynomials

    Directory of Open Access Journals (Sweden)

    Đorđević Bojan D.

    2013-01-01

    Full Text Available The description and prediction of the thermophysical and transport properties of ternary organic non-electrolyte systems including water by the polynomial equations are reviewed. Empirical equations of Radojković et al. (also known as Redlich-Kister, Kohler, Jacob-Fitzner, Colinet, Tsao-Smith, Toop, Scatchard et al. and Rastogi et al. are compared with experimental data of available papers appeared in well know international journals (Fluid Phase Equilibria, Journal of Chemical and Engineering Data, Journal of Chemical Thermodynamics, Journal of Solution Chemistry, Journal of the Serbian Chemical Society, The Canadian Journal of Chemical Engineering, Journal of Molecular Liquids, Thermochimica Acta, etc.. The applicability of empirical models to estimate excess molar volumes, VE, excess viscosities, ηE, excess free energies of activation of a viscous flow,

  18. Muscle alkali-soluble protein, carnitine, water and electrolytes in patients with persistent post-operative infection.

    Science.gov (United States)

    Soop, M; Forsberg, E; Thörne, A; Cederblad, G; Bergström, J; Forsberg, A M; Hultman, E

    1989-10-01

    The muscle contents of water, electrolytes, creatine, alkali-soluble protein (ASP) and carnitine were determined using percutaneous muscle biopsy technique. Seven patients with prolonged catabolic states and subsequent respiratory failure were studied. Twelve age- and sex-matched healthy subjects were used for comparison. The muscle content of alkali-soluble protein in relation to the content of DNA was less than half of control values, indicating a loss of more than 50% of muscle protein content. The muscle carnitine content was 25.9 +/- 6.5 mumol/g alkali-soluble protein, suggesting a preserved muscle carnitine concentration. Total muscle water was increased by over 20%, mainly due to an increase in extracellular water. Muscle sodium and chloride contents were doubled. The content of magnesium was slightly reduced but muscle potassium was normal. The marked depletion of muscle protein may have contributed to the requirements for artificial ventilation and the difficulties in weaning off the ventilator. The increase in muscle water masks the loss of metabolically active muscle tissue yielding low values for energy expenditure when relating to body weight. The benefit of the use of the ASP/DNA ratio in nutritional assessment is emphasised.

  19. [Water and electrolyte content of the organs and tissues of male rats following a flight on the Kosmos 1667 biosatellite].

    Science.gov (United States)

    Denisova, L A; Lavrova, E A; Natochin, Iu V; Serova, L V

    1988-01-01

    After the 7-day space flight onboard the biosatellite Cosmos-1667 the water, Na, K, Ca and Mg content of the liver, kidney, heart, skin and bone of male rats was measured. No significant changes in the weight or water content of the above organs were seen. The exception was a decrease of water contained in the heart and an increase of water contained in the caudal appendage of the epididymis. After flight the mineral composition of the liver was identical to that after control studies. The K content of the heart of the flight rats was lower and that of Na, Ca and Mg was identical to the parameter in the controls. The K content of the skin and bone increased and the Na content of the skin also grew. In the kidney the Ca content did not change whereas the content of K, Na and Mg decreased significantly. In the testis Na decreased and K increased after flight. Thus, changes in fluid-electrolyte homeostasis at the organ and tissue level can develop within 7 days of space flight. They occur not only in the musculoskeletal system but may also evolve in the nonweight-bearing organs.

  20. 电解氧化-AF-MBBR处理维生素C生产废水%Advanced treatment of vitamin C wastewater by electrolytic oxidation and AF-MBBR integrated reactor

    Institute of Scientific and Technical Information of China (English)

    王钊; 胡小兵; 许柯; 任洪强; 郑巧庚

    2011-01-01

    Advanced treatment of the effluent from anaerobic-aerobic biological treatment of vitamin C wastewater with electrolytic oxidation coupled with AF-MBBR integrated reactor was studied. Electrolytic oxidation was effective for decolorization, and the optimal operation conditions were as following: pH of 4, current density of 50 mA/cm2, electrolysis time of 15 min, and the distance of electrodes of 25 mm. Under these conditions, the TOC and chroma of effluents were 97.6~123.2mg/L and 135-155 times respectively. The ratio of BOD5/COD increased from less than 0.1 to about 0.24. Upon pretreatment, the effluent was further treated through AF-MBBR integrated reactor. The TOC, chroma and NH4+-N decreased to 57.18mg/L, 60 times and 2.55mg/L respectively, which primarily discharge met the standards (GB 21903-2008) for fermentation pharmaceutical industry, verifying the feasibility of the combined treatment process for advanced treatment of vitamin C wastewater. The optimum HRT of the integrated reactor was 10h. The addition of 100 mg/L glucose substantially enhanced denitrification and more than 78.1% of TN was removed. It showed that glucose could be used as the appropriate carbon resource for denitrification for advanced treatment of vitamin C wastewater. In addition, ultraviolet and infrared analysis showed that the chromophore was mainly from the carbonyl groups, which could be broken by the electrolytic oxidation and the AF-MBBR biological treatment.%采用电解氧化和厌氧生物滤池-好氧移动床生物膜(AF-MBBR)一体化反应器组合工艺对维生素C生产企业的二级生化出水进行深度处理.结果表明,电解氧化预处理具有较好的脱色效果,优化的运行条件为:pH值为4、电流密度50mA/cm2、极板间距25mm、电解时间15min.此时出水TOC降为97.6~ 123.2mg/L、色度降为135~155倍、BOD√COD从不足0.1提高到0.24左右.出水进入AF-MBBR一体化反应器处理,出水平均TOC、色度和氨氮可分别降至57

  1. Molecular dynamics simulations of triflic acid and triflate ion/water mixtures: a proton conducting electrolytic component in fuel cells.

    Science.gov (United States)

    Sunda, Anurag Prakash; Venkatnathan, Arun

    2011-11-30

    Triflic acid is a functional group of perflourosulfonated polymer electrolyte membranes where the sulfonate group is responsible for proton conduction. However, even at extremely low hydration, triflic acid exists as a triflate ion. In this work, we have developed a force-field for triflic acid and triflate ion by deriving force-field parameters using ab initio calculations and incorporated these parameters with the Optimized Potentials for Liquid Simulations - All Atom (OPLS-AA) force-field. We have employed classical molecular dynamics (MD) simulations with the developed force field to characterize structural and dynamical properties of triflic acid (270-450 K) and triflate ion/water mixtures (300 K). The radial distribution functions (RDFs) show the hydrophobic nature of CF(3) group and presence of strong hydrogen bonding in triflic acid and temperature has an insignificant effect. Results from our MD simulations show that the diffusion of triflic acid increases with temperature. The RDFs from triflate ion/water mixtures shows that increasing hydration causes water molecules to orient around the SO(3)(-) group of triflate ions, solvate the hydronium ions, and other water molecules. The diffusion of triflate ions, hydronium ion, and water molecules shows an increase with hydration. At λ = 1, the diffusion of triflate ion is 30 times lower than the diffusion of triflic acid due to the formation of stable triflate ion-hydronium ion complex. With increasing hydration, water molecules break the stability of triflate ion-hydronium ion complex leading to enhanced diffusion. The RDFs and diffusion coefficients of triflate ions, hydronium ions and water molecules resemble qualitatively the previous findings using per-fluorosulfonated membranes.

  2. Effects of feeding and short-term fasting on water and electrolyte turnover in female mink (Mustela vison).

    Science.gov (United States)

    Wamberg, S; Tauson, A H; Elnif, J

    1996-11-01

    Daily (24 h) rates of water and electrolyte turnover were measured in a conventional balance study in ten adult female pastel mink (Mustela vison) given free access to a standard mink feed for a 1-week conditioning period, followed by a 4 d experimental period and a 2 d fasting period. Drinking water was available throughout. In addition, the completeness of urine collection and the fraction of urine collected with the faeces were determined using a new experimental technique based on 24 h recoveries of specific urinary markers such as tritiated p-aminohippuric acid ([3H]PAH) or 14C-labelled inulin ([14C]IN) continuously delivered by small Alzet osmotic pumps implanted intraperitoneally. During feeding the mean individual percentage recovery in urine of [3H]PAH released from the osmotic pumps ranged from 68 to 88% (median 78%). The mean percentage of urinary [3H]PAH recovered from faecal collections was 6% (range 3-12%). In response to fasting the mean individual percentage recovery of [3H]PAH in urine ranged from 62 to 78% (median 68%). For urinary [14C]IN the mean percentage recoveries in fed and fasted animals were 79 and 63% respectively. Furthermore, during fasting, withdrawal of the supplies of dietary water caused a slight but insignificant (P = 0.17) increase in the daily intake of drinking water and, hence, the animals maintained their normal water balance by a dramatic reduction in urine excretion (P < 0.001). At the same time urinary solute excretion declined significantly (P < 0.001), due in part to the cessation of dietary electrolyte intake and in part to reduced formation of urea, whereas urinary osmolality decreased only moderately. The mean 24 h balances of Na, K, Ca, Mg, Cl and P were close to zero and only minor differences between the feeding and fasting periods were observed. When corrected for the measured inaccuracies in urine collection the balance data obtained in the present study represent useful reference standards for normally fed and

  3. Modeling the Liquid Water Transport in the Gas Diffusion Layer for Polymer Electrolyte Membrane Fuel Cells Using a Water Path Network

    Directory of Open Access Journals (Sweden)

    Dietmar Gerteisen

    2013-09-01

    Full Text Available In order to model the liquid water transport in the porous materials used in polymer electrolyte membrane (PEM fuel cells, the pore network models are often applied. The presented model is a novel approach to further develop these models towards a percolation model that is based on the fiber structure rather than the pore structure. The developed algorithm determines the stable liquid water paths in the gas diffusion layer (GDL structure and the transitions from the paths to the subsequent paths. The obtained water path network represents the basis for the calculation of the percolation process with low calculation efforts. A good agreement with experimental capillary pressure-saturation curves and synchrotron liquid water visualization data from other literature sources is found. The oxygen diffusivity for the GDL with liquid water saturation at breakthrough reveals that the porosity is not a crucial factor for the limiting current density. An algorithm for condensation is included into the model, which shows that condensing water is redirecting the water path in the GDL, leading to an improved oxygen diffusion by a decreased breakthrough pressure and changed saturation distribution at breakthrough.

  4. Sulphonated imidized graphene oxide (SIGO) based polymer electrolyte membrane for improved water retention, stability and proton conductivity

    Science.gov (United States)

    Pandey, Ravi P.; Shahi, Vinod K.

    2015-12-01

    Sulphonated imidized graphene oxide (SIGO) (graphene oxide (GO) tethered sulphonated polyimide) has been successfully synthesized by polycondensation reaction using dianhydride and sulphonated diamine. Polymer electrolyte membranes (PEMs) are prepared by using SIGO (different wt%) and sulphonated poly(imide) (SPI). Resultant SPI/SIGO composite PEMs exhibit improved stabilities (thermal, mechanical and oxidative) and good water-retention properties (high bound water content responsible for proton conduction at high temperature by internal self-humidification). Incorporation of covalent bonded SIGO into SPI matrix results hydrophobic-hydrophilic phase separation and facile architecture of proton conducting path. Well optimized sulphonated poly(imide)/sulphonated imidized graphene oxide (15 wt%) (SPI/SIGO-15) composite membrane shows 2.24 meq g-1 ion-exchange capacity (IEC); 11.38 × 10-2 S cm-1 proton conductivity; 5.12% bound water content; and 10.52 × 10-7 cm2 s-1 methanol permeability. Maximum power density for pristine SPI membrane (57.12 mW cm-2) improves to 78.53 mW cm-2 for SPI/SIGO-15 membrane, in single-cell direct methanol fuel cell (DMFC) test at 70 °C using 2 M methanol fuel. Under similar experimental conditions, Nafion 117 membrane exhibits 62.40 mW cm-2 maximum power density. Reported strategy for the preparation of PEMs, offers a useful protocol for grafting of functionalized inorganic materials with in organic polymer chain by imidization.

  5. Advanced control of liquid water region in diffusion media of polymer electrolyte fuel cells through a dimensionless number

    Science.gov (United States)

    Wang, Yun; Chen, Ken S.

    2016-05-01

    In the present work, a three-dimension (3-D) model of polymer electrolyte fuel cells (PEFCs) is employed to investigate the complex, non-isothermal, two-phase flow in the gas diffusion layer (GDL). Phase change in gas flow channels is explained, and a simplified approach accounting for phase change is incorporated into the fuel cell model. It is found that the liquid water contours in the GDL are similar along flow channels when the channels are subject to two-phase flow. Analysis is performed on a dimensionless parameter Da0 introduced in our previous paper [Y. Wang and K. S. Chen, Chemical Engineering Science 66 (2011) 3557-3567] and the parameter is further evaluated in a realistic fuel cell. We found that the GDL's liquid water (or liquid-free) region is determined by the Da0 number which lumps several parameters, including the thermal conductivity and operating temperature. By adjusting these factors, a liquid-free GDL zone can be created even though the channel stream is two-phase flow. Such a liquid-free zone is adjacent to the two-phase region, benefiting local water management, namely avoiding both severe flooding and dryness.

  6. Enhancing the efficacy of electrolytic chlorination for ballast water treatment by adding carbon dioxide.

    Science.gov (United States)

    Cha, Hyung-Gon; Seo, Min-Ho; Lee, Heon-Young; Lee, Ji-Hyun; Lee, Dong-Sup; Shin, Kyoungsoon; Choi, Keun-Hyung

    2015-06-15

    We examined the synergistic effects of CO2 injection on electro-chlorination in disinfection of plankton and bacteria in simulated ballast water. Chlorination was performed at dosages of 4 and 6ppm with and without CO2 injection on electro-chlorination. Testing was performed in both seawater and brackish water quality as defined by IMO G8 guidelines. CO2 injection notably decreased from the control the number of Artemia franciscana, a brine shrimp, surviving during a 5-day post-treatment incubation (1.8 and 2.3 log10 reduction in seawater and brackish water, respectively at 6ppm TRO+CO2) compared with water electro-chlorinated only (1.2 and 1.3 log10 reduction in seawater and brackish water, respectively at 6ppm TRO). The phytoplankton Tetraselmis suecica, was completely disinfected with no live cell found at >4ppm TRO with and without CO2 addition. The effects of CO2 addition on heterotrophic bacterial growth was not different from electro-chlorination only. Total residual oxidant concentration (TRO) more rapidly declined in electro-chlorination of both marine and brackish waters compared to chlorine+CO2 treated waters, with significantly higher amount of TRO being left in waters treated with the CO2 addition. Total concentration of trihalomethanes (THMs) and haloacetic acids (HAAs) measured at day 0 in brackish water test were found to be 2- to 3-fold higher in 6ppm TRO+CO2-treated water than in 6ppm TRO treated water. The addition of CO2 to electro-chlorination may improve the efficiency of this sterilizing treatment of ballast water, yet the increased production of some disinfection byproducts needs further study.

  7. Electrolytic oxidation of anthracite

    Science.gov (United States)

    Senftle, F.E.; Patton, K.M.; Heard, I.

    1981-01-01

    An anthracite slurry can be oxidized only with difficulty by electrolytic methods in which aqueous electrolytes are used if the slurry is confined to the region of the anode by a porous pot or diaphragm. However, it can be easily oxidized if the anthracite itself is used as the anode. No porous pot or diaphragm is needed. Oxidative consumption of the coal to alkali-soluble compounds is found to proceed preferentially at the edges of the aromatic planes. An oxidation model is proposed in which the chief oxidants are molecular and radical species formed by the electrolytic decomposition of water at the coal surface-electrolyte interface. The oxidation reactions proposed account for the opening of the aromatic rings and the subsequent formation of carboxylic acids. The model also explains the observed anisotropic oxidation and the need for the porous pot or diaphragm used in previous studies of the oxidation of coal slurries. ?? 1981.

  8. Avaliação em escala laboratorial da utilização do processo eletrolítico no tratamento de águas Laboratory scale assessment of an electrolytic process for water treatment

    Directory of Open Access Journals (Sweden)

    Marcelo Henrique Otenio

    2008-01-01

    Full Text Available Water treatment uses chlorine for disinfection causing formation of trihalomethanes. In this work, an electrolytic water pre-treatment was studied and applied to the water from a fountainhead. The action against microorganisms was evaluated using cast-iron and aluminum electrodes. Assays were made in laboratory using the electrolytic treatment. After 5 min of electrolysis the heterotrophic bacteria count was below 500 cfu/mL and complete elimination of total and fecal coliforms was observed. Using electrolytic treatment as a pretreatment of conventional tap water treatment is proposed.

  9. High resolution neutron imaging of water in the polymer electrolyte membrane

    Energy Technology Data Exchange (ETDEWEB)

    Spernjak, Dusan [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Spendelow, Jacob S [Los Alamos National Laboratory; Davey, John [Los Alamos National Laboratory; Fairweather, Joseph [Los Alamos National Laboratory; Mukherjee, Partha [ORNL

    2010-01-01

    To achieve a deeper understanding of water transport and performance issues associated with water management, we have conducted in situ water examinations to help understand the effects of components and operation. High Frequency Resistance (HFR), AC Impedance and neutron radiography were used to measure water content in operating fuel cells under various operating conditions. Variables examined include: sub-freezing conditions, inlet relative humidities, cell temperature, current density and response transients, different flow field orientations and different component materials (membranes, GDLs and MEAs). Quantification of the water within the membrane was made by neutron radiography after equilibration to different humidified gases, during fuel cell operation and in hydrogen pump mode. The water content was evaluated in bare Nafion{reg_sign} membranes as well as in MEAs operated in both fuel cell and H{sub 2} pump mode. These in situ imaging results allow measurement of the water content and gradients in the PEFC membrane and relate the membrane water transport characteristics to the fuel cell operation and performance under disparate materials and operational combinations. Flow geometry makes a large impact on MEA water content. Higher membrane water with counter flow was measured compared with co-flow for sub-saturated inlet RH's. This correlates to lower HFR and higher performance compared with co-flow. Higher anode stoichiometry helps remove water which accumulates in the anode channels and GDL material. Cell orientation was measured to affect both the water content and cell performance. While membrane water content was measured to be similar regardless of orientation, cells with the cathode on top show flooding and loss of performance compared with similarly operated cells with the anode on top. Transient fuel cell current measurements show a large degree of hysteresis in terms of membrane hydration as measured by HFR. Current step transients from 0

  10. On water transport in polymer electrolyte membranes during the passage of current

    DEFF Research Database (Denmark)

    Berning, Torsten

    2011-01-01

    This article discusses an approach to model the water transport in the membranes of PEM fuel cells during operation. Starting from a frequently utilized equation the various transport mechanisms are analyzed in detail. It is shown that the commonly used approach to simply balance the electro-osmotic...... drag (EOD) with counter diffusion and/or hydraulic permeation is flawed, and that any net transport of water through the membrane is caused by diffusion. Depending on the effective drag the cathode side of the membrane may experience a lower hydration than the anode side. The effect of a water......-uptake layer on the net water transport will also be pictured. Finally, the effect of EOD is visualized using “Newton’s cradle”....

  11. Development of Electrolytic Active Chlorine Disinfection in Water Treatment%电解活性氯杀菌在水处理中的研究进展

    Institute of Scientific and Technical Information of China (English)

    张化冰; 郦和生

    2014-01-01

    Electrolytic active chlorine disinfection is efficient ,cost -effective and environmental friendly .It works without the addition of chemical compounds to the water ,and its effectiveness of water disinfection is clear without increasing the concentration of chloride ions in water . This article summarizes the disinfection mechanism , electrolytic process and application of this technique .%指出了电解活性氯杀菌是一种高效率、低成本、对环境友好的杀菌技术,该技术无需添加化学药剂,在不增加水中氯离子浓度的情况下,起到杀菌作用。对其杀菌机理、电解工艺和应用情况进行了总结。

  12. DEVELOPMENT AND VALIDATION OF UV-VISIBLE SPECTROMETRIC METHOD FOR ESTIMATION OF WATER SOLUBLE VITAMIN RIBOFLAVIN

    Directory of Open Access Journals (Sweden)

    Himanshi Shah et al

    2012-09-01

    Full Text Available The present study describes a simple, accurate, precise and cost effective UV-Visible spectrophotometric method for the estimation of Riboflavin raw material. The Riboflavin is water soluble vitamin, so the solvent used throughout the experiment was 0.1N NaOH, the absorption maxima of drug was found at 445 nm. Beer’s law was obeyed in the range of 5ppm-30ppm. the developed method was successfully validated with respect to linearity, accuracy and precision. The method was validated and shown linearity in mentioned concentration. The correlation coefficient for Riboflavin was 0.999. The percentage relative standard deviation of inter-day precision range 0.66-1.04% and intra-day precision 1.05-1.39% both should be less than 2%. Hence proposed method was precise, accurate and cost effective, simple and rapid. This validated method can be applicable for quantitative determination of the titled drug with respect to assay from or for their solid dosage forms.

  13. Solid polymer electrolyte water electrolysis preprototype subsystem. [oxygen production for life support systems on space stations

    Science.gov (United States)

    1979-01-01

    Hardware and controls developed for an electrolysis demonstration unit for use with the life sciences payload program and in NASA's regenerative life support evaluation program are described. Components discussed include: the electrolysis module; power conditioner; phase separator-pump and hydrogen differential regulator; pressure regulation of O2, He, and N2; air-cooled heat exchanger; water accumulator; fluid flow sight gage assembly; catalytic O2/H2 sensor; gas flow sensors; low voltage power supply; 100 Amp DC contactor assembly; and the water purifier design.

  14. On water transport in polymer electrolyte membranes during the passage of current

    DEFF Research Database (Denmark)

    Berning, Torsten

    2011-01-01

    This article discusses an approach to model the water transport in the membranes of PEM fuel cells during operation. Starting from a frequently utilized equation the various transport mechanisms are analyzed in detail. It is shown that the commonly used approach to simply balance the electro-osmo...

  15. Fundamental aspects of oily waters treatment from the mineral industries by electrolytic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Merma, A.G.; Gonzales, L.V.; Torem, M.L. [Pontifical Catholic Univ. of Rio de Janeiro, Rio de Janeiro (Brazil). Dept. of Materials Engineering

    2010-07-01

    There is an immediate need to develop innovative and more effective techniques for treatment of wastewaters as regulations on effluent wastewater discharge are becoming increasingly prevalent. The mining and metallurgical industries generate wastewaters that contain stable oil-in-water emulsions, arising from residues of liquid streams that serve the purpose of lubrication, cooling, cleaning and corrosion prevention in the equipment used in those industries. Chemically stabilized oil-water emulsions produced in the mineral industries can be treated using an electrocoagulation technique that considers the effects of operating parameters such as initial pH, current density, reaction time, electrode area/liquid volume ratio and electrode materials on the separation of oil as measured by the chemical oxygen demand. The paper discussed electrocoagulation as well as the materials and methods for the study, including oil in water emulsions; the experimental apparatus; and the experimental procedure. It was concluded that the electrolysis of this kind of oil in water emulsions with aluminum electrodes resulted in pH neutralization regardless of the initial pH tested. 18 refs., 4 figs.

  16. Polymer Electrolyte Fuel Cells Membrane Hydration by Direct Liquid Water Contact

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.S.; Zawodzinski, C.; Gottesfeld, S.

    1998-11-01

    An effective means of providing direct liquid hydration of the membrane tends to improve performance particularly of cells with thicker membranes or at elevated temperatures. Supplying the water to the membrane from the anode flow-field through the anode backing via wicks would appear to have advantages over delivering the water through the thickness of the membrane with regards to the uniformity and stability of the supply and the use of off-the-shelf membranes or MEAs. In addition to improving cell performance, an important contribution of direct liquid hydration approaches may be that the overall fuel cell system becomes simpler and more effective. The next steps in the evolution of this approach are a demonstration of the effectiveness of this technique with larger active area cells as well as the implementation of an internal flow-field water reservoir (to eliminate the injection method). Scale-up to larger cell sizes and the use of separate water channels within the anode flow-field is described.

  17. Water Uptake and Acid Doping of Polybenzimidazoles as Electrolyte Membranes for Fuel Cells

    DEFF Research Database (Denmark)

    Qingfeng, Li; He, R.; Berg, Rolf W.

    2004-01-01

    Acid-doped polybenzimidazole (PBI) membranes have been demonstrated for fuel cell applications with advanced features such as high operating temperatures, little humidification, excellent CO tolerance, and promising durability. The water uptake and acid doping of PBI membranes have been studied. ...

  18. Decoupling hydrogen and oxygen evolution during electrolytic water splitting using an electron-coupled-proton buffer.

    Science.gov (United States)

    Symes, Mark D; Cronin, Leroy

    2013-05-01

    Hydrogen is essential to several key industrial processes and could play a major role as an energy carrier in a future 'hydrogen economy'. Although the majority of the world's hydrogen supply currently comes from the reformation of fossil fuels, its generation from water using renewables-generated power could provide a hydrogen source without increasing atmospheric CO₂ levels. Conventional water electrolysis produces H₂ and O₂ simultaneously, such that these gases must be generated in separate spaces to prevent their mixing. Herein, using the polyoxometalate H₃PMo₁₂O₄₀, we introduce the concept of the electron-coupled-proton buffer (ECPB), whereby O₂ and H₂ can be produced at separate times during water electrolysis. This could have advantages in preventing gas mixing in the headspaces of high-pressure electrolysis cells, with implications for safety and electrolyser degradation. Furthermore, we demonstrate that temporally separated O₂ and H₂ production allows greater flexibility regarding the membranes and electrodes that can be used in water-splitting cells.

  19. The influence of membrane electrode assembly water content on the performance of a polymer electrolyte membrane fuel cell as investigated by 1H NMR microscopy.

    Science.gov (United States)

    Feindel, Kirk W; Bergens, Steven H; Wasylishen, Roderick E

    2007-04-21

    The relation between the performance of a self-humidifying H(2)/O(2) polymer electrolyte membrane fuel cell and the amount and distribution of water as observed using (1)H NMR microscopy was investigated. The integrated (1)H NMR image signal intensity (proportional to water content) from the region of the polymer electrolyte membrane between the catalyst layers was found to correlate well with the power output of the fuel cell. Several examples are provided which demonstrate the sensitivity of the (1)H NMR image intensity to the operating conditions of the fuel cell. Changes in the O(2)(g) flow rate cause predictable trends in both the power density and the image intensity. Higher power densities, achieved by decreasing the resistance of the external circuit, were found to increase the water in the PEM. An observed plateau of both the power density and the integrated (1)H NMR image signal intensity from the membrane electrode assembly and subsequent decline of the power density is postulated to result from the accumulation of H(2)O(l) in the gas diffusion layer and cathode flow field. The potential of using (1)H NMR microscopy to obtain the absolute water content of the polymer electrolyte membrane is discussed and several recommendations for future research are provided.

  20. Determination of membrane degradation products in the product water of polymer electrolyte membrane fuel cells using liquid chromatography mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zedda, Marco

    2011-05-12

    The predominant long term failure of polymer electrolyte membranes (PEM) is caused by hydroxyl radicals generated during fuel cell operation. These radicals attack the polymer, leading to chain scission, unzipping and consequently to membrane decomposition products. The present work has investigated decomposition products of novel sulfonated aromatic hydrocarbon membranes on the basis of a product water analysis. Degradation products from the investigated membrane type and the possibility to detect these compounds in the product water for diagnostic purposes have not been discovered yet. This thesis demonstrates the potential of solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) for the extraction, separation, characterization, identification and quantification of membrane degradation products in the product water of fuel cells. For this purpose, several polar aromatic hydrocarbons with different functional groups were selected as model compounds for the development of reliable extraction, separation and detection methods. The results of this thesis have shown that mixed mode sorbent materials with both weak anion exchange and reversed phase retention properties are well suited for reproducible extraction of both molecules and ions from the product water. The chromatographic separation of various polar aromatic hydrocarbons was achieved by means of phase optimized liquid chromatography using a solvent gradient and on a C18 stationary phase. Sensitive and selective detection of model compounds could be successfully demonstrated by the analysis of the product water using tandem mass spectrometry. The application of a hybrid mass spectrometer (Q Trap) for the characterization of unknown polar aromatic hydrocarbons has led to the identification and confirmation of 4-hydroxybenzoic acid in the product water. In addition, 4-HBA could be verified as a degradation product resulting from PEM decomposition by hydroxyl radicals using an

  1. Thermodynamics of the sorption of water-soluble vitamins in reverse-phase high performance liquid chromatography

    Science.gov (United States)

    Chirkin, V. A.; Karpov, S. I.; Selemenev, V. F.

    2012-12-01

    The thermodynamics of the sorption of certain water-soluble vitamins on a C18 reverse phase from water-acetonitrile solutions of different compositions is studied. The thermodynamic characteristics of the investigated chromatographic systems are calculated. The dependences of standard molar enthalpy and changes in entropy when the sorbate transfers from the bulk solution to the surface layer on the concentration of the organic component in the mobile phase are analyzed. The boundaries for applying the main retention models describing the sorption of the investigated compounds are discussed.

  2. Performance equations for cathodes in polymer electrolyte fuel cells with non-uniform water flooding in gas diffusers

    Science.gov (United States)

    Hsuen, Hsiao-Kuo

    The performance equations for cathodes of polymer electrolyte fuel cells (PEFCs) that describe the dependence of cathode potential on current density are developed. Formulation of the performance equations starts from the reduction of a one-dimensional model that considers, in detail, the potential losses pertinent to the limitations of electron conduction, oxygen diffusion, proton migration, and the oxygen reduction reaction. In particular, non-uniform accumulation of liquid water in the gas diffuser, which partially blocks the gas channels and imposes a greater resistance for oxygen transport, is taken into account. Reduction of the one-dimensional model is implemented by approximating the oxygen concentration profile in the catalyst layer with a parabolic polynomial or a piecewise parabolic one determined by the occurrence of oxygen depletion. The final forms of the equations are obtained by applying the method of weighted residuals over the catalyst layer. The weighting function is selected in such a way that the weighted residuals can be analytically integrated. Potential losses caused by the various limiting processes can be quantitatively estimated by the performance equations. Thus, they provide a convenient diagnostic tool for the cathode performance. Computational results reveal that the performance equations agree well with the original one-dimensional model over an extensive range of parameter values. This indicates that the present performance equations can be used as a substitute for the one-dimensional model to provide quantitatively correct predictions for the cathode performance of PEFCs.

  3. Preparation and physicochemical properties of surfactant-free emulsions using electrolytic-reduction ion water containing lithium magnesium sodium silicate.

    Science.gov (United States)

    Okajima, Masahiro; Wada, Yuko; Hosoya, Takashi; Hino, Fumio; Kitahara, Yoshiyasu; Shimokawa, Ken-ichi; Ishii, Fumiyoshi

    2013-04-01

    Surfactant-free emulsions by adding jojoba oil, squalane, olive oil, or glyceryl trioctanoate (medium chain fatty acid triglycerides, MCT) to electrolytic-reduction ion water containing lithium magnesium sodium silicate (GE-100) were prepared, and their physiochemical properties (thixotropy, zeta potential, and mean particle diameter) were evaluated. At an oil concentration of 10%, the zeta potential was ‒22.3 ‒ ‒26.8 mV, showing no marked differences among the emulsions of various types of oil, but the mean particle diameters in the olive oil emulsion (327 nm) and MCT emulsion (295 nm) were smaller than those in the other oil emulsions (452-471 nm). In addition, measurement of the hysteresis loop area of each type of emulsion revealed extremely high thixotropy of the emulsion containing MCT at a low concentration and the olive emulsion. Based on these results, since surfactants and antiseptic agents markedly damage sensitive skin tissue such as that with atopic dermatitis, surfactant- and antiseptic-free emulsions are expected to be new bases for drugs for external use.

  4. Stability and Degradation Mechanisms of Radiation-Grafted Polymer Electrolyte Membranes for Water Electrolysis.

    Science.gov (United States)

    Albert, Albert; Lochner, Tim; Schmidt, Thomas J; Gubler, L

    2016-06-22

    Radiation-grafted membranes are a promising alternative to commercial membranes for water electrolyzers, since they exhibit lower hydrogen crossover and area resistance, better mechanical properties, and are of potentially lower cost than perfluoroalkylsulfonic acid membranes, such as Nafion. Stability is an important factor in view of the expected lifetime of 40 000 h or more of an electrolyzer. In this study, combinations of styrene (St), α-methylstyrene (AMS), acrylonitrile (AN), and 1,3-diisopropenylbenzene (DiPB) are cografted into 50 μm preirradiated poly(ethylene-co-tetrafluoroethylene) (ETFE) base film, followed by sulfonation to produce radiation-grafted membranes. The stability of the membranes with different monomer combinations is compared under an accelerated stress test (AST), and the degradation mechanisms are investigated. To mimic the conditions in an electrolyzer, in which the membrane is always in contact with liquid water at elevated temperature, the membranes are immersed in water for 5 days at 90 °C, so-called thermal stress test (TST). In addition to testing in air atmosphere tests are also carried out under argon to investigate the effect of the absence of oxygen. The water is analyzed with UV-vis spectroscopy and ion chromatography. The ion exchange capacity (IEC), swelling degree, and Fourier transform infrared (FTIR) spectra of the membranes are compared before and after the test. Furthermore, energy-dispersive X-ray (EDX) spectroscopic analysis of the membrane cross-section is performed. Finally, the influence of the TST to the membrane area resistance and hydrogen crossover is measured. The stability increases along the sequence St/AN, St/AN/DiPB, AMS/AN, and AMS/AN/DiPB grafted membrane. The degradation at the weak-link, oxygen-induced degradation, and hydrothermal degradation are proposed in addition to the "swelling-induced detachment" reported in the literature. By mitigating the possible paths of degradation, the AMS

  5. A study of alternative methods for reclaiming oxygen from carbon dioxide and water by a solid-electrolyte process for spacecraft applications

    Science.gov (United States)

    1971-01-01

    Two alternative technical approaches were studied for application of an electrochemical process using a solid oxide electrolyte (zirconia stabilized by yttria or scandia) to oxygen reclamation from carbon dioxide and water, for spacecraft life support systems. Among the topics considered are the advisability of proceeding to engineering prototype development and fabrication of a full scale model for the system concept, the optimum choice of method or approach to be carried into prototype development, and the technical problem areas which exist.

  6. Modeling and simulations of polymer electrolyte membrane fuel cells with poroelastic approach for coupled liquid water transport and deformation in the membrane

    OpenAIRE

    2010-01-01

    Performance degradation and durability of polymer electrolyte membrane (PEM) fuel cells depend strongly on transport and deformation characteristics of their components especially the polymer membrane. Physical properties of membranes, such as ionic conductivity and Young's modulus, depend on the water content that varies significantly with operating conditions and during transients. Recent studies indicate that cyclic transients may induce hygrothermal fatigue that leads to the ultimate fail...

  7. On the influence of molecular structure on the conductivity of electrolyte solutions - sodium nitrate in water

    Directory of Open Access Journals (Sweden)

    H. Krienke

    2013-01-01

    Full Text Available Theoretical calculations of the conductivity of sodium nitrate in water are presented and compared with experimental measurements. The method of direct correlation force in the framework of the interionic theory is used for the calculation of transport properties in connection with the associative mean spherical approximation (AMSA. The effective interactions between ions in solutions are derived with the help of Monte Carlo and Molecular Dynamics calculations on the Born-Oppenheimer level. This work is based on earlier theoretical and experimental studies of the structure of concentrated aqueous sodium nitrate solutions.

  8. TOTAL PARENTERAL NUTRITION (TPN: ROLE OF RIBOFLAVIN (VITAMIN B2 AND CYANOCOBALAMIN (VITAMIN B12

    Directory of Open Access Journals (Sweden)

    Samina Shiekh

    2015-06-01

    Full Text Available Total parenteral nutrition (TPN replaces and maintains essential nutrients in patients in whom oral or tube feedings are contraindicated or inadequate. A nutritional assessment must be carried out before initiating TPN in order to determine nutritional needs and any metabolic changes due to the patient’s underlying condition, medications or concurrent therapies. In addition to carbohydrates, proteins and fats, certain amounts of micronutirents are also added to TPN solutions. These micronutrients include electrolytes, vitamins, and trace minerals. This review highlights some basic concepts regarding the use and formulation of TPNs along with their advantages and disadvantages and the importance of water soluble vitamins B2 and B12 in human nutrition.

  9. Effect of Drought Stress on Leaf Water Status, Electrolyte Leakage, Photosynthesis Parameters and Chlorophyll Fluorescence of Two Kochia Ecotypes (Kochia scoparia Irrigated With Saline Water

    Directory of Open Access Journals (Sweden)

    A Masoumi

    2012-12-01

    Full Text Available Rainfall deficiency and the development of salinity in Iran are the most important factors for using new salt and drought-resistant plants instead of conventional crops. Kochia species have recently attracted the attention of researchers as a forage and fodder crop in marginal lands worldwide due to its drought and salt tolerant characteristics. This field experiment was performed at the Salinity Research Station of Ferdowsi University of Mashhad, Iran, in a split plot based on randomized complete block design with three replications in 2008. Drought stress, including four levels (control, no irrigation in vegetative stage, no irrigation at reproductive stage and no irrigation at maturity stage for four weeks, and two Kochia ecotypes (Birjand and Borujerd were allocated as main and sub plots, respectively. Relative water content, electrolyte leakage, photosynthesis parameters and chlorophyll fluorescence were assayed every two week from late vegetative stage. Results showed that drought stress decreased significantly measured parameters in plants under stress, in all stages. Plants completely recovered after eliminating stress and rewatering and recovered plants did not show significant difference with control. Electrolyte leaking and chlorophyll fluorescence showed the lowest change among the measured parameters. It can emphasize that resistant to stress conditions in this plant and cell wall is not damaged at this level of stress situation. Birjand ecotype from the arid region, revealed a better response than Borujerd ecotype to drought stress. Probably it returns to initial adaptation of Birjand. In general this plant can recover after severe drought stress well. It is possible to introduce this plant as a new fodder in arid and saline conditions.

  10. Effect of a multistage ultraendurance triathlon on aldosterone, vasopressin, extracellular water and urine electrolytes.

    Science.gov (United States)

    Knechtle, B; Morales, N P Hernández; González, E Ruvalcaba; Gutierrez, A A Aguirre; Sevilla, J Noriega; Gómez, R Amézquita; Robledo, A R Estrada; Rodríguez, A L Marroquín; Fraire, O Salas; Andonie, J L; Lopez, L C; Kohler, G; Rosemann, T

    2012-02-01

    Prolonged endurance exercise over several days induces increase in extracellular water (ECW). We aimed to investigate an association between the increase in ECW and the change in aldosterone and vasopressin in a multistage ultraendurance triathlon, the 'World Challenge Deca Iron Triathlon' with 10 Ironman triathlons within 10 days. Before and after each Ironman, body mass, ECW, urinary [Na(+)], urinary [K(+)], urinary specific gravity, urinary osmolality and aldosterone and vasopressin in plasma were measured. The 11 finishers completed the total distance of 38 km swimming, 1800 km cycling and 422 km running within 145.5 (18.8) hours and 25 (22) minutes. ECW increased by 0.9 (1.1) L from 14.6 (1.5) L prerace to 15.5 (1.9) L postrace (P triathlon, but vasopressin did not. The increase in ECW and the increase in aldosterone were not associated.

  11. Simultaneous and accurate determination of water- and fat-soluble vitamins in multivitamin tablets by using an RP-HPLC method

    OpenAIRE

    2013-01-01

    In the present study, a reversed-phase high-performance liquid chromatographic (RP-HPLC) procedure was developed and validated for the simultaneous determination of seven water-soluble vitamins (thiamine, riboflavin, niacin, cyanocobalamin, ascorbic acid, folic acid, and p-aminobenzoic acid) and four fat-soluble vitamins (retinol acetate, cholecalciferol, α-tocopherol, and phytonadione) in multivitamin tablets. The linearity of the method was excellent (R² > 0.999) over the concentration...

  12. Optimum structural properties for an anode current collector used in a polymer electrolyte membrane water electrolyzer operated at the boiling point of water

    Science.gov (United States)

    Li, Hua; Fujigaya, Tsuyohiko; Nakajima, Hironori; Inada, Akiko; Ito, Kohei

    2016-11-01

    This study attempts to optimize the properties of the anode current collector of a polymer electrolyte membrane water electrolyzer at high temperatures, particularly at the boiling point of water. Different titanium meshes (4 commercial ones and 4 modified ones) with various properties are experimentally examined by operating a cell with each mesh under different conditions. The average pore diameter, thickness, and contact angle of the anode current collector are controlled in the ranges of 10-35 μm, 0.2-0.3 mm, and 0-120°, respectively. These results showed that increasing the temperature from the conventional temperature of 80 °C to the boiling point could reduce both the open circuit voltage and the overvoltages to a large extent without notable dehydration of the membrane. These results also showed that decreasing the contact angle and the thickness suppresses the electrolysis overvoltage largely by decreasing the concentration overvoltage. The effect of the average pore diameter was not evident until the temperature reached the boiling point. Using operating conditions of 100 °C and 2 A/cm2, the electrolysis voltage is minimized to 1.69 V with a hydrophilic titanium mesh with an average pore diameter of 21 μm and a thickness of 0.2 mm.

  13. Analysis of isotope element by electrolytic enrichment method for ground water and surface water in Saurashtra region, Gujarat, India

    Directory of Open Access Journals (Sweden)

    Sajal Singh

    2016-12-01

    Full Text Available The present study has been aimed for the assessment of isotope element Tritium (3H. It is a great threat to human health and environment for lengthy duration. The tritium exists in earth in diverse forms such as (1 small amounts of natural tritium are produced by alpha decay of lithium-7, (2 natural atmospheric tritium is also generated by secondary neutron cosmic ray bombardment of nitrogen, (3 atmospheric nuclear bomb testing in the 1950s, although the contribution from nuclear power plants is small. Tritium or 3H is a radioactive isotope of hydrogen with a half-life of 12.32 ± 0.02 years. Water samples from ground water, surface water, and precipitation were collected from different locations in Gujarat area and were analyzed for the same. Distillation of samples was done to reduce the conductivity. Deuterium and Hydrogen were removed by the process of physico-chemical fractionation in the tritium enrichment unit. The basis of physico-chemical fractionation is the difference in the strength of bonds formed by the light vs. the heavier isotope of a given element. A total of 10 cycles (runs were executed using Quintals process. Tritium concentration files were created with help of WinQ and Quick start software in Quintals process (Liquid Scintillation Spectrometer. The concentration of tritium in terms of tritium units (TU of various samples has been determined. The TU values of the samples vary in the range of 0.90–6.62 TU.

  14. Vitamin A

    Science.gov (United States)

    Vitamins are substances that your body needs to grow and develop normally. Vitamin A plays a role in your Vision Bone growth Reproduction Cell functions Immune system Vitamin A is an antioxidant. It can come from ...

  15. Vitamin E

    Science.gov (United States)

    Vitamins are substances that your body needs to grow and develop normally. Vitamin E is an antioxidant. It plays a role ... immune system and metabolic processes. Good sources of vitamin E include Vegetable oils Margarine Nuts and seeds ...

  16. Vitamin K

    Science.gov (United States)

    Vitamins are substances that your body needs to grow and develop normally. Vitamin K helps your body by making proteins for ... blood clotting. If you don't have enough vitamin K, you may bleed too much. Newborns have ...

  17. X-ray and Electrochemical Impedance Spectroscopy Diagnostic Investigations of Liquid Water in Polymer Electrolyte Membrane Fuel Cell Gas Diffusion Layers

    Science.gov (United States)

    Antonacci, Patrick

    In this thesis, electrochemical impedance spectroscopy (EIS) and synchrotron x-ray radiography were utilized to characterize the impact of liquid water distributions in polymer electrolyte membrane fuel cell (PEMFC) gas diffusion layers (GDLs) on fuel cell performance. These diagnostic techniques were used to quantify the effects of liquid water visualized on equivalent resistances measured through EIS. The effects of varying the thickness of the microporous layer (MPL) of GDLs were studied using these diagnostic techniques. In a first study on the feasibility of this methodology, two fuel cell cases with a 100 microm-thick and a 150 microm-thick MPL were compared under constant current density operation. In a second study with 10, 30, 50, and 100 microm-thick MPLs, the liquid water in the cathode substrate was demonstrated to affect mass transport resistance, while the liquid water content in the anode (from back diffusion) affected membrane hydration, evidenced through ohmic resistance measurements.

  18. First Principles Modeling of Structure and Transport in Solid Polymer Electrolytes, Ionic Liquids, and Methanol/Water Mixtures

    Science.gov (United States)

    2016-02-10

    1997. [3] Y.G.A. Graham, S. MacGlashan, Peter G. Bruce, Structure of the polymer electrolyte poly( ethylene oxide)6:LiAsF6, Nature 398, 792-794 (1999... chlorine , green; aluminum, pink; magnesium, yellow. 11    Table 1 Ab initio vibrational frequencies for EMImAlCl4 and EMImAl2Cl7

  19. Relationship between anode material, supporting electrolyte and current density during electrochemical degradation of organic compounds in water

    Energy Technology Data Exchange (ETDEWEB)

    Guzmán-Duque, Fernando L. [Grupo de diagnóstico y control de la contaminación, Facultad de ingeniería, Universidad de Antioquia, A.A. 1226, Medellín (Colombia); Palma-Goyes, Ricardo E. [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquía Udea, A.A. 1226, Medellín (Colombia); González, Ignacio [Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Química, Av. San Rafael Atlixco No 186, C.P 09340, México D.F (Mexico); Peñuela, Gustavo [Grupo de diagnóstico y control de la contaminación, Facultad de ingeniería, Universidad de Antioquia, A.A. 1226, Medellín (Colombia); Torres-Palma, Ricardo A., E-mail: rtorres@matematicas.udea.edu.co [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquía Udea, A.A. 1226, Medellín (Colombia)

    2014-08-15

    Highlights: • Pathway and efficiency are linked to the current-electrode–electrolyte interaction. • Unlike BDD, IrO{sub 2} route was independent of current but dependent on the electrolyte. • IrO{sub 2}/SO{sub 4}{sup 2−} and IrO{sub 2}/Cl{sup −} routes were via IrO{sub 3} and chlorine species, respectively. • BDD/SO{sub 4}{sup 2−} and IrO{sub 2}/Cl{sup −} systems were favored at low and high currents, respectively. - Abstract: Taking crystal violet (CV) dye as pollutant model, the electrode, electrolyte and current density (i) relationship for electro-degrading organic molecules is discussed. Boron-doped diamond (BDD) or Iridium dioxide (IrO{sub 2}) used as anode materials were tested with Na{sub 2}SO{sub 4} or NaCl as electrolytes. CV degradation and generated oxidants showed that degradation pathways and efficiency are strongly linked to the current density-electrode–electrolyte interaction. With BDD, the degradation pathway depends on i: If i < the limiting current density (i{sub lim}), CV is mainly degraded by ·OH radicals, whereas if i > i{sub lim}, generated oxidants play a major role in the CV elimination. When IrO{sub 2} was used, CV removal was not dependent on i, but on the electrolyte. Pollutant degradation in Na{sub 2}SO{sub 4} on IrO{sub 2} seems to occur via IrO{sub 3}; however, in the presence of NaCl, degradation was dependent on the chlorinated oxidative species generated. In terms of efficiency, the Na{sub 2}SO{sub 4} electrolyte showed better results than NaCl when BDD anodes were employed. On the contrary, NaCl was superior when combined with IrO{sub 2}. Thus, the IrO{sub 2}/Cl{sup −} and BDD/SO{sub 4}{sup 2−} systems were better at removing the pollutant, being the former the most effective. On the other hand, pollutant degradation with the BDD/SO{sub 4}{sup 2−} and IrO{sub 2}/Cl{sup −} systems is favored at low and high current densities, respectively.

  20. Relationship between anode material, supporting electrolyte and current density during electrochemical degradation of organic compounds in water.

    Science.gov (United States)

    Guzmán-Duque, Fernando L; Palma-Goyes, Ricardo E; González, Ignacio; Peñuela, Gustavo; Torres-Palma, Ricardo A

    2014-08-15

    Taking crystal violet (CV) dye as pollutant model, the electrode, electrolyte and current density (i) relationship for electro-degrading organic molecules is discussed. Boron-doped diamond (BDD) or Iridium dioxide (IrO2) used as anode materials were tested with Na2SO4 or NaCl as electrolytes. CV degradation and generated oxidants showed that degradation pathways and efficiency are strongly linked to the current density-electrode-electrolyte interaction. With BDD, the degradation pathway depends on i: If idegraded by OH radicals, whereas if i>i(lim), generated oxidants play a major role in the CV elimination. When IrO2 was used, CV removal was not dependent on i, but on the electrolyte. Pollutant degradation in Na2SO4 on IrO2 seems to occur via IrO3; however, in the presence of NaCl, degradation was dependent on the chlorinated oxidative species generated. In terms of efficiency, the Na2SO4 electrolyte showed better results than NaCl when BDD anodes were employed. On the contrary, NaCl was superior when combined with IrO2. Thus, the IrO2/Cl(-) and BDD/SO4(2-) systems were better at removing the pollutant, being the former the most effective. On the other hand, pollutant degradation with the BDD/SO4(2-) and IrO2/Cl(-) systems is favored at low and high current densities, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Stability of vitamins during extrusion.

    Science.gov (United States)

    Riaz, Mian N; Asif, Muhammad; Ali, Rashida

    2009-04-01

    Vitamins (fat and water soluble) are vital food ingredients for healthy living, required by our bodies for normal metabolism. These are present in most natural food in small quantities, but when we process food through thermal processing methods (especially extrusion) a reasonable amount of the present vitamins are lost. During extrusion, factors like barrel temperature, screw rpm, moisture of ingredients, die diameter, and throughput affect the retention of vitamins in food and feed. The vitamins most sensitive to the extrusion process are vitamin A and vitamin E from fat-soluble vitamins, and vitamin C, B(1), and folic acid from water-soluble vitamins. The other vitamins of the B group, such as B(2), B(6), B(12), niacin, Ca-pantothenate, and biotin, are stable. Vitamin E itself or in its complex form is quite unstable during processing and even in storage of extruded food. Ascorbic acid directly added or coated with fat and then added to feed during extrusion is also very unstable. Vitamins A, C, D, and E are also sensitive to oxidation, so these vitamins have minimum retention during storage of extruded food.

  2. Hydrogen production by water electrolysis by using ionic liquids as electrolytes; Producao de hidrogenio por eletrolise da agua usando liquidos ionicos como eletrolitos

    Energy Technology Data Exchange (ETDEWEB)

    Padilha, Janine Carvalho; Souza, Roberto Fernando de; Goncalves, Reinaldo Simoes [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica; Rault-Berthelot, Joelle [Universite de Rennes, Rennes (France). Inst. de Chimie. Lab. de Eletroquimica Molecular e Macromolecular

    2006-07-01

    Imidazolium ionic liquids (ILs) such as BMI.BF{sub 4} and BMI.PF{sub 6} were studied by cyclic voltammetry (CV). BMI.BF{sub 4} was used as an electrolyte for hydrogen production through water electrolysis. The system using these ionic liquids in a conventional electrochemical cell with platinum electrodes at room temperature and atmospheric pressure gives current densities (j) higher than 20 m A.cm{sup -2} and efficiencies of more than 94.5%. The catalytic activity of the electrode surface was not affected during the electrolyses mainly due to the chemical stability of the IL. (author)

  3. Ion-pair cloud-point extraction: a new method for the determination of water-soluble vitamins in plasma and urine.

    Science.gov (United States)

    Heydari, Rouhollah; Elyasi, Najmeh S

    2014-10-01

    A novel, simple, and effective ion-pair cloud-point extraction coupled with a gradient high-performance liquid chromatography method was developed for determination of thiamine (vitamin B1 ), niacinamide (vitamin B3 ), pyridoxine (vitamin B6 ), and riboflavin (vitamin B2 ) in plasma and urine samples. The extraction and separation of vitamins were achieved based on an ion-pair formation approach between these ionizable analytes and 1-heptanesulfonic acid sodium salt as an ion-pairing agent. Influential variables on the ion-pair cloud-point extraction efficiency, such as the ion-pairing agent concentration, ionic strength, pH, volume of Triton X-100, extraction temperature, and incubation time have been fully evaluated and optimized. Water-soluble vitamins were successfully extracted by 1-heptanesulfonic acid sodium salt (0.2% w/v) as ion-pairing agent with Triton X-100 (4% w/v) as surfactant phase at 50°C for 10 min. The calibration curves showed good linearity (r(2) > 0.9916) and precision in the concentration ranges of 1-50 μg/mL for thiamine and niacinamide, 5-100 μg/mL for pyridoxine, and 0.5-20 μg/mL for riboflavin. The recoveries were in the range of 78.0-88.0% with relative standard deviations ranging from 6.2 to 8.2%.

  4. Development of open-air type electrolyte-as-cathode glow discharge-atomic emission spectrometry for determination of trace metals in water

    Science.gov (United States)

    Kim, Hyo J.; Lee, Jeong H.; Kim, Myung Y.; Cserfalvi, T.; Mezei, P.

    2000-07-01

    The open-air type electrolyte cathode atomic glow discharge (ELCAD) has been developed and studied for fundamental and analytical applications for determination of trace heavy metals in water. The normal closed-type discharge cell shows some problems such as unstable plasma due to changes in the pressure inside the cell during the discharge, and water vapor condensing onto the window. Applying approximately 1500 V to the several-millimeter gap between the electrolyte solution cathode and a Pt rod anode in atmospheric air pressure produced a stable plasma and significantly improved sensitivity. The emission spectrum of de-ionized water containing 100 mg/l Cu was measured and some emission lines were found from Cu I (324.7 nm, 327.4 nm and 510.5 nm) and Cu II (224.7 nm and 229.4 nm). The LODs of Cr, Cu, Fe, Mn, Ni, Pb, and Zn are in the ranges from 0.01 mg/l to 0.6 mg/l. The LODs of Cu, Mn, Pb and Zn improve by approximately one order of magnitude compared to the previous closed-type ELCAD.

  5. HPLC测定小儿复方四维亚铁散中的水溶性维生素%Determination of water-soluble vitamins in Pediatric compound of four vitamins and Ferrous fumarate powder by RP- HPLC

    Institute of Scientific and Technical Information of China (English)

    蒋秋桃; 梁晟

    2012-01-01

    目的 采用RP- HPLC法测定小儿复方四维亚铁散中Vit B1、Vit B6和烟酸的含量.方法 采用C18色谱柱,流动相为5 μmol·L -己烷磺酸钠溶液-甲醇(80:20),检测波长为280 nm.结果 Vit B1、Vit B6和烟酸分离良好,三者的进样量分别为0.0562 ~0.9000 μg、0.0613~0.9808 μ.g、0.7550 ~ 12.0800 μg时,与峰面积均呈良好的线性关系;其平均回收率分别为100.15%、99.85%、99.64%.结论 所用方法准确简便、重复性好、回收率高,可用于小儿四维亚铁散中水溶性维生素的测定.%OBJECTIVE To develop a method for the determination of Vit B, ,Vit B6 and nicotinic acid in Pediatric compound of four vitamins and ferrous fumarate powder. METHODS Ionpair reversed - phase ( RP) high performance liquid ehromatography (HPLC) was performed using a C18 column with 0. 005 mol·L‐1 of sodium hexane sulfonate - methanol (80 : 20) as mobile phase. The detection wavelength was set at 280 nm. RESULTS Vitamin B, ,B6 and nicotinic acid were separated well. The good linearity was obtained over the range of 0. 0562 - 0. 9000 μg for Vitamin B, , of 0. 0613 - 0. 9808 |xg for Vitamin B6 , of 0. 7550 - 12. 0800 μg for nicotinic acid. The recovery of Vitamin B1 , Vitamin B6 and nicotinic acid was 100. 15% ,99. 85% and 99. 64% .respectively. CONCLUSION This method is well repeatable, accurate, and simple with high recovery. It can be used for the determination of water - soluble vitamins in Pediatric compound of four vitamins and ferrous fumarate powder.

  6. Vitamin Chart

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Vitamin Chart KidsHealth > For Teens > Vitamin Chart Print A A A en español Tabla de las vitaminas Type Benefits Sources Quantity Vitamin A Vitamin A prevents eye problems, promotes a ...

  7. Vitamin Chart

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Vitamin Chart KidsHealth > For Teens > Vitamin Chart A A A en español Tabla de las vitaminas Type Benefits Sources Quantity Vitamin A Vitamin A prevents eye problems, promotes a ...

  8. Comparison of coconut water and a carbohydrate-electrolyte sport drink on measures of hydration and physical performance in exercise-trained men

    Directory of Open Access Journals (Sweden)

    Kalman Douglas S

    2012-01-01

    Full Text Available Abstract Background Sport drinks are ubiquitous within the recreational and competitive fitness and sporting world. Most are manufactured and artificially flavored carbohydrate-electrolyte beverages. Recently, attention has been given to coconut water, a natural alternative to manufactured sport drinks, with initial evidence indicating efficacy with regard to maintaining hydration. We compared coconut water and a carbohydrate-electrolyte sport drink on measures of hydration and physical performance in exercise-trained men. Methods Following a 60-minute bout of dehydrating treadmill exercise, 12 exercise-trained men (26.6 ± 5.7 yrs received bottled water (BW, pure coconut water (VitaCoco®: CW, coconut water from concentrate (CWC, or a carbohydrate-electrolyte sport drink (SD [a fluid amount based on body mass loss during the dehydrating exercise] on four occasions (separated by at least 5 days in a random order, single blind (subject and not investigators, cross-over design. Hydration status (body mass, fluid retention, plasma osmolality, urine specific gravity and performance (treadmill time to exhaustion; assessed after rehydration were determined during the recovery period. Subjective measures of thirst, bloatedness, refreshed, stomach upset, and tiredness were also determined using a 5-point visual analog scale. Results Subjects lost approximately 1.7 kg (~2% of body mass during the dehydrating exercise and regained this amount in a relatively similar manner following consumption of all conditions. No differences were noted between coconut water (CW or CWC and SD for any measures of fluid retention (p > 0.05. Regarding exercise performance, no significant difference (p > 0.05 was noted between BW (11.9 ± 5.9 min, CW (12.3 ± 5.8 min, CWC (11.9 ± 6.0 min, and SD (12.8 ± 4.9 min. In general, subjects reported feeling more bloated and experienced greater stomach upset with the CW and CWC conditions. Conclusion All tested beverages are

  9. Development of an Ion-Pairing Reagent and HPLC-UV Method for the Detection and Quantification of Six Water-Soluble Vitamins in Animal Feed

    Directory of Open Access Journals (Sweden)

    Ho Jin Kim

    2016-01-01

    Full Text Available A novel and simple method for detecting six water-soluble vitamins in animal feed using high performance liquid chromatography equipped with a photodiode array detector (HPLC/PDA and ion-pairing reagent was developed. The chromatographic peaks of the six water-soluble vitamins were successfully identified by comparing their retention times and UV spectra with reference standards. The mobile phase was composed of buffers A (5 mM PICB-6 in 0.1% CH3COOH and B (5 mM PICB-6 in 65% methanol. All peaks were detected using a wavelength of 270 nm. Method validation was performed in terms of linearity, sensitivity, selectivity, accuracy, and precision. The limits of detection (LODs for the instrument employed in these experiments ranged from 25 to 197 μg/kg, and the limits of quantification (LOQs ranged from 84 to 658 μg/kg. Average recoveries of the six water-soluble vitamins ranged from 82.3% to 98.9%. Method replication resulted in intraday and interday peak area variation of <5.6%. The developed method was specific and reliable and is therefore suitable for the routine analysis of water-soluble vitamins in animal feed.

  10. A water soluble vitamin B12-ReI fluorescent conjugate for cell uptake screens: use in the confirmation of cubilin in the lung cancer line A549.

    Science.gov (United States)

    Vortherms, Anthony R; Kahkoska, Anna R; Rabideau, Amy E; Zubieta, Jon; Andersen, Louise Lund; Madsen, Mette; Doyle, Robert P

    2011-09-21

    A water soluble vitamin B(12)-rhenium conjugate was synthesized and used in concert with intrinsic factor to screen for cubilin receptor-mediated uptake in lung cancer cells. Internalization of the conjugate demonstrated that it could be used to rapidly screen for the cubilin receptor in living cells, subsequently confirmed with Western blotting and RT-PCR.

  11. Electrolytic fixer.

    Science.gov (United States)

    Stevens

    1982-12-01

    Interest in the recovery of silver from radiographic film generates a need to understand the operating procedures of recovery units utilizing the electrolytic fixer principle. Tailing or terminal units and recirculation units using electrolysis are evaluated. Difficulties encountered in the number of Coulombs applied to a specific amount of fixer are discussed. Reduction of sulfiding as a result of electrolysis and variations in film volumes are noted. The quantity and quality of silver collected can be improved by being aware of alterations in chemical activity used in a silver recovery program.

  12. Degradation of Remazol Red in batik dye waste water by contact glow discharge electrolysis method using NaOH and NaCl electrolytes

    Science.gov (United States)

    Saksono, Nelson; Putri, Dita Amelia; Suminar, Dian Ratna

    2017-03-01

    Contact Glow Discharge Electrolysis (CGDE) method is one of Plasma Electrolysis technology which has been approved to degrade organic waste water because it is very productive in producing hydroxyl radical. This study aims to degrade Remazol Red by CGDE method and evaluate important parameters that have influent in degradation process of Remazol Red in Batik dye waste water in batch system. The kind of electrolyte (acid and base) and the addition of metal ion such as Fe2+ have affected Remazol Red degradation percentage. Ultraviolet-Visible (UV-Vis) absorption spectra were used to monitor the degradation process. The result of study showed that percentage degradation was 99.97% which obtained by using NaCl 0.02 M with addition Fe2+ 20 ppm, applied voltage 700 volt, anode depth 0.5 cm, initial concentration of Remazol Red 250 ppm and the temperature of solutions was maintained 50-60 ˚C.

  13. Measurement of extremely (2) H-enriched water samples by laser spectrometry: application to batch electrolytic concentration of environmental tritium samples.

    Science.gov (United States)

    Wassenaar, L I; Kumar, B; Douence, C; Belachew, D L; Aggarwal, P K

    2016-02-15

    Natural water samples artificially or experimentally enriched in deuterium ((2) H) at concentrations up to 10,000 ppm are required for various medical, environmental and hydrological tracer applications, but are difficult to measure using conventional stable isotope ratio mass spectrometry. Here we demonstrate that off-axis integrated cavity output (OA-ICOS) laser spectrometry, along with (2) H-enriched laboratory calibration standards and appropriate analysis templates, allows for low-cost, fast, and accurate determinations of water samples having δ(2) HVSMOW-SLAP values up to at least 57,000 ‰ (~9000 ppm) at a processing rate of 60 samples per day. As one practical application, extremely (2) H-enriched samples were measured by laser spectrometry and compared to the traditional (3) H Spike-Proxy method in order to determine tritium enrichment factors in the batch electrolysis of environmental waters. Highly (2) H-enriched samples were taken from different sets of electrolytically concentrated standards and low-level (tritium samples, and all cases returned accurate and precise initial low-level (3) H results. The ability to quickly and accurately measure extremely (2) H-enriched waters by laser spectrometry will facilitate the use of deuterium as a tracer in numerous environmental and other applications. For low-level tritium operations, this new analytical ability facilitated a 10-20 % increase in sample productivity through the elimination of spike standards and gravimetrics, and provides immediate feedback on electrolytic enrichment cell performance. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Polyethylene glycol-electrolyte solution (PEG-ES)

    Science.gov (United States)

    Polyethylene glycol-electrolyte solution (PEG-ES) is used to empty the colon (large intestine, bowel) before a colonoscopy ( ... Polyethylene glycol-electrolyte solution (PEG-ES) comes as a powder to mix with water and take by mouth. ...

  15. A Novel HPLC Method for the Concurrent Analysis and Quantitation of Seven Water-Soluble Vitamins in Biological Fluids (Plasma and Urine: A Validation Study and Application

    Directory of Open Access Journals (Sweden)

    Margherita Grotzkyj Giorgi

    2012-01-01

    Full Text Available An HPLC method was developed and validated for the concurrent detection and quantitation of seven water-soluble vitamins (C, B1, B2, B5, B6, B9, B12 in biological matrices (plasma and urine. Separation was achieved at 30°C on a reversed-phase C18-A column using combined isocratic and linear gradient elution with a mobile phase consisting of 0.01% TFA aqueous and 100% methanol. Total run time was 35 minutes. Detection was performed with diode array set at 280 nm. Each vitamin was quantitatively determined at its maximum wavelength. Spectral comparison was used for peak identification in real samples (24 plasma and urine samples from abstinent alcohol-dependent males. Interday and intraday precision were <4% and <7%, respectively, for all vitamins. Recovery percentages ranged from 93% to 100%.

  16. 非线性光学研究水及电解质水溶液界面——空气/电解质水溶液界面特定阴阳离子效应%Nonlinear Optical Spectroscopy Studies on Water and Aqueous Solution Interfaces Specific Ion Effect Electrolyte Aqueous Solution Interfaces Electrolyte at Air/Electrolyte Aqueous Solution Interfaces

    Institute of Scientific and Technical Information of China (English)

    邓罡华; 王鸿飞; 郭源

    2012-01-01

    Water and electrolyte aqueous solution interfaces play crucial roles in many processes of physics, chemistry, environment, and biology. People have attempted to understand the structure and dynamics of water and electrolyte aqueous solution interfaces for decades. Recently, both experimental and theoretical studies have proved that larger and more polarizable anions attend to accumulate at the interface and affect the interfaeial water hydrogen bonding structure. In this review, we present recent progress of nonlinear optical spectroscopy studies on water and electrolyte aqueous solution interfaces with nonresonant second harmonic generation (SHG) and sum frequency generation vibrational spectroscopy (SFG-VS). First, we addressed the signal source of the nonresonant second harmonic generation of the air/water interface. Analysis of the experimental results showed that the SHG signal of the air/water interface can be treated fully only with dipolar contribution, which lay the foundation of nonresonant second harmonic generation in studying water and electrolyte aqueous solution interfaces. We then utilized the polarization and molecular symmetry analyses to assign the SFG-VS spectra peaks to different interfacial species at the air/water interface. These results provide detailed informations on the orientation, structure, and dynamics of water molecules at the air/water interface. Subsequently, we studied several kinds of electrolyte aqueous solution interfaces by nonresonant SHG and SFG-VS. These results showed that not only the larger and more polarizable Branion, but also the smaller and less polarizable Cl-, F- anions are enriched at the air/water interface and increased the interfacial thickness. Furthermore, we also observed the specific Na^+, K^+ cation effect on the interfacial thickness and interfacial water hydrogen bonging structure.%水及电解质溶液界面在物理、化学、环境及生物等各种过程中扮演着至关重要的角色。百年

  17. Modeling and High-Resolution-Imaging Studies of Water-Content Profiles in a Polymer-Electrolyte-Fuel-Cell Membrane-Electrode Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, Cynthia; Weber, A.Z.; Hickner, M.A.

    2008-03-06

    Water-content profiles across the membrane electrode assembly of a polymer-electrolyte fuel cell were measured using high-resolution neutron imaging and compared to mathematical-modeling predictions. It was found that the membrane held considerably more water than the other membrane-electrode constituents (catalyst layers, microporous layers, and macroporous gas-diffusion layers) at low temperatures, 40 and 60 C. The water content in the membrane and the assembly decreased drastically at 80 C where vapor transport and a heat-pipe effect began to dominate the water removal from the membrane-electrode assembly. In the regimes where vapor transport was significant, the through-plane water-content profile skewed towards the cathode. Similar trends were observed as the relative humidity of the inlet gases was lowered. This combined experimental and modeling approach has been beneficial in rationalizing the results of each and given insight into future directions for new experimental work and refinements to currently available models.

  18. Extraction of Carbon Dioxide and Hydrogen from Seawater By an Electrolytic Cation Exchange Module (E-CEM) Part V: E-CEM Effluent Discharge Composition as aFunction of Electrode Water Composition

    Science.gov (United States)

    2017-08-01

    Cation Exchange Module (E-CEM) Part V: E-CEM Effluent Discharge Composition as a Function of Electrode Water Composition August 1, 2017 Approved for...Electrolytic Cation Exchange Module (E-CEM) Part V: E-CEM Effluent Discharge Composition as a Function of Electrode Water Composition Heather D. Willauer...regulate E-CEM effluent discharge water composition with respect to pH and chlorine content. This report details the results of two separate

  19. Vitamin D

    Science.gov (United States)

    ... body needs to grow and develop normally. Vitamin D helps your body absorb calcium. Calcium is one ... building blocks of bone. A lack of vitamin D can lead to bone diseases such as osteoporosis ...

  20. Vitamin K

    Science.gov (United States)

    ... Dietary Reference Intakes: Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron Manganese, Molybdenium, Nickel, Silicon, ... provided herein should not be used during any medical emergency or for the diagnosis or treatment of ...

  1. Vitamin C

    Science.gov (United States)

    ... body needs to grow and develop normally. Vitamin C is an antioxidant. It is important for your ... healing and helps the body absorb iron. Vitamin C comes from fruits and vegetables. Good sources include ...

  2. Vitamin D

    Science.gov (United States)

    ... thin, and brittle bones, a condition known as rickets in children and osteomalacia in adults. Vitamin D ... the body. In children, vitamin D deficiency causes rickets, where the bones become soft and bend. It's ...

  3. Vitamin E

    Science.gov (United States)

    ... vitamin E combined with other antioxidants, zinc, and copper showed promise for slowing down the rate of ... several years had an increased risk of prostate cancer. Are there any interactions with vitamin E that ...

  4. Investigation Of Hydrogen Production By Using Composite Membrane (Nafion/Zro2-Based Solid Polymer Electrolyte Water Electrolyser

    Directory of Open Access Journals (Sweden)

    E.L.Santhi priyaa ,

    2015-05-01

    Full Text Available In the present study, Composite materials based on perfluorinated cation-exchange membrane incorporating particles of Zirconium and Nafion is synthesized .With this membrane the performance of the electrolysis cell improved considerably at room temperature and atmospheric pressure. In addition, by using catalysts and membranes, the performance of this Composite membrane is studied by varying voltage range with respect to hydrogen yield and at current density 0.1, 0.2, 0.3, 0.4, and 0.5(A cm-2 , With a Nafion 115 membrane as a reference electrolyte. Experiments have shown that 99.9% purity of hydrogen Gas is evolved The physicochemical properties of the composite membranes such as thermogravimetric analyzer (TGA, Scanning Electron Microscope (SEM, XRD (X-ray powder diffraction, Fourier transform infrared spectroscopyand and Ion Exchange Capacity is determined. The fabricated composite membranes have shown the significant improvement of all tested properties compared to that of pure Nafion membrane.

  5. Engineering design and testing of a ground water remediation system using electrolytically generated hydrogen with a palladium catalyst for dehalogenation of chlorinated hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, R.

    1997-12-01

    Recent studies have shown that dissolved hydrogen causes rapid dehalogenation of chlorinated hydrocarbons in the presence of a palladium catalyst. The speed and completeness of these reactions offer advantages in designing remediation technologies for certain ground water contamination problems. However, a practical design challenge arises in the need to saturate the aqueous phase with hydrogen in an expeditious manner. To address this issue, a two-stage treatment reactor has been developed. The first stage consists of an electrolytic cell that generates hydrogen by applying a voltage potential across the influent water stream. The second stage consists of a catalyst column of palladium metal supported on alumina beads. A bench-scale reactor has been used to test this design for treating ground water contaminated with trichloroethene and other chlorinated hydrocarbons. In influent streams containing contaminant concentrations up to 4 ppm, initial results confirm that destruction efficiencies greater than 95% may be achieved with residence times short enough to allow practical implementation in specially designed flow-through treatment wells. Results from the bench-scale tests are being used to design a pilot ground water treatment system.

  6. Engineering design and testing of a ground water remediation system using electrolytically generated hydrogen with a palladium catalyst for dehalogenation of chlorinated hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, R.

    1997-12-01

    Recent studies have shown that dissolved hydrogen causes rapid dehalogenation of chlorinated hydrocarbons in the presence of a palladium catalyst. The speed and completeness of these reactions offer advantages in designing remediation technologies for certain ground water contamination problems. However, a practical design challenge arises in the need to saturate the aqueous phase with hydrogen in an expeditious manner. To address this issue, a two-stage treatment reactor has been developed. The first stage consists of an electrolytic cell that generates hydrogen by applying a voltage potential across the influent water stream. The second stage consists of a catalyst column of palladium metal supported on alumina beads. A bench-scale reactor has been used to test this design for treating ground water contaminated with trichloroethene and other chlorinated hydrocarbons. In influent streams containing contaminant concentrations up to 4 ppm, initial results confirm that destruction efficiencies greater than 95% may be achieved with residence times short enough to allow practical implementation in specially designed flow-through treatment wells. Results from the bench-scale tests are being used to design a pilot ground water treatment system.

  7. Terahertz characteristics of electrolytes in aqueous Luria-Bertani media

    Science.gov (United States)

    Oh, Seung Jae; Son, Joo-Hiuk; Yoo, Ocki; Lee, Dong-Hee

    2007-10-01

    We measured the optical constants of aqueous biomaterial mixtures with various electrolyte concentrations using terahertz time-domain spectroscopy. The mixtures were divided into water and other electrolyte parts in mass fractions for analysis. The optical constants of the electrolyte, excluding water, were obtained by applying the ideal mixture equation, and the power absorption of the electrolyte was observed to be larger than that of water above 1THz. Data from the measurement were fitted with the modified double Debye model, and the reorientation and hydrogen-bond formation decomposition times were found to decrease as the electrolyte concentration increased.

  8. Complexity of vitamin E metabolism

    Institute of Scientific and Technical Information of China (English)

    Lisa Schm?lz; Marc Birringer; Stefan Lorkowski; Maria Wallert

    2016-01-01

    Bioavailability of vitamin E is influenced by several factors, most are highlighted in this review. While gender, age and genetic constitution influence vitamin E bioavailability but cannot be modified, life-style and intake of vitamin E can be. Numerous factors must be taken into account however, i.e., when vitamin E is orally administrated, the food matrix may contain competing nutrients. The complex metabolic processes comprise intestinal absorption, vascular transport, hepatic sorting by intracellular binding proteins, such as the significant α-tocopherol-transfer protein, and hepatic metabolism. The coordinated changes involved in the hepatic metabolism of vitamin E provide an effective physiological pathway to protect tissues against the excessive accumulation of, in particular, non-α-tocopherol forms. Metabolism of vitamin E begins with one cycle of CYP4F2/CYP3A4-dependent ω-hydroxylation followed by five cycles of subsequent β-oxidation, and forms the water-soluble end-product carboxyethylhydroxychroman. All known hepatic metabolites can be conjugated and are excreted, depending on the length of their sidechain, either via urine or feces. The physiological handling of vitamin E underlies kinetics which vary between the different vitamin E forms. Here, saturation of the side-chain and also substitution of the chromanol ring system are important. Most of the metabolic reactions and processes that are involved with vitamin E are also shared by other fat soluble vitamins. Influencing interactions with other nutrients such as vitamin K or pharmaceuticals are also covered by this review. All these processes modulate the formation of vitamin E metabolites and their concentrations in tissues and body fluids. Differences in metabolism might be responsible for the discrepancies that have been observed in studies performed in vivo and in vitro using vitamin E as a supplement or nutrient. To evaluate individual vitamin E status, the analytical procedures used for

  9. On-ice sweat rate, voluntary fluid intake, and sodium balance during practice in male junior ice hockey players drinking water or a carbohydrate-electrolyte solution.

    Science.gov (United States)

    Palmer, Matthew S; Logan, Heather M; Spriet, Lawrence L

    2010-06-01

    This study evaluated the repeatability of hydration and sweat measurements taken during on-ice hockey practices with players drinking only water, and determined whether having only a carbohydrate-electrolyte solution (CES) to drink during practices decreased fluid intake or affected other hydration and (or) sweat measures. All testing was conducted on elite players of an Ontario Hockey League team (+/-SE; mean age, 17.6 +/- 0.3 years; mean height, 182.9 +/- 1.4 cm; mean body mass, 83.0 +/- 1.7 kg). Players were studied 3 times over the course of 6 weekly on-ice practices (+/-SE; mean playing time, 1.58 +/- 0.07 h; mean temperature, 11.4 +/- 0.8 degrees C; mean relative humidity, 52% +/- 3%). There was strong repeatability of the measured hydration and sweat parameters between 2 similar on-ice practices when players drank only water. Limiting the players to drinking only a CES (as opposed to water) did not decrease fluid intake during practice (+/-SE; mean CES intake, 0.72 +/- 0.07 L.h-1 vs. mean water intake, 0.82 +/- 0.08 L.h-1) or affect sweat rate (1.5 +/- 0.1 L.h-1 vs. 1.5 +/- 0.1 L.h-1), sweat sodium concentration (72.4 +/- 5.6 mmol.L-1 vs. 73.0 +/- 4.4 mmol.L-1), or percent body mass loss (1.1% +/- 0.2% vs. 0.9% +/- 0.2%). Drinking a CES also improved sodium balance (-2.1 +/- 0.2 g.h-1 vs. -2.6 +/- 0.3 g.h-1) and provided the players with a significant carbohydrate (43 +/- 4 g.h-1 vs. 0 +/- 0 g.h-1) during practice. In summary, a single field sweat test during similar on-ice hockey practices in male junior hockey players is sufficient to evaluate fluid and electrolyte balance. Also, a CES does not affect voluntary fluid intake during practice, compared with water, in these players. The CES provided some salt to offset the salt lost in sweat, and carbohydrate, which may help maintain physical and mental performance in the later stages of practice.

  10. Simultaneous determination of some water-soluble vitamins and preservatives in multivitamin syrup by validated stability-indicating high-performance liquid chromatography method.

    Science.gov (United States)

    Vidović, Stojanka; Stojanović, Biljana; Veljković, Jelena; Prazić-Arsić, Ljiljana; Roglić, Goran; Manojlović, Dragan

    2008-08-22

    HPLC stability-indicating method has been developed for the simultaneous determination of some water-soluble vitamins (ascorbic acid, thiamine hydrochloride, riboflavin-5'-phosphate sodium, pyridoxine hydrochloride, nicotinamide, D(+)-panthenol) and two preservatives (methylparaben and sodium benzoate) in multivitamin syrup preparation. Water-soluble vitamins, preservatives and their degradants were separated on Zorbax SB-Aq (C(18)) (250 mm x 4.6 mm, 5 microm) column at an ambient temperature. Combined isocratic and gradient elution was performed with a mobile phase consisting of 0.0125 M hexane-1-sulfonic acid sodium salt in 0.1% (m/v) o-phosphoric acid, pH 2.4-2.5 (solvent A) and acetonitrile (solvent B) at the flow-rate 1 ml min(-1). Starting with solvent A an isocratic elution was performed for 15 min, then the composition was changed to 85% of A and 15% of B during the next 20 min and it was constant for 5 min, then the composition was changed to 70% of A and 30% of B during next 15 min and it was constant for 5 min and finally was changed to 100% of A as at the beginning of the elution. Detection was performed with diode array detector at 210, 230 and 254 nm. Multivitamin syrup preparation was subjected to stress testing (forced degradation) in order to demonstrate that degradants from the vitamins, preservatives and/or product excipients do not interfere with the quantification of vitamins and preservatives. Typical validation characteristics: selectivity, accuracy, precision, linearity, range, limit of quantification and limit of detection were evaluated for vitamins and preservatives.

  11. COMBINED BIOLOGICAL-PHOTOCATALYTIC TREATMENT FOR THE MINERALIZATION OF A MIXTURE OF CHLOROPHENOLS IN AN ELECTROLYTE-CONTAINING MODEL WATER AND SPONTANEOUS SEDIMENTATION OF TITANIUM DIOXIDE

    Directory of Open Access Journals (Sweden)

    Dhanus Suryaman

    2010-06-01

    Full Text Available To shorten the biological treating time and to examine the effect of electrolytes in a model water on the photocatalytic treatment, the combined biological-photocatalytic treatment was evaluated for removal of a mixture (total: 100 mg L-1, each: 25 mg L-1 of 2-chlorophenol (2-CP, 2,4-dichlorophenol (2,4-DCP, 2,4,5-trichlorophenol (2,4,5-TCP, and pentachlorophenol (PCP in tap water. The mineralization of the four phenols was performed by a flow (biological treatment-circulative flow (photocatalytic treatment operation under black light and sunlight irradiations. After a large portion of biodegradable 2-CP and 2,4-DCP, and around half amount of slightly biodegradable 2,4,5-TCP were removed by the biological treatment, the remained three chlorophenols, biorecalcitrant PCP, and  biodegradation products were completely removed by the subsequent photocatalytic treatment. The combined treatment significantly shortened the degradation time only the biotreatment. High circulative flow rate (600 mL min-1 enabled for TiO2 particles to completely suspend in a tubular photoreactor and resulted in high removals of chlorophenols and TOC. Sunlight irradiation was successfully used and the saving of the electric energy of black light was possible. Since TiO2 particles in the tap water spontaneously sedimented on standing after the photocatalytic treatment, the combined system can be operated by integrating it with the TiO2 separation.   Keywords: photocatalysis, titanium dioxide, biodegradation, pollutant, wastewater

  12. Simultaneous water desalination and electricity generation in a microbial desalination cell with electrolyte recirculation for pH control

    KAUST Repository

    Qu, Youpeng

    2012-02-01

    A recirculation microbial desalination cell (rMDC) was designed and operated to allow recirculation of solutions between the anode and cathode chambers. This recirculation avoided pH imbalances that could inhibit bacterial metabolism. The maximum power density was 931±29mW/m 2 with a 50mM phosphate buffer solution (PBS) and 776±30mW/m 2 with 25mM PBS. These power densities were higher than those obtained without recirculation of 698±10mW/m 2 (50mM PBS) and 508±11mW/m 2 (25mM PBS). The salt solution (20g/L NaCl) was reduced in salinity by 34±1% (50mM) and 37±2% (25mM) with recirculation (rMDC), and by 39±1% (50mM) and 25±3% (25mM) without recirculation (MDC). These results show that electrolyte recirculation using an rMDC is an effective method to increase power and achieve efficient desalination by eliminating pH imbalances. © 2011 Elsevier Ltd.

  13. [Vitamin deficiencies and hypervitaminosis].

    Science.gov (United States)

    Mino, M

    1999-10-01

    There have recently been very few deficiencies with respect to fat soluble and water soluble vitamins in Japan All-trans-retinoic acid as induction or maintenance treatment improves disease free and overall survival against acute promyelocytic leukemia. In the isolated vitamin E deficiencies gene mutation has been cleared for alpha-tocopherol transferprotein. Recently, a relation of nutritional vitamin K intake and senile osteoporosis in women was epidemiologically demonstrated on a prospective study. Thiamin was yet noticed as development of deficiency in alcoholism, while the importance of supplemental folic acid during pregnancy has become especially clear in light of studies showing that folic acid supplements reduce the risk of neural tube defects in the fetus. With respect to hypervitaminosis, the Council for Responsible Nutrition (CRN), USA, has established safe intakes by identifying the NOAEL (No Observed Adverse Effect Level) and LOAEL (Lowest Observed Adverse Effect Level). Summaries of NOAEL and LOAEL for individual vitamins were shown.

  14. Effect of heat stress and drinking water salt supplements on plasma electrolytes and aldosterone concentration in broiler chickens

    Science.gov (United States)

    Deyhim, F.; Teeter, R. G.

    1995-12-01

    An experiment was conducted to evaluate the effects of supplementing drinking water with isomolar (0.067 mol/l) KCl or NaCl on mass gain, food and water consumption, rectal temperature, and plasma concentrations of aldosterone, Na+, and K+ in broiler chickens reared in thermoneutral and cycling heat stressing environments. Heat stress decreased ( P≤0.05) mass gain, food consumption, and plasma concentrations of Na+ and K+, while increases ( P≤0.05) in plasma concentrations of aldosterone, rectal temperature, and water consumption were observed. Drinking water supplemented with either KCl or NaCl increased ( P≤0.05) broiler mass gain and water consumption, but had no effect ( P>0.1) on the other variables evaluated. The results of this study indicate that broiler chickens in a heat stress environment are under osmotic stress and supplementing drinking water with 0.067 mol/1 KCl or NaCl does not lessen this stress.

  15. Effects of temperature on electrolyte balance and osmoregulation of the alewife (Alosa pseudoharengus) in fresh and sea water

    Science.gov (United States)

    Stanley, Jon G.; Colby, Peter J.

    1971-01-01

    A study of the effects of temperature and salinity on ionoregulation in the alewife, Alosa pseudoharengus, revealed that concentrations of sodium, potassium, and calcium in plasma and muscle were similar in fish adapted to fresh water and those adapted to sea water. The non-stressed alewife is apparently an excellent ionoregulator in both environments.

  16. Phosphoric acid-doped poly(1-vinyl-1,2,4-triazole) as water-free proton conducting polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Celik, Sevim Ue.; Aslan, Ayse; Bozkurt, Ayhan [Department of Chemistry, Fatih University, 34500 Bueyuekcekmece-Istanbul (Turkey)

    2008-08-15

    The development of anhydrous proton conducting membrane is important for the operation of polymer electrolyte membrane fuel cell (PEMFC) at intermediate temperature (100-200 C). In the present work, poly(1-vinyl-1,2,4-triazole), PVTri was produced by free radical polymerization of 1-vinyl-1,2,4-triazole with a high yield. The molecular weight of the homopolymer was measured via gel permeation chromatography (GPC) and M{sub w} was found to be 104,216 g/mol. The structure of the homopolymer was proved by solid state {sup 13}C CP-MAS NMR spectroscopy. The polymer was doped with phosphoric acid at various molar ratios x = 1 and x = 2. The proton transfer from H{sub 3}PO{sub 4} to the triazole rings was proved with Fourier-transform infrared spectroscopy (FT-IR). Thermogravimetry (TG) analysis showed that the samples are thermally stable up to approximately 250 C. Differential scanning calorimetry (DSC) results illustrated the homogeneity of the materials as well as the plasticizing effect of the dopant. The electrochemical stability of the materials was studied by cyclic voltammetry (CV). The proton conductivity of these materials increased with dopant concentration and the temperature. In the anhydrous state, the proton conductivity of PVTri 1 H{sub 3}PO{sub 4} is 5 x 10{sup -} {sup 3} S/cm at 150 C and the conductivity of PVTri 2 H{sub 3}PO{sub 4} was 4 x 10{sup -} {sup 3} S/cm at 140 C. (author)

  17. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... Resist the pressure to buy a product or treatment on the spot. Some supplement products may be expensive or may not provide the benefit you expect. For example, excessive amounts of water-soluble vitamins, like vitamins C and B, are ...

  18. Simultaneous and accurate determination of water- and fat-soluble vitamins in multivitamin tablets by using an RP-HPLC method

    Directory of Open Access Journals (Sweden)

    Semahat Kucukkolbasi

    2013-01-01

    Full Text Available In the present study, a reversed-phase high-performance liquid chromatographic (RP-HPLC procedure was developed and validated for the simultaneous determination of seven water-soluble vitamins (thiamine, riboflavin, niacin, cyanocobalamin, ascorbic acid, folic acid, and p-aminobenzoic acid and four fat-soluble vitamins (retinol acetate, cholecalciferol, α-tocopherol, and phytonadione in multivitamin tablets. The linearity of the method was excellent (R² > 0.999 over the concentration range of 10 - 500 ng mL-1. The statistical evaluation of the method was carried out by performing the intra- and inter-day precision. The accuracy of the method was tested by measuring the average recovery; values ranged between 87.4% and 98.5% and were acceptable quantitative results that corresponded with the label claims.

  19. Influence of methionine and vitamin E on fluoride concentration in bones and teeth of rats exposed to sodium fluoride in drinking water.

    Science.gov (United States)

    Błaszczyk, Iwona; Birkner, Ewa; Gutowska, Izabela; Romuk, Ewa; Chlubek, Dariusz

    2012-06-01

    Increased exposure to fluorine-containing compounds leads to accumulation of fluorides in hard tissues of bones and teeth, which may result in numerous skeletal and dental disorders. This study evaluates the influence of methionine and vitamin E on fluoride concentration in bones and teeth of rats subjected to long-term exposure to sodium fluoride in drinking water. The study was conducted in 30 3-month-old female Wistar FL rats. The animals were divided into five groups, six rats per group. The control group consisted of rats receiving only distilled water as drinking water. All other groups received NaF in the amount of 10 mg/kg of body mass/day in their drinking water. In addition, respective animal groups received: NaF + Met group--10 mg of methionine/kg of body mass/day, NaF + Met + E group--10 mg of methionine/kg of body mass/day and 3 mg of vitamin E (tocopheroli acetas)/rat/day and NaF + E group--3 mg of vitamin E/rat/day. Femoral bones and incisor teeth were collected for the study, and the fluoride concentration was determined using a fluoride ion-selective electrode. Fluoride concentration in both bones and teeth was found to be higher in the NaF and NaF + Met groups compared to the control group. In groups NaF + Met + E and NaF + E, the study material contained much lower fluoride concentration compared to the NaF group, while the effect was more prominent in the NaF + E group. The results of the studies indicate that methionine and vitamin E have opposite effects on accumulation of fluorides in hard tissue in rats. By stimulating fluoride accumulation, methionine reduces the adverse effect of fluorides on soft tissue, while vitamin E, which prevents excessive accumulation of fluorides in bones and teeth, protects these tissues from fluorosis. Therefore, it seems that combined application of both compounds would be optimal for the prevention of the adverse effects of chronic fluoride intoxication.

  20. Vitamin E and Health

    Science.gov (United States)

    ... Food Service Resources Additional Resources About FAQ Contact Vitamin E and Health Table of Contents Introduction: Vitamin ... Vitamin E and Other Chronic Diseases References Introduction: Vitamin E and Disease Prevention Vitamin E’s main function ...

  1. Palm vitamin E reduces catecholamines, xanthine oxidase activity and gastric lesions in rats exposed to water-immersion restraint stress

    Directory of Open Access Journals (Sweden)

    Mohd Fahami Nur Azlina

    2012-05-01

    Full Text Available Abstract Background This study examined the effects of Palm vitamin E (PVE and α-tocopherol (α-TF supplementations on adrenalin, noradrenalin, xanthine oxidase plus dehydrogenase (XO + XD activities and gastric lesions in rats exposed to water-immersion restraint stress (WIRS. Methods Sixty male Sprague–Dawley rats (200-250 g were randomly divided into three equal sized groups. The control group was given a normal diet, while the treated groups received the same diet with oral supplementation of PVE or α-TF at 60 mg/kg body weight. After the treatment period of 28 days, each group was further subdivided into two groups with 10 rats without exposing them to stress and the other 10 rats were subjected to WIRS for 3.5 hours. Blood samples were taken to measure the adrenalin and noradrenalin levels. The rats were then sacrificed following which the stomach was excised and opened along the greater curvature and examined for lesions and XO + XD activities. Results The rats exposed to WIRS had lesions in their stomach mucosa. Our findings showed that dietary supplementations of PVE and α-TF were able to reduce gastric lesions significantly in comparison to the stressed control group. WIRS increased plasma adrenalin and noradrenalin significantly. PVE and α-TF treatments reduced these parameters significantly compared to the stressed control. Conclusions Supplementations with either PVE or α-TF reduce the formation of gastric lesions. Their protective effect was related to their abilities to inhibit stress induced elevation of adrenalin and noradrenalin levels as well as through reduction in xanthine oxidase and dehydrogenase activities.

  2. Impact resistant electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Veith, Gabriel M.; Armstrong, Beth L.; Tenhaeff, Wyatt E.; Dudney, Nancy J.

    2017-03-07

    A passively impact resistant composite electrolyte composition includes an electrolyte solvent, up to 2M of an electrolyte salt, and shear thickening ceramic particles having a polydispersity index of no greater than 0.1, an average particle size of in a range of 50 nm to 1 .mu.m, and an absolute zeta potential of greater than .+-.40 mV.

  3. Analysis of liquid water formation in polymer electrolyte membrane (PEM) fuel cell flow fields with a dry cathode supply

    Science.gov (United States)

    Gößling, Sönke; Klages, Merle; Haußmann, Jan; Beckhaus, Peter; Messerschmidt, Matthias; Arlt, Tobias; Kardjilov, Nikolay; Manke, Ingo; Scholta, Joachim; Heinzel, Angelika

    2016-02-01

    PEM fuel cells can be operated within a wide range of different operating conditions. In this paper, the special case of operating a PEM fuel cell with a dry cathode supply and without external humidification of the cathode, is considered. A deeper understanding of the water management in the cells is essential for choosing the optimal operation strategy for a specific system. In this study a theoretical model is presented which aims to predict the location in the flow field at which liquid water forms at the cathode. It is validated with neutron images of a PEM fuel cell visualizing the locations at which liquid water forms in the fuel cell flow field channels. It is shown that the inclusion of the GDL diffusion resistance in the model is essential to describe the liquid water formation process inside the fuel cell. Good agreement of model predictions and measurement results has been achieved. While the model has been developed and validated especially for the operation with a dry cathode supply, the model is also applicable to fuel cells with a humidified cathode stream.

  4. B Vitamins

    Science.gov (United States)

    The B vitamins are B1 (thiamine) B2 (riboflavin) B3 (niacin) B5 (pantothenic acid) B6 B7 (biotin) B12 Folic acid ... help form red blood cells. You can get B vitamins from proteins such as fish, poultry, meat, ...

  5. Large scale simulation of liquid water transport in a gas diffusion layer of polymer electrolyte membrane fuel cells using the lattice Boltzmann method

    Science.gov (United States)

    Sakaida, Satoshi; Tabe, Yutaka; Chikahisa, Takemi

    2017-09-01

    A method for the large-scale simulation with the lattice Boltzmann method (LBM) is proposed for liquid water movement in a gas diffusion layer (GDL) of polymer electrolyte membrane fuel cells. The LBM is able to analyze two-phase flows in complex structures, however the simulation domain is limited due to heavy computational loads. This study investigates a variety means to reduce computational loads and increase the simulation areas. One is applying an LBM treating two-phases as having the same density, together with keeping numerical stability with large time steps. The applicability of this approach is confirmed by comparing the results with rigorous simulations using actual density. The second is establishing the maximum limit of the Capillary number that maintains flow patterns similar to the precise simulation; this is attempted as the computational load is inversely proportional to the Capillary number. The results show that the Capillary number can be increased to 3.0 × 10-3, where the actual operation corresponds to Ca = 10-5∼10-8. The limit is also investigated experimentally using an enlarged scale model satisfying similarity conditions for the flow. Finally, a demonstration is made of the effects of pore uniformity in GDL as an example of a large-scale simulation covering a channel.

  6. The role of water management on the oxygen transport resistance in polymer electrolyte fuel cell with ultra-low precious metal loading

    Science.gov (United States)

    Srouji, A. K.; Zheng, L. J.; Dross, R.; Aaron, D.; Mench, M. M.

    2017-10-01

    Limiting current measurements are used to evaluate oxygen transport resistance in the catalyst layer of a polymer electrolyte fuel cell (PEFC). The pressure independent oxygen transport resistance in the electrode is quantified for two cell architectures and two cathode Pt loadings (0.4 and 0.07 mgPt.cm-2). The compounded effect of the flow field and Pt loading is used to shed light on the nature of the observed transport resistance, especially its response to fundamentally different flow fields, which is shown to directly or indirectly scale with Pt loading in the open literature. By varying gas pressure and using low oxygen concentrations, the total oxygen transport resistance is divided into intermolecular gas diffusion (a pressure-dependent component) and a pressure independent component, which can be attributed to Knudsen diffusion or dissolution film resistance. The pressure-independent oxygen transport resistance in the catalyst layer varies between 13.3 and 34.4 s/m. It is shown that the pressure independent oxygen transport resistance increases with reduced Pt loading, but that effect is greatly exacerbated by using conventional channel/lands. The results indicate that open metallic element architecture improves the oxygen transport resistance in ultra-low Pt loading electrodes, likely due to enhanced water management at the catalyst layer.

  7. Nanoporous polymer electrolyte

    Science.gov (United States)

    Elliott, Brian [Wheat Ridge, CO; Nguyen, Vinh [Wheat Ridge, CO

    2012-04-24

    A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at 25.degree. C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

  8. Porous dendritic copper: an electrocatalyst for highly selective CO 2 reduction to formate in water/ ionic liquid electrolyte

    OpenAIRE

    Huan, Tran Ngoc; Simon, Philippe; Rousse, Gwenaëlle; Génois, Isabelle; Artero, Vincent; Fontecave, Marc

    2016-01-01

    International audience; Copper is currently extensively studied because it provides promising electrodes for carbon dioxide electroreduction. The original combination, reported here, of a nanostructured porous dendritic Cu-based material, characterized by electron microcopy (SEM, TEM) and X-ray diffraction methods, and a water/ionic liquid mixture as the solvent, contributing to CO 2 solubilization and activation, results in a remarkably efficient (large current densities at low overpotential...

  9. Studies on Electrolyte Conductivity and Activity of Dehydrogenase of Chinese Fir and Masson Pine Bare-Root Seedling under Water and Cold Stress

    Institute of Scientific and Technical Information of China (English)

    Yu Fangyuan; Xu Xizeng; Guo Xinbao

    2003-01-01

    The electrolyte conductivity and activity of dehydrogenase of bare-root seedlings of both Chinese fir (Cunningha-mia lanceolata (Lamb.) Hook.) and Masson pine (Pinus massoniana Lamb.) under freezing and desiccation treatments were studied.The results showed that needle electrolyte conductivity of both species increase significantly after freezing treatment and there are nosignificant differences in needle electrolyte conductivity between the two species. The dehydrogenase activity (ARD) of fine roots ofboth Chinese fir and Masson pine was negatively correlated with increasing freezing and desiccation. The results suggest that bothelectrolyte conductivity and dehydrogenase activity could be used as quick indicators of Chinese fir and Masson pine bare-root seed-ling quality.

  10. Analysis of the water balance of polymer electrolyte membrane fuel cells; Untersuchung zum Wasserhaushalt von Polymerelektrolytmembran-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Hakenjos, A.

    2006-09-14

    Within this thesis, instruments for the localised characterisation of fuel cells and fuel cell stacks have been created. The simultaneous multi-channel impedance spectroscopy was implemented and applied to fuel cells for the first time. A measurement device has been developed that can be used to simultaneously apply various localised measurement methods to fuel cells during operation. Within this work, mainly current density and localized impedance measurements were used. Additionally, the temperature distribution of the active fuel cell area was determined and the water condensation was visualised. Several fuel cells have been developed, constructed and assembled to carry out localised characterisation. An algorithm has been developed to evaluate impedance spectra that separate the processes in the fuel cell according to their different time constants. This algorithm is based on a system of physical model equations that provide time- and location-dependent descriptions of the different processes in the cell. This allows the quantitive extraction of physical parameters from the impedance spectroscopy results. To perform localised simulation, a three-dimensional, two-phase, stationary model was adopted cell. A simple one-dimensional fuel cell geometry was used to demonstrate that the three-dimensional model reliably describes the processes under various operation conditions. The model validation was also successfully carried out for various complex fuel cell geometries. With the localised characterisation methods, air flow field geometries of fuel cells were successfully analysed. It could be explained how the microporous coating of the diffusion layer influences the current density distribution. The water balance of a number of different gas flow geometries was successfully characterised. As a result, an optimised flow field design with a double meander has been developed. The water content has been improved so that the efficiency is increased, and the current

  11. Numerical simulation of liquid water and gas flow in a channel and a simplified gas diffusion layer model of polymer electrolyte membrane fuel cells using the lattice Boltzmann method

    OpenAIRE

    Tabe, Yutaka; Lee, Yongju; Chikahisa, Takemi; Kozakai, Masaya

    2009-01-01

    Numerical simulations using the lattice Boltzmann method (LBM) are developed to elucidate the dynamic behavior of condensed water and gas flow in a polymer electrolyte membrane (PEM) fuel cell. Here, the calculation process of the LBM simulation is improved to extend the simulation to a porous medium like a gas diffusion layer (GDL), and a stable and reliable simulation of two-phase flow with large density differences in the porous medium is established. It is shown that dynamic capillary fin...

  12. A zwitterionic gel electrolyte for efficient solid-state supercapacitors

    OpenAIRE

    Peng, Xu; Liu, Huili; Yin, Qin; Wu, Junchi; Chen, Pengzuo; Zhang, Guangzhao; Liu, Guangming; Wu, Changzheng; Xie, Yi

    2016-01-01

    Gel electrolytes have attracted increasing attention for solid-state supercapacitors. An ideal gel electrolyte usually requires a combination of advantages of high ion migration rate, reasonable mechanical strength and robust water retention ability at the solid state for ensuring excellent work durability. Here we report a zwitterionic gel electrolyte that successfully brings the synergic advantages of robust water retention ability and ion migration channels, manifesting in superior electro...

  13. Solid polymer electrolyte water electrolyser based on Nafion-TiO{sub 2} composite membrane for high temperature operation

    Energy Technology Data Exchange (ETDEWEB)

    Baglio, V.; Antonucci, V.; Arico, A.S. [CNR-ITAE, Messina (Italy); Matteucci, F.; Martina, F.; Zama, I. [Tozzi Renewable Energy SpA, Mezzano (Italy); Ciccarella, G. [National Nanotechnology Laboratory (NNL) of INFM-CNR, Distretto Tecnologico ISUFI, Innovazione, Universita del Salento, Lecce (Italy); Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Queretaro Sanfandila (Mexico); Ornelas, R.

    2009-06-15

    A composite Nafion-TiO{sub 2} membrane was manufactured by a recast procedure, using an in-house prepared TiO{sub 2}. This membrane has shown promising properties for high temperature operation in an SPE electrolyser allowing to achieve higher performance with respect to a commercial Nafion 115 membrane. This effect is mainly due to the water retention properties of the TiO{sub 2} filler. A promising increase in electrical efficiency was recorded at low current densities for the composite membrane-based SPE electrolyser at high temperature compared to conventional membrane-based devices. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  14. Vitamine D2 ou vitamine D3?

    OpenAIRE

    MISTRETTA, Virginie; Delanaye, Pierre; Chapelle, Jean-Paul; Souberbielle, Jean-Claude; Cavalier, Etienne

    2008-01-01

    PURPOSE: Nearly one billion people around the world are deficient in vitamin D and need to be supplemented. Vitamin D is available in medicines and fortified foods. It is available in two forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). KEY POINTS: The pharmacopeiae consider these steroid hormones as equivalent and interchangeable. However, several studies have showed that serum level of 25(OH)D is increased more effectively with vitamin D3 than vitamin D2. Vitamin D2 has ...

  15. Vitamin C

    Science.gov (United States)

    ... cataracts AMD and cataracts are two of the leading causes of vision loss in older people. Researchers do not believe that vitamin C and other antioxidants affect the risk of getting AMD. However, research ...

  16. Vitamin A

    Science.gov (United States)

    ... carotenoid is beta-carotene. Beta-carotene is an antioxidant. Antioxidants protect cells from damage caused by substances called ... A can lead to hyperkeratosis or dry, scaly skin. If you get too much vitamin A, you ...

  17. Adsorption of Hydrophobin-Protein Mixtures at the Air-Water Interface: The Impact of pH and Electrolyte.

    Science.gov (United States)

    Tucker, Ian M; Petkov, Jordan T; Penfold, Jeffrey; Thomas, Robert K; Cox, Andrew R; Hedges, Nick

    2015-09-15

    The adsorption of the proteins β-casein, β-lactoglobulin, and hydrophobin, and the protein mixtures of β-casein/hydrophobin and β-lactoglobulin/hydrophobin have been studied at the air-water interface by neutron reflectivity, NR. Changing the solution pH from 7 to 2.6 has relatively little impact on the adsorption of hydrophobin or β-lactoglobulin, but results in a substantial change in the structure of the adsorbed layer of β-casein. In β-lactoglobulin/hydrophobin mixtures, the adsorption is dominated by the hydrophobin adsorption, and is independent of the hydrophobin or β-lactoglobulin concentration and solution pH. At pH 2.6, the adsorption of the β-casein/hydrophobin mixtures is dominated by the hydrophobin adsorption over the range of β-casein concentrations studied. At pH 4 and 7, the adsorption of β-casein/hydrophobin mixtures is dominated by the hydrophobin adsorption at low β-casein concentrations. At higher β-casein concentrations, β-casein is adsorbed onto the surface monolayer of hydrophobin, and some interpenetration between the two proteins occurs. These results illustrate the importance of pH on the intermolecular interactions between the two proteins at the interface. This is further confirmed by the impact of PBS, phosphate buffered saline, buffer and CaCl2 on the coadsorption and surface structure. The results provide an important insight into the adsorption properties of protein mixtures and their application in foam and emulsion stabilization.

  18. The real-time determination of net water transport coefficient based on measurement of water content in the outlet gas in a polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    He, Guangli; Shibata, Kenji; Yamazaki, Yohtaro [Department of Innovative and Engineered Materials, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology (Japan); Abuliti, Abudula [North Japan New Energy Research Center, Hirosaki University, Aomori (Japan)

    2010-08-01

    A numerical approach is developed to determine the real-time Net Water Transport Coefficient (NWTC) based on the experimental water vapor pressure for the cathode and anode outlet obtained by the optical humidity sensors with Tunable Diode Laser Absorption Spectroscopy (TDLAS). The results show that there are sharp vibrations for NWTC in the process of start-up and shut-down. And the time needed for the water transport balance increases with the increase in the current. The balanced NWTC ranges from -0.2 to 0.2, and it increases with the increase in the operation current in the present research. In the view of flooding prevention, it is reasonable to humidify the anode inlet gas with the lower temperature than that of cathode side by decreasing the osmotic-drag water from anode to cathode. (author)

  19. Fluid and Electrolyte Nutrition

    Science.gov (United States)

    Lane, Helen W.; Smith, Scott M.; Leach, Carolyn S.; Rice, Barbara L.

    1999-01-01

    Studies of fluid and electrolyte homeostasis have been completed since the early human space flight programs, with comprehensive research completed on the Spacelab Life Sciences missions SLS-1 and SLS-2 flights, and more recently on the Mir 18 mission. This work documented the known shifts in fluids, the decrease in total blood volume, and indications of reduced thirst. Data from these flights was used to evaluate the nutritional needs for water, sodium, and potassium. Interpretations of the data are confounded by the inadequate energy intakes routinely observed during space flight. This in turn results in reduced fluid intake, as food provides approximately 70% water intake. Subsequently, body weight, lean body mass, total body water, and total body potassium may decrease. Given these issues, there is evidence to support a minimum required water intake of 2 L per day. Data from previous Shuttle flights indicated that water intake is 2285 +/- 715 ml/day (mean +/- SD, n=26). There are no indications that sodium intake or homeostasis is compromised during space flight. The normal or low aldosterone and urinary sodium levels suggest adequate sodium intake (4047 +/- 902 mg/day, n=26). Because excessive sodium intake is associated with hypercalciuria, the recommended maximum amount of sodium intake during flight is 3500 mg/day (i.e., similar to the Recommended Dietary Allowance, RDA). Potassium metabolism appears to be more complex. Data indicate loss of body potassium related to muscle atrophy and low dietary intake (2407 +/- 548 mg/day, n=26). Although possibly related to measurement error, the elevations in blood potassium suggest alterations in potassium homeostasis. The space RDA for minimum potassium intake is 3500 mg/day. With the documented inadequate intakes, efforts are being made to increase dietary consumption of potassium.

  20. Autogenous electrolyte, non-pyrolytically produced solid capacitor structure

    Science.gov (United States)

    Sharp, D.J.; Armstrong, P.S.; Panitz, J.K.G.

    1998-03-17

    A solid electrolytic capacitor is described having a solid electrolyte comprising manganese dioxide dispersed in an aromatic polyamide capable of further cure to form polyimide linkages, the solid electrolyte being disposed between a first electrode made of valve metal covered by an anodic oxide film and a second electrode opposite the first electrode. The electrolyte autogenously produces water, oxygen, and hydroxyl groups which act as healing substances and is not itself produced pyrolytically. Reduction of the manganese dioxide and the water molecules released by formation of imide linkages result in substantially improved self-healing of anodic dielectric layer defects. 2 figs.

  1. Unsuccessful vitamin D treatment

    DEFF Research Database (Denmark)

    Schmedes, Anne; Hey, Henrik; Larsson, Iben

    2012-01-01

    Vitamin D3 (25-OHD3) analyses have increased exponentially and vitamin D deficiency (vitamin D2). Lack of effect of treatment can be due to: 1......) too low dose, 2) incorrect analytical methods when injection treatment (vitamin D2) is used, 3) obesity, 4) seasonal variations, and 5) poor compliance. Treatment is mandatory in order to prevent osteopenia and osteoporosis. Vitamin D3 is more potent than vitamin D2. Injections with vitamin D2 should...... be replaced by vitamin D3....

  2. Effect of salts on the solubility of ionic liquids in water: experimental and electrolyte Perturbed-Chain Statistical Associating Fluid Theory†

    Science.gov (United States)

    Mohammad, Sultan; Schleinitz, Miko; Coutinhoa, João A. P.; Freire, Mara G.

    2016-01-01

    Due to scarce available experimental data, as well as due to the absence of predictive models, the influence of salts on the solubility of ionic liquids (ILs) in water is still poorly understood. To this end, this work addresses the solubility of the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]), at 298.15 K and 0.1 MPa, in aqueous salt solutions (from 0.1 to 1.5 mol kg−1). At salt molalities higher than 0.2 mol kg−1, all salts caused salting-out of [C4C1im][NTf2] from aqueous solution with their strength decreasing in the following order: Al2(SO4)3 > ZnSO4 > K3C6H5O7 > KNaC4H4O6 > K3PO4 > Mg(CH3CO2)2 > K2HPO4 > MgSO4 > KH2PO4 > KCH3CO2. Some of these salts lead however to the salting-in of [C4C1im][NTf2] in aqueous medium at salt molalities lower than 0.20 mol kg−1. To attempt the development of a model able to describe the salt effects, comprising both the salting-in and salting-out phenomena observed, the electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was applied using ion-specific parameters. The gathered experimental data was modelled using ePC-SAFT parameters complemented by fitting a single binary parameter between K+ and the IL-ions to the IL solubility in K3PO4 aqueous solutions. Based on this approach, the description of anion-specific salting-out effects of the remaining potassium salts was found to be in good agreement with experimental data. Remarkably, ePC-SAFT is even able to predict the salting-in effect induced by K2HPO4, based on the single K+/IL-ions binary parameter which was fitted to an exclusively salting-out effect promoted by K3PO4. Finally, ePC-SAFT was applied to predict the influence of other sodium salts on the [C4C1im][NTf2] solubility in water, with experimental data taken from literature, leading to an excellent description of the liquid–liquid phase behaviour. PMID:26575280

  3. Effect of salts on the solubility of ionic liquids in water: experimental and electrolyte Perturbed-Chain Statistical Associating Fluid Theory.

    Science.gov (United States)

    Neves, Catarina M S S; Held, Christoph; Mohammad, Sultan; Schleinitz, Miko; Coutinho, João A P; Freire, Mara G

    2015-12-21

    Due to scarce available experimental data, as well as due to the absence of predictive models, the influence of salts on the solubility of ionic liquids (ILs) in water is still poorly understood. To this end, this work addresses the solubility of the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]), at 298.15 K and 0.1 MPa, in aqueous salt solutions (from 0.1 to 1.5 mol kg(-1)). At salt molalities higher than 0.2 mol kg(-1), all salts caused salting-out of [C4C1im][NTf2] from aqueous solution with their strength decreasing in the following order: Al2(SO4)3 > ZnSO4 > K3C6H5O7 > KNaC4H4O6 > K3PO4 > Mg(CH3CO2)2 > K2HPO4 > MgSO4 > KH2PO4 > KCH3CO2. Some of these salts lead however to the salting-in of [C4C1im][NTf2] in aqueous medium at salt molalities lower than 0.2 mol kg(-1). To attempt the development of a model able to describe the salt effects, comprising both the salting-in and salting-out phenomena observed, the electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was applied using ion-specific parameters. The gathered experimental data was modelled using ePC-SAFT parameters complemented by fitting a single binary parameter between K(+) and the IL-ions to the IL solubility in K3PO4 aqueous solutions. Based on this approach, the description of anion-specific salting-out effects of the remaining potassium salts was found to be in good agreement with experimental data. Remarkably, ePC-SAFT is even able to predict the salting-in effect induced by K2HPO4, based on the single K(+)/IL-ions binary parameter which was fitted to an exclusively salting-out effect promoted by K3PO4. Finally, ePC-SAFT was applied to predict the influence of other sodium salts on the [C4C1im][NTf2] solubility in water, with experimental data taken from literature, leading to an excellent description of the liquid-liquid phase behaviour.

  4. Multi-layered proton-conducting electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae H.; Dorris, Stephen E.; Balachandran, Uthamalingam

    2017-06-27

    The present invention provides a multilayer anode/electrolyte assembly comprising a porous anode substrate and a layered solid electrolyte in contact therewith. The layered solid electrolyte includes a first dense layer of yttrium-doped barium zirconate (BZY), optionally including another metal besides Y, Ba, and Zr (e.g., a lanthanide metal such as Pr) on one surface thereof, a second dense layer of yttrium-doped barium cerate (BCY), and an interfacial layer between and contacting the BZY and BCY layers. The interfacial layer comprises a solid solution of the BZY and BCY electrolytes. The porous anode substrate comprises at least one porous ceramic material that is stable to carbon dioxide and water (e.g., porous BZY), as well as an electrically conductive metal and/or metal oxide (e.g., Ni, NiO, and the like).

  5. Erosive potential of vitamin and vitamin+mineral effervescent tablets.

    Science.gov (United States)

    Wegehaupt, Florian J; Lunghi, Nancy; Hogger, Vanessa M G; Attin, Thomas

    2016-01-01

    The extrinsic sources for erosion-causing acids are primarily acidic beverages and foodstuffs. Effervescent tablets also contain organic acids (e.g. citric, tartaric, malic) in order to form carbon dioxide by contact with water – with the help of the carbonate salts of the tablets. To adequately inform patients about the possible erosive potential of effervescent tablets, this study was undertaken in order to investigate the erosive potential of effervescent tablets (ET), containing either a combination of vitamins and minerals or vitamins only, commercially available in Switzerland. One hundred and ninety-two bovine enamel samples were prepared and allocated to 16 groups (A–H and 1–8; n = 12/group). Samples were eroded (120 s/erosive cycle) in freshly prepared solutions (200 ml/12 samples) comprised of tap water and a supplement as follows: none (control groups, A and 1); vitamin+mineral ET: Qualite and Prix (B), Optisana (C), Well and Active (D), Actilife All in One (E), Berocca (F), Isostar (G) and Qualite and Prix Mg + Vit C (H); vitamin ET: Actilife-Multivitamin (2), Sunlife Vitamin C (3), Optisana Vitamin C (4), Optisana Multivitamin (5), Well and Active Multivitamin (6), Kneipp Vitamin C+Zink (7) and Sunlife Multivitamin (8). Enamel loss was measured using profilometry after 10 and 20 erosive cycles. For the vitamin+mineral ET, no loss was observed in groups B–E. Significantly highest enamel loss (mean ± SD) after 20 cycles was observed for Isostar (5.26 ± 0.76 µm) and Qualite and Prix Mg + Vit C (5.12 ± 0.67 µm). All vitamine ET showed erosive enamel loss. Significantly highest loss was observed for Sunlife Multivitamin (8.45 ± 1.08 µm), while the lowest loss was observed for Actilife-Multivitamin (5.61 ± 1.08 µm) after 20 cycles. Some of the tested effervescent tablets showed a considerable erosive potential and patients should be informed accordingly.

  6. Towards Prognostics of Electrolytic Capacitors

    Data.gov (United States)

    National Aeronautics and Space Administration — A remaining useful life prediction algorithm and degradation model for electrolytic capacitors is presented. Electrolytic capacitors are used in several applications...

  7. Specific electrical conductivity in molten potassium dihydrogen phosphate KH2PO4 - An electrolyte for water electrolysis at ∼300°C

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey Valerievich; Berg, Rolf W.; Petrushina, Irina

    2016-01-01

    The conductivity of pure molten KH2PO4 salt and four mixtures with more or less water (KH2PO4-H2O and KH2PO4-KPO3 systems, respectively) were measured at temperatures of 240-320°C and under their own water vapor pressures. Molten KH2PO4 has been proven to be a promising electrolyte for an elevated...... temperature pressurized water electrolyzer demonstrating high conductivity of ∼0.30Scm-1 at 300°C. The conductivity data are given as polynomial functions of temperature and composition. The melting point of the pure salt under its own water vapor pressure was determined to be ∼272°C....

  8. Simultaneous analysis for water- and fat-soluble vitamins by a novel single chromatography technique unifying supercritical fluid chromatography and liquid chromatography.

    Science.gov (United States)

    Taguchi, Kaori; Fukusaki, Eiichiro; Bamba, Takeshi

    2014-10-03

    Chromatography techniques usually use a single state in the mobile phase, such as liquid, gas, or supercritical fluid. Chromatographers manage one of these techniques for their purpose but are sometimes required to use multiple methods, or even worse, multiple techniques when the target compounds have a wide range of chemical properties. To overcome this challenge, we developed a single method covering a diverse compound range by means of a "unified" chromatography which completely bridges supercritical fluid chromatography and liquid chromatography. In our method, the phase state was continuously changed in the following order; supercritical, subcritical and liquid. Moreover, the gradient of the mobile phase starting at almost 100% CO2 was replaced with 100% methanol at the end completely. As a result, this approach achieved further extension of the polarity range of the mobile phase in a single run, and successfully enabled the simultaneous analysis of fat- and water-soluble vitamins with a wide logP range of -2.11 to 10.12. Furthermore, the 17 vitamins were exceptionally separated in 4min. Our results indicated that the use of dense CO2 and the replacement of CO2 by methanol are practical approaches in unified chromatography covering diverse compounds. Additionally, this is a first report to apply the novel approach to unified chromatography, and can open another door for diverse compound analysis in a single chromatographic technique with single injection, single column and single system.

  9. Simultaneous determination of water-soluble vitamins in SRM 1849 Infant/Adult Nutritional Formula powder by liquid chromatography–isotope dilution mass spectrometry

    Science.gov (United States)

    Assessing dietary intake of vitamins from all sources, including foods, dietary supplements, and fortified foods, would be aided considerably by having analytical methodologies that are capable of simultaneous determination of several vitamins. Vitamins naturally present in foods may occur in diffe...

  10. Electrodes for the hydrogen through water electrolysis using BMI.BF{sub 4} as electrolyte; Eletrodos para a producao de hidrogenio via eletrolise da agua utilizando BMI.BF{sub 4} como eletrolito

    Energy Technology Data Exchange (ETDEWEB)

    Botton, Janine Padilha; Martini, Emilse M.A.; Souza, Michele Oberson de; Souza, Roberto Fernando de [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica. Lab. de Eletroquimica e Catalise]. E-mail: janine@iq.ufrgs.br; Loget, Gabriel [Universite de Rennes 1, Rennes (France). Lab. de Eletroquimica Molecular e Macromolecular. UMR CNRS 6510

    2008-07-01

    The hydrogen production by water electrolysis was tested with different electrocatalysts (nickel, iron alloys containing nickel, chromium and manganese, and molybdenum) in the ionic liquid electrolyte, 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF{sub 4}), 10 vol.% in water. The hydrogen evolution reaction (HER) worked at room temperature with a platinum quasi-reference electrode (PtQRE) applying a -1.7 V potential. The experimental conditions used were determined in previous work and such parameters of operation were confirmed with the electrocatalysts employed in this work. A Hoffman cell apparatus was used to perform the water electrolysis. The current density values, j, obtained were between 3.0 mA cm{sup -2} and 77.5 mA cm{sup -2}. The system efficiency was very high for all electrocatalysts tested, between 97.0% and 99.2%. The molybdenum (Mo) electrode was better than others showing the highest current density value in HER. This behavior has been explained by the lower value of activation energy for the electrolysis reaction when Mo is employed comparing with Pt electrode. The energy activation of the HER using platinum (Pt) as electrocatalyst in an aqueous solution of BMI.BF{sub 4} 10 vol.% was 23.40 kJ mol{sup -1}, whereas with electrode of Mo in the same conditions , was 9.22 kJ mol{sup -1}. In an alkaline aqueous electrolyte (usual medium for such reaction), Mo is less efficient than Pt explaining the lack of published citation using pure Mo as cathode for the HER. The excellent results obtained with a Mo electrode employing ionic liquid as electrolyte show that the hydrogen production can be carried out with cheap electrode material at room temperature, which makes this method economically attractive. (author)

  11. Electrolyte for batteries with regenerative solid electrolyte interface

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jie; Lu, Dongping; Shao, Yuyan; Bennett, Wendy D.; Graff, Gordon L.; Liu, Jun; Zhang, Ji-Guang

    2017-08-01

    An energy storage device comprising: an anode; and a solute-containing electrolyte composition wherein the solute concentration in the electrolyte composition is sufficiently high to form a regenerative solid electrolyte interface layer on a surface of the anode only during charging of the energy storage device, wherein the regenerative layer comprises at least one solute or solvated solute from the electrolyte composition.

  12. Vitamin D

    Science.gov (United States)

    ... Because exposure to sunlight is a risk for skin cancer, you should use sunscreen after a few minutes in the sun. People who do not live in sunny places may not make enough vitamin D. Skin that is exposed to sunshine indoors through a ...

  13. 颅咽管瘤术后水电解质紊乱的临床特点及预后%The clinical characteristics and prognosis of postoperative water-electrolyte disorders following craniopharyngioma surgery

    Institute of Scientific and Technical Information of China (English)

    钟庆丽; 冯凤

    2011-01-01

    目的 探讨成人颅咽管瘤术后水电解质紊乱的临床特点、治疗以及预后.方法 根据术后血钠的变化情况,对57例成人颅咽管瘤术后水电解质紊乱的临床特点和治疗进行了分析.结果 除20例(35.1%)患者术后水电解质正常外,37例(64.9%)患者在术后出现了不同程度和不同类型的水电解质紊乱.其中低渗性脱水(血清钠150 mmol/L)7例(18.9%),等渗性脱水3例(8.1%),典型的"三期"变化6例(16.2%),高钠-低钠交替出现4例(10.8%).结论 颅咽管瘤术后水电解质异常纠正是颅咽管瘤治疗和患者恢复过程中非常重要的方面,需要及时监测其变化并给予针对性的治疗.%Objective To investigate the clinical characteristics, treatment and prognosis of water-electrolyte disorders following adult craniopharyngioma surgery. Methods The alterations of water-electrolyte balance in 57 cases were retrospectively analyzed according to the serum sodium level after adult craniopharyngioma surgery. Results Most patients developed water-electrolyte disorders of different extents and types after craniopharyngioma surgery. Except 20 (35. 0% ) patients, the other 37 (65. 0% ) patients developed various types and degrees of postoperative water-electrolyte disturbances. There were hypotonic dehydration (serum sodium 150mmol/L) in 7 patients ( 18. 9% ) , isotonic dehydration in 3 patients (8. 1% ) , typical triphasic alterations in 6 patients( 16. 2% ) , and alternation between high and low sodium levels in 4 patients( 10. 8% ). Conclusion It is critical for a sound outcome of craniopharyngioma surgery to manage dehydration and endocrine disorders.

  14. Electrolytic hydrogen fuel production with solid polymer electrolyte technology.

    Science.gov (United States)

    Titterington, W. A.; Fickett, A. P.

    1973-01-01

    A water electrolysis technology based on a solid polymer electrolyte (SPE) concept is presented for applicability to large-scale hydrogen production in a future energy system. High cell current density operation is selected for the application, and supporting cell test performance data are presented. Demonstrated cell life data are included to support the adaptability of the SPE system to large-size hydrogen generation utility plants as needed for bulk energy storage or transmission. The inherent system advantages of the acid SPE electrolysis technology are explained. System performance predictions are made through the year 2000, along with plant capital and operating cost projections.

  15. Solid electrolytic fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Masayasu; Yamauchi, Yasuhiro; Kamisaka, Mitsuo; Notomi, Kei.

    1989-04-21

    Concerning a solid electrolytic fuel cell with a gas permeable substrate pipe, a fuel electrode installed on this substrate pipe and an air electrode which is laminated on this fuel electrode with the electrolyte in between, the existing fuel cell of this kind uses crystals of CaMnO3, etc. for the material of the air electrode, but its electric resistance is big and in order to avert this, it is necessary to make the film thickness of the air electrode big. However, in such a case, the entry of the air into its inside worsens and the cell performance cannot develop satisfactorily. In view of the above, in order to obtain a high performance solid electrolytic fuel cell which can improve electric conductivity without damaging diffusion rate of the air, this invention proposes with regard to the aforementioned solid electrolytic fuel cell to install a heat resistant and conductive member inside the above air electrode. 6 figs.

  16. Polymer electrolyte reviews. 1

    Energy Technology Data Exchange (ETDEWEB)

    Mac Callum, J.R.; Vincent, C.A.

    1987-01-01

    The development of polymer electrolytes which have potential applications in battery technology has resulted in an escalation of research into the synthesis of new macromolecular supports and the mechanisms of ionic transport within the solid matrix. Investigation of the properties of polymer electrolytes has brought together polymer chemists and electrochemists, and the understanding of the solubility and transport of electrolytes in organic polymers is now developing from this pooled experience. This book deals with experimental, theoretical and applied aspects of solid solutions of electrolytes used in coordinating polymer matrices. Attention is focused on the synthesis and properties of these new materials, the mechanisms of conduction processes and practical applications, especially with regard to battery technology.

  17. Nanoscale Organic Hybrid Electrolytes

    KAUST Repository

    Nugent, Jennifer L.

    2010-08-20

    Nanoscale organic hybrid electrolytes are composed of organic-inorganic hybrid nanostructures, each with a metal oxide or metallic nanoparticle core densely grafted with an ion-conducting polyethylene glycol corona - doped with lithium salt. These materials form novel solvent-free hybrid electrolytes that are particle-rich, soft glasses at room temperature; yet manifest high ionic conductivity and good electrochemical stability above 5V. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Fast separation and analysis of water-soluble vitamins in spinach by capillary electrophoresis with high voltage%毛细管电泳法高压快速分离分析菠菜中的水溶性维生素

    Institute of Scientific and Technical Information of China (English)

    胡晓琴; 尤慧艳

    2009-01-01

    In capillary electrophoresis, 0 -40 kV (even higher) voltage can be reached by a connecting double-model high voltage power supply. In the article, water-soluble vitamins, VB_1, VB_2, VB_6, VC, calcium D-pantothenate, D-biotin, nicotinic acid and folic acid in vegeta-ble , were separated by using the high voltage power supply under the condition of electrolyte water solution as running buffer. The separation conditions, such as voltage, the concentration of buffer and pH value etc. , were optimized during the experiments. The results showed that eight water-soluble vitamins could be baseline separated in 2. 2 min at 40 kV applied voltage, 25 mmol/L sodium tetraborate buffer solution (pH 8. 8). The water-soluble vitamins in spinach were quantified and the results were satisfied. The linear correlation coefficients of the water-soluble vitamins ranged from 0. 998 1 to 0. 999 9. The detection limits ranged from 0. 2 to 0. 3 mg/L. The average recoveries ranged from 88. 0% to 100. 6% with the relative standard devia-tions (RSD) range of 1. 15% -4. 13% for the spinach samples.%在毛细管电泳法中,通过双模对接高压电源可以获得0~40 kV甚至40 kV以上的超高电压.本研究在40 kV的超高电压下,以纯电解质水溶液为缓冲液,实现了蔬菜中通常含有的8种水溶性维生素(VB_1、VB_2、VB_6、VC、D-泛酸钙、D-生物素、烟酸和叶酸)的快速分离及菠菜样品的定量分析.通过考察电压、缓冲溶液浓度、pH值等因素对分离的影响,确定了优化的实验条件.结果表明,在40 kV高压下,采用25 mmol/L 硼砂-硼酸溶液缓冲液(pH 8.8),菠菜中上述8种水溶性维生素在2.2 min内获得了较好的基线分离.用此方法对菠菜中的水溶性维生素进行定量分析,得到了令人满意的结果.水溶性维生素的线性相关系数范围为 0.998 1~0.999 9,检出限为0.2~0.3 mg/L,在菠菜中的平均加标回收率为88.0% ~100.6%,峰面积的相对标准偏差(RSD)为1

  19. Influence of Different Calcium Levels and Low pH of Water on the Plasma Electrolyte Regulation of a Fresh Water Teleost Fish Cyprinus carpio Var. communies, (Linnaeus, 1958

    Directory of Open Access Journals (Sweden)

    A. Chezhian

    2011-03-01

    Full Text Available The present study investigated low pH with calcium and without calcium treatment on gill histology and ionoregulation of fish, Cyprinus carpio exposed to low pH 4.0 with low (normal water calcium 6 mg/L and low pH 4.0 with added calcium 15 mg/L treatment for a period of 96 h. The light microscopic studies of the processed low pH with low calcium treatment, exposed gills showed marked histological alterations. The lesions of the gills included hypertrophy of the filament and lamellar cells; hyperplasia of the filament and lamellar cells, and deformities of gill arches, filaments and lamellae were seen. But in low pH with high calcium treatment the gill lesins were minimum such as, hypertrophy, hyperplasia and proliferation of chloride cells. In low pH with (normal water low calcium treatment, plasma ionic levels (Na+, K+ Cl- decreased as the exposure period extended. In all the three experiments sodium level showing steep decrease ranging from 0.405, 21.382 to 8.411 at the end of 24 h to 32.965, 57.350 and 18.915 at the end of 96 h, respectively. Low pH with high calcium treatment, the fish exhibited only a minor depression in the plasma ionic levels showing minimum decrease of 4.952, 20.128 and 7.702 at the end of 96 h, respectively. Impact on gills and ionoregulation were minimum in low pH with added calcium level due to the ameliorative effects of calcium. The significant alteration in both the histology and electrolyte levels can serve as a biomarker of pollutant exposure and effects.

  20. Electrolyte low concentrations effects on the the rheology of water and bentonitic clays basis drilling fluids; Efeito de baixas concentracoes de eletrolitos na reologia de fluidos de perfuracao a base de agua e argilas bentoniticas

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, Luciana Viana [Universidade Federal, Campina Grande, PB (Brazil). Engenharia de Processos]. E-mail: lucianaa@labdes.ufpb.br; Viana, Josiane Dantas; Farias, Kassie Vieira; Lira, Helio de Lucena; Ferreira, Heber Carlos [Universidade Federal, Campina Grande, PB (Brazil). Dept. de Engenharia de Materiais]. E-mail: josianedantas@bol.com.br; kassievieira@bol.com.br; helio@dema.ufpb.br; heber@dema.ufpb.br; Franca, Kepler Borges [Universidade Federal, Campina Grande, PB (Brazil). Dept. de Engenharia Quimica]. E-mail: kepler@labdes.ufpb.br

    2003-07-01

    The aim of this work is to study the effect of low electrolytes concentration on the rheology of the water based oil well drilling fluids and bentonite clays from Boa Vista, PB. It were selected seven samples of bentonite clays (four from industry and three from natural polycationic clay treated with concentrated Na{sub 2}CO{sub 3} solution). The drilling fluids were prepared with a concentration of 4.86 % w/w, according to PETROBRAS norms and treated with different CaCl{sub 2} + MgCl{sub 2} concentration. After, the drilling fluids were submitted to a cure for 24 hours and measured apparent viscosity (AV), plastic viscosity (PV) and water loss (WL). To study the effect of the electrolyte on the rheology of the dispersions it was developed a factorial design 2{sup 2} + 3 test in the central point. The results showed that the addition of CaCl{sub 2} + MgCl{sub 2} caused a degradation of the drilling fluids prepared with industrialized clays, as showed by the decrease in AV and PV and great increase in WL. Also, it was observed an increase in AV and a decrease in PV in the drilling fluids prepared with natural clays treated with Na{sub 2}CO{sub 3}, conducting a flocculated-gel state. (author)

  1. Solid electrolyte membranes and the system to produce hydrogen from thermally decomposed water by solar energy; Taiyo energy riyo ni yoru mizu no chokusetsu netsubunkai kara no suiso seizoyo

    Energy Technology Data Exchange (ETDEWEB)

    Nigara, K.; Watanabe, K.; Kawamura, K.; Kawada, T.; Mizusaki, J.; Ishigame, M. [Tohoku University, Sendai (Japan). Research Institute for Scientific Measurements

    1996-10-27

    For conversion of solar heat to transportable energy, hydrogen production by direct thermal decomposition of water using concentrated high-temperature solar heat was studied. Water vapor is injected into the tubular target with high melting point and high oxygen permeability at high temperature while heating the target by concentrated solar heat over 2000K. Oxygen in decomposed gas is discharged through an oxygen permeable membrane to extract hydrogen. Solid electrolyte is used as one of the target materials. Oxygen gas in the high-oxygen partial pressure site changes into oxygen ion by accepting two electrons at the target surface, and returns to neutral oxygen gas in the low-oxygen partial pressure site by discharging two electrons at the surface after permeation through oxygen vacancy. In the case of n-type solid electrolyte, to obtain constant permeation of a large amount of oxygen, flow of a large amount of electrons is indispensable in the opposite direction to oxygen ion. Among [(ZrO2)(1-x)(CeO2)x](0.9)(CaO)(0.1), materials of 0.4-0.5 in x seems to be useful as the target material. 7 refs., 7 figs.

  2. Effect of Electrolyte Composition on Characteristics of Plasma Electrolysis Nitrocarburizing

    Science.gov (United States)

    Tavakoli, H.; Mousavi Khoie, S. M.; Marashi, S. P. H.; Bolhasani, O.

    2013-08-01

    In this article, the effect of electrolyte composition on the characteristics of generated layer by plasma electrolytic nitrocarburizing process is studied. The characterization of the layer was carried out by means of SEM, x-ray diffraction, and EIS techniques. The relationship between workpiece temperature and the chemical composition of electrolyte was determined during the process. Three distinct regions in the temperature-voltage curves were observed. The effect of electrolyte's composition on the electrical parameters such as critical voltage, voltage of plasma formation, current density, and electrolyte conductivity was investigated. XRD studies showed that in addition to nitride phases, Fe3O4 phase also is generated. Moreover, EIS studies indicated that the corrosion resistance of the samples processed with higher water contents is less than the samples processed with lower water contents.

  3. Vitamin D Test

    Science.gov (United States)

    ... products and services. Advertising & Sponsorship: Policy | Opportunities Vitamin D Tests Share this page: Was this page helpful? Also known as: Ergocalciferol (Vitamin D 2 ); Cholecalciferol (Vitamin D 3 ); Calcidiol (25-hydroxyvitamin ...

  4. Vitamin A Test

    Science.gov (United States)

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Vitamin A Share this page: Was this page helpful? ... Related tests: Complete Blood Count , Comprehensive Metabolic Panel , Vitamin B12 and Folate , Vitamin D Tests , Iron Tests , ...

  5. Vitamin A blood test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003570.htm Vitamin A blood test To use the sharing features on this page, please enable JavaScript. The vitamin A test measures the level of vitamin A ...

  6. Vitamin D and Health

    Science.gov (United States)

    ... Service Resources Additional Resources About FAQ Contact Vitamin D and Health Table of Contents Vitamin D Deficiency: ... and Colds Risk of Premature Death References Vitamin D Deficiency: A Global Concern If you live north ...

  7. Simultaneous Determination of 4 Kinds of Water-soluble Vitamins in Compound Vitamin Oral Solution by HPLC%HPLC法同时测定复合维生素口服液中4种水溶性维生素的含量

    Institute of Scientific and Technical Information of China (English)

    白靖; 向柏; 申磊; 何朝星; 张贵琴; 曹德英

    2011-01-01

    目的:建立测定复合维生素口服液中4种水溶性维生素的含量测定方法.方法:采用高效液相色谱法.同时测定复合维生素口服液中烟酰胺、维生素B6、维生素B1、维生素B2磷酸酯钠的含量,色谱柱为Diamonsil C18,流动相为己烷磺酸钠溶液-甲醇-冰醋酸(690:303:7,V/V/V),检测波长为280nm.结果:烟酰胺、维生素B6、维生素B1、维生素B2磷酸酯钠能实现良好的分离,检测浓度线性范围分别为87.5~700.0、7.50~60.0、25~200、17.5~140.0μg·mL-1(r均大于0.999 3);平均回收率分别为101.3%、99.5%、100.0%和98.4%;RSD分别为0.5%、0.6%、0.6%和0.9%.结论:本方法简便、快速、准确且重复性好,为含有上述维生素类成分的多维复方制剂及保健产品的质量控制提供了参考.%OBJECTIVE: To establish a method for simultaneous determination of 4 kinds of water-soluble vitamins in Compound vitamin oral solution. METHODS: HPLC method was adopted. The content of 4 kinds of water-soluble vitamins, including nicotinamide, vitamin B6, vitamin B1 and vitamin B2 sodium phosphate, were determined by HPLC. A Diamonsil C18 column was used. The mobile phase consisted of sodium hexanesulfonate solution-methanol-acetic acid (690:303: 7, VIVIV) and the UV detection wavelength was 280 nm. RESULTS: 4 components were separated well and the calibration curves showed good linearity within the range of 87.5 -700.0μg·mL-1 for nicotinamide, 7.5 - 60.0 μg·mL-1 for vitamin Be, 25 - 200 (μg·mL-1 for vitamin B1, and 17.5 - 140.0 μg·rnL-1 for vitamin B2 sodium phosphate, respectively (r>0.999 3). The average recoveries were 101.3% (RSD= 0.5% ), 99.5% (RSD=0.6% ), 100.0% (RSD=0.6% ), 98.4% (RSD=0.9% ), respectively. CONCLUSION: The proposed method is convenient, fast, accurate and reproducible. It provides reference for quality control of vitamins components of compound vitamin formulations and health product.

  8. Electrolyte ions and glutathione enzymes as stress markers in ...

    African Journals Online (AJOL)

    Electrolyte ions and glutathione enzymes as stress markers in Argania spinosa subjected to drought ... African Journal of Biotechnology ... Responses to soil drying and re -watering were measured at physiological and biochemical levels.

  9. Calibrating the X-ray attenuation of liquid water and correcting sample movement artefacts during in operando synchrotron X-ray radiographic imaging of polymer electrolyte membrane fuel cells.

    Science.gov (United States)

    Ge, Nan; Chevalier, Stéphane; Hinebaugh, James; Yip, Ronnie; Lee, Jongmin; Antonacci, Patrick; Kotaka, Toshikazu; Tabuchi, Yuichiro; Bazylak, Aimy

    2016-03-01

    Synchrotron X-ray radiography, due to its high temporal and spatial resolutions, provides a valuable means for understanding the in operando water transport behaviour in polymer electrolyte membrane fuel cells. The purpose of this study is to address the specific artefact of imaging sample movement, which poses a significant challenge to synchrotron-based imaging for fuel cell diagnostics. Specifically, the impact of the micrometer-scale movement of the sample was determined, and a correction methodology was developed. At a photon energy level of 20 keV, a maximum movement of 7.5 µm resulted in a false water thickness of 0.93 cm (9% higher than the maximum amount of water that the experimental apparatus could physically contain). This artefact was corrected by image translations based on the relationship between the false water thickness value and the distance moved by the sample. The implementation of this correction method led to a significant reduction in false water thickness (to ∼0.04 cm). Furthermore, to account for inaccuracies in pixel intensities due to the scattering effect and higher harmonics, a calibration technique was introduced for the liquid water X-ray attenuation coefficient, which was found to be 0.657 ± 0.023 cm(-1) at 20 keV. The work presented in this paper provides valuable tools for artefact compensation and accuracy improvements for dynamic synchrotron X-ray imaging of fuel cells.

  10. Glasslike Behavior in Aqueous Electrolyte Solutions

    CERN Document Server

    Turton, David A; Hefter, Glenn; Buchner, Richard; Wynne, Klaas; 10.1063/1.2906132

    2009-01-01

    When salts are added to water, the viscosity generally increases suggesting the ions increase the strength of the water's hydrogen-bond network. However, infrared pump-probe measurements on electrolyte solutions have found that ions have no influence on the rotational dynamics of water molecules implying no enhance-ment or breakdown of the hydrogen-bond network. Here we report optical Kerr-effect and dielectric relaxa-tion spectroscopic measurements, which have enabled us to separate the effects of rotational and transitional motions of the water molecules. These data show that electrolyte solutions behave like a supercooled liquid approaching a glass transition in which rotational and translational molecular motions are decoupled. It is now possible to understand previously conflicting viscosity data, nuclear magnetic resonance relaxation, and ultrafast infrared spectroscopy in a single unified picture.

  11. Glasslike behavior in aqueous electrolyte solutions.

    Science.gov (United States)

    Turton, David A; Hunger, Johannes; Hefter, Glenn; Buchner, Richard; Wynne, Klaas

    2008-04-28

    When salts are added to water, generally the viscosity increases, suggesting that the ions increase the strength of the water's hydrogen-bond network. However, infrared pump-probe measurements on electrolyte solutions have found that ions have no influence on the rotational dynamics of water molecules, implying no enhancement or breakdown of the hydrogen-bond network. Here, we report optical Kerr effect and dielectric relaxation spectroscopic measurements, which have enabled us to separate the effects of rotational and transitional motions of the water molecules. These data show that electrolyte solutions behave like a supercooled liquid approaching a glass transition in which rotational and translational molecular motions are decoupled. It is now possible to understand previously conflicting viscosity data, nuclear magnetic resonance relaxation, and ultrafast infrared spectroscopy in a single unified picture.

  12. The buffer effect in neutral electrolyte supercapacitors

    DEFF Research Database (Denmark)

    Thrane Vindt, Steffen; Skou, Eivind M.

    2016-01-01

    to a change in the redox potential of water in opposite directions on the two electrodes, resulting in the wider stability window. The magnitude of this effect is suggested to be dependent on the buffer capacity, rather than the intrinsic pH value of the electrolyte. This is confirmed by studying the impact...... of addition of a buffer to such systems. It is shown that a 56 % higher dynamic storage capacity may be achieved, simply by controlling the buffer capacity of the electrolyte. The model system used, is based on a well-known commercial activated carbon (NORIT™ A SUPRA) as the electrode material, aqueous...... potassium nitrate as the electrolyte and potassium phosphates as the buffer system....

  13. Gel electrolytes and electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmann, Sven; Bunte, Christine; Mikhaylik, Yuriy V.; Viner, Veronika G.

    2017-09-05

    Gel electrolytes, especially gel electrolytes for electrochemical cells, are generally described. In some embodiments, the gel electrolyte layers comprise components a) to c). Component a) may be at least one layer of at least one polymer comprising polymerized units of: a1) at least one monomer containing an ethylenically unsaturated unit and an amido group and a2) at least one crosslinker. Component b) may be at least one conducting salt and component c) may be at least one solvent. Electrodes may comprise the components a), d) and e), wherein component a) may be at least one layer of at least one polymer as described herein. Component d) may be at least one electroactive layer and component e) may be at least one ceramic layer. Furthermore, electrochemical cells comprising component a) which may be at least one layer of at least one polymer as described herein, are also provided.

  14. Seebeck effect in electrolytes.

    Science.gov (United States)

    Chikina, I; Shikin, V; Varlamov, A A

    2012-07-01

    We study Seebeck effect in liquid electrolytes, starting from its simple neutral analog--thermodiffusion (so-called Ludwig-Soret or Soret effect). It is observed that when two or more subsystems of mobile particles are subjected to the temperature gradient, various types of them respond to it differently. In the case when these fractions, with different mobility parameters (Soret coefficients), are oppositely charged (a case typical for electrolytes), the nonhomogeneous internal electric field is generated. The latter field prevents these fractions from space separation and determines the intensity of the appearing Seebeck effect.

  15. Multichannel discharge between jet electrolyte cathode and jet electrolyte anode

    NARCIS (Netherlands)

    Shakirova, E. F.; Gaitsin, Al. F.; Son, E. E.

    2011-01-01

    We present the results of an experimental study of multichannel discharge between a jet electrolyte cathode and jet electrolyte anode within a wide range of parameters. We pioneer the reveal of the burning particularities and characteristics of multichannel discharge with jet electrolyte and droplet

  16. Facts about Vitamin K

    Science.gov (United States)

    Facts about Vitamin K 1 R. Elaine Turner and Wendy J. Dahl 2 FCS8666 Figure 1. Vitamin K is mostly found in vegetables, especially green ... ColognePhotos/iStock/Thinkstock, © ColognePhotos Why do we need vitamin K? Vitamin K is one of the fat- ...

  17. Vitamin B-12

    Science.gov (United States)

    ... in vitamin B12 if I’m vegetarian or vegan?ResourcesNational Institutes of Health: MedlinePlus, Vitamin B12 Last Updated: March 2017 This article was contributed by: familydoctor.org editorial staff Tags: B12, B12 deficiency, diet, nutrition, vitamin B12, vitamins Food and Nutrition, Nutrients ...

  18. Vitamin B6

    Science.gov (United States)

    ... Consumer Datos en español Health Professional Other Resources Vitamin B6 Fact Sheet for Consumers Have a question? ... out more about vitamin B6? Disclaimer What is vitamin B6 and what does it do? Vitamin B6 ...

  19. Vitamin B12

    Science.gov (United States)

    ... Consumer Datos en español Health Professional Other Resources Vitamin B12 Fact Sheet for Consumers Have a question? ... out more about vitamin B12? Disclaimer What is vitamin B12 and what does it do? Vitamin B12 ...

  20. Facts about Vitamin C

    Science.gov (United States)

    Facts About Vitamin C 1 Linda B. Bobroff and Isabel Valentín-Oquendo 2 FCS8702 Why do we need vitamin C? Vitamin C, also known as ascorbic acid, has a ... maintain healthy body tissues and the immune system. Vitamin C also helps the body absorb iron from ...

  1. FATSOLUBLE VITAMINS AND SPORT

    Directory of Open Access Journals (Sweden)

    Novica Bojanić

    2013-12-01

    Full Text Available Vitamins are the cell biocatalysts, indispensable factors in performing the basic body functions. Fat-soluble vitamins are not involved in processes related to musscle contractions and energy expenditure, but they can affect physical performance indirectly because they are important for immune function (vitamin A, vitamin D, vitamin E, antioxidant function (vitamin A, vitamin E or bone methabolism (vitamin D, vitamin K. Currently there are no clear recommendations for increase of fat-solubile vitamins intake in athletes, as well as evidence that athletic performance may be improved due to fat-solubile vitamins supplementation. In a small number of studies, it was shown that an antioxidant effect of beta carotene and vitamin E can prevent muscle damage and facilitate recovery after exercise. Also, athletes who perform the exercises in the halls should be informed about the necessity of sun exposure, as vitamin D is synthesised in the skin. Most athletes are not familiar with their needs for vitamins and trace elements, and take these compounds as supplements without consulting a nutritionist. It is important to emphasize that liposulubile vitamins are deposited in the body and can cause hypervitaminosis and toxic effects if taken in excess. It is indisputable that the lack of any fat-soluble vitamin cause problems in normal physiological processes, but supplementation is generally not required in athlets who have a well-balanced diet.

  2. Electrochemical potential at the interface between carbon nanotubes and electrolyte

    Institute of Scientific and Technical Information of China (English)

    LU Jian-wei; WANG Wan-lu; WU Zi-hua; WANG Yong-tian

    2004-01-01

    The dependences of electrochemical potential at the interface between carbon nanotubes and electrolyte upon temperature and electrolyte concentration are studied. Carbon nanotubes were synthesized by hot filament chemical vapor deposition with Si as the substrate. Four substances were tested: NaCl solution, KCl solution, water and alcohol. It is found that for NaCl and KCl solutions, at the interface, there is a large electrochemical potential which increases with temperature and is larger for an electrolyte of higher concentration. There is a significant field effect of carbon nanotubes with electrolyte as the gate,and the effect depends on the ionizability of the electrolyte. Such physicochemical property invests carbon nanotube a potential application in nanoelectronics.

  3. Foaming-electrolyte fuel cell

    Science.gov (United States)

    Nanis, L.; Saunders, A. P.

    1970-01-01

    Foam structure feeds fuel gas solution into electrolyte. Fuel gas reacts at static, three-phase interface between fuel gas, electrolyte, and electrode material. The foam forms an electrical contact between main body of electrolyte and the electrode, and aids in removal of by-products of the chemical reaction.

  4. EFEKTIVITAS MIKROEMULSI O/W DENGAN SURFAKTAN NON IONIK DALAM MENGHAMBAT FOTOOKSIDASI VITAMIN C PADA MODEL MINUMAN (Effectiveness of Oil-in-Water Microemulsions with Nonionic Surfactants in Inhibiting Photooxidation of Vitamin C in Beverage Model

    Directory of Open Access Journals (Sweden)

    Lutfi Suhendra

    2013-06-01

    (o/w dibentuk dari campuran minyak–surfaktan (15:85 v/v dengan perbandingan surfaktan Tween 80:Span 80:Tween 20 = 92:5,5: 2,5 (% v/v dengan kadar air 65%. Mikroemulsi o/w diuji stabilitas terhadap pH dan pengenceran dengan cara mengencerkan mikroemulsi dengan media air dan buffer sitrat (pH: 3,5; 4,5 dan aquades pH 6,5 dengan proporsi 1:1. 1:9 dan 1:99, selanjutnya mikroemulsi o/w yang telah dilakukan pengenceran dengan pH berbeda ini diuji stabilitasnya pada pemanasan 105 °C selama 5 jam dan stabilitas penyimpanan selama 8 minggu pada suhu ruang. Model minuman terdiri dari larutan vitamin C (450 mg/L, asam sitrat (1% dan sukrosa (6%. Mikroemulsi o/w yang ditambahkan ke dalam model minuman adalah mikroemulsi diencerkan 50 kali dan 100 kali dengan aquades pH 6,5. Selanjutnya ditambahkan dengan/tanpa eritrosin sehingga masing-masing larutan mengandung eritrosin 5 ppm sebagai sensitiser. Sampel tersebut kemudian dipapar dengan lampu fl uoresen dengan intensitas cahaya 2000 lux. Konsentrasi vitamin C diukur dengan metode ribofl avin-sensitized photodynamic UV spectrophotometry tiap 2 jam. Mikroemulsi o/w stabil pada pH 3,5 sampai 6,5 dan pengenceran (1:1. 1:9 dan 1:99, pemanasan dan penyimpanan. Mikroemulsi o/w diencerkan 100 kali efektif meningkatkan stabilitas vitamin C, namun mikroemulsi o/w diencerkan 50 kali lebih efektif untuk menghambat laju kerusakan vitamin C akibat fotooksidasi pada model minuman. Kata kunci: Mikroemulsi, vitamin C, fotooksidsi, surfaktan

  5. Platinum nanoparticles on carbon-nanotube support prepared by room-temperature reduction with H2 in ethylene glycol/water mixed solvent as catalysts for polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Zheng, Yuying; Dou, Zhengjie; Fang, Yanxiong; Li, Muwu; Wu, Xin; Zeng, Jianhuang; Hou, Zhaohui; Liao, Shijun

    2016-02-01

    Polyol approach is commonly used in synthesizing Pt nanoparticles in polymer electrolyte membrane fuel cells. However, the application of this process consumes a great deal of time and energy, as the reduction of precursors requires elevated temperatures and several hours. Moreover, the ethylene glycol and its oxidizing products bound to Pt are difficult to remove. In this work, we utilize the advantages of ethylene glycol and prepare Pt nanoparticles through a room-temperature hydrogen gas reduction in an ethylene glycol/water mixed solvent, which is followed by subsequent harvesting by carbon nanotubes as electrocatalysts. This method is simple, facile, and time-efficient, as the entire room-temperature reduction process is completed in a few minutes. As the solvent changes from water to an ethylene glycol/water mix, the size of Pt nanoparticles varies from 10 to 3 nm and their shape transitions from polyhedral to spherical. Pt nanoparticles prepared in a 1:1 volume ratio mixture of ethylene glycol/water are uniformly dispersed with an average size of ∼3 nm. The optimized carbon nanotube-supported Pt electrocatalyst exhibits excellent methanol oxidation and oxygen reduction activities. This work demonstrates the potential use of mixed solvents as an approach in materials synthesis.

  6. Recent results on aqueous electrolyte cells

    KAUST Repository

    Wessells, Colin

    2011-03-01

    The improved safety of aqueous electrolytes makes aqueous lithium-ion batteries an attractive alternative to commercial cells utilizing flammable and expensive organic electrolytes. Two important issues relating to their use have been addressed in this work. One is the extension of the usable voltage range by the incorporation of lithium salts, and the other is the investigation of a useful negative electrode reactant, LiTi 2(PO 4) 3. The electrochemical stability of aqueous lithium salt solutions containing two lithium salts, LiNO 3 and Li 2SO 4, has been characterized using a constant current technique. In both cases, concentrated solutions had effective electrolyte stability windows substantially greater than that of pure water under standard conditions. At an electrolyte leakage current of 10 μA cm -2 between two platinum electrodes in 5 M LiNO 3 the cell voltage can reach 2.0 V, whereas with a leakage current of 50 μA cm -2 it can reach 2.3 V. LiTi 2(PO 4) 3 was synthesized using a Pechini method and cycled in pH-neutral Li 2SO 4. At a reaction potential near the lower limit of electrolyte stability, an initial discharge capacity of 118 mAh g -1 was measured at a C/5 rate, while about 90% of this discharge capacity was retained after 100 cycles. This work demonstrates that it is possible to have useful aqueous electrolyte lithium-ion batteries using the LiTi 2(PO 4) 3 anode with cell voltages of 2 V and above. © 2010 Elsevier B.V. All rights reserved.

  7. Gel polymer electrolytes for batteries

    Science.gov (United States)

    Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William

    2014-11-18

    Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at 25.degree. C.

  8. Status and applicability of solid polymer electrolyte technology to electrolytic hydrogen and oxygen production

    Science.gov (United States)

    Titterington, W. A.

    1973-01-01

    The solid polymer electrolyte (SPE) water electrolysis technology is presented as a potential energy conversion method for wind driven generator systems. Electrolysis life and performance data are presented from laboratory sized single cells (7.2 sq in active area) with high cell current density selected (1000 ASF) for normal operation.

  9. Comparative Safety and Efficacy Profile of a Novel Oil in Water Vaccine Adjuvant Comprising Vitamins A and E and a Catechin in Protective Anti-Influenza Immunity

    Directory of Open Access Journals (Sweden)

    Sapna Patel

    2017-05-01

    Full Text Available Non-replicating vaccines, such as those based on recombinant proteins, require adjuvants and delivery systems, which have thus far depended on mimicking pathogen danger signals and strong pro-inflammatory responses. In search of a safer and more efficacious alternative, we tested whether vaccinations with influenza recombinant hemagglutinin (HA mixed with a novel vegetable oil in water emulsion adjuvant (Natural Immune-enhancing Delivery System, NIDS, based on the immune-enhancing synergy of vitamins A and E and a catechin, could protect against intra-nasal challenge with live influenza virus. Vaccinations of inbred Brag Albino strain c (BALB/c mice, with HA mixed with NIDS compared to other adjuvants, i.e., a squalene oil in water emulsion (Sq. oil, and the Toll Like Receptor 3 (TLR3 agonist Poly (I:C, induced significantly lower select innate pro-inflammatory responses in serum, but induced significantly higher adaptive antibody and splenic T Helper 1 (TH1 or TH2, but not TH17, responses. Vaccinations with NIDS protected against infection, as measured by clinical scores, lung viral loads, and serum hemagglutination inhibition titers. The NIDS exhibited a strong dose sparing effect and the adjuvant action of NIDS was intact in the outbred CD1 mice. Importantly, vaccinations with the Sq. oil, but not NIDS, induced a significantly higher Serum Amyloid P component, an acute phase reactant secreted by hepatocytes, and total serum IgE. Thus, the NIDS may be used as a clinically safer and more efficacious vaccine adjuvant against influenza, and potentially other infectious diseases.

  10. Vitamin D and allergies

    Directory of Open Access Journals (Sweden)

    Gafvelin Guro

    2013-01-01

    Full Text Available An increasing amount of evidence has established that the biologically active form of vitamin D, 1,25-dihydroxy vitamin D3, possesses immunoregulatory properties. Vitamin D exerts its effects through binding to the nuclear vitamin D receptor (VDR, which is expressed by cells of the immune system. Most of the immunological effects mediated by vitamin D-VDR are regulatory, inhibiting adaptive immune responses. It has become apparent that the incidence of vitamin D insufficiency is surprisingly high in the general population. A link between low vitamin D serum levels and the increased prevalence of allergic diseases has been proposed. This possible connection has been investigated in numerous studies on associations between vitamin D serum concentrations and different allergic conditions, as well as studies on the effect of vitamin D supplementation. Although there is some evidence for a protective role of vitamin D in asthma, no consensus on the role of vitamin D in allergic disease has yet been reached. Still, treatment strategies involving vitamin D supplementation to risk groups, combinatorial corticosteroid and vitamin D treatment in asthma and vitamin D as an immunomodulator in allergen specific immunotherapy show promise for the future.

  11. Electrolytes for advanced batteries

    Energy Technology Data Exchange (ETDEWEB)

    Blomgren, G.E. [Energizer, Westlake, OH (United States)

    1999-09-01

    The choices of the components of the electrolyte phase for advanced batteries (lithium and lithium ion batteries) are very sensitive to the electrodes which are used. There are also a number of other requirements for the electrolyte phase, which depend on the cell design and the materials chosen for the battery. The difficulty of choice is compounded when the cell is a rechargeable one. This paper looks at each of these requirements and the degree to which they are met for lithium and lithium ion batteries. The discussion is broken into sections on anode or negative electrode stability requirements, cathode or positive electrode stability requirements, conductivity needs, viscosity and wetting requirements. The effects of these properties and interactions on the performance of batteries are also discussed. (orig.)

  12. Nanoporous hybrid electrolytes

    KAUST Repository

    Schaefer, Jennifer L.

    2011-01-01

    Oligomer-suspended SiO2-polyethylene glycol nanoparticles are studied as porous media electrolytes. At SiO2 volume fractions, , bracketing a critical value y ≈ 0.29, the suspensions jam and their mechanical modulus increase by more than seven orders. For >y, the mean pore diameter is close to the anion size, yet the ionic conductivity remains surprisingly high and can be understood, at all , using a simple effective medium model proposed by Maxwell. SiO 2-polyethylene glycol hybrid electrolytes are also reported to manifest attractive electrochemical stability windows (0.3-6.3 V) and to reach a steady-state interfacial impedance when in contact with metallic lithium. © 2010 The Royal Society of Chemistry.

  13. Electrochemical polymer electrolyte membranes

    CERN Document Server

    Fang, Jianhua; Wilkinson, David P

    2015-01-01

    Electrochemical Polymer Electrolyte Membranes covers PEMs from fundamentals to applications, describing their structure, properties, characterization, synthesis, and use in electrochemical energy storage and solar energy conversion technologies. Featuring chapters authored by leading experts from academia and industry, this authoritative text: Discusses cutting-edge methodologies in PEM material selection and fabricationPoints out important challenges in developing PEMs and recommends mitigation strategies to improve PEM performanceAnalyzes the cur

  14. Electrolyte Concentrates Treat Dehydration

    Science.gov (United States)

    2009-01-01

    Wellness Brands Inc. of Boulder, Colorado, exclusively licensed a unique electrolyte concentrate formula developed by Ames Research Center to treat and prevent dehydration in astronauts returning to Earth. Marketed as The Right Stuff, the company's NASA-derived formula is an ideal measure for athletes looking to combat dehydration and boost performance. Wellness Brands also plans to expand with products that make use of the formula's effective hydration properties to help treat conditions including heat stroke, altitude sickness, jet lag, and disease.

  15. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... mail Consumer Updates RSS Feed Download PDF (422 K) On this page: Why Buy Vitamins? Vitamin Facts ... body absolutely needs: vitamins A, C, D, E, K, and the B vitamins (thiamine, riboflavin, niacin, pantothenic ...

  16. Electrolyte materials - Issues and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Balbuena, Perla B. [Department of Chemical Engineering, and Department of Materials Science and Engineering, Texas A and M University, College Station, Texas, 77843 (United States)

    2014-06-16

    Electrolytes are vital components of an electrochemical energy storage device. They are usually composed of a solvent or mixture of solvents and a salt or a mixture of salts which provide the appropriate environment for ionic conduction. One of the main issues associated with the selection of a proper electrolyte is that its electronic properties have to be such that allow a wide electrochemical window - defined as the voltage range in which the electrolyte is not oxidized or reduced - suitable to the battery operating voltage. In addition, electrolytes must have high ionic conductivity and negligible electronic conductivity, be chemically stable with respect to the other battery components, have low flammability, and low cost. Weak stability of the electrolyte against oxidation or reduction leads to the formation of a solid-electrolyte interphase (SEI) layer at the surface of the cathode and anode respectively. Depending on the materials of the electrolyte and those of the electrode, the SEI layer may be composed by combinations of organic and inorganic species, and it may exert a passivating role. In this paper we discuss the current status of knowledge about electrolyte materials, including non-aqueous liquids, ionic liquids, solid ceramic and polymer electrolytes. We also review the basic knowledge about the SEI layer formation, and challenges for a rational design of stable electrolytes.

  17. A bio-inspired, small molecule electron-coupled-proton buffer for decoupling the half-reactions of electrolytic water splitting.

    Science.gov (United States)

    Rausch, Benjamin; Symes, Mark D; Cronin, Leroy

    2013-09-18

    Electron-coupled-proton buffers (ECPBs) allow H2 and O2 evolution to be separated from each other in time during the electrolysis of water. Natural photosynthetic systems achieve an analogous feat during water splitting and employ a range of intermediate redox mediators such as quinone derivatives to aid this process. Drawing on this natural example, we show that a low molecular weight quinone derivative is capable of decoupling H2 evolution from O2 evolution at scale during electrochemical water splitting. This work could significantly lower the cost of ECPBs, paving the way for their more widespread adoption in water splitting.

  18. Lemon (Citrus limon, Burm.f.) essential oil enhances the trans-epidermal release of lipid-(A, E) and water-(B6, C) soluble vitamins from topical emulsions in reconstructed human epidermis.

    Science.gov (United States)

    Valgimigli, L; Gabbanini, S; Berlini, E; Lucchi, E; Beltramini, C; Bertarelli, Y L

    2012-08-01

    Topical bioavailability of lipid- and water-soluble vitamins is a critical issue for protecting or anti-ageing formulations. Using 17-day-old SkinEthic(®) reconstructed human epidermis, we investigated (at 34°C) the role of lemon EO in enhancing the penetration of α-tocopherol (E) and retinyl acetate (A), pyridoxine (B(6)) and ascorbic acid (C), released from O/W or W/O emulsions. D-limonene, α-pinene and p-cymene (65.9, 2.2 and 0.5%w/w of the oil) had skin permeability coefficients Ps (10(-3) cm h(-1)) of 0.56 ± 0.03 (or 0.73 ± 0.02), 0.72 ± 0.05 (or 0.98 ± 0.05) and 0.84 ± 0.04 (or 1.14 ± 0.04), respectively, when incorporated in a W/O (or O/W) emulsion. Vitamins B6, C and A had Ps values of (3.0 ± 0.4) × 10(-3), (7.9 ± 0.6) × 10(-3) and (0.37 ± 0.02) × 10(-5) cm h(-1), respectively, and their flux through the skin was enhanced by a factor of 4.1, 3.4 and 5.8, respectively, in the presence of lemon EO. The penetration of vitamin E was nine-fold enhanced. Lemon EO produced only reversible modification of TEWL, and it is a safe and effective penetration enhancer for topical administration of lipid- and water-soluble vitamins.

  19. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12 and folate). AAFP cites two categories of vitamins. ... magnesium, and vitamin E (for children and adolescents) vitamin B-12, iron, folic acid, and vitamins E and D ( ...

  20. Kanamycin Sulphate Loaded PLGA-Vitamin-E-TPGS Long Circulating Nanoparticles Using Combined Coating of PEG and Water-Soluble Chitosan

    Science.gov (United States)

    Mustafa, Sanaul

    2017-01-01

    Kanamycin sulphate (KS) is a Mycobacterium tuberculosis protein synthesis inhibitor. Due to its intense hydrophilicity, KS is cleared from the body within 8 h. KS has a very short plasma half-life (2.5 h). KS is used in high concentrations to reach the therapeutic levels in plasma, which results in serious nephrotoxicity/ototoxicity. To overcome aforementioned limitations, the current study aimed to develop KS loaded PLGA-Vitamin-E-TPGS nanoparticles (KS-PLGA-TPGS NPs), to act as an efficient carrier for controlled delivery of KS. To achieve a substantial extension in blood circulation, a combined design, affixation of polyethylene glycol (PEG) to KS-PLGA-TPGS NPs and adsorption of water-soluble chitosan (WSC) (cationic deacetylated chitin) to particle surface, was raised for surface modification of NPs. Surface modified NPs (KS-PEG-WSC NPs) were prepared to provide controlled delivery and circulate in the bloodstream for an extended period of time, thus minimizing dosing frequency. In vivo pharmacokinetics and in vivo biodistribution following intramuscular administration were investigated. NPs surface charge was close to neutral +3.61 mV and significantly affected by the WSC coating. KS-PEG-WSC NPs presented striking prolongation in blood circulation, reduced protein binding, and long drew-out the blood circulation half-life with resultant reduced kidney sequestration vis-à-vis KS-PLGA-TPGS NPs. The studies, therefore, indicate the successful formulation development of KS-PEG-WSC NPs with reduced frequency of dosing of KS indicating low incidence of nephrotoxicity/ototoxicity.

  1. 水溶性维生素核磁共振定量分析的研究%Studies of NMR Quantitative Analysis for Water-Soluble Vitamins

    Institute of Scientific and Technical Information of China (English)

    张烨; 刘小鹏; 张友杰

    2011-01-01

    药物核磁共振定量分析法,操作简便,样品用量少,定性鉴定和定量分析同步完成,无须被测物的标准对照品,只须一般内标即可完成定量分析,分析速度和精密度可以达到或接近HPLC法.作为药物的水溶性维生素,中国药典中还没有核磁共振定量分析方法.实验数据表明,用核磁共振定量分析法与中国药典中提供的水溶性维生素分析法的分析结果十分吻合,可以达到药品市场监管的要求.%NMR quantitative analysis of drug is the method with simple operation and use just a few amount of samples. The method can accomplish the qualitative as well as the quantitative analysis simultaneously, and do not need any standard compound but only the common internal standard for the quantitative analysis. The analysis speed and the precision of the method is close to the HPLC method. In this paper, the results of determination for water-soluble vitamin by NMR quantitative analysis with chemical a nalysis have been compared . The experiment shows the results of the NMR quantitative analysis are coincident with the result of the chemical method. Therefore, the NMR quantitative analysis method can be used market regulation of drugs.

  2. Kanamycin Sulphate Loaded PLGA-Vitamin-E-TPGS Long Circulating Nanoparticles Using Combined Coating of PEG and Water-Soluble Chitosan

    Directory of Open Access Journals (Sweden)

    Sanaul Mustafa

    2017-01-01

    Full Text Available Kanamycin sulphate (KS is a Mycobacterium tuberculosis protein synthesis inhibitor. Due to its intense hydrophilicity, KS is cleared from the body within 8 h. KS has a very short plasma half-life (2.5 h. KS is used in high concentrations to reach the therapeutic levels in plasma, which results in serious nephrotoxicity/ototoxicity. To overcome aforementioned limitations, the current study aimed to develop KS loaded PLGA-Vitamin-E-TPGS nanoparticles (KS-PLGA-TPGS NPs, to act as an efficient carrier for controlled delivery of KS. To achieve a substantial extension in blood circulation, a combined design, affixation of polyethylene glycol (PEG to KS-PLGA-TPGS NPs and adsorption of water-soluble chitosan (WSC (cationic deacetylated chitin to particle surface, was raised for surface modification of NPs. Surface modified NPs (KS-PEG-WSC NPs were prepared to provide controlled delivery and circulate in the bloodstream for an extended period of time, thus minimizing dosing frequency. In vivo pharmacokinetics and in vivo biodistribution following intramuscular administration were investigated. NPs surface charge was close to neutral +3.61 mV and significantly affected by the WSC coating. KS-PEG-WSC NPs presented striking prolongation in blood circulation, reduced protein binding, and long drew-out the blood circulation half-life with resultant reduced kidney sequestration vis-à-vis KS-PLGA-TPGS NPs. The studies, therefore, indicate the successful formulation development of KS-PEG-WSC NPs with reduced frequency of dosing of KS indicating low incidence of nephrotoxicity/ototoxicity.

  3. Breastfeeding: Vitamin D Supplementation

    Science.gov (United States)

    ... Weight Breastfeeding Micronutrient Malnutrition State and Local Programs Vitamin D Supplementation Recommend on Facebook Tweet Share Compartir ... not provide infants with an adequate intake of vitamin D. Most breastfed infants are able to synthesize ...

  4. Vitamin D Pooling Project

    Science.gov (United States)

    The Vitamin D Pooling Project of Rarer Cancers brought together investigators from 10 cohorts to conduct a large prospective epidemiologic study of the association between vitamin D status and seven rarer cancers.

  5. Vitamin B1

    Science.gov (United States)

    ... Prize Alfred Nobel's Life and Work Teachers' Questionnaire Vitamin B1 - About The Chicken Farm educational game and ... the game window. Reading: "Christian Eijkman, Beriberi and Vitamin B1" - Who was Eijkman and why did he ...

  6. Vitamin Deficiency Anemia

    Science.gov (United States)

    ... are unique to specific vitamin deficiencies. Folate-deficiency anemia risk factors include: Undergoing hemodialysis for kidney failure. ... the metabolism of folate. Vitamin B-12 deficiency anemia risk factors include: Lack of intrinsic factor. Most ...

  7. Vitamin B1

    Science.gov (United States)

    ... Prize Alfred Nobel's Life and Work Teachers' Questionnaire Vitamin B1 - About The Chicken Farm educational game and ... the game window. Reading: "Christian Eijkman, Beriberi and Vitamin B1" - Who was Eijkman and why did he ...

  8. 基于电解水技术的果蔬消毒机改良设计%Improved design of fruit and vegetable disinfecting machine based on electrolytic water technology

    Institute of Scientific and Technical Information of China (English)

    崔因; 陈亦仁; 郭晓英

    2013-01-01

    针对现有果蔬消毒机的问题进行改良设计,采用电解水消毒技术替代传统的臭氧水消毒方法,解决传统消毒方式产生隐患的问题.该机为多功能设计,根据用户需要进行不同选择,对不同的食物分类消毒清洁;轻巧便携式机体、不同食材分筐消毒的设计和侧边透明的设计以及人性化的选择界面更符合人们的操作习惯.%Improved design for the defects of the existing fruit and vegetable disinfecting machines,through the use of electrolytic water disinfection technology to replace conventional ozone water disinfection,which solve the hidden dangers of traditional disinfection methods.This machine has multi-functional design,according to the different needs of the user and satisfying different foods classified disinfection.It is comfortable for operating habits for the lightweight and portable body,different ingredients different disinfection baskets and side transparent design and humane choice interface design.

  9. Vitamins, Are They Safe?

    OpenAIRE

    Hadi Hamishehkar; Farhad Ranjdoost; Parina Asgharian; Ata Mahmoodpoor; Sarvin Sanaie

    2016-01-01

    The consumption of a daily multivitamin among people all over the world is dramatically increasing in recent years. Most of the people believe that if vitamins are not effective, at least they are safe. However, the long term health consequences of vitamins consumption are unknown. This study aimed to assess the side effects and possible harmful and detrimental properties of vitamins and to discuss whether vitamins can be used as safe health products or dietary supplements. We performed a MED...

  10. Perpendicularly Aligned, Anion Conducting Nanochannels in Block Copolymer Electrolyte Films

    Energy Technology Data Exchange (ETDEWEB)

    Arges, Christopher G.; Kambe, Yu; Suh, Hyo Seon; Ocola, Leonidas E.; Nealey, Paul F.

    2016-03-08

    Connecting structure and morphology to bulk transport properties, such as ionic conductivity, in nanostructured polymer electrolyte materials is a difficult proposition because of the challenge to precisely and accurately control order and the orientation of the ionic domains in such polymeric films. In this work, poly(styrene-block-2-vinylpyridine) (PSbP2VP) block copolymers were assembled perpendicularly to a substrate surface over large areas through chemical surface modification at the substrate and utilizing a versatile solvent vapor annealing (SVA) technique. After block copolymer assembly, a novel chemical vapor infiltration reaction (CVIR) technique selectively converted the 2-vinylpyridine block to 2-vinyl n-methylpyridinium (NMP+ X-) groups, which are anion charge carriers. The prepared block copolymer electrolytes maintained their orientation and ordered nanostructure upon the selective introduction of ion moieties into the P2VP block and post ion-exchange to other counterion forms (X- = chloride, hydroxide, etc.). The prepared block copolymer electrolyte films demonstrated high chloride ion conductivities, 45 mS cm(-1) at 20 degrees C in deionized water, the highest chloride ion conductivity for anion conducting polymer electrolyte films. Additionally, straight-line lamellae of block copolymer electrolytes were realized using chemoepitaxy and density multiplication. The devised scheme allowed for precise and accurate control of orientation of ionic domains in nanostructured polymer electrolyte films and enables a platform for future studies that examines the relationship between polymer electrolyte structure and ion transport.

  11. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

    DEFF Research Database (Denmark)

    2001-01-01

    A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various thermopl......A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes...... electrolyte membrane by hot-press. The fuel cell can operate at temperatures up to at least 200 °C with hydrogen-rich fuel containing high ratios of carbon monoxide such as 3 vol% carbon monoxide or more, compared to the carbon monoxide tolerance of 10-20 ppm level for Nafion$m(3)-based polymer electrolyte...

  12. Facts about Vitamin D

    Science.gov (United States)

    ... Gorse/iStock/Thinkstock.com Food Eggs, sardines, and salmon contain vitamin D. Most fluid milk and some brands of ... 2. Typical Vitamin D Content in Food Food Vitamin D in IU (mcg) Salmon, cooked, 3 oz. 320 (8) Sardines, canned in ...

  13. Vitamin D and diabetes

    DEFF Research Database (Denmark)

    Wolden-Kirk, Heidi; Overbergh, Lut; Christesen, Henrik Thybo

    2011-01-01

    Experimental evidence indicates that vitamin D may play a role in the defense against type 1 diabetes (T1D) as well as type 2 diabetes (T2D). Epidemiological data have established a link between vitamin D deficiency and an increased incidence of both T1D and T2D, whereas early and long-term vitamin...

  14. Photo-electrochemical Oxidation of Organic C1 Molecules over WO3 Films in Aqueous Electrolyte: Competition Between Water Oxidation and C1 Oxidation.

    Science.gov (United States)

    Reichert, Robert; Zambrzycki, Christian; Jusys, Zenonas; Behm, R Jürgen

    2015-11-01

    To better understand organic-molecule-assisted photo-electrochemical water splitting, photo-electrochemistry and on-line mass spectrometry measurements are used to investigate the photo-electrochemical oxidation of the C1 molecules methanol, formaldehyde, and formic acid over WO3 film anodes in aqueous solution and its competition with O2 evolution from water oxidation O2 (+) and CO2 (+) ion currents show that water oxidation is strongly suppressed by the organic species. Photo-electro-oxidation of formic acid is dominated by formation of CO2 , whereas incomplete oxidation of formaldehyde and methanol prevails, with the selectivity for CO2 formation increasing with increasing potential and light intensity. The mechanistic implications for the photo-electro-oxidation of the organic molecules and its competition with water oxidation, which could be derived from this novel approach, are discussed.

  15. Solid state electrolyte systems

    Energy Technology Data Exchange (ETDEWEB)

    Pederson, L.R.; Armstrong, B.L.; Armstrong, T.R. [Pacific Northwest Lab., Richland, WA (United States)] [and others

    1997-12-01

    Lanthanum gallates are a new family of solid electrolytes that exhibit high ionic conductivity and are stable to high temperatures. Compositions have been developed that are as much as a factor of two more conductive than yttria-stabilized zirconia at a given temperature, through partial replacement of lanthanum by calcium, strontium, and/or barium and through partial replacement of gallium by magnesium. Oxide powders were prepared using combustion synthesis techniques developed in this laboratory; these were sintered to >95% of theoretical density and consisted of a single crystalline phase. Electrical conductivities, electron and ion transference numbers, thermal expansion, and phase behavior were evaluated as a function of temperature and oxygen partial pressure. A key advantage of the use of lanthanum gallate electrolytes in solid oxide fuel cells is that the temperature of operation may be lowered to perhaps 800 C, yet provide approximately the same power density as zirconia-based cells operating at 1000 C. Ceramic electrolytes that conduct both oxygen ions and electrons are potentially useful to passively separate pure oxygen from an air source at low cost. In such materials, an oxygen ion flux in one direction is charge-compensated by an opposing electron flux. The authors have examined a wide range of mixed ion and electron conducting perovskite ceramics in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, where M = Sr, Ca, and Ba, and N = Pr, Mn, Ni, Cu, Ti, and Al, as well as mixed conducting brownmillerite ceramics, and have characterized oxygen permeation behavior, defect chemistry, structural and phase stability, and performance as cathodes.

  16. Effectiveness of fortification of drinking water with iron and vitamin C in the reduction of anemia and improvement of nutritional status in children attending day-care centers in Belo Horizonte, Brazil.

    Science.gov (United States)

    Rocha, Daniela da Silva; Capanema, Flávio Diniz; Netto, Michele Pereira; de Almeida, Carlos Alberto Nogueira; Franceschini, Sylvia do Carmo Castro; Lamounier, Joel Alves

    2011-12-01

    Because of the high prevalence of iron-deficiency anemia in Brazil, individual control measures tend to be ineffective, and fortification of foods with iron is considered the most effective method to fight anemia. To evaluate the effectiveness of fortification of drinking water with iron and vitamin C in the reduction of anemia in children in day-care centers in Belo Horizonte, Brazil. This before-and-after study evaluated 318 children aged 6 to 74 months. Identification data and data on socioeconomic variables were collected; anthropometric and biochemical measurements were performed before and after 5 months of fortification of water with 5 mg of elemental iron and 50 mg of ascorbic acid per liter. The fortified water was used for drinking and cooking at the day-care center. Wilcoxon's nonparametric test was used to evaluate the differences in continuous variables, and McNemar's test was used to compare the prevalence rates of anemia. The prevalence of anemia decreased significantly from 29.3% before fortification to 7.9% at the end of the study, with a significant increase in hemoglobin levels. Reductions in the prevalence rates of stunting and underweight were observed. Fortification of water with iron and vitamin C significantly reduced the prevalence of anemia and improved nutritional status among children attending day-care centers.

  17. Critical role of the semiconductor-electrolyte interface in photocatalytic performance for water-splitting reactions using Ta3N5 particles

    KAUST Repository

    Nurlaela, Ela

    2014-08-26

    Distinct photocatalytic performance was observed when Ta3N 5 was synthesized from commercially available Ta2O 5 or from Ta2O5 prepared from TaCl5 via the sol-gel route. With respect to photocatalytic O2 evolution with Ag+ as a sacrificial reagent, the Ta3N5 produced from commercial Ta2O5 exhibited higher activity than the Ta3N5 produced via the sol-gel route. When the Ta3N5 photocatalysts were decorated with Pt nanoparticles in a similar manner, the Ta3N5 from the sol-gel route exhibited higher photocatalytic hydrogen evolution activity from a 10% aqueous methanol solution than Ta3N5 prepared from commercial Ta2O5 where no hydrogen can be detected. Detailed surface and bulk characterizations were conducted to obtain fundamental insight into the resulting photocatalytic activities. The characterization techniques, including XRD, elemental analysis, Raman spectroscopy, UV-vis spectroscopy, and surface-area measurements, revealed only negligible differences between these two photocatalysts. Our thorough characterization of the surface properties demonstrated that the very thin outermost layer of Ta3N5, with a thickness of a few nanometers, consists of either the reduced state of tantalum (TaN) or an amorphous phase. The extent of this surface layer was likely dependent on the nature of precursor oxide surfaces. DFT calculations based on partially oxidized Ta3N4.83O0.17 and N deficient Ta3N4.83 consisting of reduced Ta species well described the optoelectrochemical properties obtained from the experiments. Electrochemical and Mott-Schottky analyses demonstrated that the surface layer drastically affects the energetic picture at the semiconductor-electrolyte interface, which can consequently affect the photocatalytic performance. Chemical etching of the surface of Ta3N5 particles to remove this surface layer unites the photocatalytic properties with the photocatalytic performance of these two materials. Mott-Schottky plots of these chemically etched Ta3N5 materials

  18. The Application of PBL Teaching Method in Water-electrolyte Metabolism and Acid-base Balance Teaching%PBL教学法在水、电解质和酸碱平衡教学中的应用

    Institute of Scientific and Technical Information of China (English)

    叶俊; 章宏伟; 黄华兴

    2015-01-01

    Objective: To investigate the advantage of PBL teaching method in water-electrolyte metabolism and acid-base balance teaching. Method:Choose 6 classes of students from Nanjing medical university and randomly divided into experimental group (n=79) and control group (n=78), the experimental group using PBL teaching method and the control group using traditional LBL teaching method, evaluating these two methods by analyze the average scores of the test and the survey. Results:The average scores of experimental group were higher than that in the control group (p=0.026). The survey showed that the experimental group was better in autonomous learning, case analysis, teamwork and using the theoretical knowledge and clinical cases than control group. Conclusion:PBL teaching method was much better than LBL in water-electrolyte metabolism and acid-base balance teaching.%目的::探讨PBL(problem-based learning)教学法在水、电解质和酸碱平衡教学中的应用优势。方法:选取南京医科大学2011级临床医学七年制6个班级的学生,按自然班随机分为实验组(n=79)和对照组(n=78),实验组采用PBL教学模式,对照组采用传统教学模式(LBL),通过调查问卷及课后测试对两种教学模式进行综合评价。结果:实验组理论测试成绩明显优于对照组(p=0.026),调查问卷显示:PBL组在自主学习能力、病例分析能力、团队协作能力以及在掌握理论知识与临床疾病的联系方面均优于LBL组。结论:与LBL教学法相比,PBL教学法在水、电解质和酸碱平衡教学中应用效果更好,优势更明显。

  19. Alternative membranes for polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, A.K.; Pitchumani, S.; Sridhar, P.; Shukla, A.K. [Central Electrochemical Research Inst., Karaikudi (India)

    2009-07-01

    Nafion, a perfluoro-sulfonated membrane, is utilized as a membrane electrolyte in polymer electrolyte fuel cells (PEFCs). However, to realize optimum PEFC performance, the Nafion membrane needs to be fully humidified, making the system quite costly. Therefore, in order to solve this problem, alternative membrane electrolytes that could operate under low humidity conditions are needed. This paper reported on composite Nafion membranes with ceramic/inorganic fillers such as silica and mesoporous zirconium phosphate (MZP). Silica was impregnated to the Nafion matrix by a unique water hydrolysis sol-gel route and casted as a composite membrane while MZP, a solid-super-acid-proton-conducting medium as well as water absorbing material was synthesized by a co-assembly technique and impregnated to the Nafion matrix to form a composite membrane. The performance of the PEFCs with Nafion membrane and composite membranes was tested with hydrogen/oxygen gas and hydrogen/air feeds at varying relative humidity (RH) values under ambient conditions. It was concluded that under RH value as low as 18 per cent, the PEFC with Nafion membrane delivers a peak-power density of only 130 mW/square centimeter.

  20. A zwitterionic gel electrolyte for efficient solid-state supercapacitors.

    Science.gov (United States)

    Peng, Xu; Liu, Huili; Yin, Qin; Wu, Junchi; Chen, Pengzuo; Zhang, Guangzhao; Liu, Guangming; Wu, Changzheng; Xie, Yi

    2016-05-26

    Gel electrolytes have attracted increasing attention for solid-state supercapacitors. An ideal gel electrolyte usually requires a combination of advantages of high ion migration rate, reasonable mechanical strength and robust water retention ability at the solid state for ensuring excellent work durability. Here we report a zwitterionic gel electrolyte that successfully brings the synergic advantages of robust water retention ability and ion migration channels, manifesting in superior electrochemical performance. When applying the zwitterionic gel electrolyte, our graphene-based solid-state supercapacitor reaches a volume capacitance of 300.8 F cm(-3) at 0.8 A cm(-3) with a rate capacity of only 14.9% capacitance loss as the current density increases from 0.8 to 20 A cm(-3), representing the best value among the previously reported graphene-based solid-state supercapacitors, to the best of our knowledge. We anticipate that zwitterionic gel electrolyte may be developed as a gel electrolyte in solid-state supercapacitors.

  1. A zwitterionic gel electrolyte for efficient solid-state supercapacitors

    Science.gov (United States)

    Peng, Xu; Liu, Huili; Yin, Qin; Wu, Junchi; Chen, Pengzuo; Zhang, Guangzhao; Liu, Guangming; Wu, Changzheng; Xie, Yi

    2016-05-01

    Gel electrolytes have attracted increasing attention for solid-state supercapacitors. An ideal gel electrolyte usually requires a combination of advantages of high ion migration rate, reasonable mechanical strength and robust water retention ability at the solid state for ensuring excellent work durability. Here we report a zwitterionic gel electrolyte that successfully brings the synergic advantages of robust water retention ability and ion migration channels, manifesting in superior electrochemical performance. When applying the zwitterionic gel electrolyte, our graphene-based solid-state supercapacitor reaches a volume capacitance of 300.8 F cm-3 at 0.8 A cm-3 with a rate capacity of only 14.9% capacitance loss as the current density increases from 0.8 to 20 A cm-3, representing the best value among the previously reported graphene-based solid-state supercapacitors, to the best of our knowledge. We anticipate that zwitterionic gel electrolyte may be developed as a gel electrolyte in solid-state supercapacitors.

  2. Electrolyte depletion in white-nose syndrome bats

    Science.gov (United States)

    Cryan, Paul M.; Meteyer, Carol Uphoff; Blehert, David S.; Lorch, Jeffrey M.; Reeder, DeeAnn M.; Turner, Gregory G.; Webb, Julie; Behr, Melissa; Verant, Michelle L.; Russell, Robin E.; Castle, Kevin T.

    2013-01-01

    The emerging wildlife disease white-nose syndrome is causing widespread mortality in hibernating North American bats. White-nose syndrome occurs when the fungus Geomyces destructans infects the living skin of bats during hibernation, but links between infection and mortality are underexplored. We analyzed blood from hibernating bats and compared blood electrolyte levels to wing damage caused by the fungus. Sodium and chloride tended to decrease as wing damage increased in severity. Depletion of these electrolytes suggests that infected bats may become hypotonically dehydrated during winter. Although bats regularly arouse from hibernation to drink during winter, water available in hibernacula may not contain sufficient electrolytes to offset winter losses caused by disease. Damage to bat wings from G. destructans may cause life-threatening electrolyte imbalances.

  3. Rediscovering vitamin D

    Directory of Open Access Journals (Sweden)

    Nasr Anaizi

    2010-11-01

    Full Text Available Over the past 2 years there has been a radical change in standard clinical practice with respect to vitamin D. As a result of a growing body of knowledgeable physicians are assessing the vitamin D nutritional status of their patients and prescribing aggressive repletion regimens of a vitamin D supplement. The present paper summarizes some basic information about this essential nutrient and reviews some of the more recent data implicating vitamin D deficiency in disease etiology with an emphasis on cardiovascular disease and cancer. Finally a rational approach to the dosing of vitamin D in different patient populations is provided.

  4. Dedicated nuclear facilities for electrolytic hydrogen production

    Science.gov (United States)

    Foh, S. E.; Escher, W. J. D.; Donakowski, T. D.

    1979-01-01

    An advanced technology, fully dedicated nuclear-electrolytic hydrogen production facility is presented. This plant will produce hydrogen and oxygen only and no electrical power will be generated for off-plant use. The conceptual design was based on hydrogen production to fill a pipeline at 1000 psi and a 3000 MW nuclear base, and the base-line facility nuclear-to-shaftpower and shaftpower-to-electricity subsystems, the water treatment subsystem, electricity-to-hydrogen subsystem, hydrogen compression, efficiency, and hydrogen production cost are discussed. The final conceptual design integrates a 3000 MWth high-temperature gas-cooled reactor operating at 980 C helium reactor-out temperature, direct dc electricity generation via acyclic generators, and high-current density, high-pressure electrolyzers based on the solid polymer electrolyte approach. All subsystems are close-coupled and optimally interfaced and pipeline hydrogen is produced at 1000 psi. Hydrogen costs were about half of the conventional nuclear electrolysis process.

  5. Vitamin C and Infections

    Directory of Open Access Journals (Sweden)

    Harri Hemilä

    2017-03-01

    Full Text Available In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. A total of 148 animal studies indicated that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. The most extensively studied human infection is the common cold. Vitamin C administration does not decrease the average incidence of colds in the general population, yet it halved the number of colds in physically active people. Regularly administered vitamin C has shortened the duration of colds, indicating a biological effect. However, the role of vitamin C in common cold treatment is unclear. Two controlled trials found a statistically significant dose–response, for the duration of common cold symptoms, with up to 6–8 g/day of vitamin C. Thus, the negative findings of some therapeutic common cold studies might be explained by the low doses of 3–4 g/day of vitamin C. Three controlled trials found that vitamin C prevented pneumonia. Two controlled trials found a treatment benefit of vitamin C for pneumonia patients. One controlled trial reported treatment benefits for tetanus patients. The effects of vitamin C against infections should be investigated further.

  6. Vitamin K and thrombosis.

    Science.gov (United States)

    Merli, Geno J; Fink, James

    2008-01-01

    Vitamin K was discovered in the 1930s during cholesterol metabolism experiments in chickens. It is a fat-soluble vitamin which occurs naturally in plants as phylloquinone (vitamin K1) and is produced by gram-negative bacteria in the human gastrointestinal tract as menaquinone (vitamin K2). This vitamin was found to be essential for normal functioning of hemostasis. In addition, a number of clinical conditions in which vitamin K deficiency was found to be the underlying pathophysiologic problem were discovered. These conditions include hemorrhagic disease of the newborn, obstructive jaundice, and malabsorption syndromes. The importance of this vitamin has become more apparent with the discovery of the anticoagulant warfarin which is a vitamin K antagonist. There are millions of patients on this therapy for a variety of thrombogenic conditions such as atrial fibrillation, deep vein thrombosis, pulmonary embolism, and prosthetic cardiac valves. The wide use of this narrow therapeutic index drug has resulted in significant risk for major bleeding. Vitamin K serves as one of the major reversing agent for patients over-anticoagulated with warfarin. In the past few years, research has focused on new areas of vitamin K metabolism, which include bone and endovascular metabolism; cell growth, regulation, migration, and proliferation; cell survival, apoptosis, phagocytosis, and adhesion. These new areas of research highlight the significance of vitamin K but raise new clinical questions for patients who must be maintained on long-term warfarin therapy.

  7. Nonclassical Vitamin D Actions

    Directory of Open Access Journals (Sweden)

    Armin Zittermann

    2010-03-01

    Full Text Available It is becoming increasingly clear that vitamin D has a broad range of actions in the human body. Besides its well-known effects on calcium/phosphate homeostasis, vitamin D influences muscle function, cardiovascular homeostasis, nervous function, and the immune response. Vitamin D deficiency/insufficiency has been associated with muscle weakness and a high incidence of various chronic diseases such as cardiovascular disease, cancer, multiple sclerosis, and type 1 and 2 diabetes. Most importantly, low vitamin D status has been found to be an independent predictor of all-cause mortality. Several recent randomized controlled trials support the assumption that vitamin D can improve muscle strength, glucose homeostasis, and cardiovascular risk markers. In addition, vitamin D may reduce cancer incidence and elevated blood pressure. Since the prevalence of vitamin D deficiency/insufficiency is high throughout the world, there is a need to improve vitamin D status in the general adult population. However, the currently recommended daily vitamin D intake of 5–15 µg is too low to achieve an adequate vitamin D status in individuals with only modest skin synthesis. Thus, there is a need to recommend a vitamin D intake that is effective for achieving adequate circulating 25-hydroxyvitamin D concentrations (>75 nmol/L.

  8. [VITAMIN D AND PREGNANCY].

    Science.gov (United States)

    Hitrova-Nikolova, St; Nikolov, A

    2015-01-01

    This arcicle reviews the role of vitimin D during pregnancy. Adequate intake of vitamin D during pregnancy is very important for the health of mother and infant. A number of epidemiological data worldwide show widespread suboptimal levels of vitamin D in pregnant women. Vitamin D deficiency may be associated with an increased risk of infection, bacterial vaginosis, pre-eclampsia, low serum vitamin D levels in the newborn and others. There are not universal recommendations for dosage and intake of vitamin D for pregnant women in the world. It is recommended that serum level of vitamin D in all pregnant women and its adequate supplementation. Normal maternal vitamin D levels would provide sufficient its accumulation in the fetus.

  9. The vitamin K controversy.

    Science.gov (United States)

    Huysman, M W; Sauer, P J

    1994-04-01

    Discussion about the efficacy and safety of vitamin K prophylaxis has recently restarted. In this review, new developments in diagnosis of vitamin K deficiency (including vitamin K plasma levels and protein induced by vitamin K absence [PIVKA]-II detection) and therapy of early, classic, and late hemorrhagic disease of the newborn are highlighted. Special attention is brought to the efficacy of preventing early and late hemorrhagic disease. The recently described association between intramuscular vitamin K administration and cancer is debated. The very high plasma levels, the intramuscular injection itself, or the adjuvants in the solution might all be responsible. These factors are all absent in oral administration. Therefore, we recommend repeated oral administration for preventing classic and late hemorrhagic disease of the newborn. Additionally, we recommend maternal supplementation of vitamin K for preventing early hemorrhagic disease of the newborn, especially when the mother is using medications that interfere with vitamin K metabolism.

  10. Gelled Electrolytes For Lithium Batteries

    Science.gov (United States)

    Nagasubramanian, Ganesan; Attia, Alan; Halpert, Gerald

    1993-01-01

    Gelled polymer electrolyte consists of polyacrylonitrile (PAN), LiBF4, and propylene carbonate (PC). Thin films of electrolyte found to exhibit stable bulk conductivities of order of 10 to the negative 3rd power S/cm at room temperature. Used in thinfilm rechargeable lithium batteries having energy densities near 150 W h/kg.

  11. Mechanistic insights into lithium ion battery electrolyte degradation - a quantitative NMR study.

    Science.gov (United States)

    Wiemers-Meyer, S; Winter, M; Nowak, S

    2016-09-29

    The changes in electrolyte composition on the molecular level and the reaction mechanisms of electrolyte degradation upon thermal aging are monitored by quantitative NMR spectroscopy, revealing similar rates of degradation for pristine and already aged electrolytes. The data analysis is not in favor of an autocatalytic reaction mechanism based on OPF3 but rather indicates that the degradation of LiPF6 in carbonate based solvents proceeds via a complex sequence of "linear" reactions rather than a cyclic reaction pattern which is determined by the amount of water present in the samples. All investigated electrolytes are reasonably stable at temperatures of up to 60 °C in the presence of minor amounts or absence of water hence indicating that chemical instability of electrolyte components against water is decisive for degradation and an increase in temperature ("thermal aging") just accelerates the degradation impact of water.

  12. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

    DEFF Research Database (Denmark)

    2001-01-01

    A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes....... With the thermally resistant polymer, e.g., polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled with an acid doped solid...

  13. A metered intake of milk following exercise and thermal dehydration restores whole-body net fluid balance better than a carbohydrate-electrolyte solution or water in healthy young men.

    Science.gov (United States)

    Seery, Suzanne; Jakeman, Philip

    2016-09-01

    Appropriate rehydration and nutrient intake in recovery is a key component of exercise performance. This study investigated whether the recovery of body net fluid balance (NFB) following exercise and thermal dehydration to -2 % of body mass (BM) was enhanced by a metered rate of ingestion of milk (M) compared with a carbohydrate-electrolyte solution (CE) or water (W). In randomised order, seven active men (aged 26·2 (sd 6·1) years) undertook exercise and thermal dehydration to -2 % of BM on three occasions. A metered replacement volume of M, CE or W equivalent to 150 % of the BM loss was then consumed within 2-3 h. NFB was subsequently measured for 5 h from commencement of rehydration. A higher overall NFB in M than CE (P=0·001) and W (P=0·006) was observed, with no difference between CE and W (P=0·69). After 5 h, NFB in M remained positive (+117 (sd 122) ml) compared with basal, and it was greater than W (-539 (sd 390) ml, P=0·011) but not CE (-381 (sd 460) ml, P=0·077, d=1·6). Plasma osmolality (Posm) and K remained elevated above basal in M compared with CE and W. The change in Posm was associated with circulating pre-provasopressin (r s 0·348, Pdehydration.

  14. Electrolytes and thermoregulation

    Science.gov (United States)

    Nielsen, B.; Greenleaf, J. E.

    1977-01-01

    The influence of ions on temperature is studied for cases where the changes in ionic concentrations are induced by direct infusion or injection of electrolyte solutions into the cerebral ventricles or into specific areas of brain tissue; intravenous infusion or injection; eating food or drinking solutions of different ionic composition; and heat or exercise dehydration. It is shown that introduction of Na(+) and Ca(++) into the cerebral ventricles or into the venous system affects temperature regulation. It appears that the specific action of these ions is different from their osmotic effects. It is unlikely that their action is localized to the thermoregulatory centers in the brain. The infusion experiments demonstrate that the changes in sodium balance occurring during exercise and heat stress are large enough to affect sweat gland function and vasomotor activity.

  15. Effect of Vitamin A, Vitamin C, Vitamin E and Levamisole on performance of Broilers

    Directory of Open Access Journals (Sweden)

    A.B. Rajput

    2009-12-01

    Full Text Available One hundred and eighty (180 unsexed day-old, commercial broiler chicks were purchased from Venkateshwara Hatcheries Pvt. Ltd. These chicks were weighed individually and uniformly distributed as 30 chicks in each of six groups. Each group was divided into two replicates with 15 chicks in each. The birds were offered feed and water ad-libitum. The chicks were fed with starter mash which contained crude protein 22% and metabolizable energy 2918 Kcal / kg up to three weeks of age. For next 3 weeks i.e. from 4 to 6 weeks of age with finisher mash which containedcrude protein 20% and metabolizable energy 2966 Kcal/ kg.Group T0 (control group was fed standard broiler mash. In group T1 Vitamin A was added @ 8500 IU/ litre of Drinking water. Group T2 was fed Broiler mash + Vitamin C @ 500 mg/ kg of feed. Group T3 was fed Broiler mash + Vitamin E @ 300 mg/ kg of feed. Group T4 was given Broiler mash + Levamisole @ 2 gm/ kg of feed and group. T5 was provided with the combination of all the feed supplements Vitamin A added @ 8500 IU/ litre of Drinking water, Broiler mash + Vitamin C @ 500 mg/ kg of feed + Vitamin E @ 300 mg/ kg of feed + Levamisole @ 2 gm /kg of feed.The results of economics of broiler production showed that net cost of production per bird was maximum for T5 (Rs.76.78 followed by T4 (Rs. 67.34, T1 (Rs. 66.56, T0 (Rs. 59.11,T2 (Rs. 58.16 and T3 (Rs. 58.02. The net profit per bird for groups T0, T1, T2, T3, T4 and T5 was Rs. 28.44, 21.49, 30.59, 30.48, 20.41and 11.12, respectively. The supplemented groups T2 and T3 have more net profit than control group. However, group T1, T4 and T5 had less net profit than the control group. [Vet World 2009; 2(6.000: 225-227

  16. [Biological role and importance in the skin metabolism of vitamin C].

    Science.gov (United States)

    Kleszczewska, Ewa

    2007-12-01

    Vitamins are a group of compounds indispensable for the development, normal growth and functioning of the human body. Lack of vitamins causes serious diseases for human, even though small amounts of them are required to maintain good health. Therefore there is growing interest conceding the role of vitamin C in biochemical-physiological conditions. This article reviews the role of water--soluble vitamin C in metabolic processes and discusses criteria used for recommended ingestion and presents recommendations for vitamin C intake. In the paper is discussed in detail the influence of level vitamin C (physico-chemical aspects) on the metabolism in skin.

  17. Vitamin K: an old vitamin in a new perspective

    OpenAIRE

    Gröber, U; Reichrath, J.; Holick, MF; Kisters, K

    2015-01-01

    The topic of “Vitamin K” is currently booming on the health products market. Vitamin K is known to be important for blood coagulation. Current research increasingly indicates that the antihaemorrhagic vitamin has a considerable benefit in the prevention and treatment of bone and vascular disease. Vitamin K1 (phylloquinone) is more abundant in foods but less bioactive than the vitamin K2 menaquinones (especially MK-7, menaquinone-7). Vitamin K compounds undergo oxidation-reduction cycling with...

  18. On electrochemical devices using alkaline polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, L. [Wuhan Univ., Wuhan (China). Dept. of Chemistry

    2010-07-01

    Solid polymer electrolytes (SPEs) enable a compact assembly of fuel cells and electrolyzers, thereby increasing the space-specific conversion efficiency and avoiding electrolyte leakage. The most widely used SPE in proton exchange membrane fuel cells (PEMFC) and chloro-alkali electrolyzers is Nafion. However, this strongly acidic polyelectrolyte allows only noble metals to be used as the catalysts in the electrochemical devices, which poses a problem in terms of price and resource limits. In principle, alkaline polymer electrolytes (APEs) should be used to eliminate the dependence on noble metal catalysts. The general structure of alkaline polymer electrolytes is a positively charged polymer, notably, a polymer chain attached with fixed cations such as quaternary ammonia group, and dissociated anion, OH-, to act as the charge carrier. This presentation described the challenges of developing APEs in terms of the chemical stability of quaternary ammonia group, the mobility of OH-, and high ionic concentration. The authors have been working on developing high-performance APEs since 2001. The most recent APEs were quaternary ammonia polysulfone (QAPS), which were found to be suitable for fuel cell and electrolyzer applications. The ionic conductivity was high and the crosslinked membrane had excellent mechanical strength, enabling operation at 90 degrees C. Non-precious metal catalysts were used in the APEs. For APE-based fuel cells (APEFC), chromium decorated nickel was used as the anode catalyst for hydrogen oxidation, and silver was used as the cathode catalyst for oxygen reduction. The preliminary performance of such an APEFC with non-Pt catalysts was found to be much better than that of traditional water electrolyzers using KOH solutions. 2 refs.

  19. Photopolymerized Electrolytes For Electrochromic Devices

    Science.gov (United States)

    Cogan, Stuart; Rauh, R. David

    1994-01-01

    Thin ion-conducting electrolyte films for use in electrochromic devices now fabricated relatively easily and quickly with any of class of improved formulations containing ultraviolet-polymerizable components. Formulations are liquids in their monomeric forms and self-supporting, transparent solids in their polymeric forms. Thin solid electrolytes form quickly and easily between electrode-bearing substrates. Film thus polymerized acts not only as solid electrolyte but also as glue holding laminate together: feature simplifies fabrication by reducing need for sealants and additional mechanical supports.

  20. Organic electrolytes for sodium batteries

    Science.gov (United States)

    Vestergaard, B.

    1992-09-01

    A summary of earlier given status reports in connection with the project on organic electrolytes for sodium batteries is presented. The aim of the investigations was to develop new room temperature molten salts electrolytes mainly with radical substituted heterocyclic organic chlorides mixed with aluminum chloride. The new electrolytes should have an ionic conductivity comparable with MEIC1:AlCl3 or better. A computer model program MOPAC (Molecular Orbital Package) was to be included to calculate theoretically reduction potentials for a variety of organic cations. Furthermore, MOPAC could be utilized to predict the electron densities, and then give a prediction of the stability of the organic cation.

  1. Solid-polymer-electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, T.F.

    1992-07-01

    A transport model for polymer electrolytes is presented, based on concentrated solution theory and irreversible thermodynamics. Thermodynamic driving forces are developed, transport properties are identified and experiments devised. Transport number of water in Nafion 117 membrane is determined using a concentration cell. It is 1.4 for a membrane equilibrated with saturated water vapor at 25{degrees}C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the water content approaches zero. The relation between transference number, transport number, and electroosmotic drag coefficient is presented, and their relevance to water-management is discussed. A mathematical model of transport in a solid-polymer-electrolyte fuel cell is presented. A two-dimensional membrane-electrode assembly is considered. Water management, thermal management, and utilization of fuel are examined in detail. The membrane separators of these fuel cells require sorbed water to maintain conductivity; therefore it is necessary to manage the water content in membranes to ensure efficient operation. Water and thermal management are interrelated. Rate of heat removal is shown to be a critical parameter in the operation of these fuel cells. Current-voltage curves are presented for operation on air and reformed methanol. Equations for convective diffusion to a rotating disk are solved numerically for a consolute point between the bulk concentration and the surface. A singular-perturbation expansion is presented for the condition where the bulk concentration is nearly equal to the consolute-point composition. Results are compared to Levich's solution and analysis.

  2. Solid-polymer-electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Thomas F. [Univ. of California, Berkeley, CA (United States)

    1992-07-01

    A transport model for polymer electrolytes is presented, based on concentrated solution theory and irreversible thermodynamics. Thermodynamic driving forces are developed, transport properties are identified and experiments devised. Transport number of water in Nafion 117 membrane is determined using a concentration cell. It is 1.4 for a membrane equilibrated with saturated water vapor at 25°C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the water content approaches zero. The relation between transference number, transport number, and electroosmotic drag coefficient is presented, and their relevance to water-management is discussed. A mathematical model of transport in a solid-polymer-electrolyte fuel cell is presented. A two-dimensional membrane-electrode assembly is considered. Water management, thermal management, and utilization of fuel are examined in detail. The membrane separators of these fuel cells require sorbed water to maintain conductivity; therefore it is necessary to manage the water content in membranes to ensure efficient operation. Water and thermal management are interrelated. Rate of heat removal is shown to be a critical parameter in the operation of these fuel cells. Current-voltage curves are presented for operation on air and reformed methanol. Equations for convective diffusion to a rotating disk are solved numerically for a consolute point between the bulk concentration and the surface. A singular-perturbation expansion is presented for the condition where the bulk concentration is nearly equal to the consolute-point composition. Results are compared to Levich`s solution and analysis.

  3. An electrolyte CPA equation of state for mixed solvent electrolytes

    DEFF Research Database (Denmark)

    Maribo-Mogensen, Bjørn; Thomsen, Kaj; Kontogeorgis, Georgios M.

    2015-01-01

    that the predictive capabilities could be improved through the development of an electrolyte equation of state. In this work, the Cubic Plus Association (CPA) Equation of State is extended to handle mixtures containing electrolytes by including the electrostatic contributions from the Debye-Hückel and Born terms...... depression. Finally, the model is applied to predict VLE, LLE, and SLE in aqueous salt mixtures as well as in mixed solvents....

  4. Vitamine K

    Directory of Open Access Journals (Sweden)

    Bal dit Sollier Claire

    2011-03-01

    Full Text Available Subclasses of vitamin K, their origins, their differential characteristics of absorption and metabolism, their relative effects on gammacarboxylation of various proteins implicated in hemostasis andcoagulation, in bone calcification are not well known even by experts in these fields. These misunderstandings explain errors in recommendations for public and for patients. This review will not expose again the fundamentals on vitamins K as presented in the paper by Marc Guillaumont published in 2000 in this same journal. This 2011 review will try to update our actual knowledge and most of all will insist on their practical implications especially on the management of oral anticoagulant treatments since until recently vitamin K antagonist was the only available type of such a treatment. Several examples illustrate the need for a better understanding of this subject. The fear that diet vitamin K could deregulate the equilibrium of oral vitamin K antagonist treatment leads to recommend a quite total suppression of vitamin K containing components in the diet of anticoagulated patients. This leads to an opposite effect: a high sensitivity to vitamin K and to disequilibrium of the anticoagulant treatment while a comprehensivemoderate and regular diet intake of vitamin K first facilitates the food choice of the patients but also helps to stabilise the treatment of chronically anticoagulated patients. Vitamin K plays a role in bone calcification and in osteoporosis prevention. Until recently the food supplementation with vitamin K in view of preventing osteoporosis in general population was strongly limited due to fear to affect the treatment equilibrium in anticoagulated patients. While an understanding that the effects of moderate supplementation in vitamin K has no or limited effect on anticoagulation and on the long run could at the opposite help to stabilize the daily level of anticoagulation in patients chronically treated with vitamin K.

  5. Vitamin D and Disease Prevention

    Science.gov (United States)

    ... a hormone. The skin makes vitamin D after exposure to sunlight. We also absorb vitamin D from certain foods, ... people do not make enough vitamin D by exposure to sunlight* or get enough through their diets. They may ...

  6. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... fiber, magnesium, and vitamin E (for children and adolescents) vitamin B-12, iron, folic acid, and vitamins ... manufacturers evaluate their products through testing identity, purity, strength, and composition. back to ... Federal, State & Local Officials ...

  7. Vitamin A and Bone Health

    Science.gov (United States)

    ... supported by your browser. Home Bone Basics Nutrition Vitamin A and Bone Health Publication available in: PDF ( ... Find More Information? For Your Information What Is Vitamin A? Vitamin A is a family of compounds ...

  8. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... and the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12 and ... into the body with the use of bile acids, which are fluids used to absorb fat. The ...

  9. PVDF-HFP-based porous polymer electrolyte membranes for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Ruiying; Liu, Bowen; Zhu, Zhongzheng; Liu, Yun; Li, Jianling; Wang, Xindong [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Li, Qingfeng [Department of Chemistry, Technology University of Denmark, DK-2800 Lyngby (Denmark)

    2008-10-01

    As a potential electrolyte for lithium-ion batteries, a porous polymer electrolyte membrane based on poly(vinylidenefluoride-hexafluoropropylene) (PVDF-HFP) was prepared by a phase inversion method. The casting solution, effects of the solvent and non-solvent and addition of micron scale TiO{sub 2} particles were investigated. The membranes were characterized by SEM, XRD, AC impedance, and charge/discharge tests. By using acetone as the solvent and water as the non-solvent, the prepared membranes showed good ability to absorb and retain the lithium ion containing electrolyte. Addition of micron TiO{sub 2} particles to the polymer electrolyte was found to enhance the tensile strength, electrolyte uptake, ion conductivity and the electrolyte/electrode interfacial stability of the membrane. (author)

  10. Radio-frequency capacitive discharge with non-flow-type and droplet-jet electrolytic electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Gaisin, A. F., E-mail: LShGasimova@kai.ru [Kazan Tupolev National Research Technical University (Russian Federation); Abdullin, I. Sh., E-mail: almaz87@mail.ru [Kazan National Research Technological University (Russian Federation); Basyrov, R. Sh.; Khaziev, R. M.; Samitova, G. T.; Shakirova, E. F. [Kazan Tupolev National Research Technical University (Russian Federation)

    2014-12-15

    Results are presented from experimental studies of the shape, structure, and spectral characteristics of an RF capacitive discharge operating between a droplet-jet electrolytic electrode and an electrolytic cell in air at pressures of P = 10{sup 3}–10{sup 5} Pa, as well as of a discharge burning between a copper rod and the surface of non-flow electrolyte at atmospheric pressure. It is found that, at voltages of U ≥ 3500 V, the multichannel discharge burning between the rod and the electrolyte (saturated solution of NaCl in technical water) surface transforms into a torch discharge. Specific features of the burning of a discharge with a droplet electrolytic electrode are investigated. Different forms of discharges burning on the surface of a copper tube and an electrolyte jet are revealed.

  11. Vitamin E in dermatology

    Science.gov (United States)

    Keen, Mohammad Abid; Hassan, Iffat

    2016-01-01

    Vitamin E is an important fat-soluble antioxidant and has been in use for more than 50 years in dermatology. It is an important ingredient in many cosmetic products. It protects the skin from various deleterious effects due to solar radiation by acting as a free-radical scavenger. Experimental studies suggest that vitamin E has antitumorigenic and photoprotective properties. There is a paucity of controlled clinical studies providing a rationale for well-defined dosages and clinical indications of vitamin E usage in dermatological practice. The aim of this article is to review the cosmetic as well as clinical implications of vitamin E in dermatology. PMID:27559512

  12. Vitamin D-mangel

    DEFF Research Database (Denmark)

    Hey, Henrik; Schmedes, Anne; Horn, Peer

    2009-01-01

    The importance of vitamin D for osteoporosis and fractures has been known for more than 40 years. Vitamin D deficiency is diagnosed by measuring 25-hydroxyvitamin D (25-OHD), which should be > 50 nmol/l year round. Recent research suggests that a number of severe diseases could be prevented...... by increasing 25-OHD to 80 nmol/l. Despite a strong focus on such increase, recommendations for intake of Vitamin D have not been changed and the present recommendations are too low even to ensure > 50 nmol/l. To achieve optimal concentrations > 80 nmol/l, we estimate that 50-70 microgram of vitamin D per day...

  13. HYDROSOLUBLE VITAMINS AND SPORT

    Directory of Open Access Journals (Sweden)

    Vladmila Bojanić

    2011-06-01

    Full Text Available Vitamins are organic substances needed for normal cell functioning in the human body, and therefore human health. People who train sports require an optimal psychophysical performance in order to achieve the best sports results. Athletes’ needs for vitamins may be higher than in general population, also they are taking vitamin supplements more often than other people. Thus, it is very important for them to be familiar with the vitamins’ roles and recommended intake levels.Hydrosoluble vitamins are easily absorbed into the blood and excreted in urine, and so very little stored in the body. They are less likely to cause toxic effects compared to the liposoluble vitamins, but their deficiency may occur much faster. The B group of vitamins takes part in many biochemical processes, and is especially important for athletes, as these vitamins help conversion of energy from food into the muscle energy. Vitamin C is known as an antioxidant that protects against oxygen free radicals. It has a number of other roles in metabolism of carbohydrates, fats, proteins and minerals.Athletes are likely to intake sufficient quantities of vitamins through the nutrition. Vitamins’ supplements are usually unnecessary and without additional benefits on sports performance. However, if vitamins’ supplements are taken, attention must be paid for their tolerable upper intake levels.

  14. Non-aqueous electrolytes for electrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhengcheng; Dong, Jian; Amine, Khalil

    2016-06-14

    An electrolyte electrochemical device includes an anodic material and an electrolyte, the electrolyte including an organosilicon solvent, a salt, and a hybrid additiving having a first and a second compound, the hybrid additive configured to form a solid electrolyte interphase film on the anodic material upon application of a potential to the electrochemical device.

  15. Lithium sulfur batteries and electrolytes and sulfur cathodes thereof

    Energy Technology Data Exchange (ETDEWEB)

    Visco, Steven J.; Goncharenko, Nikolay; Nimon, Vitaliy; Petrov, Alexei; Nimon, Yevgeniy S.; De Jonghe, Lutgard C.; Katz, Bruce D.; Loginova, Valentina

    2017-05-23

    Lithium sulfur battery cells that use water as an electrolyte solvent provide significant cost reductions. Electrolytes for the battery cells may include water solvent for maintaining electroactive sulfur species in solution during cell discharge and a sufficient amount of a cycle life-enhancing compound that facilitates charging at the cathode. The combination of these two components enhances one or more of the following cell attributes: energy density, power density and cycle life. For instance, in applications where cost per Watt-Hour (Wh) is paramount, such as grid storage and traction applications, the use of an aqueous electrolyte in combination with inexpensive sulfur as the cathode active material can be a key enabler for the utility and automotive industries, for example, providing a cost effective and compact solution for load leveling, electric vehicles and renewable energy storage. Sulfur cathodes, and methods of fabricating lithium sulfur cells, in particular for loading lithium sulfide into the cathode structures, provide further advantages.

  16. Composite solid polymer electrolyte membranes

    Energy Technology Data Exchange (ETDEWEB)

    Formato, Richard M. (Shrewsbury, MA); Kovar, Robert F. (Wrentham, MA); Osenar, Paul (Watertown, MA); Landrau, Nelson (Marlborough, MA); Rubin, Leslie S. (Newton, MA)

    2001-06-19

    The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.

  17. Vitamin K during infancy: current status and recommendations.

    Science.gov (United States)

    Singh, M

    1997-08-01

    Vitamin K is needed to synthesize coagulation factors II (prothrombin), VII, IX, and X through the carboxylation of glutamic acid in vitamin K-dependent proteins which results in the creation of effective calcium binding sites which, in turn, facilitates the coagulation process. Vitamin K exists as naturally occurring vitamin K-I (phylloquinone) in green leafy vegetables and vegetable oils, vitamin K-II (menaquinone) as produced in the gut by bacteroides fragilis and E. coli, and synthetic vitamin K-III (menadoine sodium bisulfite) which is water-soluble and capable of producing serious jaundice in newborns, especially those with instability of glutathione and deficiency of G6PD. Humans require about 5 mcg of vitamin K daily. Since it is indigenously produced in the gut by bacterial flora, dietary deficiency of vitamin K in healthy subjects is rare. Vitamin K is usually the first vitamin given at birth. Newborn babies, however, absorb only approximately 30% of ingested vitamin K, compared to 50-70% in adults. Hemorrhagic disease is a manifestation of vitamin K deficiency in newborn infants. Hemorrhagic disease of the newborn (HDN), early HDN, classical HDN, and late HDN are discussed. The American Academy of Pediatrics recommended in 1961 that all healthy term newborn babies receive 0.5-1.0 mg of vitamin K-I intramuscularly at birth. However, while the authors have not followed those recommendations in their neonatal unit for 15 years, they have experienced only a 0.1% incidence of classical HDN. High-risk newborns at the unit are routinely given the recommended dose of K-I at birth.

  18. Vitamin E plasma concentration in osteoporotic patients

    Directory of Open Access Journals (Sweden)

    Hajimahmoodi M

    2007-06-01

    Full Text Available Background: The cause of osteoporosis is multifactorial and many dietary factors are important in the prevention of this disease. Antioxidants as free radical scavengers may influence osteoporosis by reducing the effects of oxidative stress that may be associated with bone loss. Vitamin E is an important antioxidant that protects polyunsaturated fatty acids (PUFA in cell membranes from oxidation. There are only two studies regarding vitamin E plasma levels in subjects suffering from osteoporosis. The purpose of this study was to investigate the association between plasma vitamin E levels and bone mineral density (BMD in Iranian patients. Methods: Subjects were consecutively recruited between May and September 2005 from among a total of approximately 1000 people referred for instrumental screening for osteoporosis to the Jami Clinic in Tehran. Inclusion criteria for the study group were: a femoral neck T-score of -1 or less, osteopenia, severe osteopenia and osteoporosis. A total of 137 subjects were enrolled. According to their femoral and spinal BMD scores, 54 persons were selected as a control group. The control group consisted of subjects with a femoral neck T-score and spine T-score of -1 or more. In selecting the case group, only the femoral BMD score was used. Plasma vitamin E was measured, after extraction with methanol, by HPLC with UV detection at 280 nm. Methanol, deionized water and butanol (90:4:6 was used as a mobile phase with a C8 column. The flow rate was 1.0 ml. min-1 and the acetate ester of vitamin E was used as an internal standard. Results: The results show no significant difference in plasma vitamin E between the control and case groups, however linear regression analysis does reveal a significant difference between the T-score and plasma vitamin E. Conclusion: Deceleration Femoral bone Density during osteoporosis will be Accelerated with Decrease of Vitamin E Antioxidant level.

  19. Sunlight and Vitamin D

    Science.gov (United States)

    Wacker, Matthias; Holick, Michael F.

    2013-01-01

    Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3. Previtamin D3 and vitamin D3 also absorb UV B radiation and are converted into a variety of photoproducts some of which have unique biologic properties. Sun induced vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D which is a major circulating form and 1,25-dihydroxyvitamin D which is the biologically active form respectively. 1,25-dihydroxyvitamin D plays an important role in regulating calcium and phosphate metabolism for maintenance of metabolic functions and for skeletal health. Most cells and organs in the body have a vitamin D receptor and many cells and organs are able to produce 1,25-dihydroxyvitamin D. As a result 1,25-dihydroxyvitamin D influences a large number of biologic pathways which may help explain association studies relating vitamin D deficiency and living at higher latitudes with increased risk for many chronic diseases including autoimmune diseases, some cancers, cardiovascular disease, infectious disease, schizophrenia and type 2 diabetes. A three-part strategy of increasing food fortification programs with vitamin D, sensible sun exposure recommendations and encouraging ingestion of a vitamin D supplement when needed should be implemented to prevent global vitamin D deficiency and its negative health consequences. PMID:24494042

  20. Vitamin E Nicotinate

    Science.gov (United States)

    Duncan, Kimbell R.; Suzuki, Yuichiro J.

    2017-01-01

    Vitamin E refers to a family of compounds that function as lipid-soluble antioxidants capable of preventing lipid peroxidation. Naturally occurring forms of vitamin E include tocopherols and tocotrienols. Vitamin E in dietary supplements and fortified foods is often an esterified form of α-tocopherol, the most common esters being acetate and succinate. The vitamin E esters are hydrolyzed and converted into free α-tocopherol prior to absorption in the intestinal tract. Because its functions are relevant to many chronic diseases, vitamin E has been extensively studied in respect to a variety of diseases as well as cosmetic applications. The forms of vitamin E most studied are natural α-tocopherol and the esters α-tocopheryl acetate and α-tocopheryl succinate. A small number of studies include or focus on another ester form, α-tocopheryl nicotinate, an ester of vitamin E and niacin. Some of these studies raise the possibility of differences in metabolism and in efficacy between vitamin E nicotinate and other forms of vitamin E. Recently, through metabolomics studies, we identified that α-tocopheryl nicotinate occurs endogenously in the heart and that its level is dramatically decreased in heart failure, indicating the possible biological importance of this vitamin E ester. Since knowledge about vitamin E nicotinate is not readily available in the literature, the purpose of this review is to summarize and evaluate published reports, specifically with respect to α-tocopheryl nicotinate with an emphasis on the differences from natural α-tocopherol or α-tocopheryl acetate. PMID:28335380

  1. Vitamin E Nicotinate

    Directory of Open Access Journals (Sweden)

    Kimbell R. Duncan

    2017-03-01

    Full Text Available Vitamin E refers to a family of compounds that function as lipid-soluble antioxidants capable of preventing lipid peroxidation. Naturally occurring forms of vitamin E include tocopherols and tocotrienols. Vitamin E in dietary supplements and fortified foods is often an esterified form of α-tocopherol, the most common esters being acetate and succinate. The vitamin E esters are hydrolyzed and converted into free α-tocopherol prior to absorption in the intestinal tract. Because its functions are relevant to many chronic diseases, vitamin E has been extensively studied in respect to a variety of diseases as well as cosmetic applications. The forms of vitamin E most studied are natural α-tocopherol and the esters α-tocopheryl acetate and α-tocopheryl succinate. A small number of studies include or focus on another ester form, α-tocopheryl nicotinate, an ester of vitamin E and niacin. Some of these studies raise the possibility of differences in metabolism and in efficacy between vitamin E nicotinate and other forms of vitamin E. Recently, through metabolomics studies, we identified that α-tocopheryl nicotinate occurs endogenously in the heart and that its level is dramatically decreased in heart failure, indicating the possible biological importance of this vitamin E ester. Since knowledge about vitamin E nicotinate is not readily available in the literature, the purpose of this review is to summarize and evaluate published reports, specifically with respect to α-tocopheryl nicotinate with an emphasis on the differences from natural α-tocopherol or α-tocopheryl acetate.

  2. Vitamin E Nicotinate.

    Science.gov (United States)

    Duncan, Kimbell R; Suzuki, Yuichiro J

    2017-03-13

    Vitamin E refers to a family of compounds that function as lipid-soluble antioxidants capable of preventing lipid peroxidation. Naturally occurring forms of vitamin E include tocopherols and tocotrienols. Vitamin E in dietary supplements and fortified foods is often an esterified form of α-tocopherol, the most common esters being acetate and succinate. The vitamin E esters are hydrolyzed and converted into free α-tocopherol prior to absorption in the intestinal tract. Because its functions are relevant to many chronic diseases, vitamin E has been extensively studied in respect to a variety of diseases as well as cosmetic applications. The forms of vitamin E most studied are natural α-tocopherol and the esters α-tocopheryl acetate and α-tocopheryl succinate. A small number of studies include or focus on another ester form, α-tocopheryl nicotinate, an ester of vitamin E and niacin. Some of these studies raise the possibility of differences in metabolism and in efficacy between vitamin E nicotinate and other forms of vitamin E. Recently, through metabolomics studies, we identified that α-tocopheryl nicotinate occurs endogenously in the heart and that its level is dramatically decreased in heart failure, indicating the possible biological importance of this vitamin E ester. Since knowledge about vitamin E nicotinate is not readily available in the literature, the purpose of this review is to summarize and evaluate published reports, specifically with respect to α-tocopheryl nicotinate with an emphasis on the differences from natural α-tocopherol or α-tocopheryl acetate.

  3. B-group vitamin production by lactic acid bacteria--current knowledge and potential applications.

    Science.gov (United States)

    LeBlanc, J G; Laiño, J E; del Valle, M Juarez; Vannini, V; van Sinderen, D; Taranto, M P; de Valdez, G Font; de Giori, G Savoy; Sesma, F

    2011-12-01

    Although most vitamins are present in a variety of foods, human vitamin deficiencies still occur in many countries, mainly because of malnutrition not only as a result of insufficient food intake but also because of unbalanced diets. Even though most lactic acid bacteria (LAB) are auxotrophic for several vitamins, it is now known that certain strains have the capability to synthesize water-soluble vitamins such as those included in the B-group (folates, riboflavin and vitamin B(12) amongst others). This review article will show the current knowledge of vitamin biosynthesis by LAB and show how the proper selection of starter cultures and probiotic strains could be useful in preventing clinical and subclinical vitamin deficiencies. Here, several examples will be presented where vitamin-producing LAB led to the elaboration of novel fermented foods with increased and bioavailable vitamins. In addition, the use of genetic engineering strategies to increase vitamin production or to create novel vitamin-producing strains will also be discussed. This review will show that the use of vitamin-producing LAB could be a cost-effective alternative to current vitamin fortification programmes and be useful in the elaboration of novel vitamin-enriched products. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  4. Synthesis and evaluation of chitosan-Vitamin C complex

    Directory of Open Access Journals (Sweden)

    Tian X

    2009-01-01

    Full Text Available Chitosan is a biocompatible, biodegradable and non-toxic polysaccharide polymer. It dissolves in water only if the pH is lower than 6.5. To extend its range of application, many water-soluble derivatives have therefore been prepared. In this research, chitosan-vitamin C complex was synthesized and characterized with Fourier transformed infrared spectroscopy, differential scanning calorimetry and 1 H-NMR. The solubility of chitosan-vitamin C complex in distilled water was greatly improved. The ·O2 - scavenging activity of chitosan-vitamin C complex was compared with chitosan and vitamin C by measuring the auto-oxidation rate of pyrogallic acid. Results showed that the scavenging activity on ·O2 - by chitosan-vitamin C complex was stronger than that by CS. At low concentrations (< 0.05 mg/ml, the scavenging activity of chitosan-vitamin C complex was stronger than that of vitamin C, but after certain concentrations (>0.1mg/ml, its scavenging activity was lower than that of vitamin C.

  5. Urinary levels of early kidney injury molecules in children with vitamin B12 deficiency.

    Science.gov (United States)

    Güneş, Ali; Aktar, Fesih; Tan, İlhan; Söker, Murat; Uluca, Ünal; Balık, Hasan; Mete, Nuriye

    2016-10-01

    The aim of this study was to investigate urine early kidney injury molecules, including human kidney injury molecule-1 (KIM-1), liver-type fatty-acid binding protein (L-FABP), N-acetyl-b-D-glucosaminidase A (NAG), and neutrophil gelatinase-associated lipocalin (NGAL) in children with vitamin B12 (cobalamin) deficiency (CD). Twelve children with vitamin B12 deficiency and 20 healthy matched controls were included. Hematologic parameters, serum urea, creatinine (Cr), electrolytes, B12 and folate levels were recorded. Estimated glomerular filtration rate (eGFR) was calculated. Urine protein, electrolytes, andurinary early markers were measured. Patients with CD had significantly higher urine electrolyte/Cr ratios (p B12 and urinary markers in the patients (p B12 deficiency suggest a possible subclinical renal dysfunction, which cannot be determined by conventional kidney function tests.

  6. Vitamin D Deficiency

    Science.gov (United States)

    ... body forms vitamin D naturally after exposure to sunlight. But too much sun exposure can lead to skin aging and skin cancer, ... a malabsorption problem) You don't get enough exposure to sunlight. Your liver or kidneys cannot convert vitamin D ...

  7. Riboflavin : A multifunctional vitamin.

    NARCIS (Netherlands)

    de Souza, ACS; Ferreira, CV; Juca, MB; Aoyama, H; Cavagis, ADM; Peppelenbosch, MP

    2005-01-01

    Riboflavin, a component of the B-2 vitaminic complex, plays important roles in biochemistry, especially in redox reactions, due to the ability to participate in both one- and two-electron transfers as well as acting as a photosensitizer. Accordingly, low intakes of this vitamin have been associated

  8. Vitamin D Deficiency

    Science.gov (United States)

    ... and the foods you eat. Foods with natural vitamin D include: • Certain fish: salmon, sardines, mackerel, tuna • Cod liver oil • Shiitake mushrooms • Egg yolks Foods that often have added vitamin D include: • Dairy products • Orange juice • Infant formula • ...

  9. Vitamins and Minerals

    Science.gov (United States)

    ... you don't eat meat, you can find vitamin B12 in eggs, milk and other dairy foods, and fortified breakfast cereals. Vegans (vegetarians who eat no animal products at all, including dairy products) may need to take vitamin supplements. If you're thinking about becoming a ...

  10. Vitamin D and Cancer

    Science.gov (United States)

    Vuolo, Laura; Di Somma, Carolina; Faggiano, Antongiulio; Colao, Annamaria

    2012-01-01

    Vitamin D system is a complex pathway that includes precursors, active metabolites, enzymes, and receptors. This complex system actives several molecular pathways and mediates a multitude of functions. In addition to the classical role in calcium and bone homeostasis, vitamin D plays “non-calcemic” effects in host defense, inflammation, immunity, and cancer processes as recognized in vitro and in vivo studies. The aim of this review is to highlight the relationship between vitamin D and cancer, summarizing several mechanisms proposed to explain the potential protective effect of vitamin D against the development and progression of cancer. Vitamin D acts like a transcription factor that influences central mechanisms of tumorigenesis: growth, cell differentiation, and apoptosis. In addition to cellular and molecular studies, epidemiological surveys have shown that sunlight exposure and consequent increased circulating levels of vitamin D are associated with reduced reduced occurrence and a reduced mortality in different histological types of cancer. Another recent field of interest concerns polymorphisms of vitamin D receptor (VDR); in this context, preliminary data suggest that VDR polymorphisms more frequently associated with tumorigenesis are Fok1, Bsm1, Taq1, Apa1, EcoRV, Cdx2; although further studies are needed to clarify their role in the cancer. In this review, the relationship between vitamin D and cancer is discussed. PMID:22649423

  11. Vitamin B12 deficiency

    Science.gov (United States)

    Vitamin B12 (B12; also known as cobalamin) is a B vitamin that has an important role in cellular metabolism, especially in DNA synthesis, methylation and mitochondrial metabolism. Clinical B12 deficiency with classic haematological and neurological manifestations is relatively uncommon. However, sub...

  12. Riboflavin : A multifunctional vitamin.

    NARCIS (Netherlands)

    de Souza, ACS; Ferreira, CV; Juca, MB; Aoyama, H; Cavagis, ADM; Peppelenbosch, MP

    2005-01-01

    Riboflavin, a component of the B-2 vitaminic complex, plays important roles in biochemistry, especially in redox reactions, due to the ability to participate in both one- and two-electron transfers as well as acting as a photosensitizer. Accordingly, low intakes of this vitamin have been associated

  13. 高效液相色谱法同时测定食品中9种水溶性维生素%Simultaneous determination of nine water-soluble vitamins in foods by high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    任丹丹; 谢云峰; 刘佳佳; 李月琪; 杨永坛

    2014-01-01

    Objective To develop a high performance liquid chromatography (HPLC) method for the de-termination of nine water-soluble vitamins in foods. Methods The chromatographic separation was per-formed on a C18 column with gradient elution, using potassium dihydrogen phosphate and acetonitrile as mobile phase. The analyte was detected by HPLC with diode array detector. Results Under the optimal conditions, the calibration curves of nine vitamins were linear in the range of 0.04~100 μg/mL for vitamin C, 0.02~100μg/mL for thiamine, riboflavin, nicotinamide and pyridoxine;0.08~400μg/mL for pantothenic acid;0.08~200μg/mL for biotin; 0.01~50 μg/mL for folic acid; and 0.04~100 μg/mL for cyanocobalamin with correlation coefficient (r) more than 0.9997. The relative standard deviations (RSDs) were less than 1.35%, and the limit of detection (LOD) was found in the range of 3~45 ng/mL and the spiked recoveries were between 90.6~105.4%. The developed method was applied to determine the water-soluble vitamins in functional beverages, multivita-min tablets and fortified rice. Conclusion The proposed method is rapid, accurate and sensitive, and it is suitable for detecting water-soluble vitamins in fortified foods.%目的:建立同时测定食品中9种水溶性维生素的高效液相色谱分析方法。方法采用C18色谱柱进行分离,以pH 2.5,25 mmol/L KH2PO4-乙腈二元体系为流动相进行梯度洗脱,最后用高效液相色谱二极管阵列检测器对9种维生素进行测定。结果在优化实验条件下,测得维生素C的线性范围为0.04~100μg/mL,硫胺、核黄素、烟酰胺和吡哆醇的线性范围为0.02~100μg/mL,泛酸的线性范围为0.08~400μg/mL,生物素的线性范围为0.08~200μg/mL,叶酸的线性范围为0.01~50μg/mL,氰钴胺的线性范围为0.04~100μg/mL;线性相关系数为0.9997~0.9999,相对标准偏差为0.28%~1.35%,检出限范围为3~45 ng/mL,加标回收率为90.6%~105.4%。结论该方法快速、准确、灵敏,

  14. Development and Characterization of Temperature-resistant Polymer Electrolytes

    DEFF Research Database (Denmark)

    Qingfeng, Li; Hjuler, Hans Aage; Bjerrum, Niels

    1999-01-01

    Acid-doped PBI polymer electrolyte membranes have been developed and characterized for fuel cell applications at temperatures up to 200°C. Electric conductivity as high as 0.13 S/cm is obtained at 160°C at high doping levels. The water osmotic drag coefficient of the polymer electrolyte is found...... to be virtually zero, which allows a fuel cell to operate with no external humidification. At operational temperatures up to 200°C, a fuel cell based on this polymer membrane exhibits promising performance....

  15. Water transport modeling of three dimensional polymer electrolyte membrane fuel cell%三维聚合物电解质膜燃料电池中水的输运模拟

    Institute of Scientific and Technical Information of China (English)

    Alhussan Khaled

    2008-01-01

    针对新型螺旋形加压聚合物电解质膜燃料电池,提出了一种液态水生成和输运效应的数值模型.该数值模型基于燃料电池的物理机理、流体流动、传热导、多孔介质中的传质、电化学反应、含相变的多相流动、电流输运、多孔介质和固体导电区域中的位势场以及穿过聚合物膜的水的输运设计优化过程.在分析中还使用了燃料电池模型.例如,电化学模型--用于预测局部电流密度和电压分布;位势场模型--用于预测多孔介质以及固体导电区中的电流和电压;多相混合物模型--用于预测在多孔扩散层中的液态水和气体流;薄膜多相模型--用于研究气体流道中的液态水流.最后给出了聚合物电解质膜燃料电池液态水生成和输运的理论模型的数值结果,包括催化层和膜中的H2,O2和H2O的质量和克分子数的等值线图.%A numerical modeling of liquid water formation and transport effects of a new spiral-shape design of pressurized polymer electrolyte membrane (PEM) fuel cell was proposed. Based on the physical principles of fuel cells, fluid flow, heat transfer, mass transfer in porous media, electrochemical reactions, multiphase flow with phase change, transport of current and potential field in porous media and solid conducting regions, and water transport across the polymer membrane, the optimal process was designed in this numberical modeling, and fuel cell models were used to do analysis. For example, an electrochemical model was used to predict local current density and voltage distributions, a potential field model was used to predict current and voltage in porous and solid conducting regions, a multiphase mixture model was used to predict liquid water and gas flow in the porous diffusion layers, and a thin film multiphase model was used to track liquid water flow in gas flow passages. The numerical results of the theoretical modeling of liquid water formation and transport

  16. Pantothenic acid (Vitamin B5)

    Science.gov (United States)

    ... vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B12 (cyanocobalamin), and folic acid. However, some products do ... Pantothenas, Calcium D-Pantothenate, Calcium Pantothenate, Complexe de Vitamines B, D-Calcium Pantothenate, D-Panthenol, D-Panthénol, ...

  17. Extended UNIQUAC Model for Correlation and Prediction of Vapor-Liquid-Liquid-Solid Equilibria in Aqueous Salt Systems Containing Non-Electrolytes. Part B. Alcohol (Ethanol, Propanols, Butanols) - Water-salt systems

    DEFF Research Database (Denmark)

    Thomsen, Kaj; Iliuta, Maria Cornelia; Rasmussen, Peter

    2004-01-01

    -Redlich-Kwong equation of state. The model only requires binary, temperature-dependent interaction parameters. It has previously been used to describe the excess Gibbs energy for aqueous electrolyte mixtures and aqueous electrolyte systems containing methanol. It has been found to be an adequate model for representing...... solid-liquid-vapor equilibrium and thermal property data for strongly non-ideal systems. In this work, the model is extended to aqueous salt systems containing higher alcohols. The calculations are based on an extensive database consisting of salt solubility data, vapor liquid equilibrium data...

  18. Development of high performance proton-conducting solid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Linkous, C.A.; Kopitzke, R.W. [Florida Solar Energy Center, Cocoa, FL (United States)

    1998-08-01

    This work seeks to improve the efficiency of fuel cell and electrolyzer operation by developing solid electrolytes that will function at higher temperatures. Two objectives were pursued: (1) determine the mechanism of hydrolytic decomposition of aromatic sulfonic acid ionomers, with the intent of identifying structural weaknesses that can be avoided in future materials; and (2) identify new directions in solid electrolyte development. After evaluating a number of aromatic sulfonates, it became apparent that no common mechanism was going to be found; instead, each polymer had its own sequence of degradation steps, involving some combination of desulfonation and/or chain scission. For electrochemical cell operation at temperatures > 200 C, it will be necessary to develop solid electrolytes that do not require sulfonic acids and do not require water to maintain its conductivity mechanism.

  19. Hydrogen production via urea electrolysis using a gel electrolyte

    Science.gov (United States)

    King, Rebecca L.; Botte, Gerardine G.

    2011-03-01

    A technology was demonstrated for the production of hydrogen and other valuable products (nitrogen and clean water) through the electrochemical oxidation of urea in alkaline media. In addition, this process remediates toxic nitrates and prevents gaseous ammonia emissions. Improvements to urea electrolysis were made through replacement of aqueous KOH electrolyte with a poly(acrylic acid) gel electrolyte. A small volume of poly(acrylic acid) gel electrolyte was used to accomplish the electrochemical oxidation of urea improving on the previous requirement for large amounts of aqueous potassium hydroxide. The effect of gel composition was investigated by varying polymer content and KOH concentrations within the polymer matrix in order to determine which is the most advantageous for the electrochemical oxidation of urea and production of hydrogen.

  20. Composition and recovery method for electrolytic manganese residue

    Institute of Scientific and Technical Information of China (English)

    陶长元; 李明艳; 刘作华; 杜军

    2009-01-01

    According to the statistic analysis,the reserve of manganese in electrolytic manganese residue deposit is over 780 kt. The average contents of available manganese and ammonium reach 3.90% and 1.68% (mass fraction),respectively. Large amount of manganese compounds and ammonium sulfate are detruded without any treatment or recovery. The compositions of the main elements in electrolytic manganese residue were analyzed comprehensively based on the extensive research data. According to the new development of electrolytic manganese residue comprehensively used in recent years,a water washing residue-twice precipitation process was also proposed. The experimental results indicate that manganese dioxide silicon dioxide and calcium sulfate are presented as amorphous state in the manganese residues. The recovery rates of manganese and nitrogen reach up to 99.5% and 94.5 %,respectively. The recovery process can be easily implemented,environment-friendly and fitting for industrial production.

  1. Alkaline solid polymer electrolytes and their application to rechargeable batteries; Electrolytes solides polymeres alcalins application aux generateurs electrochimiques rechargeables

    Energy Technology Data Exchange (ETDEWEB)

    Guinot, S.

    1996-03-15

    A new family of solid polymer electrolytes (SPE) based on polyoxyethylene (POE), KOH and water is investigated in view of its use in rechargeable batteries. After a short review on rechargeable batteries, the preparation of various electrolyte compositions is described. Their characterization by differential scanning calorimetry (DSC), thermogravimetric analysis, X-ray diffraction and microscopy confirm a multi-phasic structure. Conductivity measurements give values up to 10 sup -3 S cm sup -1 at room temperature. Their use in cells with nickel as negative electrode and cadmium or zinc as positive electrode has been tested; cycling possibility has been shown to be satisfactory. (C.B.) 113 refs.

  2. Anion exchange polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung; Kim, Dae Sik; Lee, Kwan-Soo

    2013-07-23

    Solid anion exchange polymer electrolytes and compositions comprising chemical compounds comprising a polymeric core, a spacer A, and a guanidine base, wherein said chemical compound is uniformly dispersed in a suitable solvent and has the structure: ##STR00001## wherein: i) A is a spacer having the structure O, S, SO.sub.2, --NH--, --N(CH.sub.2).sub.n, wherein n=1-10, --(CH.sub.2).sub.n--CH.sub.3--, wherein n=1-10, SO.sub.2-Ph, CO-Ph, ##STR00002## wherein R.sub.5, R.sub.6, R.sub.7 and R.sub.8 each are independently --H, --NH.sub.2, F, Cl, Br, CN, or a C.sub.1-C.sub.6 alkyl group, or any combination of thereof; ii) R.sub.9, R.sub.10, R.sub.11, R.sub.12, or R.sub.13 each independently are --H, --CH.sub.3, --NH.sub.2, --NO, --CH.sub.nCH.sub.3 where n=1-6, HC.dbd.O--, NH.sub.2C.dbd.O--, --CH.sub.nCOOH where n=1-6, --(CH.sub.2).sub.n--C(NH.sub.2)--COOH where n=1-6, --CH--(COOH)--CH.sub.2--COOH, --CH.sub.2--CH(O--CH.sub.2CH.sub.3).sub.2, --(C.dbd.S)--NH.sub.2, --(C.dbd.NH)--N--(CH.sub.2).sub.nCH.sub.3, where n=0-6, --NH--(C.dbd.S)--SH, --CH.sub.2--(C.dbd.O)--O--C(CH.sub.3).sub.3, --O--(CH.sub.2).sub.n--CH--(NH.sub.2)--COOH, where n=1-6, --(CH.sub.2).sub.n--CH.dbd.CH wherein n=1-6, --(CH.sub.2).sub.n--CH--CN wherein n=1-6, an aromatic group such as a phenyl, benzyl, phenoxy, methylbenzyl, nitrogen-substituted benzyl or phenyl groups, a halide, or halide-substituted methyl groups; and iii) wherein the composition is suitable for use in a membrane electrode assembly.

  3. Vitamin B12 deficiency.

    Science.gov (United States)

    Oh, Robert; Brown, David L

    2003-03-01

    Vitamin B12 (cobalamin) deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of neuropsychiatric disorders. The role of B12 deficiency in hyperhomocysteinemia and the promotion of atherosclerosis is only now being explored. Diagnosis of vitamin B12 deficiency is typically based on measurement of serum vitamin B12 levels; however, about 50 percent of patients with subclinical disease have normal B12 levels. A more sensitive method of screening for vitamin B12 deficiency is measurement of serum methylmalonic acid and homocysteine levels, which are increased early in vitamin B12 deficiency. Use of the Schilling test for detection of pernicious anemia has been supplanted for the most part by serologic testing for parietal cell and intrinsic factor antibodies. Contrary to prevailing medical practice, studies show that supplementation with oral vitamin B12 is a safe and effective treatment for the B12 deficiency state. Even when intrinsic factor is not present to aid in the absorption of vitamin B12 (pernicious anemia) or in other diseases that affect the usual absorption sites in the terminal ileum, oral therapy remains effective.

  4. Vitamin D – The Vitamin Hormone

    African Journals Online (AJOL)

    vitamin D are rickets in children and osteomalacia in adults. These are far from the ... been gained over the past 15 years, and with the growing issue ... epidemiologic studies have observed relationships between low ... Open Access article distributed under the terms of the ... 65 year olds and over. ... mentioned in Table 1.7.

  5. Electrolytes,water,acid-base imbalance

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    2010296 Utility of clinical exercise test in diagnosis of hypokalaemic periodic paralysis. LIU Mingsheng(刘明生),et al. Dept Neurol,PUMC & CAMS,Beijing l00730. Chin J Neurol 2010;43(5):328-330. Objective To assess the utility of changes of muscle strength and compound muscle action potential (CMAP) of abductor digiti minimi (ADM) muscle after the exercise test

  6. Vitamins C and E interact in juvenile Atlantic salmon (Salmo salar, L.).

    Science.gov (United States)

    Hamre, K; Waagbø, R; Berge, R K; Lie, O

    1997-01-01

    A two way regression study was performed to investigate the interactions between vitamins C and E, and the influence of dietary vitamin C on the development of vitamin E deficiency in first feeding Atlantic salmon. The fish were fed three levels of all-rac-alpha-tocopheryl acetate (0, 150, and 300 mg/kg), each with six levels of ascorbate monophosphate (0, 7.5, 15, 30, 45, and 60 mg/kg ascorbic acid equivalents). Vitamin C protected the fish against vitamin E deficiency in a dose dependent manner, as seen from the data on growth, mortality, hematology, and lipid oxidation in the liver, indicated by the concentration of malondialdehyde. Vitamin C did not influence the tissue levels of vitamin E, except in vitamin C deficiency, which induced a large drop in liver vitamin E concentration. The liver level of vitamin C increased in response to supplementation of both vitamins. The results indicate two different interaction mechanisms: a synergistic effect of simultaneous protection of the water and lipid phases against oxidation, and regeneration of vitamin E from the vitamin E radical by ascorbic acid.

  7. Semiconductor electrolyte photovoltaic energy converter

    Science.gov (United States)

    Anderson, W. W.; Anderson, L. B.

    1975-01-01

    Feasibility and practicality of a solar cell consisting of a semiconductor surface in contact with an electrolyte are evaluated. Basic components and processes are detailed for photovoltaic energy conversion at the surface of an n-type semiconductor in contact with an electrolyte which is oxidizing to conduction band electrons. Characteristics of single crystal CdS, GaAs, CdSe, CdTe and thin film CdS in contact with aqueous and methanol based electrolytes are studied and open circuit voltages are measured from Mott-Schottky plots and open circuit photo voltages. Quantum efficiencies for short circuit photo currents of a CdS crystal and a 20 micrometer film are shown together with electrical and photovoltaic properties. Highest photon irradiances are observed with the GaAs cell.

  8. Diabetes mellitus and electrolyte disorders

    Science.gov (United States)

    Liamis, George; Liberopoulos, Evangelos; Barkas, Fotios; Elisaf, Moses

    2014-01-01

    Diabetic patients frequently develop a constellation of electrolyte disorders. These disturbances are particularly common in decompensated diabetics, especially in the context of diabetic ketoacidosis or nonketotic hyperglycemic hyperosmolar syndrome. These patients are markedly potassium-, magnesium- and phosphate-depleted. Diabetes mellitus (DM) is linked to both hypo- and hyper-natremia reflecting the coexistence of hyperglycemia-related mechanisms, which tend to change serum sodium to opposite directions. The most important causal factor of chronic hyperkalemia in diabetic individuals is the syndrome of hyporeninemic hypoaldosteronism. Impaired renal function, potassium-sparing drugs, hypertonicity and insulin deficiency are also involved in the development of hyperkalemia. This article provides an overview of the electrolyte disturbances occurring in DM and describes the underlying mechanisms. This insight should pave the way for pathophysiology-directed therapy, thus contributing to the avoidance of the several deleterious effects associated with electrolyte disorders and their treatment. PMID:25325058

  9. Vitamin D and psoriasis.

    Science.gov (United States)

    Lowe, K E; Norman, A W

    1992-05-01

    Skin can serve as the source of vitamin D when exposed to sunlight so that cutaneous 7-dehydrocholesterol can be converted to the vitamin. Skin is also a target organ for the hormone form of vitamin D: 1,25-(OH)2D3. Both skin keratinocytes grown in tissue culture and samples of human skin have the nuclear receptor for 1,25(OH)2D3. New results suggest that this hormone or its analogs may be effective in treating some forms of psoriasis.

  10. Determination of Water-soluble Vitamins in Health Foods by UPLC%超高效液相色谱法测定保健食品中的多种水溶性维生素

    Institute of Scientific and Technical Information of China (English)

    蒲明清; 戴舒春; 张连龙; 周华生; 成恒嵩

    2012-01-01

    本文应用超高效液相色谱法,Acquity UPLC HSS T3 (2.1× 100 mm× 1.8 μm)柱,0.1%三氟乙酸-乙腈流动相,梯度洗脱,紫外和荧光串联检测器,可同时测定保健食品中6种水溶性维生素,其中包括Vc、B3、B1、B6、B11、B2等,该法线性范围宽,呈直线回归、相关性好、检测限低、分析速度快,其测定结果与国标法相吻合.%Water-soluble vitamins were determiend by Ultra-performance liquid chromatography (UPLC) equipping ultraviolet detector and fluorescence detector in series. Samples were separated by a Acquity UPLC HSS T3 (2.1×100 mm×1.8 urn) column using 0.1% tnfluoroacetic acid-acelonitnle as mobile phase in gradient elution mode. Six water-soluble vitamin components in health foods were simultaneously determined, including ascorbic acid (Vc), nicotinamide (B3), thiamine (B1), pyridoxine (B6), folic acid (B11), riboflavin (B2), etc. This method was enabled to achieve wide linear range, well correlation, low detection limit and fast analysis. The results were in accordance with those with GB methods.

  11. High temperature polymer electrolyte membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    K.Scott; M. Mamlouk

    2006-01-01

    One of the major issues limiting the introduction of polymer electrolyte membrane fuel cells (PEMFCs) is the low temperature of operation which makes platinum-based anode catalysts susceptible to poisoning by the trace amount of CO, inevitably present in reformed fuel. In order to alleviate the problem of CO poisoning and improve the power density of the cell, operating at temperature above 100 ℃ is preferred. Nafion(R) -type perfluorosulfonated polymers have been typically used for PEMFC. However, the conductivity of Nafion(R) -type polymers is not high enough to be used for fuel cell operations at higher temperature ( > 90 ℃) and atmospheric pressure because they dehydrate under these condition.An additional problem which faces the introduction of PEMFC technology is that of supplying or storing hydrogen for cell operation,especially for vehicular applications. Consequently the use of alternative fuels such as methanol and ethanol is of interest, especially if this can be used directly in the fuel cell, without reformation to hydrogen. A limitation of the direct use of alcohol is the lower activity of oxidation in comparison to hydrogen, which means that power densities are considerably lower. Hence to improve activity and power output higher temperatures of operation are preferable. To achieve this goal, requires a new polymer electrolyte membrane which exhibits stability and high conductivity in the absence of liquid water.Experimental data on a polybenzimidazole based PEMFC were presented. A simple steady-state isothermal model of the fuel cell is also used to aid in fuel cell performance optimisation. The governing equations involve the coupling of kinetic, ohmic and mass transport. This paper also considers the advances made in the performance of direct methanol and solid polymer electrolyte fuel cells and considers their limitations in relation to the source and type of fuels to be used.

  12. Thermoelectricity in confined liquid electrolytes

    CERN Document Server

    Dietzel, Mathias

    2015-01-01

    The electric field in an extended phase of a liquid electrolyte exposed to a temperature gradient is attributed to different thermophoretic mobilities of the ion species. As shown herein, such Soret-type ion thermodiffusion is not required to induce thermoelectricity even in the simplest electrolyte if it is confined between charged walls. The space charge of the electric double layer leads to selective ion diffusion driven by a temperature-dependent electrophoretic ion mobility, which -for narrow channels- may cause thermo-voltages larger in magnitude than for the classical Soret equilibrium.

  13. Evaluation of electrolyte imbalance among tuberculosis patients ...

    African Journals Online (AJOL)

    Adebimpe Wasiu Olalekan

    2015-02-24

    Feb 24, 2015 ... electrolyte and acid-base derangements frequently encountered in AIDS and TB, have ..... tuberculosis. Electrolyte and acid-base balance monitoring in ... National Agency for the Control of HIV/AIDS NACA. Preva- lence of ...

  14. Calcium and Vitamin D

    Science.gov (United States)

    ... Pizza, cheese, frozen 1 serving 115 mg Pudding, chocolate, prepared with 2% milk 4 oz 160 mg ... Treatment Medication and Treatment Adherence Calcium/Vitamin D Nutrition Overall Health Fractures/Fall Prevention Exercise/Safe Movement ...

  15. Pyridoxine (Vitamin B6)

    Science.gov (United States)

    ... product (NicAzel, Elorac Inc., Vernon Hills, IL), containing nicotinamide, azelaic acid, zinc, vitamin B6, copper, and folic ... children with asthma is unclear. Itchy and inflamed skin (atopic dermatitis (eczema)). Early research suggests that taking ...

  16. Vitamin B12

    Science.gov (United States)

    ... fortified. You can get the recommended amounts of vitamin B12 by eating a variety of the foods including: Organ meats (beef liver) Shellfish (clams) Meat, poultry, eggs, milk and other dairy foods Some breakfast cereals and ...

  17. Vitamin food fortification today

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Samaniego-Vaesken

    2012-04-01

    Full Text Available Historically, food fortification has served as a tool to address population-wide nutrient deficiencies such as rickets by vitamin D fortified milk. This article discusses the different policy strategies to be used today. Mandatory or voluntary fortification and fortified foods, which the consumer needs, also have to comply with nutritional, regulatory, food safety and technical issues. The ‘worldwide map of vitamin fortification’ is analysed, including differences between develop and developing countries. The vitamins, folate and vitamin D, are taken as practical examples in the review of the beneficial effect of different strategies on public health. The importance of the risk–benefit aspect, as well as how to identify the risk groups, and the food vehicles for fortification is discussed.

  18. B Vitamins Test

    Science.gov (United States)

    ... or thiamin Also known as: Vitamin F, Aneurin, Thiamine diphosphate (TDP) – physiologically active form Role: B1 is a ... Wernicke-Korsakoff syndrome – mental changes Test name: Thiamine (Thiamine diphosphate) in blood Other ways to measure: Transketolase (functional ...

  19. Vitamin A benefit (image)

    Science.gov (United States)

    ... the retina, which allows vision in dim light. Beta carotene, the precursor to vitamin A found in vegetables, has antioxidant properties, which means it protects cells from the daily toxic damage of oxidation.

  20. Vitamins and Minerals

    Science.gov (United States)

    ... minerals your body needs. But if you're skipping meals, dieting, or if you're concerned that ... Kids For Parents MORE ON THIS TOPIC Healthy Breakfast Planner Nutrition & Fitness Center Vitamin D Figuring Out ...

  1. 以明胶为壁材制备水溶性复合维生素微胶囊工艺%Preparation of Water-Soluble Vitamin B Complex Microcapsules Using Gelatin as Wall Material

    Institute of Scientific and Technical Information of China (English)

    井乐刚; 赵新淮

    2012-01-01

    以明胶为壁材,以盐酸硫胺素(VB1)、核黄素(VB2)、盐酸吡哆醇(VB6)、叶酸、烟酰胺的混合物为芯材,采用喷雾干燥工艺,制备水溶性复合维生素微胶囊。通过正交试验,考察壁材芯材比、进风温度、进料流量等工艺参数对微胶囊包埋率及产品得率的影响。结果表明:壁材芯材比对包埋率的影响最显著,进风温度对产品得率的影响比较大;较为适宜的喷雾干燥工艺条件为壁材芯材比10:1、进风温度170℃、进料流量3mL/min。在此条件下制备的水溶性复合维生素微胶囊,少数为球形,大多数表面有凹陷,平均粒径为8.93μm。%Water-soluble vitamin B complex microcapsules were prepared by spray-drying technique using gelatin as wall material and a mixture of thiamine hydrochloride(vitamin B1),riboflavin(vitamin B2),pyridoxine hydrochloride(vitamin B6),folic acid and nicotinamide as core material.The effects of technological parameters including wall material/core material mass ratio,inlet temperature,and feeding rate on microencapsulation efficiency and microcapsule yield were investigated using an orthogonal array design.The microencapsulation efficiency was determined by fluorospectrophotometry.Characteristics microcapsule shape and granule size distribution) of microencapsulated vitamins B were evaluated by scanning electron microscopy(SEM) and laser particle size analyzer.The results showed that the most significant factor affecting microencapsulation efficiency was wall material/core material mass ratio,followed by inlet temperature and feeding rate.Microcapsule yield was significantly by inlet temperature and little affected by feeding rate and wall material/core material mass ratio.The optimal microencapsulation conditions were obtained as follows: wall material/core material mass ratio 10:1,inlet temperature 170 ℃,and feeding rate 3 mL/ min.SEM observations showed that few microcapsules were

  2. Vitamin D supplementation guidelines.

    Science.gov (United States)

    Pludowski, Pawel; Holick, Michael F; Grant, William B; Konstantynowicz, Jerzy; Mascarenhas, Mario R; Haq, Afrozul; Povoroznyuk, Vladyslav; Balatska, Nataliya; Barbosa, Ana Paula; Karonova, Tatiana; Rudenka, Ema; Misiorowski, Waldemar; Zakharova, Irina; Rudenka, Alena; Łukaszkiewicz, Jacek; Marcinowska-Suchowierska, Ewa; Łaszcz, Natalia; Abramowicz, Pawel; Bhattoa, Harjit P; Wimalawansa, Sunil J

    2017-02-12

    Research carried out during the past two-decades extended the understanding of actions of vitamin D, from regulating calcium and phosphate absorption and bone metabolism to many pleiotropic actions in organs and tissues in the body. Most observational and ecological studies report association of higher serum 25-hydroxyvitamin D [25(OH)D] concentrations with improved outcomes for several chronic, communicable and non-communicable diseases. Consequently, numerous agencies and scientific organizations have developed recommendations for vitamin D supplementation and guidance on optimal serum 25(OH)D concentrations. The bone-centric guidelines recommend a target 25(OH)D concentration of 20ng/mL (50nmol/L), and age-dependent daily vitamin D doses of 400-800IU. The guidelines focused on pleiotropic effects of vitamin D recommend a target 25(OH)D concentration of 30ng/mL (75nmol/L), and age-, body weight-, disease-status, and ethnicity dependent vitamin D doses ranging between 400 and 2000IU/day. The wise and balanced choice of the recommendations to follow depends on one's individual health outcome concerns, age, body weight, latitude of residence, dietary and cultural habits, making the regional or nationwide guidelines more applicable in clinical practice. While natural sources of vitamin D can raise 25(OH)D concentrations, relative to dietary preferences and latitude of residence, in the context of general population, these sources are regarded ineffective to maintain the year-round 25(OH)D concentrations in the range of 30-50ng/mL (75-125nmol/L). Vitamin D self-administration related adverse effects, such as hypercalcemia and hypercalciuria are rare, and usually result from taking extremely high doses of vitamin D for a prolonged time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Polymer Electrolytes for Lithium/Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    The Nam Long Doan

    2012-08-01

    Full Text Available This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes.

  4. VITAMIN D IMMUNOMODULATORY EFFECT

    Directory of Open Access Journals (Sweden)

    Jelena Radović

    2012-01-01

    Full Text Available In addition to the classical role in the homeostasis of calcium and phosphorus, vitamin D shows a regulatory effect on a number of different cells, especially its antiproliferative and pro-differential biological function. Through its own receptor in the immune cells, vitamin D increases the phagocytic activity of macrophages and NK cells. Also, by binding to the regulatory sequences of antimicrobial peptides genes, vitamin D increases the microbicidal activity of phagocytes. Inhibition of differentiation and maturation of antigen-presenting dendritic cells, as well as direct influence on their contact with T lymphocytes, it significantlly influences the type of immune response. Dendritic cells under the influence of vitamin D induce a suppressor T cells, which can inhibit Th1 cell response and are critical in the regulation of immune tolerance. Vitamin D inhibits proliferation of Th1 and Th17 cells, as well their cytokine production, and suppresses the differentiation and maturation of B lymphocytes. Due to all these functions, vitamin D has shown beneficial effects in the prevention and modification of a number of autoimmune diseases. On the other hand, immunity disorders with predominant Th2 response (asthma, allergies did not show such good results after the use of hypocalcemic VDR agonists.

  5. Optimization of non-aqueous electrolytes for Primary lithium/air batteries operated in Ambient Enviroment

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wu; Xiao, Jie; Zhang, Jian; Wang, Deyu; Zhang, Jiguang

    2009-07-07

    The selection and optimization of non-aqueous electrolytes for ambient operations of lithium/air batteries has been studied. Organic solvents with low volatility and low moisture absorption are necessary to minimize the change of electrolyte compositions and the reaction between lithium anode and water during discharge process. It is critical to make the electrolytes with high polarity so that it can reduce wetting and flooding of carbon based air electrode and lead to improved battery performance. For ambient operations, the viscosity, ionic conductivity, and oxygen solubility of the electrolyte are less important than the polarity of organic solvents once the electrolyte has reasonable viscosity, conductivity, and oxygen solubility. It has been found that PC/EC mixture is the best solvent system and LiTFSI is the most feasible salt for ambient operations of Li/air batteries. Battery performance is not very sensitive to PC/EC ratio or salt concentration.

  6. Mathematical modeling of polymer electrolyte fuel cells

    Science.gov (United States)

    Sousa, Ruy; Gonzalez, Ernesto R.

    Fuel cells with a polymer electrolyte membrane have been receiving more and more attention. Modeling plays an important role in the development of fuel cells. In this paper, the state-of-the-art regarding modeling of fuel cells with a polymer electrolyte membrane is reviewed. Modeling has allowed detailed studies concerning the development of these cells, e.g. in discussing the electrocatalysis of the reactions and the design of water-management schemes to cope with membrane dehydration. Two-dimensional models have been used to represent reality, but three-dimensional models can cope with some important additional aspects. Consideration of two-phase transport in the air cathode of a proton exchange membrane fuel cell seems to be very appropriate. Most fuel cells use hydrogen as a fuel. Besides safety concerns, there are problems associated with production, storage and distribution of this fuel. Methanol, as a liquid fuel, can be the solution to these problems and direct methanol fuel cells (DMFCs) are attractive for several applications. Mass transport is a factor that may limit the performance of the cell. Adsorption steps may be coupled to Tafel kinetics to describe methanol oxidation and methanol crossover must also be taken into account. Extending the two-phase approach to the DMFC modeling is a recent, important point.

  7. Optimizing end-group cross-linking polymer electrolytes for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung [Los Alamos National Laboratory; Lee, Kwan Soo [Los Alamos National Laboratory; Jeong, Myung - Hwan [GIST, KOREA; Lee, Jae - Suk [GIST, KOREA

    2009-01-01

    This paper demonstrates the optimization of proton conductivity and water uptake for cross-linkable polymer electrolytes through synthesis and characterization of end-group cross-linkable sulfonated poly(arylene ether) copolymers (ESF-BPs). The extent of reaction of cross-linking was controlled by reaction time resulting in a series of polymers with two, independent tunable parameters, degree of sulfonation (DS) and degree of cross-linking (DC). For the polymers presented, cross-linking improved proton conductivity while reducing water uptake, an uncommon trend in polymer electrolytes where water is critical for proton conduction. Other trends relating to changes are reported and the results yield insight into the role of DS and DC and how to optimize electrochemical properties and performance of polymer electrolytes through these tunable parameters. Select polymer electrolytes were tested in fuel cells where performance and durability with accelerated relative humidity cycling were compared with Nafion{reg_sign}.

  8. Electrolytes for magnesium electrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Burrell, Anthony K.; Sa, Niya; Proffit, Danielle Lee; Lipson, Albert; Liao, Chen; Vaughey, John T.; Ingram, Brian J.

    2017-07-04

    An electrochemical cell includes a high voltage cathode configured to operate at 1.5 volts or greater; an anode including Mg.sup.0; and an electrolyte including an ether solvent and a magnesium salt; wherein: a concentration of the magnesium salt in the ether is 1 M or greater.

  9. Vitamin composition of ethnic foods commonly consumed in Europe

    Directory of Open Access Journals (Sweden)

    Jane Ireland

    2012-04-01

    Full Text Available Background: Vitamin analyses are particularly important for estimating dietary intakes, determining nutritional status and regulating food labelling. Due to the increased popularity of ethnic foods, the vitamin composition of these foods is required to ensure that national food databases are up-to-date.Objectives: The key objective of this study was to generate new and reliable data on the contents of fat-soluble vitamins, including vitamins A (all trans-retinol, D3 & E (α-tocopherol and those that are water-soluble (vitamins B6, B12, C, biotin, folate, niacin, pantothenic acid, riboflavin, and thiamin in ethnic foods commonly consumed in Europe.Design: Thirty commonly-consumed ethnic foods in Europe (from Belgium, France, Israel, Italy, The Netherlands, and the UK were analysed using harmonised methodologies for identification of representative foods, sampling, data scrutiny and documentation to generate reliable data. Analyses were carried out using International standard methods. Results: Certain vitamins were present in appreciable amounts: β-carotene in tayer leaves (7919µg/100g, thiamin in frik dry (0.24mg/100g, riboflavin in mbinzo worms (0.79mg/100g, and niacin in commercial soy patty (17.5mg/100g. However, retinol, pantothenic acid, vitamins D and B12 were below detectable levels in the majority of the foods analysed.Conclusions: The majority of the foods contained most of the water-soluble vitamins but lacked fat-soluble vitamins. However, these preliminary data represent only a small number of foods per country and so no conclusions about vitamin imbalances can be drawn. Additional data are required on a much wider range of commonly-consumed ethnic foods to make firm conclusions about adequacy of diets.

  10. Identification of differentially expressed proteins in vitamin B 12

    Directory of Open Access Journals (Sweden)

    Swati Varshney

    2015-01-01

    Full Text Available Background: Vitamin B 12 (cobalamin is a water-soluble vitamin generally synthesized by microorganisms. Mammals cannot synthesize this vitamin but have evolved processes for absorption, transport and cellular uptake of this vitamin. Only about 30% of vitamin B 12 , which is bound to the protein transcobalamin (TC (Holo-TC [HoloTC] enters into the cell and hence is referred to as the biologically active form of vitamin B 12 . Vitamin B 12 deficiency leads to several complex disorders, including neurological disorders and anemia. We had earlier shown that vitamin B 12 deficiency is associated with coronary artery disease (CAD in Indian population. In the current study, using a proteomics approach we identified proteins that are differentially expressed in the plasma of individuals with low HoloTC levels. Materials and Methods: We used isobaric-tagging method of relative and absolute quantitation to identify proteins that are differently expressed in individuals with low HoloTC levels when compared to those with normal HoloTC level. Results: In two replicate isobaric tags for relative and absolute quantitation experiments several proteins involved in lipid metabolism, blood coagulation, cholesterol metabolic process, and lipoprotein metabolic process were found to be altered in individuals having low HoloTC levels. Conclusions: Our study indicates that low HoloTc levels could be a risk factor in the development of CAD.

  11. Detection of water-solution vitamins in embroynated eggs and its changes during incubate%鸡胚蛋中水溶性维生素的测定及其孵化期间的变化

    Institute of Scientific and Technical Information of China (English)

    范亮; 张彧; 陈历俊; 姜铁民

    2012-01-01

    The assessment and validation of reliable and analytical method for the derermination of warer-solution vitamins,The recov-ery of the five kinds of vitamins are more than 90% and it appearsavery good linearny during 0.1~50μg/mL.ARP-HPLC method was put to use to detect five water-soluble vitamins(riboflavin,niacin.niacinamide.pyridoxin folic acid)in different incubate period(the0th,2th,4th,6th,8th,10th,12th,14th,16th and 18th day after incubate)embroynated eggs and made a comparison with the fresh egg,the results indicated that as the incubate gose on,the content of riboflavin,niacin and folic aeid had made a increase at different level,the content of niacin inthe 18th day of embroynated eggs is 3.2 times thanfresh eggs,as to riboflavin,this amount is 31%,the biggest content of folic acid appears the 12th day,it is the twice amount of the limit of detection.%对鸡胚蛋中水溶性维生素的色谱测定方法进行优化和验证,5种维生素的加标回收率均在90%以上,且在0.1~50 μg/mL具有良好的线性相关性;采用RP- HPLC对不同胚龄(即入孵的第0、2、4、6、8、10、12、14、16和18天)肉鸡胚胎发育过程中的5种水溶性维生素(核黄素、烟酸、烟酰胺、吡哆醇和叶酸)进行测定与分析,并与鲜蛋进行对比.结果表明,随着孵化时间的延长,维生素B2、烟酸和叶酸3种维生素均有不同程度的增加,其中烟酸增加3.2倍,维生素B2增加31%;叶酸在12d达到最高,比鲜蛋约增加1倍;未能检测出维生素B6和烟酰胺.

  12. Vitamin D, Calcium, and Bone Health

    Science.gov (United States)

    ... in Balance › Vitamin D, Calcium, and Bone Health Vitamin D, Calcium, and Bone Health March 2012 Download ... also helps keep your bones strong. Why are vitamin D and calcium important to bone health? Vitamin ...

  13. Single-laboratory validation of a high-performance liquid chromatographic-diode array detector-fluorescence detector/mass spectrometric method for simultaneous determination of water-soluble vitamins in multivitamin dietary tablets.

    Science.gov (United States)

    Chen, Pei; Atkinson, Renata; Wolf, Wayne R

    2009-01-01

    The purpose of this study was to develop a single-laboratory validated (SLV) method using high-performance liquid chromatography with different detectors [diode array detector (DAD); fluorescence detector (FLD); and mass spectrometry (MS)] for determination of 7 B-complex vitamins (B1-thiamin, B2-riboflavin, B3-nicotinamide, B6-pyridoxine, B9-folic acid, pantothenic acid, and biotin) and vitamin C in multivitamin/multimineral dietary supplements. The method involves the use of a reversed-phase octadecylsilyl column (4 microm, 250 x 2.0 mm id) and a gradient mobile phase profile. Gradient elution was performed at a flow rate of 0.25 mL/min. After a 5 min isocratic elution at 100% A (0.1% formic acid in water), a linear gradient to 50% A and 50% B (0.1% formic acid in acetonitrile) at 15 min was employed. Detection was performed with a DAD as well as either an FLD or a triple-quadrupole MS detector in the multiple reaction monitoring mode. SLV was performed using Standard Reference Material (SRM) 3280 Multivitamin/Multimineral Tablets, being developed by the National Institute of Standards and Technology, with support by the Office of Dietary Supplements of the National Institutes of Health. Phosphate buffer (10 mM, pH 2.0) extracts of the NIST SRM 3280 were analyzed by the liquid chromatographic (LC)-DAD-FLDIMS method. Following extraction, the method does not require any sample cleanup/preconcentration steps except centrifugation and filtration.

  14. Vitamin D and female fertility.

    Science.gov (United States)

    Lerchbaum, Elisabeth; Rabe, Thomas

    2014-06-01

    Apart from the well known effects of vitamin D on maintaining calcium homeostasis and promoting bone mineralization, there is some evidence suggesting that vitamin D also modulates human reproductive processes. We will review the most interesting and relevant studies on vitamin D and female fertility published over the past year. In the past year, several observational studies reported a better in-vitro fertilization outcome in women with sufficient vitamin D levels (≥30 ng/ml), which was mainly attributed to vitamin D effects on the endometrium. One randomized controlled trial found an increased endometrial thickness in women with polycystic ovary syndrome (PCOS) receiving vitamin D during intrauterine insemination cycles. Further, vitamin D supplementation had a beneficial effect on serum lipids in PCOS women. Vitamin D treatment improved endometriosis in a rat model and increased vitamin D intake was related to a decreased risk of incident endometriosis. Vitamin D was also favorably associated with primary dysmenorrhea, uterine leiomyoma, and ovarian reserve in late reproductive aged women. In women undergoing in-vitro fertilization, a sufficient vitamin D level (≥30 ng/ml) should be obtained. Vitamin D supplementation might improve metabolic parameters in women with PCOS. A high vitamin D intake might be protective against endometriosis.

  15. Vitamin D: the role of the sunshine vitamin

    OpenAIRE

    Mutsatsa, S.; Mushore, M.; Ncube, K.; Currid, T. J.

    2013-01-01

    The importance of vitamin D in physical disorders has been well documented. Deficiency in this vitamin is associated with a wide range of physical and mental disorders that include, heart problems, hypertension, stroke, diabetes, various cancers, and asthma. In mental health vitamin D deficiency is associated with schizophrenia, depression, anxiety, Alzheimer’s disease among others. Risk factors for vitamin D deficiency include darker skin, lack of adequate sun exposure, autoimmune diseases, ...

  16. Efficient Electrolytes for Lithium-Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Natarajan eAngulakshmi

    2015-05-01

    Full Text Available This review article mainly encompasses on the state-of-the-art electrolytes for lithium–sulfur batteries. Different strategies have been employed to address the issues of lithium-sulfur batteries across the world. One among them is identification of electrolytes and optimization of their properties for the applications in lithium-sulfur batteries. The electrolytes for lithium-sulfur batteries are broadly classified as (i non-aqueous liquid electrolytes, (ii ionic liquids, (iii solid polymer and (iv glass-ceramic electrolytes. This article presents the properties, advantages and limitations of each type of electrolytes. Also the importance of electrolyte additives on the electrochemical performance of Li-S cells is discussed.

  17. Theory of electrolyte crystallization in magnetic field

    DEFF Research Database (Denmark)

    Madsen, Hans Erik Lundager

    2007-01-01

    Crystallization from aqueous solution of a sparingly soluble electrolyte is accelerated by magnetic field if the crystalizing phase is a diamagnetic salt of a weak acid, and crystallization is from neutral or acid solution in ordinary (not heavy) water. Since the effect of Lorentz force...... is negligible, if not absent, the key property is likely to be the spin of protons which, by virtue of their half-integral spin, are fermions. An effect on crystal growth kinetics has been demonstrated, and the apparent effect on nucleation concerns the growth rate of nuclei. We are thus dealing with surface...... phenomena. The basis of the theory is a crystal model of a sparingly soluble salt with NaCl structure, where the ions are divalent, and the anion is a base. It is assumed that almost all the anions in the surface layer are protonized, and that an approaching metal ion pushes the proton away...

  18. Advanced composite polymer electrolyte fuel cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.S.; Zawodzinski, T.A.; Gottesfeld, S.; Kolde, J.A.; Bahar, B.

    1995-09-01

    A new type of reinforced composite perfluorinated polymer electrolyte membrane, GORE-SELECT{trademark} (W.L. Gore & Assoc.), is characterized and tested for fuel cell applications. Very thin membranes (5-20 {mu}m thick) are available. The combination of reinforcement and thinness provides high membrane, conductances (80 S/cm{sup 2} for a 12 {mu}m thick membrane at 25{degrees}C) and improved water distribution in the operating fuel cell without sacrificing longevity or durability. In contrast to nonreinforced perfluorinated membranes, the x-y dimensions of the GORE-SELECT membranes are relatively unaffected by the hydration state. This feature may be important from the viewpoints of membrane/electrode interface stability and fuel cell manufacturability.

  19. Electrolytic production of hydrogen utilizing photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, M.A.

    1996-10-01

    Hydrogen has the potential to serve as both an energy storage means and an energy carrier in renewable energy systems. When renewable energy sources such as solar or wind power are used to produce electrical power, the output can vary depending on weather conditions. By using renewable sources to produce hydrogen, a fuel which can be stored and transported, a reliable and continuously available energy supply with a predictable long-term average output is created. Electrolysis is one method of converting renewable energy into hydrogen fuel. In this experiment we examine the use of an electrolyzer based on polymer-electrolyte membrane technology to separate water into hydrogen and oxygen. The oxygen is vented to the atmosphere and the hydrogen is stored in a small pressure vessel.

  20. Two-phase flow modeling for the cathode side of a Polymer electrolyte fuel cell

    NARCIS (Netherlands)

    Qin, C.; Rensink, D.; Fell, S.; Hassanizadeh, S.M.

    2012-01-01

    Liquid water flooding in micro gas channels is an important issue in the water management of polymer electrolyte fuel cells (PEFCs). However, in most previous numerical studies liquid water transport in the gas channels (GC) has been simplified by the mist flow assumption. In this work, we present a

  1. Vitamin D endocrinology

    Energy Technology Data Exchange (ETDEWEB)

    DeLuca, H.F.

    1976-09-01

    Current status of our understanding of the metabolism of vitamin D and its implications in metabolic bone disease is reviewed. The details of metabolism of vitamin D/sub 3/ to 25-hydroxyvitamin D/sub 3/ in the liver and its further conversion in the kidney to either 1,25-dihydroxyvitamin D/sub 3/ or 24,25-dihydroxyvitamin D/sub 3/ are presented. The latter conversions are regulated by the vitamin D status, serum calcium through the parathyroid gland system, and serum inorganic phosphorus concentration. The 1,25-dihydroxyvitamin D/sub 3/ can now be regarded as a calcium- and a phosphate-mobilizing hormone and must be considered as one of the most important serum calcium-regulating hormones. Disruption of the vitamin D metabolic sequence or the signal system for 1,25-dihydroxyvitamin D/sub 3/ results in several bone and calcium metabolism disorders such as renal osteodystrophy, hypoparathyroidism, pseudohypoparathyroidism, and vitamin D-dependency rickets. The use of the synthetic analogs of 1,25-dihydroxyvitamin D/sub 3/ as well as 1,25-dihydroxyvitamin D/sub 3/ itself in the management of these disease states is discussed.

  2. Vitamin D and Cancer*

    Directory of Open Access Journals (Sweden)

    Doré Jean-François

    2014-05-01

    Full Text Available Epidemiological studies, mostly ecological but also case-control and prospective studies show a negative association between residential sun exposure and incidence (or fatality of major cancers: colon, breast, and prostate cancer, and non-Hodgkin lymphoma. And it has been suggested that this reduction in risk could be influenced by vitamin D synthesized in the skin as a result of sun exposure. Low serum vitamin D levels are linked to an increase in risk of colon cancer, and to a lesser extent to risk of breast cancer, but not to risk of prostate cancer or non-Hodgkin lymphoma. Intervention trials consisting in daily supplementation in vitamin D for several years have all failed to demonstrate an effect on cancer incidence. Hence, it is not clear whether the reduction in cancer risk associated with sun exposure is mediated by vitamin D or by another factor influenced by sun exposure such as inflammation or immunosuppression, or whether a low vitamin D status is simply a consequence of ill health.

  3. A biodegradable gel electrolyte for use in high-performance flexible supercapacitors.

    Science.gov (United States)

    Moon, Won Gyun; Kim, Gil-Pyo; Lee, Minzae; Song, Hyeon Don; Yi, Jongheop

    2015-02-18

    Despite the significant advances in solid polymer electrolytes used for supercapacitors, intractable problems including poor ionic conductivity and low electrochemical performance limit the practical applications. Herein, we report a facile approach to synthesize a NaCl-agarose gel electrolyte for use in flexible supercapacitors. The as-prepared agarose hydrogel consists of a three-dimensional chemically interconnected agarose backbone and oriented interparticular submicropores filled with water. The interconnected agarose matrix acts as a framework that provides mechanical stability to the gel electrolyte and hierarchical porous networks for optimized ion transport. The developed pores with the water filler provide an efficient ionic pathway to the storage sites of electrode. With these properties, the gel electrolyte enables the supercapacitor to have a high specific capacitance of 286.9 F g(-1) and a high rate capability that is 80% of specific capacitance obtained in the case of a liquid electrolyte at 100 mV s(-1). In addition, attributed to the simple procedure and its components, the gel electrolyte is highly scalable, cost-effective, safe, and nontoxic. Thus, the developed gel electrolyte has the potential for use in various energy storage and delivery systems.

  4. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... consuming foods, with supplementation suggested for certain sensitive populations. These guidelines, published by the Department of Health ... acid, and vitamins E and D (for specific population groups). Regarding the use of vitamin supplements, the ...

  5. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... and vitamins E and D (for specific population groups). Regarding the use of vitamin supplements, the Dietary ... and beverages within and among the basic food groups. At the same time, choose foods that limit ...

  6. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... calcium, potassium, fiber, magnesium, and vitamin E (for children and adolescents) vitamin B-12, iron, folic acid, ... Older Adults More in Consumer Updates Animal & Veterinary Children's Health Cosmetics Dietary Supplements Drugs Food Medical Devices ...

  7. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... vitamins A (as carotenoids), C, and E (for adults) calcium, potassium, fiber, magnesium, and vitamin E (for ... a varied diet. If you are an older adult, have dark skin, or are exposed to insufficient ...

  8. Vitamin Fortification of Fluid Milk.

    Science.gov (United States)

    Yeh, Eileen B; Barbano, David M; Drake, MaryAnne

    2017-04-01

    Vitamin concentrates with vitamins A and D are used for fortification of fluid milk. Although many of the degradation components of vitamins A and D have an important role in flavor/fragrance applications, they may also be source(s) of off-flavor(s) in vitamin fortified milk due to their heat, oxygen, and the light sensitivity. It is very important for the dairy industry to understand how vitamin concentrates can impact flavor and flavor stability of fluid milk. Currently, little research on vitamin degradation products can be found with respect to flavor contributions. In this review, the history, regulations, processing, and storage stability of vitamins in fluid milk are addressed along with some hypotheses for the role of vitamin A and D fortification on flavor and stability of fluid milk.

  9. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... For Consumers Consumer Updates Fortify Your Knowledge About Vitamins Share Tweet Linkedin Pin it More sharing options ... their health regimen. back to top Why Buy Vitamins? There are many good reasons to consider taking ...

  10. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... For Consumers Consumer Updates Fortify Your Knowledge About Vitamins (video) Share Tweet Linkedin Pin it More sharing ... Consumer Update Although most people get all the vitamins they need from the foods they eat, millions ...

  11. Vitamin Supplements: Healthy or Hoax?

    Science.gov (United States)

    ... Recognition & Awards Healthy Workplace Food and Beverage Toolkit Vitamin Supplements: Healthy or Hoax? Updated:Jun 12,2015 Can vitamin and mineral supplements really make you healthier? Overwhelmed ...

  12. Fortify Your Knowledge about Vitamins

    Science.gov (United States)

    ... Consumers Home For Consumers Consumer Updates Fortify Your Knowledge About Vitamins (video) Share Tweet Linkedin Pin it ... doing so safely. For More Information Fortify Your Knowledge About Vitamins FoodSafety.gov: Your Gateway to Federal ...

  13. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... Consumers Home For Consumers Consumer Updates Fortify Your Knowledge About Vitamins (video) Share Tweet Linkedin Pin it ... doing so safely. For More Information Fortify Your Knowledge About Vitamins FoodSafety.gov: Your Gateway to Federal ...

  14. Calcium, vitamin D and bone

    OpenAIRE

    Borg, Andrew A.

    2012-01-01

    Calcium, protein and vitamin D are the main nutrients relevant to bone health. This short article discusses the importance of vitamin D and its relation to calcium homeostasis. The various causes, clinical manifestations and treatment are outlined.

  15. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... over-the-counter multivitamins. According to the American Academy of Family Physicians (AAFP), a doctor may recommend ... vitamins.” For some vitamins and minerals, the National Academy of Sciences has established upper limits of intake ( ...

  16. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... multivitamins. According to the American Academy of Family Physicians (AAFP), a doctor may recommend that you take them: for certain ... If you take blood thinners, talk to your doctor before taking vitamin E or vitamin K pills. ...

  17. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... that the body absolutely needs: vitamins A, C, D, E, K, and the B vitamins (thiamine, riboflavin, ... comes to purchasing dietary supplements, Vasilios Frankos, Ph.D., Director of FDA's Division of Dietary Supplement Programs, ...

  18. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... For Consumers Consumer Updates Fortify Your Knowledge About Vitamins Share Tweet Linkedin Pin it More sharing options ... their health regimen. back to top Why Buy Vitamins? There are many good reasons to consider taking ...

  19. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... For Consumers Consumer Updates Fortify Your Knowledge About Vitamins (video) Share Tweet Linkedin Pin it More sharing ... Consumer Update Although most people get all the vitamins they need from the foods they eat, millions ...

  20. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... Today's dietary supplements are not only vitamins and minerals. "They also include other less familiar substances such ... dietary ingredient" category are not only vitamins, but minerals, botanicals products, amino acids, and substances such as ...

  1. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... vitamins for a variety of biological processes, including growth, digestion, and nerve function. There are 13 vitamins ... product worth the money?'" Frankos advises. "Resist the pressure to buy a product or treatment on the ...

  2. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... vitamins A (as carotenoids), C, and E (for adults) calcium, potassium, fiber, magnesium, and vitamin E (for ... a varied diet. If you are an older adult, have dark skin, or are exposed to insufficient ...

  3. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... the FDA's YouTube Channel. Get Consumer Updates by E-mail Consumer Updates RSS Feed Download PDF (422 ... the body absolutely needs: vitamins A, C, D, E, K, and the B vitamins (thiamine, riboflavin, niacin, ...

  4. [The indices of water-salt metabolism and of the endocrine status in monkeys after flights on the Kosmos biological satellites].

    Science.gov (United States)

    Korol'kov, V I; Dotsenko, M A; Larina, I M; Shakhmatova, E I; Natochin, Iu V

    1996-01-01

    Findings of studying the indices of water-salt metabolism and endocrine status of monkeys after their exposure in the weightless environment onboard the biological satellites of Earth have revealed a change in the blood serum concentrations of electrolytes which is indicative of instability of the system responsible for maintenance of the fluid-mineral homeostasis during readaptation. Results of studying the endocrine status of monkeys infer alteration in calcium metabolism, i.e. decreased levels of parathyroid hormone, calcitonin and the transport form of vitamin D3.

  5. Experimental investigation into the transmembrane electrical potential of the forward osmosis membrane process in electrolyte solutions.

    Science.gov (United States)

    Bian, Lixia; Fang, Yanyan; Wang, Xiaolin

    2014-06-19

    The transmembrane electrical potential (TMEP) in a forward osmosis membrane process with a single electrolyte solution as the draw and feed solutions was investigated by experiments. The effects of membrane orientation, the electrolyte species (KCl, NaCl, MgCl2, and CaCl2), concentration and concentration ratio of solutions at both sides of membrane on water flux and TMEP were investigated. The results showed that the TMEPs at different membrane orientation cannot completely coincide, which confirmed the effect of membrane asymmetry. The ion diffusion coefficients significantly affected the TMEP across the membrane, with different patterns for different electrolytes and concentrations.

  6. Polymer electrolytes for rechargeable lithium batteries. Final report; Polymere Elektrolyte fuer wiederaufladbare Lithium-Batterien. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Sandner, B. [Halle-Wittenberg Univ., Merseburg (Germany). Inst. fuer Technische und Makromolekulare Chemie; Wegner, G.; Meyer, W. [Max-Planck-Institut fuer Polymerforschung, Mainz (Germany); Bronstert, B.; Moehwald, H.; Hennig, I. [BASF AG, Ludwigshafen am Rhein (Germany). Kunststofflaboratorium

    1999-07-01

    Rechargeable lithium batteries with water-free organic electrolytes have the highest energy density of all battery systems. Some of their weak points, e.g. concerning safety, cell production, cost etc. could be overcome by replacing the liquid low-molecular electrolytes with polymer electrolytes. The investigation focused on acrylically unsaturated oligomers/prepolymers. [German] Wiederaufladbare Lithiumbatterien mit wasserfreien organischen Elektrolyten sind die Akkumulatoren mit der hoechsten Energiedichte. Durch Ersatz der fluessigen niedermolekularen Elektrolyte durch Polymerfestelektrolyte koennen manche Schwachpunkte dieser Batterien, vor allem bezueglich Sicherheit, Zellfertigung, Kosten, etc., ausgeraeumt werden. Ausgangspunkt der Arbeiten waren acrylisch ungesaettigte Oligomere/Praepolymere. (orig.)

  7. Sol-Gel Electrolytes Incorporated by Lanthanide Luminescent Materials and Their Photophysical Properties

    Science.gov (United States)

    Yu, Chufang; Zhang, Zhengyang; Fu, Meizhen; Gao, Jinwei; Zheng, Yuhui

    2017-10-01

    A group of silica gel electrolytes with lanthanide luminescent hybrid materials were assembled and investigated. Photophysical studies showed that terbium and europium hybrids displayed characteristic green and red emissions within the electrolytes. The influence of different concentration of the lanthanide hybrids on the electrochemical behavior of a gelled electrolyte valve-regulated lead-acid battery were studied through cyclic voltammograms, electrochemical impedance spectroscopy, water holding experiments and mobility tests. The morphology and particle size were analyzed by scanning electron microscopy. The results proved that lanthanide (Tb3+/Eu3+) luminescent materials are effective additives which will significantly improve the electrochemical properties of lead-acid batteries.

  8. Experimental Investigation into the Transmembrane Electrical Potential of the Forward Osmosis Membrane Process in Electrolyte Solutions

    Directory of Open Access Journals (Sweden)

    Lixia Bian

    2014-06-01

    Full Text Available The transmembrane electrical potential (TMEP in a forward osmosis membrane process with a single electrolyte solution as the draw and feed solutions was investigated by experiments. The effects of membrane orientation, the electrolyte species (KCl, NaCl, MgCl2, and CaCl2, concentration and concentration ratio of solutions at both sides of membrane on water flux and TMEP were investigated. The results showed that the TMEPs at different membrane orientation cannot completely coincide, which confirmed the effect of membrane asymmetry. The ion diffusion coefficients significantly affected the TMEP across the membrane, with different patterns for different electrolytes and concentrations.

  9. Elevated Vitamin B12 Levels

    Directory of Open Access Journals (Sweden)

    Melike Sezgin Evim

    2014-12-01

    Full Text Available Vitamin B12 is essential to all cells in the body. Both high levels and low levels of vitamin B12 are significant. High serum cobalamin (vitamin B12 levels are found particularly in hematological disorders, solid tumors, autoimmune diseases, renal diseases and infectious diseases; and this elevation is associated with prognosis in some of these diseases. High levels of serum vitamin B12 should be taken into consideration and more studies should be performed on this issue.

  10. Vitamin D Supplementation in Submariners

    Science.gov (United States)

    2008-12-02

    also known as cholecalciferol . This is a result of the reaction between 7-dehydrocholesterol in the epidermis and ultraviolet radiation in the...skin) (From Diet) Vitamin D3 ( Cholecalciferol ) UV light Vitamin D2 (Ergocalciferol) Liver 25-Hydroxy Vitamin D (Calcidiol) Kidney 1,25-Dihydroxy...monthly oral vitamin D3 ( cholecalciferol ) supplementation on fractures and mortality in men and women living in the community: randomized double

  11. [Vitamin D and cardiovascular risk].

    Science.gov (United States)

    Mayer, Otto

    2012-05-01

    The pathogenesis of cardiovascular disease is without any doubt multifactorial, and it is generally accepted, that conventional risk factors determined only about 80% of cardiovascular risk. There is accumulating evidence that vitamin D exerts important pathophysiological effects on cardiovascular system. Low vitamin D was associated with increased cardiovascular risk in several reports. This review summarizes recent epidemiological evidence and possible pathophysiological mechanism for a role of low vitamin D in cardiovascular diseases. Moreover, available data concerning vitamin D supplementation are depicted.

  12. Vitamin D and Cardiovascular Disease

    OpenAIRE

    Grübler, Martin R.; Martin Gaksch; Thomas Pieber; Katharina Kienreich; Nicolas Verheyen; Andreas Tomaschitz; Stefan Pilz

    2013-01-01

    Vitamin D deficiency, as well as cardiovascular diseases (CVD) and related risk factors are highly prevalent worldwide and frequently co-occur. Vitamin D has long been known to be an essential part of bone metabolism, although recent evidence suggests that vitamin D plays a key role in the pathophysiology of other diseases, including CVD, as well. In this review, we aim to summarize the most recent data on the involvement of vitamin D deficiency in the development of major cardiovascular risk...

  13. Electrochromic Device with Polymer Electrolyte

    Science.gov (United States)

    Solovyev, Andrey A.; Zakharov, Alexander N.; Rabotkin, Sergey V.; Kovsharov, Nikolay F.

    2016-08-01

    In this study a solid-state electrochromic device (ECD) comprised of a WO3 and Prussian blue (Fe4[Fe(CN)6]3) thin film couple with a Li+-conducting solid polymer electrolyte is discussed. WO3 was deposited on K-Glass substrate by magnetron sputtering method, while Prussian blue layer was formed on the same substrate by electrodeposition method. The parameters of the electrochromic device K-Glass/WO3/Li+-electrolyte/PB/K-Glass, such as change of transmittance, response time and stability were successfully tested using coupled optoelectrochemical methods. The device was colored or bleached by the application of +2 V or -2 V, respectively. Light modulation with transmittance variation of up to 59% and coloration efficiency of 43 cm2/C at a wavelength of 550 nm were obtained. Numerous switching of the ECD over 1200 cycles without the observation of significant degradation has been demonstrated.

  14. Composite electrode/electrolyte structure

    Science.gov (United States)

    Visco, Steven J.; Jacobson, Craig P.; DeJonghe, Lutgard C.

    2004-01-27

    Provided is an electrode fabricated from highly electronically conductive materials such as metals, metal alloys, or electronically conductive ceramics. The electronic conductivity of the electrode substrate is maximized. Onto this electrode in the green state, a green ionic (e.g., electrolyte) film is deposited and the assembly is co-fired at a temperature suitable to fully densify the film while the substrate retains porosity. Subsequently, a catalytic material is added to the electrode structure by infiltration of a metal salt and subsequent low temperature firing. The invention allows for an electrode with high electronic conductivity and sufficient catalytic activity to achieve high power density in ionic (electrochemical) devices such as fuel cells and electrolytic gas separation systems.

  15. Electrolyte leakage as an indicator

    Directory of Open Access Journals (Sweden)

    ahmad nezami

    2009-06-01

    Full Text Available In order to evaluate the electrolyte leakage as an indicator of freezing injury in colza (Brassica napus L. genotypes under controlled conditions, a trial carried out at the green house of College of Agriculture, Ferdowsi University of Mashhad. In this study 10 rapeseed genotypes, with 5 temperatures (0, -4, -8, -12 and -16 °C on subplot and acclimation and non acclimation on main plot were evaluated on RCD factorial split plot with two replications. Plants were kept until 3-5 leaf stage in green house condition with 23/16 2 °C (day/night and natural photoperiod. Pots were subjected to acclimation (for three weeks or non acclimation that plants immediately frozen.For acclimation treatment after three weeks freezing was done in thermogradient freezer. The cell membrane integrity was measured through electrolyte leakage and the lethal temperature 50 (LT50 of samples also were determined. There were significant differences (p

  16. New Polymer Electrolyte Cell Systems

    Science.gov (United States)

    Smyrl, William H.; Owens, Boone B.; Mann, Kent; Pappenfus, T.; Henderson, W.

    2004-01-01

    PAPERS PUBLISHED: 1. Pappenfus, Ted M.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; Smyrl, William H. Complexes of Lithium Imide Salts with Tetraglyme and Their Polyelectrolyte Composite Materials. Journal of the Electrochemical Society (2004), 15 1 (2), A209-A2 15. 2. Pappenfus, Ted M.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; Smyrl, William H. Ionic-liquidlpolymer electrolyte composite materials for electrochemical device applications. Polymeric Materials Science and Engineering (2003), 88 302. 3. Pappenfus, Ted R.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; and Smyrl, William H. Ionic Conductivity of a poly(vinylpyridinium)/Silver Iodide Solid Polymer Electrolyte System. Solid State Ionics (in press 2004). 4. Pappenfus Ted M.; Mann, Kent R; Smyrl, William H. Polyelectrolyte Composite Materials with LiPFs and Tetraglyme. Electrochemical and Solid State Letters, (2004), 7(8), A254.

  17. Stability and plasticizing and crystallization effects of vitamins in amorphous sugar systems.

    Science.gov (United States)

    Zhou, Yankun; Roos, Yrjö H

    2012-02-01

    Increased molecular mobility and structural changes resulting from water plasticization of glassy solids may lead to loss of the entrapped compounds from encapsulant systems. In the present study, the stability of water-soluble vitamins, vitamin B(1) (vB(1), thiamin hydrochloride) and vitamin C (vC, ascorbic acid), in freeze-dried lactose and trehalose at various water activities was studied. Water sorption of lactose-vB(1), lactose-vC, trehalose-vB(1), and trehalose-vC systems was determined gravimetrically. Glass transition and crystallization of anhydrous and plasticized sugar-vitamin systems were determined using thermal analysis. Critical water activity was calculated using water sorption and glass transition data. The retention of the vitamins was measured spectrophotometrically. The results showed that the amorphous structure protected the entrapped vitamins at low a(w). Crystallization of lactose accelerated vitamin degradation, whereas trehalose retained much higher amounts of the vitamins. Glass transition and critical water activity of solids and crystallization of component sugars should be considered in the stabilization of sensitive components.

  18. Application of Proton Conduction Boehmite Electrolyte to Single Chamber Fuel Cell

    Science.gov (United States)

    Kimura, Takeshi; Nagata, Akiyoshi

    The power generation characteristic at room temperature of a single chamber fuel cell using a novel hydrated aluminium oxide, pseudoboehmite (pb) proton conductor as the electrolyte was studied based on dependence on the crystal structure and treatment temperature of pb electrolytes generated by the hot water treatment of Al and Al2O3 films evaporated on the glass substrate. A single fuel cell using the pb electrolyte could be fabricated in various gas mixtures of hydrogen and oxygen at room temperature. Maximum open circuit voltage was obtained at a fuel cell using pb electrolytes generated by the soak treatment of Al and Al2O3 films during 4 hours in the hot water of 90°C.

  19. Increasing the performance of tritium analysis by electrolytic enrichment.

    Science.gov (United States)

    Groning, M; Auer, R; Brummer, D; Jaklitsch, M; Sambandam, C; Tanweer, A; Tatzber, H

    2009-06-01

    Several improvements are described for the existing tritium enrichment system at the Isotope Hydrology Laboratory of the International Atomic Energy Agency for processing natural water samples. The improvements include a simple method for pretreatment of electrolytic cells to ensure a high tritium separation factor, an improved design of the exhaust system for explosive gases, and a vacuum distillation line for faster initial preparation of water samples for electrolytic enrichment and for tritium analysis. Achievements included the reduction of variation of individual enrichment parameters of all cells to less than 1% and an improvement of 50% of the stability of the background mean. It resulted in an improved detection limit of less than 0.4 TU (at 2s), important for application of tritium measurements in the future at low concentration levels, and resulted in measurement precisions of+/-0.2 TU and+/-0.15 TU for liquid scintillation counting and for gas proportional counting, respectively.

  20. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... for which low dietary intake may be a cause of concern. These nutrients are: calcium, potassium, fiber, magnesium, and vitamins A (as carotenoids), C, and E (for adults) calcium, potassium, fiber, magnesium, and vitamin E (for children and adolescents) vitamin B-12, iron, folic acid, ...

  1. 25-hydroxy vitamin D test

    Science.gov (United States)

    25-OH vitamin D test; Calcidiol; 25-hydroxycholecalciferol test ... if you have too much or too little vitamin D in your blood. ... The normal range of vitamin D is measured as nanograms per milliliter (ng/mL). Many experts recommend a level between 20 and 40 ng/mL. ...

  2. Vitamin D and Breast Cancer

    NARCIS (Netherlands)

    T. Vink-Van Wijngaarden (Trudy)

    1995-01-01

    textabstractVitamin D regulates calcium and phosphorus blood levels and bone metabolism via effects on intestine, kidney, and bone. Vitamin D is formed from 7-dehydrocholesterol in the skin by ultraviolet irradiation or is taken up from dietary sources. Vitamin D must be metabolically altered

  3. Vitamin D and Your Child

    Science.gov (United States)

    ... may not get enough sun to meet their vitamin D needs. People with dark skin. Because the pigment, or melanin, in darker skin ... IU of vitamin D each day. Most commonly, vitamin D deficiency affects kids with darker skin and those who live in northern regions with ...

  4. Vitamin D and Breast Cancer

    NARCIS (Netherlands)

    T. Vink-Van Wijngaarden (Trudy)

    1995-01-01

    textabstractVitamin D regulates calcium and phosphorus blood levels and bone metabolism via effects on intestine, kidney, and bone. Vitamin D is formed from 7-dehydrocholesterol in the skin by ultraviolet irradiation or is taken up from dietary sources. Vitamin D must be metabolically altered succes

  5. Fortify Your Knowledge about Vitamins

    Medline Plus

    Full Text Available ... calcium, potassium, fiber, magnesium, and vitamin E (for children and adolescents) vitamin B-12, iron, folic acid, and vitamins E and D (for ... C (ascorbic acid): Upset stomach, kidney stones, increased iron ... signs of B-12 deficiency, a condition that can cause nerve damage Taking ...

  6. Effects of electrolytes on ion transport in Chitosan membranes

    Science.gov (United States)

    Rupiasih, N. N.

    2016-11-01

    Recently, charged polymer membranes are widely used for water purification applications involving control of water and ion transport, such as reverse osmosis and electrodialysis. In this study, we have explored the effects of electrolyte solutions on ion transport properties of chitosan synthetic membranes via concentration gradient driven transport. Also, the water uptake of those membranes, before (control) as well used membranes have studied. The membrane used was chitosan membrane 2%. The electrolyte solutions used were HCl, KCl, CaCl2, MgCl2 and AlCl3, with various concentrations of 0.1 mM, 1 mM, 10 mM, 100 mM and 1000 mM. Ion transport experiments were carried out in a cell membrane model which composed of two compartments and the potential difference of membrane was measured using Ag/AgCl calomel electrodes. Those measurements were conducted at ambient temperature 28.8 °C. The results showed that the current density (J) increased with increased in concentration gradient of solution. The current density was higher in electrolyte solution which has higher molar conductivity than those of a solution with a small molar conductivity. Meanwhile the current density was smaller in electrolyte solution which has larger Stokes radii than those of a solution with small Stokes radii. Except membrane which has been used in HCl solution, the water uptakes of the used membranes were greater than the control membrane. These results can develop and validate a common framework to interpret data of concentration gradient driven transport in chitosan synthetic membranes and to use it to design of membranes with improved performance.

  7. Premiminary tests on modified clays for electrolyte contaminated drilling fluids

    OpenAIRE

    den Hamer, Davina; Di Emidio, Gemmina; Bezuijen, Adam; Verastegui Flores, Daniel

    2015-01-01

    The quality of a bentonite suspension declines in aggressive systems like brackish or saline pore water. An engineered clay (HYPER clay) was developed for sealing materials with enhanced resistance to aggressive conditions. The modified clay is produced by treating a sodium activated bentonite with a cellulose polymer following the HYPER clay process method. This study investigates the suitability of the modified clay for electrolyte contaminated drilling fluids. Drilling fluids become contam...

  8. Experimental Investigation into the Transmembrane Electrical Potential of the Forward Osmosis Membrane Process in Electrolyte Solutions

    OpenAIRE

    Lixia Bian; Yanyan Fang; Xiaolin Wang

    2014-01-01

    The transmembrane electrical potential (TMEP) in a forward osmosis membrane process with a single electrolyte solution as the draw and feed solutions was investigated by experiments. The effects of membrane orientation, the electrolyte species (KCl, NaCl, MgCl2, and CaCl2), concentration and concentration ratio of solutions at both sides of membrane on water flux and TMEP were investigated. The results showed that the TMEPs at different membrane orientation cannot completely coincide, which c...

  9. Nafion and modified-Nafion membranes for polymer electrolyte fuel cells: An overview

    Indian Academy of Sciences (India)

    A K Sahu; S Pitchumani; P Sridhar; A K Shukla

    2009-06-01

    Polymer electrolyte fuel cells (PEFCs) employ membrane electrolytes for proton transport during the cell reaction. The membrane forms a key component of the PEFC and its performance is controlled by several physical parameters, viz. water up-take, ion-exchange capacity, proton conductivity and humidity. The article presents an overview on Nafion membranes highlighting their merits and demerits with efforts on modified-Nafion membranes.

  10. Treatment of malabsorption vitamin D deficiency myopathy with intramuscular vitamin D.

    Science.gov (United States)

    Alyaarubi, Saif; Rodd, Celia

    2005-07-01

    A nearly 5 year-old boy presented with proximal muscle weakness, reduced muscle bulk, a positive Gower sign and Trendelenburg gait. He was known to have cholestatic liver disease. Investigations revealed markedly low serum total calcium, elevated alkaline phosphatase, very low serum 25-hydroxyvitamin D, and radiographs consistent with active rickets despite the ongoing administration of a water-soluble preparation of vitamin D. Only i.v. calcitriol acutely corrected the hypocalcemia, despite trying several oral preparations, suggesting that malabsorption secondary to chronic liver disease was the cause of his rickets. Intramuscular calciferol quickly corrected his muscle weakness and X-ray findings. Myopathy secondary to vitamin D deficiency is an uncommon diagnosis in children. Intermittent calciferol is an inexpensive and practical treatment for vitamin D deficiency, especially if associated with malabsorption.

  11. Colorimetric determination of tocopheryl acetate (vitamin E) in pure form and in multi-vitamin capsules.

    Science.gov (United States)

    Amin, A S

    2001-05-01

    A simple, accurate and sensitive method for the determination of micro amounts of vitamin E (V(E)) in pure form and in multi-vitamin capsules is described. The method is based on the reduction of tetrazolium blue in slightly alkaline medium by vitamin E after extraction from aqueous EDTA medium with petroleum ether and transesterification. The oxidation reduction reaction occurs after 10 min of heating in a water bath at 90+/-2 degrees C, leading to the formation of a highly coloured formazan derivative. Different variables affecting the colour development were investigated and optimized. Absorbance measurements were made at 526 nm and the calibration graph was linear for 0.2-11.0 microg/ml of (V(E)) with relative precision of about 0.7-1.5% when the standard additions method is used.

  12. Incidence of vitamin deficiency after laparoscopic Roux-en-Y gastric bypass in a university hospital setting.

    Science.gov (United States)

    Clements, Ronald H; Katasani, Venkata G; Palepu, Rajendra; Leeth, Ruth R; Leath, Teresa D; Roy, Brandon P; Vickers, Selwyn M

    2006-12-01

    Vitamin deficiency after gastric bypass surgery is a known complication. The purpose of this study was to measure the incidence of vitamin deficiency after laparoscopic Roux-en-Y gastric bypass in a university hospital setting. All patients who underwent laparoscopic Roux-en-Y gastric bypass from January 2002 to December 2004 and completed a 1- and 2-year follow-up after surgery were selected. Of the total 493 patients, 318 (65%) had vitamin results at 1-year follow-up. Of the 366 eligible for the 2-year follow-up, 141 (39%) had vitamin results. Patients were further grouped based on gender, race, and Roux limb length, and incidence of vitamin deficiencies were studied. The incidence of vitamin A (retinol) deficiency was 11 per cent, vitamin C was 34.6 per cent, vitamin D25OH was 7 per cent, vitamin B1 was 18.3 per cent, vitamin B2 was 13.6 per cent, vitamin B6 was 17.6 per cent, and vitamin B12 was 3.6 per cent 12 months after surgery. There was no statistical difference in the incidence of vitamin deficiencies between 1 and 2 years. In univariate and multivariate logistic regression of 1- and 2-year follow up, black patients (vitamins A, D, and B1 for 1 year and B1 and B6 for 2 years) and women (vitamin C at 1 year) were more likely to have vitamin deficiencies. Vitamin deficiencies after laparoscopic Roux-en-Y gastric bypass are more common and involve more vitamins, even those that are water soluble, than previously appreciated. Black patients tend to have more deficiencies than other groups. The bariatric surgeon should be committed to the long-term follow-up and care of these patients. Further prospective and randomized studies are necessary to provide appropriate guidelines for supplementation.

  13. Arsenic Exposure from Drinking Water, Dietary Intakes of B Vitamins and Folate, and Risk of High Blood Pressure in Bangladesh: A Population-based, Cross-sectional Study

    National Research Council Canada - National Science Library

    Chen, Yu; Factor-Litvak, Pam; Howe, Geoffrey R; Graziano, Joseph H; Brandt-Rauf, Paul; Parvez, Faruque; van Geen, Alexander; Ahsan, Habibul

    The authors performed a cross-sectional analysis to evaluate the association between arsenic exposure from drinking water and blood pressure using baseline data of 10,910 participants in the Health...

  14. Extraskeletal effects of vitamin D

    Directory of Open Access Journals (Sweden)

    Maurizio Rossini

    2011-04-01

    Full Text Available In the last years we observed an increasing number of publications about the vitamin D, due to its recognised therapeutic actions and to the widespread hypovitaminosis D. In addition to the well known skeletal benefits, vitamin D can have multiple effects on other tissues.Muscular apparatus: hypovitaminosis D is associated with myopathy, sarcopenia, muscular strength reduction and increased risk of falls. The vitamin D supplementation increases the muscle functionality indexes. Cardiovascular system: low levels of vitamin D are related to increased levels of cardiovascular risk factors, heart failure, stroke, and cardiovascular mortality, while a good vitamin D status is associated with a decreased incidence of cardiovascular diseases. Diabetes and metabolic syndrome: a good vitamin D status is related to a decreased incidence of type 2 diabetes and metabolic syndrome; a vitamin D supplementation in the early childhood reduces (nearly 30% the risk of having type 1 diabetes. Cancer: vitamin D deficit is associated with breast, colorectal cancer and melanoma relapses. Low and high levels of 25-hydroxy-vitamin D (25(OHD are related to a higher neoplastic mortality. Infectious diseases: hypovitaminosis D is associated with higher incidence of upper respiratory tract infections and worse interferon response in chronic hepatitis C. Vitamin D supplementation decreases the risk of having type A influence. Rheumatic diseases: in rheumatoid arthritis low serum levels of vitamin D metabolites are related to a higher disease activity, while a good vitamin D status is associated with a higher probability of remission or response to therapy and a lower degree of disability. Neurologic diseases: associations between vitamin D deficit and risk of multiple sclerosis, depression, cognitive deficits, and Parkinson’s disease have been reported.There is evidence of the extraskeletal effects of vitamin D, but most derive from observational studies: clinical trials

  15. Validation of a High-Performance Liquid Chromatography method for the determination of vitamin A, vitamin D3, vitamin E and benzyl alcohol in a veterinary oily injectable solution

    Directory of Open Access Journals (Sweden)

    Maria Neagu

    2015-06-01

    Full Text Available A new simple, rapid, accurate and precise high – performance liquid chromatography (HPLC method for determination of vitamin A, vitamin D3, vitamin E and benzyl alcohol in oily injectable solution was developed and validated. The method can be used for the detection and quantification of known and unknown impurities and degradants in the drug substance during routine analysis and also for stability studies in view of its capability to separate degradation products. The method was validated for accuracy, precision, specificity, robustness and quantification limits according to ICH Guidelines. The estimation of vitamin A, vitamin D3, vitamin E and benzyl alcohol was done by Waters HPLC system manager using gradient pump system. The chromatographic conditions comprised a reverse-phased C18 column (5 µm particle size, 250 mm×4.6 mm i.d. with a mobile phase consisting of tetrahydrofurane, acetonitrile and water in gradient elution. The flow rate was 0.8 ml/min and 2.0 ml/min. Standard curves were linear over the concentration range of 16.50 µg/ml to 11.00 mg/ml for vitamin A, 10.05 µg/ml to 6.70 mg/ml for vitamin E, 0.075 µg/ml to 0.050 mg/ml for vitamin D3 and 1.25 mg/ml to 5.00 mg/ml for benzylalcohol. Statistical analyses proved the method was precise, reproducible, selective, specific and accurate for analysis of vitamin A, vitamin D3, vitamin E, benzyl alcohol and impurities.

  16. Electrochemical behavior of PEDOT/Lignin in Ionic Liquid Electrolytes: Suitable Cathode/Electrolyte System for Sodium Batteries.

    Science.gov (United States)

    Casado, Nerea; Hilder, Matthias; Pozo-Gonzalo, Cristina; Forsyth, Maria; Mecerreyes, David

    2017-02-15

    Biomass derived polymers, such as lignin, contain redox quinone/hydroquinone redox moieties that can be used to store charge. Composites based on the biopolymer lignin and several conjugated polymers have shown good charge storage properties. However, their performance has been just studied in acidic aqueous media limiting the applications mainly to supercapacitors. Here we show that PEDOT/Lignin biopolymers are electroactive in aprotic ionic liquids and we move a step further by assembling sodium full cell batteries using PEDOT/Lignin as electrode material and ionic liquid electrolytes. Thus, the electrochemical activity and cycling of PEDOT/Lignin electrodes is investigated in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPyrTFSI), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (BMPyrFSI), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMImTFSI) and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMImFSI) ionic liquid electrolytes. The effects of water and sodium salt addition to the ionic liquids are investigated in order to obtain optimum electrolyte systems for sodium batteries. Finally, sodium batteries based on PEDOT/Lignin cathode with imidazolium based ionic liquid electrolyte showed higher capacity values than pyrrolidinium ones, reaching 70 mAhg-1. Our results demonstrate that PEDOT/Lignin composites can serve as low cost and sustainable cathode materials for sodium batteries.

  17. Vitamin D-enhanced duodenal calcium transport.

    Science.gov (United States)

    Wongdee, Kannikar; Charoenphandhu, Narattaphol

    2015-01-01

    For humans and rodents, duodenum is a very important site of calcium absorption since it is exposed to ionized calcium released from dietary complexes by gastric acid. Calcium traverses the duodenal epithelium via both transcellular and paracellular pathways in a vitamin D-dependent manner. After binding to the nuclear vitamin D receptor, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] upregulates the expression of several calcium transporter genes, e.g., TRPV5/6, calbindin-D9k, plasma membrane Ca(2+)-ATPase1b, and NCX1, thereby enhancing the transcellular calcium transport. This action has been reported to be under the regulation of parathyroid-kidney-intestinal and bone-kidney-intestinal axes, in which the plasma calcium and fibroblast growth factor-23 act as negative feedback regulators, respectively. 1,25(OH)2D3 also modulates the expression of tight junction-related genes and convective water flow, presumably to increase the paracellular calcium permeability and solvent drag-induced calcium transport. However, vitamin D-independent calcium absorption does exist and plays an important role in calcium homeostasis under certain conditions, particularly in neonatal period, pregnancy, and lactation as well as in naturally vitamin D-impoverished subterranean mammals.

  18. Vitamin K and Hemostasis - Review

    Directory of Open Access Journals (Sweden)

    Fatih Demirtaş

    2010-12-01

    Full Text Available Vitamin K is necessary for the synthesis of the proteins that help control bleeding (clotting factors and thus for the normal clotting of blood. Newborns are prone to vitamin K deficiency because only small amounts of vitamin K cross the placenta and because, during the first few days after birth, their intestine does not contain bacteria to produce vitamin K. The deficiency can cause hemorrhagic disease of the newborn, characterized by a tendency to bleed. A vitamin K injection in the muscle is recommended for all newborns to reduce the risk of bleeding within the brain after delivery. (Journal of Current Pediatrics 2010; 8: 113-8

  19. Vitamin D and Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Özlem Turhan İyidir

    2012-12-01

    Full Text Available Recent epidemiological data have established a link between vitamin D deficiency and type 1 and type 2 diabetes mellitus (DM. Experimental evidence also supported the idea that vitamin D may play a role in the pathogenesis of DM. Additionally, it has been reported that vitamin D supplementation may decrease the risk of developing DM in long term period. The protective effects of vitamin D are mediated through the immune system and calcium metabolism. Vitamin D may also have a direct effect on pancreatic beta cells. Turk Jem 2012; 16: 89-94

  20. [Vitamin D and infectious diseases].

    Science.gov (United States)

    Ghosn, Jade; Viard, Jean-Paul

    2013-10-01

    Vitamin D plays a role in the synthesis of antibacterial peptids and in autophagy. Several studies have shown that low levels of vitamin D are associated with the susceptibility and the severity of acute infections on one hand, and with an unfavorable outcome of some chronic infections (such as HIV infection). Vitamin D supplementation improves response to treatment of some viral (such as chronic hepatitis C infection) or bacterial infections (such as pulmonar tuberculosis). Vitamin D supplementation demonstrated no benefit in reducing the incidence of pulmonary infections. The target level of vitamin D to be reached after supplementation is not known yet.