WorldWideScience

Sample records for boric acids

  1. Recovery of boric acid from ion exchangers

    International Nuclear Information System (INIS)

    Pollock, C.W.

    1976-01-01

    The recovery of boric acid from an anion exchange resin is improved by eluting the boric acid with an aqueous solution of ammonium bicarbonate. The boric acid can be readily purified and concentrated by distilling off the water and ammonium bicarbonate. This process is especially useful for the recovery of boric acid containing a high percentage of 10 B which may be found in some nuclear reactor coolant solutions. 10 claims

  2. Boric Acid Reclamation System (BARS)

    International Nuclear Information System (INIS)

    Kniazewycz, B.G.; Markind, J.

    1986-01-01

    KLM Technologies was recently awarded a contract by the Department of Energy for a Phase II demonstration of an optimized full-scale prototype membrane system including performance evaluation under plant operating conditions. The program will serve as the catalyst for developing technology to augment the industry's incentive toward innovative and compact volume reduction alternatives for PWRs. The development and demonstration of the KLM Boric Acid Reclamation System, which is readily retrofitted into existing PWR facilities, will provide a positive means of reducing PWR waste volumes without requiring the $25-50 million equipment and support facility expenditures associated with most liquid waste volume reduction systems. This new application for membrane separation technology can reduce waste by upward of 50 percent for two-thirds of the operating nuclear plants in the U.S. The use of membrane technology has demonstrated significant process potential in radwaste and related applications. Reverse Osmosis (RO) and Ultrafiltration (UF) can provide selective filtration capability and concentrate contaminants without the need of filter aids, thus minimizing the requirements of chemical regeneration, costly resins, and major process equipment with large auxiliary heat supplies. KLM Technologies' personnel have identified a Boric Acid Reclamation System (BARS) utilizing RO and UF to produce a recyclable grade of otherwise waste boric acid at PWRs, thus reducing a major source of low-level radwaste. The design of a prototype BARS as a compact volume reduction system was the result of KLM's Phase I Program, and based upon a preliminary feasibility program, which assessed the applicability of membrane technology to refurbish and recycle waste boric acid from floor and equipment drain streams. The analysis of the overall program indicated a substantial savings regarding off-site disposal costs

  3. Boric Acid Reclamation System (BARS)

    International Nuclear Information System (INIS)

    Kniazewycz, B.G.; Markind, J.

    1986-03-01

    KLM Technologies' personnel have identified a Boric Acid Reclamation System (BARS) utilizing reverse osmosis and ultrafiltration to produce a recyclable grade of otherwise waste boric acid at PWRs, thus reducing a major source of low-level radwaste. The design of a prototype BARS as a compact volume reduction system was the result of KLM's Phase 1 Program, and based upon a preliminary feasibility program, which assessed the applicability of membrane technology to refurbish and recycle waste boric acid from floor and equipment drain streams. The analysis of the overall program indicated a substantial savings regarding off-site disposal costs. Today's economic scenario indicates that optimization of volume reduction operation procedures could significantly reduce waste management costs, especially where burial penalties have become more severe. As a reaction to the economic burden imposed by final disposal, many nuclear plants are currently modifying their design and operating philosophies concerning liquid radwaste processing systems to meet stricter environmental regulations, and to derive potential economic benefits by reducing the ever-increasing volumes of wastes that are produced. To effect these changes, innovative practices in waste management and more efficient processing technologies are being successfully implemented

  4. MCB-2 concentration meter for boric acid

    International Nuclear Information System (INIS)

    Lisecki, W.

    1978-01-01

    The principles are explained of the thermal neutron absorption method for monitoring boric acid concentration in the WWER type reactor coolant. The design principles and the characteristics of four variants are described of the MSB-2 type boric acid concentration monitor developed by IBJ. (B.S.)

  5. Recovery of boric acid from nuclear waste

    International Nuclear Information System (INIS)

    Lahoda, E.J.

    1985-01-01

    Disclosed is a process for separating and recovering boric acid from water containing solids which include boric acid and radionuclides. In the first step, the water is separated from the solids by evaporation of the water at a temperature under 130 0 F In the second step, an alcohol selected from the group consisting of methanol, ethanol, propanol, isopropanol, and mixtures thereof is added to the remaining solids in the amount of at least 1.4 times that stoichiometrically required to react with the boric acid to form boron alkoxide and water to about 100 mole % in excess of stoichiometric. In the third step, the boron alkoxide is separated from the remaining solids by evaporation of the boron alkoxide. In the fourth step, water is added to the volatilized boron alkoxide to form boric acid and an alcohol. And finally, the alcohol is separated from the boric acid by evaporating the alcohol

  6. LITERATURE REVIEW OF BORIC ACID SOLUBILITY DATA

    Energy Technology Data Exchange (ETDEWEB)

    Crapse, K.; Kyser, E.

    2011-09-22

    A new solvent system is being evaluated for use in the Modular Caustic-Side Solvent Extraction Unit (MCU) and in the Salt Waste Processing Facility (SWPF). The new system replaces the current dilute nitric acid strip solution with 0.01 M boric acid. This literature study is performed to determine if there is a potential for boric acid to crystallize in the lines with emphasis on the transfer lines to the Defense Waste Processing Facility. This report focuses on the aqueous phase chemistry of boric acid under conditions relevant to MCU and SWPF. Operating and transfer conditions examined for the purpose of this review include temperatures between 13 C (McLeskey, 2008) and 45 C (Fondeur, 2007) and concentrations from 0 to 3M in nitric acid as well as exposure of small amounts of entrained boric acid in the organic phase to the sodium hydroxide caustic wash stream. Experiments were also conducted to observe any chemical reactions and off-gas generation that could occur when 0.01 M boric acid solution mixes with 3 M nitric acid solution and vice versa. Based on the low concentration (0.01M) of boric acid in the MCU/SWPF strip acid and the moderate operating temperatures (13 C to 45 C), it is unlikely that crystallization of boric acid will occur in the acid strip solution under process or transfer conditions. Mixing experiments of boric and nitric acid show no measurable gas generation (< 1 cc of gas per liter of solution) under similar process conditions.

  7. Solubilities of boric acid in heavy water

    International Nuclear Information System (INIS)

    Nakai, Shigetsugu; Aoi, Hideki; Hayashi, Ken-ichi; Katoh, Taizo; Watanabe, Takashi.

    1988-01-01

    A gravimetric analysis using meta-boric acid (HBO 2 or DBO 2 ) as a weighing form has been developed for solubility measurement. The method gave satisfactory results in preliminary measurement of solubilities of boric acid in light water. By using this method, the solubilities of 10 B enriched D 3 BO 3 in heavy water were measured. The results are as follows; 2.67 (7deg C), 3.52 (15deg C), 5.70 (30deg C), 8.87 (50deg C) and 12.92 (70deg C) w/o, respectively. These values are about 10% lower than those in light water. Thermodynamical consideration based on the data shows that boric acid is the water structure breaker. (author)

  8. Evaporation of boric acid from sea water

    Energy Technology Data Exchange (ETDEWEB)

    Gast, J A; Thompson, T G

    1959-01-01

    Previous investigators have shown that the boron-chlorinity ratios of rain waters are many times greater than the boron-chlorinity ratio of sea water. The presence of boron in the atmosphere has been attributed to sea spray, volcanic activity, accumulation in dust, evaporation from plants, and industrial pollution. In this paper data are presented to demonstrate that boric acid in sea water has a vapor pressure at ordinary temperatures of the sea and, when sea water evaporates, boric acid occurs in the condensate of the water vapor. It is postulated that, while some of the boron in the atmosphere can be attributed to the sources mentioned above, most of the boric acid results from evaporation from the sea.

  9. Lubrication from mixture of boric acid with oils and greases

    Science.gov (United States)

    Erdemir, Ali

    1995-01-01

    Lubricating compositions including crystalline boric acid and a base lubricant selected from oils, greases and the like. The lubricity of conventional oils and greases can also be improved by adding concentrates of boric acid.

  10. Boric acid corrosion of low alloy steel

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R.; White, G.; Collin, J.; Marks, C. [Dominion Engineering, Inc., Reston, Virginia (United States); Reid, R.; Crooker, P. [Electric Power Research Inst., Palo Alto, California (United States)

    2010-07-01

    In the last decade, the industry has been aware of a potential loss of coolant accident (LOCA) per the following scenario: primary water stress corrosion cracking (PWSCC) of a primary system component or weld leads to a coolant leak, the coolant corrodes a low alloy steel structural component (e.g., the reactor vessel (RV) or the reactor vessel head (RVH)), and corrosion degrades the pressure boundary leading to a loss of coolant accident. The industry has taken several steps to address this concern, including replacement of the most susceptible components (RVH replacement), enhanced inspection (both NDE of components and visual inspections for boric acid deposits), and safety analyses to determine appropriate inspection intervals. Although these measures are generally thought to have adequately addressed this issue, there have been some uncertainties in the safety analyses which the industry has sought to address in order to quantify the extent of conservatism in the safety analyses. Specifically, there has been some uncertainty regarding the rate of boric acid corrosion under various conditions which might arise due to a PWSCC leak and the extent to which boric acid deposits are retained near the leak under various geometries. This paper reviews the results of the Electric Power Research Institute (EPRI) Materials Reliability Program (MRP) boric acid corrosion (BAC) test programs conducted over the last 8 years, focusing on the most recent results of full-scale mockup testing of CRDM nozzle and bottom mounted nozzle (BMN) configurations. The main purpose of this presentation is to provide an overview of the latest understanding of the risk of boric acid corrosion as it is informed by the results of the testing conducted over the last eight years. The rate of boric acid corrosion has been found to be a function of many factors, including initial chemistry, the extent of concentration due to boiling, the temperature at which concentration takes place, the velocity

  11. Effects of an inorganic insecticide (boric acid) against Blattella ...

    African Journals Online (AJOL)

    In order to obtain more information on the mode of action of boric acid, which has not been satisfactorily established, a biometric and biochemical study of the ovaries was done following the toxicity assays after having evaluated the toxicity of the boric acid against B. germanica. Boric acid was injected at two doses, 77.62 ...

  12. Processing of nuclear power plant waste streams containing boric acid

    International Nuclear Information System (INIS)

    1996-10-01

    Boric acid is used in PWR type reactor's primary coolant circuit to control the neutron flux. However, boric acid complicates the control of water chemistry of primary coolant and the liquid radioactive waste produced from NPP. The purpose of this report is to provide member states with up-to-date information and guidelines for the treatment and conditioning of boric acid containing wastes. It contains chapters on: (a) characteristics of waste streams; (b) options for management of boric acid containing waste; (c) treatment/decontamination of boric acid containing waste; (d) concentration and immobilization of boric acid containing waste; (e) recovery and re-use of boric acid; (f) selected industrial processes in various countries; and (g) the influence of economic factors on process selection. 72 refs, 23 figs, 5 tabs

  13. Boric Acid Corrosion of Concrete Rebar

    Directory of Open Access Journals (Sweden)

    Yang L.

    2013-07-01

    Full Text Available Borated water leakage through spent fuel pools (SFPs at pressurized water reactors is a concern because it could cause corrosion of reinforcement steel in the concrete structure and compromise the integrity of the structure. Because corrosion rate of carbon steel in concrete in the presence of boric acid is lacking in published literature and available data are equivocal on the effect of boric acid on rebar corrosion, corrosion rate measurements were conducted in this study using several test methods. Rebar corrosion rates were measured in (i borated water flowing in a simulated concrete crack, (ii borated water flowing over a concrete surface, (iii borated water that has reacted with concrete, and (iv 2,400 ppm boric acid solutions with pH adjusted to a range of 6.0 to 7.7. The corrosion rates were measured using coupled multielectrode array sensor (CMAS and linear polarization resistance (LPR probes, both made using carbon steel. The results indicate that rebar corrosion rates are low (~1 μm/yr or lesswhen the solution pH is ~7.1 or higher. Below pH ~7.1, the corrosion rate increases with decreasing pH and can reach ~100 μm/yr in solutions with pH less than ~6.7. The threshold pH for carbon steel corrosion in borated solution is between 6.8 and 7.3.

  14. Experimental observations of boric acid precipitation scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Vaghetto, R., E-mail: r.vaghetto@tamu.edu; Childs, M., E-mail: masonchilds@tamu.edu; Jones, P., E-mail: pgjones87@tamu.edu; Lee, S., E-mail: sayalee@tamu.edu; Kee, E., E-mail: erniekee@gmail.com; Hassan, Y.A., E-mail: y-hassan@tamu.edu

    2017-02-15

    During a Loss of Coolant Accident (LOCA) in Light Water Reactors (LWR), borated water is injected into the core through the safety injection system. The continuous vaporization of the water from the core may increase the concentration of boric acid in the core that, under certain conditions may reach the solubility limit and precipitate. This includes scenarios where the liquid water supply to the core is affected by possible blockages due to debris accumulation. Questions have been raised on the effects of the precipitate in the core on the flow behavior, including the possibility of additional blockages produced by precipitate accumulation. A simple experimental facility was constructed to perform experimental observations of the behavior of borated water under the combined effects of the boiling and the boric acid precipitation (BAP). The facility consists of a transparent polycarbonate vertical pipe where forty-five heated rods have been installed to supply the power to the water to reach the saturation temperature, and maintain a desired boil-off rate. The layout and geometry of the experimental apparatus were conceived to emulate a simplified core of a Pressurized Water Reactor (PWR). Experimental observations have been conducted under two different conditions. Preliminary tests were conducted to observe the behavior of the water and the boric acid precipitate during a boil-off scenario without borated water addition (decreasing water level). During the main test runs, borated water was constantly injected from the top of the test section to maintain a constant mixture level in the test section. Both tests assumed no flow from the bottom of the test section which may be the case of PWR LOCA scenarios in presence of debris-generated core blockage. The observations performed with a set of cameras installed around the test section showed interesting effects of the vapor bubbles on the boric acid precipitate migration and accumulation in the test section. The

  15. Ion exchange separation of low boric acid concentrations from water

    International Nuclear Information System (INIS)

    Kysela, J.; Brabec, J.; Peterka, F.

    1975-01-01

    Boric acid poisoning of the moderator of the TR-O experimental heavy water reactor was studied. The possibility is discussed of removing boric acid from heavy water by means of a strong basic anion exchanger, below the residual concentration of 0.01 mg B/l. Measurements of the usable capacities of the strong basic anion exchanger Zerollit FF showed that the penetration of boric acid during the sorption period does not exceed the value of 0.015 mg B/l. The dependence was found of capacity on the boric acid concentration in the solution. Analytical methods used to determine B in water are also described. (author)

  16. Study of boric acid sorption and desorption processes

    International Nuclear Information System (INIS)

    Czosnowska, B.; Laren, E.

    1978-01-01

    The results are given of the experimental determination of the effect on the boric acid flow and sorption and desorption efficiency of the flow rate of boric acid at different concentrations through an ion exchange column 10.2 cm 2 in cross section. The strongly alkaline VOFATIT RO ion exchanger was used. (B.S.)

  17. Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Motahareh Soltani

    2016-08-01

    Full Text Available Objectives: Aluminium phosphide (AlP is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3, a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. Methods: This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Results: Activated charcoal significantly reduced the volume of released gas (P <0.01. Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01. A gaseous adduct was formed in the reaction between pure AlP and boric acid. Conclusion: These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning.

  18. Spectrophotometric determination of boric acid in boron powder with curcumin

    International Nuclear Information System (INIS)

    Grotheer, E.W.

    1979-01-01

    A rapid and accurate method was needed to determine trace amounts of boric acid for quality control and specification testing of elemental boron. The reaction between boric acid and curcumin occurs at a measurable rate only when the curcumin molecule is protonated. Protonation takes place at the carbonyl groups in the presence of a strong acid and occurs completely and rapidly when sulfuric acid is added to a solution of curcumin in acetic acid. Spectrophotometric measurements were made. The extraction of boric acid from boron powder was found to be complete within 2h when either water or the diol solution was used. Whatman No. 40 cr 42 filter paper was used to obtain diol samples free of boron particles. The extraction efficiency of 2-ethyl-1,3-hexanediol was evaluated by adding 1 ml of 500 ppM aqueous boric acid and 1 drop of 10% NaOH to accurately weighed samples of boron powder. The water then was evaporated at room temperature and the samples were extracted with diol solution. The data obtained are included. The extraction efficiency also was evaluated by determining the boric acid content of boron which had been recovered from a previous extraction and boric acid determination. The determination of boric acid using curcumin is unaffected by the presence of other compounds, except for fluoride and nitrate ions. 2 tables

  19. Boric acid solubility in the presence of alkali metal nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Skvortsov, V G; Tsekhanskij, R S; Molodkin, A K; Sadetdinov, Sh V [Chuvashskij Gosudarstvennyj Univ., Cheboksary (USSR); Universitet Druzhby Narodov, Moscow (USSR))

    1983-01-01

    Methods of solubility and refractometry at 25 deg C have been applied to state that systems boric acid-lithium (sodium, potassium) nitrite-water are simple eutonic type systems. Nitrites salt in the acid and their lyotropic effect increases from lithium salt to potassium salt. The disclosed succession in change of the effect is determined by the character of cation hydration in the medium the acidic reaction of which is conditioned by boric acid polymerization and partial oxidation of nitrite ion into nitrate ion. Boric acid is salted out from solutions containing lithium and sodium cations with increase of nitrate ion.

  20. Boric acid solubility in the presence of alkali metal nitrides

    International Nuclear Information System (INIS)

    Skvortsov, V.G.; Tsekhanskij, R.S.; Molodkin, A.K.; Sadetdinov, Sh.V.

    1983-01-01

    Methods of solubility and refractometry at 25 deg C have been applied to state that systems boric acid-lithium (sodiUm, potassium) nitrite-water are simple eutonic type systems. Nitrites salt in the acid and their lyotropic effect increases from lithium salt to potassium salt. The disclosed succession in change of the effect is determined by the character of cation hydration in the medium the acidic reaction of which is conditioned by boric acid polymerization and partial oxidation of nitrite ion into nitrate ion Boric acid is salted out form solutions containing lithium and sodium cations with increase of nitrate ion

  1. Aqueous Boric acid injection facility of PWR type reactor

    International Nuclear Information System (INIS)

    Matsuoka, Tsuyoshi; Iwami, Masao.

    1996-01-01

    If a rupture should be caused in a secondary system of a PWR type reactor, pressure of a primary coolant recycling system is lowered, and a back flow check valve is opened in response to the lowering of the pressure. Then, low temperature aqueous boric acid in the lower portion of a pressurized tank is flown into the primary coolant recycling system based on the pressure difference, and the aqueous boric acid reaches the reactor core together with coolants to suppress reactivity. If the injection is continued, high temperature aqueous boric acid in the upper portion boils under a reduced pressure, further urges the low temperature aqueous boric acid in the lower portion by the steam pressure and injects the same to the primary system. The aqueous boric acid stream from the pressurized tank flowing by self evaporation of the high temperature aqueous boric acid itself is rectified by a rectifying device to prevent occurrence of vortex flow, and the steam is injected in a state of uniform stream. When the pressure in the pressurized tank is lowered, a bypass valve is opened to introduce the high pressure fluid of primary system into the pressurized tank to keep the pressure to a predetermined value. When the pressure in the pressurized tank is elevated to higher than the pressure of the primary system, a back flow check valve is opened, and high pressure aqueous boric acid is flown out of the pressurized tank to keep the pressure to a predetermined value. (N.H.)

  2. General corrosion of metallic materials in boric acid environments

    International Nuclear Information System (INIS)

    Gras, J.M.

    1994-05-01

    Certain low-alloy steel components in PWR primary circuit were corroded by leaking water containing boric acid. A number of studies have been performed by manufacturers in the USA and by EDF in France to determine the rate of general corrosion for low-alloy steels in media containing varying concentrations of boric acid. The first part of this paper summarizes the studies performed and indicates how far work has advanced to date in establishing the resistance of stainless steels to general corrosion in concentrated boric acid solutions. The second part of the paper discusses the mechanism of corrosion and proposes a model. Carbon steels and low-alloy steels - carbon steels and low-alloy steels in deaerated diluted boric acid solutions (pH > 4) corrode very slowly ( -1 . (author). 31 refs., 12 figs., 13 tabs

  3. Effects of an inorganic insecticide (boric acid) against Blattella ...

    African Journals Online (AJOL)

    ufuoma

    2013-05-01

    May 1, 2013 ... Data on ovarian .... The overall data suggested an interference of boric acid with the ... solutions as baits for management of German cockroaches .... Comp. Biochem. Physiol. 135C:257-267. Tine S, Aribi N, Soltani N (2011).

  4. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    Science.gov (United States)

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  5. Surface interactions of cesium and boric acid with stainless steel

    International Nuclear Information System (INIS)

    Grossman-Canfield, N.

    1995-08-01

    In this report, the effects of cesium hydroxide and boric acid on oxidized stainless steel surfaces at high temperatures and near one atmosphere of pressure are investigated. This is the first experimental investigation of this chemical system. The experimental investigations were performed using a mass spectrometer and a mass electrobalance. Surfaces from the different experiments were examined using a scanning electron microscope to identify the presence of deposited species, and electron spectroscopy for chemical analysis to identify the species deposited on the surface. A better understanding of the equilibrium thermodynamics, the kinetics of the steam-accelerated volatilizations, and the release kinetics are gained by these experiments. The release rate is characterized by bulk vaporization/gas-phase mass transfer data. The analysis couples vaporization, deposition, and desorption of the compounds formed by cesium hydroxide and boric acid under conditions similar to what is expected during certain nuclear reactor accidents. This study shows that cesium deposits on an oxidized stainless steel surface at temperatures between 1000 and 1200 Kelvin. Cesium also deposits on stainless steel surfaces coated with boric oxide in the same temperature ranges. The mechanism for cesium deposition onto the oxide layer was found to involve the chemical reaction between cesium and chromate. Some revaporization in the cesium hydroxide-boric acid system was observed. It has been found that under the conditions given, boric acid will react with cesium hydroxide to form cesium metaborate. A model is proposed for this chemical reaction

  6. Boric acid inhibits embryonic histone deacetylases: A suggested mechanism to explain boric acid-related teratogenicity

    International Nuclear Information System (INIS)

    Di Renzo, Francesca; Cappelletti, Graziella; Broccia, Maria L.; Giavini, Erminio; Menegola, Elena

    2007-01-01

    Histone deacetylases (HDAC) control gene expression by changing histonic as well as non histonic protein conformation. HDAC inhibitors (HDACi) are considered to be among the most promising drugs for epigenetic treatment for cancer. Recently a strict relationship between histone hyperacetylation in specific tissues of mouse embryos exposed to two HDACi (valproic acid and trichostatin A) and specific axial skeleton malformations has been demonstrated. The aim of this study is to verify if boric acid (BA), that induces in rodents malformations similar to those valproic acid and trichostatin A-related, acts through similar mechanisms: HDAC inhibition and histone hyperacetylation. Pregnant mice were treated intraperitoneally with a teratogenic dose of BA (1000 mg/kg, day 8 of gestation). Western blot analysis and immunostaining were performed with anti hyperacetylated histone 4 (H4) antibody on embryos explanted 1, 3 or 4 h after treatment and revealed H4 hyperacetylation at the level of somites. HDAC enzyme assay was performed on embryonic nuclear extracts. A significant HDAC inhibition activity (compatible with a mixed type partial inhibition mechanism) was evident with BA. Kinetic analyses indicate that BA modifies substrate affinity by a factor α = 0.51 and maximum velocity by a factor β = 0.70. This work provides the first evidence for HDAC inhibition by BA and suggests such a molecular mechanism for the induction of BA-related malformations

  7. Management of Azole-Refractory Candida Species Using Boric Acid

    African Journals Online (AJOL)

    Mgina

    commonly used drugs in the country, the best performance of boric acid envisage the need to update the national ... drugs especially with the azole antifungal groups and are ... Other factors include extensive use of broad spectrum ..... influence not only prescription tendency but .... pharmacokinetics, and antifungal therapy.

  8. Activity of boric acid on German cockroaches: Analysis of residues ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-02-18

    Feb 18, 2009 ... Full Length Research Paper. Activity of ... In a previous study, we have shown that boric ... ing 300 µl of curcumin solution (12.5 mg curcumin, 10 ml acetic acid) ..... Schal C, Chiang AS, Burns EL, Gadot M, Cooper RA (1993).

  9. Effects of boric acid and borax on titanium dioxide genotoxicity.

    Science.gov (United States)

    Turkez, Hasan

    2008-07-01

    Titanium dioxide (TiO(2)) is a potential carcinogenic/mutagenic agent although it is used in many areas including medical industries and cosmetics. Boron (as boric acid and borax) has also well-described biological effects and therapeutic benefits. In a previous study, sister-chromatid exchanges (SCEs) and micronuclei (MN) rates were assessed in control and TiO(2)-treated (1, 2, 3, 5, 7.5 and 10 microm) human whole blood cultures. The results showed that the rates of SCE (at 2, 3, 5, 7.5 and 10 microm) and MN (at 5, 7.5 and 10 microm) formation in peripheral lymphocytes were increased significantly by TiO(2) compared with the controls. The present study also investigated the genetic effects of boric acid and borax (2.5, 5 and 10 microm) on cultures with and without TiO(2) addition. No significant increase in SCE and MN frequencies were observed at all concentrations of boron compounds. However, TiO(2)-induced SCE and MN could be reduced significantly by the presence of boric acid and borax. In conclusion, this study indicated for the first time that boric acid and borax led to an increased resistance of DNA to damage induced by TiO(2). 2008 John Wiley & Sons, Ltd

  10. 40 CFR 180.1121 - Boric acid and its salts, borax (sodium borate decahydrate), disodium octaborate tetrahydrate...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Boric acid and its salts, borax... salts, borax (sodium borate decahydrate), disodium octaborate tetrahydrate, boric oxide (boric anhydride... its salts, borax (sodium borate decahydrate), disodium octaborate tetrahydrate, boric oxide (boric...

  11. The role of boric acid in the Phebus-FP tests

    International Nuclear Information System (INIS)

    Bowsher, B.R.

    1991-12-01

    The data in this report should enable proposed methods for the introduction of boric acid into the Phebus-FP tests to be assessed. Boric acid chemistry is reviewed in the condensed, vapour and aqueous phases. The chemistry of concentrated aqueous solutions of boric acid is complex, involving polyborate species resulting in enhanced acidities. Equations are presented that allow the partition of boric acid between the vapour and aqueous phase to be calculated at different boric acid concentrations. The volatility of boric acid is enhanced significantly in the presence of steam. Equations are given that allow the effective vapour pressure of boric acid to be determined as functions of the water vapour pressure for temperatures in the range from 723 to 1000 o C. These data are confirmed by experimental studies designed to simulate specific aspects of the conditions in the Phebus-FP tests. (author)

  12. The development of precisely analytical method for the concentrated boric acid solution in the NPP systems

    Energy Technology Data Exchange (ETDEWEB)

    Sung, G. B.; Jung, K. H.; Kang, D. W. [KEPRI, Taejon (Korea, Republic of); Park, C. S. [KEPCO, Taejon (Korea, Republic of)

    1999-05-01

    Boric acid is used for reactivity control in nuclear reactors, which frequently results in leftover boric acid. This extra boric acid is stored in boric acid storage tank after the concentration process by boric acid evaporator. Apart from this excess, highly concentrated boric acid is stored in safety-related boric acid storage tank. Accordingly, proper maintenance of these boric acid is one of the greatest safety concerns. The solubility of boric acid decreases with decreasing temperature resulting in its precipitation. Consequently, the temperature of boric acid storage tanks is maintained at high temperature. The following analysis should be also performed at the similar temperature to prevent the formation of boric acid precipitation, which is difficult to achieve affecting the accuracy of analytical results. This paper presents a new sampling and measuring technique that makes up for the difficulties mentioned above and shows several advantages including improved reliability and short analysis time. This method is based on gravimetry and dilution method and is expected to be widely used in field application.

  13. Boric Acid Catalyzed Convenient Synthesis of Benzimidazoles in Aqueous Media

    OpenAIRE

    Poor Heravi, Mohammad Reza; Ashori, Marjan

    2013-01-01

    Synthesis of benzimidazoles has been developed by the o-phenylenediamine with aldehydes using boric acid an efficient catalyst under mild reaction conditions in aqueous media. The product is applicable to aryl and heteroaryl aldehydes. This reaction led to the formation of benzimidazoles new derivatives in good yields. The FT-IR, 19F-NMR, 1H-NMR, 13C-NMR spectra and elemental analysis confirm the structure of compounds.

  14. Boric Acid Catalyzed Convenient Synthesis of Benzimidazoles in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Poor Heravi

    2013-01-01

    Full Text Available Synthesis of benzimidazoles has been developed by the o-phenylenediamine with aldehydes using boric acid an efficient catalyst under mild reaction conditions in aqueous media. The product is applicable to aryl and heteroaryl aldehydes. This reaction led to the formation of benzimidazoles new derivatives in good yields. The FT-IR, 19F-NMR, 1H-NMR, 13C-NMR spectra and elemental analysis confirm the structure of compounds.

  15. KLM's boric acid reclamation system (BARS). An update

    International Nuclear Information System (INIS)

    Schuelke, D.; Kniazewycz, B.G.; Markind, J.; Brossart, M.A.; Choi, R.C.

    1987-01-01

    KLM Technologies has implemented its Department of Energy Phase II Small Business Innovative Research (SBIR) demonstration program for a radioactive waste Boric Acid Reclamation System (BARS). Preliminary performance indicates enhanced treatment by the BARS technique over state of the art process methods for selective removal of silica and other impurities from borated water matrices. At optimal system recovery of 96-97 percent. BARS removes nominal levels of boric acid while achieving significant rejection for soluble silica and selective radioisotopes. This is indicative of superior performance compared to existing data governing standard boric acid process treatment in the presence of silica and other contaminants. Conventional technologies have also proven to be relatively expensive, utilizing costly chemically treated disposable resins for primary waste removal. The overall BARS program indicates substantial savings regarding off-site disposal costs based on reduced waste generation. Optimization of the BARS technology could have potential impact on conventional process technologies that are essentially non-selective in removal capacities. Within the scope of the project, a variety of contaminated process stream and mixed radwaste sources have been evaluated at Northern States Power's Prairie Island Nuclear Generating Station. The design of an advanced prototype BARS as an optimized process alternative was the result of KLM's initial Phase 1 SBIR program with the DOE in 1984 and 1985

  16. KLM's Boric Acid Reclamation System (BARS): An update

    International Nuclear Information System (INIS)

    Schuelke, D.; Kniazewycz, B.G.; Markind, J.; Brossart, M.A.; Choi, R.C.

    1987-02-01

    KLM Technologies has implemented its Department of Energy Phase II Small Business Innovative Research (SBIR) demonstration program for a radioactive waste Boric Acid Reclamation System (BARS). Preliminary performance indicates enhanced treatment by the BARS technique over state of the art process methods for selective removal of silica and other impurities from borated water matrices. At optimal system recovery of 96 to 97%, BARS removes nominal levels of boric acid while achieving significant rejection for soluble silica and selective radioisotopes. This is indicative of superior performance compared to existing data governing standard boric acid process treatment in the presence of silica and other contaminants. Conventional technologies have also proven to be relatively expensive, utilizing costly chemically treated disposable resins for primary waste removal. The overall BARS program indicates substantial savings regarding off-site disposal costs based on reduced waste generation. Optimization of the BARS technology could have potential impact on conventional process technologies that are essentially non-selective in removal capacities. 2 figs

  17. 40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN P-97-553...

  18. Characterisation of boric acid aerosol behaviour and interactions with stainless steel

    International Nuclear Information System (INIS)

    Anderson, A.B.; Beard, A.M.; Bennett, P.J.; Benson, C.G.

    1991-03-01

    Experiments have been conducted to determine the physical characteristics of boric acid aerosol. Aqueous solutions of boric acid (either 200 or 2000 ppm boron) were injected at a controlled rate onto a 304 stainless steel cone held at 1000 o C. The transport and deposition of the resulting aerosol was studied through a system including pipework and a dilution chamber. Work was also undertaken to characterise the interaction between boric acid and stainless steel. Boric acid was vaporized in steam-argon atmospheres at 300 o C and passed over 304 stainless steel coupons held at temperatures between 400 and 1000 o C. (author)

  19. Zinc-Nickel Codeposition in Sulfate Solution Combined Effect of Cadmium and Boric Acid

    Directory of Open Access Journals (Sweden)

    Y. Addi

    2011-01-01

    Full Text Available The combined effect of cadmium and boric acid on the electrodeposition of zinc-nickel from a sulfate has been investigated. The presence of cadmium ion decreases zinc in the deposit. In solution, cadmium inhibits the zinc ion deposition and suppresses it when deposition potential value is more negative than −1.2 V. Low concentration of CdSO4 reduces the anomalous nature of Zn-Ni deposit. Boric acid decreases current density and shifts potential discharge of nickel and hydrogen to more negative potential. The combination of boric acid and cadmium increases the percentage of nickel in the deposit. Boric acid and cadmium.

  20. Esterification of microcrystalline cellulose by binary mixture of pyromellitic dianhydride and boric acid

    International Nuclear Information System (INIS)

    Arslanov, Sh.S.; Petropavlovskij, G.A.

    1996-01-01

    The reaction between microcrystalline cellulose and boric acid in the medium of dimethyl-sulfoxide (DMSO) and in solid phase has been studied. By the methods of IR and 1 H NMR spectroscopy it has been shown that the triatment of cellulose with boric acid solution in DMSO, while the latter is removed under vacuum conditions and cellulose is heated up to 170 deg C, gives rise to formation of unstable esters of cellulose and boric acid. Pyromellitate-borates of cellulose are formed in the course of cellulose reaction with a mixture of boric acid and pyromellite dianhydride. 9 refs., 3 figs., 1 tab

  1. Determination of boron as boric acid by automatic potentiometric titration

    International Nuclear Information System (INIS)

    Midgley, D.

    1988-06-01

    Boron in PWR primary coolant and related waters may be determined as boric acid by titration with sodium hydroxide, using a glass electrode as a pH indicator. With a modern automatic titrator, the analysis is quick, convenient, accurate and precise. In the titration of 8 mg B (e.g. 4 ml of 2000 mg 1 -1 solution), no significant bias was observed and relative standard deviations were about 0.25%. With 0.8 g B, a bias of about 2% appears, although this could be reduced by restandardizing the titrant, but the relative standard deviation was still -1 B, depending on the stage of the fuel cycle. (author)

  2. Boric acid - trilon B (glycine, acetylurea) - water systems at 25 deg C

    International Nuclear Information System (INIS)

    Skvortsov, V.G.; Rodionov, N.S.; Molodkin, A.K.; Fedorov, Yu.A.; Tsekhanskij, R.S.

    1985-01-01

    Boric acid-trilon B (glycine, acetylurea)-water systems are studied at 25 deg C by the methods of isothermal solubility densi- and refractometry. It is ascertained that all of them are of a simple eutonic type with a small salting-out effect of organic components on boric acid

  3. The boric acid - ammonium rhodanide (nitrate, sulfate) - water system at 25 deg C

    International Nuclear Information System (INIS)

    Skvortsov, V.G.; Molodkin, A.K.; Tsekhanskij, R.S.; Sadetdinov, Sh.V.; Nikonov, F.V.

    1985-01-01

    Methods of isothermal solubility and refractometry have been used to establish that boric acid-ammonium rhodanite (nitrate, sulfate) - water systems are of a simple eutonic type. Rhodanide salts out boric acid, while nitrate and sulfate salt it in. The lyotropic effect referred to the volumetric share of both anion and cation increases in the series SCN - 3 - 4 2-

  4. Boric acid - trilon B (glycine, acetylurea) - water systems at 25 deg C

    Energy Technology Data Exchange (ETDEWEB)

    Skvortsov, V G; Rodionov, N S; Molodkin, A K; Fedorov, Yu A; Tsekhanskij, R S

    1985-07-01

    Boric acid-trilon B (glycine, acetylurea)-water systems are studied at 25 deg C by the methods of isothermal solubility densi- and refractometry. It is ascertained that all of them are of a simple eutonic type with a small salting-out effect of organic components on boric acid.

  5. Ingested boric acid effect on the venom chemistry of Solenopsis invicta Buren (Hymenoptera: Formicidae)

    Science.gov (United States)

    During a field evaluation of a boric acid bait against the red imported fire ant, Solenopsis invicta Buren, it was observed that workers of intoxicated colonies produced stings with less toxic effects compared to workers from healthy colonies. In this study, the effect of boric acid on the levels o...

  6. Impacts of impregnation with boric acid and borax on the red colour ...

    African Journals Online (AJOL)

    Impacts of impregnation with boric acid and borax on the red colour tone of some hardwoods and varnishes. H Keskin, M Atar, A Ketizmen. Abstract. This study was performed to determine the impacts of impregnation with boric acid and borax on the red colour tone of some hardwoods and varnishes. For this purpose, the ...

  7. PERIODS OF VERTEBRAL COLUMN SENSITIVITY TO BORIC ACID TREATMENT IN CD-1 MICE IN UTERO

    Science.gov (United States)

    Periods of vertebral column sensitivity to boric acid treatment in CD-1 mice in utero.Cherrington JW, Chernoff N.Department of Toxicology, North Carolina State University, Raleigh, NC 27695, USA. jana_cherrington@hotmail.comBoric acid (BA) has many uses as...

  8. Device for regulating light water nuclear reactors by changing the boric acid concentration in the cooling water circuit

    International Nuclear Information System (INIS)

    Brown, W.W.; Van der Schoot, M.R.

    1980-01-01

    Small changes in boric acid concentration can be carried out quickly by a combination of an ion exchanger with temperature-dependent capacity and an evaporator. No boric acid need be extracted from the circuit or added to it. However, if large changes of concentration are required, boric acid has to be added. The evaporator is then used to separate distilled water and concentrated boric acid when the cooling water is diluted. (DG) [de

  9. Evaluation of ultrasonic technique to characterize the concentration of boric acid in liquid medium

    International Nuclear Information System (INIS)

    Kohara, Richard Yuzo Ramida

    2015-01-01

    This dissertation is to analyze the viability of using ultrasonic technique to characterize the concentration of boric acid in liquid medium non-invasively, therefore, ultrasonic tests were performed relating different boric acid concentrations with the travel time of the ultrasonic wave, also were evaluated factors able to mask the characterization of these concentrations by ultrasonic technique. The results showed that the ultrasonic technique allows the characterization of boric acid concentrations in liquid medium in very simple terms by the ultrasonic wave travel time, requiring further studies in complex conditions. (author)

  10. Liquid Superlubricity of Polyethylene Glycol Aqueous Solution Achieved with Boric Acid Additive.

    Science.gov (United States)

    Ge, Xiangyu; Li, Jinjin; Zhang, Chenhui; Luo, Jianbin

    2018-03-27

    Boric acid is a weak acid and has been used as a lubrication additive because of its special structure. In this study, we report that boric acid could achieve a robust superlubricity (μ friction coefficient of approximately 0.004-0.006 could be achieved with boric acid under neutral conditions (pH of approximately 6.4), which is different from the acidic conditions leading to superlubricity. The influence of various factors, including boric acid concentration, sliding speed, applied load, PEG molecular weight, and the volume of lubricant on the superlubricity, were investigated. The results reveal that the PEG aqueous solution with the boric acid additive could achieve superlubricity under a wide range of conditions. The surface composition analysis shows that the synergy effect between boric acid and PEG provides sufficient H + ions to realize the running-in process. Moreover, a composite tribochemical film composed of silica and ammonia-containing compounds were formed on the ball surface, contributing to the superlubricity. The film thickness calculation shows that superlubricity was achieved in a mixed lubrication region, and therefore, the superlubricity state was dominated by both the composite tribochemical film formed via the tribochemical reaction on the contact surfaces and the hydrodynamic lubricating film between the contact surfaces. Such a liquid superlubricity achieved under neutral conditions is of importance for both scientific understanding and engineering applications.

  11. Boric acid - ammonium rhodanide (nitrate, sulfate) - water system at 25 deg C

    Energy Technology Data Exchange (ETDEWEB)

    Skvortsov, V G; Molodkin, A K; Tsekhanskij, R S; Sadetdinov, Sh V; Nikonov, F V [Chuvashskij Gosudarstvennyj Pedagogicheskij Inst., Cheboksary (USSR); Universitet Druzhby Narodov, Moscow (USSR))

    1985-03-01

    Methods of isothermal solubility and refractometry have been used to establish that boric acid-ammonium rhodanite (nitrate, sulfate) - water systems are of a simple eutonic type. Rhodanide salts out boric acid, while nitrate and sulfate salt it in. The lyotropic effect referred to the volumetric share of both anion and cation increases in the series SCN/sup -/ < NO/sub 3//sup -/ < SO/sub 4//sup 2 -/.

  12. 40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO3), zinc salt (2=3). 721.3031 Section 721.3031 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3031 Boric acid (H3BO...

  13. Experimental Study and Reactive Transport Modeling of Boric Acid Leaching of Concrete

    Directory of Open Access Journals (Sweden)

    Chiang K.-T. K.

    2013-07-01

    Full Text Available Borated water leakage through spent fuel pools (SFPs at pressurized water reactors is a concern because it could cause corrosion of reinforcement steel in the concrete structure, compromise the integrity of the structure, or cause unmonitored releases of contaminated water to the environment. Experimental data indicate that pH is a critical parameter that determines the corrosion susceptibility of rebar in borated water and the degree of concrete degradation by boric acid leaching. In this study, reactive transport modeling of concrete leaching by borated water was performed to provide information on the solution pH in the concrete crack or matrix and the degree of concrete degradation at different locations of an SFP concrete structure exposed to borated water. Simulations up to 100 years were performed using different boric acid concentrations, crack apertures, and solution flow rates. Concrete cylinders were immersed in boric acid solutions for several months and the mineralogical changes and boric acid penetration in the concrete cylinder were evaluated as a function of time. The depths of concrete leaching by boric acid solution derived from the reactive transport simulations were compared with the measured boric acid penetration depth.

  14. Removal of Aqueous Boron by Using Complexation of Boric Acid with Polyols: A Raman Spectroscopic Study

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Ki Heon; Jeong, Hui Cheol; An, Hye Young; Lim, Jun-Heok; Lee, Jea-Keun; Won, Yong Sun [Pukyong National University, Busan (Korea, Republic of)

    2015-12-15

    Boron is difficult to be removed from seawater by simple RO (reverse osmosis) membrane process, because the size of boric acid (B(OH){sub 3}), the major form of aqueous boron, is as small as the nominal pore size of RO membrane. Thus, the complexation of boric acid with polyols was suggested as an alternative way to increase the size of aqueous boron compounds and the complexation behavior was investigated with Raman spectroscopy. As a reference, the Raman peak for symmetric B-O stretching vibrational mode both in boric acid and borate ion (B(OH){sub 4}{sup -}) was selected. A Raman peak shift (877 cm{sup -1} →730 cm{sup -1}) was observed to confirm that boric acid in water is converted to borate ion as the pH increases, which is also correctly predicted by frequency calculation. Meanwhile, the Raman peak of borate ion (730 cm{sup -1}) did not appear as the pH increased when polyols were applied into aqueous solution of boric acid, suggesting that the boric acid forms complexing compounds by combining with polyols.

  15. High production of D-tagatose by the addition of boric acid.

    Science.gov (United States)

    Lim, Byung-Chul; Kim, Hye-Jung; Oh, Deok-Kun

    2007-01-01

    An L-arabinose isomerase mutant enzyme from Geobacillus thermodenitrificans was used to catalyze the isomerization of D-galactose to D-tagatose with boric acid. Maximum production of D-tagatose occurred at pH 8.5-9.0, 60 degrees C, and 0.4 molar ratio of boric acid to D-galactose, and the production increased with increasing enzyme concentration. Under the optimum conditions, the enzyme (10.8 units/mL) converted 300 g/L D-galactose to 230 g/L D-tagatose for 20 h with a yield of 77% (w/w); the production and conversion yield with boric acid were 1.5-fold and 24% higher than without boric acid, respectively. In 24 h, the enzyme produced 370 g/L D-tagatose from 500 g/L D-galactose with boric acid, corresponding to a conversion yield of 74% (w/w) and a production rate of 15.4 g/L.h. The production and yield of D-tagatose obtained in this study are unprecedented.

  16. Preliminary Evaluation Of DWPF Impacts Of Boric Acid Use In Cesium Strip FOR SWPF And MCU

    International Nuclear Information System (INIS)

    Stone, M.

    2010-01-01

    A new solvent system is being evaluated for use in the Modular Caustic-Side Solvent Extraction Unit (MCU) and in the Salt Waste Processing Facility (SWPF). The new system includes the option to replace the current dilute nitric acid strip solution with boric acid. To support this effort, the impact of using 0.01M, 0.1M, 0.25M and 0.5M boric acid in place of 0.001M nitric acid was evaluated for impacts on the DWPF facility. The evaluation only covered the impacts of boric acid in the strip effluent and does not address the other changes in solvents (i.e., the new extractant, called MaxCalix, or the new suppressor, guanidine). Boric acid additions may lead to increased hydrogen generation during the SRAT and SME cycles as well as change the rheological properties of the feed. The boron in the strip effluent will impact glass composition and could require each SME batch to be trimmed with boric acid to account for any changes in the boron from strip effluent additions. Addition of boron with the strip effluent will require changes in the frit composition and could lead to changes in melt behavior. The severity of the impacts from the boric acid additions is dependent on the amount of boric acid added by the strip effluent. The use of 0.1M or higher concentrations of boric acid in the strip effluent was found to significantly impact DWPF operations while the impact of 0.01M boric acid is expected to be relatively minor. Experimental testing is required to resolve the issues identified during the preliminary evaluation. The issues to be addressed by the testing are: (1) Impact on SRAT acid addition and hydrogen generation; (2) Impact on melter feed rheology; (3) Impact on glass composition control; (4) Impact on frit production; and (5) Impact on melter offgas. A new solvent system is being evaluated for use in the Modular Caustic-Side Solvent Extraction Unit (MCU) and in the Salt Waste Processing Facility (SWPF). The new system includes the option to replace the

  17. Chloride stress corrosion cracking of Alloy 600 in boric acid solutions

    International Nuclear Information System (INIS)

    Berge, Ph.; Noel, D.; Gras, J.M.; Prieux, B.

    1997-10-01

    The high nickel austenitic alloys are generally considered to have good resistance to chloride stress corrosion cracking. In the standard boiling magnesium chloride solution tests, alloys with more than 40% nickel are immune. Nevertheless, more recent data show that cracking can occur in both Alloys 600 and 690 if the solution is acidified. In other low pH media, such as boric acid solution at 100 deg C, transgranular and intergranular cracking are observed in Alloy 600 in the presence of minor concentrations of sodium chloride (2g/I). In concentrated boric acid at higher temperatures (250 and 290 deg C), intergranular cracking also occurs, either when the chloride concentration is high, or at low chloride contents and high oxygen levels. The role of pH and a possible specific action of boric acid are discussed, together with the influence of electrochemical potential. (author)

  18. CEC mechanism in electrochemical oxidation of nitrocatechol-boric acid complexes

    International Nuclear Information System (INIS)

    Rafiee, Mohammad; Nematollahi, Davood; Salehzadeh, Hamid

    2011-01-01

    Graphical abstract: Display Omitted Highlights: → Nitrochetechol and its anionic form undergo complex reaction with boric acid. → The electron transfer of complex is coupled with both proceeding and following chemical reactions. → Electrochemical behavior of complex is resolved by diagnostic criteria and digital simulation. - Abstract: The electrochemical behavior of nitrocatechols-boric acid complexes in aqueous solution has been studied using cyclic voltammetry. The results indicate that nitrocatechol-boric acid complex derivatives are involved in the CEC mechanism. In this work, the impact of empirical parameters on the shape of the voltammograms is examined based on a CEC mechanism. In addition, homogeneous rate constants of both the preceding and the following reactions were estimated by comparing the experimental cyclic voltammograms with the digitally simulated results. The calculated dissociation constants for the complexes (K d ) and for ring cleavage of nitroquinone (k f2 ) were found to vary in the following order: 4-nitrocatechol > 3-methylnitrocatechol > 3-metoxynitrocatechol.

  19. Synergy of boric acid and added salts in the catalytic dehydration of hexoses to 5-hydroxymethylfurfural in water

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Mielby, Jerrik Jørgen; Riisager, Anders

    2011-01-01

    Boric acid and salts showed a synergistic effect on the dehydration of concentrated aqueous sugar solutions to yield 5-hydroxymethylfurfural.......Boric acid and salts showed a synergistic effect on the dehydration of concentrated aqueous sugar solutions to yield 5-hydroxymethylfurfural....

  20. Boric acid as a mild and efficient catalyst for one-pot synthesis of 1

    Indian Academy of Sciences (India)

    Abstract. An efficient green chemistry method has been developed for the synthesis of 1-amidoalkyl-2-naphthol derivatives via a one-pot three-component condensation of 2-naphthol, aldehydes and amide in the presence of boric acid as a mild catalyst.

  1. Mitochondrial dysfunction is involved in the toxic activity of boric acid against Saprolegnia.

    Directory of Open Access Journals (Sweden)

    Shimaa E Ali

    Full Text Available There has been a significant increase in the incidence of Saprolegnia infections over the past decades, especially after the banning of malachite green. Very often these infections are associated with high economic losses in salmonid farms and hatcheries. The use of boric acid to control the disease has been investigated recently both under in vitro and in vivo conditions, however its possible mode of action against fish pathogenic Saprolegnia is not known. In this study, we have explored the transformation in Saprolegnia spores/hyphae after exposure to boric acid (1 g/L over a period 4-24 h post treatment. Using transmission electron microscopy (TEM, early changes in Saprolegnia spores were detected. Mitochondrial degeneration was the most obvious sign observed following 4 h treatment in about 20% of randomly selected spores. We also investigated the effect of the treatment on nuclear division, mitochondrial activity and function using confocal laser scanning microscopy (CLSM. Fluorescence microscopy was also used to test the effect of treatment on mitochondrial membrane potential and formation of reactive oxygen species. Additionally, the viability and proliferation of treated spores that correlated to mitochondrial enzymatic activity were tested using an MTS assay. All obtained data pointed towards changes in the mitochondrial structure, membrane potential and enzymatic activity following treatment. We have found that boric acid has no effect on the integrity of membranes of Saprolegnia spores at concentrations tested. It is therefore likely that mitochondrial dysfunction is involved in the toxic activity of boric acid against Saprolegnia spp.

  2. Galvanic corrosion between carbon steel 1018 and Alloy 600 in crevice with boric acid solution

    International Nuclear Information System (INIS)

    Kim, Dong Jin; Kim, Hong Pyo; Kim, Joung Soo; Machonald, Digby D.

    2005-01-01

    This work dealt with the evaluation of galvanic corrosion rate in a corrosion cell having annular gap of 0.5 mm between carbon steel 1018 and alloy 600 as a function of temperature and boron concentration. Temperature and boron concentration were ranged from 110 to 300 .deg. C and 2000∼10000 ppm, respectively. After the operating temperature of the corrosion cell where the electrolyte was injected was attained at setting temperature, galvanic coupling was made and at the same time galvanic current was measured. The galvanic corrosion rate decreased with time, which was described by corrosion product such as protective film as well as boric acid deposit formed on the carbon steel with time. From the galvanic current obtained as a function of temperature and boron concentration, it was found that the galvanic corrosion rate decreased with temperature while the corrosion rate increased with boron concentration. The experimental results obtained from galvanic corrosion measurement were explained by adhesive property of corrosion product such as protective film, boric acid deposit formed on the carbon steel wall and dehydration of boric acid to be slightly soluble boric acid phase. Moreover the galvanic corrosion rate calculated using initial galvanic coupling current instead of steady state coupling current was remarked, which could give us relatively closer galvanic corrosion rate to real pressurized water reactor

  3. Enriched boric acid as an optimized neutron absorber in the EPR primary coolant

    International Nuclear Information System (INIS)

    Cosse, Christelle; Jolivel, Fabienne; Berger, Martial

    2012-09-01

    This paper focuses on one of the most important EPR PWR reactor design optimizations, through primary coolant conditioning by enriched boric acid (EBA). On PWRs throughout the world, boric acid has already been implemented in primary coolant and associated auxiliary systems for criticality control, due to its high Boron 10 neutron absorption cross section. Boric acid also allows primary coolant pH 300C control in combination with lithium hydroxide in many PWRs. The boric acid employed in the majority of existing PWRs is the 'natural' one, with a typical isotopic atomic abundance in Boron 10 about 19.8 at.%. However, EPR requirements for neutron management are more important, due to its fully optimized design compared to older PWRs. From the boron point of view, it means that criticality could be controlled either by increased 'natural' Boron concentrations or by using EBA. Comparatively to 'natural' boric acid, EBA allows for: - the use of smaller storage volumes for an identical total Boron concentration, or lower total Boron concentration if the tank volumes are kept identical. The latter also reduces the risks of boric acid crystallization, in spite of increased neutron-absorbing properties - the application of an evolutionary chemistry operating regime called Advanced pH Control, making it possible to maintain a constant pH 300C value at 7.2 in the primary coolant at nominal conditions throughout entire cycles. This optimized stability of pH 300C will contribute to reduce the consequences of contamination of the reactor coolant system by corrosion products, and consequently, all related issues - the reduction of borated liquid wastes, thanks to maximal recycling resulting from EPR design. The increased design costs associated with EBA are consequently compensated by a reduced total consumption of this chemical. Therefore, the basic design choice for the EPR is the use of EBA. For the Flamanville 3 EPR, according to the above

  4. Boric acid reduces axonal and myelin damage in experimental sciatic nerve injury

    Directory of Open Access Journals (Sweden)

    Zahir Kizilay

    2016-01-01

    Full Text Available The aim of this study was to investigate the effects of boric acid in experimental acute sciatic nerve injury. Twenty-eight adult male rats were randomly divided into four equal groups (n = 7: control (C, boric acid (BA, sciatic nerve injury (I , and sciatic nerve injury + boric acid treatment (BAI. Sciatic nerve injury was generated using a Yasargil aneurysm clip in the groups I and BAI. Boric acid was given four times at 100 mg/kg to rats in the groups BA and BAI after injury (by gavage at 0, 24, 48 and 72 hours but no injury was made in the group BA. In vivo electrophysiological tests were performed at the end of the day 4 and sciatic nerve tissue samples were taken for histopathological examination. The amplitude of compound action potential, the nerve conduction velocity and the number of axons were significantly lower and the myelin structure was found to be broken in group I compared with those in groups C and BA. However, the amplitude of the compound action potential, the nerve conduction velocity and the number of axons were significantly greater in group BAI than in group I. Moreover, myelin injury was significantly milder and the intensity of nuclear factor kappa B immunostaining was significantly weaker in group BAI than in group I. The results of this study show that administration of boric acid at 100 mg/kg after sciatic nerve injury in rats markedly reduces myelin and axonal injury and improves the electrophysiological function of injured sciatic nerve possibly through alleviating oxidative stress reactions.

  5. Experimental and modeling study of Portland cement paste degradation in boric acid

    International Nuclear Information System (INIS)

    Benakli, A.; Chomat, L.; Le Bescop, P.; Wall, J.

    2015-01-01

    In the framework of Spent Fuel Pools (SFP) lifetime studies, an investigation of the Portland cement degradation in boric acid has been requested by the Electric Power Research Institute. The main goal of this study is to identify the physico-chemical degradation mechanisms involved in boric acid media. Both experimental and modeling approaches are considered. Concerning degradation experiments, sample of cement paste are immersed during three and nine months in a boric acid solution at 2400 ppm that is periodically renewed. Boric acid concentration has been chosen to be representative of SFP solution. Results will be confronted with reactive transport numerical calculations performed by the reactive transport code HYTEC associated with a dedicated extended database called Thermoddem. The analysis of degradation solution revealed a main ions release mechanism driven by diffusion especially for calcium, nitrate, sodium and sulfate. Leaching behavior of magnesium seems to be more complex. Decalcification is the major degradation process involved, even if a non-negligible contribution of further cations (Mg 2+ , Na + ) and anions (SO 4 2- ) has been noticed. Analysis of degradation soution also revealed that kinetic of Portland cement paste degradation in boric acid is higher than in pure water, regarding the degraded depths measured and calcium leaching rate. This observation has been confirmed by solid characterization. Microstructure analysis of degraded Portland cement paste showed a global porosity increase in the degraded zone that might be mainly attributed to Portlandite dissolution. An Ettringite reprecipitation in the degraded zone has been suspected but could also be Ettringite-like phases containing boron. The analysis techniques used did not allow us to differentiate it, and no others specific mineral phases containing boron has been identified. Profile pattern by XRD analysis allowed us to identify four zones composing the degraded Portland cement paste

  6. Effect of boric acid on intergranular corrosion and on hideout return efficiency of sodium in the tube support plate crevices

    International Nuclear Information System (INIS)

    Paine, J.P.N.; Shoemaker, C.E.; Campan, J.L.; Brunet, J.P.; Schindler, P.; Stutzmann, A.

    1995-01-01

    Sodium hydroxide is one of the main causes of intergranular attack/stress corrosion cracking (IGA/SCC) of alloy 600 steam generator (S.G.) tubes. Boric acid appears to be one of the possible remedies for intergranular corrosion process inhibition. In order to obtain data on boric acid injection efficiency, an experimental program was performed on previously corroded tubes. To prevent premature tube wall cracking, samples were sleeved on alloy 690 tubes. The objective of the tests was to evaluate, on a statistically valid number of samples, the effectiveness of boric acid and tube sleeving as possible remedies for IGA/SCC extension. Another independent experimental program was initiated to determine the hideout return efficiency in the tube support plate (TSP) and tubesheet (TS) crevices after a significant duration (≤ 180 hours) of sodium hideout. The main objective of the first tests being a statistical evaluation of the efficiency of boric acid treatment, was not achieved. The tests did demonstrate that sleeving effectively reduces IGA/SCC growth. In an additional program, cracks were obtained on highly susceptible tubes when specimens were not sleeved. The companion tests performed in the same conditions but with an addition of boric acid did not show any IGA or cracks. These results seem to demonstrate the possible effect of boric acid in preventing the corrosion process. Results of the second tests did not demonstrate any difference in the amount of sodium piled up in the crevices before and after boric acid injection. They however showed an increase of the hideout return efficiency at the tube support plate level from 78 % without boric acid to 95 % when boric acid is present in the feed water

  7. Electrodialysis recovery of boric acid and potassium hydroxide from eluates of SWC facilities at NPP with VVER

    International Nuclear Information System (INIS)

    Dudnik, S.N.; Virich, P.M.; Kramskikh, E.Y.; Masanov, O.L.; Turovsky, I.P.

    1993-01-01

    To extract boric acid and potassium hydroxide from regenerates of SWC-2-46 facilities, an electrodialysis-sorption process has been devised consisting of the following operations: separation of boron-alkaline regenerate solution into desorbate and wash water; filling of desalination and concentration chambers, respectively, with desorbate and was water of electrodialysis equipment; production of boric acid and potassium hydroxide from desorbate by electrodialysis; removal of chloride-ion from boric acid solution on ion-exchange filter AB-17-18. The flow-sheet was tested and boron containing alkaline regeneration solutions were recovered from Novovoronezh NPP

  8. Enhanced activity of Anticarsia gemmatalis Hüb. (Lepidoptera: Noctuidae) nuclear polyhedrosis virus by boric acid in the laboratory

    OpenAIRE

    Morales, Lauro; Moscardi, Flávio; Sosa-Gómez, Daniel R.; Paro, Fábio E.; Soldorio, Ivanilda L.

    1997-01-01

    Boric acid concentrations (0.02,0.03,0.045,0.067 and 0.101 g/100 ml of diet) were evaluated in combination with the Anticarsia gemmatalis Hüb. nuclear polyhedrosis virus (AgNPV) for enhanced virali activity against the insect. Seven days after inoculation, the median lethal concentration (LC50) was 1.52 x 10(5) for the AgNPV alone and 7.95 x 10² for the NPV mixed with 0.045g of boric acid/100 ml of diet. At subsequent evaluation dates (9,11 and 14 days after inoculation) LC50's for NPV+boric ...

  9. Effect of complexing reagents on the ionization constant of boric acid and its relation to isotopic exchange separation factor

    International Nuclear Information System (INIS)

    Sharma, B.K.; Subramanian, R.; Mathur, P.K.

    1991-01-01

    The effect of change in concentration of complexing reagents having two or more hydroxyl groups, viz., ethylene glycol, propylene glycol, dextrose and mannitol on the ionization constant of boric acid has been studied by pH-metric titration method. The effect of increase in ionization constant of boric acid on isotopic exchange separation factor for the separation of isotopes of boron by ion exchange chromatography has been studied by the batch method. (author). 9 refs

  10. Estimation of influence of a solution of a boric acid and temperatures on a isolation material from basalt fibers

    International Nuclear Information System (INIS)

    Pyshnova, V.V.; Skobelkina, T.N.; Yurchenko, V.G.; Knot'ko, A.V.; Putlyaev, V.I.

    2006-01-01

    Paper presents the results of investigation into long-term simultaneous effect of a medium (boric acid solution) and temperature on a thermal-insulating basalt fiber material. The basalt fiber clothes used at the NPP were tested. When evaluating simultaneous effect of boric acid solution and temperature one kept watch on density, compressibility, elasticity and diameter of fiber. According to the results of 30 day tests, the basic technical parameters of the thermal-insulating material have changed insignificantly [ru

  11. The characterisation of molecular boric acid by mass spectrometry and matrix isolation-infrared spectroscopy

    International Nuclear Information System (INIS)

    Ogden, J.S.; Young, N.A.; Bowsher, B.R.

    1987-10-01

    Boric acid (H 3 BO 3 ) is used as a soluble neutron absorber in the coolant of pressurised water reactors and will be an important species in defining the fission product chemistry of severe reactor accidents. Mass spectrometry and matrix isolation-infrared spectroscopy have been used to characterise boric acid in the vapour phase and hence assess the implications of any chemical interactions. Crystalline orthoboric acid vaporises to yield molecular H 3 BO 3 when heated in vacuum to approximately 40 0 C. The infrared spectrum of the vapour species isolated in low-temperature nitrogen matrices shows characteristic absorptions at 3668.5 (E'), 1426.2 (E'), 1009.9 (E'), 675.0 (A''), 513.8 (A'') and 448.9 (E') cm -1 , consistent with C 3h symmetry. These spectral assignments are supported by extensive isotope labelling, and by a partial normal co-ordinate analysis. These data will be used to quantify specific thermodynamic functions and hence assist in determining the magnitude of reactions such as boric acid with caesium iodide. (author)

  12. Genotoxic effects of boric acid and borax in zebrafish, Danio rerio using alkaline comet assay.

    Science.gov (United States)

    Gülsoy, Nagihan; Yavas, Cüneyd; Mutlu, Özal

    2015-01-01

    The present study is conducted to determine the potential mechanisms of Boron compounds, boric acid (BA) and borax (BX), on genotoxicity of zebrafish Danio rerio for 24, 48, 72 and 96-hours acute exposure (level:1, 4, 16, 64 mg/l BA and BX) in semi-static bioassay experiment. For that purpose, peripheral erythrocytes were drawn from caudal vein and Comet assay was applied to assess genotoxicity. Acute (96 hours) exposure and high concentrations of boric acid and borax increases % tail DNA and Olive tail moment. Genotoxicity was found for BA as concentration-dependent and BX as concentration and time dependent manner. In general, significant effects (P borax-induced genotoxicity in fish.

  13. EFFECTS.OF BORIC ACID ON THE CURE OF BORON-FILLED Y-3602 SILICONE GUM

    Energy Technology Data Exchange (ETDEWEB)

    Leichliter, G E

    1974-10-01

    The first two phases of a program designed to determine the effects of boric acid on the cure of Y-3602 silicone gum were conducted to evaluate extraction solvents and extraction time. The standard production formulation of B10-filled Y-3602 silicone gum was used in these evaluations. Results showed that the best solvent for reproducibility and high amine content was chloroform. The second phase indicated that extraction was essentially complete at the end of 4 hours.

  14. 59Ni and 63Ni separation from boric acid concentrates produced at NPP

    International Nuclear Information System (INIS)

    Fisera, O.

    2010-01-01

    Procedure for direct separation of radionickel from boric acid concentrate was developed. Quantitative separation from 100 mL of real concentrate on the column filled with 3 mL of PAN-DMG composite material was achieved. PAN-DMG material (dimethylglyoxime in porous beads of polyacrylonitrile) was compared with Ni Resin and DMG-PAN material exhibited higher sorption capacity for nickel than Ni Resin. (author)

  15. Effect of boric acid on intergranular corrosion in tube support plate crevices

    International Nuclear Information System (INIS)

    Brunet, J.P.; Campan, J.L.

    1993-10-01

    Intergranular attack on steam generator tubing is one important phenomenon involved in availability of Pressurized Water Reactors. Boric acid appears to be a possible candidate for inhibiting the corrosion process. The program performed in Cadarache was supposed to give statistical informations on the boric acid effect. It was based on a large number of samples initially attacked during a program performed by BABCOCK ampersand WILCOX. These samples were sleeved onto Alloy 690 tubes, in order to prevent premature cracking. Unfortunately it was not possible to find chemical conditions able to produce significant additional corrosion; we postulated mainly due to a drastic reduction of the thermal flux resulting from the increase of the tube wall thickness under the tube support plates (TSP). The tests demonstrate that such sleeve could be a possible remedy of the corrosion when introduced under the TSP. The tests show indications of a possible beneficial effect of the boric acid, a large variability of the heats sensitivity to the IGA and a predominant effect of Na 2 CO 3 on IGA production

  16. Breaking Bad Delirium: Methamphetamine and Boric Acid Toxicity with Hallucinations and Pseudosepsis.

    Science.gov (United States)

    Johnson, Kayla; Stollings, Joanna L; Ely, E Wesley

    2017-02-01

    A 30-year-old patient presented with hallucinations and profound shock. He was initially misdiagnosed as having severe sepsis; once ingestions were considered, he was diagnosed as potentially having arsenic toxicity. The clinical story reveals many instructional lessons that could aid in the evaluation and management of future patients. This man presented with large amounts of blue crystals around his nose and lips from inhaling and eating boric acid (an ant poison) so he could, as he put it, kill the ants "pouring into my mouth and nose and up into my brain." His profound pseudosepsis and sustained delirium were induced by co-ingestion of methamphetamine and a large quantity of boric acid. Delirium is a form of acute brain dysfunction that often is multifactorial in critical illness and, when seen in septic shock, is associated with prolonged mechanical ventilation, increased length of hospital stay, medical costs, higher mortality, and long-term cognitive impairment resembling dementia. Pseudosepsis is a noninfectious condition most commonly seen with ingestions such as salicylate (aspirin) toxicity. This report emphasizes the need to recognize agents that contain boric acid as an etiology of unexplained delirium and profound shock.

  17. Influence of temperature, hydrogen and boric acid concentration on IGSCC susceptibility of unsensitized 316 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Arioka, Koji [Inst. of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2002-09-01

    IGSCC susceptibility of unsensitized 316SS under PWR primary water was studied as a function of solution temperature, dissolved hydrogen, and boric acid concentration by SSRT test using specimens with cold deformed hump. IGSCC growth rate was dependent on temperature and the obtained activation energy was 21.6K cal/mol. Regarding the influence of dissolved hydrogen, there was a simple monotonic increase in crack growth rate with the increasing hydrogen concentration within the PWR primary water chemistry specifications. Also, there was a remarkable difference in IGSCC susceptibility with regard to the effect to boric acid concentration. Within the tested concentration, the IGSCC susceptibility under high concentrated boric acid solution (2300ppm B) was inhibited in comparison with that under 500ppm B. These temperature and dissolved hydrogen dependencies of IGSCC susceptibility were similar to the literature on published data on irradiated 316SS. Although further study is required to clarify the mechanism, however the similarity of the dependencies suggests that the rate-limited IGSCC process of un-irradiated 316SS is related to that of IASCC. (author)

  18. Application of Lime Additive on Cementation of Concentrated Low Activities Liquid Radwaste Containing Boric Acid

    International Nuclear Information System (INIS)

    Bahdir-Johan

    2000-01-01

    The effect of lime additive on the waste form containing boric acid and the activity 1 μCi/ml have been studied. The studying parameter was the optimum lime additive in concentrate. The sample was made by cement slurry containing boric acid. The cement slurry composition are water/cement ratio (W/C) was 0.35, sand/cement ratio (S/C) was 0.75 and boric (B) was 15000 ppm. On this condition into cement slurry was added the lime additive (K/C) 0.05 -0.8 by weigh. The quality test included density, compressive strength and leaching rate. The density was determination by weighing and measuring sample volume, compressive strength determination using Paul Weber apparatus and leaching rate tested using aquadest. The result of this research are the lime/cement ratio (K/C) 0.30; the density (ρ) 2.449 ± 0.008 g.cm -3 , the compressive strength (Γ) 44.005 ± 0.012 N.mm -2 and the leaching rate (Rn) 7.20x10 -4 -0.90x10 -4 g.cm -2 day -1 . According to this research the quality of the waste form has been complied the IAEA quality standard. (author)

  19. Inhibition studies of soybean (Glycine max) urease with heavy metals, sodium salts of mineral acids, boric acid, and boronic acids.

    Science.gov (United States)

    Kumar, Sandeep; Kayastha, Arvind M

    2010-10-01

    Various inhibitors were tested for their inhibitory effects on soybean urease. The K(i) values for boric acid, 4-bromophenylboronic acid, butylboronic acid, and phenylboronic acid were 0.20 +/- 0.05 mM, 0.22 +/- 0.04 mM, 1.50 +/- 0.10 mM, and 2.00 +/- 0.11 mM, respectively. The inhibition was competitive type with boric acid and boronic acids. Heavy metal ions including Ag(+), Hg(2+), and Cu(2+) showed strong inhibition on soybean urease, with the silver ion being a potent inhibitor (IC(50) = 2.3 x 10(-8) mM). Time-dependent inhibition studies exhibited biphasic kinetics with all heavy metal ions. Furthermore, inhibition studies with sodium salts of mineral acids (NaF, NaCl, NaNO(3), and Na(2)SO(4)) showed that only F(-) inhibited soybean urease significantly (IC(50) = 2.9 mM). Competitive type of inhibition was observed for this anion with a K(i) value of 1.30 mM.

  20. Further investigation on boric acid catalytic graphitization of polyacrylonitrile carbon fibers: Mechanism and mechanical properties

    International Nuclear Information System (INIS)

    Wen, Ya; Lu, Yonggen; Xiao, Hao; Qin, Xianying

    2012-01-01

    Highlights: ► The modulus of carbon fiber was improved by boric acid at the temperature range of 1500–2900 °C. ► 2300 °C is a key temperature degree from which the boron began to benefit fiber strength. ► The fiber strength was affected by the boron reaction and related to the boron states. -- Abstract: Catalytic graphitization of polyacrylonitrile based carbon fibers by boric acid doping was studied and the dependence of fiber tensile strength on the boron content and temperature was discussed. It was found that there existed a key temperature point for the boron to take effect. When the fibers were modified with 7.0 wt.% boric acid solution, with increasing temperature, the tensile strength was lower than that of the unmodified ones below 2300 °C, but a reverse thing happened above 2300 °C. Moreover, when being heated at 2500 °C, the modified fibers showed an increasing tensile modulus and strength with increasing boron content till maximums of 404 GPa and 2.46 GPa, 26% and 16% higher than those of unmodified ones. The mechanical properties of the fibers were affected by the interaction of carbon and boron, and also related with boron states. The decomposition of boron acid and its interaction with carbon brought defects on fiber surface, degrading the mechanical properties below 1300 °C. With further heat treatment, the boron diffused into the fibers and divided into two states: substitutional and interstitial. At a temperature over 2300 °C with an appreciate boron content, the substitutional would be formed predominantly, which removed the structural defects and relaxed the distortions, so as to benefit the mechanical properties.

  1. Effect of nano-silver and boric acid on extending the vase life of cut rose (Rosa hybrida L.).

    Science.gov (United States)

    Hashemabadi, Davood; Liavali, Mahbanoo Hoseinzadeh; Kaviani, Behzad; Mousavi, Meysam; Keyghobadi, Saghi; Zahiri, Samaneh

    2014-09-01

    Silver nano-particles (2-5 nm diam.), as antimicrobial agent and boric acid, as ethylene production inhibitor are used for enhancing the quality and vase life of cut flowers. In the present study the effects of a preservative solution containing nano-silver and boric acid on some traits of cut rose (Rosa hybrida L. cv. Yellow Island) including vase life, ethylene production, dry weight percentage, chlorophyll content, flower opening index, beta-carotene of petals and the number of basal stem end bacteria were investigated. The results showed that the effect of nano-silver and boric acid as either solitary or in combination with each other were significant (p rose treated with 100 mg l(-1) boric acid along with 5 mg l(-1) nano-silver. The lowest number of bacteria in the end of stem was calculated in cut flowers treated with the highest concentrations of boric acid (300 mg l(-1)) and nano-silver (20 mg l(-1)).

  2. Effect of Silica Sol on Boric-sulfuric Acid Anodic Oxidation of LY12CZ Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    LIU Hui-cong

    2016-07-01

    Full Text Available Aluminum alloy anodizing coatings were prepared for LY12CZ in the boric-sulfuric acid solution (45g/L sulfuric acid,8g/L boric acid with the addition of 10%,20%,30% (volume fractionsilica sol,with the gradient voltage of 15V. The current and voltage transients of the anodizing process were collected by data collection instrument. The surface morphologies,microstructure and chemical composition of the anodic coatings were characterized by scanning electron microscopy (SEM. The corrosion resistance was examined by neutral salt spray,electrochemical impedance spectroscopy (EIS test and titrating test. The results show that the different concentration of silica sol addition can influence the forming and dissolution of anodizing coatings,improve the compactness smoothness and corrosion resistance during the anodizing process in the boric-sulfuric acid solution.

  3. Determination of uranium in boric acid samples at Paks Nuclear Power Plant by ICP-MS method

    International Nuclear Information System (INIS)

    Komlosi, E.Zs.; Menyhart, A.; Varju, I.

    2005-01-01

    Measurement of uranium became necessary in 2003, after the incident of unit 2 in April, when the fission products, uranium and transuranium isotopes got into the cooling water. The measurement of uranium with ICP-MS method was initiated in January 2004. Apparatus type Agilent 7500a was used. Uranium concentration and uranium isotope ratio were measured in samples with different - but known - boric acid concentration. Internal standard was used for the elimination of the matrix effect. The samples have high boric acid concentration (in few samples over 20 g/litres). Two methods were used for the reduction of the boric acid concentration: dilution and evaporation with ethyl alcohol. Both methods were found successful and exact. The limit of detection is 0.1 ng/litres for the Uranium-238. (N.T.)

  4. Is Boric Acid Toxic to Reproduction in Humans? Assessment of the Animal Reproductive Toxicity Data and Epidemiological Study Results.

    Science.gov (United States)

    Duydu, Yalçın; Başaran, Nurşen; Ustündağ, Aylin; Aydın, Sevtap; Undeğer, Ulkü; Ataman, Osman Yavuz; Aydos, Kaan; Düker, Yalçın; Ickstadt, Katja; Waltrup, Brita Schulze; Golka, Klaus; Bolt, Hermann Maximilian

    2016-01-01

    Boric acid and sodium borates are classified as toxic to reproduction in the CLP Regulation under "Category 1B" with the hazard statement of "H360FD". This classification is based on the reprotoxic effects of boric acid and sodium borates in animal experiments at high doses. However, boron mediated reprotoxic effects have not been proven in epidemiological studies so far. The epidemiological study performed in Bandırma boric acid production plant is the most comprehensive published study in this field with 204 voluntarily participated male workers. Sperm quality parameters (sperm morphology, concentration and motility parameters), FSH, LH and testosterone levels were determined in all participated employees as the reproductive toxicity biomarkers of males. However, boron mediated unfavorable effects on reproduction in male workers have not been determined even in the workers under very high daily boron exposure (0.21 mg B/kg-bw/day) conditions. The NOAEL for rat reproductive toxicity is equivalent to a blood boron level of 2020 ng/g. This level is higher than the mean blood boron concentration (223.89 ± 69.49 ng/g) of the high exposure group workers in Bandırma boric acid production plant (Turkey) by a factor of 9. Accordingly, classifying boric acid and sodium borates under "Category 1B" as "presumed reproductive human toxicant in the CLP regulation seems scientifically not reasonable. The results of the epidemiological studies (including the study performed in China) support for a down-classification of boric acid from the category 1B, H360FD to category 2, H361d, (suspected of damaging the unborn child).

  5. Determination of Optimum Duration and Concentration of Stevia (Stevia rebaudiana Bert.) Seed Priming with Boric Acid (H3BO3)

    OpenAIRE

    SHAHVERDI, Mehdi Aghighi; OMIDI, Heshmat; TABATABAEI, Seyed Jalal

    2017-01-01

    In order to determine optimal duration and concentration of Stevia seed priming with boric acid for improving germination, an experimental factorial completely randomized design with three replications was conducted in the laboratory of Seed Science and Technology, Shahed University of Tehran in 2015. The first factor was different concentrations of boric acid (0, 0.5, 1.0, 1.5 and 2.0 percent) and the second factor was priming duration (0, 8, 16, 24 and 32 hours). Effects of concentration an...

  6. Design of Test Facility to Evaluate Boric Acid Precipitation Following a LOCA

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Jeong-Kwan; Song, Yong-Jae [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    The U.S.NRC has identified a concern that debris associated with generic safety issue (GSI) - 191 may affect the potential precipitation of boric acid due to one or more of the following phenomena: - Reducing mass transport (i.e. mixing) between the core and the lower plenum (should debris accumulate at the core inlet) - Reduced lower plenum volume (should debris settle in the lower plenum), and, - Increased potential for boric acid precipitation (BAP) in the core (should debris accumulate in suspension in the core) To address these BAP issues, KHNP is planning to conduct validation tests by constructing a BAP test facility. This paper describes the design of test facility to evaluate BAP following a LOCA. The design of BAP test facility has been developed by KHNP. To design the test facility, test requirements and success criteria were established, and scaling analysis of power-to-volume method, Ishii-Kataoka method, and hierarchical two-tiered method were investigated. The test section is composed of two fuel assemblies with half of full of prototypic FA height. All the fuel rods are heated by the electric power supplier. The BAP tests in the presence of debris, buffering agents, and boron will be performed following the test matrix.

  7. Study of structural, surface and hydrogen storage properties of boric acid mediated metal (sodium)-organic frameworks

    Science.gov (United States)

    Ozer, Demet; Köse, Dursun A.; Sahin, Onur; Oztas, Nursen A.

    2018-04-01

    Three boric acid mediated metal organic frameworks were synthesized by solution method with using succinic acid, fumaric acid and acetylene dicarboxylic acid as a ligand source and sodium as a metal source. The complexes were characterized by FT-IR, powder XRD, elemental analyses and single crystal measurements. The complexes with the formula, C4H18B2Na2O14, C4H16B2Na2O14 and C4H14B2Na2O14 were successfully obtained. BET surface area of complexes were calculated and found as 13.474 m2/g for catena-(tetrakis(μ2-hydroxo)-(μ2-trihydrogen borate)-(μ2-succinato)-di-sodium boric acid solvate), 1.692 m2/g for catena-(tetrakis(μ2-hydroxo)-(μ2-trihydrogen borate)-(μ2-fumarato)-di-sodium boric acid solvate) and 5.600 m2/g for catena-(tetrakis(μ2-hydroxo)-(μ2-trihydrogen borate)-(μ2-acetylenedicarboxylato)-di-sodium boric acid solvate). Hydrogen storage capacities of the complexes were also studied at 77 K 1 bar pressure and found as 0.108%, 0.033%, 0.021% by mass. When different ligands were used, the pore volume, pore width and surface area of the obtained complexes were changed. As a consequence, hydrogen storage capacities also changed.

  8. Effect of boric acid mass transfer on the accumulation thereof in a fuel core under emergency modes at NPPs with WMR

    Science.gov (United States)

    Morozov, A. V.; Sorokin, A. P.; Ragulin, S. V.; Pityk, A. V.; Sahipgareev, A. R.; Soshkina, A. S.; Shlepkin, A. S.

    2017-07-01

    Boric acid mass transfer processes in the reactor facilities with WMR are considered for the case of an emergency with breaking of the main circulation pipeline (MCP) and the operation of the passive safety systems, such as first-, second-, and third-stage accumulator tank systems, and a passive heat removal system (PHRS). Calculation results are presented for a change in the boric acid concentration in the fuel core (FC) of a water-moderated reactor (WMR) in the case of an emergency process. The calculations have been performed for different values of drop entrainment of boric acid from the reactor (0, 0.2, 2%). A substantial excess of the maximum concentration of boric acid has been found to occur 24 hours after an emergency event with a break of MCP. It is shown that increasing the droplet entrainment of boric acid causes the crystallization and accumulation thereof in the FC to become slower. The mass of boric acid deposits on the elements of internals is determined depending on the values of drop entrainment. These results allow one to draw a conclusion concerning the possibility of accumulation and crystallization of boric acid in the FC, because the latter event could lead to a blocking of the flow cross section and disturbance in the heat removal from fuel elements. A review of available literature data concerning the thermal properties of boric acid solution (density, viscosity, thermal conductivity) is presented. It is found that the available data are of quite a general character, but it does not cover the entire range of parameters (temperature, pressure, acid concentrations) inherent in a possible emergency situation at nuclear power plants with WMR. It is demonstrated that experimental study of boric acid drop entrainment at the parameters inherent in the emergency mode of WMR operation, as well as the studies of boric acid thermal properties in a wide range of concentrations, are required.

  9. Determination of contaminants in boric acid used as neutron moderator by means of ion chromatography and selective electrodes

    International Nuclear Information System (INIS)

    Pires, M.A.F.; Abrao, A.

    1988-07-01

    The boric acid used as neutron moderator in reactors must observe restrictions about the concentration of some impurities. According to Westinghouse (1) specification, the highest limits for sodium, sulphate, phosphate, fluoride, and chlorine are: Na + - 0,003%; SO 4 -2 - 0,0006%; PO 4 -3 - 0,003%; F - - 0,00002%; Cl - - 0,00004%. This paper describes the determination of ions above mentioned directly in the boric acid solution. The sample is dissolved in water or in an appropriate eluent and is injected in the ion chromatograph. Na + and F - are determined by means of selective electrodes. The determination limits found for F - (0,0002%) and Cl - (0,0002%) are not sufficiently low to attent the specifications. The determination limits found for SO 4 -2 (0,0005%), PO 4 -3 (0,0003%) and Na + (0,0005%) are good enough for nuclear pure boric acid analysis. In some samples nitrate (detection limit 0,0015%) was found as well. Boric acid from different suppliers were analysed. (author) [pt

  10. Boric Acid as an Accelerator of Cerium Surface Treatment on Aluminum

    Directory of Open Access Journals (Sweden)

    K. Cruz-Hernández

    2014-01-01

    Full Text Available Aluminum pieces are often used in various industrial processes like automotive and aerospace manufacturing, as well as in ornamental applications, so it is necessary to develop processes to protect these materials, processes that can be industrialized to protect the aluminum as well or better than chromate treatments. The purpose of this research is to evaluate boric acid as an accelerator by optimizing its concentration in cerium conversion coatings (CeCC with 10-minute immersion time with a concentration of 0.1 g L−1 over aluminum to protect it. The evaluation will be carried out by measuring anticorrosion properties with electrochemical techniques (polarization resistance, Rp, polarization curves, PC, and electrochemical impedance spectroscopy, EIS in NaCl 3.5% wt. aqueous solution and surface characterization with scanning electron microscopy (SEM.

  11. Evaluation of ultrasonic technique to characterize the concentration of boric acid in liquid medium; Avaliacao de tecnica ultrassonica para medida de concentracao de acido borico em meio liquido

    Energy Technology Data Exchange (ETDEWEB)

    Kohara, Richard Yuzo Ramida

    2015-06-01

    This dissertation is to analyze the viability of using ultrasonic technique to characterize the concentration of boric acid in liquid medium non-invasively, therefore, ultrasonic tests were performed relating different boric acid concentrations with the travel time of the ultrasonic wave, also were evaluated factors able to mask the characterization of these concentrations by ultrasonic technique. The results showed that the ultrasonic technique allows the characterization of boric acid concentrations in liquid medium in very simple terms by the ultrasonic wave travel time, requiring further studies in complex conditions. (author)

  12. Boric acid as cost-effective and recyclable catalyst for trimethylsilyl protection and deprotection of alcohols and phenols

    Energy Technology Data Exchange (ETDEWEB)

    Rostami, Amin; Akradi, Jamal; Ahmad-Jangi, Firoz, E-mail: a_rostami372@yahoo.co [University of Kurdistan, Sanandaj (Iran, Islamic Republic of). Faculty of Science. Dept. of Chemistry

    2010-07-01

    Boric acid has been used as a green, selective and recyclable catalyst for trimethysilylation of alcohols and phenols using hexamethyldisilazane in acetonitrile. Deprotection of trimethylsilyl ethers to their parent alcohols and phenols was also achieved using this catalyst in water at room temperature. The salient features of this methodology are cheap processing, mild acidity conditions, excellent yields of products and easy availability of the catalyst. (author)

  13. Hierarchical porous photoanode based on acid boric catalyzed sol for dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Maleki, Khatereh [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran (Iran, Islamic Republic of); Abdizadeh, Hossein [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran (Iran, Islamic Republic of); Center of Excellence for High Performance Materials, University of Tehran, Tehran (Iran, Islamic Republic of); Golobostanfard, Mohammad Reza, E-mail: Mohammadreza.Golbostanfard@gmail.com [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran (Iran, Islamic Republic of); Adelfar, Razieh [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran (Iran, Islamic Republic of)

    2017-02-01

    Highlights: • Acid boric can thoroughly leads to the hierarchical porous titania structure. • Boron is introduced into titania lattice which causes slight blueshift of bandgap. • The optimized sol parameters are H{sub 3}BO{sub 3}/TTiP = 0.45, DI/TTiP = 4.5, and 0.17 M. • Optimized paste parameters is not changed compared to conventional pastes. • The DSSC based on H{sub 3}BO{sub 3} catalyzed sol shows promising efficiency of 2.91%. - Abstract: The hierarchical porous photoanode of the dye sensitized solar cell (DSSC) is synthesized through non-aqueous sol-gel method based on H{sub 3}BO{sub 3} as an acid catalyst and the efficiencies of the fabricated DSSC based on these photoanodes are compared. The sol parameters of 0.17 M, water mole ratio of 4.5, acid mole ratio of 0.45, and solvent type of ethanol are introduced as optimum parameters for photoanode formation without any detectable cracks. The optimized hierarchical photoanode mainly contains anatase phase with slight shift toward higher angles, confirming the doping of boron into titania structure. Moreover, the porous structure involves two ranges of average pore sizes of 20 and 635 nm. The diffuse reflectance spectroscopy (DRS) shows the proper scattering and blueshift in band gap. The paste parameters of solid:liquid, TiO{sub 2}:ethyl cellulose, and terpineol:ethanol equal to 11:89, 3.5:7.5, and 25:64, respectively, are assigned as optimized parameters for this novel paste. The photovoltaic properties of short circuit current density, open circuit voltage, fill factor, and efficiency of 5.89 mA/cm{sup 2}, 703 mV, 0.7, and 2.91% are obtained for the optimized sample, respectively. The relatively higher short circuit current of the main sample compared to other samples is mainly due to higher dye adsorption in this sample corresponding to its higher surface area and presumably higher charge transfer confirmed by low R{sub S} and R{sub ct} in electrochemical impedance spectroscopy data. Boric acid as

  14. Limitations when use chloramphenicol-bcyclodextrins complexes in ophtalmic solutions buffered with boric acid/borax system

    OpenAIRE

    Todoran Nicoleta; Ciurba Adriana; Rédai Emőke; Ion V.; Lazăr Luminița; Sipos Emese

    2014-01-01

    Chloramphenicol eye drops are commonly prescribed in concentrations of 0.5-1% in the treatment of infectious conjunctivitis. In terms of ophthalmic solution preparation, the major disadvantage of chloramphenicol consists in its low solubility in water. The solubility is increased by substances that form chloramphenicol-complexes, for example: boric acid/borax or cyclodextrins. Objective: Experimental studies aimed to evaluate the potential advantages of enhancing the solubility and stability ...

  15. Fiberboards treated with N’-N-(1, 8-Naphthalyl) hydroxylamine (NHA-Na), borax, and boric acid

    Science.gov (United States)

    Turgay Akbulut; S. Nami Kartal; Frederick Green

    2004-01-01

    This paper reports on the physical and mechanical properties and decay and termite resistance of fiberboard panels made from pine and beech treated with N’-N-(1, 8-Naphthalyl) hydroxylamine sodium salt(NHA-Na), borax, and boric acid at varying loadings. The panels were manufactured using 10 percent urea-formaldehyde resin and 1 percent NH4Cl. Mechanical and physical...

  16. Limitations when use chloramphenicol-bcyclodextrins complexes in ophtalmic solutions buffered with boric acid/borax system

    Directory of Open Access Journals (Sweden)

    Todoran Nicoleta

    2014-12-01

    Full Text Available Chloramphenicol eye drops are commonly prescribed in concentrations of 0.5-1% in the treatment of infectious conjunctivitis. In terms of ophthalmic solution preparation, the major disadvantage of chloramphenicol consists in its low solubility in water. The solubility is increased by substances that form chloramphenicol-complexes, for example: boric acid/borax or cyclodextrins. Objective: Experimental studies aimed to evaluate the potential advantages of enhancing the solubility and stability of chloramphenicol (API by molecular encapsulation in b-cyclodextrin (CD, in formulation of ophthalmic solutions buffered with boric acid/borax system. Methods and Results: We prepared four APIb- CD complexes, using two methods (kneading and co-precipitation and two molar ratio of API/b-cyclodextrin (1:1 and 1:2. The formation of complexes was proved by differential scanning calorimetry (DSC and the in vitro dissolution tests. Using these compounds, we prepared eight ophthalmic solutions, formulated in two variants of chloramphenicol concentrations (0.4% and 0.5%. Each solution was analyzed, by the official methods, at preparation and periodically during three months of storing in different temperature conditions (4°C, 20°C and 30°C. Conclusions: Inclusion of chloramphenicol in b-cyclodextrin only partially solves the difficulties due to the low solubility of chloramphenicol. The protection of chloramphenicol molecules is not completely ensured when the ophthalmic solutions are buffered with the boric acid/borax system.

  17. Boric/sulfuric acid anodizing of aluminum alloys 2024 and 7075: Film growth and corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, G.E.; Zhang, L.; Smith, C.J.E.; Skeldon, P.

    1999-11-01

    The influence of boric acid (H{sub 3}BO{sub 3}) additions to sulfuric acid (H{sub 2}SO{sub 4}) were examined for the anodizing of Al 2024-T3 (UNS A92024) and Al 7075-T6 (UNS A97075) alloys at constant voltage. Alloys were pretreated by electropolishing, by sodium dichromate (Na{sub 2}Cr{sub 2}O{sub 7})/H{sub 2}SO{sub 4} (CSA) etching, or by alkaline etching. Current-time responses revealed insignificant dependence on the concentration of H{sub 3}BO{sub 3} to 50 g/L. Pretreatments affected the initial film development prior to the establishment of the steady-state morphology of the porous film, which was related to the different compositions and morphologies of pretreated surfaces. More detailed studies of the Al 7075-T6 alloy indicated negligible effects of H{sub 3}BO{sub 3} on the coating weight, morphology of the anodic film, and thickening rate of the film, or corrosion resistance provided by the film. In salt spray tests, unsealed films formed in H{sub 2}SO{sub 4} or mixed acid yielded similar poor corrosion resistances, which were inferior to that provided by anodizing in chromic acid (H{sub 2}CrO{sub 4}). Sealing of films in deionized water, or preferably in chromate solution, improved corrosion resistance, although not matching the far superior performance provided by H{sub 2}CrO{sub 4} anodizing and sealing.

  18. Reverse osmosis for the recovery of boric acid from the primary coolant at nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bártová, Šárka, E-mail: sarka.bartova@cvrez.cz [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic); Kůs, Pavel [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic); Skala, Martin [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic); University of Chemical Technology, Prague, Department of Chemical Engineering, Technická 5, Prague 166 28 (Czech Republic); Vonková, Kateřina [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic)

    2016-04-15

    Highlights: • RO membranes tested for boric acid recovery from primary coolant of nuclear power plants. • Scanning electron microscopy was used for the characterization of the membranes. • Lab scale experiments performed under various operation conditions. • We proposed configuration of and operation conditions for RO unit in nuclear power plant. - Abstract: At nuclear power plants (NPP), evaporators are used for the treatment of primary coolant and other liquid radioactive waste containing H{sub 3}BO{sub 3}. Because the operation of evaporators is expensive, a number of more cost-effective alternatives has been considered, one of which is reverse osmosis. We tested reverse osmosis modules from several manufactures on a batch laboratory apparatus. SEM images of the tested membranes were taken to distinguish the differences between the membranes. Water permeability through membranes was evaluated from the experiments with pure water. The experiments were performed with feed solutions containing various concentrations of H{sub 3}BO{sub 3} in a range commonly occurring in radioactive waste. The pH of the feed solutions ranged from 5.2 to 11.2. Our results confirmed that the pH of the feed solution plays the most important role in membrane separation efficiency of H{sub 3}BO{sub 3}. Certain modifications to the pH of the feed solution were needed to enable the tested membranes to concentrate the H{sub 3}BO{sub 3} in the retentate stream, separate from the pure water in the permeate stream. On this basis, we propose the configuration of and operational conditions for a reverse osmosis unit at NPP.

  19. Investigation of the vaporization of boric acid by transpiration thermogravimetry and knudsen effusion mass spectrometry.

    Science.gov (United States)

    Balasubramanian, R; Lakshmi Narasimhan, T S; Viswanathan, R; Nalini, S

    2008-11-06

    The vaporization of H3BO3(s) was studied by using a commercial thermogravimetric apparatus and a Knudsen effusion mass spectrometer. The thermogravimetric measurements involved use of argon as the carrier gas for vapor transport and derivation of vapor pressures of H3BO3(g) in the temperature range 315-352 K through many flow dependence and temperature dependence runs. The vapor pressures as well as the enthalpy of sublimation obtained in this study represent the first results from measurements at low temperatures that are in accord with the previously reported near-classical transpiration measurements (by Stackelberg et al. 70 years ago) at higher temperatures (382-413 K with steam as the carrier gas). The KEMS measurements performed for the first time on boric acid showed H3BO3(g) as the principal vapor species with no meaningful information discernible on H2O(g) though. The thermodynamic parameters, both p(H3BO3) and Delta sub H degrees m(H3BO3,g), deduced from KEMS results in the temperature range 295-342 K are in excellent agreement with the transpiration results lending further credibility to the latter. All this information points toward congruent vaporization at the H3BO3 composition in the H2O-B2O3 binary system. The vapor pressures obtained from transpiration (this study and that of Stackelberg et al.) as well as from KEMS measurements are combined to recommend the following: log [p(H3BO3)/Pa]=-(5199+/-74)/(T/K)+(15.65+/-0.23), valid for T=295-413 K; and Delta sub H degrees m=98.3+/-9.5 kJ mol (-1) at T=298 K for H3BO3(s)=H3BO3(g).

  20. Intravaginal boric acid: is it an alternative therapeutic option for vaginal trichomoniasis?

    Science.gov (United States)

    Thorley, Nicola; Ross, Jonathan

    2017-12-09

    Trichomoniasis, caused by Trichomonas vaginalis (TV), is the most common curable sexually transmitted infection worldwide. Current guidance in the UK is to treat TV with a nitroimidazole antibiotic. The high prevalence of TV, high rate of antibiotic resistance and limited tolerability to nitroimidazoles suggest that alternative treatment regimens are needed. Intravaginal boric acid (BA) has been used safely for the treatment of candida vulvovaginitis and bacterial vaginosis, and in vitro studies suggest BA is active against TV. We review the evidence for the efficacy of BA in patients with TV. MEDLINE, EMBASE, CINAHL, AMED, HMIC and BNI and Grey literature databases, The Cochrane Library, Trial Registers, conference abstracts and proceedings were searched. Inclusion criteria were women aged 16 years or over with microbiological confirmation of TV infection and using BA as treatment. There were no restrictions on language, publication date or study design. The in vitro evidence for BA activity against TV was also reviewed. No randomised controlled trials or case series were found. Four case reports demonstrated TV clearance with BA using a variety of dose regimens (dose 600 mg alternate nights to 600 mg two times per day; duration 1-5 months). In vitro studies suggest that BA has activity against TV which is independent of its effect on pH. Further evaluation of BA for the treatment of uncomplicated TV is required, but it may be useful when therapeutic options are limited. If shown to be safe and effective, intravaginal BA might provide a well-tolerated alternative anti-infective treatment which reduces community exposure to systemic antibiotics. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  1. Effectiveness of 3 per cent boric acid in 70 per cent alcohol versus 1 per cent clotrimazole solution in otomycosis patients: a randomised, controlled trial.

    Science.gov (United States)

    Romsaithong, S; Tomanakan, K; Tangsawad, W; Thanaviratananich, S

    2016-09-01

    To compare the clinical effectiveness and adverse events for 3 per cent boric acid in 70 per cent alcohol versus 1 per cent clotrimazole solution in the treatment of otomycosis. A total of 120 otomycosis patients were randomly assigned to receive either 1 per cent clotrimazole solution (intervention group) or 3 per cent boric acid in 70 per cent alcohol (control group) at the Khon Kaen Hospital ENT out-patient department. Treatment effectiveness was determined based on the otomicroscopic absence of fungus one week after therapy, following a single application of treatment. After 1 week of treatment, there were data for 109 participants, 54 in the clotrimazole group and 55 in the boric acid group. The absolute difference in cure rates between 1 per cent clotrimazole solution and 3 per cent boric acid in 70 per cent alcohol was 17.9 per cent (95 per cent confidence interval, 2.3 to 33.5; p = 0.028) and the number needed to treat was 6 (95 per cent confidence interval, 3.0 to 43.4). Adverse events for the two agents were comparable. One per cent clotrimazole solution is more effective than 3 per cent boric acid in 70 per cent alcohol for otomycosis treatment.

  2. Mechanism of Early Stage Corrosion for Boric-sulfuric Acid Anodized 2A97 Al-Cu-Li Alloy Under Tropical Marine Atmosphere

    Directory of Open Access Journals (Sweden)

    LUO Chen

    2016-09-01

    Full Text Available Optical microscopy(OM, scanning electron microscopy(SEM, EDX and EIS combined with ultramicrotomy were employed to investigate the micro morphology, chemical composition and electrochemical properties of anodized 2A97 Al-Cu-Li alloy before and after atmospheric corrosion. The results show that when electrolytes containing combinations of tartaric-sulfuric or boric-sulfuric acid are used to grow the films at different temperatures, boric acid addition and higher temperature allow for higher current density that speeds up the film growth. The pore geometry and structure is similar for different electrolytes. Dispersive dark rusty spots composed of O, Al, Cl, Cu are present on the boric-sulfuric acid anodized specimen after exposure in tropical marine atmosphere for 1 month. Deposition of white corrosion product is found on the specimen surface as well. Severe pitting occurs and develops deeply into the alloy substrate after elongated outdoor exposure. Corrosion propagation is associated with θ-phase particles.

  3. Cover Picture: Metal‐Free Dehydration of Glucose to 5‐(Hydroxymethyl)furfural in Ionic Liquids with Boric Acid as a Promoter (Chem. Eur. J. 5/2011)

    DEFF Research Database (Denmark)

    Ståhlberg, Tim Johannes Bjarki; Rodriguez, Sergio; Fristrup, Peter

    2011-01-01

    Boric acid promotes the dehydration of glucose to 5-(hydroxy)methylfurfural in ionic liquids. Computational analyses by DFT calculations show a significant decrease in energy for the isomerization of glucose to fructose when the sugars are bound to boric acid and isotopic labeling NMR studies con...

  4. Theoretical isotopic fractionation between structural boron in carbonates and aqueous boric acid and borate ion

    Science.gov (United States)

    Balan, Etienne; Noireaux, Johanna; Mavromatis, Vasileios; Saldi, Giuseppe D.; Montouillout, Valérie; Blanchard, Marc; Pietrucci, Fabio; Gervais, Christel; Rustad, James R.; Schott, Jacques; Gaillardet, Jérôme

    2018-02-01

    The 11B/10B ratio in calcite and aragonite is an important proxy of oceanic water pH. However, the physico-chemical mechanisms underpinning this approach are still poorly known. In the present study, we theoretically determine the equilibrium isotopic fractionation properties of structural boron species in calcium carbonates, BO33-, BO2(OH)2- and B(OH)4- anions substituted for carbonate groups, as well as those of B(OH)4- and B(OH)3 species in vacuum. Significant variability of equilibrium isotopic fractionation properties is observed among these structural species which is related to their contrasted coordination state, Bsbnd O bond lengths and atomic-scale environment. The isotopic composition of structural boron does not only depend on its coordination number but also on its medium range environment, i.e. farther than its first coordination shell. The isotopic fractionation between aqueous species and their counterparts in vacuum are assessed using previous investigations based on similar quantum-mechanical modeling approaches. At 300 K, the equilibrium isotope composition of structural trigonal species is 7-15‰ lighter than that of aqueous boric acid molecules, whereas substituted tetrahedral borate ions are heavier than their aqueous counterparts by 10-13‰. Although significant uncertainties are known to affect the theoretical prediction of fractionation factors between solids and solutions, the usually assumed lack of isotopic fractionation during borate incorporation in carbonates is challenged by these theoretical results. The present theoretical equilibrium fractionation factors between structural boron and aqueous species differ from those inferred from experiments which may indicate that isotopic equilibrium, unlike chemical equilibrium, was not reached in most experiments. Further research into the isotopic fractionation processes at the interface between calcium carbonates and aqueous solution as well as long duration experiments aimed at

  5. Metal‐Free Dehydration of Glucose to 5‐(Hydroxymethyl)furfural in Ionic Liquids with Boric Acid as a Promoter

    DEFF Research Database (Denmark)

    Ståhlberg, Tim; Rodriguez, Sergio; Fristrup, Peter

    2011-01-01

    The dehydration of glucose and other hexose carbohydrates to 5‐(hydroxymethyl)furfural (HMF) was investigated in imidazolium‐based ionic liquids with boric acid as a promoter. A yield of up to 42 % from glucose and as much as 66 % from sucrose was obtained. The yield of HMF decreased as the conce......The dehydration of glucose and other hexose carbohydrates to 5‐(hydroxymethyl)furfural (HMF) was investigated in imidazolium‐based ionic liquids with boric acid as a promoter. A yield of up to 42 % from glucose and as much as 66 % from sucrose was obtained. The yield of HMF decreased...

  6. The effects of dietary boric acid and borax supplementation on lipid peroxidation, antioxidant activity, and DNA damage in rats.

    Science.gov (United States)

    Ince, Sinan; Kucukkurt, Ismail; Cigerci, Ibrahim Hakki; Fatih Fidan, A; Eryavuz, Abdullah

    2010-07-01

    The aims of this study were to clarify the effects of high dietary supplementation with boric acid and borax, called boron (B) compounds, on lipid peroxidation (LPO), antioxidant activity, some vitamin levels, and DNA damage in rats. Thirty Sprague Dawley male rats were divided into three equal groups: the animals in the first group (control) were fed with a standard rodent diet containing 6.4 mg B/kg, and the animals in the experimental group were fed with a standard rodent diet added with a supra-nutritional amount of boric acid and borax (100 mg B/kg) throughout the experimental period of 28 days. The B compounds decreased malondialdehyde (MDA), DNA damage, the protein carbonyl content (PCO) level in blood, and glutathione (GSH) concentration in the liver, Cu-Zn superoxide dismutase (SOD), and catalase (CAT) activity in the kidney. The B compounds increased GSH concentration in blood and the vitamin C level in plasma. Consequently, our results demonstrate that B supplementation (100 mg/kg) in diet decreases LPO, and enhances the antioxidant defense mechanism and vitamin status. There are no differences in oxidant/antioxidant balance and biochemical parameters except for serum vitamin A and liver GSH concentration, between the boron compounds used in this study. Crown Copyright 2010. Published by Elsevier GmbH. All rights reserved.

  7. Simultaneous pollutant removal and electricity generation in denitrifying microbial fuel cell with boric acid-borate buffer solution.

    Science.gov (United States)

    Chen, Gang; Zhang, Shaohui; Li, Meng; Wei, Yan

    2015-01-01

    A double-chamber denitrifying microbial fuel cell (MFC), using boric acid-borate buffer solution as an alternative to phosphate buffer solution, was set up to investigate the influence of buffer solution concentration, temperature and external resistance on electricity generation and pollutant removal efficiency. The result revealed that the denitrifying MFC with boric acid-borate buffer solution was successfully started up in 51 days, with a stable cell voltage of 205.1 ± 1.96 mV at an external resistance of 50 Ω. Higher concentration of buffer solution favored nitrogen removal and electricity generation. The maximum power density of 8.27 W/m(3) net cathodic chamber was obtained at a buffer solution concentration of 100 mmol/L. An increase in temperature benefitted electricity generation and nitrogen removal. A suitable temperature for this denitrifying MFC was suggested to be 25 °C. Decreasing the external resistance favored nitrogen removal and organic matter consumption by exoelectrogens.

  8. Synthesis of PBAD-lipiodol nanoparticles for combination treatment with boric acid in boron neutron capture therapy for hepatoma in-vitro

    International Nuclear Information System (INIS)

    Chou, F.I.; Chung, H.P.; Liu, H.M.; Wen, H.W.; Chi, C.W.; Lin, Shanyang; Lui, W.Y.; Kai, J.J.

    2006-01-01

    This study attempted to increase BNCT efficiency for hepatoma by a combined treatment of phenylboric acid derivative entrapped lipiodol nanoparticles (PBAD-L nanoparticles) with boric acid. The size of PBAD-L nanoparticles were 400-750 nm at the boron concentrations of 0.3-2.7 mg/ml. After 24 hours the boron concentration in PBAD-L nanoparticles treated human hepatoma HepG2 cells was 112 ppm, while that in rat liver Clone 9 cells was 52 ppm. With the use of 25 μg B/ml boric acid, after 6 hours the boron concentration in HepG2 and Clone 9 cells were 75 ppm and 40 ppm, respectively. In a combined treatment, boron concentration in HepG2 cells which were treated with PBAD-L nanoparticles for 18 hours and then combined with boric acid for 6 hours was 158 ppm. After neutron irradiation, the surviving fraction of HepG2 cells treated with PBAD-L nanoparticles was 12.6%, while that in the ones with a combined treatment was 1.3%. In conclusion, the combined treatment provided a higher boron concentration in HepG2 cells than treatments with either PBAD-L nanoparticles or boric acid, resulting in a higher therapeutic efficacy of BNCT in hepatoma cells. (author)

  9. Model for conductometric detection of carbohydrates and alcohols as complexes with boric acid and borate ion in high-performance liquid chromatography

    International Nuclear Information System (INIS)

    Bertrand, G.L.; Armstrong, D.W.

    1989-01-01

    In recent articles, Okada has demonstrated the utility of indirect conductometric detection of electrically neutral sugars and alcohols through their complexes in boric acid solution. The use of a boric acid eluent provides a highly sensitive means of detection for monosaccharides, lactose, and sugar alcohols but not for polysaccharides (other than lactose) and simple alcohols. Addition of sorbitol, mannitol, or fructose to the boric acid eluent allows detection of the polysaccharides and simple alcohols, as well as lactose, glucose, fructose, and presumably other monosaccharides and sugar alcohols. These results were interpreted in terms of the ability of an analyte to form either dissociated or undissociated complexes with boric acid. This interpretation was quantified with a mathematical description of the complexation equilibria and the conductivity due to ionic species. Unfortunately, the mathematical model contains some incorrect assumptions that severely limit the utility of the derived equations and may prevent optimization of this potentially important technique. We present here a more general mathematical model that does not suffer from these limitations

  10. Method for the reprocessing of liquid wastes containing boric acid, radioactive antimony and other radioactive nuclides and similar, especially of the evaporator concentrates of nuclear power plants

    International Nuclear Information System (INIS)

    Doerr, A.

    1978-01-01

    The liquid wastes are evaporated, H 2 SO 4 and methanol are added, and the formed boric acid methylester is distilled off. The residue with Sb-124, Cs, Co and Mn is then stored two years until the activity of Sb-124 has decayed. Afterwards the radioactive nuclides are precipitated. (DG) [de

  11. The Usability of Boric Acid as an Alternative Foaming Agent on the Fabrication of Al/Al2O3 Composite Foams

    Science.gov (United States)

    Yaman, Bilge; Onuklu, Eren; Korpe, Nese O.

    2017-09-01

    Pure Al and alumina (2, 5, 10 wt.% Al2O3)-added Al composite foams were fabricated through powder metallurgy technique, where boric acid (H3BO3) is employed as a new alternative foaming agent. It is aimed to determine the effects of boric acid on the foaming behavior and cellular structure and also purposed to develop the mechanical properties of Al foams by addition of Al2O3. Al and Al composite foams with porosity fraction in the range of 46-53% were achieved by sintering at 620 °C for 2 h. Cell morphology was characterized using a combination of stereomicroscope equipped with image analyzer and scanning electron microscopy. Microhardness values were measured via using Vickers indentation technique. Quasi-static compression tests were performed at strain rate of 10-3 s-1. Compressive strength and energy absorption of the composite foams enhanced not only by the increasing weight fraction of alumina, but also by the usage of boric acid which leads to formation of boron oxide (B2O3) acting as a binder in obtaining dense cell walls. The results revealed that the boric acid has outstanding potential as foaming agent in the fabrication of Al and Al composite foams by providing improved mechanical properties.

  12. Synthesis of 1-amidoalkyl-2-naphthols based on a three-component reaction catalyzed by boric acid as a solid heterogeneous catalyst under solvent-free conditions

    Directory of Open Access Journals (Sweden)

    Zahed Karimi-Jaberi

    2012-12-01

    Full Text Available An efficient method for the preparation of 1-amidoalkyl-2-naphthols has been described using a multi-component, one-pot condensation reaction of 2-naphthol, aldehydes and amides in the presence of boric acid under solvent-free conditions.DOI: http://dx.doi.org/10.4314/bcse.v26i3.18

  13. The Effect of Boric Acid and Borax on Oxidative Stress, Inflammation, ER Stress and Apoptosis in Cisplatin Toxication and Nephrotoxicity Developing as a Result of Toxication.

    Science.gov (United States)

    Hazman, Ömer; Bozkurt, Mehmet Fatih; Fidan, Abdurrahman Fatih; Uysal, Fadime Erkan; Çelik, Sefa

    2018-03-02

    The development of treatment protocols that can reduce side effects in chemotherapy applications is extremely important in terms of cancer treatment. In this context, it was aimed to investigate the effects of boric acid and borax on cisplatin toxicity (nephrotoxicity) in rats. In the experimental phase, eight groups were formed from rats. Boric acid and borax were given to the treatment groups with three different doses using gavage. On the fifth day of the study, cisplatin (10 mg/kg) was administered to all rats except the control group. At the end of the study, oxidative stress-related (GSH, MDA, PCO, GPx, 8-OHdG), inflammation-related (TNF-α, IL-1β, IL-18, MCP-1, ICAM, TGF-β), apoptosis-related (p53, caspase 1, 3, 8, 12, bcl-2, bcl-xL, NFkB), and ER stress-related (GRP78, ATF-6, PERK) basic parameters were analyzed in serum, erythrocyte, and kidney tissues. Kidney tissues were also examined by histopathological and immunohistochemical methods. Borax and boric acid at different doses decreased inflammation and oxidative stress caused by cisplatin toxicity and increased ER stress. As a result of the treatments applied to experimental animals, it was determined that boric acid and borax reduced apoptotic damage in kidney tissue, but the decrease was statistically significant only in 200 mg/kg boric acid-administered group. In the study, low anti-apoptotic effects of borate doses with the anti-inflammatory and antioxidant effect may be due to increased ER stress at the relevant doses. Further studies on the effects of boron compounds on ER stress and apoptotic mechanisms may clarify this issue. Thus, possible side effects or if there are new usage areas of borone compounds which have many usage areas in clinics can be detected.

  14. Determination of boron as boric acid by automatic potentiometric titration using Gran plots [in pressurized water reactor coolant

    International Nuclear Information System (INIS)

    Midgley, D.; Gatford, C.

    1989-11-01

    Boron in PWR primary coolant and related waters may be determined as boric acid by titration with sodium hydroxide, using a glass electrode as a pH indicator. Earlier work has shown that this analysis can conveniently be carried out automatically with adequate precision and accuracy for routine use, although bias became apparent at the lowest concentrations tested. The latest titrators enable the titration data to be transformed mathematically to give two linear segments, before and after the end-point (Gran plots). The results are as precise as those from other titration methods (in which the end-point is found from the point of inflexion of a plot of pH against volume of titrant), but the bias at low concentrations is much reduced. This is achieved without extra time or involvement of the operator. (author)

  15. Importance of temperature, pH, and boric acid concentration on rates of hydrogen production from galvanized steel corrosion

    International Nuclear Information System (INIS)

    Loyola, V.M.

    1982-01-01

    One of the known sources of hydrogen gas within a nuclear plant containment building during a LOCA is the high temperature corrosion of galvanized steel yielding hydrogen gas. The importance of this source of hydrogen will vary depending on the severity of the accident. In an accident which resulted in core degradation, for example, the major source of hydrogen would probably be the metal-water reaction of the zircaloy cladding, and the corrosion of galvanized steel would then become a relatively minor source of hydrogen. However, in an accident in which core degradation is avoided or limited to minor damage, the corrosion of galvanized steel, and presumably of other materials as well, would then become a major contributor to the buildup of hydrogen within containment. The purpose of this paper is to present the overall effects of temperature, pH, and boric acid concentration on the rate of hydrogen generation over a broad range of each parameter

  16. Effects of sublethal exposure to boric acid sugar bait on adult survival, host-seeking, bloodfeeding behavior, and reproduction of Stegomyia albopicta.

    Science.gov (United States)

    Ali, Arshad; Xue, Rui-De; Barnard, Donald R

    2006-09-01

    Effects of sublethal exposure to 0.1% boric acid sugar bait on adult survival, host-seeking, bloodfeeding behavior, and reproduction of Stegomyia albopicta were studied in the laboratory. Survival of males as well as females was significantly reduced when exposed to the bait, compared to control adults. The host-seeking and bloodfeeding activities in the baited females decreased, but the mean duration of blood engorgement (probing to voluntary withdrawal of proboscis) was not significantly different between the baited and control females. The landing and biting rates (human forearm) were significantly reduced in the baited females compared to nonbaited controls. Fecundity and fertility (based on number of laid eggs per female and percentage egg hatch, respectively) in the baited females were significantly reduced, and ovarian development was retarded. Sublethal exposure to sugar-based boric acid bait has the potential to reduce adult populations of St. albopicta.

  17. Update of the water chemistry effect on the flow-accelerated corrosion rate of carbon steel: influence of hydrazine, boric acid, ammonia, morpholine and ethanolamine

    International Nuclear Information System (INIS)

    Pavageau, E.-M.; De Bouvier, O.; Trevin, S.; Bretelle, J.-L.; Dejoux, L.

    2007-01-01

    The influence of the water chemistry on Flow-Accelerated Corrosion (FAC) affecting carbon steel components has been studied for many years and is relatively well known and taken into account by the models. Nonetheless, experimental studies were conducted in the last few years at EDF on the CIROCO loop in order to check the influence of the water chemistry parameters (hydrazine, boric acid, ammonia, morpholine and ethanolamine) on the FAC rate of carbon steel in one phase flow conditions. The hydrazine impact on the FAC rate was shown to be minor in EDF's chemistry recommendation range, compared to other parameters' effects such as the pH effect. The presence of boric acid in the nominal secondary circuit conditions was negligible. Finally, as expected, the nature of the chemical conditioning (ammonia, morpholine or ethanolamine) did not modify the FAC rate, the influencing chemical variable being the at-temperature pH in one-phase flow conditions. (author)

  18. Reconstitution of Vanadium Haloperoxidase's Catalytic Activity by Boric Acid-Towards a Potential Biocatalytic Role of Boron.

    Science.gov (United States)

    Natalio, Filipe; Wiese, Stefanie; Brandt, Wolfgang; Wessjohann, Ludger

    2017-04-11

    Boron's unusual properties inspired major advances in chemistry. In nature, the existence and importance of boron has been fairly explored (e.g. bacterial signaling, plant development) but its role as biological catalyst was never reported. Here, we show that boric acid [B(OH) 3 ] can restore chloroperoxidase activity of Curvularia inaequalis recombinant apo-haloperoxidase's (HPO) in the presence of hydrogen peroxide and chloride ions. Molecular modeling and semi-empirical PM7 calculations support a thermodynamically highly favored (bio)catalytic mechanism similarly to vanadium haloperoxidases (V-HPO) in which [B(OH) 3 ] is assumedly located in apo-HPO's active site and a monoperoxyborate [B(OH) 3 (OOH) - ] intermediate is formed and stabilized by interaction with specific active site amino acids leading ultimately to the formation of HOCl. Thus, B(OH) 3 -HPO provides the first evidence towards the future exploitation of boron's role in biological systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Evaluating 10B-enriched Boric Acid, Bromide, and Heat as Tracers of Recycled Groundwater Flow near MAR Operations

    Science.gov (United States)

    Becker, T.; Clark, J. F.

    2012-12-01

    County, CA, USA) has been in progress since September 6, 2011, following injection of boric acid enriched in boron-10 (10B) and bromide (Br-) tracers. Tracer concentrations are collected at 9 monitoring wells that have pre-experiment estimated travel times between 0.5 to 180 days. Results indicate that 10B-enriched boric acid is an effective deliberate tracer at MAR sites; however, the ion's movement is slightly retarded relative to bromide by the substrate. 10B/Br- travel time ratios range from 1 to 1.4. In addition to the two deliberate geochemical tracers, heat is being evaluated as a possible intrinsic tracer at MAR sites. At the time of the experiment (late summer), reclaimed water was significantly warmer (~20°F) than the native groundwater as it entered the system. Time series are developed from loggers outfitted at each monitoring well, with measurements recorded hourly accurate to one thousandth of a degree. Results are similar to 10B & Br- travel times and validate the potential of heat as an intrinsic tracer.

  20. Interaction of sodium monoborate and boric acid with some mono- and disaccharides in aqueous solutions (from data on isomolar solutions method)

    International Nuclear Information System (INIS)

    Shvarts, E.M.; Ignash, R.T.; Belousova, R.G.

    2000-01-01

    Interaction of sodium monoborate Na[B(OH) 4 ] and boric acid with D-glucose, D-fructose, D-saccharose and D-lactose in aqueous solution depending on the solution total concentration is studied through the method of isomolar solutions with application of conductometry and polarimetry. It is shown by the D-glucose and D-fructose examples that the method of isomolar solutions leads to results compatible with the data obtained by other methods and it may be applied to other saccharides [ru

  1. The use of Zeolite into the controlling of Lithium concentration in the PWR primary water coolant (I) : the influences of Ca, Mg and Boric Acid concentration into the exchanges capacity of Ammonium Zeolite

    International Nuclear Information System (INIS)

    Sumijanto; Siti-Amini

    1996-01-01

    In this first part of research, the influences of calsium, magnesium and boric acid concentrations to the zeolite uptake of lithium in the PWR primary water coolant have been studied. The ammonium form of zeolite was found by modification of the natural zeolite which was originated from Bayah. The results showed that the boric acid concentration in the normal condition of PWR operation absolutely did not affects the lithium uptake. The Li uptake efficiency was influenced by the presence of Ca and Mg ions in order to the presence of cations competition which was dominated by Ca ion

  2. An assessment of boric acid and borax using the IEHR Evaluative Process for Assessing Human Developmental and Reproductive Toxicity of Agents. Expert Scientific Committee.

    Science.gov (United States)

    Moore, J A

    1997-01-01

    Boron is a ubiquitous element widely distributed in nature in the form of borates at low concentrations in soils and rocks. Boron is released from these minerals by the natural weathering processes in the form of boric acid, which is water soluble and biologically available. High levels of boric acid are naturally found in sea water. Boric acid and borax are used in the greatest quantities and represent the major boron chemical exposures to humans and the environment. The principal use of boric acid and borax is in the manufacture of various types of glass products that do not result in exposure to the consumer. Boric acid and borax are also found in an array of consumer goods including fireproofing for fabrics and wood, insecticides, and in many cosmetics and personal care products as well. Boron may be an essential element for higher animals including humans. Boric acid and borax are considered to be completely absorbed by the oral route of exposure. Absorption through intact skin is considered negligible, although absorption can occur through denuded or irritated skin. Boron levels in the body do not persist upon cessation of exposure. People may be exposed to boron through three primary sources: 1) consumption of private, municipal, or commercial (bottled) sources of drinking water; 2) dietary consumption of crops and other foodstuffs (including dietary supplements for body building); and 3) inhalation of boron compounds during their mining, manufacturing, and other industrial processing. While boron has been detected in 81.8% of the municipal water systems, it is a minor source of boron in most parts of the U.S. The mean boron concentration is reported as 0.2 mg B/L. However, residents of California and other western states with boron-rich geologic deposits may be regularly exposed to higher levels in drinking water. Individuals who drink bottled mineral water may also increase their exposure to boron. An EPA health advisory, recommends boron concentrations in

  3. Fabrication of Li{sub 2}TiO{sub 3} pebbles using PVA–boric acid reaction for solid breeding materials

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yi-Hyun, E-mail: yhpark@nfri.re.kr; Cho, Seungyon; Ahn, Mu-Young

    2014-12-15

    Highlights: • Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by the slurry droplet wetting method. • Boron was used as hardening agent of PVA and completely removed during sintering. • Microstructure of fabricated Li{sub 2}TiO{sub 3} pebble was exceptionally homogeneous. • Suitable process conditions for high-quality Li{sub 2}TiO{sub 3} pebble were summarized. - Abstract: Lithium metatitanate (Li{sub 2}TiO{sub 3}) is a candidate breeding material of the Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM). The breeding material is used in pebble-bed form to reduce the uncertainty of the interface thermal conductance. In this study, Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by the slurry droplet wetting method using the cross-linking reaction between polyvinyl alcohol (PVA) and boric acid. The effects of fabrication parameters on the shaping of Li{sub 2}TiO{sub 3} green body were investigated. In addition, the basic characteristics of the sintered pebble were also evaluated. The shape of Li{sub 2}TiO{sub 3} green bodies was affected by slurry viscosity, PVA content and boric acid content. The grain size and average crush load of sintered Li{sub 2}TiO{sub 3} pebble were controlled by the sintering time. The boron was completely removed during the final sintering process.

  4. Effects of Induction Heat Bending and Heat Treatment on the Boric Acid Corrosion of Low Alloy Steel Pipe for Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki-Tae; Kim, Young-Sik [Andong National University, Gyeongbuk (Korea, Republic of); Chang, Hyun-Young; Park, Heung-Bae [KEPCO EandC, Gyeongbuk (Korea, Republic of); Sung, Gi-Ho; Shin, Min-Chul [Sungil SIM Co. Ltd, Busan (Korea, Republic of)

    2016-11-15

    In many plants, including nuclear power plants, pipelines are composed of numerous fittings such as elbows. When plants use these fittings, welding points need to be increased, and the number of inspections also then increases. As an alternative to welding, the pipe bending process forms bent pipe by applying strain at low or high temperatures. This work investigates how heat treatment affects on the boric acid corrosion of ASME SA335 Gr. P22 caused by the induction heat bending process. Microstructure analysis and immersion corrosion tests were performed. It was shown that every area of the induction heat bent pipe exhibited a high corrosion rate in the boric acid corrosion test. This behavior was due to the enrichment of phosphorous in the ferrite phase, which occurred during the induction heat bending process. This caused the ferrite phase to act as a corrosion initiation site. However, when re-heat treatment was applied after the bending process, it enhanced corrosion resistance. It was proved that this resistance was closely related to the degree of the phosphorus segregation in the ferrite phase.

  5. The Effects of Foliar Application of Urea, Calcium Nitrate and Boric Acid on Growth and Yield of Greenhouse Cucumber (cv. Khassib

    Directory of Open Access Journals (Sweden)

    Naser Nasrolahzadehasl

    2017-10-01

    Full Text Available Introduction: Cucumis sativus L. is one of the most eminent and consuming vegetables which is widely cultivated in the Middle East. Using the controlled and greenhouse cultivation is one of the most appropriate methods to increase production per unit area. In this method, controlling the effective factors of production such as plant nutrition is the important factor to achieve high performance. Besides the accuracy applied in nutritional regulation of plant roots (both in soil and hypothermic environments, in many cases, foliar nutrition is considered by breeder of greenhouse productions. Foliar nutrition is more effective on young leaves, and deficiency of macro and micro nutrients can be removed by this factor. Khassib is one of the most important cultivar of greenhouse cucumber which is widely cultivated in Iran. The present study was conducted to evaluate the effect of foliar application on greenhouse cucumber. Materials and Methods: The experiment was performed on greenhouse cucumber (cv. Khassib for five months (from March 2007 to July 2008 in Ziba Dasht Technical Instruction Center which is located near Karaj, Iran. For this reason the experiment was conducted based on split-split-plot design with three replications. Eight experimental treatments were applied for foliar application including U1C1B1: urea + calcium nitrate +boric acid, U1C1B0: urea + calcium nitrate, U1C0B1: urea + boric acid, U1C0B0: urea, U0C1B1: calcium nitrate + boric acid, U0C1B0: calcium nitrate, U0C0B1: boric acid, U0C0B0: control. The effects of urea, calcium nitrate and boric acid in concentrations 3, 10 and 0.5 (gL-1 respectively on qualitative and quantitative characteristics of greenhouse cucumber, including fruit yield, yield of first class fruit, number of fruits, percentage of first class fruit, fruits T.S.S, plant length, percentage of leaf dry matter, and leaf weight ratio were studied. Results and Discussion: The results showed that calcium nitrate had a

  6. Stability of Hydrogen-Bonded Supramolecular Architecture under High Pressure Conditions: Pressure-Induced Amorphization in Melamine-Boric Acid Adduct

    International Nuclear Information System (INIS)

    Wang, K.; Duan, D.; Wang, R.; Lin, A.; Cui, Q.; Liu, B.; Cui, T.; Zou, B.; Zhang, X.

    2009-01-01

    The effects of high pressure on the structural stability of the melamine-boric acid adduct (C3N6H6 2H3BO3, M 2B), a three-dimensional hydrogen-bonded supramolecular architecture, were studied by in situ synchrotron X-ray diffraction (XRD) and Raman spectroscopy. M 2B exhibited a high compressibility and a strong anisotropic compression, which can be explained by the layerlike crystal packing. Furthermore, evolution of XRD patterns and Raman spectra indicated that the M 2B crystal undergoes a reversible pressure-induced amorphization (PIA) at 18 GPa. The mechanism for the PIA was attributed to the competition between close packing and long-range order. Ab initio calculations were also performed to account for the behavior of hydrogen bonding under high pressure.

  7. Effect of boric acid composition on the properties of ZnO thin film nanotubes and the performance of dye-sensitized solar cell (DSSC)

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, M.Y.A., E-mail: mohd.yusri@ukm.edu.my; Roza, L.; Umar, A.A., E-mail: akrajas@ukm.edu.my; Salleh, M.M.

    2015-11-05

    The effect of boric acid (H{sub 3}BO{sub 3}) composition at constant concentration of hexamethylenetetramine (HMT) and zinc nitrate (Zn(NO{sub 3}){sub 2}) on the morphology, thickness, elemental composition, optical absorption, structure, photoluminescence of ZnO nanotubes has been investigated. The performance of the DSSC utilizing the ZnO samples has also been studied. It was found that the structure, thickness, elemental composition, optical absorption and morphology of ZnO nanostructure are significantly affected by the concentration of H{sub 3}BO{sub 3}. The diameter and thickness of ZnO nanotubes decreases as the composition of H{sub 3}BO{sub 3} increases. The DSSC utilizing ZnO nanotubes synthesized at 2 wt. % H{sub 3}BO{sub 3} performs the highest J{sub SC} and η of 2.67 mA cm{sup −2} and 0.29%, respectively. The highest performance of the device is due to the highest optical absorption of ZnO nanotubes sample and lowest charge interfacial resistance. - Graphical abstract: Nyquist plots of the DSSCs utilizing ZnO nanotubes prepared at various boric acid compositions. - Highlights: • Boron was doped into ZnO films by adding H{sub 3}BO{sub 3} into the growth solution. • Diameter and thickness of ZnO nanotubes decreases with the composition of H{sub 3}BO{sub 3}. • The DSSC performs the highest J{sub SC} and η of 2.67 mA cm{sup −2} and 0.29%, respectively. • This is due to high specific surface area and low charge interfacial resistance.

  8. In vivo percutaneous absorption of boric acid, borax, and disodium octaborate tetrahydrate in humans compared to in vitro absorption in human skin from infinite and finite doses.

    Science.gov (United States)

    Wester, R C; Hui, X; Hartway, T; Maibach, H I; Bell, K; Schell, M J; Northington, D J; Strong, P; Culver, B D

    1998-09-01

    Literature from the first half of this century report concern for toxicity from topical use of boric acid, but assessment of percutaneous absorption has been impaired by lack of analytical sensitivity. Analytical methods in this study included inductively coupled plasma-mass spectrometry which now allows quantitation of percutaneous absorption of 10B in 10B-enriched boric acid, borax, and disodium octaborate tetrahydrate (DOT) in biological matrices. This made it possible, in the presence of comparatively large natural dietary boron intakes for the in vivo segment of this study, to quantify the boron passing through skin. Human volunteers were dosed with 10B-enriched boric acid, 5.0%, borax, 5.0%, or disodium octaborate tetrahydrate, 10%, in aqueous solutions. Urinalysis, for boron and changes in boron isotope ratios, was used to measure absorption. Boric acid in vivo percutaneous absorption was 0.226 (SD = 0.125) mean percentage dose, with flux and permeability constant (Kp) calculated at 0.009 microgram/cm2/h and 1.9 x 10(-7) cm/h, respectively. Borax absorption was 0.210 (SD = 0.194) mean percentage of dose, with flux and Kp calculated at 0.009 microgram/cm2/h and 1.8 x 10(-7) cm/h, respectively. DOT absorption was 0.122 (SD = 0.108) mean percentage, with flux and Kp calculated at 0.01 microgram/cm2/h and 1.0 x 10(-7) cm/h, respectively. Pretreatment with the potential skin irritant 2% sodium lauryl sulfate had no effect on boron skin absorption. In vitro human skin percentage of doses of boric acid absorbed were 1.2 for a 0.05% solution, 0.28 for a 0.5% solution, and 0.70 for a 5.0% solution. These absorption amounts translated into flux values of, respectively, 0.25, 0.58, and 14.58 micrograms/cm2/h and permeability constants (Kp) of 5.0 x 10(-4), 1.2 x 10(-4), and 2.9 x 10(-4) cm/h for the 0.05, 0.5, and 5.0% solutions. The above in vitro doses were at infinite, 1000 microliters/cm2 volume. At 2 microliters/cm2 (the in vivo dosing volume), flux decreased some

  9. Experimental Investigations to Enhance the Tribological Performance of Engine Oil by Using Nano-Boric Acid and Functionalized Multiwalled Carbon Nanotubes: A Comparative Study to Assess Wear in Bronze Alloy

    Science.gov (United States)

    Ajay Vardhaman, B. S.; Amarnath, M.; Ramkumar, J.; Rai, Prabhat K.

    2018-04-01

    In various mechanical systems, lubricants are generally used to reduce friction and wear; thus, the total energy loss in the mechanical systems can be minimized by the proper enhancement of lubrication properties. In general, friction modifiers and antiwear additives are used to improve the tribological properties of the lubricant. However, the use of these additives has to be phased out due to their fast chemical degradation in their applications and other environmental issues. In recent years, the use of nanoparticles as a potential lubricant additive has received considerable attention because of its excellent mechanical and tribological characteristics. The present work describes the tribological behavior of nano-boric acid, multiwalled carbon nanotubes (MWCNTs), and functionalized multiwalled carbon nanotubes (FMWCNTs) modified with carboxylic acid. These nanoparticles were used to enhance the tribological properties of engine oil (SAE20W40) used to lubricate bronze alloy samples. The performance of these nano-coolants was assessed on a linear reciprocating ball-on-flat tribometer. Results highlight the friction and wear behavior of the nano-boric acid, MWCNTs, and FMWCNTs under three varying parameters such as the effect of nanoparticles concentration, load-carrying capacity, and sliding speed. The addition of nano-boric acid, MWCNTs, and FMWCNTs has significantly improved the tribological properties of the base lubricant. The addition of 0.5 wt.% of nano-boric acid, MWCNTs, and FMWCNTs to the base lubricant has decreased the coefficient of friction by 19.76, 30.55, and 35.65%, respectively, and a significant reduction in wear volume by 55.17, 71.42, and 88.97% was obtained in comparison with base lubricant.

  10. Synthesis, characterization and fuel cell performance tests of boric acid and boron phosphate doped, sulphonated and phosphonated poly(vinyl alcohol) based composite membranes

    Science.gov (United States)

    Şahin, Alpay; Ar, İrfan

    2015-08-01

    The aim of this study is to synthesize a composite membrane having high proton conductivity, ion exchange capacity and chemical stability. In order to achieve this aim, poly(vinyl alcohol) (PVA) based composite membranes are synthesized by using classic sol-gel method. Boric acid (H3BO3) and boron phosphate (BPO4) are added to the membrane matrix in different ratios in order to enhance the membrane properties. Characterization tests, i.e; FT-IR analysis, mechanical strength tests, water hold-up capacities, swelling properties, ion exchange capacities, proton conductivities and fuel cell performance tests of synthesized membranes are carried out. As a result of performance experiments highest performance values are obtained for the membrane containing 15% boron phosphate at 0.6 V and 750 mA/cm2. Water hold-up capacity, swelling ratio, ion exchange capacity and proton conductivity of this membrane are found as 56%, 8%, 1.36 meq/g and 0.37 S/cm, respectively. These values are close to the values obtained ones for perfluorosulphonic acid membranes. Therefore this membrane can be regarded as a promising candidate for usage in fuel cells.

  11. Spectroscopic quantification of 5-hydroxymethylcytosine in genomic DNA using boric acid-functionalized nano-microsphere fluorescent probes.

    Science.gov (United States)

    Chen, Hua-Yan; Wei, Jing-Ru; Pan, Jiong-Xiu; Zhang, Wei; Dang, Fu-Quan; Zhang, Zhi-Qi; Zhang, Jing

    2017-05-15

    5-hydroxymethylcytosine (5hmC) is the sixth base of DNA. It is involved in active DNA demethylation and can be a marker of diseases such as cancer. In this study, we developed a simple and sensitive 2-(4-boronophenyl)quinoline-4-carboxylic acid modified poly (glycidyl methacrylate (PBAQA-PGMA) fluorescent probe to detect the 5hmC content of genomic DNA based on T4 β-glucosyltransferase-catalyzed glucosylation of 5hmC. The fluorescence-enhanced intensity recorded from the DNA sample was proportional to its 5-hydroxymethylcytosine content and could be quantified by fluorescence spectrophotometry. The developed probe showed good detection sensitivity and selectivity and a good linear relationship between the fluorescence intensity and the concentration of 5 hmC within a 0-100nM range. Compared with other fluorescence detection methods, this method not only could determine trace amounts of 5 hmC from genomic DNA but also could eliminate the interference of fluorescent dyes and the need for purification. It also could avoid multiple labeling. Because the PBAQA-PGMA probe could enrich the content of glycosyl-5-hydroxymethyl-2-deoxycytidine from a complex ground substance, it will broaden the linear detection range and improve sensitivity. The limit of detection was calculated to be 0.167nM after enrichment. Furthermore, the method was successfully used to detect 5-hydroxymethylcytosine from mouse tissues. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Evaluation of a Solid Dispersion of Curcumin With Polyvinylpyrrolidone and Boric Acid Against Salmonella Enteritidis Infection and Intestinal Permeability in Broiler Chickens: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Daniel Hernandez-Patlan

    2018-06-01

    Full Text Available In the present study, in vitro assays were conducted to evaluate the solubility of curcumin (CUR alone or with polyvinylpyrrolidone (PVP at different pH, as well as its permeability in Caco-2 cells. Results confirmed that the solid dispersion of CUR with PVP (CUR/PVP at a 1:9 ratio, significantly increased (P < 0.05 solubility and permeability compared to CUR alone. Then, the antimicrobial activity of CUR/PVP, boric acid (BA, and a combination of 0.5% CUR/PVP and 0.5% BA (CUR/PVP-BA against Salmonella Enteritidis (SE was determined using an in vitro digestion model that simulates crop, proventriculus, and intestine. The results revealed that in the proventriculus and intestinal compartments significant reductions of SE were observed in all the experimental treatments, but 1% BA eliminated SE in the intestinal compartment and CUR/PVP-BA showed a synergistic effect on antimicrobial activity against SE. To complement these findings, two independent in vivo trials were conducted to determine the effect of 0.1% CUR/PVP; 0.1% BA; or the combination of 0.05% CUR/PVP (1:9 ratio and 0.05% BA (CUR/PVP-BA on the antimicrobial activity against SE, intestinal permeability and inflammatory responses in broiler chickens. BA at 0.1% had no significant in vivo effects against SE. However, the combination of 0.05% BA and 0.05% CUR/PVP and 0.05% BA was sufficient to reduce crop and intestinal SE colonization in broiler chickens in two independent trials, confirming the synergic effect between them. A similar antimicrobial impact against SE intestinal colonization was observed in chickens treated with 0.1% CUR/PVP at a 1:9 ratio, which could be due to the increase in solubility of CUR by PVP. Furthermore, 0.1% CUR/PVP reduced the intestinal permeability of FITC-d and total intestinal IgA, as well as increase the activity of SOD when compared to control, while, CUR/PVP-BA only decreased SOD activity. Further studies to confirm and expand the in vivo results obtained

  13. Influences of boric acid and lithium hydroxide on oxide film of type 316 stainless steel in PWR simulated primary water; PWR 1次冷却材模擬環境中の316ステンレス鋼に生成した皮膜性状に及ぼすほう酸および水酸化リチウムの影響

    Energy Technology Data Exchange (ETDEWEB)

    Fukumura, Takuya; Fukuya, Koji; Arioka, Koji [Institute of Nuclear Safety System, Inc., Mihama, Fukui (Japan)

    2012-06-15

    In order to understand the influences of boric acid and lithium hydroxide on the IGSCC of type 316 stainless steel, an oxide film was analyzed in simulated PWR primary water while varying the boric acid and lithium hydroxide concentrations. It was found that, although boric acid and lithium hydroxide did not affect the structure and chemical composition of the surface oxide film remarkably, a lower boric acid concentration or a higher lithium concentration produced an oxide film with a thicker surface. It was considered that the lower boric acid concentration and higher lithium hydroxide concentration caused a higher magnetite solubility at the surface of the material and that the higher magnetite solubility caused a higher iron concentration gradient, which promoted iron dissolution from the material and the formation of a thicker oxide film. It was found that the thicker oxide film caused a higher IGSCC susceptibility and that the corrosion was the dominant factor of the IGSCC mechanism. No significant change was found in the morphologies of crack tip oxide in different bulk water chemistry systems, thus producing CT specimens with similar crack growth rates. (author)

  14. Boric oxide or boric acid sintering aid for sintering ceramics

    International Nuclear Information System (INIS)

    Lawler, H.A.

    1979-01-01

    The invention described relates to the use of liquid sintering aid in processes involving sintering of ceramic materials to produce dense, hard articles having industrial uses. Although the invention is specifically discussed in regard to compositions containing silicon carbide as the ceramic material, other sinterable carbides, for example, titanium carbide, may be utilized as the ceramic material. A liquid sintering aid for densifying ceramic material is selected from solutions of H 3 BO 3 , B 2 O 3 and mixtures of these solutions. In sintering ceramic articles, e.g. silicon carbide, a shaped green body is formed from a particulate ceramic material and a resin binder, and the green body is baked at a temperature of 500 to 1000 0 C to form a porous body. The liquid sintering aid of B 2 O 3 and/or H 3 BO 3 is then dispersed through the porous body and the treated body is sintered at a temperature of 1900 to 2200 0 C to produce the sintered ceramic article. (U.K.)

  15. Enraizamento de estacas de Ginkgo biloba tratadas com ácido indolbutírico e ácido bórico Rooting of Ginkgo biloba cuttings treated with indolbutyric and boric acids

    Directory of Open Access Journals (Sweden)

    Janice Valmorbida

    2008-04-01

    Full Text Available Objetivou-se neste trabalho estudar o efeito do ácido indolbutírico (AIB e do ácido bórico (B no enraizamento de estacas de Ginkgo biloba. Em estacas com duas folhas, medindo 15 cm de comprimento foram provocadas duas lesões na base de aproximadamente 2 cm, expondo o câmbio e procedeu-se à imersão por 10 segundos no tratamento correspondente, AIB (0, 1000, 2000 e 3000 mg L-1 na ausência ou presença de B (0 e 150 mg L-1. Em seguida foram colocadas para enraizar em bandejas de polipropileno contendo areia lavada. O delineamento foi em blocos casualizados num fatorial 4X2, com seis repetições. Foram avaliadas porcentagem de estacas enraizadas, estacas não enraizadas e mortas, diâmetro e comprimento das raízes, aos 70 dias do tratamento. Os dados foram submetidos à análise de variância sendo previamente testados para normalidade pelo Teste de Shapiro-Wilk. As médias foram comparadas pelo Teste de Tukey. Os tratamentos com 2000 mg L-1 de AIB foram superiores à ausência de AIB (80,55% vs. 55,56%, respectivamente, não diferindo dos demais tratamentos. A utilização de B não afetou a taxa de enraizamento, de estacas não enraizadas e mortas, não havendo interação entre a concentração de AIB e a utilização ou não de B. O diâmetro e o comprimento das raízes não foram afetados pela utilização de AIB e B.The aim of the work was to study the effect of indolbutyric (IBA and boric (B acids to root Ginkgo biloba cuttings. At the base of cuttings, with two leaves and 15 cm of length, were made two lesions with 2 cm to expose the cambium. Cuttings were treated for a period of 10 seconds with four concentrations of IBA (0, 1000, 2000 and 3000 mg L-1 combined with two concentration of B (0 and 150 mg L-1. After that, cuttings were taken in polypropylene trays filled with washed sand. The experimental design was of randomized blocks in the factorial arrangement (4x2, with six replications. After 70 days, evaluations were done

  16. Cementation of wastes with boric acid

    International Nuclear Information System (INIS)

    Tello, Cledola C.O.; Haucz, Maria Judite A.; Alves, Lilian J.L.; Oliveira, Arno H.

    2000-01-01

    In nuclear power plants (PWR) are generated wastes, such as concentrate, which comes from the evaporation of liquid radioactive wastes, and spent resins. Both have boron in their composition. The cementation process is one of the options to solidify these wastes, but the boron has a negative effect on the setting of the cement mixture. In this paper are presented the experiments that are being carried out in order to overcome this problem and also to improve the efficiency of the process. Simulated wastes were cemented using additives (clays, admixtures etc.). In the process and product is being evaluated the effect of the amount, type and addition order of the materials. The mixtures were selected in accordance with their workability and incorporated waste. The solidified products are monolithic without free water with a good mechanical resistance. (author)

  17. Enraizamento de estacas do porta-enxerto de videira 'vr 043-43' submetidas a estratificação, ácido indolbutírico e ácido bórico Rooting cuttings of rootstocks of grape vine 'vr 043-43' submitted to the stratification, indolebutyric acid and boric acid

    Directory of Open Access Journals (Sweden)

    Ariane Busch Salibe

    2010-01-01

    Full Text Available O presente trabalho teve como objetivo estudar o enraizamento de estacas de porta-enxerto 'VR 043-43' (V. vinifera x V. rotundifolia, testando diferentes concentrações de ácido indolbutírico (0, 1.000, 2.000 e 3.000 mg L-1, ácido bórico (0 e 150 µg L-1 e a técnica de estratificação a 4 ºC por 48 horas em câmara refrigerada. Utilizou-se o delineamento experimental em blocos inteiramente casualizados, em esquema fatorial 4 x 2 x 2, com cinco repetições e cada parcela representada por oito estacas. Após 120 dias do plantio das estacas, os seguintes dados biométricos foram mensurados: porcentagem de estacas enraizadas, comprimento médio radicial, massa da parte aérea, massa do sistema radicial e número de raízes. Verificou-se que a estratificação das estacas e a utilização de ácido bórico não afetaram o enraizamento do porta-enxerto 'VR 043-43'. No que se refere ao tratamento com ácido indolbutírico, a concentração de 3.000 mg L-1 favoreceu sensivelmente o desenvolvimento do sistema radicial das estacas do porta-enxerto.The present work had as objective to study the rooting of rootstocks 'VR 043-43' (V. vinifera x V. rotundifolia, testing different concentrations of indolebutyric acid (0, 1.000, 2.000 and 3.000 mg L-1, boric acid (0 and 150 μg L-1 and the technique of the stratification at 4 °C for 48 hours in cooled chamber. We used a randomized complete block design, in factorial scheme 4 x 2 x 2, with five repetitions and each parcel represented for eight cuttings. After 120 days of planting the cuttings, the following biometric data were measured: percentage of rooting cuttings, average length root, mass of the aerial part, mass of the radicial system and number of roots. It was verified that the stratification of the cuttings and the use of boric acid did not affect the rooting of the rootstocks 'VR 043-43'. With regard the treatment with indolebutyric acid, the concentration of 3.000 mg L-1 significantly

  18. Efeitos da aplicação de reguladores vegetais e do ácido bórico, em estacas de lichieira (Litchi chinensis Sonn. Effects of growth regulators and boric acid on lychee (Litchi chinensis Sonn. cuttings

    Directory of Open Access Journals (Sweden)

    S. Leonel

    1993-05-01

    Full Text Available Estudaram-se as interações entre os ácidos indol-butírico, alfa-naftaleno-acético e bórico no desenvolvimento de calos e na sobrevivência das estacas de lichieira (Litchi chinensis Sonn.. As estacas apresentavam 25 cm de comprimento e 4 folhas cortadas pela metade, sendo retiradas em duas épocas diferentes (janeiro e abril e colocadas para enraizar em bandejas de isopor, tendo como substrato vermiculita e em condições de câmara de nebulização. Foi feita imersão de 2,5 cm da base das estacas, em soluções aquosas por l minuto. Os tratamentos utilizados corresponderam a 5.000 e 2.000 ppm de IBA; 3.000 e 1.500 ppra de NAA; 150 microgramas/ml de H3BO3; IBA 5.000 e 2.000 ppm + H3BO(3150 microgramas/ml; NAA 3.000 e 1.500 ppm + H3BO3 150 microgramas/ml e H2O. Avaliou-se a formação de calos e a sobrevivência das estacas após 120 dias do plantio. Através dos resultados obtidos, foi possível concluir que dos tratamentos utilizados, nenhum foi efetivo na formação de raízes, havendo somente a formação de calos. A melhor época para a retirada de estacas correspondeu ao mês de abril.Interactions between indolebutyric, naphtalen acetic and boric acids were studied on "callus" development and survival in lychee (Litchi chinensis Sonn. cuttings. The cuttings were twenty five cm long with four leaves cut in half and taken in two different periods (January and April Styrofoam trays, with vermiculite as substratum kept under intermittent mist were used as rooting media. Cuttings were imersed up to 2.5 cm from the base in water solutions, for one minute. The treatments were: 5,000 and 2,000 ppm of IBA; 3,000 and 1,500 ppm of NAA; 150 micrograms/ml H3BO3; IBA 5,000 and 2,000 ppm plus H3BO3 150 micrograms/ml; NAA 3,000 and 1,500 ppm plus boron 150 micrograms/ml and II2O. "Callus" formation and cutting survival were evaluated 120 days after planting. It was concluded that no treatments were effective on root formation, however, "callus

  19. Viabilidade in vitro de grãos de pólen de bananeira sob diferentes concentrações de ácido bórico e sacarose In vitro viability of banana pollen grain under different concentrations of boric acid and sucrose

    Directory of Open Access Journals (Sweden)

    Ronaldo Viana dos Reis

    2011-06-01

    Full Text Available Neste trabalho, objetivou-se avaliar a germinação do grão de pólen e o comprimento do tubo polínico das bananeiras diplóides M53, 8987-01 e 9197-03, Calcutá, Lidi e 86B79-12. O delineamento utilizado foi inteiramente casualizado com cinco doses de sacarose (0, 5, 10, 15, 20% e seis concentrações de ácido bórico (0, 100, 200, 300, 400 e 500 Mg L-1 com quatro repetições. Foram utilizados grãos de pólen retirados da inflorescência masculina dos diplóides Musa acuminata (AA. O pólen foi distribuído em placas de Petri, contendo o seguinte meio de cultura: 1,27 mM de Ca(NO32.2H2O, 0,87 mM de MgSO4.7H2O, 0,99 mM de KNO3, 0,7% de ágar com pH ajustado para 7,0, variando as concentrações de sacarose e de ácido bórico. As avaliações foram realizadas 24 horas após a distribuição do pólen no meio de cultura. O meio de cultura padrão para germinação de grãos de pólen suplementado com 15% de sacarose proporcionou uma maior percentagem de germinação para os diplóides de bananeira avaliados. A concentração de ácido bórico adicionado ao meio de cultura para a germinação de grãos de pólen de bananeira diplóide é dependente do genótipo.The objective of this work was to evaluate the germination of pollen grain and pollen tube length of banana diploids (M53, 8987-01 e 9197-03, Calcutta, Lidi and 86B79-12. Five concentrations of sucrose (0, 5, 10, 15 and 20% and six concentrations of boric acid (0, 100, 200, 300, 400 and 500 mg L-1 were used, in a completely randomized experimental design, with four replicates. The pollen was distributed in Petri dishes containing the following culture medium: 1.27 mM Ca(NO32.2H2O, 0.87 mM MgSO4.7H2O, 0.99 mM KNO3, and 0.7% agar; pH adjusted to 7.0, varying the sucrose and boric acid concentrations. The evaluations were performed 24 hours after the distribution of the pollen in the culture medium. The standard culture medium for germination of pollen grains with 15% sucrose provided the

  20. Boric Ester-Type Molten Salt via Dehydrocoupling Reaction

    Directory of Open Access Journals (Sweden)

    Noriyoshi Matsumi

    2014-11-01

    Full Text Available Novel boric ester-type molten salt was prepared using 1-(2-hydroxyethyl-3-methylimidazolium chloride as a key starting material. After an ion exchange reaction of 1-(2-hydroxyethyl-3-methylimidazolium chloride with lithium (bis-(trifluoromethanesulfonyl imide (LiNTf2, the resulting 1-(2-hydroxyethyl-3-methylimidazolium NTf2 was reacted with 9-borabicyclo[3.3.1]nonane (9-BBN to give the desired boric ester-type molten salt in a moderate yield. The structure of the boric ester-type molten salt was supported by 1H-, 13C-, 11B- and 19F-NMR spectra. In the presence of two different kinds of lithium salts, the matrices showed an ionic conductivity in the range of 1.1 × 10−4–1.6 × 10−5 S cm−1 at 51 °C. This was higher than other organoboron molten salts ever reported.

  1. Micropropagação de duas espécies frutíferas, em meio de cultura DSD1, modificado com fontes de boro e zinco Micropropagation of two fruit tree species on dsd1 culture medium modified with boric acid and zinc sulfate

    Directory of Open Access Journals (Sweden)

    Fabíola Villa

    2009-04-01

    H adjusted to 6.4 before the sterilization at 121ºC and 1 atm per 20 minutes. The treatments consisted of blackberry plants cv. Tupy, the grapevine rootstock 'Kobber' and concentrations of boric acid (0; 1.0; 2.0, and 4.0 mg L-1 and zinc sulfate (0; 1.0; 2.0, and 4.0 mg L-1, mixed in all possible combinations. Nodal segments of in vitro cultivated plants were excised and inoculated in tubes with 15 mL culture medium. After that, the tubes were transferred to a growth room at 27 ± 1ºC, irradiance of 35 mol.m-2.s-1 and photoperiod of 16 hours. The experiment was arranged in a completely randomized design, using four replications with 12 plants each. After 70 days of in vitro cultivation it was verified that the best results for the micropropagation of blackberry cv. Tupy (Rubus sp. were obtained in the absence of boric acid and zinc sulfate mixed in the DSD1culture medium. With 4.0 mg L-1 boric acid added to the culture medium higher number of leaves and length of roots of the grapevine rootstock 'Kobber' (Vitis sp. was observed.

  2. Crystallo-chemistry of boric anhydride and of anhydrous borates

    International Nuclear Information System (INIS)

    Bernardin, Jacques

    1968-01-01

    After an overview of various aspects related to the atomic structure of boron and of its three-bind and four-bind compounds, this report briefly presents the different forms of boric anhydride (in solid, liquid, glassy and gaseous state), presents and comments the structure of these different forms, and addresses the molten boric anhydride which is used as oxide solvent. The next part addresses the structure of anhydrous borates. It presents some generalities on their structure, and describes examples of known structures: dimers, trimers, polymers with a degree higher than three like calcium metaborate, caesium tri-borate, lithium tetraborate, or potassium pentaborate

  3. Effects on concrete from borated water and boric compounds cast into the concrete

    International Nuclear Information System (INIS)

    Fagerlund, Goeran

    2010-06-01

    A study has been made of the effects on concrete of its exposure to external water containing boric acid, and the effects on concrete of boric compounds cast into the concrete during its manufacture. According to information in literature boric acid is a weak Lewis acid that has no effect on concrete. Reaction between calcium hydroxide existing in concrete and boric acid might occur at the concrete surface. The reaction product formed (calcium-metaboritehexahydrate) has lower solubility than calcium hydroxide itself. Therefore, the reaction is reasonably harmless. Accelerated and non-accelerated test methods exist by which quantitative information on the effect of boric acid can be obtained. The test principles are described. Boron-containing compounds might be mixed into concrete in order to increase its resistance to neutron radiation. Pure boron minerals, as well as boron-containing residual materials from processing of natural boron minerals, might be used. Concrete might be affected with regard to the following properties: - Workability of the fresh concrete; - Stiffening and hardening of the concrete; - Strength (compression, tension); - Deformation (E-modulus, creep); - Durability (chemical, steel corrosion. Information in literature indicates that the hardening process might be severely affected also when rather small amounts of certain boron-containing materials are used. The effect seems to be small, or none, however, if materials with low solubility are used. The effect on workability seems to be marginal. Test methods exist by which it is practical possible to develop acceptable concrete recipes. The effects on mechanical properties are not well clarified by research. However, effects seem to be small when boron materials with low solubility are used. In one study, in which part of the cement was replaced by a boron containing colemanite waste, it was found that the E-modulus was very much reduced. The significance of this result is unclear. The

  4. Synthesis of trialkyloboron from boric oxide and organoaluminium compounds

    International Nuclear Information System (INIS)

    Synoradzki, L.; Boleslawski, M.; Pasynkiewicz, S.; Zawada, T.

    1981-01-01

    The reaction of organoaluminium compounds with boric oxide has been studied. The facility of forming trialkyloboron decreases corresponding to the sequence: RAlCl 2 >R 3 Al 2 Cl 3 >R 2 AlCl>R 3 Al. The best yields have been obtained at the temperature of the boiling point of the reaction mixture and at a vigorous mixing. The new method of simultaneous obtaining of trialkyloboron and alkylaluminium chloride having an industrial significance has been proposed. (author)

  5. fluconazole and boric acid for treatment of vaginal candidiasis

    African Journals Online (AJOL)

    2013-04-01

    Apr 1, 2013 ... M. K. Khameneie, Assistant Professor, Department of Obstetrics and Gynecology, Imam Reza hospital, Tehran - Iran,. N. Arianpour ..... candidiasis. Am Fam Physician. 2000;1, 61:3306-12. 12. Donders GG, Bellen G, Mendling W. Management of recurrent vulvo-vaginal candidosis as a chronic illness.

  6. Computer modeling of homogenization of boric acid in IRIS pressurizer

    International Nuclear Information System (INIS)

    Rives Sanz, Ronny; Montesinos Otero, Maria Elena; Gonzalez Mantecon, Javier

    2015-01-01

    Integral layout of nuclear reactor IRIS makes possible the elimination of the spray system; which is usually used to mitigate in-surge transient and help to boron homogenization. The study of transients with deficiencies in the boron homogenization in this technology is very important, because they can cause disturbances in the reactor power and insert a strong reactivity in the core. The aim of the present research is to model the IRIS pressurizer using the CFX code searching for designs alternatives that guaranteed its intrinsic security, focused on the phenomena before mentioned. A symmetric tri dimensional model equivalent to 1/8 of the total geometry was adopted to reduce mesh size and minimize processing time. The relationships are programmed and incorporated into the code. This paper discusses the model developed and the behavior of the system for representative transients sequences. The results of the analyzed IRIS transients could be applied to the design of the pressurizer internal structures and components. (Author)

  7. Toxicological studies on the Use of acid applied or combined with gamma radiation for controlling the mediterranean fruit fly Ceratitis Capitata Wied

    International Nuclear Information System (INIS)

    Fadel, A.M.; Othman, K.S.A.

    1997-01-01

    Biological studies were conducted to determine the effect of boric acid applied alone to different stages of ceratitis capitata or combined with gamma radiation of the produced treated pupae (9 days old). At a concentration range of 200-2000 ppm of boric acid per gm larval diet, larval and pupal durations were insignificantly affected. Pupation significantly decreased with increasing concentration, and adult emergence significantly increased at higher concentrations. Lc50 value of boric acid applied to the larval diet was 250 ppm. Applying boric acid as a powder mixed with pupal medium, the Lc50 was 96 mg/gm sand. Male and emergence significantly decreased. Significant mortality was obtained in adults of C capitata after applying boric acid as a thin film on the inner surface of the experimental cages where the adults were kept or when mixed with their food or as powder on the cage bottom. Applying boric acid to larval diet and gamma radiation to the produced pupae (9 days old) insignificantly affected larval and durations, percent pupation, adult emergence or adult survival. In cross-mating experiments, egg hatch ability was significantly reduced in the combination treatments of boric acid (500, 1000 ppm) and gamma radiation (90 Gy). On the other hand gamma radiation combined with boric acid treatments significantly increased male mating competitiveness at the concentration of 1000 ppm of boric acid followed by gamma irradiation (90 Gy). 2 figs., 5 tabs

  8. Efeito da época de estaquia, fitorreguladores e ácido bórico no enraizamento de estacas de porta-enxertos de videira Effect of pruning time, growth regulators and boric acid on rooting of grape rootstock cuttings

    Directory of Open Access Journals (Sweden)

    S. Leonel

    1993-05-01

    Full Text Available Estudaram-se as interações entre os ácidos indol-butírico, alfa-naftaleno-acético e bórico no desenvolvimento de raízes em estacas de porta-enxertos de videira (Vitis vinifera L.. As estacas tinham aproximadamente 25 cm de comprimento e, necessariamente, 2 gemas, sendo obtidas em três épocas distintas (janeiro, abril e julho e colocadas para enraizar em bandejas de isopor, tendo vermiculita como substrato, e mantidas sob nebulização. O tratamento constou da imersão de 2,5 cm da base das estacas em soluções, por um tempo de imersão de 1 minuto. Os tratamentos utilizados corresponderam a: 1 .000; 2.000 e 5.000 ppm de IBA; 1.500 e 3.000 ppm de NAA; 150 microgramas/ml de H3BO3; IBA 1.000; 2.000 e 5.000 + H3BO3 150 microgramas/ml e H2O. Avaliaram-se a porcentagem de enraizamento, o número médio de raízes formadas por estaca e o comprimento médio das raízes (mm aos 90 dias após a instalação, no mês de julho. O IBA 2.000 ppm propiciou o enraizamento em 88,87% das estacas, contudo não diferiu estatisticamente da testemunha (H2O-61,10%. A melhor época de coleta de estaca para o enraizamento foi o mês de julho (inverno.The effects of indolebutyric, naphtalen acetic and boric acids were studied on rooting of grape rootstock cuttings. The cuttings were 25 cm long with two buds and were taken in three different times (January, April and July. Rooting was carried out in styrofoam trays with vermiculite as substratum and under intermittent mist. Cuttings were imersed up to 2.5 cm from the base in solutions for one minute. The treatments were: 1,000; 2,000 and 5,000 ppm of IBA; 1,500 and 3,000 ppm of NAA; 150 micrograms/ml H3BO3; IBA 1,000; 2,000 and 5,000 ppm plus H3BO(3150 niicrograins/ml and H2O. Rooting percentage, average number of roots per cutting and average length of roots (mm were evaluated 90 days after planting, in July. IBA at 2,000 ppm was the best treatment with 88.8% of rooted cuttings. The best time for rooting was

  9. Determination of organic acids evolution during apple cider fermentation using an improved HPLC analysis method

    NARCIS (Netherlands)

    Zhang, H.; Zhou, F.; Ji, B.; Nout, M.J.R.; Fang, Q.; Zhang, Z.

    2008-01-01

    An efficient method for analyzing ten organic acids in food, namely citric, pyruvic, malic, lactic, succinic, formic, acetic, adipic, propionic and butyric acids, using HPLC was developed. Boric acid was added into the mobile phase to separate lactic and succinic acids, and a post-column buffer

  10. Electrodeposited Fe-Co films prepared from a citric-acid-based plating bath

    OpenAIRE

    Yanai, Takeshi; Uto, H.; Shimokawa, Takaya; Nakano, Masaki; Fukunaga, Hirotoshi; Suzuki, K.

    2013-01-01

    Electrodeposited Fe-Co films are commonly prepared in a boric-acid-based bath. In this research, we applied citric acid instead of boric acid for the plating of Fe-Co films because boron in the waste bath is restricted by environmental-protection regulations in Japan. We evaluated the effect of citric acid on the magnetic and structural properties of the films. The saturation magnetization of the Fe-Co films slightly increased while the Fe content in the Fe-Co films decreased with increasing ...

  11. A Study on Load Following Operation Strategy to Minimize Boric-acid Adjustment

    International Nuclear Information System (INIS)

    Yoo, Jae Woon

    1997-02-01

    Applicability of the MSHIM control strategy, which has been developed by Westinghouse and characterized by elimination of the adjustment to the boron concentration during load maneuvering, to 1300MWe KNGR Cycle-1 is examined by simulation based on one-dimensional transient analyses code, ONED94, under the conditions of relatively large xenon worth and high amplitude of xenon oscillation. CASMO-3/MASTER code system is used to generate the ONED94 model. A processing code, which is referred to as MAS2ONED, is also developed to transform the MASTER calculation results to ONED94 cross section library. The three types of power maneuvering, daily maneuvering, extended weekend load follow, and spinning reserve capacity are simulated to evaluate the capability of the selected load follow technology, by using ONED94 code. By showing that the calculated total peaking factor is maintained below safety limit, it is proved that load follow operation without boron adjustment is feasible with simple control rod motion only. It is expected that the results of this study, such as control rod parameters could give a contribution to the development of load following technology in our country. The developed process code could be utilized in the another simulation of power maneuver in the future

  12. Mixed ligand complex formation of Fe with boric acid and typical N ...

    Indian Academy of Sciences (India)

    Unknown

    diethylenetriamine and triethylenetetramine (L) in different molar ratios provides ... the complexes at 25 ± 0⋅1°C in aqueous solution at a fixed ionic strength,. I = 0⋅1 mol ... acid–base, ion exchange and complexometric titrations5. ... concentrations of H+ ion corresponding to the pH-meter readings were obtained by the.

  13. The role of boric acid in the synthesis of Eni Carbon Silicates.

    Science.gov (United States)

    Zanardi, Stefano; Bellussi, Giuseppe; Parker, Wallace O'Neil; Montanari, Erica; Bellettato, Michela; Cruciani, Giuseppe; Carati, Angela; Guidetti, Stefania; Rizzo, Caterina; Millini, Roberto

    2014-07-21

    The influence of H3BO3 on the crystallization of hybrid organic-inorganic aluminosilicates denoted as Eni Carbon Silicates (ECS's) was investigated. Syntheses were carried out at 100 °C under different experimental conditions, using bridged silsesquioxanes of general formula (EtO)3Si-R-Si(OEt)3 (R = -C6H4- (BTEB), -C10H6- (BTEN) and -C6H4-C6H4- (BTEBP)), in the presence of equimolar concentrations of NaAlO2 and H3BO3. The study, involving the synthesis of three different but structurally related phases (ECS-14 from BTEB, ECS-13 here described for the first time from BTEN, and ECS-5 from BTEBP), confirmed a catalytic role for H3BO3 which in general increased the crystallization rate and improved the product quality in terms of amount of crystallized phase (crystallinity), size of the crystallites and phase purity, while it was weakly incorporated in trace amounts in the framework of ECS's.

  14. Cementation of wastes with boric acid; Cimentacao de rejeitos contendo acido borico

    Energy Technology Data Exchange (ETDEWEB)

    Tello, Cledola C.O.; Haucz, Maria Judite A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Alves, Lilian J.L.; Oliveira, Arno H. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2000-07-01

    In nuclear power plants (PWR) are generated wastes, such as concentrate, which comes from the evaporation of liquid radioactive wastes, and spent resins. Both have boron in their composition. The cementation process is one of the options to solidify these wastes, but the boron has a negative effect on the setting of the cement mixture. In this paper are presented the experiments that are being carried out in order to overcome this problem and also to improve the efficiency of the process. Simulated wastes were cemented using additives (clays, admixtures etc.). In the process and product is being evaluated the effect of the amount, type and addition order of the materials. The mixtures were selected in accordance with their workability and incorporated waste. The solidified products are monolithic without free water with a good mechanical resistance. (author)

  15. Effect of boric acid sintering aid on densification of barium ferrite

    Indian Academy of Sciences (India)

    Unknown

    Physical properties like density and porosity have been studied for all compositions. The phase identification and microstructural investigation on the fractured surface have been carried out to understand the effect of sintering aid on the densification characteristics. Keywords. Barium ferrite; sintering aid; densification. 1.

  16. Boric acid as a mild and efficient catalyst for one-pot synthesis of 1 ...

    Indian Academy of Sciences (India)

    4, July 2012, pp. 927–931. c ..... 35 45. 4. Kantevari S, Vuppalapati S V N and Nagarapu L 2007. Catal. ... Chem. Lett. 18 788. 12. Nandi G C, Samai S, Kumar R and Singh M S 2009 ... Wang M, Song Z G and Liang Y 2012 Synthetic Com- mun.

  17. Equilibrium study on the reactions of boric acid with some cis-diaqua ...

    Indian Academy of Sciences (India)

    Unknown

    borate complexes ... of this group of ligands with trivalent metal ions.1,4 The present paper describes the results of a systematic equilibrium ..... Harned H S and Owen B B 1958 Physical chemistry of electrolytic solution (New York: Reinhold). 11.

  18. Boron removal from aqueous solutions by activated carbon impregnated with salicylic acid

    International Nuclear Information System (INIS)

    Celik, Z. Ceylan; Can, B.Z.; Kocakerim, M. Muhtar

    2008-01-01

    In this study, the removal of boric acid from aqueous solution by activated carbon impregnated with salicylic acid was studied in batch system. pH, adsorbent amount, initial boron concentration, temperature, shaking rate and salicylic acid film thickness were chosen as parameters. Boron removal efficiencies increased with increasing adsorbent amount, temperature and pH, decreasing initial boron concentration. As thickness of salicylic acid film on activated carbon becomes thin up to 0.088 nm, the efficiency increased, and then, the efficiency decreased with becoming thinner than 0.088 nm of salicylic acid film. Shaking rate was no effect on removal efficiency. In result, it was determined that the use of salicylic acid as an impregnant for activated carbon led to the increase of the amount of boron adsorbed. A lactone ring, being the most appropriate conformation, forms between boric acid and -COOH and -OH groups of salicylic acid

  19. Boron removal from aqueous solutions by activated carbon impregnated with salicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Celik, Z. Ceylan [Department of Environmental Engineering, Atatuerk University, Faculty of Engineering, Erzurum (Turkey)], E-mail: zcelik@atauni.edu.tr; Can, B.Z. [Department of Environmental Engineering, Atatuerk University, Faculty of Engineering, Erzurum (Turkey); Kocakerim, M. Muhtar [Department of Chemical Engineering, Atatuerk University, Faculty of Engineering, 25240 Erzurum (Turkey)

    2008-03-21

    In this study, the removal of boric acid from aqueous solution by activated carbon impregnated with salicylic acid was studied in batch system. pH, adsorbent amount, initial boron concentration, temperature, shaking rate and salicylic acid film thickness were chosen as parameters. Boron removal efficiencies increased with increasing adsorbent amount, temperature and pH, decreasing initial boron concentration. As thickness of salicylic acid film on activated carbon becomes thin up to 0.088 nm, the efficiency increased, and then, the efficiency decreased with becoming thinner than 0.088 nm of salicylic acid film. Shaking rate was no effect on removal efficiency. In result, it was determined that the use of salicylic acid as an impregnant for activated carbon led to the increase of the amount of boron adsorbed. A lactone ring, being the most appropriate conformation, forms between boric acid and -COOH and -OH groups of salicylic acid.

  20. 3.6. The kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore. The experimental data of kinetics of extraction of boron oxide from danburite at sulfuric acid decomposition were obtained at 20-90 deg C temperature range and process duration 15-90 minutes. The flowsheet of obtaining of boric acid from borosilicate ores of Ak-Arkhar Deposit by sulfuric acid method was proposed.

  1. The nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    Kurbonov, A.S.; Mamatov, E.D.; Suleymani, M.; Borudzherdi, A.; Mirsaidov, U.M.

    2011-01-01

    Present article is devoted to nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit of Tajikistan. The obtaining of boric acid from pre backed danburite concentrate by decomposition of nitric acid was studied. The chemical composition of danburite concentrate was determined. The laboratory study of danburite leaching by nitric acid was conducted. The influence of temperature, process duration, nitric acid concentration on nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit was studied as well. The optimal conditions of nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit, including temperature, process duration, nitric acid concentration and particle size were proposed.

  2. THE KINETICS OF SAPONIFICATION OF IODOACETIC ACID BY SODIUM HYDROXIDE AND BY CERTAIN ALKALINE BUFFER SOLUTIONS.

    Science.gov (United States)

    Brdicka, R

    1936-07-20

    1. The rate of the saponification of iodoacetic acid in sodium hydroxide and alkaline buffer solutions yielding glycollic acid was measured by means of Heyrovský's polarographic method. 2. From the bimolecular velocity constants, increasing with the ionic strength of the solution, the Brönsted factor, F, which characterizes the primary salt effect, was calculated. 3. In the borate buffer solutions the monomolecular constants of the saponification were determined which, at values above the pH of neutralization of boric acid, show a proportionality to the concentration of hydroxyl anions. Below the pH of neutralization of boric acid, they are proportional to the concentration of borate anions.

  3. Immobilized laccase mediated dye decolorization and transformation pathway of azo dye acid red 27

    OpenAIRE

    Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

    2015-01-01

    Background Laccases have good potential as bioremediating agents and can be used continuously in the immobilized form like many other enzymes. Methods In the present study, laccase from Cyathus bulleri was immobilized by entrapment in Poly Vinyl Alcohol (PVA) beads cross-linked with either nitrate or boric acid. Immobilized laccase was used for dye decolorization in both batch and continuous mode employing a packed bed column. The products of degradation of dye Acid Red 27 were identified by ...

  4. 4.2. The kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit. The dependence of nitric acid decomposition of calcined boric raw material for extraction of boron oxide on temperature (20-100 deg C) and process duration (15-60 minutes) was defined. It was defined that at temperature increasing the extraction rate of boron oxide increases from 20.8 to 78.6%.

  5. Direct solid surface fluorescence spectroscopy of standard chemicals and humic acid in ternary system.

    Science.gov (United States)

    Mounier, S; Nicolodelli, G; Redon, R; Milori, D M B P

    2017-04-15

    The front face fluorescence spectroscopy is often used to quantify chemicals in well-known matrices as it is a rapid and powerful technique, with no sample preparation. However it was not used to investigate extracted organic matter like humic substances. This work aims to fully investigate for the first time front face fluorescence spectroscopy response of a ternary system including boric acid, tryptophan and humic substances, and two binaries system containing quinine sulfate or humic substance in boric acid. Pure chemicals, boric acid, tryptophan, quinine sulfate and humic acid were mixed together in solid pellet at different contents from 0 to 100% in mass. The measurement of excitation emission matrix of fluorescence (3D fluorescence) and laser induced fluorescence were then done in the front face mode. Fluorescence matrices were decomposed using the CP/PARAFAC tools after scattering treatments. Results show that for 3D fluorescence there is no specific component for tryptophan and quinine sulfate, and that humic substances lead to a strong extinction effect for mixture containing quinine sulfate. Laser induced fluorescence gives a very good but non-specific related response for both quinine sulfate and tryptophan. No humic substances fluorescence response was found, but extinction effect is observed as for 3D fluorescence. This effect is stronger for quinine sulfate than for tryptophan. These responses were modeled using a simple absorbance versus emission model. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Introduction - Acid decomposition of borosilicate ores

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    The complex processing of mineral raw materials is an effective way for the extraction of valuable components. One of these raw materials are borosilicate ores from which the boric acid, aluminium and iron salts and building materials can be obtained. In the Institute of Chemistry of the Academy of Sciences of the Republic of Tajikistan the flowsheets of the processing of borosilicate raw materials by acid and chloric methods were elaborated. The acid methods of decomposition of borosilicate ores of Ak-Arkhar Deposit were considered in present monograph. The carried out researches on elaboration of physicochemical aspects and technological acid methods allowed to define the optimal ways of extraction of valuable products from borosilicate raw materials of Tajikistan.

  7. Bituminization of simulated PWR type reactor wastes, boric evaporator bottons and ion exchange resins, carried out in CNEN/SP using commercial bitumen available in the Brazilian market

    International Nuclear Information System (INIS)

    Grosche Filho, C.E.; Chandra, U.

    1986-01-01

    The first results of the study of bituminization of simulated PWR wastes, boric evaporator bottons and spent ion-exclange resins (OH - , H + ) and incinerated ash-wates are presented and discussed. The study consisted of characterization of the commercial bitumen, locally available and bitumen wastes products of varying whight compositions. The characterization was carried out using standard analysis methods of ABNT and ASTM, and included measurement of, penetration, softening point and flash point. In addition, the bitumen samples were analized for their resin and asphaltene contents. For leaching studies, wastes products of bitumen and resin loaded with 134 Cs were utilized. The method used was according to the ISO norms. The simulation of the industrial process was carried out using an extruder-evaporator typically used in the plastic industries offered by Industria de Maquinas Miotto Ltda., Sao Bernardo do Campo - SP. (Author) [pt

  8. Acid-permanganate oxidation of potassium tetraphenylboron

    International Nuclear Information System (INIS)

    Smith, J.R.

    1993-02-01

    Scoping experiments have been performed which show that potassium tetraphenylboron (KTPB) is rapidly oxidized by permanganate in acidic solutions at room temperature. The main Products are CO 2 , highly oxidized organic compounds related to tartaric and tartronic acids, boric acid, and potassium phosphate (when phosphoric acid is used as the source of acid). One liter of 0.6M NaMnO 4 /2.5M H 3 PO 4 solution will destroy up to 8 grams of KTPB. The residual benzene concentration has been measured to be less than the RCRA limit of 0.5 ppm. Approximately 30% of the organic material is released as CO 2 (trace CO) and 0.16% as benzene vapor. The reaction is well behaved, no foaming or spattering. Tests were performed from .15M to near 1M permanganate. The phosphoric acid concentration was maintained at a concentration at least three times that of the permanganate since an excess of acid was desired and this is the ratio that these two reagents are consumed in the oxidation

  9. Effect of time period after boric acid injection on {sup 10}B absorption in different regions of adult male rat's brain

    Energy Technology Data Exchange (ETDEWEB)

    Baghban Khojasteh, Nasrin, E-mail: khojasteh.nasrin@gmail.com [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Poonak Sq. PO Box 14515-775, Tehran (Iran, Islamic Republic of); Pazirandeh, Ali [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Poonak Sq. PO Box 14515-775, Tehran (Iran, Islamic Republic of); Jameie, Behnam [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Poonak Sq. PO Box 14515-775, Tehran (Iran, Islamic Republic of); Laboratory of Basic Science and Neuroscience, Basic Science Dept, Faculty of Allied Medicine, Cellular and Molecular Research Center, Tehran University of Medical Science, Pardis-e-Hemmat,Tehran (Iran, Islamic Republic of); Goodarzi, Samereh [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Poonak Sq. PO Box 14515-775, Tehran (Iran, Islamic Republic of)

    2012-06-15

    Distribution of {sup 10}B in different regions of rat normal brain was studied. Two groups were chosen as control and trial. Trial group received 2 ml of neutral boron compound. 2, 4 and 6 h after the injection brain removed, coronal sections of forebrain, midbrain and hindbrain were sandwiched between two pieces of polycarbonate. Autoradiography plots of {sup 10}B distribution showed significant differences in three regions with the highest {sup 10}B concentration in the forebrain during 4 h after injection. - Highlights: Black-Right-Pointing-Pointer Normal tissue tolerance is very important in BNCT. Black-Right-Pointing-Pointer This study has been done to determine {sup 10}B distribution in three anatomical regions of rat normal brain. Black-Right-Pointing-Pointer These specific regions of brain have not been studied in previous BNCT projects. Black-Right-Pointing-Pointer We found significant differences in {sup 10}B distribution between these three regions. Black-Right-Pointing-Pointer In different time periods after neutral boron compound injection, there has been a significant difference in boron absorption.

  10. Separation of glycols from dilute aqueous solutions via complexation with boronic acids

    Energy Technology Data Exchange (ETDEWEB)

    Randel, L.A.; King, C.J.

    1991-07-01

    This work examines methods of separating low molecular weight glycols from dilute aqueous solution. Extraction into conventional solvents is generally not economical, since, in the literature reviewed, distribution ratios for the two- to four-carbon glycols are all less than one. Distribution ratios can be increased, however, by incorporating into the organic phase an extracting agent that will complex with the solute of interest. The extracting agent investigated in this work is 3-nitrophenylboronic acid (NPBA). NPBA, a boric acid derivative, reversibly complexes with many glycols. The literature on complexation of borate and related compounds with glycols, including mechanistic data, measurement techniques, and applications to separation processes, provides information valuable for designing experiments with NPBA and is reviewed herein. 88 refs., 15 figs., 24 tabs.

  11. Rapid determination of the equivalence volume in potentiometric acid-base titrations to a preset pH-I Theory and applications.

    Science.gov (United States)

    Ivaska, A

    1974-06-01

    A new approach to shorten the time needed for an acid-base titration has been made. The method developed is based on the equation for acid-base titrations derived by Ingman and Still. The equation is transformed into such a form that only one titration point is needed to calculate the equivalence volume when the titration is carried out to a preset pH which can be chosen according to the experimental conditions. The method is used for titration of acetic acid, log K(H)(HA) = 4.65, hydroxylammonium ion, log K(H)(HA) approximately 6.2, and boric acid, log K(H)(HA) approximately 9.1, with an error of 0.1-0.5%. In titration of hydrogen ascorbate ion, log K(H)(HA) approximately 11.3, the error obtained was about 0.3-2%.

  12. An Optical Test Strip for the Detection of Benzoic Acid in Food

    Directory of Open Access Journals (Sweden)

    Fatimah Abu Bakar

    2011-07-01

    Full Text Available Fabrication of a test strip for detection of benzoic acid was successfully implemented by immobilizing tyrosinase, phenol and 3-methyl-2-benzothiazolinone hydrazone (MBTH onto filter paper using polystyrene as polymeric support. The sensing scheme was based on the decreasing intensity of the maroon colour of the test strip when introduced into benzoic acid solution. The test strip was characterized using optical fiber reflectance and has maximum reflectance at 375 nm. It has shown a highly reproducible measurement of benzoic acid with a calculated RSD of 0.47% (n = 10. The detection was optimized at pH 7. A linear response of the biosensor was obtained in 100 to 700 ppm of benzoic acid with a detection limit (LOD of 73.6 ppm. At 1:1 ratio of benzoic acid to interfering substances, the main interfering substance is boric acid. The kinetic analyses show that, the inhibition of benzoic is competitive inhibitor and the inhibition constant (Ki is 52.9 ppm. The activity of immobilized tyrosinase, phenol, and MBTH in the test strip was fairly sustained during 20 days when stored at 3 °C. The developed test strip was used for detection of benzoic acid in food samples and was observed to have comparable results to the HPLC method, hence the developed test strip can be used as an alternative to HPLC in detecting benzoic acid in food products.

  13. Aspartic acid

    Science.gov (United States)

    ... we eat. Aspartic acid is also called asparaginic acid. Aspartic acid helps every cell in the body work. It ... release Normal nervous system function Plant sources of aspartic acid include: avocado, asparagus, and molasses. Animal sources of ...

  14. Acid Rain

    Science.gov (United States)

    Bricker, Owen P.; Rice, Karen C.

    1995-01-01

    Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

  15. Deboration in nuclear stations of the PWR type

    International Nuclear Information System (INIS)

    1978-01-01

    Reactivity control in nuclear power stations of the PWR type is realised with boric acid. A method to concentrate boric acid without an evaporator has been studied. A flow-sheet with reverse osmosis is proposed. (author)

  16. Amino acids

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  17. Valproic Acid

    Science.gov (United States)

    ... acid is in a class of medications called anticonvulsants. It works by increasing the amount of a ... older (about 1 in 500 people) who took anticonvulsants such as valproic acid to treat various conditions ...

  18. Ascorbic Acid

    Science.gov (United States)

    Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C in ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops to ...

  19. Aminocaproic Acid

    Science.gov (United States)

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  20. Ethacrynic Acid

    Science.gov (United States)

    Ethacrynic acid, a 'water pill,' is used to treat swelling and fluid retention caused by various medical problems. It ... Ethacrynic acid comes as a tablet to take by mouth. It is usually taken once or twice a day ...

  1. Un nuevo Método para Mejorar el Proceso de Producción de Acido Bórico A New Method to Improve the Production Process of Boric Acid

    OpenAIRE

    Orlando J Domínguez; Emilio M Serrano; Jorge E Flores; Raquel L Michel

    2011-01-01

    En este trabajo se propone una modificación al proceso tradicional para obtener ácido bórico, con el agregado fraccionado del ácido lixiviante, para lograr un producto altamente soluble, como el pentaborato de sodio. Con esto se consigue la disolución del mineral en frío con menor cantidad de reactivo lixiviante, ahorrando así energía. Al líquido clarificado se le disminuye el pH logrando así la precipitación del ácido bórico. La ganga se agota con diferentes etapas de precipitación y filtrac...

  2. BORIC-ACID MEDIATED PREPARATION OF MESOCYCLIC THIOCROWN ETHERS CONTAINING XYLYLENE UNITS - MOLECULAR-STRUCTURES OF 3,8-DIBENZO-1,6-DITHIACYCLODECANE AND 2,5,8-TRITHIA-(9)-P-BENZENOPHANE

    NARCIS (Netherlands)

    EDEMA, JJH; STOCK, HT; KELLOGG, RM; SMEETS, WJJ; SPEK, AL

    1993-01-01

    Reaction of a dithiol with B(OH)3 and base in MeOH followed by reaction with xylylene dibromides proceeds selectively to give the corresponding ortho, meta or para-cyclophanes in good yield (70-86 %). The syntheses of examples of all three types of benzenophanes are discussed. The molecular

  3. Well acidizing

    Energy Technology Data Exchange (ETDEWEB)

    Street, E H

    1980-01-23

    The apparatus relates in particular to a well-treating process in which an aqueous acid solution having a pH of < 2 is injected into a subterranean reservoir in a manner such that materials that contain ferric ions are present in the acid and, as the acid reacts within the reservoir and attains a pH exceeding 3, tend to be precipitated as ferric ion-containing solid materials that may plug the pores of the reservoir. Such a precipitation is prevented by dissolving in the acid solution an amount of 5-sulfosalicylic acid which is at least sufficient to sequester significant proportions of ferric ions when the pH of the acid is from 0.5 to 3 but is less than enough to cause a significant salting-out of solid materials, and an amount of citric acid which is at least sufficient to sequester significant proportions of ferric ions when the pH of the acid is from 3 to 6 but is less than enough to precipitate a significant amount of calcium citrate. The amount of the 5-sulfosalicylic acid may be from 0.01 to 0.05 moles/l and the amount of citric acid is from 0.001 to 0.009 moles/l. 11 claims.

  4. Ibotenic acid and thioibotenic acid

    DEFF Research Database (Denmark)

    Hermit, Mette B; Greenwood, Jeremy R; Nielsen, Birgitte

    2004-01-01

    In this study, we have determined and compared the pharmacological profiles of ibotenic acid and its isothiazole analogue thioibotenic acid at native rat ionotropic glutamate (iGlu) receptors and at recombinant rat metabotropic glutamate (mGlu) receptors expressed in mammalian cell lines....... Thioibotenic acid has a distinct pharmacological profile at group III mGlu receptors compared with the closely structurally related ibotenic acid; the former is a potent (low microm) agonist, whereas the latter is inactive. By comparing the conformational energy profiles of ibotenic and thioibotenic acid...... with the conformations preferred by the ligands upon docking to mGlu1 and models of the other mGlu subtypes, we propose that unlike other subtypes, group III mGlu receptor binding sites require a ligand conformation at an energy level which is prohibitively expensive for ibotenic acid, but not for thioibotenic acid...

  5. Immobilized laccase mediated dye decolorization and transformation pathway of azo dye acid red 27.

    Science.gov (United States)

    Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

    2015-01-01

    Laccases have good potential as bioremediating agents and can be used continuously in the immobilized form like many other enzymes. In the present study, laccase from Cyathus bulleri was immobilized by entrapment in Poly Vinyl Alcohol (PVA) beads cross-linked with either nitrate or boric acid. Immobilized laccase was used for dye decolorization in both batch and continuous mode employing a packed bed column. The products of degradation of dye Acid Red 27 were identified by LC MS/MS analysis. The method led to very effective (90%) laccase immobilization and also imparted significant stability to the enzyme (more than 70% after 5 months of storage at 4°C). In batch decolorization, 90-95% decolorization was achieved of the simulated dye effluent for up to 10-20 cycles. Continuous decolorization in a packed bed bioreactor led to nearly 90% decolorization for up to 5 days. The immobilized laccase was also effective in decolorization and degradation of Acid Red 27 in the presence of a mediator. Four products of degradation were identified by LC-MS/MS analysis. The immobilized laccase in PVA-nitrate was concluded to be an effective agent in treatment of textile dye effluents.

  6. Formic acid

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, H; Laing, B

    1921-12-03

    The production of formic acid by the oxidation of methane with a metallic oxide or by the interaction of carbon monoxide and water vapor in the presence of a catalyst, preferably a metallic oxide, is described along with the destructive distillation of carbonaceous material in the preesnce of formic acid vapor for the purpose of increasing the yield of condensible hydrocarbons.

  7. Lipoic Acid

    Directory of Open Access Journals (Sweden)

    Ramazan Tetikcok

    2015-09-01

    Full Text Available Lipoic acid, which is defined as a miralce antioxidan, is used by many departments. Eventhough clinical using data are very limited , it is used in treatment of diabetic neuropathy, physical therapy and rehabilitation clinic, dermatology clinic, geriatric clinics. It has usage area for cosmetic purposes. Although there are reports there are the direction of the effectiveness in these areas, the works done are not enough. Today lipoic acid , used in many areas ,is evaluated as universal antioxidant [J Contemp Med 2015; 5(3.000: 206-209

  8. Mefenamic Acid

    Science.gov (United States)

    Mefenamic acid comes as a capsule to take by mouth. It is usually taken with food every 6 hours as needed for up to 1 week. Follow ... pain vomit that is bloody or looks like coffee grounds black, tarry, or bloody stools slowed breathing ...

  9. Acid rain. Les pluies acides

    Energy Technology Data Exchange (ETDEWEB)

    Curren, T

    1979-11-28

    This report was produced for the use of Members of Parliament and House of Commons committees. The document describes the formation of acid rain, emissions of acidifying pollutants in North America, the growth of the problem and its environmental effects on aquatic and terrestrial ecosystems, human health and man-made structures. Areas of Canada which are most susceptible are identified. Actions taken by Parliament are given, including the formation of a sub-committee on acid rain and the passing of Bill C-51 in 1980 to amend the Clean Air Act, bringing it closer to a similar law in the U.S. A chronology of government responses to acid rain at the international, national and provincial level, is given. The most recent government actions included the passing of the US Clean Air Act by the Senate, the amending of the act into law, and commencement of negotiations to develop a Canada-US Air Quality Accord. 10 refs.

  10. Levulinic acid

    Directory of Open Access Journals (Sweden)

    Barbara Hachuła

    2013-09-01

    Full Text Available The title compound (systematic name: 4-oxopentanoic acid, C5H8O3, is close to planar (r.m.s. deviation = 0.0762 Å. In the crystal, the molecules interact via O—H...O hydrogen bonds in which the hydroxy O atoms act as donors and the ketone O atoms in adjacent molecules as acceptors, forming C(7 chains along [20-1].

  11. Acid-base behavior in hydrothermal processing of wastes. 1997 annual progress report

    International Nuclear Information System (INIS)

    1997-01-01

    'A major obstacle to the development of hydrothermal technology for treating DOE wastes has been a lack of scientific knowledge of solution chemistry, thermodynamics and transport phenomena. The progress over the last year is highlighted in the following four abstracts from manuscripts which have been submitted to journals. The authors also have made considerable progress on a spectroscopic study of the acid-base equilibria of Cr(VI). They have utilized novel spectroscopic indicators to study acid-base equilibria up to 380 C. Until now, very few systems have been studied at such high temperatures, although this information is vital for hydrothermal processing of wastes. The pH values of aqueous solutions of boric acid and KOH were measured with the optical indicator 2-naphthol at temperatures from 300 to 380 C. The equilibrium constant Kb-l for the reaction B(OH)3 + OH - = B(OH) -4 was determined from the pH measurements and correlated with a modified Born model. The titration curve for the addition of HCl to sodium borate exhibits strong acid-strong base behavior even at 350 C and 24.1 MPa. At these conditions, aqueous solutions of sodium borate buffer the pH at 9.6 t 0.25. submitted to Ind. Eng. Chem. Res. Acetic Acid and HCl Acid-base titrations for the KOH-acetic acid or NH 3 -acetic acid systems were monitored with the optical indicator 2-naphthoic acid at 350 C and 34 MPa, and those for the HCl;Cl- system with acridine at 380 C and up to 34 MPa (5,000 psia ). KOH remains a much stronger base than NH,OH at high temperature. From 298 K to the critical temperature of water, the dissociation constant for HCl decreases by 13 orders of magnitude, and thus, the basicity of Cl - becomes significant. Consequently, the addition of NaCl to HCl raises the pH. The pH titration curves may be predicted with reasonable accuracy from the relevant equilibrium constants and Pitzer''s formulation of the Debye- Htickel equation for the activity coefficients.'

  12. Understanding Acid Rain

    Science.gov (United States)

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  13. Capillary electrophoresis determination of glucosamine in nutraceutical formulations after labeling with anthranilic acid and UV detection.

    Science.gov (United States)

    Volpi, Nicola

    2009-04-05

    A new robust CE method for the determination of the glucosamine (GlcN) content in nutraceutical formulations is described after its derivatization with anthranilic acid (2-aminobenzoic acid, AA). The CE separation of derivatized GlcN with AA was performed on an uncoated fused-silica capillary tube (50 microm I.D.) using an operating pH 7.0 buffer of 150 mM boric acid/50 mM NaH2PO4 and UV detection at 214 nm. The method was validated for specificity, linearity, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ). The detector response for GlcN was linear over the selected concentration range from 240 to 2400 pg (40-400 microg/mL) with a correlation coefficient greater than 0.980. The intra- and inter-day variations (CV%) were between 0.5 and 0.9 for migration time, and between 2.8 and 4.3 for peak area, respectively. The LOD and the LOQ of the method were approximately 200 and 500 pg, respectively. The intra- and inter-day accuracy was estimated to range from 2.8% to 5.1%, while the percent recoveries of GlcN in formulations were calculated to be about 100% after simple centrifugation for 10 min, lyophilization and derivatization with AA. The CE method was applied to the determination of GlcN content, in the form of GlcN-hydrochloride or GlcN-sulfate, of several nutraceutical preparations in the presence of other ingredients, i.e. chondroitin sulfate, vitamin C and/or methylsulfonylmethane (MSM) as well as salts and other agents. The quantitative results obtained were in total conformity with the label claims.

  14. The acidic functional groups of humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shanxiang, Li; Shuhe, Sun; Zhai Zongxi, Wu Qihu

    1983-09-01

    The acidic functional groups content, pK value, DELTAH and DELTAS of humic acid (HA) and nitro-humic acid (NHA) were determined by potentiometry, conductometry and calorimetric titration. The thermodynamic parameters of carboxylic groups and phenolic hydroxyl groups of humic acid are similar to that of simple hydroxy-benzoic acid. The configuration sites of acidic functional groups in humic acid from different coals are different. The carbonyl groups on aromatic rings are probably ortho to phenolic -OH for HA and NHA extracted from Huangxian's brown coal and Japanese lignite, while those from Lingshi's weathered coal are not. The weak -COOH groups of the latter possess higher chemical activity. The -COOH content in HA increases, phenolic -OH group decreases and the chemical acidity of acidic functional groups increases when HA is oxidized by nitric acid. (14 refs.)

  15. Okadaic acid

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H; Severinsen, Mai C K

    2014-01-01

    are the hallmark of phospholipidosis, a pathological condition characterized by lysosomal phospholipid accumulation. Phospholipidosis is observed in acquired lysosomal storage diseases and is induced by a large number of cationic amphiphilic drugs. Unlike the latter, however, OA does not act by accumulating...... in acidic organelles, implying a different toxic mechanism of action. We propose that rapid induction of LBs, an indicator of phospholipidosis, should be included in the future toxicity profile of OA....... hyper protein phosphorylation, but no detectable loss of cell polarity or cytoskeletal integrity of the enterocytes. Using a fluorescent membrane marker, FM dye, endocytosis from the brush border was affected by the toxin. Although constitutive uptake into subapical terminal web-localized early...

  16. [Teichoic acids from lactic acid bacteria].

    Science.gov (United States)

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  17. Method of processing radioactive liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Y; Kikuchi, M; Funabashi, K; Yusa, H; Horiuchi, S

    1978-12-21

    Purpose: To decrease the volume of radioactive liquid wastes essentially consisting of sodium hydroxide and boric acid. Method: The concentration ratio of sodium hydroxide to boric acid by weight in radioactive liquid wastes essentially consisting of sodium hydroxide and boric acid is adjusted in the range of 0.28 - 0.4 by means of a pH detector and a sodium concentration detector. Thereafter, the radioactive liquid wastes are dried into powder and then discharged.

  18. Plasma amino acids

    Science.gov (United States)

    Amino acids blood test ... types of methods used to determine the individual amino acid levels in the blood. ... test is done to measure the level of amino acids in the blood. An increased level of a ...

  19. Uric acid - urine

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003616.htm Uric acid urine test To use the sharing features on ... are no risks with this test. Images Uric acid test Uric acid crystals References Burns CM, Wortmann RL. Clinical ...

  20. Uric acid test (image)

    Science.gov (United States)

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... for testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  1. Methylmalonic acid blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003565.htm Methylmalonic acid blood test To use the sharing features on this page, please enable JavaScript. The methylmalonic acid blood test measures the amount of methylmalonic acid in the ...

  2. Facts about Folic Acid

    Science.gov (United States)

    ... Information For… Media Policy Makers Facts About Folic Acid Language: English (US) Español (Spanish) Recommend on Facebook ... of the baby’s brain and spine. About folic acid Folic acid is a B vitamin. Our bodies ...

  3. Acid distribution in phosphoric acid fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Okae, I.; Seya, A.; Umemoto, M. [Fuji Electric Co., Ltd., Chiba (Japan)

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  4. Enantioseparation of dansyl amino acids and dipeptides by chiral ligand exchange capillary electrophoresis based on Zn(II)-L-hydroxyproline complexes coordinating with γ-cyclodextrins.

    Science.gov (United States)

    Mu, Xiaoyu; Qi, Li; Qiao, Juan; Yang, Xinzheng; Ma, Huimin

    2014-10-10

    A chiral ligand exchange capillary electrophoresis (CLE-CE) method using Zn(II) as the central ion and L-4-hydroxyproline as the chiral ligand coordinating with γ-cyclodextrin (γ-CD) was developed for the enantioseparation of amino acids (AAs) and dipeptides. The effects of various separation parameters, including the pH of the running buffer, the ratio of Zn(II) to L-4-hydroxyproline, the concentration of complexes and cyclodextrins (CDs) were systematically investigated. After optimization, it has been found that eight pairs of labeled AAs and six pairs of labeled dipeptides could be baseline-separated with a running electrolyte of 100.0mM boric acid, 5.0mM ammonium acetate, 3.0mM Zn(II), 6.0mM L-hydroxyproline and 4.0mM γ-CD at pH 8.2. The quantitation of AAs and dipeptides was conducted and good linearity (r(2)≥0.997) and favorable repeatability (RSD≤3.6%) were obtained. Furthermore, the proposed method was applied in determining the enantiomeric purity of AAs and dipeptides. Meanwhile, the possible enantiorecognition mechanism based on the synergistic effect of chiral metal complexes and γ-CD was explored and discussed briefly. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. The development of radioactive waste treatment technology (III)

    International Nuclear Information System (INIS)

    Kim, Joon Hyung; Jung, Ki Jung; Lee, Kune Woo; Park, Hun Hwee

    1991-03-01

    Most PWR stations have experienced leakages of boric acid and oil into liquid radwaste systems. Typically, these wastes have been concentrated by an evaporator system. Based on operating plant experiences, boric acid and oil are the majority of the solid loading for disposal and tend to decrease the efficiency significantly. The objective of these studies is to develop pretreatment techniques for the recovery of boric acid and for the removal of oil from such wastes for improving the evaporator performance. To these objectives, lab. scale reverse osmosis (RO) membrane and filtration/coalescence processes are introduced, which can separate boric acid and oil into waste streams. (Author)

  6. Citric acid urine test

    Science.gov (United States)

    Urine - citric acid test; Renal tubular acidosis - citric acid test; Kidney stones - citric acid test; Urolithiasis - citric acid test ... No special preparation is necessary for this test. But the results ... test is usually done while you are on a normal diet. Ask your ...

  7. Boron-containing acids: preliminary evaluation of acute toxicity and access to the brain determined by Raman scattering spectroscopy.

    Science.gov (United States)

    Soriano-Ursúa, Marvin A; Farfán-García, Eunice D; López-Cabrera, Yessica; Querejeta, Enrique; Trujillo-Ferrara, José G

    2014-01-01

    Boron-containing compounds (BCCs), particularly boron containing acids (BCAs), have become attractive moieties or molecules in drug development. It has been suggested that when functional groups with boron atoms are added to well-known drugs, the latter are conferred with greater potency and efficacy in relation to their target receptors. However, the use of BCAs in drug development is limited due to the lack of a toxicological profile. Consequently, the aim of the present study was to evaluate the acute toxicity of boric and boronic acids. Thus, a determination was made of the lethal dose (LD50) of test compounds in male CD1 mice, as well as the effective dose required to negatively affect spontaneous motor activity and to produce notable behavioral abnormalities. After treatment of animals at different doses, macroscopic observations were made from a necropsy, and Raman scattering spectroscopic studies were carried out on brain tissue samples. In general, the results show that most of the tested BCAs have very low toxicity, evidenced by the high doses required to induce notable toxic effects (greater than 100 mg/kg of body weight for all compounds, except for 3-thyenilboronic acid). Such toxic effects, presumably mediated by action on the CNS, include eye damage, gastrointestinal effects (e.g., gastric-gut dilatation and fecal retention), sedation, hypnosis and/or trembling. This preliminary toxicological profile suggests that BCAs can be considered potential therapeutic agents or moieties to be added to other compounds in the development of new drugs. Future studies are required to explore possible chronic toxicity of BCCs. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Acid Deposition Phenomena

    International Nuclear Information System (INIS)

    Ramadan, A.E.K.

    2004-01-01

    Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H 2 SO 4 ) and nitric acids (HNO 3 ), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  9. Effect of the calcium, boron and sulphur in pre harvest applications over the severity of anthracnose(Colletotrichum gloeosporioides Penz.) and the fruit's quality of two papaya's varieties in Perez Zeledon

    International Nuclear Information System (INIS)

    Montealegre Perez, Eduardo Antonio

    2005-01-01

    This research established the effect of the calcium, boron and sulphur in pre harvest applications over the severity of anthracnosis (Colletotrichum gloeosporioides Penz.) and the fruit's quality of two papaya's varieties, one creole and a hibrido in Perez Zeledon. The treatments were the folloguings: oxide of calcium plus dolomite, oxide of calcium plus boric acid plus dolomite, boric acid plus sulphate of potassium and dolomite, boric acid less dolomite and witness. The utilized sources were nitrate of calcium, boric acid and sulphate of potassium. The evaluations were realized both in the rainy season like in the dry season. There were evaluated: severity of anthracnosis, weight of the fruits, total soluble solids, shell's hardness, and stability of the flesh. The experimental design utilized was a complete block at random. There were got that the applications of oxide of calcium and boric acid less dolomite decreased the severity of the disease in the papaya's fruits, while that the boric acid plus sulphate tend to increase the disease. The treatment of boric acid plus sulphate decreased the weight of the fruits both in the rainy and dry season. Besides this treatment decreased the hardness of the shell, while that the treatments with boron increased that. Also the treatments with boric acid plus dolomite and boric acid less dolomite, increased the levels of total soluble solids in the papaya's fruits in the two varieties. Finally; the treatments: oxide of calcium plus boric acid and boric acid plus sulphate decreased the stability of the flesh in both varieties and both evaluated seasons, while the treatment with oxide of calcium increased the stability of the flesh in the hibrido during the dry season. (Author) [es

  10. Acid Lipase Disease

    Science.gov (United States)

    ... of Neurological Disorders and Stroke conducts and supports research to understand lipid storage diseases such as acid lipase deficiency and ... of Neurological Disorders and Stroke conducts and supports research to understand lipid storage diseases such as acid lipase deficiency and ...

  11. Lactic acid test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003507.htm Lactic acid test To use the sharing features on this page, please enable JavaScript. Lactic acid is mainly produced in muscle cells and red ...

  12. Amino Acid Metabolism Disorders

    Science.gov (United States)

    ... this process. One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple syrup urine disease. Amino acids are "building blocks" that join together to form ...

  13. Folic Acid and Pregnancy

    Science.gov (United States)

    ... Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Folic Acid and Pregnancy KidsHealth / For Parents / Folic Acid and Pregnancy Print ...

  14. Omega-6 Fatty Acids

    Science.gov (United States)

    Omega-6 fatty acids are types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean oils. Other types of omega-6 fatty acids are found in black currant seed, borage seed, ...

  15. Hydrochloric acid poisoning

    Science.gov (United States)

    Hydrochloric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe damage, such ... poisoning due to swallowing or breathing in hydrochloric acid. This article is for information only. Do NOT ...

  16. Aminolevulinic Acid Topical

    Science.gov (United States)

    Aminolevulinic acid is used in combination with photodynamic therapy (PDT; special blue light) to treat actinic keratoses (small crusty ... skin cancer) of the face or scalp. Aminolevulinic acid is in a class of medications called photosensitizing ...

  17. Zoledronic Acid Injection

    Science.gov (United States)

    Zoledronic acid (Reclast) is used to prevent or treat osteoporosis (condition in which the bones become thin and weak ... of life,' end of regular menstrual periods). Zoledronic acid (Reclast) is also used to treat osteoporosis in ...

  18. Azelaic Acid Topical

    Science.gov (United States)

    Azelaic acid gel and foam is used to clear the bumps, lesions, and swelling caused by rosacea (a skin ... redness, flushing, and pimples on the face). Azelaic acid cream is used to treat the pimples and ...

  19. Aminocaproic Acid Injection

    Science.gov (United States)

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  20. Deoxycholic Acid Injection

    Science.gov (United States)

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  1. Amino acids and proteins

    NARCIS (Netherlands)

    van Goudoever, Johannes B.; Vlaardingerbroek, Hester; van den Akker, Chris H.; de Groof, Femke; van der Schoor, Sophie R. D.

    2014-01-01

    Amino acids and protein are key factors for growth. The neonatal period requires the highest intake in life to meet the demands. Those demands include amino acids for growth, but proteins and amino acids also function as signalling molecules and function as neurotransmitters. Often the nutritional

  2. Acid Rain Study Guide.

    Science.gov (United States)

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  3. Immunoglobulin and fatty acids

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising 0.1-10 w/w % immunoglobulin (Ig), 4-14 w/w % saturated fatty acids, 4-14 w/w % mono-unsaturated fatty acids and 0-5 w/w % poly-unsaturated fatty acids, wherein the weight percentages are based on the content of dry matter in the composition...

  4. The Acid Rain Reader.

    Science.gov (United States)

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  5. Stomach acid test

    Science.gov (United States)

    Gastric acid secretion test ... of the cells in the stomach to release acid. The stomach contents are then removed and analyzed. ... 3.5). These numbers are converted to actual acid production in units of milliequivalents per hour (mEq/ ...

  6. The role of calcium, silicon and salicylic acid treatment in protection of canola plants against boron toxicity stress.

    Science.gov (United States)

    Metwally, Ashraf M; Radi, Abeer A; El-Shazoly, Rasha M; Hamada, Afaf M

    2018-01-22

    Boron (B) toxicity often limits crop yield and the quality of production in agricultural areas. Here, we investigated the effects of calcium (Ca), silicon (Si) and salicylic acid (SA) on development of B toxicity, B allocation in canola (Brassica napus cultivar Sarw 4) and its role in non-enzymatic antioxidants in relation to yield of this cultivar under B toxicity. Canola seedlings were subjected to four B levels induced by boric acid in the absence or presence of Ca, Si and SA. The results showed that Ca, Si and SA addition ameliorated the inhibition in canola growth, water content (WC), and improved siliqua number, siliqua weight and seed index. The B content in shoots and roots and total B accumulation in the whole plant were increased in control plants under B-toxicity-stress, and these parameters were significantly decreased by addition of Ca, Si and SA. The shoot ascorbate pool (ascorbate, AsA, and dehydroascorbate, DHA), α-tocopherol and phenolics (free and bound) were increased under B toxicity, and were significantly decreased in most cases by addition of Ca, Si and SA, except α-tocopherol, which increased at low B levels (0, 25 and 50 mg kg soil -1 ). The glutathione content did not obviously change by B stress, while added Ca, Si and SA inhibited its accumulation under B stress. In addition, B toxicity reduced the shoot flavonoids content; however, this reduction was not alleviated by the use of Ca, Si and SA treatments. It could be concluded that growth and yield of canola plants grown under high B concentration improved after external application of Ca, Si or SA.

  7. Acidic Ionic Liquids.

    Science.gov (United States)

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

  8. Process for the preparation of lactic acid and glyceric acid

    Science.gov (United States)

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  9. Amino acids in the sedimentary humic and fulvic acids

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    acids in the coastal Arabian Sea sediments: whereas amino acids content of fulvic acids was lower than that of humic acids in the coastal sediments of Bay of Bengal. Slope sedimentary humic acids were relatively enriched in amino acids as compared...

  10. 78 FR 20029 - Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance...

    Science.gov (United States)

    2013-04-03

    ..., Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of castor oil, polymer with adipic acid, linoleic acid... pesticide formulation. Advance Polymer Technology submitted a petition to EPA under the Federal Food, Drug...

  11. Characteristics of β-glucosidase production by Paecilomyces variotii ...

    African Journals Online (AJOL)

    This study reports the potential application of Paecilomyces variotii immobilized in calcium alginate beads as a sensing element in the analysis of boric acid. In the presence of boric acid, β-glucosidase production of P. variotii was inhibited and the changes of β-glucosidase concentration were correlated to the ...

  12. Bile acid sequestrants

    DEFF Research Database (Denmark)

    Hansen, Morten; Sonne, David P; Knop, Filip K

    2014-01-01

    Bile acids are synthesized in the liver from cholesterol and have traditionally been recognized for their role in absorption of lipids and in cholesterol homeostasis. In recent years, however, bile acids have emerged as metabolic signaling molecules that are involved in the regulation of lipid...... and glucose metabolism, and possibly energy homeostasis, through activation of the bile acid receptors farnesoid X receptor (FXR) and TGR5. Bile acid sequestrants (BASs) constitute a class of drugs that bind bile acids in the intestine to form a nonabsorbable complex resulting in interruption...... of the enterohepatic circulation. This increases bile acid synthesis and consequently reduces serum low-density lipoprotein cholesterol. Also, BASs improve glycemic control in patients with type 2 diabetes. Despite a growing understanding of the impact of BASs on glucose metabolism, the mechanisms behind their glucose...

  13. Production of structured lipids by acidolysis of an EPA-enriched fish oil and caprylic acid in a packed bed reactor: analysis of three different operation modes.

    Science.gov (United States)

    González Moreno, P A; Robles Medina, A; Camacho Rubio, F; Camacho Páez, B; Molina Grima, E

    2004-01-01

    Structured triacylglycerols (ST) enriched in eicosapentaenoic acid (EPA) in position 2 of the triacylglycerol (TAG) backbone were synthesized by acidolysis of a commercially available EPA-rich oil (EPAX4510, 40% EPA) and caprylic acid (CA), catalyzed by the 1,3-specific immobilized lipase Lipozyme IM. The reaction was carried out in a packed bed reactor (PBR) operating in two ways: (1) by recirculating the reaction mixture from the exit of the bed to the substrate reservoir (discontinuous mode) and (2) in continuous mode, directing the product mixture leaving the PBR to a product reservoir. By operating in these two ways and using a simple kinetic model, representative values for the apparent kinetic constants (kX) for each fatty acid (native, Li or odd, M) were obtained. The kinetic model assumes that the rate of incorporation of a fatty acid into TAG per amount of enzyme, rX (mole/(h g lipase)) is proportional to the extent of the deviation from the equilibrium for each fatty acid (i.e., the difference of concentration between the fatty acid in the triacylglycerol and the concentration of the same fatty acid in the triacylglycerol once the equilibrium of the acidolysis reaction is reached). The model allows comparing the two operating modes through the processing intensity, defined as mLt/(V[TG]0) and mL/(q[TG]0), for the discontinuous and continuous operation modes, respectively. In discontinuous mode, ST with 59.5% CA and 9.6% EPA were obtained. In contrast, a ST with 51% CA and 19.6% EPA were obtained when using the continuous operation mode. To enhance the CA incorporation when operating in continuous mode, a two-step acidolysis reaction was performed (third operation mode). This continuous two-step process yields a ST with a 64% CA and a 15% EPA. Finally, after purifying the above ST in a preparative silica gel column, impregnated with boric acid, a ST with 66.9% CA and 19.6% EPA was obtained. The analysis by reverse phase and Ag+ liquid chromatography of

  14. Citric Acid Alternative to Nitric Acid Passivation

    Science.gov (United States)

    Lewis, Pattie L. (Compiler)

    2013-01-01

    The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

  15. USGS Tracks Acid Rain

    Science.gov (United States)

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  16. Acidity of hydroxamic acids and amides

    Czech Academy of Sciences Publication Activity Database

    Böhm, S.; Exner, Otto

    2003-01-01

    Roč. 1, č. 7 (2003), s. 1176-1180 ISSN 1477-0520 R&D Projects: GA AV ČR IAA4072005 Institutional research plan: CEZ:AV0Z4055905 Keywords : hydroxamic acids * DFT calculations * isodesmic reactions Subject RIV: CC - Organic Chemistry

  17. Fusidic acid in dermatology

    DEFF Research Database (Denmark)

    Schöfer, Helmut; Simonsen, Lene

    1995-01-01

    Studies on the clinical efficacy of fusidic acid in skin and soft-tissue infections (SSTIs), notably those due to Staphylococcus aureus, are reviewed. Oral fusidic acid (tablets dosed at 250 mg twice daily, or a suspension for paediatric use at 20 mg/kg/day given as two daily doses) has shown goo...

  18. Characterization of acid tars

    International Nuclear Information System (INIS)

    Leonard, Sunday A.; Stegemann, Julia A.; Roy, Amitava

    2010-01-01

    Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain.

  19. Characterization of acid tars

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Sunday A., E-mail: sunday.leonard@ucl.ac.uk [Department of Civil Environmental and Geomatic Engineering, University College London, Chadwick Building, Gower Street, London, WC1E 6BT (United Kingdom); Stegemann, Julia A. [Department of Civil Environmental and Geomatic Engineering, University College London, Chadwick Building, Gower Street, London, WC1E 6BT (United Kingdom); Roy, Amitava [J. Bennett Johnston, Sr., Centre for Advance Microstructures and Devices (CAMD), 6980 Jefferson Highway, Louisiana State University, Baton Rouge, LA, 70806 (United States)

    2010-03-15

    Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain.

  20. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  1. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  2. Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  3. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds known as peptide nucleic acids, bind complementary DNA and RNA strands, and generally do so more strongly than the corresponding DNA or RNA strands while exhibiting increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from...

  4. Folic acid in diet

    Science.gov (United States)

    ... regularly removed from the body through urine, so excess amounts do not build up in the body. You should not get more than 1000 mcg per day of folic acid. Using higher levels of folic acid can mask vitamin B12 deficiency.

  5. Peptide Nucleic Acid Synthons

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  6. Locked nucleic acid

    DEFF Research Database (Denmark)

    Jepsen, Jan Stenvang; Sørensen, Mads D; Wengel, Jesper

    2004-01-01

    Locked nucleic acid (LNA) is a class of nucleic acid analogs possessing very high affinity and excellent specificity toward complementary DNA and RNA, and LNA oligonucleotides have been applied as antisense molecules both in vitro and in vivo. In this review, we briefly describe the basic...

  7. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Wesén, Clas; Sundin, Peter

    1997-01-01

    Chlorinated fatty acids have been found to be major contributors to organohalogen compounds in fish, bivalves, jellyfish, and lobster, and they have been indicated to contribute considerably to organohalogens in marine mammals. Brominated fatty acids have been found in marine sponges. Also...

  8. Amino Acid Crossword Puzzle

    Science.gov (United States)

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  9. Phosphates and phosphoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Becker, P [Compagnie Francaise de l' Azote, Paris (France)

    1983-01-01

    In chapter 8.5 the following aspects of uranium recovery are treated: basis of extraction process, extraction principle, solvents, strength of the acid to be treated, technology, main processes in use, impact of uranium recovery on phosphoric acid plants, and economics of uranium recovery plants.

  10. Omega-3 Fatty Acids

    Science.gov (United States)

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount of triglycerides (a fat- ... in people with very high triglycerides. Omega-3 fatty acids are in a class of medications called antilipemic ...

  11. Chlorogenic acid and caffeic acid are absorbed in humans

    NARCIS (Netherlands)

    Olthof, Margreet R.; Hollman, Peter C H; Katan, Martijn B.

    2001-01-01

    Chlorogenic acid, an ester of caffeic acid and quinic acid, is a major phenolic compound in coffee; daily intake in coffee drinkers is 0.5-1 g. Chlorogenic acid and caffeic acid are antioxidants in vitro and might therefore contribute to the prevention of cardiovascular disease. However, data on the

  12. Enzymatic formation of hexadecenoic acid from palmitic acid

    International Nuclear Information System (INIS)

    Nakano, Masao; Fujino, Yasuhiko

    1975-01-01

    Desaturation of palmitic acid was investigated in an enzyme system prepared from rat liver. 2-trans-Hexadecenoic acid as well as 9-cis-gexadecenoic acid (palmitoleic acid) were found to be formed as monoenoic acid in this system. (author)

  13. Lewis Acidic Ionic Liquids.

    Science.gov (United States)

    Brown, Lucy C; Hogg, James M; Swadźba-Kwaśny, Małgorzata

    2017-08-21

    Until very recently, the term Lewis acidic ionic liquids (ILs) was nearly synonymous with halometallate ILs, with a strong focus on chloroaluminate(III) systems. The first part of this review covers the historical context in which these were developed, speciation of a range of halometallate ionic liquids, attempts to quantify their Lewis acidity, and selected recent applications: in industrial alkylation processes, in supported systems (SILPs/SCILLs) and in inorganic synthesis. In the last decade, interesting alternatives to halometallate ILs have emerged, which can be divided into two sub-sections: (1) liquid coordination complexes (LCCs), still based on halometallate species, but less expensive and more diverse than halometallate ionic liquids, and (2) ILs with main-group Lewis acidic cations. The two following sections cover these new liquid Lewis acids, also highlighting speciation studies, Lewis acidity measurements, and applications.

  14. Acidity in rainfall

    International Nuclear Information System (INIS)

    Tisue, G.T.; Kacoyannakis, J.

    1975-01-01

    The reported increasing acidity of rainfall raises many interesting ecological and chemical questions. In spite of extensive studies in Europe and North America there are, for example, great uncertainties in the relative contributions of strong and weak acids to the acid-base properties of rainwater. Unravelling this and similar problems may require even more rigorous sample collection and analytical procedures than previously employed. Careful analysis of titration curves permits inferences to be made regarding chemical composition, the possible response of rainwater to further inputs of acidic components to the atmosphere, and the behavior to be expected when rainwater interacts with the buffers present in biological materials and natural waters. Rainwater samples collected during several precipitation events at Argonne National Laboratory during October and November 1975 have been analyzed for pH, acid and base neutralizing properties, and the ions of ammonium, nitrate, chloride, sulfate, and calcium. The results are tabulated

  15. Conjugated Fatty Acid Synthesis

    Science.gov (United States)

    Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

    2012-01-01

    Conjugated linolenic acids (CLNs), 18:3 Δ9,11,13, lack the methylene groups found between the double bonds of linolenic acid (18:3 Δ9,12,15). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 Δ9cis,11trans,13cis) or α-eleostearic acid (18:3 Δ9cis,11trans,13trans). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly α-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of α-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation. PMID:22451660

  16. Interações entre auxinas e ácido bórico, no enraizamento de estacas caulinares de Coffea arabica L. cv. Mundo Novo Interactions between auxins and boric acid in the rooting of stem cuttings Coffea arabica L. cv. "Mundo Novo"

    Directory of Open Access Journals (Sweden)

    E.O. Ono

    1992-01-01

    Full Text Available O presente trabalho teve como finalidade, estudar o efeito de auxinas e do boro no enraizamento de estacas caulinares de Coffea arabica L. cv. "Mundo Novo". As estacas foram retiradas de ramos ortotrópicos semi-lenhosos de cafeeiro, as quais foram tratadas durante 24 horas com soluções de IBA ou NAA e boro, e a mistura das três substâncias, resultando um total de 14 tratamentos. Para a avaliação do objetivo em questão, foram realizadas as seguintes observações, mediante coleta após 90 dias de plantio: número de estacas enraizadas e número de estacas com calos. Através dos resultados obtidos, pode-se concluir que, para obter um maior número de estacas enraizadas, é conveniente o tratamento com NAA à 100 ou 200 ppm mais boro.The present research had as purpose to study auxin and boron effects on rooting of Coffea arábica L. cv. "Mundo Novo" stem cuttings. The cuttings were taken from orthotropous semi-hardwood branches of coffee-tree, which were treated during 24 hours with IBA or NAA and boron solutions, and the mixture of the three substances, resulting a total of 14 treatments. The following observations were realized, taking the cuttings 90 days after planting: number of rooted cuttings and "callus" formation per cutting. It can be concluded that to obtain a higher number of rooted cuttings, the treatment with NAA at 100 or 200 ppm plus boron is the most suitable.

  17. Resposta à adubação com uréia, cloreto de potássio e ácido bórico em mudas abacaxizeiro'Smooth Cayenne' Response to fertilization with urea, potassium chloride and boric acid in the 'Smooth Cayenne' pineapple plants

    Directory of Open Access Journals (Sweden)

    Ruimário Inácio Coelho

    2007-04-01

    Full Text Available Mudas do abacaxizeiro (Ananas comosus L., cultivar Smooth Cayenne, obtidas por seccionamento de caule, foram submetidas à adubação foliar com soluções em diferentes concentrações de uréia, KCl e H3BO3. O delineamento utilizado foi fatorial fracionado do tipo (1/55³, com três tipos de adubo e cinco concentrações, num total de 25 tratamentos, que consistiram de combinações de concentrações de 0; 2,5; 5,0; 7,5 e 10 g L-1 de uréia e KCl, e 0; 0,5; 1,0; 1,5 e 2,0 g L-1 de H3BO3. Os tratamentos foram iniciados nove semanas após o plantio das seções do caule, com 26 pulverizações semanais para a uréia e KCl e 4 pulverizações mensais para o H3BO3. Verificou-se crescimento linear positivo para as características: altura das brotações, número de folhas, área foliar, massa seca e fresca das mudas, em resposta a níveis crescentes de uréia. Não foi observado efeito do KCl e H3BO3 para nenhuma das características de crescimento avaliadas. As mudas adubadas com 10 g L-1 de uréia atingiram altura de 40 cm e massa fresca de 242 g no 9º mês após o plantio das seções.Suckers of the pineapple plant (Ananas comosus L., Smooth Cayenne cv., obtained by stem sectioning, were submitted to leaf fertilization with solutions at different concentrations of urea, KCl and H3BO3. The fractionated factorial design of the type (1/55³ was used, with three fertilizer types and five concentrations, totalizing 25 treatments that consisted of combination of concentrations (0; 2.5; 5.0; 7.5 and 10 g L-1 of urea and KCl, as well as 0; 0.5; 1.0; 1.5 and 2.0 g L-1 of H3BO3. The treatments began nine weeks after planting the stem sections. Twenty six sprays of urea and KCl were weekly applied as well as four monthly sprays of H3BO3. Positive linear growth was verified for the following characteristics: sprouting heights, leaf numbers, leaf area, dry and fresh matter of the suckers in response to increasing urea levels. No effect of KCl and H3BO3 were observed for the growth characteristics under evaluation. The suckers fertilized with 10 g L-1 urea reached 40 cm height and 242 g fresh matter at the 9th month after planting the sections.

  18. Shoot and root responses of Trifolium vesiculosum to boron fertilization in an acidic Brazilian soil

    Directory of Open Access Journals (Sweden)

    Nerilde Favaretto

    2007-07-01

    Full Text Available To analyze the influence of boron fertilization on shoot and root growth of Trifolium vesiculosum (arrowleaf clover, an acid soil profile (60 cm depth with 67% Al saturation was recreated in a column (three layers of 20 cm each. Lime and fertilizer (P and K were incorporated into the top 20 cm. The treatments consisted of six boron rates where boric acid was mixed throughout the profile. Addition of boron to soil with low pH and high Al increased the root and shoot growth, independent of the rate applied. Boron inhibited Al toxicity, but no effect was observed in the root length when Al was not present in the soil. It was also observed that there was more root growth below the plow layer (0-20 cm, suggesting better root distribution in the soil profile which could be important for the plant growth, especially under drought conditions.Estudos têm mostrado que o boro (B afeta o crescimento das raízes em solo ácido reduzindo a toxidez do alumínio (Al. Para analisar a influência do boro no crescimento da parte aérea e raízes do Trifolium Vesiculosum (trevo vesiculoso um perfil de solo ácido (60 cm de profundidade com 67% de saturação de Al foi recriado em uma coluna (três camadas com 20 cm cada. Calcário e adubos (P e K foram incorporados na camada de 0-20 cm. Os tratamentos consistiram de seis doses de boro sendo o ácido bórico incorporado em todo o perfil. A adubação com boro em solo com baixo pH e elevado Al aumentou o crescimento da parte aérea e raízes, no entanto, independente da dose aplicada. Boro pode inibir a toxidez de Al, porém não observou-se efeito no comprimento de raízes sem a presença de Al no solo. Observou-se também um grande aumento no crescimento de raízes abaixo da camada arável (0-20 cm, fornecendo uma melhor distribuição de raízes no perfil do solo, o que pode ser importante para o crescimento da planta especialmente em condição de seca.

  19. Glycosyltransferase glycosylating flavokermesic acid and/or kermesic acid

    DEFF Research Database (Denmark)

    2016-01-01

    An isolated glycosyltransferase (GT) polypeptide capable of: (I) : conjugating glucose to flavokermesic acid (FK); and/or (II) : conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid.......An isolated glycosyltransferase (GT) polypeptide capable of: (I) : conjugating glucose to flavokermesic acid (FK); and/or (II) : conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid....

  20. GLYCOSYLTRANSFERASE GLYCOSYLATING FLAVOKERMESIC ACID AND/OR KERMESIC ACID

    DEFF Research Database (Denmark)

    2015-01-01

    An isolated glycosyltransferase (GT) polypeptide capable of: (I): conjugating glucose to flavokermesic acid (FK); and/or (II): conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid.......An isolated glycosyltransferase (GT) polypeptide capable of: (I): conjugating glucose to flavokermesic acid (FK); and/or (II): conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid....

  1. Waht is 'molybdic acid' or 'polymolybdic acid'?

    International Nuclear Information System (INIS)

    Tytko, K.H.; Baethe, G.; Mehmke, K.

    1987-01-01

    According to a comparative study of the literature, supplemented by well-aimed experimental investigations and equilibrium calculations, the terms 'molybdic acid' or 'polymolybdic acid', used for many substances, species, or solutions in the literature, are applicable to a species, a solution, and two solids: a) The monomeric molybdic acid, most probably having the formula MoO 2 (OH) 2 (H 2 O) 2 (= H 2 MoO 4 , aq), exists in (aqueous) solution only and never exceeds a concentration of ∼ 10 -3 M since at higher concentrations it reacts with other monomeric molybdenum(VI) species to give anionic or cationic polymers. b) A concentrated (> 0.1 M Mo VI ) aqueous molybdate solution of degree of acidification P = 2 (realized, e.g., by a solution of one of the Mo VI oxides; by any molybdate solutions whose cations have been exchanged by H 2 O + on a cation exchanger; by suitable acidification of a molybdate solution) contains 8 H 3 O + and the well-known polyanion Mo 36 O 112 (H 2 O) 16 8- exactly in the stoichiometric proportions. c) A glassy substance, obtained from an alkali metal salt-free solution prepared acording to (b), refers to the compound (H 3 O) 8 [Mo 36 O 112 (H 2 O) 16 ] · xH 2 O, x = 25 - 29. d) A solid having the ideal composition [(H 3 O)Mo 5 O 15 (OH)H 2 O · H 2 O] ∞ consists of a polymolybdate skeleton (the well-known 'decamolybdate' structure), in the tunnels of which H 3 O + and H 2 O are intercalated. The structure is very unstable if only H 3 O + cations are present, but it is enormously stabilized by a partial exchange of H 3 O + by certain alkali or alkaline earth metal cations. For the compounds MoO 3 , MoO 3 ·H 2 O, and MoO 3 · 2 H 2 O the term 'molybdic acid' is unjustified. The commercial product 'molybdic acid, ∼ 85% MoO 3 ' is the well-known polymolybdate (NH 4 ) 2 O · 4 MoO 3 with a layer structure of the polyanion. 84 refs. (author)

  2. Amino acid racemisation dating

    International Nuclear Information System (INIS)

    Murray-Wallace, C.V.

    1999-01-01

    The potential of the time-dependent amino acid racemisation reaction as a method of age assessment was first reported by Hare and Abelson (1968). They noted that in specimens of the bivalve mollusc Mercenaria sp., greater concentrations of amino acids in the D-configuration with increasing fossil age. Hare and Abelson (1968) also reported negligible racemisation in a modern specimen of Mecanaria sp. On this basis they suggested that the extent of amino acid racemisation (epimerisation in the case of isoleucine) may be used to assess the age of materials within and beyond the range of radiocarbon dating. For the past thirty years amino acid racemisation has been extensively applied in Quaternary research as a method of relative and numeric dating, and a particularly large literature has emerged on the subject

  3. Amino Acids and Chirality

    Science.gov (United States)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  4. Acid Mine Drainage Treatment

    National Research Council Canada - National Science Library

    Fripp, Jon

    2000-01-01

    .... Acid mine drainage (AMD) can have severe impacts to aquatic resources, can stunt terrestrial plant growth and harm wetlands, contaminate groundwater, raise water treatment costs, and damage concrete and metal structures...

  5. Amoxicillin and Clavulanic Acid

    Science.gov (United States)

    ... in a class of medications called penicillin-like antibiotics. It works by stopping the growth of bacteria. Clavulanic acid ... It works by preventing bacteria from destroying amoxicillin. Antibiotics will not work for colds, flu, or other viral infections.

  6. Alpha Hydroxy Acids

    Science.gov (United States)

    ... or tenderness (8), chemical burns (6), and increased sunburn (3). The frequency of such reports for skin ... bear a statement that conveys the following information: Sunburn Alert: This product contains an alpha hydroxy acid ( ...

  7. Azetidinic amino acids

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Bunch, Lennart; Chopin, Nathalie

    2005-01-01

    A set of ten azetidinic amino acids, that can be envisioned as C-4 alkyl substituted analogues of trans-2-carboxyazetidine-3-acetic acid (t-CAA) and/or conformationally constrained analogues of (R)- or (S)-glutamic acid (Glu) have been synthesized in a diastereo- and enantiomerically pure form from...... of two diastereoisomers that were easily separated and converted in two steps into azetidinic amino acids. Azetidines 35-44 were characterized in binding studies on native ionotropic Glu receptors and in functional assays at cloned metabotropic receptors mGluR1, 2 and 4, representing group I, II and III...... beta-amino alcohols through a straightforward five step sequence. The key step of this synthesis is an original anionic 4-exo-tet ring closure that forms the azetidine ring upon an intramolecular Michael addition. This reaction was proven to be reversible and to lead to a thermodynamic distribution...

  8. Valproic Acid and Pregnancy

    Science.gov (United States)

    ... is possible. Studies have found that women with seizure disorders and women with bipolar disorder might have menstrual ... valproic acid to leave your body. Women with epilepsy or bipolar disorder who are planning a pregnancy ...

  9. [Acids in coffee. XI. The proportion of individual acids in the total titratable acid].

    Science.gov (United States)

    Engelhardt, U H; Maier, H G

    1985-07-01

    22 acids in ground roast coffees and instant coffees were determined by GLC of their silyl derivatives (after preseparation by gel electrophoresis) or isotachophoresis. The contribution to the total acidity (which was estimated by titration to pH 8 after cation exchange of the coffee solutions) was calculated for each individual acid. The mentioned acids contribute with 67% (roast coffee) and 72% (instant coffee) to the total acidity. In the first place citric acid (12.2% in roast coffee/10.7% in instant coffee), acetic acid (11.2%/8.8%) and the high molecular weight acids (8%/9%) contribute to the total acidity. Also to be mentioned are the shares of chlorogenic acids (9%/4.8%), formic acid (5.3%/4.6%), quinic acid (4.7%/5.9%), malic acid (3.9%/3%) and phosphoric acid (2.5%/5.2%). A notable difference in the contribution to total acidity between roast and instant coffee was found for phosphoric acid and pyrrolidonecarboxylic acid (0.7%/1.9%). It can be concluded that those two acids are formed or released from e.g. their esters in higher amounts than other acids during the production of instant coffee.

  10. Portable nucleic acid thermocyclers.

    Science.gov (United States)

    Almassian, David R; Cockrell, Lisa M; Nelson, William M

    2013-11-21

    A nucleic acid thermal cycler is considered to be portable if it is under ten pounds, easily carried by one individual, and battery powered. Nucleic acid amplification includes both polymerase chain reaction (e.g. PCR, RT-PCR) and isothermal amplification (e.g. RPA, HDA, LAMP, NASBA, RCA, ICAN, SMART, SDA). There are valuable applications for portable nucleic acid thermocyclers in fields that include clinical diagnostics, biothreat detection, and veterinary testing. A system that is portable allows for the distributed detection of targets at the point of care and a reduction of the time from sample to answer. The designer of a portable nucleic acid thermocycler must carefully consider both thermal control and the detection of amplification. In addition to thermal control and detection, the designer may consider the integration of a sample preparation subsystem with the nucleic acid thermocycler. There are a variety of technologies that can achieve accurate thermal control and the detection of nucleic acid amplification. Important evaluation criteria for each technology include maturity, power requirements, cost, sensitivity, speed, and manufacturability. Ultimately the needs of a particular market will lead to user requirements that drive the decision between available technologies.

  11. Fatty Acid Biosynthesis IX

    DEFF Research Database (Denmark)

    Carey, E. M.; Hansen, Heinz Johs. Max; Dils, R.

    1972-01-01

    # 1. I. [I-14C]Acetate was covalently bound to rabbit mammary gland fatty acid synthetase by enzymic transacylation from [I-14C]acetyl-CoA. Per mole of enzyme 2 moles of acetate were bound to thiol groups and up to I mole of acetate was bound to non-thiol groups. # 2. 2. The acetyl-fatty acid...... synthetase complex was isolated free from acetyl-CoA. It was rapidly hydrolysed at 30°C, but hydrolysis was greatly diminished at o°C and triacetic lactone synthesis occurred. In the presence of malonyl-CoA and NADPH, all the acetate bound to fatty acid synthetase was incorporated into long-chain fatty acids....... Hydrolysis of bound acetate and incorporation of bound acetate into fatty acids were inhibited to the same extent by guanidine hydrochloride. # 3. 3. Acetate was also covalently bound to fatty acid synthetase by chemical acetylation with [I-14C]acetic anhydride in the absence of CoASH. A total of 60 moles...

  12. Improving pitting corrosion resistance of aluminum by anodizing process

    International Nuclear Information System (INIS)

    John, P.; Khan, I.U.

    2013-01-01

    Summary: Anodizing of aluminum was studied in sulphuric/citric/boric acid electrolyte system to improve pitting corrosion resistance. Maximum oxide film thickness was obtained using 5% sulphuric acid, 3% citric acid and 0.5% boric acid electrolyte composition. The corrosion resistance of aluminum sample was determined to find the effectiveness of oxide coating by potentiodynamic polarization test. The surface morphology of aluminum samples was investigated using scanning electron microscope (SEM) before and after corrosion test. It was found that the coated aluminum sample obtained by anodizing in sulphuric/citric/boric acid electrolyte system exhibited better pitting corrosion resistance with no significant difference in surface morphology. (author)

  13. Acidification and Acid Rain

    Science.gov (United States)

    Norton, S. A.; Veselã½, J.

    2003-12-01

    Air pollution by acids has been known as a problem for centuries (Ducros, 1845; Smith, 1872; Camuffo, 1992; Brimblecombe, 1992). Only in the mid-1900s did it become clear that it was a problem for more than just industrially developed areas, and that precipitation quality can affect aquatic resources ( Gorham, 1955). The last three decades of the twentieth century saw tremendous progress in the documentation of the chemistry of the atmosphere, precipitation, and the systems impacted by acid atmospheric deposition. Chronic acidification of ecosystems results in chemical changes to soil and to surface waters and groundwater as a result of reduction of base cation supply or an increase in acid (H+) supply, or both. The most fundamental changes during chronic acidification are an increase in exchangeable H+ or Al3+ (aluminum) in soils, an increase in H+ activity (˜concentration) in water in contact with soil, and a decrease in alkalinity in waters draining watersheds. Water draining from the soil is acidified and has a lower pH (=-log [H+]). As systems acidify, their biotic community changes.Acidic surface waters occur in many parts of the world as a consequence of natural processes and also due to atmospheric deposition of strong acid (e.g., Canada, Jeffries et al. (1986); the United Kingdom, Evans and Monteith (2001); Sweden, Swedish Environmental Protection Board (1986); Finland, Forsius et al. (1990); Norway, Henriksen et al. (1988a); and the United States (USA), Brakke et al. (1988)). Concern over acidification in the temperate regions of the northern hemisphere has been driven by the potential for accelerating natural acidification by pollution of the atmosphere with acidic or acidifying compounds. Atmospheric pollution ( Figure 1) has resulted in an increased flux of acid to and through ecosystems. Depending on the ability of an ecosystem to neutralize the increased flux of acidity, acidification may increase only imperceptibly or be accelerated at a rate that

  14. Why is hydrofluoric acid a weak acid?

    Science.gov (United States)

    Ayotte, Patrick; Hébert, Martin; Marchand, Patrick

    2005-11-08

    The infrared vibrational spectra of amorphous solid water thin films doped with HF at 40 K reveal a strong continuous absorbance in the 1000-3275 cm(-1) range. This so-called Zundel continuum is the spectroscopic hallmark for aqueous protons. The extensive ionic dissociation of HF at such low temperature suggests that the reaction enthalpy remains negative down to 40 K. These observations support the interpretation that dilute HF aqueous solutions behave as weak acids largely due to the large positive reaction entropy resulting from the structure making character of the hydrated fluoride ion.

  15. Acid Rain, pH & Acidity: A Common Misinterpretation.

    Science.gov (United States)

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  16. [Lipid synthesis by an acidic acid tolerant Rhodotorula glutinis].

    Science.gov (United States)

    Lin, Zhangnan; Liu, Hongjuan; Zhang, Jian'an; Wang, Gehua

    2016-03-01

    Acetic acid, as a main by-product generated in the pretreatment process of lignocellulose hydrolysis, significantly affects cell growth and lipid synthesis of oleaginous microorganisms. Therefore, we studied the tolerance of Rhodotorula glutinis to acetic acid and its lipid synthesis from substrate containing acetic acid. In the mixed sugar medium containing 6 g/L glucose and 44 g/L xylose, and supplemented with acetic acid, the cell growth was not:inhibited when the acetic acid concentration was below 10 g/L. Compared with the control, the biomass, lipid concentration and lipid content of R. glutinis increased 21.5%, 171% and 122% respectively when acetic acid concentration was 10 g/L. Furthermore, R. glutinis could accumulate lipid with acetate as the sole carbon source. Lipid concentration and lipid yield reached 3.20 g/L and 13% respectively with the initial acetic acid concentration of 25 g/L. The lipid composition was analyzed by gas chromatograph. The main composition of lipid produced with acetic acid was palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, including 40.9% saturated fatty acids and 59.1% unsaturated fatty acids. The lipid composition was similar to that of plant oil, indicating that lipid from oleaginous yeast R. glutinis had potential as the feedstock of biodiesel production. These results demonstrated that a certain concentration of acetic acid need not to be removed in the detoxification process when using lignocelluloses hydrolysate to produce microbial lipid by R. glutinis.

  17. Synthesis and anticonvulsant activity of novel bicyclic acidic amino acids

    DEFF Research Database (Denmark)

    Conti, Paola; De Amici, Marco; Joppolo Di Ventimiglia, Samuele

    2003-01-01

    Bicyclic acidic amino acids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

  18. Chemistry and electrochemistry in trifluoroacetic acid. Comparison with acetic acid

    International Nuclear Information System (INIS)

    Petit, Gerard

    1972-01-01

    As the trifluoroacetic acid is, with the acetic acid, one of most often used carboxylic acids as solvent, notably in organic chemistry, this research thesis addresses some relatively simple complexing and redox reactions to highlight the peculiar feature of this acid, and to explain its very much different behaviour with respect to acetic acid. The author develops the notion of acidity level in solvents of low dielectric constant. The second part addresses a specific solvent: BF 3 (CH 3 COOH) 2 . The boron trifluoride strengthens the acidity of acetic acid and modifies its chemical and physical-chemical properties. In the third part, the author compares solvent properties of CF 3 COOH and CH 3 COOH. Noticed differences explain why the trifluoroacetic acid is a more interesting reaction environment than acetic acid for reactions such as electrophilic substitutions or protein solubilisation [fr

  19. Domoic Acid Epileptic Disease

    Directory of Open Access Journals (Sweden)

    John S. Ramsdell

    2014-03-01

    Full Text Available Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis.

  20. Citric acid by fermentation

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed, R M

    1978-11-30

    Citric acid is produced in 2 stages, in the first of which Escherichia coli KG93 F-is cultured on a substrate consisting of whey permeate to which phosphate and nitrate or urea is added. In the second stage, Hansenula wickerhamii CBS 4308 is cultured on the culture solution from the first stage and the citric acid isolated in the usual manner. Thus, a whey permeate comprising fat 0.20, protein 0.05, lactose 5.0, lactic acid 0.1, and salts 0.6% (Ca 0.06, P 0.06, K 0.16, N 0.03, and NaCl 0.3%) was amended with 1.2 g phosphate/L and 1.0 g NO/sub 3/sup -///L. After introducing the whey permeate into a continuous fermentor, it was inoculated with E. coli K693 F- and allowed to incubate at 37/sup 0/ and pH 7 (Maintained with NH/sub 3/ gas) for 12 h with aeration, thereby producing concentration pyruvic acid. After an additional 6 h cultivation without aeration, the broth was transferred to another fermentor and there inoculated with H. wickerhamii CBS 4308. The second cultivation step was carried out at 30/sup 0/ and a pH of 5 for 24 h with the pH stabilized by NH/sub 3/ gas. To the second stage culture, 0.3 g Fe(CN)/sup 4 -//L was added. The yield of pyruvic acid in the first stage was 32 g/L and the final yield of citric acid was 43 g/L.

  1. 2-arylureidobenzoic acids

    DEFF Research Database (Denmark)

    Valgeirsson, Jon; Nielsen, Elsebet Ø; Peters, Dan

    2003-01-01

    A series of 2-arylureidobenzoic acids (AUBAs) was prepared by a short and effective synthesis, and the pharmacological activity at glutamate receptors was evaluated in vitro and in vivo. The compounds showed noncompetitive antagonistic activity at the kainate receptor subtype GluR5. The most potent...... on the benzoic acid moiety (ring A), whereas ring B tolerated a variety of substituents, but with a preference for lipophilic substituents. The most potent compounds had a 4-chloro substituent on ring A and 3-chlorobenzene (6b), 2-naphthalene (8h), or 2-indole (8k) as ring B and had IC(50) values of 1.3, 1...

  2. Whither Acid Rain?

    Directory of Open Access Journals (Sweden)

    Peter Brimblecombe

    2000-01-01

    Full Text Available Acid rain, the environmental cause célèbre of the 1980s seems to have vanished from popular conscience. By contrast, scientific research, despite funding difficulties, has continued to produce hundreds of research papers each year. Studies of acid rain taught much about precipitation chemistry, the behaviour of snow packs, long-range transport of pollutants and new issues in the biology of fish and forested ecosystems. There is now evidence of a shift away from research in precipitation and sulfur chemistry, but an impressive theoretical base remains as a legacy.

  3. Catalytic acetoxylation of lactic acid to 2-acetoxypropionic acid, en route to acrylic acid

    NARCIS (Netherlands)

    Beerthuis, R.; Granollers, M.; Brown, D.R.; Salavagione, H.J.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    We present an alternative synthetic route to acrylic acid, starting from the platform chemical lactic acid and using heterogeneous catalysis. To improve selectivity, we designed an indirect dehydration reaction that proceeds via acetoxylation of lactic acid to 2-acetoxypropionic acid. This

  4. Comparison of Buffer Effect of Different Acids During Sandstone Acidizing

    International Nuclear Information System (INIS)

    Shafiq, Mian Umer; Mahmud, Hisham Khaled Ben; Hamid, Mohamed Ali

    2015-01-01

    The most important concern of sandstone matrix acidizing is to increase the formation permeability by removing the silica particles. To accomplish this, the mud acid (HF: HCl) has been utilized successfully for many years to stimulate the sandstone formations, but still it has many complexities. This paper presents the results of laboratory investigations of different acid combinations (HF: HCl, HF: H 3 PO 4 and HF: HCOOH). Hydrofluoric acid and fluoboric acid are used to dissolve clays and feldspar. Phosphoric and formic acids are added as a buffer to maintain the pH of the solution; also it allows the maximum penetration of acid into the core sample. Different tests have been performed on the core samples before and after the acidizing to do the comparative study on the buffer effect of these acids. The analysis consists of permeability, porosity, color change and pH value tests. There is more increase in permeability and porosity while less change in pH when phosphoric and formic acids were used compared to mud acid. From these results it has been found that the buffer effect of phosphoric acid and formic acid is better than hydrochloric acid. (paper)

  5. Usnic acid controls the acidity tolerance of lichens

    International Nuclear Information System (INIS)

    Hauck, Markus; Juergens, Sascha-Rene

    2008-01-01

    The hypotheses were tested that, firstly, lichens producing the dibenzofuran usnic acid colonize substrates characterized by specific pH ranges, secondly, this preferred pH is in a range where soluble usnic acid and its corresponding anion occur in similar concentrations, and thirdly, usnic acid makes lichens vulnerable to acidity. Lichens with usnic acid prefer an ambient pH range between 3.5 and 5.5 with an optimum between 4.0 and 4.5. This optimum is close to the pK a1 value of usnic acid of 4.4. Below this optimum pH, dissolved SO 2 reduces the chlorophyll fluorescence yield more in lichens with than without their natural content of usnic acid. This suggests that usnic acid influences the acidity tolerance of lichens. The putative mechanism of the limited acidity tolerance of usnic acid-containing lichens is the acidification of the cytosol by molecules of protonated usnic acid shuttling protons through the plasma membrane at an apoplastic pH a1 . - Combined field and experimental data suggest that usnic acid makes lichens sensitive to acidity at pH <3.5

  6. [Studies on interaction of acid-treated nanotube titanic acid and amino acids].

    Science.gov (United States)

    Zhang, Huqin; Chen, Xuemei; Jin, Zhensheng; Liao, Guangxi; Wu, Xiaoming; Du, Jianqiang; Cao, Xiang

    2010-06-01

    Nanotube titanic acid (NTA) has distinct optical and electrical character, and has photocatalysis character. In accordance with these qualities, NTA was treated with acid so as to enhance its surface activity. Surface structures and surface groups of acid-treated NTA were characterized and analyzed by Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectrometry (FT-IR). The interaction between acid-treated NTA and amino acids was investigated. Analysis results showed that the lengths of acid-treated NTA became obviously shorter. The diameters of nanotube bundles did not change obviously with acid-treating. Meanwhile, the surface of acid-treated NTA was cross-linked with carboxyl or esterfunction. In addition, acid-treated NTA can catch amino acid residues easily, and then form close combination.

  7. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  8. Molecular interaction of pinic acid with sulfuric acid

    DEFF Research Database (Denmark)

    Elm, Jonas; Kurtén, Theo; Bilde, Merete

    2014-01-01

    We investigate the molecular interactions between the semivolatile α-pinene oxidation product pinic acid and sulfuric acid using computational methods. The stepwise Gibbs free energies of formation have been calculated utilizing the M06-2X functional, and the stability of the clusters is evaluated...... cluster. The involvement of more than one pinic acid molecule in a single cluster is observed to lead to the formation of favorable (pinic acid)2(H2SO4) and (pinic acid)2(H2SO4)2 clusters. The identified most favorable growth paths starting from a single pinic acid molecule lead to closed structures...

  9. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    Science.gov (United States)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  10. Koetjapic acid chloroform hemisolvate

    Directory of Open Access Journals (Sweden)

    Z. D. Nassar

    2010-06-01

    Full Text Available The asymmetric unit of the title compound, C30H46O4·0.5CHCl3, consists of one koetjapic acid [systematic name: (3R,4aR,4bS,7S,8S,10bS,12aS-7-(2-carboxyethyl-3,4b,7,10b,12a-pentamethyl-8-(prop-1-en-2-yl-1,2,3,4,4a,4b,5,6,7,8,9,10,10b,11,12,12a-hexadecahydrochrysene-3-carboxylic acid] molecule and one half-molecule of chloroform solvent, which is disordered about a twofold rotation axis. The symmetry-independent component is further disordered over two sites, with occupancies of 0.30 and 0.20. The koetjapic acid contains a fused four-ring system, A/B/C/D. The A/B, B/C and C/D junctions adopt E/trans/cis configurations, respectively. The conformation of ring A is intermediate between envelope and half-chair and ring B adopts an envelope conformation whereas rings C and D adopt chair conformations. A weak intramolecular C—H...O hydrogen bond is observed. The koetjapic acid molecules are linked into dimers by two pairs of intermolecular O—H...O hydrogen bonds. The dimers are stacked along the c axis.

  11. Microbial Propionic Acid Production

    Directory of Open Access Journals (Sweden)

    R. Axayacatl Gonzalez-Garcia

    2017-05-01

    Full Text Available Propionic acid (propionate is a commercially valuable carboxylic acid produced through microbial fermentation. Propionic acid is mainly used in the food industry but has recently found applications in the cosmetic, plastics and pharmaceutical industries. Propionate can be produced via various metabolic pathways, which can be classified into three major groups: fermentative pathways, biosynthetic pathways, and amino acid catabolic pathways. The current review provides an in-depth description of the major metabolic routes for propionate production from an energy optimization perspective. Biological propionate production is limited by high downstream purification costs which can be addressed if the target yield, productivity and titre can be achieved. Genome shuffling combined with high throughput omics and metabolic engineering is providing new opportunities, and biological propionate production is likely to enter the market in the not so distant future. In order to realise the full potential of metabolic engineering and heterologous expression, however, a greater understanding of metabolic capabilities of the native producers, the fittest producers, is required.

  12. Acid dip for dosemeter

    International Nuclear Information System (INIS)

    Stewart, J.C.; McWhan, A.F.

    1982-01-01

    Background signal in a PTFE based dosemeter caused by impurities in the PTFE and in the active component such as lithium fluoride is substantially reduced by treating the dosemeter with acid. The optimum treatment involves use of hydrofluoric acid at room temperature for approximately one minute, followed by thorough washing with methanol, and finally drying. This treatment is best applied after the original manufacture of the dosemeters. It may also be applied to existing dosemeters after they have been in use for some time. The treatment produces a permanent effect in reducing both the light induced signal and the non-light induced signal. The process may be applied to all types of dosemeter manufactured from PTFE or other plastics or resins which are able to resist brief exposure to acid. The treatment works particularly well with dosemeters based on PTFE and lithium fluoride. It is also applicable to dosemeters based on calcium sulphate, lithium borate and magnesium borate. Acids which may be used include hydrofluoric, hydrochloric, nitric, phosphoric and sulphuric. (author)

  13. Acid Ceramidase in Melanoma

    DEFF Research Database (Denmark)

    Realini, Natalia; Palese, Francesca; Pizzirani, Daniela

    2016-01-01

    Acid ceramidase (AC) is a lysosomal cysteine amidase that controls sphingolipid signaling by lowering the levels of ceramides and concomitantly increasing those of sphingosine and its bioactive metabolite, sphingosine 1-phosphate. In the present study, we evaluated the role of AC-regulated sphing...

  14. Nucleic acids in circulation

    Indian Academy of Sciences (India)

    Elevated blood levels of extracellular nucleic acids have been reported in various disease conditions; such as ageing and age-related degenerative disorders, cancer; acute and chronic inflammatory conditions, severe trauma and autoimmune disorders. In addition to genomic DNA and nucleosomes, mitochondrial DNA is ...

  15. Salicylic Acid Topical

    Science.gov (United States)

    ... the package label for more information.Apply a small amount of the salicylic acid product to one or two small areas you want to treat for 3 days ... know that children and teenagers who have chicken pox or the flu should not use topical salicylic ...

  16. Acid Rain: Science Projects.

    Science.gov (United States)

    Stubbs, Harriett S.

    1989-01-01

    Presented is a science activity designed to help students monitor the pH of rainfall. Materials, procedures and follow-up activities are listed. A list of domestic and foreign sources of information is provided. Topics which relate to acid precipitation are outlined. (CW)

  17. Hyaluronic Acid Assays

    DEFF Research Database (Denmark)

    Itenov, Theis S; Kirkby, Nikolai S; Bestle, Morten H

    2015-01-01

    BACKGROUD: Hyaluronic acid (HA) is proposed as a marker of functional liver capacity. The aim of the present study was to compare a new turbidimetric assay for measuring HA with the current standard method. METHODS: HA was measured by a particle-enhanced turbidimetric immunoassay (PETIA) and enzyme...

  18. Multifunctional Cinnamic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Aikaterini Peperidou

    2017-07-01

    Full Text Available Our research to discover potential new multitarget agents led to the synthesis of 10 novel derivatives of cinnamic acids and propranolol, atenolol, 1-adamantanol, naphth-1-ol, and (benzylamino ethan-1-ol. The synthesized molecules were evaluated as trypsin, lipoxygenase and lipid peroxidation inhibitors and for their cytotoxicity. Compound 2b derived from phenoxyphenyl cinnamic acid and propranolol showed the highest lipoxygenase (LOX inhibition (IC50 = 6 μΜ and antiproteolytic activity (IC50 = 0.425 μΜ. The conjugate 1a of simple cinnamic acid with propranolol showed the higher antiproteolytic activity (IC50 = 0.315 μΜ and good LOX inhibitory activity (IC50 = 66 μΜ. Compounds 3a and 3b, derived from methoxylated caffeic acid present a promising combination of in vitro inhibitory and antioxidative activities. The S isomer of 2b also presented an interesting multitarget biological profile in vitro. Molecular docking studies point to the fact that the theoretical results for LOX-inhibitor binding are identical to those from preliminary in vitro study.

  19. Accidents with sulfuric acid

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2006-01-01

    Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

  20. Pantothenic acid and biotin

    Science.gov (United States)

    Pantothenic acid and biotin are types of B vitamins. They are water-soluble, which means that the body can't store them. If the body can't use all of the vitamin, the extra vitamins leave the body through the ...

  1. and amino acids

    Indian Academy of Sciences (India)

    Unknown

    P RABINDRA REDDY* and A MOHAN REDDY. Department of ... The mixed ligand complexes of Cu(II), Ni(II) and Co(II) with uridine and amino acids ..... Sabat M, Satyashur K A and Sundaralingam M 1983 J. Am. Chem. Soc. ... Uemura T, Shimura T, Nakamishi H, Tomahiro T, Nagawa Y and Okuno (Yohmei) H 1991. Inorg.

  2. Lactic acid and lactates

    NARCIS (Netherlands)

    Schreurs, V.V.A.M.

    2010-01-01

    This review aims to integrate the present state of knowledge on lactate metabolism in human and mammalian physiology as far as it could be subject to nutritional interventions. An integrated view on the nutritional, metabolic and physiological aspects of lactic acid and lactates might open a

  3. Origin of fatty acids

    International Nuclear Information System (INIS)

    Prieur, B.E.

    1995-01-01

    The appearance of fatty acids and membranes is one of the most important events of the prebiotic world because genesis of life required the compartmentalization of molecules. Membranes allowed cells to become enriched with molecules relevant for their evolution and gave rise to gradients convertible into energy. By virtue of their hydrophobic/hydrophilic interface, membranes developed certain enzymatic activities impossible in the aqueous phase. A prebiotic cell is an energy unit but it is also an information unit. It has a past, a present and a future. The biochemistry of fatty acids involves acetylCoA, malonylCoA and an enzyme, acyl synthetase, which joins both molecules. After substitution of the acetyl group in place of the carboxyl group of malonyl derivatives, the chain is reduced and dehydrated to crotonyl derivatives. These molecules can again react with malonylCoA to form unsaturated chain; they can also undergo a new reduction step to form butyryl derivatives which can react with malonylCoA to form a longer aliphatic chain. The formation of malonylCoA consumes ATP. The reduction step needs NADPH and proton. Dehydration requires structural information because the reduction product is chiral (D configuration). It is unlikely that these steps were possible in a prebiotic environment. Thus we have to understand how fatty acids could appear in the prebiotic era. This hypothesis about the origin of fatty acids is based on the chemistry of sulfonium ylides and sulfonium salts. The most well-known among these molecules are S-melthyl-methionine and S-adenosyl methionine. The simplest sulfonium cation is the trimethylsulfonium cation. Chemists have evidence that these products can produce olefin when they are heated or flashed with UV light in some conditions. I suggest that these volatile products can allow the formation of fatty acids chains in atmospheric phase with UV and temperature using methanol as starting material. Different synthetic pathways will be

  4. Fatty acid-producing hosts

    Science.gov (United States)

    Pfleger, Brian F; Lennen, Rebecca M

    2013-12-31

    Described are hosts for overproducing a fatty acid product such as a fatty acid. The hosts include an exogenous nucleic acid encoding a thioesterase and, optionally, an exogenous nucleic acid encoding an acetyl-CoA carboxylase, wherein an acyl-CoA synthetase in the hosts are functionally delected. The hosts prefereably include the nucleic acid encoding the thioesterase at an intermediate copy number. The hosts are preferably recominantly stable and growth-competent at 37.degree. C. Methods of producing a fatty acid product comprising culturing such hosts at 37.degree. C. are also described.

  5. Acetic acid extraction from aqueous solutions using fatty acids

    NARCIS (Netherlands)

    IJmker, H.M.; Gramblicka, M.; Kersten, Sascha R.A.; van der Ham, Aloysius G.J.; Schuur, Boelo

    2014-01-01

    A major challenge for production of acetic acid via bio-based routes is cost-effective concentration and purification of the acetic acid from the aqueous solutions, for which liquid–liquid extraction is a possible method. A main challenge in extraction of acetic acid from dilute aqueous solutions is

  6. College Chemistry Students' Mental Models of Acids and Acid Strength

    Science.gov (United States)

    McClary, LaKeisha; Talanquer, Vicente

    2011-01-01

    The central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research…

  7. Cytotoxic effect of betulinic acid and betulinic acid acetate isolated ...

    African Journals Online (AJOL)

    Cytotoxic effect of betulinic acid and betulinic acid acetate isolated from Melaleuca cajuput on human myeloid leukemia (HL-60) cell line. ... The cytotoxic effect of betulinic acid (BA), isolated from Melaleuca cajuput a Malaysian plant and its four synthetic derivatives were tested for their cytotoxicity in various cell line or ...

  8. Industrial ecotoxicology "acid rain".

    Science.gov (United States)

    Astolfi, E; Gotelli, C; Higa, J

    1986-01-01

    The acid rain phenomenon was studied in the province of Cordoba, Argentina. This study, based on a previously outlined framework, determined the anthropogenic origin of the low pH due to the presence of industrial hydrochloric acid wastage. This industrial ecotoxicological phenomenon seriously affected the forest wealth, causing a great defoliation of trees and shrubs, with a lower effect on crops. A survey on its effects on human beings has not been carried out, but considering the corrosion caused to different metals and its denouncing biocide effect on plants and animals, we should expect to find some kind of harm to the health of the workers involved or others engaged in farming, and even to those who are far away from the polluting agent.

  9. Radioimmunoassay for jasmonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Knoefel, H.D.; Brueckner, C.; Kramell, R.; Sembdner, G.; Schreiber, K. (Akademie der Wissenschaften der DDR, Halle/Saale. Inst. fuer Biochemie der Pflanzen)

    1984-01-01

    A radioimmunoassay (RIA) for the natural plant growth regulator jasmonic acid (JA) was developed. The antiserum was raised in rabbits against (+-)-JA linked to bovine serum albumin. As tracer tritium labelled (+-)-JA (spec. act. 7.4 x 10/sup 9/ Bq x mmol/sup -1/) was used. Cross-reactivity studies with compounds structurally related to JA demonstrated the antiserum to be specific for JA, abscisic acid normally present in the same extract does not interfer. The RIA has a detection limit of 2 ng (-)-JA methylester, a measuring range 2-200 ng, and no extensive purification is required prior to estimation. Therefore, in JA analysis the RIA described is superior to GC, HPLC, and bioassay. This new method has been employed for studies on the distribution of JA in different plant organs of the broad bean, Vicia faba L.

  10. Acid corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Chen, N G

    1964-04-28

    An acid corrosion inhibitor is prepared by a 2-stage vacuum evaporation of effluents obtained from the ammonia columns of the coking oven plant. The effluent, leaving a scrubber in which the phenols are removed at a temperature of 98$C, passes through a quartz filter and flows into a heated chamber in which it is used for preheating a solution circulating through a vacuum unit, maintaining the temperature of the solution at 55$ to 60$C. The effluent enters a large tank in which it is boiled at 55$ to 60$C under 635 to 640 mm Hg pressure. Double evaporation of this solution yields a very effective acid corrosion inhibitor. Its corrosion-preventing effect is 97.9% compared with 90.1% for thiourea and 88.5% for urotropin under identical conditions.

  11. N-(3-Methylphenylsuccinamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-02-01

    Full Text Available In the crystal structure of the title compound, C11H13NO3, the conformations of the N—H and C=O bonds in the amide segment are anti to each other, and that of the amide H atom is anti to the meta-methyl group in the benzene ring. Furthermore, the conformations of the amide oxygen and the carbonyl O atom of the acid segment are also anti to the adjacent –CH2 groups. The C=O and O—H bonds of the acid group are syn to each other. In the crystal, the molecules are packed into infinite chains through intermolecular N—H...O and O—H...O hydrogen bonds.

  12. N-(3-Chlorophenylmaleamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-07-01

    Full Text Available In the title compound, C10H8ClNO3, the molecular conformation is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond within the maleamic acid unit and the second is a C—H...O hydrogen bond which connects the amide group with the phenyl ring. The maleamic acid unit is essentially planar, with an r.m.s. deviation of 0.044 Å, and makes a dihedral angle of 15.2 (1° with the phenyl ring. In the crystal, intermolecular N—H...O hydrogen bonds link the molecules into C(7 chains running [010].

  13. Mortar fights acid corrosion

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-14

    The burning of coal or oil to produce heat required to operate a power boiler also generates a severe corrosion problem within the interior of the duct and stacks used to emit the flue gas into the atmosphere. How can concrete and steel be protected from the effects of acid attack, when the acids are carried in a gas form, or come into direct contact with the steel or concrete from spillage or immersion conditions. Industry in North America has found that the solution to this problem is to build an outside concrete column, in this case of Portland cement, and inside that column, build a totally independent brick liner bonded with Sauereisen mortar.

  14. (Radioiodinated free fatty acids)

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Jr., F. F.

    1987-12-11

    The traveler participated in the Second International Workshop on Radioiodinated Free Fatty Acids in Amsterdam, The Netherlands where he presented an invited paper describing the pioneering work at the Oak Ridge National Laboratory (ORNL) involving the design, development and testing of new radioiodinated methyl-branched fatty acids for evaluation of heart disease. He also chaired a technical session on the testing of new agents in various in vitro and in vivo systems. He also visited the Institute for Clinical and Experimental Nuclear Medicine in Bonn, West Germany, to review, discuss, plan and coordinate collaborative investigations with that institution. In addition, he visited the Cyclotron Research Center in Liege, Belgium, to discuss continuing collaborative studies with the Osmium-191/Iridium-191m radionuclide generator system, and to complete manuscripts and plan future studies.

  15. Acidity of Scandinavian precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, E; Bordin, G

    1955-01-01

    Data on the pH of the total monthly precipitation at stations of a Swedish network for sampling and chemical analysis of precipitation and atmospheric aerosols during the year July 1953 to June 1954 are presented and discussed, together with the pH data from the first two months of operation of a large pan-Scandinavian net. It is found that well-defined regions of acidity and alkalinity relative to the pH of water in equilibrium with atmospheric carbon dioxide exist, and that these regions persist to such an extent that the monthly deviations from the pattern of the annual mean pH at stations unaffected by local pollution show persistently high acidity, while inland northern stations show equally persistent alkalinity. Some possible reasons for the observed distributions are considered.

  16. Omega-3 fatty acids (image)

    Science.gov (United States)

    Omega-3 fatty acids are a form of polyunsaturated fat that the body derives from food. Omega-3s (and omega-6s) are known as essential fatty acids (EFAs) because they are important for good health. ...

  17. Bile acids for viral hepatitis

    DEFF Research Database (Denmark)

    Chen, Weikeng; Liu, J; Gluud, C

    2007-01-01

    Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness.......Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness....

  18. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Sundin, Peter; Wesén, Clas

    1997-01-01

    Halogenated fatty acids are the major contributors to organohalogen compounds in lipids of marine mammals, fish, and bivalves. For the initial characterization of these recently noticed compounds, a determination of the halogen concentration has usually been combined with some lipid isolation......), atomic emission spectrometry, and mass spectrometry. For most environmental samples, chlorinated FAMEs must be enriched prior to GC. ELCD is a useful detection method for indicating halogenated FAMEs in the chromatograms, and tentative identification of the halogenated species can be obtained...

  19. Accidents with sulfuric acid

    OpenAIRE

    Rajković Miloš B.

    2006-01-01

    Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eigh...

  20. Sources of atmospheric acidity

    International Nuclear Information System (INIS)

    Clarke, A.G.

    1992-01-01

    The emissions of acid gases from anthropogenic sources and their impact on the environment are the main concern of this book. However, that impact can only be assessed if all the naturally occurring sources of these gases are also known and can be quantified. Given the widely dispersed nature of the natural sources and the problems of measurement of trace species at low concentrations, often in remote regions, the quantification is a very difficult task. Nevertheless, considerable progress has been made over the last decade. In this chapter both man-made and natural sources of atmospheric acidity will be reviewed, but the emphasis will be placed not so much on the global balances as on the scale of the natural sources in relation to the man-made sources. This requires that the very uneven geographical distribution of emissions and the lifetime of individual chemical species be taken into account. The emissions considered are sulphur compounds, nitrogen compounds, chlorine compounds and organic acids. The anthropogenic sources discussed are the combustion of fossil fuels and certain industrial processes. Emissions data for anthropogenic sources are given for the United Kingdom, Europe, USA and globally. A list of 95 references is given. (Author)

  1. Whence the acid raindrop

    International Nuclear Information System (INIS)

    Heaton, T.H.E.

    1987-01-01

    Absorption of NO 2 can cause damage in animals and plants and, if present trends for NO x emissions continue, their by-product nitric acid may soon overtake sulphuric acid as the main acidifying agent of 'acid' rain. In response to this problem the feasibility of reducing NO x emissions from power stations is being studied. Although there can be no doubt that these expensive controls are desirable, their benefits are difficult to predict for two reasons: NO x is not only emitted by fuel combustion and the degree to which an industrialised country benefits from the implementation of NO x emission controls depends on how much its pollutant 'fall out' is immediately returned from the atmosphere, and how much is exported to neighbouring countries. The above factors involve questions regarding the source and reaction mechanisms for nitrogen compounds in the atmosphere. Because stable isotope ratio analysis has proved to be of value in providing answers to such questions in other environments, an investigation of the 15 N/ 14 N ratios of atmospheric gases (NO x , NH 3 ) and their solution products in rain (NO 3 , NH + 4 ) seemed to be justified

  2. Hepatic Toxicity of Perfluorocarboxylic Acids.

    Science.gov (United States)

    1996-07-01

    1995). 3. N. V. Reo, C. M. Goecke, L. Narayanan, and B. M. Jarnot. "Effects of Perfluoro-n-octanoic Acid , Perfluoro-n-decanoic Acid , and Clofibrate ...Artz, and B. M. Jarnot: "ILiver Phosphorous Metabolic Response to Perfluorocarboxylic Acids and Clofibrate in Rats and Guinea Pigs: A 31 P NMR Study...Peroxisome Induction by Perfluoro-n-decanoic Acid and Clofibrate in the Rat: Proliferation Versus Activity." International Society for the Study of

  3. Acids and bases solvent effects on acid-base strenght

    CERN Document Server

    Cox, Brian G

    2013-01-01

    Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

  4. Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

    Science.gov (United States)

    Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

    2002-12-06

    Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

  5. Molecular Structure of Nucleic Acids

    Indian Academy of Sciences (India)

    Molecular Structure of Nucleic Acids. A Structure for Deoxyribose Nucleic Acid. J. D. Watson and F. H. C. Crick. Medical Research Council Unit for the Study of the Molecular Structure of Biological. Systems, Cavendish Laboratory, Cambridge. April 2. We wish to suggest a structure for the salt of deoxyribose nucleic acid ...

  6. Fumaric acid production by fermentation

    NARCIS (Netherlands)

    Roa Engel, C.A.; Straathof, A.J.J.; Zijlmans, T.W.; Van Gulik, W.M.; Van der Wielen, L.A.M.

    2008-01-01

    Abstract The potential of fumaric acid as a raw material in the polymer industry and the increment of cost of petroleum-based fumaric acid raises interest in fermentation processes for production of this compound from renewable resources. Although the chemical process yields 112% w/w fumaric acid

  7. Pantothenic acid biosynthesis in zymomonas

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  8. Uptake of BSH in M2R melanoma cells monitored by NMR spectroscopy

    International Nuclear Information System (INIS)

    Koudinova, N.; Elhanati, G.; Salomon, Y.; Bendel, P.

    2000-01-01

    The accumulation ratio of BSH, relative to that of boric acid, in M2R mouse melanoma cells, was measured using 11 B NMR of the cell extracts. The cells were incubated in growth medium for up to 24 h, in the presence of 0.8 mM boric acid and 0.25-1.5 mM BSH. The aqueous phase of the cellular extracts was re-suspended for NMR spectroscopy. The relative accumulation ratio of BSH/boric acid determined from 9 separate experiments was 0.45±0.09. (author)

  9. Danburite decomposition by hydrochloric acid

    International Nuclear Information System (INIS)

    Mamatov, E.D.; Ashurov, N.A.; Mirsaidov, U.

    2011-01-01

    Present article is devoted to decomposition of danburite of Ak-Arkhar Deposit of Tajikistan by hydrochloric acid. The interaction of boron containing ores of Ak-Arkhar Deposit of Tajikistan with mineral acids, including hydrochloric acid was studied. The optimal conditions of extraction of valuable components from danburite composition were determined. The chemical composition of danburite of Ak-Arkhar Deposit was determined as well. The kinetics of decomposition of calcined danburite by hydrochloric acid was studied. The apparent activation energy of the process of danburite decomposition by hydrochloric acid was calculated.

  10. Waste acid detoxification and reclamation

    International Nuclear Information System (INIS)

    Brouns, T.M.; Stewart, T.L.

    1988-01-01

    Economically feasible processes that reduce the volume, quantity, and toxicity of metal-bearing waste acids by reclaiming, reusing, and recycling spent acids and metal salts are being developed and demonstrated. The acids used in the demonstrations are generated during metal-finishing operations used in nuclear fuel fabrication; HF-HNO 3 , HNO 3 , and HNO 3 -H 2 SO 4 wastes result from Zr etching, Cu stripping, and chemical milling of U. At discharge, wastes contain high concentrations of acid and one major metal impurity. The waste minimization process used to reclaim acid from these three streams incorporates three processes for acid regeneration and reclamation. Normally, HNO 3 remains in the bottoms when an aqueous acid solution is distilled; however, in the presence of H 2 SO 4 , HNO 3 will distill to the overhead stream. In this process, nitrates and fluorides present as free acid and metal salts can be reclaimed as acid for recycle to the metal-finishing processes. Uranium present in the chemical milling solution can be economically recovered from distillation bottoms and refined. Using acid distillation, the volume of chemical milling solution discharged as waste can be reduced by as much as 60% depending on the H 2 SO 4 concentration. A payback period of 2.2 years has been estimated for this process. The development and demonstration of precipitation and distillation processes for detoxification and reclamation of waste acid is supported by the US Department of Energy's Hazardous Waste Remedial Actions Program (HAZWRAP)

  11. New Acid Combination for a Successful Sandstone Acidizing

    Science.gov (United States)

    Shafiq, M. U.; Mahmud, H. K. B.; Rezaee, R.

    2017-05-01

    With the development of new enhanced oil recovery techniques, sandstone acidizing has been introduced and played a pivotal role in the petroleum industry. Different acid combinations have been applied, which react with the formation, dissolve the soluble particles; thus increase the production of hydrocarbons. To solve the problems which occurred using current preflush sandstone acidizing technology (hydrochloric acid); a new acid combination has been developed. Core flooding experiments on sandstone core samples with dimensions 1.5 in. × 3 in. were conducted at a flow rate of 2 cm3/min. A series of hydrochloric-acetic acid mixtures with different ratios were tested under 150°F temperature. The core flooding experiments performed are aimed to dissolve carbonate, sodium, potassium and calcium particles from the core samples. These experiments are followed by few important tests which include, porosity-permeability, pH value, Inductively Coupled Plasma (ICP) analysis and Nuclear Magnetic Resonance (NMR measurements). All the results are compared with the results of conventional hydrochloric acid technology. NMR and porosity analysis concluded that the new acid combination is more effective in creating fresh pore spaces and thus increasing the reservoir permeability. It can be seen from the pore distribution before and after the acidizing. Prior applying acid; the large size of pores appears most frequently in the pore distribution while with the applied acid, it was found that the small pore size is most the predominant of the pore distribution. These results are validated using ICP analysis which shows the effective removal of calcium and other positive ions from the core sample. This study concludes that the combination of acetic-hydrochloric acid can be a potential candidate for the preflush stage of sandstone acidizing at high temperature reservoirs.

  12. Urban acid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Conlan, D.E.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E.

    1991-07-01

    In this document results from the Greater Manchester Acid Deposition Survey (GMADS), an urban precipitation chemistry network, for 1990 are presented. Full analytical methods are described along with the precision and accuracy of the methods used. The spatial variability of precipitation chemistry and deposition over this urban region was investigated using a network of twenty collectors. Concentrations of non marine sulphate, ammonium, calcium and hydrogen, and nitrogen dioxide gas concentrations all show significant spatial variability. The spatial variability of the deposition rates of non marine sulphate, nitrate, ammonium, hydrogen and calcium were significant. (Author).

  13. Synthesis of aminoaldonic acids

    DEFF Research Database (Denmark)

    Jørgensen, Christel Thea

    With the aim of synthesising aminoaldonic acids, two 2-acetamido-2-deoxyaldonolactones with D-galacto (6) and D-arabino (11) configuration were prepared from acetylated sugar formazans in analogy with a known procedure. Empolying the same procedure to acetylated sugar phenylhydrazones gave mixtures...... and 82, respectively. The aminolactone 84 was converted into the corresponding amino sugar 89.With the aim of synthesising substrates for the Pictet-Spengler reaction three 4-aldehydo acetamidodideoxytetronolactones 92, 97 and 103 were prepared by periodate cleavage of the corresponding hexonolactones...

  14. Folic Acid: MedlinePlus Health Topic

    Science.gov (United States)

    ... acid in diet (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Folic Acid updates ... acid - test Folic acid in diet Related Health Topics Vitamins National Institutes of Health The primary NIH ...

  15. Solid acid catalysis from fundamentals to applications

    CERN Document Server

    Hattori, Hideshi

    2014-01-01

    IntroductionTypes of solid acid catalystsAdvantages of solid acid catalysts Historical overviews of solid acid catalystsFuture outlookSolid Acids CatalysisDefinition of acid and base -Brnsted acid and Lewis acid-Acid sites on surfacesAcid strengthRole of acid sites in catalysisBifunctional catalysisPore size effect on catalysis -shape selectivity-Characterization of Solid Acid Catalysts Indicator methodTemperature programmed desorption (TPD) of ammoniaCalorimetry of adsorption of basic moleculesInfrare

  16. Uracil in formic acid hydrolysates of deoxyribonucleic acid

    Science.gov (United States)

    Schein, Arnold H.

    1966-01-01

    1. When DNA is hydrolysed with formic acid for 30min. at 175° and the hydrolysate is chromatographed on paper with propan-2-ol–2n-hydrochloric acid, in addition to expected ultraviolet-absorbing spots corresponding to guanine, adenine, cytosine and thymine, an ultraviolet-absorbing region with RF similar to that of uracil can be detected. Uracil was separated from this region and identified by its spectra in acid and alkali, and by its RF in several solvent systems. 2. Cytosine, deoxyribocytidine and deoxyribocytidylic acid similarly treated with formic acid all yielded uracil, as did a mixture of deoxyribonucleotides. 3. Approx. 4% of deoxyribonucleotide cytosine was converted into uracil by the formic acid treatment. ImagesFig. 1. PMID:5949371

  17. Uric acid nephrolithiasis: An update.

    Science.gov (United States)

    Cicerello, Elisa

    2018-04-01

    Uric acid nephrolithiasis appears to increase in prevalence. While a relationship between uric acid stones and low urinary pH has been for long known, additional association with various metabolic conditions and pathophysiological basis has recently been elucidated. Some conditions such as diabetes and metabolic syndrome disease, excessive dietary intake, and increased endogenous uric acid production and/or defect in ammoniagenesis are associated with low urinary pH. In addition, the phenomenon of global warming could result in an increase in areas with greater climate risk for uric acid stone formation. There are three therapeutic steps to be taken for management of uric acid stones: identification of urinary pH profiles, assessment of urinary volume status, and identification of disorders leading to excessive uric acid production. However, the most important factor for uric acid stone formation is acid urinary pH, which is a prerequisite for uric acid precipitation. This article reviews recent insights into the pathophysiology of uric acid stones and their management.

  18. Bile Acid Metabolism and Signaling

    Science.gov (United States)

    Chiang, John Y. L.

    2015-01-01

    Bile acids are important physiological agents for intestinal nutrient absorption and biliary secretion of lipids, toxic metabolites, and xenobiotics. Bile acids also are signaling molecules and metabolic regulators that activate nuclear receptors and G protein-coupled receptor (GPCR) signaling to regulate hepatic lipid, glucose, and energy homeostasis and maintain metabolic homeostasis. Conversion of cholesterol to bile acids is critical for maintaining cholesterol homeostasis and preventing accumulation of cholesterol, triglycerides, and toxic metabolites, and injury in the liver and other organs. Enterohepatic circulation of bile acids from the liver to intestine and back to the liver plays a central role in nutrient absorption and distribution, and metabolic regulation and homeostasis. This physiological process is regulated by a complex membrane transport system in the liver and intestine regulated by nuclear receptors. Toxic bile acids may cause inflammation, apoptosis, and cell death. On the other hand, bile acid-activated nuclear and GPCR signaling protects against inflammation in liver, intestine, and macrophages. Disorders in bile acid metabolism cause cholestatic liver diseases, dyslipidemia, fatty liver diseases, cardiovascular diseases, and diabetes. Bile acids, bile acid derivatives, and bile acid sequestrants are therapeutic agents for treating chronic liver diseases, obesity, and diabetes in humans. PMID:23897684

  19. Electrolytic nature of aqueous sulfuric acid. 2. Acidity.

    Science.gov (United States)

    Fraenkel, Dan

    2012-09-27

    In part 1 of this study, I reported that the Debye-Hückel limiting law and the smaller-ion shell (SiS) model of strong electrolyte solutions fit nicely with the experimental mean ionic activity coefficient (γ(±)) of aqueous sulfuric acid as a function of concentration and of temperature when the acid is assumed to be a strong 1-3 electrolyte. Here, I report that the SiS-derived activity coefficient of H(+), γ(H(+)), of the 1-3 acid is comparable to that of aqueous HCl. This agrees with titration curves showing, as well-known, that sulfuric acid in water is parallel in strength to aqueous HCl. The calculated pH is in good accord with the Hammett acidity function, H(0), of aqueous sulfuric acid at low concentration, and differences between the two functions at high concentration are discussed and explained. This pH-H(0) relation is consistent with the literature showing that the H(0) of sulfuric acid (in the 1-9 M range) is similar to those of HCl and the other strong mineral monoprotic acids. The titration of aqueous sulfuric acid with NaOH does not agree with the known second dissociation constant of 0.010 23; rather, the constant is found to be ~0.32 and the acid behaves upon neutralization as a strong diprotic acid practically dissociating in one step. A plausible reaction pathway is offered to explain how the acid may transform, upon base neutralization, from a dissociated H(4)SO(5) (as 3H(+) and HSO(5)(3-)) to a dissociated H(2)SO(4) even though the equilibrium constant of the reaction H(+) + HSO(5)(3-) ↔ SO(4)(2-) + H(2)O, at 25 °C, is 10(-37) (part 1).

  20. Counter current extraction of phosphoric acid: Food grade acid production

    International Nuclear Information System (INIS)

    Shlewit, H.; AlIbrahim, M.

    2009-01-01

    Extraction, scrubbing and stripping of phosphoric acid from the Syrian wet-phosphoric acid was carried out using Micro-pilot plant of mixer settler type of 8 l/h capacity. Tributyl phosphate (TBP)/di-isopropyl ether (DIPE) in kerosene was used as extractant. Extraction and stripping equilibrium curves were evaluated. The number of extraction and stripping stages to achieve the convenient and feasible yield was determined. Detailed flow sheet was suggested for the proposed continuous process. Data obtained include useful information for the design of phosphoric acid extraction plant. The produced phosphoric acid was characterized using different analytical techniques. (author)

  1. Acidizing reservoirs while chelating iron with sulfosalicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, W A; Berkshire, D C

    1980-09-30

    A well treating process is described in which an aqueous solution of a strong acid capable of dissolving solids in a manner increasing the permeability of a subterranean earth formation is injected into a subterranean reservoir that contains an asphaltenic oil. At least the first injected portion of the aqueous acid and a solution or homogeneous dispersion of at least enough 5-sulfosalicylic acid to chelate with and prevent the formation of iron-asphaltene solids are included with substantially all of the ferric ions that become dissolved within the strong acid solution that enters the earth formation. 10 claims.

  2. Inhibition and Kinetic Studies of Tortoise (Kinixys erosa) Liver arginase

    African Journals Online (AJOL)

    The effect of amino acid on tortoise liver arginase showed that L-lysine, L-valine, L-serine, L-aspartic acid and L aspartic acid had significant inhibitory effect on the enzyme but proline and glutamic acid showed slight inhibition. Ethylenediaminetetraacetic acid (EDTA), citrate, ascorbic acid, boric acid and sodium borate ...

  3. Danburite decomposition by sulfuric acid

    International Nuclear Information System (INIS)

    Mirsaidov, U.; Mamatov, E.D.; Ashurov, N.A.

    2011-01-01

    Present article is devoted to decomposition of danburite of Ak-Arkhar Deposit of Tajikistan by sulfuric acid. The process of decomposition of danburite concentrate by sulfuric acid was studied. The chemical nature of decomposition process of boron containing ore was determined. The influence of temperature on the rate of extraction of boron and iron oxides was defined. The dependence of decomposition of boron and iron oxides on process duration, dosage of H 2 SO 4 , acid concentration and size of danburite particles was determined. The kinetics of danburite decomposition by sulfuric acid was studied as well. The apparent activation energy of the process of danburite decomposition by sulfuric acid was calculated. The flowsheet of danburite processing by sulfuric acid was elaborated.

  4. Recovering uranium from phosphoric acid

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Wet-process phosphoric acid contains a significant amount of uranium. This uranium totals more than 1,500 tons/yr in current U.S. acid output--and projections put the uranium level at 8,000 tons/yr in the year 2000. Since the phosphoric acid is a major raw material for fertilizers, uranium finds its way into those products and is effectively lost as a resource, while adding to the amount of radioactive material that can contaminate the food chain. So, resource-conservation and environmental considerations both make recovery of the uranium from phosphoric acid desirable. This paper describes the newly developed process for recovering uranium from phosphoric acid by using solvent-extraction technique. After many extractants had been tested, the researchers eventually selected the combination of di (2-ethylhexyl) phosphoric acid (DEPA) and trioctylphosphine oxide (TOPO) as the most suitable. The flowscheme of the process is included

  5. Acid mine drainage

    Science.gov (United States)

    Bigham, Jerry M.; Cravotta, Charles A.

    2016-01-01

    Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

  6. Dicarboxylic acids from electric discharge

    Science.gov (United States)

    Zeitman, B.; Chang, S.; Lawless, J. G.

    1974-01-01

    An investigation was conducted concerning the possible synthesis of a suite of dicarboxylic acids similar to that found in the Murchison meteorite. The investigation included the conduction of a chemical evolution experiment which simulated electric discharge through the primitive atmosphere of the earth. The suite of dicarboxylic acids obtained in the electric discharge experiment is similar to that of the Murchison meteorite, except for the fact that 2-chlorosuccinic acid is present in the spark discharge.

  7. Uranium extraction from phosphoric acid

    International Nuclear Information System (INIS)

    Araujo Figueiredo, C. de

    1984-01-01

    The recovery of uranium from phosphoric liquor by two extraction process is studied. First, uranium is reduced to tetravalent condition and is extracted by dioctypyrophosphoric acid. The re-extraction is made by concentrated phosphoric acid with an oxidizing agent. The re-extract is submitted to the second process and uranium is extracted by di-ethylhexilphosphoric acid and trioctylphosphine oxide. (M.A.C.) [pt

  8. Acid precipitation literature review

    Energy Technology Data Exchange (ETDEWEB)

    Seip, H M; Andersen, B; Andersson, G; Hov, Oe; Kucera, V; Moseholm, L

    1986-01-01

    There is an increasing number of publications on acid deposition and related phenomena. Interest in these topics has also been reflected in a considerable number of meetings and conferences in this field. The largest of these in 1985 was the ''International Symposium on Acidic Precipitation'' (Muskoka, Ontario). Most work so far has been carried out in North America and Europe. There is, however, an increasing interest in obtaining a better picture of sensitive areas and possible acidification in other parts of the world. Anthropogenic SO/sub 2/ emissions have been estimated to be (in TgSyr/sup -1/): 2.4 (Africa), 4.1 (South America), 0.7 (Ocenia), and 18.3 (Asia). The largest increase during the last decade has been in Asia. Based on Studies of precipitation in remote areas it has been suggested that the natural background concentration for sulphate in many areas should be about 6 ..mu..eq 1/sup -1/. A new study of sulphate and nitrate in Greenland snow showed that both ions increased by a factor of about 2 from 1895 to 1978. The concentrations of SO/sub 2/ at Norwegian rural sites show a decreasing trend since late 1970s, while concentrations of sulphate in air show no clear trend. More reliable models for transformation, transport and deposition of chemicals are being developed, including three-dimensional grid models to describe episodes of elevated pollution levels lasting for a few days. Model calculations indicate that control of hydrocarbon (HC) emissions is much more efficient in reducing the ozone level in southern Scandinavia in episodes influenced by long-range transported pollutants than NO/sub x/ control of combined NO/sub x/ and HC control. 36 refs. (EG).

  9. A radioimmunoassay for abscisic acid

    International Nuclear Information System (INIS)

    Walton, D.; Dashek, W.; Galson, E.

    1979-01-01

    We have developed a radioimmunoassay (RIA) for abscisic acid (ABA) in the 0.1 ng to 2.5 ng range. Antibodies were obtained from rabbits immunized with ABA bound via its carboxyl group to bovine serum albumin. Cross-reactivity studies indicate that ABA esters are completely cross-reactive with ABA, while trans, trans abscisic acid (t-ABA) phaseic acid (PA) and dihydrophaseic acid (DPA) have much lower but significant cross-reactivities. Purification methods which reduce the levels of cross-reacting substances are described. (orig.) 891 AJ/orig. 892 MKO [de

  10. Acid digestion of organic materials

    International Nuclear Information System (INIS)

    Capp, P.D.

    1988-01-01

    To overcome the high temperatures involved in straight incineration of organic waste and the difficulty of extracting actinides from the ash various research establishments throughout the world, including Winfrith and Harwell in the UK, have carried out studies on an alternative chemical combustion method known as acid digestion. The basis of the technique is to digest the waste in concentrated sulphuric acid containing a few percent of nitric acid at a temperature of about 250 0 C. Acid digestion residues consist mainly of non-refractory inorganic sulphates and oxides from which any actinide materials can easily be extracted. (author)

  11. [Fatty acids in confectionery products].

    Science.gov (United States)

    Daniewski, M; Mielniczuk, E; Jacórzyński, B; Pawlicka, M; Balas, J; Filipek, A; Górnicka, M

    2000-01-01

    The content of fat and fatty acids in 144 different confectionery products purchased on the market in Warsaw region during 1997-1999 have been investigated. In examined confectionery products considerable variability of both fat and fatty acids content have been found. The content of fat varied from 6.6% (coconut cookies) up to 40% (chocolate wafers). Saturated fatty acids were present in both cis and trans form. Especially trans fatty acids reach (above 50%) were fats extracted from nut wafers, coconuts wafers.

  12. Preparation and characterization Al3+-bentonite Turen Malang for esterification fatty acid (palmitic acid, oleic acid and linoleic acid)

    Science.gov (United States)

    Abdulloh, Abdulloh; Aminah, Nanik Siti; Triyono, Mudasir, Trisunaryanti, Wega

    2016-03-01

    Catalyst preparation and characterization of Al3+-bentonite for esterification of palmitic acid, oleic acid and linoleic acid has been done. Al3+-bentonite catalyst was prepared from natural bentonite of Turen Malang through cation exchange reaction using AlCl3 solution. The catalysts obtained were characterized by XRD, XRF, pyridine-FTIR and surface area analyser using the BET method. Catalyst activity test of Al3+-bentonite for esterification reaction was done at 65°C using molar ratio of metanol-fatty acid of 30:1 and 0.25 g of Al3+-bentonite catalyst for the period of ½, 1, 2, 3, 4 and 5 hours. Based on the characterization results, the Al3+-bentonite Turen Malang catalyst has a d-spacing of 15.63 Ǻ, acid sites of Brönsted and Lewis respectively of 230.79 µmol/g and 99.39 µmol/g, surface area of 507.3 m2/g and the average of radius pore of 20.09 Å. GC-MS analysis results of the oil phase after esterification reaction showed the formation of biodiesel (FAME: Fatty acid methyl ester), namely methyl palmitate, methyl oleate and methyl linoleate. The number of conversions resulted in esterification reaction using Al3+-bentonite Turen Malang catalyst was 74.61%, 37.75%, and 20, 93% for the esterification of palmitic acid, oleic acid and linoleic acid respectively.

  13. Zirconium for nitric acid solutions

    International Nuclear Information System (INIS)

    Yau, T.L.

    1984-01-01

    The excellent corrosion resistance of zirconium in nitric acid has been known for over 30 years. Recently, there is an increasing interest in using zirconium for nitric acid services. Therefore, an extensive research effort has been carried out to achieve a better understanding of the corrosion properties of zirconium in nitric acid. Particular attention is paid to the effect of concentration, temperature, structure, solution impurities, and stress. Immersion, autoclave, U-bend, and constant strain-rate tests were used in this study. Results of this study indicate that the corrosion resistance of zirconium in nitric acid is little affected by changes in temperature and concentration, and the presence of common impurities such as seawater, sodium chloride, ferric chloride, iron, and stainless steel. Moreover, the presence of seawater, sodium chloride, ferric chloride, and stainless steel has little effect on the stress corrosion craking (SCC) susceptibility of zirconium in 70% nitric acid at room temperatures. However, zirconium could be attacked by fluoride-containing nitric acid and the vapors of chloride-containing nitric acid. Also, high sustained tensile stresses should be avoided when zirconium is used to handle 70% nitric acid at elevated temperatures or > 70% nitric acid

  14. Valproic Acid Induced Hyperammonaemic Encephalopathy

    International Nuclear Information System (INIS)

    Amanat, S.; Shahbaz, N.; Hassan, Y.

    2013-01-01

    Objective: To observe clinical and laboratory features of valproic acid-induced hyperammonaemic encephalopathy in patients taking valproic acid. Methods: Observational study was conducted at the Neurology Department, Dow University of Health Sciences, Civil Hospital, Karachi, from February 26, 2010 to March 20, 2011. Ten patients on valproic acid therapy of any age group with idiopathic or secondary epilepsy, who presented with encephalopathic symptoms, were registered and followed up during the study. Serum ammonia level, serum valproic acid level, liver function test, cerebrospinal fluid examination, electroencephalogram and brain imaging of all the patients were done. Other causes of encephalopathy were excluded after clinical and appropriate laboratory investigations. Microsoft Excel 2007 was used for statistical analysis. Results: Hyperammonaemia was found in all patients with encephalopathic symptoms. Rise in serum ammonia was independent of dose and serum level of valproic acid. Liver function was also found to be normal in 80% (n=8) of the patients. Valproic acid was withdrawn in all patients. Three (30%) patients improved only after the withdrawal of valproic acid. Six (60%) patients improved after L-Carnitine replacement, one (10%) after sodium benzoate. On followup, serum ammonia had reduced to normal in five (50%) patients and to more than half of the baseline level in two (20%) patients. Three (30%) patients were lost to followup after complete clinical improvement. Conclusion: Within therapeutic dose and serum levels, valproic acid can cause symptomatic hyperammonaemia resulting in encephalopathy. All patients taking valproic acid presenting with encephalopathic symptoms must be monitored for the condition. (author)

  15. ACETIC ACID AND A BUFFER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  16. Thermal decomposition of gaseous ammonium nitrate at low pressure: kinetic modeling of product formation and heterogeneous decomposition of nitric acid.

    Science.gov (United States)

    Park, J; Lin, M C

    2009-12-03

    The thermal decomposition of ammonium nitrate, NH(4)NO(3) (AN), in the gas phase has been studied at 423-56 K by pyrolysis/mass spectrometry under low-pressure conditions using a Saalfeld reactor coated with boric acid. The sublimation of NH(4)NO(3) at 423 K was proposed to produce equal amounts of NH(3) and HNO(3), followed by the decomposition reaction of HNO(3), HNO(3) + M --> OH + NO(2) + M (where M = third-body and reactor surface). The absolute yields of N(2), N(2)O, H(2)O, and NH(3), which can be unambiguously measured and quantitatively calibrated under a constant pressure at 5-6.2 torr He are kinetically modeled using the detailed [H,N,O]-mechanism established earlier for the simulation of NH(3)-NO(2) (Park, J.; Lin, M. C. Technologies and Combustion for a Clean Environment. Proc. 4th Int. Conf. 1997, 34-1, 1-5) and ADN decomposition reactions (Park, J.; Chakraborty, D.; Lin, M. C. Proc. Combust. Inst. 1998, 27, 2351-2357). Since the homogeneous decomposition reaction of HNO(3) itself was found to be too slow to account for the consumption of reactants and the formation of products, we also introduced the heterogeneous decomposition of HNO(3) in our kinetic modeling. The heterogeneous decomposition rate of HNO(3), HNO(3) + (B(2)O(3)/SiO(2)) --> OH + NO(2) + (B(2)O(3)/SiO(2)), was determined by varying its rate to match the modeled result to the measured concentrations of NH(3) and H(2)O; the rate could be represented by k(2b) = 7.91 x 10(7) exp(-12 600/T) s(-1), which appears to be consistent with those reported by Johnston and co-workers (Johnston, H. S.; Foering, L.; Tao, Y.-S.; Messerly, G. H. J. Am. Chem. Soc. 1951, 73, 2319-2321) for HNO(3) decomposition on glass reactors at higher temperatures. Notably, the concentration profiles of all species measured could be satisfactorily predicted by the existing [H,N,O]-mechanism with the heterogeneous initiation process.

  17. Thermal Decomposition of Gaseous Ammonium Nitrate at Low Pressure: Kinetic Modeling of Product Formation and Heterogeneous Decomposition of Nitric Acid

    Science.gov (United States)

    Park, J.; Lin, M. C.

    2009-10-01

    The thermal decomposition of ammonium nitrate, NH4NO3 (AN), in the gas phase has been studied at 423-56 K by pyrolysis/mass spectrometry under low-pressure conditions using a Saalfeld reactor coated with boric acid. The sublimation of NH4NO3 at 423 K was proposed to produce equal amounts of NH3 and HNO3, followed by the decomposition reaction of HNO3, HNO3 + M → OH + NO2 + M (where M = third-body and reactor surface). The absolute yields of N2, N2O, H2O, and NH3, which can be unambiguously measured and quantitatively calibrated under a constant pressure at 5-6.2 torr He are kinetically modeled using the detailed [H,N,O]-mechanism established earlier for the simulation of NH3-NO2 (Park, J.; Lin, M. C. Technologies and Combustion for a Clean Environment. Proc. 4th Int. Conf. 1997, 34-1, 1-5) and ADN decomposition reactions (Park, J.; Chakraborty, D.; Lin, M. C. Proc. Combust. Inst. 1998, 27, 2351-2357). Since the homogeneous decomposition reaction of HNO3 itself was found to be too slow to account for the consumption of reactants and the formation of products, we also introduced the heterogeneous decomposition of HNO3 in our kinetic modeling. The heterogeneous decomposition rate of HNO3, HNO3 + (B2O3/SiO2) → OH + NO2 + (B2O3/SiO2), was determined by varying its rate to match the modeled result to the measured concentrations of NH3 and H2O; the rate could be represented by k2b = 7.91 × 107 exp(-12 600/T) s-1, which appears to be consistent with those reported by Johnston and co-workers (Johnston, H. S.; Foering, L.; Tao, Y.-S.; Messerly, G. H. J. Am. Chem. Soc. 1951, 73, 2319-2321) for HNO3 decomposition on glass reactors at higher temperatures. Notably, the concentration profiles of all species measured could be satisfactorily predicted by the existing [H,N,O]-mechanism with the heterogeneous initiation process.

  18. How salicylic acid takes transcriptional control over jasmonic acid signaling

    NARCIS (Netherlands)

    Caarls, Lotte|info:eu-repo/dai/nl/371746213; Pieterse, Corné M J|info:eu-repo/dai/nl/113115113; van Wees, Saskia C M|info:eu-repo/dai/nl/185445373

    2015-01-01

    Transcriptional regulation is a central process in plant immunity. The induction or repression of defense genes is orchestrated by signaling networks that are directed by plant hormones of which salicylic acid (SA) and jasmonic acid (JA) are the major players. Extensive cross-communication between

  19. C-11 Acid and the Stereochemistry of Abietic Acid

    Indian Academy of Sciences (India)

    IAS Admin

    While many features, like the phenanthrene-type of fusion of the three ... thought to contain the original ring A of abietic acid, retaining the. 'nuclear methyl .... Thinking that the anhydride he had obtained by the action of heat on the C-11 acid ...

  20. Composition of amino acids, fatty acids and dietary fibre monomers ...

    African Journals Online (AJOL)

    There is increasing demand for sources of energy and non-meat protein with balanced amino acid profiles worldwide. Nuts are rich in protein and essential amino acids, and have a high energy value due to their high fat content. Kernels from two wild fruits in Mozambique, Adansonia digitata and Sclerocarya birrea, were ...

  1. Application of citric acid in acid stimulation treatments

    Energy Technology Data Exchange (ETDEWEB)

    Alkhaldi, M.H.; Sarma, H.K. [Adelaide Univ., Adelaide (Australia); Nasr-el-Din, H.A. [Texas A and M Univ., College Station, TX (United States)

    2009-07-01

    A rotating disk apparatus was used to investigate mass transfer during the reaction of citric acid with calcite. The study evaluated the effects of initial acid concentrations, temperature, and disk rotational speed on the effective diffusion coefficient of citric acid. The diffusion coefficient was calculated at 25, 40, and 50 degrees C using various citric acid concentrations. The study indicated that the coefficient was a function of the interactions between calcium citrate precipitation and counter calcium ions. At high acid concentrations, the effects of calcium citrate precipitation and counter calcium ions were significant. The calculated citric acid diffusion coefficients were not comparable with measured effective diffusion coefficients using the rotating disk. At lower initial citric acid concentrations, the effects of both calcium citrate precipitation and counter calcium ions on citric acid diffusivity were minimal. It was concluded that temperature effects on the diffusion coefficient followed Arrhenius law. Activation energy was equal to 37.9 kJ/mol. 34 refs., 4 tabs., 13 figs.

  2. Bile acid analysis in human disorders of bile acid biosynthesis

    NARCIS (Netherlands)

    Vaz, Frédéric M.; Ferdinandusse, Sacha

    2017-01-01

    Bile acids facilitate the absorption of lipids in the gut, but are also needed to maintain cholesterol homeostasis, induce bile flow, excrete toxic substances and regulate energy metabolism by acting as signaling molecules. Bile acid biosynthesis is a complex process distributed across many cellular

  3. Peptide Nucleic Acids Having Amino Acid Side Chains

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than the corresponding DNA or RNA strands, and exhibit increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a group consisting...

  4. Biopropionic acid production via molybdenumcatalyzed deoxygenation of lactic acid

    NARCIS (Netherlands)

    Korstanje, T.J.; Kleijn, H.; Jastrzebski, J.T.B.H.; Klein Gebbink, R.J.M.

    2013-01-01

    As the search for non-fossil based building blocks for the chemical industry increases, new methods for the deoxygenation of biomass-derived substrates are required. Here we present the deoxygenation of lactic acid to propionic acid, using a catalyst based on the non-noble and abundant metal

  5. Cytotoxic effect of betulinic acid and betulinic acid acetate isolated ...

    African Journals Online (AJOL)

    GREGORY

    2010-09-20

    Sep 20, 2010 ... Betulinic acid acetate (BAAC) was most effective than other betulinic acid derivatives. It had most ... blastoma (Schmidt et al., 1997), malignant brain tumor .... 96 well plate and incubated in 37oC, 5% CO2 and 90% humidity.

  6. Classifying Your Food as Acid, Low-Acid, or Acidified

    OpenAIRE

    Bacon, Karleigh

    2012-01-01

    As a food entrepreneur, you should be aware of how ingredients in your product make the food look, feel, and taste; as well as how the ingredients create environments for microorganisms like bacteria, yeast, and molds to survive and grow. This guide will help you classifying your food as acid, low-acid, or acidified.

  7. Analysis of Rock-Geological Material From Places in Tanzania by ...

    African Journals Online (AJOL)

    Dispersive X-ray Fluorescence (WDXRF) Analysis has been used with objective of ... The samples identified and reported in this paper include: Iron ore, ... The samples were prepared as pellets after mixing with boric acid or fused as discs for

  8. Neutron shielding material and a process for producing the same

    International Nuclear Information System (INIS)

    Tadokoro, S.; Segawa, H.

    1982-01-01

    A neutron shielding material comprises a polymerization product of a monomer mixture of an alkyl methacrylate or styrene and a boric acid containing a polyol constituent. Such a material may be formed into transparent sheets with high mechanical strength

  9. Plutonium determination in solution with excess hydrofluoric acid

    International Nuclear Information System (INIS)

    Krtil, J.; Kuvik, V.; Spevackova, V.

    1975-01-01

    The determination is described of plutonium in solutions in the presence of fluoride ions resulting from the hydrolysis of PuF 6 . The method is based on reduction of Pu(VI) by excess of Fe(II) and on re-titration of Fe(II) with ceric salt. The effect of fluoride ions on plutonium determination was studied. It was found that a 3 mole excess of HF with respect to Pu decreased the results of Pu determination. The interference of fluoride ions was eliminated by a two-fold evaporation of the solution to be titrated with HNO 3 to dryness or by complex formation with boric arid. The amount of 20.50 mg Pu in the presence of a 10 mole excess of fluoride ions (17 mg HF) was determined with an error of +- 0.09 mg ). (author)

  10. Origin of nucleic acids

    International Nuclear Information System (INIS)

    Prieur, B.E.

    1995-01-01

    The appearance of nucleic acids is the first event after the birth of membranes which made it possible to assure the perenniality of information. The complexity of these molecules has led some scientists to propose that they were not prebiotic but rather derived a more simple and achiral primitive ancestor. This hypothesis suggests that ribose possesses properties that allowed the formation of certain polysaccharides which evolved to RNA. The first step of the hypothesis is the selection and concentration of ribofuranose. This sugar has chelating properties and its alpha-ribofuranose is favoured in the chelating position. The density of the sugar with a heavy cation is greater than water and thus the complex can escape the UV radiation at the surface of the ocean. The particularity of ribose is to be able to form a homochiral regular array of these basic chelating structures with pyrophosphite. These arrays evolve towards the formation of polysaccharides (poly ribose phosphate) which have a very organized structure. These polysaccharides in turn evolve to RNA by binding of adenine and deoxyguanine which are HCN derivatives that can react with the polysaccharides. The primitive RNA is methylated and oxidized to form prebiotic RNA with adenosine, cytidine, 7methyl-guanosine and ribothymidine as nucleic bases. The pathway of biosynthesis of DNA form RNA will be studied. I suggest that the appearance of DNA results form the interaction between prebiotic double stranded RNA and proteins. DNA could be a product of RNA degradation by proteins. The catabolism of RNA to DNA requires a source of free radicals, protons and hydrides. RNA cannot produce free radicals, which are provided by the phenol group of the amino acid tyrosien. Protons are provided by the medium and hydrides are provided by 7-methyl-guanosine which can fix hydrides coming from hydrogen gas and donate them for the transformation of a riboside to a deoxyriboside. This pathway suggests that DNA appeared at

  11. Preparation of fulvic acid and low-molecular organic acids by oxidation of weathered coal humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shinozuka, T.; Ito, A.; Sasaki, O.; Yazawa, Y.; Yamaguchi, T. [Chiba Institute of Technolgy, Chiba (Japan). Dept. of Industrial Chemistry

    2002-07-01

    Weathered coal contains much humic acid and a little fulvic acid. Therefore, the production of fulvic acid, the most valuable humic substance because of its water-solubility, was examined by ozone and hydrogen peroxide oxidation of humic acid extracted form Xinjiang (China) weathered coal. The resulting products of the oxidation were water soluble fulvic acid and organic acids, mainly formic acid and oxalic acid. The product yield of fulvic acid was 20 (C%) and that of organic acids were 39 (C%) for formic and acid 13 (C%) for oxalic acid. The formed fulvic acid showed a higher content of oxygen and carboxyl groups, than those of the extracted one from the original weathered coal.

  12. Ascorbic acid in bronchial asthma

    African Journals Online (AJOL)

    1983-04-23

    Apr 23, 1983 ... by comparing the pre-ascorbic acid results with those obtained 21/2 hours after the intravenous ... (ASO), C-reactive protein and antibodies to certain respiratory viruses. These investigations were ..... vitamin.6 However, other investigators were unable to detect any protective effects of ascorbic acid on the ...

  13. Chloroacetic acids in environmental processes

    Czech Academy of Sciences Publication Activity Database

    Matucha, Miroslav; Gryndler, Milan; Forczek, Sándor; Uhlířová, H.; Fuksová, Květoslava; Schröder, P.

    2003-01-01

    Roč. 1, - (2003), s. 127-130 ISSN 1610-3653 R&D Projects: GA ČR GA522/02/0874 Institutional research plan: CEZ:AV0Z5038910 Keywords : Dichloroacetic acid * Trichloroacetic acid * Microbial degradation Subject RIV: GK - Forestry

  14. Acid Rain: An Educational Opportunity?

    Science.gov (United States)

    Marion, James I.

    1984-01-01

    Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…

  15. Bile acids for viral hepatitis

    DEFF Research Database (Denmark)

    Chen, Weikeng; Liu, J; Gluud, C

    2003-01-01

    The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness.......The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness....

  16. Getting Back to Basics (& Acidics)

    Science.gov (United States)

    Rhodes, Sam

    2006-01-01

    This article describes a few novel acid-base experiments intended to introduce students to the basic concepts of acid-base chemistry and provide practical examples that apply directly to the study of biology and the human body. Important concepts such as the reaction between carbon dioxide and water, buffers and protein denaturation, are covered.…

  17. Reactive extraction and recovery of levulinic acid, formic acid and furfural from aqueous solutions containing sulphuric acid

    NARCIS (Netherlands)

    Brouwer, Thomas; Blahusiak, Marek; Babic, Katarina; Schuur, Boelo

    2017-01-01

    Levulinic acid (LA) can be produced from lignocellulosic materials via hydroxylation followed by an acid-catalyzed conversion of hexoses. Inorganic homogeneous catalysts are mostly used, in particular sulphuric acid, yielding a mixture of LA with sulphuric acid, formic acid (FA) and furfural.

  18. Studies on radiolysis of amino acids, (4)

    International Nuclear Information System (INIS)

    Oku, Tadatake

    1978-01-01

    In order to elucidate the effect of adding methionine on the loss of amino acid by γ-irradiation in amino acid mixture, because methionine is one of the most radio-sensitive in amino acids, the remaining amino acids in γ-irradiated aqueous solution of amino acid mixture were studied by determining the total amount of each remaining amino acid. The mixture of 18 amino acids which contains methionine and that of 17 amino acids without methionine were used. Amino acids and the irradiation products were determined with an automatic amino acid analyzer. The total amount of remaining amino acids in the irradiated solution of 18 amino acid mixture was more than that of 17 amino acid mixture. The order of the total amount of each remaining amino acid by low-dose irradiation was Gly>Ala>Asp>Glu>Val>Ser, Pro>Ile, Leu>Thr>Lys>Tyr>Arg>His>Phe>Try>Cys>Met. In case of the comparison of amino acids of same kinds, the total remaining amount of each amino acid in amino acid mixture was more than that of individually irradiated amino acid. The total remaining amounts of glycine, alanine and aspartic acid in irradiated 17 amino acid mixture resulted in slight increase. Ninhydrin positive products formed from 18 amino acid mixture irradiated with 2.640 x 10 3 rad were ammonia, methionine sulfoxide and DOPA of 1.34, 0.001 and 0.25 μmoles/ml of the irradiated solution, respectively. (Kobake, H.)

  19. Valproic Acid-induced Agranulocytosis

    Directory of Open Access Journals (Sweden)

    Hui-Chuan Hsu

    2009-06-01

    Full Text Available Valproic acid is considered to be the most well-tolerated antiepileptic drug. However, few cases of neutropenia or leukopenia caused by valproic acid have been reported. We present a patient who took valproic acid to treat a complication of brain surgery and in whom severe agranulocytosis occurred after 2.5 months. Valproic acid was stopped immediately, and granulocyte colony-stimulating factor was administered for 2 days. The patient's white blood cell count returned to normal within 2 weeks. The result of bone marrow aspiration was compatible with drug-induced agranulocytosis. This case illustrates that patients who take valproic acid may need regular checking of complete blood cell count.

  20. N-(3-Nitrophenylmaleamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-07-01

    Full Text Available In the title compound, C10H8N2O5, the molecule is slightly distorted from planarity. The molecular structure is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond (H...O distance = 1.57 Å within the maleamic acid unit and the second is a C—H...O hydrogen bond (H...O distance = 2.24 Å which connects the amide group with the benzene ring. The nitro group is twisted by 6.2 (2° out of the plane of the benzene ring. The crystal structure manifests a variety of hydrogen bonding. The packing is dominated by a strong intermolecular N—H...O interaction which links the molecules into chains running along the b axis. The chains within a plane are further assembled by three additional types of intermolecular C—H...O hydrogen bonds to form a sheet parallel to the (overline{1}01 plane.

  1. Bioactive phenolic acids from Scorzonera radiata Fisch.

    Directory of Open Access Journals (Sweden)

    N Tsevegsuren

    2014-09-01

    Full Text Available Chromatographic separation of the crude extract obtained from the aerial parts of the Mongolian medicinal plant Scorzonera radiata yielded five new dihydrostilbenes [4], two new flavonoids, one new quinic acid derivative, as well as twenty known compounds including eight quinic acid derivatives, four flavonoids, two coumarins, five simple benzoic acids, and one monoterpene glycoside. We present here results on isolation and structural identification some active phenolic compounds from the Scorzonera radiata - eight quinic acid derivatives (quinic acid, 4,5-dicaffeoylquinic acid, 4,5-dicaffeoyl-epi-quinic acid, 3,5-dicaffeoylquinic acid, 3,5-dicaffeoyl-epi-quinic acid, chlorogenic acid, 5-p-coumaroylquinic acid (trans, 5-p-coumaroylquinic acid (cis. Quinic acid derivatives exhibited antioxidative activity.DOI: http://dx.doi.org/10.5564/mjc.v12i0.177 Mongolian Journal of Chemistry Vol.12 2011: 78-84

  2. Biophysical properties of phenyl succinic acid derivatised hyaluronic acid

    DEFF Research Database (Denmark)

    Neves-Petersen, Maria Teresa; Klitgaard, Søren; Skovsen, Esben

    2010-01-01

    Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic materials. In the present study, hyaluronic...... acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA). The fluorescence of PheSA was efficiently quenched by the HA matrix. HA also acted as a singlet oxygen scavenger. Fluorescence lifetime(s) of PheSA in solution and when attached to the HA matrix has been monitored...

  3. Metalworking and machining fluids

    Science.gov (United States)

    Erdemir, Ali; Sykora, Frank; Dorbeck, Mark

    2010-10-12

    Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

  4. Composition and method for coke retardant during hydrocarbon processing

    International Nuclear Information System (INIS)

    Reid, D.K.

    1988-01-01

    A process is described for inhibiting the formation and deposition of filamentous coke on metallic surfaces in contact with a hydrocarbon having a temperature of 600 0 -1300 0 F which comprises adding to the hydrocarbon a sufficient amount for the purpose of a boron compound selected from the group of boron oxide compounds, boric acid and metal borides, with the proviso that when boric acid is used, it is substantially free of water

  5. Leaching of nuclear power reactor wastes forms

    International Nuclear Information System (INIS)

    Endo, L.S.; Villalobos, J.P.; Miyamoto, H.

    1986-01-01

    The leaching tests for power reactor wastes carried out at IPEN/CNEN-SP are described. These waste forms consist mainly of spent resins and boric acid concentrates solidified in ordinary Portland cement. All tests were conducted according to the ISO and IAEA recommendations. 3 years leaching results are reported, determining cesium and strontium diffusivity coefficients for boric acid waste form and ion-exchange resins. (Author) [pt

  6. Method for preparation of borax decahydrate

    International Nuclear Information System (INIS)

    Dujnedenko, V.I.; Chumaevskij, V.A.; Kovalev, A.S.; Gabova, E.L.; Suvorova, M.R.; Smirnova, V.G.; Smirnov, A.S.

    1990-01-01

    A highly productive method of borax decahydrate preparation, consisting in the mixing of boric acid, soda and mother solution at the temperature not exceeding 40 deg is described. The mixture is supplied to borax circulating solution at the temperature of 85-95 deg. After crystallization borax decahydrate is isolated from mother solution and solution is directed for mixing with boric acid and soda. The given method permits to increase the process productivity 3.75-4.50 fold

  7. Effect of boron compounds on the thermal and combustion properties of wood-plastic composites

    OpenAIRE

    Altuntaş, Ertuğrul; Karaoğul, Eyyup; Alma, Mehmet Hakkı

    2017-01-01

    In this study, the thermal properties and fire resistancesof the wood plastic composites produced with waste lignocellulosic materialswere investigated. For this purpose, lignocellulosic waste, high densitypolyethylene, (HDPE) sodium borate (borax) and boric acid was used to producethe wood-plastic composites. A twin-screw extruder was used during theproduction of the wood plastic composites. The produced composite granule waspressed at 175 °C hot press. The effects of boric acid and borax ad...

  8. Analytical application of aminohydroxamic acids

    International Nuclear Information System (INIS)

    Fadl Elmoula, Abd ELfatah Abdella

    2000-11-01

    Anthranilic hydroxamic acid was prepared by coupling of methylanthranilate (prepared by esterification of anthranilic acid with methyl alcohol using the fisher-speir method) with freshly prepared hydroxylamine. The lignad was characterized by the usual reaction of hydroxamic acid with acidic V(V) and Fe(III) solutions that gives blood-red colour in amyl alcohol and deep-violet colour in aqueous solution, respectively. The absorbance of Fe(III)-hydroxamic acids complexes increases with increase of pH. In this study, the effect of pH on the absorbance of Fe(III)-anthranilic hydroxamic acid was in accordance with this trend. The maximum absorbance was obtained at pH 5.0 at maximum wavelength of 482 nm. For Cu(II)-anthranilic hydroxamic acid complex, the use of acidic basic pH lead to precipitation of Cu(II)-ligand complex. But when using buffer pH (acetic acid/sodium acetate) a clear green colour of Cu(II)-ligand complex was obtained. The maximum wavelength of 390 nm. V(V)-anthranilic hydroxamic acid complex was extracted in acidic medium in amyl alcohol at pH 2.0 because in aqueous solution V(V)-anthranilic hydroxamic acid complex has not clear colour. It was observed the the maximum extraction in acidic medium decrease sharply with the increasing of pH value. The maximum wavelength for maximum absorbance was recorded at 472 nm. V(V) interfered with determination of Fe(III)) above concentration of 2 ppm, whereas Cu(II) interferes slightly with the determination of Fe(III) ions even at a high concentration of the Cu(II) ions. Both Cu(II) and Ni(II) do not interfere with the determination of V(V) ions even at high concentrations, Fe(III) ion produced slight interference, while Mo(VI) ions have a pronounced interference. Both V(V) and Fe(III) ions interfered markedly with the determination of Cu(II) ions, and made impractical under conditions. However, the calibration curves for the three metal ions produced a practical linear dynamic range.(Author)

  9. Placement of acid spoil materials

    Energy Technology Data Exchange (ETDEWEB)

    Pionke, H B; Rogowski, A S

    1982-06-01

    Potentially there are several chemical and hydrologic problems associated with placement of acid spoil materials. The rationale for a deep placement well below the soil surface, and preferably below a water table, is to prevent or minimize oxidation of pyrite to sulfuric acid and associated salts by reducing the supply of oxygen. If, however, substantial sulfuric acid or associated salts are already contained within the spoil because of present or previous mining, handling and reclamation operations (or if large supplies of indigenous salts exist, placement below a water table) may actually increase the rate of acid and salt leaching. Specific placement of acid- and salt-containing spoil should be aimed at preventing contact with percolating water or rising water tables. We recommend placement based on chemical and physical spoil properties that may affect water percolation O/sub 2/ diffusion rates in the profile. Both the deeper placement of acid spoil and coarser particle size can substantially reduce the amount of acid drainage. Placement above the water table with emphasis on percolate control may be better for high sulfate spoils, while placement below the non-fluctuating water table may be better for pyritic spoils.

  10. Aquatic chemistry of acid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Stumm, W; Sigg, L; Schnoor, J L

    1987-01-01

    The occurrence of acid precipitation in many regions of the Northern hemisphere is a consequnece of human interference in the cycles that unite land, water and atmosphere. The oxidation of carbon, sulfur and nitrogen, resulting mostly from fossil fuel burning, rivals oxidation processes induced by photosynthesis and respiration and disturbs redox conditions in the atmosphere. The paper discusses oxidation-reduction reactions, particularly those involving atmospheric pollutants that are important in the formation of acid precipitation. Topics covered are: a stoichiometric model of acid rain formation; sulfur dioxide and ammonia adsorption; acid neutralizing capacity. The paper concludes that explanations of simple chemical equilibria between gases and water aid our understanding of how acidifying gases become dissolved in cloud water, in droplets of falling rain, or in fog. Rigorous definitions of base- or acid-neutralizing capacities are prerequisites to measuring and interpreting residual acidity in dry and wet deposition and for assessing the disturbance caused by the transfer of acid to terrestrial and aquatic ecosystems. 20 references.

  11. catalyzed oxidation of some amino acids by acid bromate

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT: Kinetic investigations on Pd(II) catalyzed oxidation of dl-serine and dl- ... A suitable mechanism in agreement with observed kinetics has been ..... In acidic solution of potassium bromate quick .... Annual Review of Biochemistry.

  12. Cytotoxic effect of betulinic acid and betulinic acid acetate isolated ...

    African Journals Online (AJOL)

    GREGORY

    2010-09-20

    Sep 20, 2010 ... Betulinic acid exerts a selective anti-tumor activity on cultured human melanoma .... percentage of proliferation was calculated by the following formula: Proliferation ..... artificially imposing the cell cycle checkpoint. Among.

  13. Influence of fluorozirconic acid on sulfuric acid anodizing of aluminum

    OpenAIRE

    Elaish, R.; Curioni, M.; Gowers, K.; Kasuga, A.; Habazaki, H.; Hashimoto, T.; Skeldon, P.

    2017-01-01

    The effects of additions of fluorozirconic acid to sulfuric acid on the anodizing behavior of aluminum have been investigated under a constant voltage at temperatures of 0 and 20◦C. The fluoroacid increased the rate of film growth, with a dependence on the fluoroacid concentration, the electrolyte temperature and the anodizing time. Compositional analyses showed that fluorine species were present in the films. However, zirconium species were absent. The fluoroacid generally enhanced film diss...

  14. Docosahexaenoic acid affects arachidonic acid uptake in megakaryocytes

    International Nuclear Information System (INIS)

    Schick, P.K.; Webster, P.

    1987-01-01

    Dietary omega 3 fatty acids are thought to prevent atherosclerosis, possibly by modifying platelet (PT) function and arachidonic acid (20:4) metabolism. The study was designed to determine whether omega 3 fatty acids primarily affect 20:4 metabolism in megakaryocytes (MK), bone marrow precursors of PT, rather than in circulating PT. MK and PT were isolated from guinea pigs and incubated with [ 14 C]-20:4 (0.13uM). Docosahexaenoic acid (22:6) is a major omega 3 fatty acid in marine oils. The incubation of MK with 22:6 (0.1, 1.0 uM) resulted in the decrease of incorporation of [ 14 C]-20:4 into total MK phospholipids, 16% and 41% respectively. Alpha-linolenic acid (18:3), a major omega 3 fatty acid present in American diets, had no effect on 20:4 uptake in MK. 22:6 primarily affected the uptake of [ 14 C]-20:4 into phosphatidylethanolamine (PE) and phosphatidylserine (PS) in MK. In MK, 22:6 (0.1, 1.0 uM) caused a decrease of incorporation of [ 14 C]-20:4 into PE, 21% and 55% respectively; a decrease into PS, 16% and 48% respectively; but only a decrease of 4% and 18%, respectively, into phosphatidylcholine; and a decrease of 3% and 21% into phosphatidylinositol 22:6 (3.0 uM) had no effect on the uptake of AA into PT phospholipids. The study shows that 22:6 has a selective effect on AA uptake in MK and that the acylation or transacylation of PE and PS are primarily affected. 22:6 and other marine omega 3 fatty acids appear to primarily affect megakaryocytes which may result in the production of platelets with abnormal content and compartmentalization of AA

  15. Treatment of acid mine wastewaters

    International Nuclear Information System (INIS)

    Hayward, D.; Barnard, R.

    1993-01-01

    Acid mine drainage often results from the oxidation sulfide minerals to form sulfuric acid. As a consequence, high concentrations of metals in the both the suspended and dissolved state result from the low pH water. This paper discusses several of the more common treatment methods for acid mine drainage including the use of chemical precipitation agents, pH correction agents, filtration methods, and biodegradation methods. Advanced treatment technologies are also briefly described and include microfiltration, reverse osmosis, ion exchange, and electrodialysis

  16. Amino Acids from a Comet

    Science.gov (United States)

    Cook, Jamie Elisla

    2009-01-01

    NASA's Stardust spacecraft returned samples from comet 81P/Wild 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds (cometary- vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these amino acids to determine their origin, leading to the first detection of a coetary amino acid.

  17. PRODUCTION OF TRIFLUOROACETIC ACID COMPOUNDS

    Science.gov (United States)

    Haworth, W.N.; Stacey, M.

    1949-08-30

    A process is described for the preparation of trifluoroacetic acid. Acetone vapor diluted wlth nitrogen and fluorine also diluted with nltrogen are fed separately at a temperature of about 210 deg C into a reaction vessel containing a catalyst mass selected from-the group consisting of silver and gold. The temperature in the reaction vessel is maintained in the range of 200 deg to 250 deg C. The reaction product, trifluoroacetyl fluoride, is absorbed in aqueous alkali solution. Trifluoroacetic acid is recovered from the solution by acidification wlth an acid such as sulfuric followed by steam distillation.

  18. Arsanilic acid blindness in pigs

    Energy Technology Data Exchange (ETDEWEB)

    Menges, R.W.; Kintner, L.D.; Selby, L.A.; Stewart, R.W.; Marlenfeld, C.J.

    1970-06-01

    Blindness in pigs that were given an overdosage of arsanilic acid is reported. A 0.0375% level of arsanilic acid was fed to 640 pigs for 90 days beginning when the animals were 3 months old. Approximately one month after the start of feeding, partial or complete blindness was observed in 50 of the pigs. Clinical signs, pathologic findings and the chemical analysis of hair are discussed. The level of arsanilic acid used was that recommended for the control of swine dysentery, to be fed for only five or six days. The overdosage resulted from a misunderstanding between the farmer and the feed mill.

  19. Boron isotope separation by ion exchange chromatography using weakly basic anion exchange resin

    International Nuclear Information System (INIS)

    Itoh, S.; Aida, M.; Okamoto, M.; Nomura, M.; Fujii, Y.

    1985-01-01

    Influences of operating temperatures and concentrations of feed boric acid solutions were examined on the above titled process over the ranges of 25 - 70 0 C and 0.1 - 1.6 mol/dm 3 (M), respectively. The ideal displacement chromatography with a very sharp-cut boundary of the boric acid adsorption band was realized at higher temperatures and lower boric acid concentrations within the experimental conditions. The isotope separation coefficient epsilon was found to decrease with increases in either temperature or the boric acid concentration. The observed values of epsilon at 25 0 C were 0.013, 0.012 and 0.011 corresponding to feed boric acid concentrations of 0.1 M, 0.4 M and 0.8 M, respectively. The epsilon's at 70 0 C were 0.0097 (0.1 M), 0.0086 (0.4 M), 0.0083 (0.8 M) and 0.0073 (1.6 M). A temperature of 40 0 C and 0.4 M of boric acid concentration was considered the optimum operating condition for the production of enriched 10 B. (author)

  20. Molar extinction coefficients of some fatty acids

    DEFF Research Database (Denmark)

    Sandhu, G.K.; Singh, K.; Lark, B.S.

    2002-01-01

    ) and stearic acid (C18H36O2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good agreement......The attenuation of gamma rays in some fatty acids, viz. formic acid (CH2O2), acetic acid (C2H4O2), propionic acid (C3H6O2), butyric acid (C4H8O2), n-hexanoic acid (C6H12O2), n-caprylic acid (C8H16O2), lauric acid (C12H24O2), myristic acid (C14H28O2), palmitic acid (C16H32O2), oleic acid (C18H34O2...

  1. Studies on radiolysis of amino acids, 1

    International Nuclear Information System (INIS)

    Oku, Tadatake

    1977-01-01

    In order to elucidate the radiolysis of amino acid, peptide, protein and enzyme, the radiolytic mechanisms of neutral amino acids (glycine, L-alanine, L-valine, L-leucine, L-isoleucine, L-serine, and L-threonine) and acidic amino acids (L-aspartic acid, L-glutamic acid and DL-amino-n-adipic acid) were studied in the presence of air or in the atmosphere nitrogen. An aqueous solution of 1 mM. of each amino acid was sealed in a glass ampoule under air or nitrogen. Irradiation of amino acid solutions was carried out with γ-rays of 60 Co at doses of 4.4-2,640x10 3 rads. The amino acids and the radiolytic products formed were determined by ion-exchange chromatography. From the results of determining amino acids and the radiolytic products formed and their G-values, the radiolytic mechanisms of the amino acids were discussed. (auth.)

  2. Ectopic expression of Crambe abyssinica lysophosphatidic acid ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... lysophosphatidic acid acyltransferase in transgenic rapeseed increases its oil .... pathway [fatty acid desaturase-2 (BnFAD2, AY577313), fatty acid desaturase-3 ..... Acyltransferases from basic science to modified seed oils.

  3. Treatment of Fatty Acid Oxidation Disorders

    Science.gov (United States)

    ... Treatment of fatty acid oxidation disorders Treatment of fatty acid oxidation disorders E-mail to a friend Please ... this page It's been added to your dashboard . Fatty acid oxidation disorders are rare health conditions that affect ...

  4. Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats

    DEFF Research Database (Denmark)

    Zhou, A; Farver, O; Thorn, N A

    1991-01-01

    . Dehydroascorbic acid was converted to ascorbic acid by an unknown mechanism after uptake. The uptake of both ascorbic acid and dehydroascorbic acid was inhibited by tri-iodothyronine, and uptake of ascorbic acid, but not of dehydroascorbic acid, was inhibited by glucocorticoids. Isolated secretory granules...

  5. Increased Bile Acid Synthesis and Impaired Bile Acid Transport in Human Obesity

    OpenAIRE

    Haeusler, Rebecca A.; Camastra, Stefania; Nannipieri, Monica; Astiarraga, Brenno; Castro-Perez, Jose; Xie, Dan; Wang, Liangsu; Chakravarthy, Manu; Ferrannini, Ele

    2015-01-01

    We measured plasma bile acids, markers of bile acid synthesis, and expression of bile acid transporters in obese and nonobese subjects. We found that obesity was associated with increased bile acid synthesis and 12-hydroxylation, blunted response of plasma bile acids to insulin infusion or a mixed meal, and decreased expression of liver bile acid transporters.

  6. Simultaneous analysis of small organic acids and humic acids using high performance size exclusion chromatography

    NARCIS (Netherlands)

    Qin, X.P.; Liu, F.; Wang, G.C.; Weng, L.P.

    2012-01-01

    An accurate and fast method for simultaneous determination of small organic acids and much larger humic acids was developed using high performance size exclusion chromatography. Two small organic acids, i.e. salicylic acid and 2,3-dihydroxybenzoic acid, and one purified humic acid material were used

  7. 21 CFR 172.862 - Oleic acid derived from tall oil fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Oleic acid derived from tall oil fatty acids. 172... FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.862 Oleic acid derived from tall oil fatty acids. The food additive oleic acid derived from tall oil fatty acids may be safely used in food and as...

  8. Thermometric titration of acids in pyridine.

    Science.gov (United States)

    Vidal, R; Mukherjee, L M

    1974-04-01

    Thermometric titration of HClO(4), HI, HNO(3), HBr, picric acid o-nitrobenzoic acid, 2,4- and 2,5-dinitrophenol, acetic acid and benzoic acid have been attempted in pyridine as solvent, using 1,3-diphenylguanidine as the base. Except in the case of 2,5-dinitrophenol, acetic acid and benzoic acid, the results are, in general, reasonably satisfactory. The approximate molar heats of neutralization have been calculated.

  9. 21 CFR 184.1091 - Succinic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Succinic acid. 184.1091 Section 184.1091 Food and... Substances Affirmed as GRAS § 184.1091 Succinic acid. (a) Succinic acid (C4H6O4, CAS Reg. No. 110-15-6), also referred to as amber acid and ethylenesuccinic acid, is the chemical 1,4-butanedioic acid. It is...

  10. Mannuronic Acids : Reactivity and Selectivity

    NARCIS (Netherlands)

    Codee, Jeroen D. C.; Walvoort, Marthe T. C.; de Jong, Ana-Rae; Lodder, Gerrit; Overkleeft, Herman S.; van der Marel, Gijsbert A.

    2011-01-01

    This review describes our recent studies toward the reactivity and selectivity of mannopyranosyl uronic acid donors, which have been found to be very powerful donors for the construction of beta-mannosidic linkages.

  11. Vanadocene reactions with hydroxy acids

    International Nuclear Information System (INIS)

    Latyaeva, V.N.; Lineva, A.N.; Zimina, S.V.; Ehllert, O.G.; Arsen'eva, T.I.

    1984-01-01

    To prepare a series of vanadium cyclopentadienylcarboxylates soluble in water, the vanadocene reactions with lactic, γ-oxybutyric-, salicylic,- gallic-, orotic-, and acetylsalicylic acids have been studied. To determine the influence of cyclopentadienyl groups, bound with a vanadium atom, on the physiological activity of the complexes formed, vanadium halides are made to react with lactic acid. Only the vanadocene reaction with orotic acid was conducted in an aqueous medium, other interactions were realized in the diethyl ether, toluene, T, H, P medium. The interaction of vanadocene and vanadium halides with lactic-, salicylic-, acetylsalicylic- and gallic acids was found to lead to the formation of water-soluble vanadium complexes of Cp 2 , VOCOR or CpV (OCOR) 2 type. The data on the produced compounds yield, their IR spectra, decomposition temperatures, solubility, effective magnetic moments are presented

  12. Uranium extraction from phosphoric acid

    International Nuclear Information System (INIS)

    Lounis, A.

    1983-05-01

    A study has been carried out for the extraction of uranium from phosphoric acid produced in Algeria. First of all, the Algerian phosphoric acid produced in Algeria by SONATRACH has been characterised. This study helped us to synthesize a phosphoric acid that enabled us to pass from laboratory tests to pilot scale tests. We have then examined extraction and stripping parameters: diluent, DZEPHA/TOPO ratio and oxidising agent. The laboratory experiments enabled us to set the optimum condition for the choice of diluent, extractant concentration, ratio of the synergic mixture, oxidant concentration, redox potential. The equilibrium isotherms lead to the determination of the number of theoretical stages for the uranium extraction and stripping of uranium, then the extraction from phosphoric acid has been verified on a pilot scale (using a mixer-settler)

  13. Uronic acids in oligosaccharide synthesis

    NARCIS (Netherlands)

    Bos, Leendert Johannes van den

    2007-01-01

    This Thesis reports on research aimed at the assembly of acidic and zwitterionic polysaccharides of bacterial origin, using suitably protected 1-thioglycoside residues. Thioglycosides are attractive monosaccharide building blocks because of their high stability towards the diverse reaction

  14. Bile acid sequestrants for cholesterol

    Science.gov (United States)

    ... ency/patientinstructions/000787.htm Bile acid sequestrants for cholesterol To use the sharing features on this page, ... are medicines that help lower your LDL (bad) cholesterol . Too much cholesterol in your blood can stick ...

  15. N-substituted iminodiacetic acids

    International Nuclear Information System (INIS)

    Nunn, A.; Loberg, M.

    1982-01-01

    The chemical preparation of several new N-substituted iminodiacetic acid derivatives are described. These compounds when complexed with sup(99m)Tc provide useful radiopharmaceuticals for the external imaging of the hepatobiliary system. (U.K.)

  16. Compact oleic acid in HAMLET.

    Science.gov (United States)

    Fast, Jonas; Mossberg, Ann-Kristin; Nilsson, Hanna; Svanborg, Catharina; Akke, Mikael; Linse, Sara

    2005-11-07

    HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a complex between alpha-lactalbumin and oleic acid that induces apoptosis in tumor cells, but not in healthy cells. Heteronuclear nuclear magnetic resonance (NMR) spectroscopy was used to determine the structure of 13C-oleic acid in HAMLET, and to study the 15N-labeled protein. Nuclear Overhauser enhancement spectroscopy shows that the two ends of the fatty acid are in close proximity and close to the double bond, indicating that the oleic acid is bound to HAMLET in a compact conformation. The data further show that HAMLET is a partly unfolded/molten globule-like complex under physiological conditions.

  17. Nucleic Acid-Based Nanoconstructs

    Science.gov (United States)

    Focuses on the design, synthesis, characterization, and development of spherical nucleic acid constructs as effective nanotherapeutic, single-entity agents for the treatment of glioblastoma multiforme and prostate cancers.

  18. PHYSIOLOGY OF ACID BASE BALANCE

    Directory of Open Access Journals (Sweden)

    Awati

    2014-12-01

    Full Text Available Acid-base, electrolyte, and metabolic disturbances are common in the intensive care unit. Almost all critically ill patients often suffer from compound acid-base and electrolyte disorders. Successful evaluation and management of such patients requires recognition of common patterns (e.g., metabolic acidosis and the ability to dissect one disorder from another. The intensivists needs to identify and correct these condition with the easiest available tools as they are the associated with multiorgan failure. Understanding the elements of normal physiology in these areas is very important so as to diagnose the pathological condition and take adequate measures as early as possible. Arterial blood gas analysis is one such tool for early detection of acid base disorder. Physiology of acid base is complex and here is the attempt to simplify it in our day to day application for the benefit of critically ill patients.

  19. Structural features of lignohumic acids

    Czech Academy of Sciences Publication Activity Database

    Novák, František; Šestauberová, Martina; Hrabal, R.

    2015-01-01

    Roč. 1093, August (2015), s. 179-185 ISSN 0022-2860 Institutional support: RVO:60077344 Keywords : C-13 NMR * FTIR * humic acids * lignohumate * lignosulfonate * structure Subject RIV: DF - Soil Science Impact factor: 1.780, year: 2015

  20. Biomaterials made of bile acids

    Institute of Scientific and Technical Information of China (English)

    ZHANG JiaWei; ZHU XiaoXia

    2009-01-01

    The use of natural compounds in the preparation of new materials can improve the biocompatibility of the materials and avoid any potential toxicity of the degradation products when used for biomedical applications.Bile acids are amphiphilic molecules biosynthesized in the liver.They are used to prepare various polymers and oligomers.These polymers made of bile acids are promising materials in both biomedical and pharmaceutical fields.

  1. Biomaterials made of bile acids

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The use of natural compounds in the preparation of new materials can improve the biocompatibility of the materials and avoid any potential toxicity of the degradation products when used for biomedical applications. Bile acids are amphiphilic molecules biosynthesized in the liver. They are used to prepare various polymers and oligomers. These polymers made of bile acids are promising materials in both biomedical and pharmaceutical fields.

  2. Alternative to Nitric Acid Passivation

    Science.gov (United States)

    Kessel, Kurt R.

    2016-01-01

    Corrosion is an extensive problem that affects the National Aeronautics and Space Administration (NASA) and European Space Agency (ESA). The deleterious effects of corrosion result in steep costs, asset downtime affecting mission readiness, and safety risks to personnel. It is vital to reduce corrosion costs and risks in a sustainable manner. The primary objective of this effort is to qualify citric acid as an environmentally-preferable alternative to nitric acid for passivation of stainless steel alloys.

  3. Performance of Different Acids on Sandstone Formations

    Directory of Open Access Journals (Sweden)

    M. A. Zaman

    2013-12-01

    Full Text Available Stimulation of sandstone formations is a challenging task, which involves several chemicals and physical interactions of the acid with the formation. Some of these reactions may result in formation damage. Mud acid has been successfully used to stimulate sandstone reservoirs for a number of years. It is a mixture of hydrofluoric (HF and hydrochloric (HCl acids designed to dissolve clays and siliceous fines accumulated in the near-wellbore region. Matrix acidizing may also be used to increase formation permeability in undamaged wells. The change may be up to 50% to 100% with the mud acid. For any acidizing process, the selection of acid (Formulation and Concentration and the design (Pre-flush, Main Acid, After-flush is very important. Different researchers are using different combinations of acids with different concentrations to get the best results for acidization. Mainly the common practice is combination of Hydrochloric Acid – Hydrofluoric with Concentration (3% HF – 12% HCl. This paper presents the results of a laboratory investigation of Orthophosphoric acid instead of hydrochloric acid in one combination and the second combination is Fluoboric and formic acid and the third one is formic and hydrofluoric acid. The results are compared with the mud acid and the results calculated are porosity, permeability, and FESEM Analysis and Strength tests. All of these new combinations shows that these have the potential to be used as acidizing acids on sandstone formations.

  4. Ursodeoxycholic acid for nonalcoholic steatohepatitis.

    Science.gov (United States)

    Wu, Sheng-di; Li, Lei; Wang, Ji-yao

    2012-11-01

    The aim of this study was to evaluate the effects of ursodeoxycholic acid on patients with nonalcoholic steatohepatitis using meta-analysis. PubMed, EMBASE, Web of Science, Cochrane Library, Chinese Biomedical Databases, and article references were searched. We included randomized controlled trials using liver biopsy as a reference standard. We identified three eligible studies. Among histological responses, only lobular inflammation improved in the high-dose ursodeoxycholic acid subgroup compared with the control group [mean deviation (MD): -0.23 (-0.40, -0.06), P=0.008]. However, fibrosis may tend to increase [MD: 0.08 (-0.04, 0.20), P=0.17]. Among biochemical responses, γ-glutamyl transpeptidase reduction was significantly greater in the ursodeoxycholic acid group than in the placebo group, and the reduction tendency was only shown in the high-dose subgroup [MD: -35.58 (-52.60, -18.56), Pursodeoxycholic acid subgroup compared with the control group [MD: 0.43 (0.14, 0.72), P=0.004]. Ursodeoxycholic acid-treated patients did not differ significantly from control patients with regard to alanine transaminase, aspartate aminotransferase, and alkaline phosphatase activities. Adverse events were nonspecific and considered of no major clinical relevance. Ursodeoxycholic acid in monotherapy has no substantial positive effect on nonalcoholic steatohepatitis.

  5. Excitatory amino acid receptor antagonists

    DEFF Research Database (Denmark)

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B

    1997-01-01

    We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation......)-phenylethylamine salt of N-BOC-(R)-ATAA. Like ATAA, neither (R)- nor (S)-ATAA significantly affected (IC50 > 100 microM) the receptor binding of tritiated AMPA, kainic acid, or (RS)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid, the latter being a competitive NMDA antagonist. Electrophysiological experiments......, using the rat cortical wedge preparation, showed the NMDA antagonist effect as well as the AMPA antagonist effect of ATAA to reside exclusively in the (R)-enantiomer (Ki = 75 +/- 5 microM and 57 +/- 1 microM, respectively). Neither (R)- nor (S)-ATAA significantly reduced kainic acid-induced excitation...

  6. Effects of dietary conjugated linoleic acid and linoleic:linolenic acid ratio on polyunsaturated fatty acid status in laying hens.

    Science.gov (United States)

    Du, M; Ahn, D U; Sell, J L

    2000-12-01

    A study was conducted to determine the effects of dietary conjugated linoleic acid (CLA) and the ratio of linoleic:linolenic acid on long-chain polyunsaturated fatty acid status. Thirty-two 31-wk-old White Leghorn hens were randomly assigned to four diets containing 8.2% soy oil, 4.1% soy oil + 2.5% CLA (4.1% CLA source), 4.1% flax oil + 2.5% CLA, or 4.1% soy oil + 4.1% flax oil. Hens were fed the diets for 3 wk before eggs and tissues were collected for the study. Lipids were extracted from egg yolk and tissues, classes of egg yolk lipids were separated, and fatty acid concentrations of total lipids, triglyceride, phosphatidylethanolamine, and phosphatidylcholine were analyzed by gas chromatography. The concentrations of monounsaturated fatty acids and non-CLA polyunsaturated fatty acids were reduced after CLA feeding. The amount of arachidonic acid was decreased after CLA feeding in linoleic acid- and linolenic acid-rich diets, but amounts of eicosapentaenoic acid and docosahexaenoic acid were increased in the linolenic-rich diet, indicating that the synthesis or deposition of long-chain n-3 fatty acids was accelerated after CLA feeding. The increased docosahexaenoic acid and eicosapentaenoic acid contents in lipid may be compensation for the decreased arachidonic acid content. Dietary supplementation of linoleic acid increased n-6 fatty acid levels in lipids, whereas linolenic acid increased n-3 fatty acid levels. Results also suggest that CLA might not be elongated to synthesize long-chain fatty acids in significant amounts. The effect of CLA in reducing the level of n-6 fatty acids and promoting the level of n-3 fatty acids could be related to the biological effects of CLA.

  7. Specific bile acid radioimmunoassays for separate determinations of unconjugated cholic acid, conjugated cholic acid and conjugated deoxycholic acid in serum and their clinical application

    International Nuclear Information System (INIS)

    Matern, S.; Gerok, W.

    1977-01-01

    Specific radioimmunoassays for separate determinations of serum unconjugated cholic, conjugated cholic and conjugated deoxycholic acids have been developed. Prior to the radioimmunoassay, extraction of serum bile acids was performed with Amberlite XAD-2. Unconjugated cholic acid was separated from glyco- and taurocholic acids by thin-layer chromatography. At 50% displacement of bound labeled glyco[ 3 H]cholic acid using antiserum obtained after immunization with cholic acid-bovine serum albumin-conjugate the cross-reactivity of taurocholic acid was 100%, cholic acid 80%, glycochenodeoxycholic acid 10%, chenodeoxycholic acid 7%, conjugated deoxycholic acid 3%, and conjugated lithocholic acid 3 H]cholic acid was linear on a logit-log plot from 5 to 80 pmol of unlabeled glycocholic acid. Fasting serum conjugated cholic acid in healthy subjects was 0.68 +- 0.34 μmol/l. Unconjugated cholic acid was determined by a solid phase radioimmunoassay using the cholic acid antibody chemically bound to Sepharose. The displacement curve of [ 3 H]cholic acid in the solid phase radioimmunoassay was linear on a logit-log plot from 5 to 200 pmol of unlabeled cholic acid. The coefficient of variation between samples was 5%. Fasting serum conjugated deoxycholic acid concentrations in 10 healthy subjects ranged from 0.18 to 0.92 μmol/l determined by a radioimmunoassay using antiserum obtained after immunization with deoxycholic acid-bovine serum albumin-conjugate. The clinical application of these bile acid radioimmunoassays is shown by an 'oral cholate tolerance test' as a sensitive indicator of liver function and by an 'oral cholyglycine tolerance test' as a useful test for bile acid absorption. (orig.) [de

  8. Bile acids: regulation of apoptosis by ursodeoxycholic acid.

    Science.gov (United States)

    Amaral, Joana D; Viana, Ricardo J S; Ramalho, Rita M; Steer, Clifford J; Rodrigues, Cecília M P

    2009-09-01

    Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been related to membrane damage, but also to nondetergent effects, such as oxidative stress and apoptosis. Strikingly, hydrophilic ursodeoxycholic acid (UDCA), and its taurine-conjugated form (TUDCA), show profound cytoprotective properties. Indeed, these molecules have been described as potent inhibitors of classic pathways of apoptosis, although their precise mode of action remains to be clarified. UDCA, originally used for cholesterol gallstone dissolution, is currently considered the first choice therapy for several forms of cholestatic syndromes. However, the beneficial effects of both UDCA and TUDCA have been tested in other experimental pathological conditions with deregulated levels of apoptosis, including neurological disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Here, we review the role of bile acids in modulating the apoptosis process, emphasizing the anti-apoptotic effects of UDCA and TUDCA, as well as their potential use as novel and alternate therapeutic agents for the treatment of apoptosis-related diseases.

  9. [Regulating acid stress resistance of lactic acid bacteria--a review].

    Science.gov (United States)

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2014-07-04

    As cell factories, lactic acid bacteria are widely used in food, agriculture, pharmaceutical and other industries. Acid stress is one the important survival challenges encountered by lactic acid bacteria both in fermentation process and in the gastrointestinal tract. Recently, the development of systems biology and metabolic engineering brings unprecedented opportunity for further elucidating the acid tolerance mechanisms and improving the acid stress resistance of lactic acid bacteria. This review addresses physiological mechanisms of lactic acid bacteria during acid stress. Moreover, strategies to improve the acid stress resistance of lactic acid were proposed.

  10. Bile Acid Metabolism in Liver Pathobiology

    Science.gov (United States)

    Chiang, John Y. L.; Ferrell, Jessica M.

    2018-01-01

    Bile acids facilitate intestinal nutrient absorption and biliary cholesterol secretion to maintain bile acid homeostasis, which is essential for protecting liver and other tissues and cells from cholesterol and bile acid toxicity. Bile acid metabolism is tightly regulated by bile acid synthesis in the liver and bile acid biotransformation in the intestine. Bile acids are endogenous ligands that activate a complex network of nuclear receptor farnesoid X receptor and membrane G protein-coupled bile acid receptor-1 to regulate hepatic lipid and glucose metabolic homeostasis and energy metabolism. The gut-to-liver axis plays a critical role in the regulation of enterohepatic circulation of bile acids, bile acid pool size, and bile acid composition. Bile acids control gut bacteria overgrowth, and gut bacteria metabolize bile acids to regulate host metabolism. Alteration of bile acid metabolism by high-fat diets, sleep disruption, alcohol, and drugs reshapes gut microbiome and causes dysbiosis, obesity, and metabolic disorders. Gender differences in bile acid metabolism, FXR signaling, and gut microbiota have been linked to higher prevalence of fatty liver disease and hepatocellular carcinoma in males. Alteration of bile acid homeostasis contributes to cholestatic liver diseases, inflammatory diseases in the digestive system, obesity, and diabetes. Bile acid-activated receptors are potential therapeutic targets for developing drugs to treat metabolic disorders. PMID:29325602

  11. Determination of dissociation constants or propionic acid and lactic acid (2-hydroxypropionic acid) by potentiometry and conductometry

    International Nuclear Information System (INIS)

    Saeeduddin; Khanzada, A.W.K.

    2004-01-01

    Dissociation constants of propionic acid and 2-hydroxypropionic acid (lactic acid) have been studied at different temperatures between 25 to 50 deg. C interval. Propionic acid is analyzed by conductometry while 2-hydroxypropionic acid is analyzed by potentiometry. Both investigated compounds are symmetrical carboxylic acids having same length of carbon chain but are markedly different in ionic behavior. We were interested to see how the hydroxyl group (-OH) induction in propionic acid affects on pKa values of 2-hydroxypropionic acid. We observed that as temperature increases pKa values increase. The increase is observed for both the investigated compounds. PKa values of 2-hydroxypropionic acid are lower as compared to propionic acid because of electron withdrawing (-OH). (author)

  12. 17,21-Secohopanoic acids, 25-norhopanoic acids, and 28-norhopanoic acids in source rocks and crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Xueming Pan; Philp, R.P. [University of Oklahoma, Norman, OK (United States). School of Geology and Geophysics

    2006-09-15

    The presence of three families of hopanoic acids, 17,21-secohopanoic acids, 25-norhopanoic acids, and 28-norhopanoic acids, is discussed. Oils from West Siberia and tar balls from the Seychelles Islands were found to contain relatively high proportions of 17,21-secohopanoic acids. These acids have not been previously reported in any oils or source rocks. A heavily biodegraded West Siberian oil, was found to contain an homologous series of 25-norhopanoic acids co-occurring with the 25-norhopanes as previously reported in only a small number of oils from Campos Basin, Brazil. 28-Norhopanoic acids have been reported in various sediments and extracts of the Monterey Shale, but in this study their occurrence has been extended to oils, degraded oils, and tar balls sourced from the Monterey Shale. The primary purpose herein is to report the occurrence of these acids and possible relationships between the acids and corresponding hydrocarbons. (Author)

  13. Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron

    International Nuclear Information System (INIS)

    Jaen, J. A.; Gonzalez, L.; Vargas, A.; Olave, G.

    2003-01-01

    The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Moessbauer spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction was followed up to 3 months. Results indicated two different behaviors. At polyphenol concentrations higher than 1% iron converts to sparingly soluble and amorphous ferric (and ferrous) polyphenolate complexes. At lower concentrations (0.1%), the hydrolysis reactions are dominant, resulting in the formation of oxyhydroxides, which can be further reduced to compounds like magnetite by the polyphenols.

  14. Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron

    Energy Technology Data Exchange (ETDEWEB)

    Jaen, J. A., E-mail: jjaen@ancon.up.ac.p [Universidad de Panama, Departamento de Quimica Fisica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama); Gonzalez, L.; Vargas, A.; Olave, G. [Universidad de Panama, Escuela de Quimica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama)

    2003-06-15

    The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Moessbauer spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction was followed up to 3 months. Results indicated two different behaviors. At polyphenol concentrations higher than 1% iron converts to sparingly soluble and amorphous ferric (and ferrous) polyphenolate complexes. At lower concentrations (0.1%), the hydrolysis reactions are dominant, resulting in the formation of oxyhydroxides, which can be further reduced to compounds like magnetite by the polyphenols.

  15. The bile acids, deoxycholic acid and ursodeoxycholic acid, regulate colonic epithelial wound healing.

    Science.gov (United States)

    Mroz, Magdalena S; Lajczak, Natalia K; Goggins, Bridie J; Keely, Simon; Keely, Stephen J

    2018-03-01

    The intestinal epithelium constitutes an innate barrier which, upon injury, undergoes self-repair processes known as restitution. Although bile acids are known as important regulators of epithelial function in health and disease, their effects on wound healing processes are not yet clear. Here we set out to investigate the effects of the colonic bile acids, deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA), on epithelial restitution. Wound healing in T 84 cell monolayers grown on transparent, permeable supports was assessed over 48 h with or without bile acids. Cell migration was measured in Boyden chambers. mRNA and protein expression were measured by RT-PCR and Western blotting. DCA (50-150 µM) significantly inhibited wound closure in cultured epithelial monolayers and attenuated cell migration in Boyden chamber assays. DCA also induced nuclear accumulation of the farnesoid X receptor (FXR), whereas an FXR agonist, GW4064 (10 µM), inhibited wound closure. Both DCA and GW4064 attenuated the expression of CFTR Cl - channels, whereas inhibition of CFTR activity with either CFTR- inh -172 (10 µM) or GlyH-101 (25 µM) also prevented wound healing. Promoter/reporter assays revealed that FXR-induced downregulation of CFTR is mediated at the transcriptional level. In contrast, UDCA (50-150 µM) enhanced wound healing in vitro and prevented the effects of DCA. Finally, DCA inhibited and UDCA promoted mucosal healing in an in vivo mouse model. In conclusion, these studies suggest bile acids are important regulators of epithelial wound healing and are therefore good targets for development of new drugs to modulate intestinal barrier function in disease treatment. NEW & NOTEWORTHY The secondary bile acid, deoxycholic acid, inhibits colonic epithelial wound healing, an effect which appears to be mediated by activation of the nuclear bile acid receptor, FXR, with subsequent downregulation of CFTR expression and activity. In contrast, ursodeoxycholic acid promotes

  16. 15N NMR spectroscopic investigation of nitrous and nitric acids in sulfuric acid solutions of varying acidities

    International Nuclear Information System (INIS)

    Prakash, G.K.S.; Heiliger, L.; Olah, G.A.

    1990-01-01

    Both nitrous and nitric acids were studied in sulfuric acid solutions of varying acid strengths by 15 N NMR spectroscopy. The study gives new insights into the nature of intermediates present at different acid strengths. Furthermore, we have also discovered a novel redox reaction between NO 2 + and NO + ions involving the intermediacy of their respective acids. A mechanism is proposed to explain the observed results. 13 refs., 2 figs., 1 tab

  17. Distillation Separation of Hydrofluoric Acid and Nitric Acid from Acid Waste Using the Salt Effect on Vapor-Liquid Equilibrium

    Science.gov (United States)

    Yamamoto, Hideki; Sumoge, Iwao

    2011-03-01

    This study presents the distillation separation of hydrofluoric acid with use of the salt effect on the vapor-liquid equilibrium for acid aqueous solutions and acid mixtures. The vapor-liquid equilibrium of hydrofluoric acid + salt systems (fluorite, potassium nitrate, cesium nitrate) was measured using an apparatus made of perfluoro alkylvinylether. Cesium nitrate showed a salting-out effect on the vapor-liquid equilibrium of the hydrofluoric acid-water system. Fluorite and potassium nitrate showed a salting-in effect on the hydrofluoric acid-water system. Separation of hydrofluoric acid from an acid mixture containing nitric acid and hydrofluoric acid was tested by the simple distillation treatment using the salt effect of cesium nitrate (45 mass%). An acid mixture of nitric acid (5.0 mol · dm-3) and hydrofluoric acid (5.0 mol · dm-3) was prepared as a sample solution for distillation tests. The concentration of nitric acid in the first distillate decreased from 5.0 mol · dm-3 to 1.13 mol · dm-3, and the concentration of hydrofluoric acid increased to 5.41 mol · dm-3. This first distillate was further distilled without the addition of salt. The concentrations of hydrofluoric acid and nitric acid in the second distillate were 7.21 mol · dm-3 and 0.46 mol · dm-3, respectively. It was thus found that the salt effect on vapor-liquid equilibrium of acid mixtures was effective for the recycling of acids from acid mixture wastes.

  18. Branched-Chain Amino Acids

    Directory of Open Access Journals (Sweden)

    Matteo Ghiringhelli

    2015-07-01

    Full Text Available Our study is focused on evaluation and use of the most effective and correct nutrients. In particular, our attention is directed to the role of certain amino acids in cachectic patients. During parenteral nutrition in humans, physician already associates in the PN-bags different formulations including amino acids, lipids and glucose solutions or essential amino acids solution alone or exclusively branched-chain amino acids (BCAA. Studies investigated the effects of dietary BCAA ingestion on different diseases and conditions such as obesity and metabolic disorders, liver disease, muscle atrophy, cancer, impaired immunity or injuries (surgery, trauma, burns, and sepsis. BCAAs have been shown to affect gene expression, protein metabolism, apoptosis and regeneration of hepatocytes, and insulin resistance. They have also been shown to inhibit the proliferation of liver cancer cells in vitro, and are essential for lymphocyte proliferation and dendritic cell maturation. Oral or parenteral administration of these three amino acids will allow us to evaluate the real efficacy of these compounds during a therapy to treat malnutrition in subjects unable to feed themselves.

  19. 21 CFR 172.860 - Fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Fatty acids. 172.860 Section 172.860 Food and Drugs... Multipurpose Additives § 172.860 Fatty acids. The food additive fatty acids may be safely used in food and in... and their associated fatty acids manufactured from fats and oils derived from edible sources: Capric...

  20. SHORT COMMUNICATION DETERMINATION OF AMINO ACIDS ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    The purpose of this study was to assess the levels of free and total amino acid ... Gas chromatographic method with flame ionization detector (GC-FID) was ... Total amino acid analysis was done on acid hydrolysates of RJ samples by the ion-exchange ... The data of amino acids and protein content for all analyzed fresh and.

  1. 21 CFR 582.5013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ascorbic acid. 582.5013 Section 582.5013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5013 Ascorbic acid. (a) Product. Ascorbic acid. 1 Amino acids listed in this subpart may be...

  2. Effect of propionic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

    Science.gov (United States)

    Xu, Jian; Bao, Jia-Wei; Su, Xian-Feng; Zhang, Hong-Jian; Zeng, Xin; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2016-03-01

    In this study, an integrated citric acid-methane fermentation process was established to solve the problem of wastewater treatment in citric acid production. Citric acid wastewater was treated through anaerobic digestion and then the anaerobic digestion effluent (ADE) was further treated and recycled for the next batch citric acid fermentation. This process could eliminate wastewater discharge and reduce water resource consumption. Propionic acid was found in the ADE and its concentration continually increased in recycling. Effect of propionic acid on citric acid fermentation was investigated, and results indicated that influence of propionic acid on citric acid fermentation was contributed to the undissociated form. Citric acid fermentation was inhibited when the concentration of propionic acid was above 2, 4, and 6 mM in initial pH 4.0, 4.5 and, 5.0, respectively. However, low concentration of propionic acid could promote isomaltase activity which converted more isomaltose to available sugar, thereby increasing citric acid production. High concentration of propionic acid could influence the vitality of cell and prolong the lag phase, causing large amount of glucose still remaining in medium at the end of fermentation and decreasing citric acid production.

  3. Influence of acidified acidity to uranium bioleaching

    International Nuclear Information System (INIS)

    Li Jiang; Liu Yajie; Zheng Zhihong; Yuan Baohua; Shen Chuan; Shi Weijun

    2012-01-01

    The relationship between the acidified acidity and the acid consumption and uranium leaching rate in the process of uranium bioleaching is investigated. Results indicate that higher uranium leaching rate is obtained when the relatively high acidity was applied at beginning. For different minerals, although the original acidity should be different, lower original acidity was not better for shortening leaching period and improving uranium leaching rate. It confirms 30-40 g/L sulfuric acid as the original acidity was more suitable and more than 30 g/ L should be applied if the mineral particle sizes were larger. (authors)

  4. Queensland Mines plant trials with Caro's acid

    International Nuclear Information System (INIS)

    Lucas, G.C.; Fulton, E.J.; Vautier, F.E.; Waters, D.J.; Ring, R.J.

    1983-01-01

    Laboratory leach tests have been carried out to compare the effectiveness of Caro's acid (permonosulphuric acid) as an alternative oxidant to pyrolusite in the leaching of uranium ores. Results demonstrated that Caro's acid reduced acid consumption in leaching and the time required for neutralisation of tailings liquor. The uranium extraction was unaffected by choice of oxidant. A plant trial confirmed that significant savings in acid and lime usage can be achieved under plant conditions. Plant operations also demonstrated that Caro's acid has a number of significant operating advantages over pyrolusite. Queensland Mines Ltd. have recently decided to convert their leaching process from pyrolusite to Caro's acid

  5. Tumor Acidity as Evolutionary Spite

    International Nuclear Information System (INIS)

    Alfarouk, Khalid O.; Muddathir, Abdel Khalig; Shayoub, Mohammed E. A.

    2011-01-01

    Most cancer cells shift their metabolic pathway from a metabolism reflecting the Pasteur-effect into one reflecting the Warburg-effect. This shift creates an acidic microenvironment around the tumor and becomes the driving force for a positive carcinogenesis feedback loop. As a consequence of tumor acidity, the tumor microenvironment encourages a selection of certain cell phenotypes that are able to survive in this caustic environment to the detriment of other cell types. This selection can be described by a process which can be modeled upon spite: the tumor cells reduce their own fitness by making an acidic environment, but this reduces the fitness of their competitors to an even greater extent. Moreover, the environment is an important dimension that further drives this spite process. Thus, diminishing the selective environment most probably interferes with the spite process. Such interference has been recently utilized in cancer treatment

  6. Mine waters: Acidic to circumneutral

    Science.gov (United States)

    Nordstrom, D. Kirk

    2011-01-01

    Acid mine waters, often containing toxic concentrations of Fe, Al, Cu, Zn, Cd, Pb, Ni, Co, and Cr, can be produced from the mining of coal and metallic deposits. Values of pH for acid mine waters can range from –3.5 to 5, but even circumneutral (pH ≈ 7) mine waters can have high concentrations of As, Sb, Mo, U, and F. When mine waters are discharged into streams, lakes, and the oceans, serious degradation of water quality and injury to aquatic life can ensue, especially when tailings impoundments break suddenly. The main acid-producing process is the exposure of pyrite to air and water, which promotes oxidative dissolution, a reaction catalyzed by microbes. Current and future mining should plan for the prevention and remediation of these contaminant discharges by the application of hydrogeochemical principles and available technologies, which might include remining and recycling of waste materials.

  7. Preparation of deuterated succinic acids

    Energy Technology Data Exchange (ETDEWEB)

    Tashiro, Masashi; Tsuzuki, Hirohisa; Goto, Hideyuki; Ogasahara, Shoji; Mataka, Shuntaro (Kyushu Univ., Fukuoka (Japan)); Isobe, Shin-ichiro; Yonemitsu, Tadashi (Kyushu Sangyo Univ., Fukuoka (Japan). Dept. of Industrial Chemistry)

    1991-04-01

    Succinic (2,3-{sup 2}H{sub 2})- and (2,2,3,3-{sup 2}H{sub 4})-acids were prepared from maleic anhydride and dimethyl fumarate, and acetylene dicarboxylic acid and its dimethyl ester by treatment with Cu-Al and Ni-Al alloys in 10% NaOD-D{sub 2}0 in 95% to 100% isotopic purity. The succinic {sup 2}H{sub 4} acid having high isotopic purity was also obtained on the hydrolysis of 1,2-ethanedinitrile with alkaline deuterium oxide. Based on the {sup 1}H({sup 2}H) spectra analysis of N-(o-biphenyl)(2,3-{sup 2}H{sub 2})succinimide, it was elucidated that the Raney alloy reduction with alkaline deuterium oxide proceeds stepwise. (author).

  8. Nitric Acid Poisoning: Case Report

    International Nuclear Information System (INIS)

    Quintero Giraldo, Maria Paulina; Quiceno Calderon, William de Jesus; Melo Arango Catalina

    2011-01-01

    Nitric acid (HNO 3 ) is a corrosive fluid that, when in contact with reducing agents, generates nitrogen oxides that are responsible for inhalation poisoning. We present two cases of poisoning from nitric acid gas inhalation resulting from occupational exposure. Imaging findings were similar in both cases, consistent with adult respiratory distress syndrome (ARDS): bilaterally diffuse alveolar opacities on the chest X-ray and a cobblestone pattern on computed tomography (CT).one of the patients died while the other evolved satisfactorily after treatment with n-acetyl cysteine and mechanical ventilation. The diagnosis of nitric acid poisoning was made on the basis of the history of exposure and the way in which the radiological findings evolved.

  9. Uranium extraction in phosphoric acid

    International Nuclear Information System (INIS)

    Araujo Figueiredo, C. de

    1984-01-01

    Uranium is recovered from the phosphoric liquor produced from the concentrate obtained from phosphorus-uraniferous mineral from Itataia mines (CE, Brazil). The proposed process consists of two extraction cycles. In the first one, uranium is reduced to its tetravalent state and then extracted by dioctylpyrophosphoric acid, diluted in Kerosene. Re-extraction is carried out with concentrated phosphoric acid containing an oxidising agent to convert uranium to its hexavalent state. This extract (from the first cycle) is submitted to the second cycle where uranium is extracted with DEPA-TOPO (di-2-hexylphosphoric acid/tri-n-octyl phosphine oxide) in Kerosene. The extract is then washed and uranium is backextracted and precipitated as commercial concentrate. The organic phase is recovered. Results from discontinuous tests were satisfactory, enabling to establish operational conditions for the performance of a continuous test in a micro-pilot plant. (Author) [pt

  10. Geological aspects of acid deposition

    International Nuclear Information System (INIS)

    Bricker, O.P.

    1984-01-01

    The general pattern of rain falling on the earth and reacting with the materials of the lithosphere (the weathering reactions so familiar to every beginning geology student) began soon after the earth was formed and has continued to the present. Anthropogenic additions to the natural acidic components of the atmosphere have increased since the time of the industrial revolution until they now rival or exceed those of the natural system. The severity of the environmental perturbations caused by these anthropogenic additions to the atmosphere has become a hotly debated topic in scientific forums and in the political arena. The six chapters in this book address various aspects of the acid deposition phenomenon from a geological perspective. It is hoped that the geological approach will be useful in bringing the problem more clearly into focus and may shed light on the geochemical processes that modify the chemical composition of acid deposition after it encounters and reacts with the materials of the lithosphere

  11. Identifying a base in a nucleic acid

    Science.gov (United States)

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2005-02-08

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  12. Salicylic acid-independent plant defence pathways

    OpenAIRE

    Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are independent of salicylic acid. Evidence is emerging that jasmonic acid and ethylene play key roles in these salicylic acid-independent pathways. Cross-talk between the salicylic acid-dependent and the salicy...

  13. Glutamic acid as anticancer agent: An overview

    OpenAIRE

    Dutta, Satyajit; Ray, Supratim; Nagarajan, K.

    2013-01-01

    The objective of the article is to highlight various roles of glutamic acid like endogenic anticancer agent, conjugates to anticancer agents, and derivatives of glutamic acid as possible anticancer agents. Besides these emphases are given especially for two endogenous derivatives of glutamic acid such as glutamine and glutamate. Glutamine is a derivative of glutamic acid and is formed in the body from glutamic acid and ammonia in an energy requiring reaction catalyzed by glutamine synthase. I...

  14. 21 CFR 186.1316 - Formic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Formic acid. 186.1316 Section 186.1316 Food and... Substances Affirmed as GRAS § 186.1316 Formic acid. (a) Formic acid (CH2O2, CAS Reg. No. 64-18-6) is also referred to as methanoic acid or hydrogen carboxylic acid. It occurs naturally in some insects and is...

  15. 21 CFR 184.1021 - Benzoic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Benzoic acid. 184.1021 Section 184.1021 Food and... Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7H6O2), occurring in nature in free and combined forms. Among the foods in which benzoic acid occurs...

  16. 21 CFR 184.1065 - Linoleic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Linoleic acid. 184.1065 Section 184.1065 Food and... Substances Affirmed as GRAS § 184.1065 Linoleic acid. (a) Linoleic acid ((Z, Z)-9, 12-octadecadienoic acid (C17H31COOH) (CAS Reg. No. 60-33-3)), a straight chain unsaturated fatty acid with a molecular weight of 280.5...

  17. Fatty acid composition and amino acid profile of two freshwater ...

    African Journals Online (AJOL)

    The proximate, fatty and amino acids composition of two commercially important freshwater fish species Clarias gariepinus and Tilapia zillii. purchased from local fishermen in two landing sites in Lagos State, Nigeria were determined. Live specimens of C. gariepinus were purchased while samples of T. zillii were stored in ...

  18. Nitrous Acid as an Oxidant in Acidic Media

    Science.gov (United States)

    1979-09-25

    current work is the account of Ogsts and Sawski3 who studied the oxidation of benzyl ethers at 90C in acidic, aqueous dioxane. They found an increase in...and G. Tobin, Chem. Com., 180 (1978); (b) J. Hoggett , R. Moodie, and K. Schofield, Chem. Comm., 605 (1969). 15. (a) B. Challis and A. Lawson. J. Chem

  19. Kinetics of oxidation of acidic amino acids by sodium N ...

    Indian Academy of Sciences (India)

    Unknown

    BAB) has been carried out in aqueous HClO4 medium at 30°C. The rate shows first- ... amino acids by chloramines 7,8 while, little attention has been focused on ... in glass-stoppered pyrex boiling tubes whose outer surface was coated ... BAB in a measured aliquot (5 ml each) of the reaction mixture at different intervals of.

  20. Amino acids analysis during lactic acid fermentation by single strain ...

    African Journals Online (AJOL)

    L. salivarius alone showed relatively good assimilation of various amino acids that existed at only a little amounts in MRS media (Asn, Asp, Cit, Cys, Glu, His, Lys, Orn, Phe, Pro, Tyr, Arg, Ile, Leu, Met, Ser, Thr, Trp and Val), whereas Ala and Gly accumulated in L. salivarius cultures. P. acidilactici, in contrast, hydrolyzed the ...

  1. Fatty acids and amino acids contents in Scomber scombrus fillets ...

    African Journals Online (AJOL)

    Proximate composition, fats and amino acids of Atlantic Mackerel fillets (Scomber scombrus) from the South East of Tunisia in different seasons, were analyzed in order to assess nutritive characteristics of this species. Samples were collected monthly from Zarzis fishing port located in the South-East of Tunisia. Total fats and ...

  2. Boronic acid-based autoligation of nucleic acids

    DEFF Research Database (Denmark)

    Barbeyron, R.; Vasseur, J.-J.; Smietana, M.

    2013-01-01

    Abstract: The development of synthetic systems displaying dynamic and adaptive characteristics is a formidable challenge with wide applications from biotechnology to therapeutics. Recently, we described a dynamic and programmable nucleic acid-based system relying on the formation of reversible bo....... Evidence suggests that geometric and steric factors are key features for controlling the equilibria. Graphical Abstract: [Figure not available: see fulltext.]...

  3. Kinetics of oxidation of acidic amino acids by sodium N

    Indian Academy of Sciences (India)

    Asp)) by sodium N-bromobenzenesulphonamide (bromamine-B or BAB) has been carried out in aqueous HClO4 medium at 30°C. The rate shows firstorder dependence each on [BAB]o and [amino acid]o and inverse first-order on [H+]. At [H+] > ...

  4. Formic acid assisted hydrogenation of levulinic acid to ...

    Indian Academy of Sciences (India)

    Muppala Ashokraju

    2018-02-07

    Feb 7, 2018 ... to γ-valerolactone over ordered mesoporous Cu/Fe2O3 catalyst ... Compared to the direct use of biomass as fuel, its con- ... still room for the design and development of an efficient. 1 ... advantages no necessity of separation of levulinic acid ... of catalyst was placed in a quartz reactor and pre-treated in.

  5. Effect of para-chlorophenoxyacetic acid on acid invertase gene ...

    African Journals Online (AJOL)

    Tomato cv. Liaoyuanduoli (Solanum lycopersicum) plants were cultivated in a greenhouse to allow sampling of the second fruit in the first cluster and comparison with tomato fruit that developed following para-chlorophenoxyacetic acid (PCPA) treatment. Sugar content, activities of sugar related enzymes and the effects of ...

  6. Serum n-3 Tetracosapentaenoic Acid and Tetracosahexaenoic Acid Increase Following Higher Dietary α-Linolenic Acid but not Docosahexaenoic Acid.

    Science.gov (United States)

    Metherel, Adam H; Domenichiello, Anthony F; Kitson, Alex P; Lin, Yu-Hong; Bazinet, Richard P

    2017-02-01

    n-3 Tetracosapentaenoic acid (24:5n-3, TPAn-3) and tetracosahexaenoic acid (24:6n-3, THA) are believed to be important intermediates to docosahexaenoic acid (DHA, 22:6n-3) synthesis. The purpose of this study is to report for the first time serum concentrations of TPAn-3 and THA and their response to changing dietary α-linolenic acid (18:3n-3, ALA) and DHA. The responses will then be used in an attempt to predict the location of these fatty acids in relation to DHA in the biosynthetic pathway. Male Long Evans rats (n = 6 per group) were fed either a low (0.1% of total fatty acids), medium (3%) or high (10%) ALA diet with no added DHA, or a low (0%), medium (0.2%) or high (2%) DHA diet with a background of 2% ALA for 8 weeks post-weaning. Serum n-3 and n-6 polyunsaturated fatty acid (PUFA) concentrations (nmol/mL ± SEM) were determined by gas chromatography-mass spectrometry. Serum THA increases from low (0.3 ± 0.1) to medium (5.8 ± 0.7) but not from medium to high (4.6 ± 0.9) dietary ALA, while serum TPAn-3 increases with increasing dietary ALA from 0.09 ± 0.04 to 0.70 ± 0.09 to 1.23 ± 0.14 nmol/mL. Following DHA feeding, neither TPAn-3 or THA change across all dietary DHA intake levels. Serum TPAn-3 demonstrates a similar response to dietary DHA. In conclusion, this is the first study to demonstrate that increases in dietary ALA but not DHA increase serum TPAn-3 and THA in rats, suggesting that both fatty acids are precursors to DHA in the biosynthetic pathway.

  7. Acid precipitation and forest vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Tamm, C O; Cowling, E B

    1977-04-01

    Effects of acidic precipitation on forest vegetation may be classified as being either direct or indirect. Among the most important direct effects are damage to protective cuticular layers, interference with normal functioning of guard cells, poisoning of plant cells after diffusion of acidic substances through stomata or cuticle and interference with reproductive processes. Indirect effects include accelerated leaching of substances from foliar organs, increased susceptibility to drought and other environmental stress factors, and alteration of symbiotic associations and host-parasite interactions. The potential importance of nutrient uptake through foliage and the need to understand atmosphere-plant-soil interactions are stressed.

  8. Acid Sulfate Alteration on Mars

    Science.gov (United States)

    Ming, D. W.; Morris, R. V.

    2016-01-01

    A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Acid sulfate alteration has been identified at all three landing sites visited by NASA rover missions (Spirit, Opportunity, and Curiosity). Spirit landed in Gusev crater in 2004 and discovered Fe-sulfates and materials that have been extensively leached by acid sulfate solutions. Opportunity landing on the plains of Meridiani Planum also in 2004 where the rover encountered large abundances of jarosite and hematite in sedimentary rocks. Curiosity landed in Gale crater in 2012 and has characterized fluvial, deltaic, and lacustrine sediments. Jarosite and hematite were discovered in some of the lacustrine sediments. The high elemental abundance of sulfur in surface materials is obvious evidence that sulfate has played a major role in aqueous processes at all landing sites on Mars. The sulfate-rich outcrop at Meridiani Planum has an SO3 content of up to 25 wt.%. The interiors of rocks and outcrops on the Columbia Hills within Gusev crater have up to 8 wt.% SO3. Soils at both sites generally have between 5 to 14 wt.% SO3, and several soils in Gusev crater contain around 30 wt.% SO3. After normalization of major element compositions to a SO3-free basis, the bulk compositions of these materials are basaltic, with a few exceptions in Gusev crater and in lacustrine mudstones in Gale crater. These observations suggest that materials encountered by the rovers were derived from basaltic precursors by acid sulfate alteration under nearly isochemical conditions (i.e., minimal leaching). There are several cases, however, where acid sulfate alteration minerals (jarosite and hematite) formed in open hydrologic systems, e.g., in Gale crater lacustrine mudstones. Several hypotheses have been suggested for the

  9. Acid-functionalized polyolefin materials and their use in acid-promoted chemical reactions

    Science.gov (United States)

    Oyola, Yatsandra; Tian, Chengcheng; Bauer, John Christopher; Dai, Sheng

    2016-06-07

    An acid-functionalized polyolefin material that can be used as an acid catalyst in a wide range of acid-promoted chemical reactions, wherein the acid-functionalized polyolefin material includes a polyolefin backbone on which acid groups are appended. Also described is a method for the preparation of the acid catalyst in which a precursor polyolefin is subjected to ionizing radiation (e.g., electron beam irradiation) of sufficient power and the irradiated precursor polyolefin reacted with at least one vinyl monomer having an acid group thereon. Further described is a method for conducting an acid-promoted chemical reaction, wherein an acid-reactive organic precursor is contacted in liquid form with a solid heterogeneous acid catalyst comprising a polyolefin backbone of at least 1 micron in one dimension and having carboxylic acid groups and either sulfonic acid or phosphoric acid groups appended thereto.

  10. Enzymatic synthesis of 11C-pyruvic acid and 11C-L-lactic acid

    International Nuclear Information System (INIS)

    Cohen, M.B.; Spolter, L.; Chang, C.C.; Cook, J.S.; Macdonald, N.S.

    1980-01-01

    L-Lactic acid is formed as the end product of glycolysis under anaerobic conditions in all cells, but this reaction is of special significance in the myocardium. L-Lactic acid is reversibly formed from and is in equilibrium with myocardial pyruvic acid, which is its sole metabolic pathway. 11 C-Pyruvic acid is synthesized from 11 C carbon dioxide using pyruvate-ferredoxin oxidoreductase and coenzymes. The 11 C-pyruvic acid is then converted to 11 -L-lactic acid by lactic acid dehydrogenase. The availability of 11 C-pyruvic acid and 11 C-L-lactic acid will permit the in vivo investigation of lactate metabolism. (author)

  11. Citric Acid Passivation of Stainless Steel

    Science.gov (United States)

    Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

    2009-01-01

    Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

  12. Fatty acid profile of Albizia lebbeck and Albizia saman seed oils: Presence of coronaric acid

    Science.gov (United States)

    In this work, the fatty acid profiles of the seed oils of Albizia lebbeck and Albizia saman (Samanea saman) are reported. The oils were analyzed by GC, GC-MS, and NMR. The most prominent fatty acid in both oils is linoleic acid (30-40%), followed by palmitic acid and oleic acid for A. lebbeck and ol...

  13. Determination of acetylsalicylic acid and salicylic acid in foods, using HPLC with fluorescence detection.

    NARCIS (Netherlands)

    Venema, D.P.; Hollman, P.C.H.; Janssen, P.L.T.M.K.; Katan, M.B.

    1996-01-01

    We developed a specific and sensitive HPLC method with fluorescence detection for the determination of free acetylsalicylic acid, free salicylic acid, and free salicylic acid plus salicylic acid after alkaline hydrolysis (free-plus-bound) in foods. Acetylsalicylic acid was detected after postcolumn

  14. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid amine condensate... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts. (a... a fatty acid amine condensate, polycarboxylic acid salts. (PMN P-92-445) is subject to reporting...

  15. Method for production of petroselinic acid and OMEGA12 hexadecanoic acid in transgenic plants

    Science.gov (United States)

    Ohlrogge, John B.; Cahoon, Edgar B.; Shanklin, John; Somerville, Christopher R.

    1995-01-01

    The present invention relates to a process for producing lipids containing the fatty acid petroselinic acid in plants. The production of petroselinic acid is accomplished by genetically transforming plants which do not normally accumulate petroselinic acid with a gene for a .omega.12 desaturase from another species which does normally accumulate petroselinic acid.

  16. 21 CFR 172.350 - Fumaric acid and salts of fumaric acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Fumaric acid and salts of fumaric acid. 172.350... HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid and its calcium, ferrous, magnesium, potassium, and sodium salts may be safely used...

  17. Coupling of subcritical methanol with acidic ionic liquids for the acidity reduction of naphthenic acids

    Directory of Open Access Journals (Sweden)

    Zafar Faisal

    2017-09-01

    Full Text Available The presence of naphthenic acids (NAs in crude oil is the major cause of corrosion in the refineries and its processing equipment. The goal of this study is to reduce the total acid number (TAN of NAs by treating them with subcritical methanol in the presence of acidic ionic liquid (AIL catalysts. Experiments were carried out in an autoclave batch reactor and the effect of different reaction parameters was investigated. It was observed that TAN reduction was positively dependent on the temperature and concentration of the AIL whereas excess of methanol has a negative effect. Approximately 90% TAN reduction was achieved under the optimized reaction conditions using [BMIM]HSO4 as catalyst. It was also perceived from the experimental results that the AILs with longer alkyl chain exhibited higher catalytic activity. The activity and stability of AIL showed that they can be promising catalyst to esterify NAs under subcritical methanol.

  18. Tritium-labelled abscisic acid

    International Nuclear Information System (INIS)

    Pluciennik, H.; Michalski, L.

    1991-01-01

    A simple method for the preparation of biologically active abscisic acid (growth inhibiting plant hormone) labelled with tritium is described. The product obtained has a specific radioactivity of 1.12 GBq mmol -1 : the yield is about 60% as compared to the initial amount of the substance used. (author) 7 refs.; 2 figs

  19. Toward Sustainable Amino Acid Production.

    Science.gov (United States)

    Usuda, Yoshihiro; Hara, Yoshihiko; Kojima, Hiroyuki

    Because the global amino acid production industry has been growing steadily and is expected to grow even more in the future, efficient production by fermentation is of great importance from economic and sustainability viewpoints. Many systems biology technologies, such as genome breeding, omics analysis, metabolic flux analysis, and metabolic simulation, have been employed for the improvement of amino acid-producing strains of bacteria. Synthetic biological approaches have recently been applied to strain development. It is also important to use sustainable carbon sources, such as glycerol or pyrolytic sugars from cellulosic biomass, instead of conventional carbon sources, such as glucose or sucrose, which can be used as food. Furthermore, reduction of sub-raw substrates has been shown to lead to reduction of environmental burdens and cost. Recently, a new fermentation system for glutamate production under acidic pH was developed to decrease the amount of one sub-raw material, ammonium, for maintenance of culture pH. At the same time, the utilization of fermentation coproducts, such as cells, ammonium sulfate, and fermentation broth, is a useful approach to decrease waste. In this chapter, further perspectives for future amino acid fermentation from one-carbon compounds are described.

  20. Uric acid in multiple sclerosis

    NARCIS (Netherlands)

    Koch, M; De Keyser, J

    Peroxynitrite, a reactive oxidant formed by the reaction of nitric oxide with superoxide at sites of inflammation in multiple sclerosis (MS), is capable of damaging tissues and cells. Uric acid, a natural scavenger of peroxynitrite, reduces inflammatory demyelination in experimental allergic

  1. 2-(3-Hydroxybenzylaminoacetic acid

    Directory of Open Access Journals (Sweden)

    Li-Hua Zhi

    2011-07-01

    Full Text Available There are two independent 2-(3-hydroxybenzylaminoacetic acid molecules, C9H11NO3, in the asymmetric unit of the title compound. The dihedral angle between the benzene rings of the two independent molecules is 58.12 (4°. The crystal packing is stablized by intermolecular O—H...O and N—H...O hydrogen bonds.

  2. Recovering uranium from phosphoric acid

    International Nuclear Information System (INIS)

    Abodishish, H.A.; Ritchey, R.W.

    1982-01-01

    Precipitation of Fe 3 HN 4 H 8 (PO 4 ) 6 is prevented in the second cycle extractor, in a two cycle uranium recovery process, by washing ammonia laden organic solvent stream, from the second cycle stripper, with first cycle raffinate iron stream containing phosphoric acid, prior to passing the solvent stream into the second cycle extractor. (author)

  3. Biodegradable poly(lactic acid)

    Indian Academy of Sciences (India)

    The fabrication of biodegradable poly(lactic acid) (PLA) microspheres containing total alkaloids of Caulis sinomenii was investigated. The formation, diameter, morphology and properties of the microspheres were characterized using Fourier transform infrared spectroscopy (FT–IR), laser particle size analyser and scanning ...

  4. Back to acid soil fields

    NARCIS (Netherlands)

    Carvalho, Geraldo; Schaffert, Robert Eugene; Malosetti Zunin, Marcos; Eeuwijk, van Fred

    2016-01-01

    Aluminum (Al) toxicity damages plant roots and limits crop production on acid soils, which comprise up to 50% of the world's arable lands. A major Al tolerance locus on chromosome 3, AltSB, controls aluminum tolerance in sorghum [Sorghum bicolor (L.) Moench] via SbMATE, an Al-activated plasma

  5. Radiolabeled derivatives of folic acid

    International Nuclear Information System (INIS)

    1980-01-01

    Derivatives of folic acid are described, in which the α-carboxyl group is substituted with an amino compound having an aromatic or heterocyclic ring substituent which is capable of being radiolabelled. Particularly mentioned as a radiolabel is 125 I. (author)

  6. An assessment of acid fog

    International Nuclear Information System (INIS)

    Lipfert, F.W.

    1992-01-01

    Airborne particles have long been associated with adverse effects on public health, begin with the notorious air pollution disasters of several decades ago. Although H 2 SO 4 was identified early on as a potential causal factors during these episodes (in part because of concern for potential health effects of particle acidity per se has intensified only recently. Most of the recent aerometric research in the US on acid fog has focused on the ability of clouds and fog to deliver acidity to vegetation and ecosystems. Strong acids are characterized chemically by their pH or H + concentration. For fog, concentrations are referred to the droplet liquid content; for other (i.e., ''clear air'') aerosols, to the volume of air sampled. A useful measure of the relationship between aerosol and fog is obtained by comparing their mass concentrations on the basis of the same volume of air, by multiplying fogwater concentrations by liquid water content (LWC). This paper reviews fog measurement capability, physical properties and chemistry, and presents a simple urban airshed model which is used to simulate the evolution of fog and aerosol concentrations under urban stagnation conditions

  7. An assessment of acid fog

    Energy Technology Data Exchange (ETDEWEB)

    Lipfert, F.W.

    1992-12-31

    Airborne particles have long been associated with adverse effects on public health, begin with the notorious air pollution disasters of several decades ago. Although H{sub 2}SO{sub 4} was identified early on as a potential causal factors during these episodes (in part because of concern for potential health effects of particle acidity per se has intensified only recently. Most of the recent aerometric research in the US on acid fog has focused on the ability of clouds and fog to deliver acidity to vegetation and ecosystems. Strong acids are characterized chemically by their pH or H{sup +} concentration. For fog, concentrations are referred to the droplet liquid content; for other (i.e., ``clear air``) aerosols, to the volume of air sampled. A useful measure of the relationship between aerosol and fog is obtained by comparing their mass concentrations on the basis of the same volume of air, by multiplying fogwater concentrations by liquid water content (LWC). This paper reviews fog measurement capability, physical properties and chemistry, and presents a simple urban airshed model which is used to simulate the evolution of fog and aerosol concentrations under urban stagnation conditions.

  8. Endocrine functions of bile acids

    NARCIS (Netherlands)

    Houten, Sander M.; Watanabe, Mitsuhiro; Auwerx, Johan

    2006-01-01

    Bile acids (BAs), a group of structurally diverse molecules that are primarily synthesized in the liver from cholesterol, are the chief components of bile. Besides their well-established roles in dietary lipid absorption and cholesterol homeostasis, it has recently emerged that BAs are also

  9. Antibiofilm Properties of Acetic Acid

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup

    2014-01-01

    Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the inf......Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal...... of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram......-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms....

  10. Structure of acid-stable carmine.

    Science.gov (United States)

    Sugimoto, Naoki; Kawasaki, Yoko; Sato, Kyoko; Aoki, Hiromitsu; Ichi, Takahito; Koda, Takatoshi; Yamazaki, Takeshi; Maitani, Tamio

    2002-02-01

    Acid-stable carmine has recently been distributed in the U.S. market because of its good acid stability, but it is not permitted in Japan. We analyzed and determined the structure of the major pigment in acid-stable carmine, in order to establish an analytical method for it. Carminic acid was transformed into a different type of pigment, named acid-stable carmine, through amination when heated in ammonia solution. The features of the structure were clarified using a model compound, purpurin, in which the orientation of hydroxyl groups on the A ring of the anthraquinone skeleton is the same as that of carminic acid. By spectroscopic means and the synthesis of acid-stable carmine and purpurin derivatives, the structure of the major pigment in acid-stable carmine was established as 4-aminocarminic acid, a novel compound.

  11. Solid-state actinide acid phosphites from phosphorous acid melts

    International Nuclear Information System (INIS)

    Oh, George N.; Burns, Peter C.

    2014-01-01

    The reaction of UO 3 and H 3 PO 3 at 100 °C and subsequent reaction with dimethylformamide (DMF) produces crystals of the compound (NH 2 (CH 3 ) 2 )[UO 2 (HPO 2 OH)(HPO 3 )]. This compound crystallizes in space group P2 1 /n and consists of layers of uranyl pentagonal bipyramids that share equatorial vertices with phosphite units, separated by dimethylammonium. In contrast, the reaction of phosphorous acid and actinide oxides at 210 °C produces a viscous syrup. Subsequent dilution in solvents and use of standard solution-state methods results in the crystallization of two polymorphs of the actinide acid phosphites An(HPO 2 OH) 4 (An=U, Th) and of the mixed acid phosphite–phosphite U(HPO 3 )(HPO 2 OH) 2 (H 2 O)·2(H 2 O). α- and β-An(HPO 2 OH) 4 crystallize in space groups C2/c and P2 1 /n, respectively, and comprise a three-dimensional network of An 4+ cations in square antiprismatic coordination corner-sharing with protonated phosphite units, whereas U(HPO 3 )(HPO 2 OH) 2 (H 2 O) 2 ·(H 2 O) crystallizes in a layered structure in space group Pbca that is composed of An 4+ cations in square antiprismatic coordination corner-sharing with protonated phosphites and water ligands. We discuss our findings in using solid inorganic reagents to produce a solution-workable precursor from which solid-state compounds can be crystallized. - Graphical abstract: Reaction of UO 3 and H 3 PO 3 at 100 °C and subsequent reaction with DMF produces crystals of (NH 2 (CH 3 ) 2 )[UO 2 (HPO 2 OH)(HPO 3 )] with a layered structure. Reaction of phosphorous acid and actinide oxides at 210 °C produces a viscous syrup and further solution-state reactions result in the crystallization of the actinide acid phosphites An(HPO 2 OH) 4 (An=U, Th), with a three-dimensional network structure, and the mixed acid phosphite–phosphite U(HPO 3 )(HPO 2 OH) 2 (H 2 O) 2 ·(H 2 O) with a layered structure. - Highlights: • U(VI), U(IV) and Th(IV) phosphites were synthesized by solution

  12. Amino acid metabolism in plant leaf, 1

    International Nuclear Information System (INIS)

    Ito, Osamu; Kumazawa, Kikuo

    1977-01-01

    14C-labelled sodium bicarbonate and 15N-labelled ammonium sulfate were simultaneously vacuum-infiltrated into detached sunflower leaves, and the incorporation of 14C and 15N into free amino acids was chased during 60-min period in the light and in the dark. In the light, the 14C specific activity of aspartic acid, alanine, serine and glycine rapidly increased for 5 min and thereafter decreased. On the other hand, that of glutamic acid continued to increase slowly during the entire 60-min period. In the dark, aspartic acid most actively incorporated 14C. The difference of changes in 14C specific activity between glutamic acid and other amino acids was also observed in the dark as in the light. These results suggest that the carbon skeleton of glutamic acid is synthesized from aspartic acid, alanine, serine and glycine. 15N content of glutamine was the highest of all amino acids investigated in the light, and it was followed by glutamic acid, alanine, aspartic acid, serine and glycine, in this order. In the dark, 15N content of glutamic acid fell remarkably and was lower than that of alanine up to 5 min. From these 15N tracer experiments, it is suggested that the incorporation of ammonium into glutamic acid is strictly dependent on light and that alanine incorporates ammonium by the direct animation besides the transamination from glutamic acid. (auth.)

  13. Crystal growth and physical characterization of picolinic acid cocrystallized with dicarboxylic acids

    Science.gov (United States)

    Somphon, Weenawan; Haller, Kenneth J.

    2013-01-01

    Pharmaceutical cocrystals are multicomponent materials containing an active pharmaceutical ingredient with another component in well-defined stoichiometry within the same unit cell. Such cocrystals are important in drug design, particularly for improving physicochemical properties such as solubility, bioavailability, or chemical stability. Picolinic acid is an endogenous metabolite of tryptophan and is widely used for neuroprotective, immunological, and anti-proliferative effects within the body. In this paper we present cocrystallization experiments of a series of dicarboxylic acids, oxalic acid, succinic acid, DL-tartaric acid, pimelic acid, and phthalic acid, with picolinic acid. Characterization by FT-IR and Raman spectroscopy, DSC and TG/DTG analysis, and X-ray powder diffraction show that new compounds are formed, including a 1:1 picolinium tartrate monohydrate, a 2:1 monohydrate adduct of picolinic acid and oxalic acid, and a 2:1 picolinic acid-succinic acid monohydrate cocrystal.

  14. Molybdenum-containing acidic catalysts to convert cellulosic biomass to glycolic acid

    KAUST Repository

    Han, Yu; Zhang, Jizhe; Liu, Xin

    2014-01-01

    Embodiments of the present invention include methods and compositions related to catabolic conversion of cellulosic biomass to glycolic acid using molybdenum-containing acidic catalysts. The invention includes the use of heteropoly and isopoly acids

  15. Profile of Fatty Acids, Amino Acids, Carotenoid Total, and α-Tocopherol from Flying Fish Eggs

    Directory of Open Access Journals (Sweden)

    Aulia Azka

    2015-12-01

    Full Text Available Flying fish are found in waters of eastern Indonesia, which until now is still limited informationabout nutritional content. The purpose of this research was determine the composition offatty acids, amino acids, total carotenoids, α-tocopherol flying fish eggs (Hyrundicthys sp..The composition of fatty acid was measured by gas chromatography (GC, while amino acids,total carotenoids, α-tocopherol was measured by High performanced Liquid Chromatography(HPLC. Egg contained 22 fatty acids such as saturated fatty acid 29.71%, monounsaturated fattyacid 7.86%, and polysaturated fatty acid 13.64%. The result showed that eggs flying fish contained17 amino acids, such as essential amino acid 14.96% and non-essential amino acids 20.27%. Eggscontained a total carotenoid of 245.37 ppm. α-tocopherol content of flying fish eggs by 1.06 ppm.Keywords: Amino acids, carotenoid total, fatty acid, flying fish egg, α-tocopherol

  16. Role of sialic acid in synaptosomal transport of amino acid transmitters

    International Nuclear Information System (INIS)

    Zaleska, M.M.; Erecinska, M.

    1987-01-01

    Active, high-affinity, sodium-dependent uptake of [ 14 C]-aminobutyric acid and of the acidic amino acid D-[ 3 H]-aspartate was inhibited by pretreatment of synaptosomes with neuraminidase from Vibrio cholerae. Inhibition was of a noncompetitive type and was related to the amount of sialic acid released. The maximum accumulation ratios of both amino acids (intracellular [amino acid]/extracellular [amino acid]) remained largely unaltered. Treatment with neuraminidase affected neither the synaptosomal energy levels nor the concentration of internal potassium. It is suggested that the γ-aminobutyric acid and acidic amino acid transporters are glycosylated and that sialic acid is involved in the operation of the carrier proteins directly and not through modification of driving forces responsible for amino acid uptake

  17. Effect of acetic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

    Science.gov (United States)

    Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2014-09-01

    An integrated citric acid-methane fermentation process was proposed to solve the problem of extraction wastewater in citric acid fermentation process. Extraction wastewater was treated by anaerobic digestion and then recycled for the next batch of citric acid fermentation to eliminate wastewater discharge and reduce water resource consumption. Acetic acid as an intermediate product of methane fermentation was present in anaerobic digestion effluent. In this study, the effect of acetic acid on citric acid fermentation was investigated and results showed that lower concentration of acetic acid could promote Aspergillus niger growth and citric acid production. 5-Cyano-2,3-ditolyl tetrazolium chloride (CTC) staining was used to quantify the activity of A. niger cells, and the results suggested that when acetic acid concentration was above 8 mM at initial pH 4.5, the morphology of A. niger became uneven and the part of the cells' activity was significantly reduced, thereby resulting in deceasing of citric acid production. Effects of acetic acid on citric acid fermentation, as influenced by initial pH and cell number in inocula, were also examined. The result indicated that inhibition by acetic acid increased as initial pH declined and was rarely influenced by cell number in inocula.

  18. Incorporation and distribution of dihomo-gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid in cultured human keratinocytes

    International Nuclear Information System (INIS)

    Punnonen, K.; Puustinen, T.; Jansen, C.T.

    1986-01-01

    Human keratinocytes in culture were labelled with 14 C-dihomo-gamma-linolenic acid, 14 C-arachidonic acid or 14 C-eicosapentaenoic acid. All three eicosanoid precursor fatty acids were effectively incorporated into the cells. In phospholipids most of the radioactivity was recovered, in neutral lipids a substantial amount, and as free unesterified fatty acids only a minor amount. Most of the radioactivity was found in phosphatidylethanolamine which was also the major phospholipid as measured by phosphorous assay. The incorporation of dihomo-gamma-linolenic acid and arachidonic acid into lipid subfractions was essentially similar. Eicosapentaenoic acid was, however, much less effectively incorporated into phosphatidylinositol + phosphatidylserine and, correspondingly, more effectively into triacylglycerols as compared to the two other precursor fatty acids. Once incorporated, the distribution of all three precursor fatty acids was relatively stable, and only minor amounts of fatty acids were released into the culture medium during short term culture (two days). Our study demonstrates that eicosanoid precursor fatty acids are avidly taken up by human keratinocytes and esterified into membrane lipids. The clinical implication of this finding is that dietary manipulations might be employed to cause changes in the fatty acid composition of keratinocytes

  19. Classical bile acids in animals, beta-phocaecholic acid in ducks.

    Science.gov (United States)

    Jirsa, M; Klinot, J; Klinotová, E; Ubik, K; Kucera, K

    1989-01-01

    1. Bile samples of different animals were analysed and the percentage content of classical bile acids was determined. 2. Herbivorous birds mostly excreted a large proportion of chenodeoxycholic acid. 3. The anteater (Myrmecophaga tridactyla) excreted deoxycholic acid most probably as a primary bile acid. 4. In the bile of ducks (Anas platyrhynchos) a large amount of (23R)3 alpha, 7 alpha, 23-trihydroxy-5 beta-cholan-24-oic acid (beta-phocaecholic acid) was found.

  20. Bioisosteric modifications of 2-arylureidobenzoic acids

    DEFF Research Database (Denmark)

    Valgeirsson, Jon; Nielsen, Elsebet O; Peters, Dan

    2004-01-01

    2-Arylureidobenzoic acids (AUBAs) have recently been presented as the first series of selective noncompetitive GluR5 antagonists. In this paper we have modified the acidic moiety of the AUBAs by introducing different acidic and neutral groups, and similarly, we have replaced the urea linker...... of the AUBAs with other structurally related linkers. Replacing the acid with neutral substituents led to inactive compounds in all instances, showing that an acidic moiety is necessary for activity. Replacing the carboxylic moiety in 2a with a sulfonic acid (5c) or a tetrazole ring (5d) improved the potency...