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Sample records for boric acids

  1. Boric acid concentration monitoring

    International Nuclear Information System (INIS)

    Kysela, J.; Mickal, V.; Racek, J.

    1978-01-01

    Boric acid concentration was measured by thermal neutron absorption in the study of the boric acid sorption and desorption curves on an anion exchange resin. Ra-Be 18.5 GBq and Am-Be 111 GBq sources and water as a moderator were used. The SNM 12 cylindrical corona detector with 10 B placed in the middle of the measuring cell was used for neutron flux measurement. The HP 9600 E computer system was used for measured data collection and evaluation. (Ha)

  2. 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

  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. 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

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

    Science.gov (United States)

    Erdemir, A.

    1995-07-11

    Lubricating compositions are disclosed 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.

  6. 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.

  7. 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 ...

  8. 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

  9. Effect of Chemical Additives in Sump on Boric Acid Solubility

    International Nuclear Information System (INIS)

    Luo, Hu; Kim, Young Soo; No, Hee Cheon

    2007-01-01

    Boric acid precipitation, which happens in the pressurized water reactor core during post-LOCA long-term cooling period, could adhere to fuel rod surfaces and, as a result, block the fuel assembly cooling channels. Deposition of boric acid and other impurities on the fuel rods will increase thermal resistance, and then induce fuel temperature to exceed its safety limit, finally causes reactor core damage or meltdown. Therefore, recently, the boric acid precipitation issue was raised by NRC when nuclear power plants in USA, for example, Waterford EPU, applied for power uprate licenses. NRC highlighted boric acid precipitation as a generic issue due to non-conservatism in vendor's model in 2005. Also the Westinghouse Owners Group held meetings to discuss the methodology to avoid boric acid precipitation in the current PWR nuclear power plants. Until now there is no database for evaluating the properties of a boric acid-water mixture, together with chemical additives, such as Sodium Hydroxide (NaOH), Tri-sodium Phosphate (Na 3 PO 4 ) and fiberglass, being added from the containment sump, when the concentration is close to the solubility limit. Therefore, this study investigated boric acid solubility when boric acid is mixed with NaOH, Na 3 PO 4 and other chemical additives. Another purpose of this study is to determine the relationship between boric acid solubility and the effects of chemical additives, boric acid volatility, boiling phenomenon, etc. The empirical equation of boric acid solubility in the mixture solution is deduced from experiment results and chemical dynamics theories

  10. 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.

  11. Boric acid extraction from Kara-Bogaz-Gol brines

    International Nuclear Information System (INIS)

    Putnin', A.Ya.; Shvarts, E.M.; Tel'zhenskaya, P.N.; Sennikova, L.M.; Kalve, I.A.

    1991-01-01

    Conditions of boron extraction in the form of boric acid from the Kara-Bogaz-Gol saline waters and industrial brines were studied. It is shown that the mixture of n.-1.3-diols-C 9 -C 11 can be used for boron isolation from the brines mentioned in case of their complex reprocessing. The degree of boric acid extraction increases considerably with an increase in the medium acidity

  12. 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

  13. 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…

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

    Science.gov (United States)

    Soltani, Motahareh; Shetab-Boushehri, Seyed F; Shetab-Boushehri, Seyed V

    2016-08-01

    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. 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. Activated charcoal significantly reduced the volume of released gas (P poisoning.

  15. 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

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

    Indian Academy of Sciences (India)

    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. Keywords. Multicomponent reaction; amidoalkyl naphthol; boric acid; catalyst; ...

  17. 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...

  18. 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

  19. Aqueous boric acid injection control device in nuclear power plants

    International Nuclear Information System (INIS)

    Takami, Isao; Teranishi, Susumu.

    1980-01-01

    Purpose: To properly control the boron density in coolants by the proper control of the flow rate of aqueous boric acid injected into a coolant system in a BWR type nuclear reactor. Constitution: A volume control tank is communicated to a cooling system and further connected by way of an aqueous boric acid injection pipe with a mixer which is then connected with a pure water supply device and a storage device for high density aqueous boric acid by way of feed pipes respectively. A level detector is disposed to the control tank and flow rate detectors are disposed to each of the feed pipes and the injection pipe. The feed pipes are provided with flow control valves respectively. The control valves are controlled from a valve controller connected to each of the detectors by way of a central instruction device. This eliminates the provision of aqueous boric acid solutions at various concentrations and enables proper control for the boron concentration in the cooling system. (Furukawa, Y.)

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

    African Journals Online (AJOL)

    Mgina

    patterns of recurrent oral candidiasis in. HIV-positive patients. J. Infect. Dis. 168: 464-466. Ray D, Goswami R, Banerjee U, Dadhwal. V, Goswami D, Mandal P, Sreenivas V,. Kochupillai N. (2007). Prevalence of. Candida glabrata and Its Response to. Boric Acid Vaginal Suppositories in. Comparison With Oral Fluconazole in.

  1. 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

  2. Fluconazole and boric acid for treatment of vaginal candidiasis- New ...

    African Journals Online (AJOL)

    Objective: To compare boric acid as an effective treatment for VVC compared to fluconazole. We also studied the efficiency of these drugs in preventing recurrence of VVC. Design: A cross sectional, randomized, double-blind study. Settings: Gynaecology clinic of Imam Reza hospital, Tehran - Iran. Subjects: Women with ...

  3. Iodine volatility in boric acid/caesium iodide mixtures

    International Nuclear Information System (INIS)

    Deane, A.M.

    1990-07-01

    Measurements of iodide volatility from evaporating boric acid/caesium iodide solutions have not shown measurable iodide volatility but measurements using co-crystallised solid mixtures have shown iodide to be volatile. The volatility of iodide from solid boric acid/caesium iodide has been measured over the temperature range from ambient of 210 0 C using a high surface area mixture. Iodide volatility was detectable at room temperature and appreciable at temperatures above 60 0 C. An Arrhenius relation was not obeyed over the full temperature range. An empirical rate relation was derived, for the conditions of the measurements, to describe the release rate of iodine as HI at temperatures up to the melting point, ca. 169 0 C. At higher temperatures, where the boric acid mixture melted, the rate was lower than would be predicted from that relation, probably because of mass transfer limitation at the melt surface. Because of the dependence of iodide volatility on surface area of the specimen, the relations measured may not apply to another preparation of boric acid/caesium iodide with a different specific surface area. The surface area dependence is a probable explanation of the different observations of iodide volatility from evaporating solutions in different laboratories. (author)

  4. Stress corrosion cracking of steel 316L in concentrated solutions boric acid + chlorides at 100 and 200 deg C: boric acid influence

    International Nuclear Information System (INIS)

    Kasri, R.; Olive, J.M.; Puiggali, M.; Cid, M.; Desjardins, D.

    1993-01-01

    The stainless steel 316L was tested by slow traction in autoclave at 200 deg C. The different stress corrosion sensitive curves (deformation speed for different boric acid contents) may determine the role of boric acid. Stainless steel 316L is submitted to an hyperhardening under inert atmosphere at 1150 deg C during 30 minutes with fast cooling. The solutions contain 2g/l of sodium chloride and variable contents in boric acid. The electrochemical behaviour shows that the obtained currents during the depassivation of the steel and the localized dissolution increase with the boric acid content. 3 refs., 2 figs

  5. 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

  6. 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.

  7. 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)

  8. 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

  9. 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)

  10. 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...

  11. 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 ...

  12. 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-

  13. 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...

  14. 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

  15. The benefits of enriched boric acid in PWRs

    International Nuclear Information System (INIS)

    Wiedenmann, Debra; Nordmann, Francis

    2012-09-01

    The economics of operating pressurized water reactors (PWRs) demand increased fuel economy which in turn places increasing demands on the primary coolant chemistry. Higher energy production can be achieved by using increased enrichment of the nuclear fuel, higher fuel burn up and longer fuel cycles, which in turn requires increased amounts of neutron poison to maintain reactivity control. In addition, greater amounts of chemical shim are required when utilizing alternative, high-reactivity fuels such as mixed uranium/plutonium oxide (MOX) fuels. The B-10 isotope of boron has a high cross section for the absorption of thermal neutrons. However, this isotope comprises only ∼19.6% to 20 % of natural boron. If the boric acid is enriched in the 10 B isotope, then the maximum amount of chemical shim can be increased without exceeding the chemistry limits set by the acidity of boric acid or the concentration limit of lithium (PWR) or potassium (VVER). With sufficient isotopic enrichment, it therefore becomes possible to operate the entire PWR fuel cycle with constant pH 300C at the favored value of 7.2-7.4. The use of Enriched Boric Acid (with ∼40% 10B instead of ∼ 20% in natural boron) consequently provides many advantages in enhancing operational safety and life time of several components, as well as facilitating dose rate reduction programs in PWRs and VVER Nuclear Power Plants. When lowering the total boron concentration in the primary coolant, it is possible to minimize: - dose rates during maintenance activities - optimal pH T from the beginning of the fuel cycle (BOC) can mitigate corrosion products that become activated; - the risk of corrosion of various materials of the Reactor Coolant System - allowing a lower lithium (or potassium) concentration mainly at BOC; the sensitive materials are fuel cladding (zirconium alloy), stainless steels (AISI 304 type), nickel-based Alloy 600; - the risk of Axial Offset Anomalies - resulting from precipitation of boron

  16. Boric acid in germination of pollen grains and fruit set of peach cultivars in subtropical region

    Directory of Open Access Journals (Sweden)

    Filipe Bittencourt Machado de Souza

    Full Text Available ABSTRACT The pollination and fertilization process directly affects the crop yield of peach. Previous studies have shown that some cultivars lack consistent cropping (yield variation in subtropical regions. The application of boric acid at flowering can minimize this problem. This study quantified the germination of pollen grains and fruit set on 18 cultivars of peach in a subtropical region when treated with boric acid at bud. The initial spray treatments were three concentrations of boric acid (400 mgL-1, 800 mgL-1 and 1,200 mgL-1 plus a control treatment of water. Treatments were sprayed on the shoots when the flower buds were flower bud swelling on early maturing cultivars Aurora 2 and Doçura 2. There is a cultivar difference where 'Aurora 2' had a negative effect from the application of boric acid on the percentage of germinated pollen grains and fruit set. 'Doçura 2' has a positive results at the concentration of 400 mgL-1 of boric acid. In a follow-up experiment with 18 cultivars, using only the water control and 400 mgL-1 boric acid treatment, boron increases pollen grain germination and fruit set for some cultivars. The increase in germination and fruit set varies significantly among the cultivars. The concentration of 400 mgL-1 of boric acid increases pollen germination and fruit set, but not in all cultivars.

  17. 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)

  18. 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.

  19. GC/MS Analysis of Bioactive Components of Dracocephalum moldavica L., Treated by Boric Acid Doses

    OpenAIRE

    ARABBAGHI, Ehsan KHADEM; GURBUZ, Bilal; AFSHAR POUR REZAEIEH, Kiarash; UYANIK, Mesut

    2014-01-01

    In this study, carried out to determine effect of boric acid treatments on essential oil compositions in moldavian balm (Dracocephalum moldavica L.), plants were transplanted to experimental area of Department of Field Crops, Faculty of Agriculture of Ankara University with four replicates after rooting. Boric acid concentrations (0, 3, 6 ve 9 kg ha-1 ) were applied as aqueous foliar spray at before flowering stage and plants were harvested at full flowering stage The essential oils were isol...

  20. 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.

  1. 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.

  2. Mechanism of Body Weight Reducing Effect of Oral Boric Acid Intake

    Directory of Open Access Journals (Sweden)

    Erhan Aysan

    2013-01-01

    Full Text Available Objective. The effect of oral boric acid intake on reducing body weight has been previously demonstrated although the mechanism has been unclear. This research study reveals the mechanism. Subjects. Twelve mice were used, in groups of six each in the control and study groups. For five days, control group mice drank standard tap water while during the same time period the study group mice drank tap water which contains 0.28 mg/250 mL boric acid. After a 5-day period, gene expression levels for uncoupling proteins (UCPs in the white adipose tissue (WAT, brown adipose tissue (BAT, and skeletal muscle tissue (SMT and total body weight changes were analyzed. Results. Real time PCR analysis revealed no significant change in UCP3 expressions, but UCP2 in WAT (: 0.0317, BAT (: 0.014, and SMT (: 0.0159 and UCP1 in BAT (: 0.026 were overexpressed in the boric acid group. In addition, mice in the boric acid group lost body weight (mean 28.1% while mice in the control group experienced no weight loss but a slight weight gain (mean 0.09%, . Conclusion. Oral boric acid intake causes overexpression of thermogenic proteins in the adipose and skeletal muscle tissues. Increasing thermogenesis through UCP protein pathway results in the accelerated lipolysis and body weight loss.

  3. Gold Nanoplates for a Localized Surface Plasmon Resonance-Based Boric Acid Sensor

    Directory of Open Access Journals (Sweden)

    Marlia Morsin

    2017-04-01

    Full Text Available Localized surface plasmon resonance (LSPR properties of metallic nanostructures, such as gold, are very sensitive to the dielectric environment of the material, which can simply be adjusted by changing its shape and size through modification of the synthesizing process. Thus, these unique properties are very promising, particularly for the detection of various types of chemicals, for example boric acid which is a non-permitted preservative employed in food preparations. For the sensing material, gold (Au nanoplates with a variety of shapes, i.e., triangular, hexagonal, truncated pentagon and flat rod, were prepared using a seed-mediated growth method. The yield of Au nanoplates was estimated to be ca. 63% over all areas of the sensing material. The nanoplates produced two absorption bands, i.e., the transverse surface plasmon resonance (t-SPR and the longitudinal surface plasmon resonance (l-SPR at 545 nm and 710 nm, respectively. In the sensing study, these two bands were used to examine the response of gold nanoplates to the presence of boric acid in an aqueous environment. In a typical process, when the sample is immersed into an aqueous solution containing boric acid, these two bands may change their intensity and peak centers as a result of the interaction between the boric acid and the gold nanoplates. The changes in the intensities and peak positions of t-SPR and l-SPR linearly correlated with the change in the boric acid concentration in the solution.

  4. Effect of Boric Acid on Volatile Products of Thermooxidative Degradation of Epoxy Polymers

    International Nuclear Information System (INIS)

    Nazarenko, O B; Bukhareva, P B; Melnikova, T V; Visakh, P M

    2016-01-01

    The polymeric materials are characterized by high flammability. The use of flame retardants in order to reduce the flammability of polymers can lead to the formation of toxic gaseous products under fire conditions. In this work we studied the effect of boric acid on the volatile products of thermooxidative degradation of epoxy polymers. The comparative investigations were carried out on the samples of the unfilled epoxy resin and epoxy resin filled with a boric acid at percentage 10 wt. %. The analysis of the volatile decomposition products and thermal stability of the samples under heating in an oxidizing medium was performed using a thermal mass-spectrometric analysis. It is found that the incorporation of boric acid into the polymer matrix increases the thermal stability of epoxy composites and leads to a reduction in the 2-2.7 times of toxic gaseous products (paper)

  5. Effect of Boric Acid on Volatile Products of Thermooxidative Degradation of Epoxy Polymers

    Science.gov (United States)

    Nazarenko, O. B.; Bukhareva, P. B.; Melnikova, T. V.; Visakh, P. M.

    2016-01-01

    The polymeric materials are characterized by high flammability. The use of flame retardants in order to reduce the flammability of polymers can lead to the formation of toxic gaseous products under fire conditions. In this work we studied the effect of boric acid on the volatile products of thermooxidative degradation of epoxy polymers. The comparative investigations were carried out on the samples of the unfilled epoxy resin and epoxy resin filled with a boric acid at percentage 10 wt. %. The analysis of the volatile decomposition products and thermal stability of the samples under heating in an oxidizing medium was performed using a thermal mass-spectrometric analysis. It is found that the incorporation of boric acid into the polymer matrix increases the thermal stability of epoxy composites and leads to a reduction in the 2-2.7 times of toxic gaseous products

  6. 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....

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

    Indian Academy of Sciences (India)

    Multicomponent reaction; amidoalkyl naphthol; boric acid; catalyst; solvent-free synthesis. 1. Introduction. Multicomponent reactions (MCRs), in ... silica-sodium hydrogen sul- phate,14 molybdophosphoric acid (H3[P(Mo3O10)4]),15 ... The solid obtained was collected by filtration and purified by recrystallization from ethanol.

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

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Boric acid has been added in 0⋅1–0⋅6% range for studying the densification characteristics of solid state sintered barium hexaferrite. Sintering studies have been carried out at three different temperatures. Physical properties like density and porosity have been studied for all compositions. The phase identification.

  9. 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.

  10. 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.

  11. The reaction of boric acid with wood in a polystyrene matrix

    Science.gov (United States)

    Yanxin Wang; John Simonsen; Carlos Pascoal Neto; Joao Rocha; Timothy G. Rials; Eric Hart

    1996-01-01

    The reaction of boric acid with wood fibers in a polymer melt was examined using 13C-nuclear magnetic resonance (NMR), 11B-NMR. differential scanning calorimetry, dynamic mechanical analysis, and component extraction and by the determination of material properties. Samples were blended at 350 and 380°F in a roll mill. The...

  12. 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.

  13. 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

  14. 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

  15. 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

  16. STUDY ON SILICIC-BORIC ACID COMBINATION AGAINST WOOD DECAYING FUNGI IN PLYWOOD

    Directory of Open Access Journals (Sweden)

    Shweta BHATT

    2016-09-01

    Full Text Available Plywood as engineered wood product is used for a number of structural and non structural application s for both interior and exterior uses. The exterior exposure creates the conditions for fungi and insects attack, which lead to the early failure of wood products. Preservative treatment is necessary for wood species to improve its resistance against biological agencies. In the present study boric acid, silicic acid and their different combinations i.e. 1:1, 2:1 and 3:1 at 2, 3 and 4% concentrations were tested against wood decaying fungi (Trametes versicolor and Oligoporus placentus in Poplar plywood through soil block test as per IS:4873 (2008. Boric acid has provided the best protection to plywood specimens against the tested fungi. The most effective combination which improved the plywood resistance to fungi was boric acid and silicic acid in 3:1 ratio. While silicic acid was found to be least effective. The efficacy of tested chemicals has improved by using higher concentrations of compounds.

  17. Synthesis and characterization of boric acid mediated metal-organic frameworks based on trimesic acid and terephthalic acid

    Science.gov (United States)

    Ozer, Demet; Köse, Dursun A.; Şahin, Onur; Oztas, Nursen Altuntas

    2017-08-01

    The new metal-organic framework materials based on boric acid reported herein. Sodium and boron containing metal-organic frameworks were synthesized by one-pot self-assembly reaction in the presence of trimesic acid and terephthalic acid in water/ethanol solution. Boric acid is a relatively cheap boron source and boric acid mediated metal-organic framework prepared mild conditions compared to the other boron source based metal-organic framework. The synthesized compounds were characterized by FT-IR, p-XRD, TGA/DTA, elemental analysis, 13C-MAS NMR, 11B-NMR and single crystal measurements. The molecular formulas of compounds were estimated as C18H33B2Na5O28 and C8H24B2Na2O17 according to the structural analysis. The obtained complexes were thermally stable. Surface properties of inorganic polymer complexes were investigated by BET analyses and hydrogen storage properties of compound were also calculated.

  18. 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 ...

  19. 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)

  20. 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.

  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 cut flower longevity (9.69 day) was obtained in pulse-treated flowers with 100 mg l(-1) boric acid. The least ethylene production (0.59 nl(-1) g(-1) h(-1)) was observed in cut 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. 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.

  3. Bubble size distribution in flow boiling of aqueous boric acid under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Nakath, Richard, E-mail: Richard.Nakath@tu-dresden.de; Schuster, Christoph, E-mail: Christoph.Schuster@tu-dresden.de; Hurtado, Antonio, E-mail: Antonio.Hurtado@tu-dresden.de

    2013-09-15

    The focus of this study lies on the effect of boric acid and lithium hydroxide on the bubble size distribution in flow boiling with special regard to pressurized water reactors (PWRs). Previous studies proposed effects similar to those of surface active agents. Transient and stationary measurements of the bubble size distribution with a wire-mesh sensor in a boiling loop with up to 40 bar were taken. The experiments approximated many aspects of reactor conditions. In addition, the physical properties – especially surface tension – at atmospheric pressure of boric acid solutions were determined. The equilibrium surface tension was measured with the Wilhelmy plate method and the dynamic surface tension with the maximum bubble pressure method. Both measurements showed no difference to pure water, which contradicts previously published data. Two types of experiments were performed: transient experiments with the aim to simulate a fast pressure increase in a PWR and stationary experiments simulating normal, i.e. stable, operating conditions. The transient measurements of the bubble-size distribution yielded no detectable difference between deionized water and boric acid solutions. The stationary measurements showed only minor deviations in the range of small gas mass fractions, which decreased with increasing gas mass fraction. The addition of lithium hydroxide seemed to counter this effect.

  4. Survey of boric acid corrosion of carbon steel components in nuclear plants

    International Nuclear Information System (INIS)

    Czajkowski, C.J.

    1990-06-01

    A review has been performed on license responses (50) to Generic Letter 88-05. Joint Brookhaven National Laboratory (BNL) and USNRC audits were performed on a series (10) of affected licensees. The plant audits showed a considerable variance in the mode and quality of boric acid corrosion prevention programs between utilities. The degree of importance of a boric acid corrosion control program also varied considerably between plants. In the plants where a reasonably high priority was given to the problem, the leaks were identified and corrective actions taken in a timely manner. Each of the plants audited had a boric acid corrosion prevention program in effect at the time of the plant visit. In many cases, the program consisted of modifications to existing leakage control procedures. Training of inspectors was accomplished by all audited licensees. In general, the inspectors were certified to the VT-2 qualification and in some instances to the EPRI visual inspection certifications. In general, all of the sites audited kept their plants relatively clean (with one exception). The majority of plants either cleaned their spills in short order and repaired the leaks or found methods of draining or containment of the liquids. All of the audited licensees satisfactorily addressed the four specified requirements of Generic Letter 88-05. 22 refs., 3 figs., 2 tabs

  5. 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.

  6. An improved solvent-free synthesis of flunixin and 2-(arylamino) nicotinic acid derivatives using boric acid as catalyst.

    Science.gov (United States)

    Yarhosseini, Mahsa; Javanshir, Shahrzad; Dolatkhah, Zahra; Dekamin, Mohammad G

    2017-12-01

    A simple solvent-free protocol for the preparation of flunixin, a potent non-narcotic, non-steroidal anti-inflammatory drugs is reported using boric acid as catalyst. Its salt, flunixin meglumine are then prepared under reflux in EtOH. This sustainable method are then extended for the synthesis of a series of 2-(arylamino) nicotinic acid derivatives. The present protocol combines non-hazardous neat conditions with associated benefits like excellent yield, straightforward workup, and use of readily available and safe catalyst in the absence of any solvent, which are important factors in the pharmaceutical industry. The pathway for catalytic activation of 2-chloronicotic acid with boric acid was also investigated using Gaussian 03 program package.

  7. 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.

  8. The kinetic deuterium isotope effect in the thermal dehydration of boric acid

    International Nuclear Information System (INIS)

    Tanaka, H.; Ohshima, S.; Ichiba, S.; Negita, H.

    1981-01-01

    The kinetic deuterium isotope effect in the thermal dehydration process from H 3 BO 3 to HBO 2 (III) was determined using simultaneous TG and DSC. The rate constant ratio of H 3 BO 3 to D 3 BO 3 obtained by the analysis of isothermal TG and DSC curves was found to be smaller than unity. Both activation energy, E, and frequency factor, A, for the dehydration of H 3 BO 3 proved to be larger than those of D 3 BO 3 , using non-isothermal TG and DSC. The origin of the deuterium kinetic isotope effect in the thermal dehydration of boric acid is also briefly discussed. (orig.)

  9. 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.)

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Hydrolysis and transesterification of parabens in an aqueous solution in the presence of glycerol and boric acid

    OpenAIRE

    Oldrich Farsa; Jan Subert; Marie Marečkova

    2011-01-01

    In a solution containing 0.067% methylparaben, 0.033% propylparaben, 3.4% glycerol and 2.0% boric acid, concentrations of both parabens, 4 hydroxybenzoic acid and 2,3-dihydroxypropyl 4-hydroxybenzoate were monitored for up to 68 months storage. 4-hydroxybenzoic acid is the main hydrolysis product of parabens, while 2,3-dihydroxypropyl 4 hydroxybenzoate was proposed as the main product of transesterification of parabens with glycerol. Results of an HPLC evaluation of parabens, 4-hydroxybenzoic...

  16. Synthesis of boron carbide nano particles using polyvinyl alcohol and boric acid

    Directory of Open Access Journals (Sweden)

    Amir Fathi

    2012-03-01

    Full Text Available In this study boron carbide nano particles were synthesized using polyvinyl alcohol and boric acid. First, initial samples with molar ratio of PVA : H3BO3 = 2.7:2.2 were prepared. Next, samples were pyrolyzed at 600, 700 and 800°C followed by heat treatment at 1400, 1500 and 1600°C. FTIR analysis was implemented before and after pyrolysis in order to study the reaction pathway. XRD technique was used to study the composition of produced specimens of boron carbide. Moreover, SEM and PSA analysis were also carried out to study the particle size and morphology of synthesized boron carbide. Finally, according to implemented tests and analyses, carbon-free boron carbide nano particles with an average size of 81 nm and mainly spherical morphology were successfully produced via this method.

  17. 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.

  18. Column chromatographic boron isotope separation at 5 and 17 MPa with diluted boric acid solution.

    Science.gov (United States)

    Musashi, Masaaki; Oi, Takao; Matsuo, Motoyuki; Nomura, Masao

    2008-08-01

    Boron isotopic fractionation factor (S) between boron taken up in strongly basic anion exchange resin and boron in aqueous solution was determined by breakthrough column chromatography at 5 and 17 MPa at 25 degrees C, using 0.1 mM boric acid solution as feed solution. The S values obtained were 1.018 and 1.012, respectively, which were smaller than the value reported by using the same chromatographic method at the atmospheric pressure at 25 degrees C with the boron concentration of 10mM, but were larger than the values under the same condition with much higher concentration of 100 and 501 mM. Calculations based on the theory of isotope distribution between two phases estimated that 21% (5 MPa) and 47% (17 MPa) of boron taken up in the resin phase was in the three-coordinated B(OH)(3)-form, instead of in the four-coordinated B(OH)(4)-form, at high pressures even with a very diluted boric acid solution. We discussed the present results by introducing (1) hydration and (2) a partial molar volume difference between isotopic molecules. Borate may have been partially dehydrated upon transfer from the solution phase to the resin phase at high pressures, which resulted in smaller S values compared with those at the atmospheric pressure. Instead, it may be possible that the difference in the isotopic partial molar volume difference between B(OH)(3) and B(OH)(4)(-) caused the S value to decrease with increasing pressure.

  19. 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)

  20. 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)

  1. 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

  2. Alternative method for thermal neutron flux measurements based on common boric acid as converter and Lr-15 detectors

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, D.; Greaves, E. D.; Sajo B, L.; Barros, H. [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apdo. Postal 89000, Caracas (Venezuela, Bolivarian Republic of); Ingles, R. [Universidad Nacional de San Antonio Abad del Cusco, Av. de la Cultura No. 733, Cusco (Peru)

    2010-02-15

    A method to determine the flux and angular distribution of thermal neutrons with the use of Lr-115 detectors was developed. The use of the Lr-115 detector involves the exposure of a pressed boric acid sample (tablet) as a target, in tight contact with the track detector, to a flux of thermalized neutrons. The self-absorption effects in thin films or foil type thermal neutron detectors can be neglected by using the Lr-115 detector and boric acid tablet setup to operate via backside irradiation. The energy window and the critical angle-residual energy curve were determined by comparisons between the experimental and simulated track parameters. A computer program was developed to calculate the detector registration efficiency, so that the thermal neutron flux can be calculated from the track densities induced in the Lr-115 detector using the derived empirical formula. The proposed setup can serves as directional detector of thermal neutrons. (Author)

  3. Synthesis and evaluation of aminoborates derived from boric acid and diols for protecting wood against fungal and thermal degradation

    Science.gov (United States)

    George C. Chen

    2008-01-01

    N-methyl amino catechol borate (1), N-methyl amino-4-methyl catechol borate (2), N-methyl amino-4-t-butyl catechol borate (3), and N-methyl amino-2, 3-naphthyl borate (4) were synthesized by reflux of boric acid with a diol in solvent N,N-dimethyl formamide. The aminoborates were characterized by proton nuclear magnetic resonance spectroscopy, FTIR spectroscopy and...

  4. 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...

  5. 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 ...

  6. Electrical conductivity measurements of aqueous boric acid at 25--350{degree}C at saturation vapor pressure. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ho, P.C.; Palmer, D.A.

    1995-09-01

    Electrical conductance measurements of aqueous boric acid solutions (15-110 g/kg-H{sub 2}O {equivalent_to} 0.251--1.815 mol/kg-H{sub 2}O) were measured over the temperature range 25 to 75 C at saturation vapor pressures in glass cells with parallel platinum electrodes. Sixteen series of measurements were made involving three samples of boric acid from different sources. Conductance measurements were also made at 15.5 and 30.5 g/kg-H{sub 2}O over the temperature range 100 to 350 C at 50 C intervals with a metallic cell fitted with concentric platinum electrodes. The specific conductances of H{sub 3}BO{sub 3} (aq)were calculated after correction for the conductance of the solvent (water) and are tabulated in this report. At the specific conditions requested in the project description, namely a concentration of 110 g/kg-H{sub 2}O and 65 C, the specific conductance of boric acid is 293.2 {+-} 1.8 microSiemens/cm based on duplicate measurements of four independent solutions. The results from these tests will be utilized by the Tokamak Physics Experimental Project (TPX).

  7. 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.

  8. Potential of using boric acid as a boron drug for boron neutron capture therapy for osteosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, C.F.; Lin, S.Y. [Institute of Nuclear Engineering and Science, National Tsing Hua University, Taiwan (China); Peir, J.J. [Nuclear Science and Technology Development Center, National Tsing Hua University, Taiwan (China); Liao, J.W. [Graduate Institute of Veterinary Pathobiology, National Chung Hsing University, Taiwan (China); Lin, Y.C. [Department of Veterinary Medicine, National Chung Hsing University, Taiwan (China); Chou, F.I., E-mail: fichou@mx.nthu.edu.tw [Institute of Nuclear Engineering and Science, National Tsing Hua University, Taiwan (China)] [Nuclear Science and Technology Development Center, National Tsing Hua University, Taiwan (China)

    2011-12-15

    Osteosarcoma is a malignant tumor commonly found in human and animals. The ability of boric acid (BA) to accumulate in osteosarcoma due to the mechanism of the bone formation of cancer cells would make boron neutron capture therapy (BNCT) an alternative therapy for osteosarcoma. This study evaluated the feasibility of using BA as the boron drug for BNCT of bone cancer. The cytotoxicity of BA to L929 cells exceeded that of UMR-106 cells. With 25 {mu}g {sup 10}B/mL medium of BA treatment, the boron concentration in UMR-106 cells was higher than that in L929 cells. The biodistribution and pharmacokinetics of BA in Sprague-Dawley (SD) rats were studied by administrating 25 mg {sup 10}B/kg body weight to SD rats. Blood boron level decreased rapidly within one hour after BA injection. Boron concentration in the long bone was 4-6 time higher than that of blood. Results of this study suggest that BA may be a potential drug for BNCT for osteosarcoma.

  9. The neuroprotective role of boric acid on aluminum chloride-induced neurotoxicity.

    Science.gov (United States)

    Colak, Suat; Geyikoglu, Fatime; Keles, Osman Nuri; Türkez, Hasan; Topal, Ahmet; Unal, Bünyami

    2011-09-01

    This study was designed to investigate the qualitative and quantitative changes in brain tissue following aluminum chloride (AlCl(3)) administration and to determine whether boric acid (BA) has a protective effect against brain damage induced by AlCl( 3). For this aim, Sprague-Dawley rats were randomly separated into eight groups: (1) control, (2) AlCl(3) (5 mg/kg/day), (3, 4 and 5) BA (3.25, 36 and 58.5 mg/kg/day), (6, 7 and 8) AlCl(3) (5 mg/kg/day) plus BA (3.25, 36 and 58.5 mg/kg/day). After the animals were killed, the total numbers of neuron in the brain of all groups were determined using an unbiased stereological analysis. In addition to the stereological analysis, all brains were examined histopathologically by using light and electron microscopy. The stereological and histopathological results indicated a high damage of the rat brain tissues in the AlCl(3) and AlCl(3) + high dose BA (36 and 58.5) treatment groups. However, protective effects on neuron were observed in the AlCl(3) + low dose BA (3.25) group when compared other AlCl(3) groups. Our stereological and histopathological findings show that low-dose BA, as a proteasome inhibitor, can decrease the adverse effects of AlCl(3) on the cerebral cortex.

  10. Mechanism simulation of H2O2 formation by γ-rays irradiation in boric acid solution

    International Nuclear Information System (INIS)

    Sunaryo, Geni Rina; Sumijanto; Arifal; Latifah, Siti Nurul; Santoso, Urip

    1998-01-01

    The mechanism reaction analysis of boric aid solutions up to temperature of 150 o C was done to understand the reaction mechanism, so the further action for reducing the diluted oxygen in cooling system can be determined. The analysis was done by using fitting method between experimental and simulation results by F acsimile s oftware. The inputs data is one of the probable scheme reactions in aeration boric acid which is irradiated by using γ-rays including the rate constants, G-value, doses and the temperature dependence systems concentration. The unknown rate constant at high temperature is calculated by using the activation energy of 3 kcal. From the fitting simulation, it is known that the presence of proton and oxygen in the solution will in crease the oxidizer of H 2 O 2 production 10 times, but higher oxygen concentration of 1μM will not give the significant effect anymore. The most reactive species for oxygen degradation is H radical at 25 o C. The fraction reaction of H atom and oxygen increase 10 times higher at 150 o C. The degradation reaction of oxygen by hydrated electron at 150 o C become significant. From the fitting simulation, it is known that the reaction between boric acid and hydrogen peroxide degradation species such OH and H was assumed to be occurred with the rate constants of 6 magnitude

  11. 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.

  12. 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.

  13. Hydrolysis and transesterification of parabens in an aqueous solution in the presence of glycerol and boric acid

    Directory of Open Access Journals (Sweden)

    Oldrich Farsa

    2011-06-01

    Full Text Available In a solution containing 0.067% methylparaben, 0.033% propylparaben, 3.4% glycerol and 2.0% boric acid, concentrations of both parabens, 4 hydroxybenzoic acid and 2,3-dihydroxypropyl 4-hydroxybenzoate were monitored for up to 68 months storage. 4-hydroxybenzoic acid is the main hydrolysis product of parabens, while 2,3-dihydroxypropyl 4 hydroxybenzoate was proposed as the main product of transesterification of parabens with glycerol. Results of an HPLC evaluation of parabens, 4-hydroxybenzoic acid and 2,3- dihydroxypropyl 4-hydroxybenzoate showed that the decomposition of 68 months old samples stored at room temperature did not exceed 2.0%. The stability of both parabens in a medicinal preparation of the stated composition has thus been satisfactorily demonstrated after more than 5 years of storage under ambient conditions. The transesterification reaction was shown to influence the chemical stability of parabens to an extent comparable to hydrolysis. Moreover, the presence of 2,3-dihydroxypropyl 4-hydroxybenzoate in the solution containing glycerol and boric acid was confirmed by 1H-NMR spectroscopy.

  14. Determination of Li generated from 10B(n·α)7Li reaction in Boric acid solution

    International Nuclear Information System (INIS)

    Choi, Ke-Chon; Jung, Yong-Ju; Yeon, Jei-Won; Kim, Won-Ho

    2003-01-01

    Thermal neutron irradiation experiment of boric acid solution was carried out using HANARO in following three conditions: 10 B concentration = 203.0 μg/mL, irradiation time = 1 hr; 10 B concentration = 381.4 μg/mL, irradiation time = 1 hr; 10 B concentration = 381.4 μg/mL, irradiation time = 0.5 hr. The amount of lithium produced from 10 B(n·α) 7 Li reaction which was generated on neutron irradiation, was measured by flameless atomic absorption spectroscopy. The concentration of 7 Li measured in the three experiments was 0.18 μg/mL (78.3% of theoretical value, 0.23 μg/mL) in 10 B concentration = 203.0 μg/mL irradiation time = 1 hr, 0.31 μg/mL (7.05% of theoretical value, 0.44 μg/mL) in 10 B concentration = 381.4 μg/mL, irradiation time = 1 hr and 0.16 μg/mL (73.6% of theoretical value, 0.22 μg/mL) in 10 B concentration = 381.4 μg/mL, irradiation time = 0.5 hr. The pH value of irradiated boric acid was shifted to considerably low. It is estimated that boric acid would be transformed into the polyborate form, by radiolysis products of water, which has high dissociation constant

  15. 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.

  16. Voltammetric study of the boric acid-salicylaldehyde-H-acid ternary system and its application to the voltammetric determination of boron.

    Science.gov (United States)

    Kajiwara, Mari; Ito, Yoshio N; Miyazaki, Yoshinobu; Fujimori, Takao; Takehara, Kô; Yoshimura, Kazuhisa

    2015-02-14

    The ternary system of boric acid, salicylaldehyde (SA) and H-acid (HA) was voltammetrically studied from kinetic and equilibrium points of view. The effect of the SA substituents was also studied by using two analogs, 5-fluorosalicylaldehyde (F-SA) and 5-methylsalicylaldehyde (Me-SA). The three cathodic peaks of Azomethine H (AzH), Azomethine H-boric acid complex (AzB), and free SA were observed in the solution containing boric acid, SA and HA. The peak potentials of AzH and SA were shifted to negative potentials with increasing pH, while the peak potential of AzB was pH-independent. This difference indicates that a proton participates in the charge-transfer steps of the AzH and SA reductions, but not in that of the AzB reduction. The formation constants for the AzB complexation were similar among all the examined analogs. In the kinetic study, the reaction rate was higher in an acidic condition for the AzH formation, but in a neutral condition for the AzB formation. The rate constants for the AzB complexes were in the order of F-SA > SA ≈ Me-SA, indicating that the fluoro group accelerates the F-AzB complexation. The AzB complexation mechanism is considered to consist of more than three steps, i.e., the pre-equilibrium of the salicylaldehyde-boric acid complex (SA-B) formation, the nucleophilic attack of HA on SA-B, and the remaining some steps to form AzB. Based on these results, the voltammetric determination method of boron using F-SA was optimized, which allowed the boron concentration to be determined within only 5 min with a 0.03 mg B dm(-3) detection limit.

  17. 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...

  18. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Science.gov (United States)

    2010-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

  19. 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

  20. 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...

  1. 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.

  2. 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.

  3. 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)

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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)

  9. 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

  10. Assessment of the chemical changes induced in human melanoma cells by boric acid treatment using infrared imaging.

    Science.gov (United States)

    Acerbo, Alvin S; Miller, Lisa M

    2009-08-01

    Boron is found in everyday foods and drinking water in trace quantities. Boron exists as boric acid (BA) within plants and animals, where low levels have been linked to cancer incidence. However, this correlation is not well characterized. In this study, we examined the chemical and morphological effects of BA on human skin melanoma cells (SK-MEL28) using Fourier Transform InfraRed Imaging (FTIRI) with a Focal Plane Array (FPA) detector. Cells were grown under concentrations of BA ranging from 0 to 50 mM. Cell viability was determined after 1, 2, 3, 5, 7 and 10 days using trypan blue staining. With FTIRI, images of approximately twenty cells per time point per condition were collected. Principal components analysis (PCA) was used to evaluate changes in cell composition, with particular focus on the lipid, protein, and nucleic acid spectral components. Results from trypan blue staining revealed decreased cell viability as BA concentration increased. FTIRI data indicated that the protein and lipid contents (as indicated by the lipid/protein ratio) did not undergo substantial changes due to BA treatment. In contrast, the nucleic acid/protein ratio significantly decreased with BA treatment. PCA results showed an increase in beta-sheet protein at higher concentrations of BA (12.5, 25, and 50 mM). Together, these results suggest that high concentrations of BA have an anti-proliferative effect and show signs consistent with apoptosis.

  11. Synthesis and evaluation of borates derived from boric acid and diols for the protection of wood against fungal decay and thermal degradation

    Science.gov (United States)

    George C. Chen

    2004-01-01

    N,N-dimethyl amino carbinol catechol borate(1). N,N-dimethyl amino carbinol-4-methyl catechol borate(2), N,N-dimethyl amino carbinol-4-t- butyl catechol borate(3). N,N-dimethyl amino carbinol-2,3-naphthyl borate 4) were synthesized by refluxing boric acid and diol in DMF(N,N-dimethyl formamide). The borates were characterized by NMR. Wood impregnated with borate 1,2 or...

  12. Controlling the optical properties of polyaniline doped by boric acid particles by changing their doping agent and initiator concentration

    Science.gov (United States)

    Cabuk, Mehmet; Gündüz, Bayram

    2017-12-01

    In this study, polyaniline doped by boric acid (PAni:BA) conducting polymers were chemically synthesized by oxidative polymerization method using (NH4)2S208 (APS) as initiator. Pani:BA conducting polymers were synthesized by using two different APS/aniline molar ratios as 1:1 and 2:1. Their results were compared with PAni doped by HCl (PAni) conducting polymer. Structural properties of the PAni, PAni:BA (1:1) and PAni:BA (2:1) conducting polymers were characterized by using FTIR, SEM, TGA, particle size and apparent density measurements. Effects of doping agents and initiator concentrations on optical properties were investigated in detail. The optoelectronic parameters such as absorption band edge, molar extinction coefficient, direct allowed band gap, refractive index, optical conductance and electrical conductance of the PAni, PAni:BA (1:1) and PAni:BA (2:1) were determined. The absorption band edge and direct allowed band gap of PAni were decreased with doping BA and increasing APS ratio. Also, the refractive index values of the materials were calculated from experimental results and compared with obtained results from Moss, Ravindra, Herve-Vandamme, Reddy and Kumar-Singh relations.

  13. 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.

  14. OsNIP3;1, a rice boric acid channel, regulates boron distribution and is essential for growth under boron-deficient conditions.

    Science.gov (United States)

    Hanaoka, Hideki; Uraguchi, Shimpei; Takano, Junpei; Tanaka, Mayuki; Fujiwara, Toru

    2014-06-01

    Boron is an essential micronutrient for higher plants. Boron deficiency is an important agricultural issue because it results in loss of yield quality and/or quantity in cereals and other crops. To understand boron transport mechanisms in cereals, we characterized OsNIP3;1, a member of the major intrinsic protein family in rice (Oryza sativa L.), because OsNIP3;1 is the most similar rice gene to the Arabidopsis thaliana boric acid channel genes AtNIP5;1 and AtNIP6;1. Yeast cells expressing OsNIP3;1 imported more boric acid than control cells. GFP-tagged OsNIP3;1 expressed in tobacco BY2 cells was localized to the plasma membrane. The accumulation of OsNIP3;1 transcript increased fivefold in roots within 6 h of the onset of boron starvation, but not in shoots. Promoter-GUS analysis suggested that OsNIP3;1 is expressed mainly in exodermal cells and steles in roots, as well as in cells around the vascular bundles in leaf sheaths and pericycle cells around the xylem in leaf blades. The growth of OsNIP3;1 RNAi plants was impaired under boron limitation. These results indicate that OsNIP3;1 functions as a boric acid channel, and is required for acclimation to boron limitation. Boron distribution among shoot tissues was altered in OsNIP3;1 knockdown plants, especially under boron-deficient conditions. This result demonstrates that OsNIP3;1 regulates boron distribution among shoot tissues, and that the correct boron distribution is crucial for plant growth. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  15. 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

  16. Determination of crude protein in animal feed, forage, grain, and oilseeds by using block digestion with a copper catalyst and steam distillation into boric acid: collaborative study.

    Science.gov (United States)

    Thiex, Nancy J; Manson, Harold; Andersson, Shirley; Persson, Jan-Ake

    2002-01-01

    A collaborative study was conducted to evaluate the repeatability and reproducibility of an extension of AOAC Official Method 991.20, Nitrogen (Crude) in Milk, to animal feed, forage (plant tissue), grain, and oilseed materials. Test portions are digested in an aluminum block at 420 degrees C in sulfuric acid with potassium sulfate and a copper catalyst. Digests are cooled and diluted, and concentrated sodium hydroxide is added to neutralize the acid and make the digest basic; the liberated ammonia is distilled by using steam distillation. The liberated ammonia is trapped in a weak boric acid solution and titrated with a stronger standardized acid, hydrochloric acid; colorimetric endpoint detection is used. Fourteen blind samples were sent to 13 collaborators in the United States, Denmark, Sweden, Germany, and the United Kingdom. Recoveries of nitrogen from lysine, tryptophan, and acetanilide were 86.8, 98.8, and 100.1%, respectively. The within-laboratory relative standard deviation (RSDr, repeatability) ranged from 0.40 to 2.38% for crude protein. The among-laboratories (including within-) relative standard deviation (RSD(R), reproducibility) ranged from 0.44 to 2.38%. It is recommended that the method be adopted First Action by AOAC INTERNATIONAL. A lower concentration (1% H3BO3) of trapping solution was compared with the concentration specified in the original protocol (4% H3BO3) and was found comparable for use in an automatic titration system in which titration begins automatically as soon as distillation starts. The Study Directors recommend that 1% H3BO3 as an optional alternative to 4% boric acid trapping solution be allowed for automatic titrators that titrate throughout the distillation.

  17. Effect of single flame retardant aluminum tri-hydroxide and boric acid against inflammability and biodegradability of recycled PP/KF composites

    Science.gov (United States)

    Suharty, Neng Sri; Dihardjo, Kuncoro; Handayani, Desi Suci; Firdaus, Maulidan

    2016-03-01

    Composites rPP/DVB/AA/KF had been reactively synthesized in melt using starting material: recycled polypropylene (rPP), kenaf fiber (KF), multifunctional compound acrylic acid (AA), compatibilizer divinyl benzene (DVB). To improve the inflammability of composites, single flame retardant aluminum tri-hydroxide (ATH) and boric acid (BA) as an additive was added. The inflammability of the composites was tested according to ASTM D635. By using 20% ATH and 5% BA additive in the composites it is effectively inhibiting its time to ignition (TTI). Its burning rate (BR) can be reduced and its heat realease (%HR) decreases. The biodegradability of composites was quantified by its losing weight (LW) of composites after buried for 4 months in the media with rich cellulolytic bacteria. The result shows that the LW of composites in the presence 20% ATH and 5% BA is 6.3%.

  18. Silica-supported boric acid with ionic liquid: a novel recyclable catalytic system for one-pot three-component Mannich reaction.

    Science.gov (United States)

    Kumar, Vishal; Sharma, Upendra; Verma, Praveen Kumar; Kumar, Neeraj; Singh, Bikram

    2011-01-01

    A rapid and efficient silica-supported boric acid/ionic liquid ([bmim][PF₆]), catalyzed, one-pot three-component Mannich reaction has been carried out to synthesize β-amino carbonyl compounds at room temperature. The reaction afforded desired products in excellent yields with moderate to good diastereoselectivity. The method provides a novel modification of three-component Mannich reaction in terms of mild reaction conditions, clean reaction profiles, low amount of catalyst, recyclability of catalyst and a simple workup procedure. The present report first time describes the preparation of H₃BO₃-SiO₃ catalyst and its use with [bmim][PF₆], to synthesize Mannich products. The catalyst can be reused at least seven times.

  19. A study on chemical separation of {sup 55}Fe, {sup 59}Ni, {sup 63}Ni, {sup 90}Sr and {sup 94}Nb in boric acid matrix

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C. H.; Kim, W. H.; Jee, K. Y. [KAERI, Taejon (Korea, Republic of); Jung, K. C. [Atomie Creative Technology, Taejon (Korea, Republic of); Im, S. N. [Korea Hydraulic and Nuclear Power Company, Taejon (Korea, Republic of)

    2004-07-01

    Several radionuclides are considered as an object of the assesment to develop a scaling factor and a periodical verification method which are needed for the evaluation of radionuclide inventory of concentration bottoms from nuclear power plants in Korea. A selective separation of {sup 55}Fe, {sup 59}Ni, {sup 63}Ni, {sup 90}Sr and {sup 94}Nb which should be recovered individually for the radioactivity measurement was described in detail. Sorption and desorption behaviours of ion exchange and extraction chromatographic resins for Fe, Ni, Sr, Nb and co-existing metal ions in boric acid matrix were investigated using simulated concentration bottom dissolved solutions. Separation conditions available for the sequential recovery of the metal ions from a single sample were optimized to minimize a discharge of radioactive wastes produced through the analytical process and the radiation exposure to analysts. Their recovery yields were measured with reliability.

  20. 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.

  1. 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

  2. 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.

  3. Polar Localization of the NIP5;1 Boric Acid Channel Is Maintained by Endocytosis and Facilitates Boron Transport in Arabidopsis Roots.

    Science.gov (United States)

    Wang, Sheliang; Yoshinari, Akira; Shimada, Tomoo; Hara-Nishimura, Ikuko; Mitani-Ueno, Namiki; Feng Ma, Jian; Naito, Satoshi; Takano, Junpei

    2017-04-01

    Boron uptake in Arabidopsis thaliana is mediated by nodulin 26-like intrinsic protein 5;1 (NIP5;1), a boric acid channel that is located preferentially on the soil side of the plasma membrane in root cells. However, the mechanism underlying this polar localization is poorly understood. Here, we show that the polar localization of NIP5;1 in epidermal and endodermal root cells is mediated by the phosphorylation of Thr residues in the conserved TPG (ThrProGly) repeat in the N-terminal region of NIP5;1. Although substitutions of Ala for three Thr residues in the TPG repeat did not affect lateral diffusion in the plasma membrane, these substitutions inhibited endocytosis and strongly compromised the polar localization of GFP-NIP5;1. Consistent with this, the polar localization was compromised in µ subunit mutants of the clathrin adaptor AP2. The Thr-to-Ala substitutions did not affect the boron transport activity of GFP-NIP5;1 in Xenopus laevis oocytes but did inhibit the ability to complement boron translocation to shoots and rescue growth defects in nip5;1-1 mutant plants under boron-limited conditions. These results demonstrate that the polar localization of NIP5;1 is maintained by clathrin-mediated endocytosis, is dependent on phosphorylation in the TPG repeat, and is necessary for the efficient transport of boron in roots. © 2017 American Society of Plant Biologists. All rights reserved.

  4. Efficient boron abstraction using honeycomb-like porous magnetic hybrids: Assessment of techno-economic recovery of boric acid.

    Science.gov (United States)

    Oladipo, Akeem Adeyemi; Gazi, Mustafa

    2016-12-01

    Porous magnetic hybrids were synthesized and functionalized with glycidol to produce boron-selective adsorbent. The magnetic hybrid (MH) comparatively out-performed the existing expensive adsorbents. MH had a saturation magnetisation of 63.48 emu/g and average pore diameter ranging from meso to macropores. The magnetic hybrids showed excellent selectivity towards boron and resulted in 79-93% boron removal even in the presence of competing metal ions (Na + and Cr 2+ ). Experiments were performed in a column system, and breakthrough time was observed to increase with bed depths and decreased with flow rates. The batch experiments revealed that 60 min was enough to achieve equilibrium, and the level of boron sorption was 108.5 mg/g from a synthetic solution. Several adsorption-desorption cycles were performed using a simple acid-water treatment and evaluated using various kinetic models. The spent adsorbents could be separated easily from the mixture by an external magnetic field. The cost-benefit analysis was performed for the treatment of 72 m 3 /year boron effluent, including five years straight line depreciation charges of equipment. The net profit and standard percentage confirmed that the recovery process is economically feasible. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. 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.

  6. Retention of ionisable compounds on high-performance liquid chromatography XVIII: pH variation in mobile phases containing formic acid, piperazine, tris, boric acid or carbonate as buffering systems and acetonitrile as organic modifier.

    Science.gov (United States)

    Subirats, Xavier; Bosch, Elisabeth; Rosés, Martí

    2009-03-20

    In the present work dissociation constants of commonly used buffering species, formic acid, piperazine, tris(hydroxymethyl)-aminomethane, boric acid and carbonate, have been determined for several acetonitrile-water mixtures. From these pK(a) values a previous model has been successfully evaluated to estimate pH values in acetonitrile-aqueous buffer mobile phases from the aqueous pH and concentration of the above mentioned buffers up to 60% of acetonitrile, and aqueous buffer concentrations between 0.005 (0.001 mol L(-1) for formic acid-formate) and 0.1 mol L(-1). The relationships derived for the presently studied buffers, together with those established for previously considered buffering systems, allow a general prediction of the pH variation of the most commonly used HPLC buffers when the composition of the acetonitrile-water mobile phase changes during the chromatographic process, such as in gradient elution. Thus, they are an interesting tool that can be easily implemented in general retention models to predict retention of acid-base analytes and optimize chromatographic separations.

  7. 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.)

  8. 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

  9. 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)

  10. 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

  11. 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

  12. 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

  13. Boric Ester-Type Molten Salt via Dehydrocoupling Reaction

    OpenAIRE

    Noriyoshi Matsumi; Yoshiyuki Toyota; Prerna Joshi; Puhup Puneet; Raman Vedarajan; Toshihiro Takekawa

    2014-01-01

    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 molt...

  14. Boric ester-type molten salt via dehydrocoupling reaction.

    Science.gov (United States)

    Matsumi, Noriyoshi; Toyota, Yoshiyuki; Joshi, Prerna; Puneet, Puhup; Vedarajan, Raman; Takekawa, Toshihiro

    2014-11-14

    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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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)

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

    African Journals Online (AJOL)

    The samples were cultured in Sabouraud's dextrose agar (supplemented with 0.005% chloramphenicol and 0.05% cycloheximide) followed by aerobic incubation for 48 hours at 37ºC in order to obtain pure cultures. Identification was done by Gram stain, while the test for ability to ferment and assimilate different sugars was ...

  1. 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)

  2. 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.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2009-02-18

    Feb 18, 2009 ... mance and its economic and medical importance. (Gordon, 1996; Grandcolas, 1998). Thus, many conventional pesticides have been replaced by newer biorational or low risk insecticides with novel mode of action like insect growth regulators and biopesticides (Horowitz and Ishaaya, 2002; Dhadialla et.

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

    African Journals Online (AJOL)

    ufuoma

    2013-05-01

    May 1, 2013 ... Laboratory of Applied Animal Biology, Department of Biology, Faculty of Science, University of BADJ Mokhtar Annaba,. 23000, Annaba, Algeria. Accepted 18 April, 2013. Pestiferous cockroach ... made by oral administration) by our team (Habes et al.,. 2006), its effect was tested by injection, assessing the.

  5. 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

  6. Performance Characteristics of Borate Fatty Acid Formulations as Mold Inhibitors

    Science.gov (United States)

    Robert D. Coleman; Vina Yang; Carol A. Clausen

    2013-01-01

    The combination of boric acid (BA) or disodium octaborate tetrahydrate (DOT) and a fatty acid (FA) such as heptanoic, octanoic, and nonanoic acids (C7–C9) is an effective treatment solution for protecting wood structures against mold. BA or DOT alone have substantial potency against insects and decay fungi, but have negligible or no mold inhibitor activity. However,...

  7. 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

  8. 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 ...

  9. Synthesis of Nanocrystalline Boron Carbide by Direct Microwave Carbothermal Reduction of Boric Acid

    Directory of Open Access Journals (Sweden)

    Rodolfo F. K. Gunnewiek

    2017-01-01

    Full Text Available The excellent physical and chemical properties of boron carbide make it suitable for many applications. However, its synthesis requires a large amount of energy and is time-consuming. Microwave carbothermal reduction is a fast technique for producing well crystallized equiaxial boron carbide nanoparticles of about 50 nm and very few amounts of elongated nanoparticles were also synthesized. They presented an average length of 82 nm and a high aspect ratio (5.5. The total reaction time was only 20 minutes, which disfavor the growing process, leading to the synthesis of nanoparticles. Microwave-assisted synthesis leaded to producing boron-rich boron carbide. Increasing the forward power increases the boron content and enhances the efficiency of the reaction, resulting in better crystallized boron carbide.

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

    Indian Academy of Sciences (India)

    Unknown

    (b) Formation constants of FeIII – H3BO3 complexes. (i) Overall formation constants. Fe. ) BO. Fe(H. 4. 2 logβ. 3⋅67. Fe. ) BO. Fe(OH)(H. 4. 2 logβ. 1⋅16. Fe. ) BO. (H. Fe(OH). 4. 2. 2 logβ. –1⋅72. (ii) Effect of coordination with Fe(aq)3+, Fe(OH)2+ and Fe(OH). +. 2 on ionisation of. H3BO3. 3H. O]. H. BO. H. [Fe. 2. 3. 3 log. +. +.

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

    Indian Academy of Sciences (India)

    Unknown

    bipyridine and 1,10-phenanthroline. Complex formation equilibria and stability constants of the complexes at 25 ± 0⋅1°C in aqueous solution at a fixed ionic strength,. I = 0⋅1 mol dm–3 (NaNO3) have been determined by potentiometric method.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-18

    Aug 18, 2009 ... weights of the growing rings may also result in color dis- tinction. By the chemical degradation of extractive mate- ... dipping method (Atar et al., 2007). It was assessed that the impregnation of hardwoods ... sed a decrease of 8 - 12% in the red color tone of dif- ferent wood types (Ors et al., 2005). Scotch pine ...

  13. 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)

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

    Indian Academy of Sciences (India)

    Sintering studies have been carried out at three different temperatures. 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 ...

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

    Indian Academy of Sciences (India)

    borate complexes; CrIII-borate complexes in solution. ... Author Affiliations. G N Mukherjee1 Ansuman Das1. Department of Chemistry, University of Calcutta, University College of Science, 92, Acharya Prafulla Chandra Road, Kolkata 700 009, India ...

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

    Indian Academy of Sciences (India)

    Unknown

    Deprotonation of the parent CrIII-complexes and their reactions with H3BO3 have been investigated by potentiometric method ... of their metal complexes have considerable biological relevance. Although these ligands ... Purity of the complexes formed was checked by elemental analysis and spectral measurements (table ...

  17. Synthesis and evaluation of borates derived from boric acid for fire and decay protections

    Science.gov (United States)

    George Chen

    1999-01-01

    The degradation of wood by decay, fire and UV constitutes the three major losses of wood products in use. Commercial wood preservatives including chromated copper arsenate(CCA) and pentachlorophenol(penta) can only protect wood from decay. Dual protections of wood against decay and fire or decay and UV if acheivable are more desirable. Many phosphorus and boron...

  18. 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.

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

    Indian Academy of Sciences (India)

    Unknown

    complexes. G N MUKHERJEE* and ANSUMAN DAS. Department of Chemistry, University of Calcutta, University College of. Science, 92, Acharya Prafulla Chandra Road, Kolkata 700 009, India e-mail: gmchem@rediffmail.com. MS received 24 ...

  20. Effects of boron and gibberellic acid on in vitro pollen germination of ...

    African Journals Online (AJOL)

    ONOS

    2010-08-09

    Aug 9, 2010 ... study the various factors that affect the pollen viability. In vitro pollen germination rates are considered the best indicator of pollen viability (Shivanna et al., 1991). Most researchers advise on the use of sucrose solution as pollen germination media. Besides boric acid, calcium, gibberellic acid, agar, etc. may ...

  1. Effects of boron and gibberellic acid on in vitro pollen germination of ...

    African Journals Online (AJOL)

    This study was conducted on male pistachio cultivars which consisted of Uygur, Atli, Kaska, Sengel and Kavak to study the influence of boron and gibberellin on pollen germination in vitro. Pollen was sown in germination media that included 20% sucrose, 10, 25, 50, 75 and 100 ppm boric acid (H3BO3) and gibberellic acid ...

  2. 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

  3. U.S. EPA, Pesticide Product Label, WHITMIRE PT 243 BORIC ACID BAIT, 07/19/1990

    Science.gov (United States)

    2011-04-14

    ... building~, n~ con.truction, indu.trial pl.nt., the.ter., .hip., bo.t., tr.in., y.ch~.;.rap~;·:· bile_h_ •• _bu ... r.1i4tnt: •• .ill.' •• ' which .xpo •• el food or f.eel i. h.lel. ...

  4. Complexion of Boric Acid with 2-Deoxy-D-glucose (DG) as a novel boron carrier for BNCT

    OpenAIRE

    Akan, Zafer; Demiroglu, Hasan; Avcibasi, Ugur; Oto, Gokhan; Ozdemir, Hulya; Deniz, Sabahattin; Basak, Ali Sadi

    2014-01-01

    Objective: Boron neutron capture therapy (BNCT) is an intensive research area for cancer researchers. Especially the side effects and inabilities of conventional therapies in some cases, directs researchers to find out a new cancer therapy methods such as BNCT. One of three important problem of BNCT is targeting of boron to tumor tissue. Borono Phenyl Alanine (BPA) and Borono Sodium Borocaptate (BSH) are already using in clinical studies as boron carriers. New boron carriers are searching fo...

  5. 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%.

  6. 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.

  7. Gas chromatography mass spectrometric quantitative determination of product distribution of paper pyrolysis with solid acids at low temperature

    International Nuclear Information System (INIS)

    Perveen, S.; Hussain, Z.

    2009-01-01

    Paper was pyrolyzed at low temperature (300 degree C) both in the absence and presence of catalysts. The liquid products were collected and characterized by using GC/MS. Boric acid and aluminum sulphate acting as catalysts were found to alter the relative concentration and nature of the product due to depolymerizing, polarizing and free radical stabilizing properties. Boric acid was found to decrease the amount of anhydro sugars and favors the formation of esters, ketones and carboxylic acids. Aluminum sulphate favored the formation of furan carboxaldehyde, phenols and other cyclic compounds The cracking of paper and formation of new compounds was facilitated by vacant orbital of the catalyst. Therefore change in concentration of catalyst also changed the nature and concentration of the products. These observations are explained on the basis of the chemical nature of these compounds in this paper. (author)

  8. Utilization of Negative Ion ESI-MS and Tandem Mass Spectrometry to Detect and Confirm the NADH-Boric Acid Complex

    Science.gov (United States)

    Kim, Danny H.; Eckhert, Curtis D.; Faull, Kym F.

    2011-01-01

    Mass spectrometry (MS) is a powerful analytical technique that is now widely used in the chemical, physical, engineering, and life sciences, with rapidly growing applications in many areas including clinical, forensic, pharmaceutical, and environmental fields. The increase in use of MS in both academic and industrial settings for research and…

  9. General method for calculation of hydrogen-ion concentration in multicomponent acid-base mixtures.

    Science.gov (United States)

    Ventura, D A; Ando, H Y

    1980-08-01

    A generalized method for the rapid evaluation of complicated ionic equilibria in terms of the hydrogen-ion concentration was developed. The method was based on the derivation of a single general equation that could be used to evaluate any mixture. A tableau method also was developed which allowed calculation of the numerical solution to the general equation without computer analysis or graphical or intuitive approximations. Examples illustrating the utility of the method are presented. These examples include a mixture of barbital, citric acid, boric acid, monobasic sodium phosphate, and sodium hydroxide. Calculated hydrogen-ion concentrations showed good agreement with experimental values for simple and complex solutions. The major advantages of the method are its simplicity and the obtainment of numerical solutions without initial approximations in the calculations. However, activity corrections are not included in the calculations.

  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. 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)

  14. 40 CFR 415.281 - Specialized definitions.

    Science.gov (United States)

    2010-07-01

    ..., abbreviations and methods of analysis set forth in 40 CFR part 401 shall apply to this subpart. (b) The term product shall mean boric acid. ... AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Boric Acid Production...

  15. Folic Acid

    Science.gov (United States)

    Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

  16. Biofilm-associated indole acetic acid producing bacteria and their impact in the proliferation of biofilm mats in solar salterns

    Digital Repository Service at National Institute of Oceanography (India)

    Kerkar, S.; Raiker, L.; Tiwari, A.; Mayilraj, S.; Dastager, S.

    ., yeast extract 1.0 g., ferric chloride 0.1 g., sodium chloride 19.45 g., magnesium chloride 8.8 g., sodium sulphate 3.24 g., calcium chloride 1.8 g., potassium chloride 0.55 g., sodium sulphate 3.24 g., potassium bromide 0.88 g., sodium bicarbonate 0....16 g., strontium chloride 0.034 g., boric acid 0.022 g., sodium silicate 0.004 g., sodium fluoride 0.0024 g., ammonium nitrate 0.0016 g., disodium phosphate 0.008 g., agar 2.0 g., saltern water 1 L, pH 7.6 ± 0.2) and nutrient agar (NA) plates...

  17. Electrolyte for phosphoric acid fuel cell. Rinsangata nenryo denchi no denkaieki

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Y.; Uede, M.; Yamaken, H. (Yamaha Motor Co. Ltd., Shizuoka (Japan))

    1991-02-14

    When the phosphoric fuel cell is used in cold districts, the electrolyte used in the cell solidifies and freezes because its freezing point is high, and the cell can not be used any more. The object of this invention is to provide a fuel cell which does not freeze even the cell is shutdown in low temperature environment by adding non-conjugating inorganic salt to strong phosphoric acid to lower the freezing point. The phosphoric acid used in accordance with this invention is desirable generally to be of 80 to 105% if calculated in terms of orthophosphoric acid to maintain the cell performance. As the negative ions constituting the non-conjugating inorganic salt, sulphate ion, carbonate ion, silicate ion, and boric acid ion are desirable. In concrete, ZnSO{sub 4}, NiSO{sub 4}, Na{sub 2}SO{sub 4}, BeSO{sub 4}, CdSO{sub 4}, CoSO{sub 4}, FeSO{sub 4}, K{sub 2}CO{sub 3}, Na{sub 2}CO{sub 3}, CaCO{sub 3}, MgCO{sub 3}, K{sub 2}SiO{sub 3}, Na{sub 2}B{sub 4}O{sub 7}, etc. can be quoted. Excessive addition of inorganic salt results rather in the precipitation of the added inorganic salt to cause freezing, and addition of 20wt% or less is desirable. 1 fig.

  18. 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...

  19. 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 ...

  20. Obeticholic Acid

    Science.gov (United States)

    Obeticholic acid is used alone or in combination with ursodiol (Actigall, Urso) to treat primary biliary cholangitis (PBC; a ... were not treated successfully with ursodiol alone. Obeticholic acid is in a class of medications called farnesoid ...

  1. 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 ...

  2. 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 ...

  3. Mefenamic Acid

    Science.gov (United States)

    Mefenamic acid is used to relieve mild to moderate pain, including menstrual pain (pain that happens before or during a menstrual period). Mefenamic acid is in a class of medications called NSAIDs. ...

  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. Okadaic acid

    DEFF Research Database (Denmark)

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

    2014-01-01

    Okadaic acid (OA) is a polyether fatty acid produced by marine dinoflagellates and the causative agent of diarrhetic shellfish poisoning. The effect of OA on apical endocytosis in the small intestine was studied in organ cultured porcine mucosal explants. Within 0.5-1 h of culture, the toxin caused...... 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....

  6. Aristolochic Acids

    Science.gov (United States)

    ... often used as herbal medicines or in other botanical products in the United States and abroad. Aristolochic ... individuals with kidney or renal disease who consumed botanical products containing aristolochic acids. Animal Studies The findings ...

  7. Zoledronic acid.

    Science.gov (United States)

    Coleman, Robert; Burkinshaw, Roger; Winter, Matthew; Neville-Webbe, Helen; Lester, Jim; Woodward, Emma; Brown, Janet

    2011-01-01

    Both bone metastases and fragility fractures due to bone loss result in considerable morbidity affecting quality of life and independence as well as placing complex demands on healthcare resources. Zoledronic acid is a widely used intravenous bisphosphonate that reduces this skeletal morbidity in both benign and malignant conditions. The incidence, clinical importance and prevention strategies to minimize side effects associated with the use of zoledronic acid are discussed with a particular focus on use in oncology where intensive monthly scheduling is required. This potentially increases the risk for adverse events over the 6-12 monthly administration used to treat benign bone diseases. A detailed understanding of the generally favorable safety profile of zoledronic acid, but particularly the potential for renal dysfunction and osteonecrosis of the jaw. When compared to many other therapies, especially in the cancer setting, the severity of adverse events related to zoledronic acid is generally mild and, with the exception of the acute phase response causing transient fever, myalgia and bone pain, side effects are infrequent. Thus, the benefits of treatment with zoledronic acid within its licensed indications almost always outweigh the risks.

  8. Electrophoretically mediated microanalysis for simultaneous on-capillary derivatization of standard amino acids followed by micellar electrokinetic capillary chromatography with laser-induced fluorescence detection.

    Science.gov (United States)

    Celá, Andrea; Mádr, Aleš; Glatz, Zdeněk

    2017-05-26

    Amino acids are crucial compounds involved in most biochemical processes essential for life. Since their dynamic turnover reflects the actual physiology of the cell/organism, a turnover assessment may provide valuable information related to multiple physiological and pathophysiological conditions. The sensitive determination of amino acids is predominantly associated with their derivatization which might be laborious, time-consuming and difficult to standardize. However, capillary electrophoresis offers the automatic injection and mixing of reactants, incubation of the reaction mixture, separation and detection of the reaction products in one on-capillary procedure. Among the on-capillary mixing strategies, electrophoretically mediated microanalysis (EMMA) is superior in terms of mixing efficiency. In this paper, we present an optimization of EMMA for the simultaneous derivatization of standard amino acids by naphthalene-2,3-dicarboxaldehyde/NaCN and its application to targeted human embryo metabolomics. For such a purpose, novel separation conditions were developed involving the background electrolyte, comprised of 73mM sodium dodecyl sulfate, 6.7 % (v/v) 1-propanol, 0.5mM (2-hydroxypropyl)-β-cyclodextrin and 135mM boric acid/sodium hydroxide buffer (pH 9.00). Finally, the optimized EMMA was compared to a fundamentally different mixing strategy, namely the transverse diffusion of laminar flow profiles, and proved to be also suitable for human plasma analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Acid Rain

    Science.gov (United States)

    Bricker, Owen P.; Rice, Karen C.; Dietrich, W.E.; Sposito, Garrison

    1997-01-01

    Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

  10. 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

  11. Salicylhydroxamic acids

    Indian Academy of Sciences (India)

    to as topological indices, can be used for establishing QSAR of interest in pharmacology. A number of successful QSAR studies were made 4 based on Wms by means of which we can determine the ways in which the structural features of SHA and SHA derivatives influence the course of nucleic acid synthesis in a tumour ...

  12. 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.'

  13. 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].

  14. Dry lubricant films for aluminum forming.

    Energy Technology Data Exchange (ETDEWEB)

    Wei, J.; Erdemir, A.; Fenske, G. R.

    1999-03-30

    During metal forming process, lubricants are crucial to prevent direct contact, adhesion, transfer and scuffing of workpiece materials and tools. Boric acid films can be firmly adhered to the clean aluminum surfaces by spraying their methanol solutions and provide extremely low friction coefficient (about 0.04). The cohesion strengths of the bonded films vary with the types of aluminum alloys (6061, 6111 and 5754). The sheet metal forming tests indicate that boric acid films and the combined films of boric acid and mineral oil can create larger strains than the commercial liquid and solid lubricants, showing that they possess excellent lubricities for aluminum forming. SEM analyses indicate that boric acid dry films separate the workpiece and die materials, and prevent their direct contact and preserve their surface qualities. Since boric acid is non-toxic and easily removed by water, it can be expected that boric acid films are environmentally friendly, cost effective and very efficient lubricants for sheet aluminum cold forming.

  15. Maleopimaric acid acetic acid solvate

    OpenAIRE

    Zhang, Meng; Zhou, Yong-hong; Guo, Xiao-xin; Hu, Li-hong

    2009-01-01

    The title compound, C24H32O5·C2H4O2, is a derivative of abietic acid. The two fused and unbridged cyclohexane rings have chair conformations and the anhydride ring is planar. Of the other three six-membered rings, two have boat conformations and one has a twist-boat conformation. The crystal structure is stabilized by intermolecular O—H...O and C—H...O hydrogen bonds.

  16. Folic Acid and Pregnancy

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Folic Acid and Pregnancy KidsHealth / For Parents / Folic Acid and ... conception and during early pregnancy . What Is Folic Acid? Folic acid, sometimes called folate, is a B ...

  17. In vitro pollen quantity, viability and germination tests in quince

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... The germination rates in different sucrose and boric acid concentrations in 1% agar changed from 0 ('Limon' in 0% sucrose) to 91.7% ('Ege 2' in 20% sucrose) and from 32.7 (Quince A in 0 mg/L boric acid) to 94.9% ('Ege 22' in 100 mg/L boric acid), respectively. Key words: Cydonia oblonga, pollen, viability ...

  18. Screening of systemic fungicides and biochemicals against seed ...

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... chemicals salicylic acid and boric acid with different concentrations were used in this experiment. Ridomil gold (metalaxyl+mancozeb). 20-30-40 mg/10 ml, bavistin (Carbendazim) 20-30-40 mg/10 ml, score (difenoconazole) 5-6-7 µl/10 ml, disprin (salicylic acid) 20-30-. 40 mg/10 ml, and borax (boric acid) ...

  19. Dehydroabietic acid

    Directory of Open Access Journals (Sweden)

    Xiao-Ping Rao

    2009-10-01

    Full Text Available The title compound [systematic name: (1R,4aS,10aR-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthrene-1-carboxylic acid], C20H28O2, has been isolated from disproportionated rosin which is obtained by isomerizing gum rosin with a Pd-C catalyst.. Two crystallographically independent molecules exist in the asymmetric unit. In each molecule, there are three six-membered rings, which adopt planar, half-chair and chair conformations. The two cyclohexane rings form a trans ring junction with the two methyl groups in axial positions. The crystal structure is stabilized by intermolecular O—H...O hydrogen bonds.

  20. 40 CFR 180.920 - Inert ingredients used pre-harvest; exemptions from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... per acre Preservative/stabilizer Boric acid Sequestrant Buffalo gourd root powder (Cucurbita foetidissima root powder); or, Zucchini juice (Cucurbita pepo juice) or Hawkesbury melon Citrullus lanatus. No...

  1. [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.

  2. 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 ...

  3. 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 this page, please enable JavaScript. The uric acid urine test measures the level of uric acid ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. 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.

  8. 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

  9. 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.

  10. Toxicity of adipic acid.

    Science.gov (United States)

    Kennedy, Gerald L

    2002-05-01

    Adipic acid has very low acute toxicity in rats with an LD50 > 5000 mg/kg. Adipic acid produced mild to no skin irritation on intact guinea pig skin as a 50% concentration in propylene glycol; it was not a skin sensitizer. Adipic acid caused mild conjunctival irritation in washed rabbit eyes; in unwashed rabbit eyes, there was mild conjunctival irritation, minimal iritis, but no corneal effects. Adipic acid dust may irritate the mucous membranes of the lungs and nose. In a 2-year feeding study, rats fed adipic acid at concentrations up to 5% in the diet exhibited only weight loss. Adipic acid is not genetically active in a wide variety of assay systems. Adipic acid caused no developmental toxicity in mice, rats, rabbits, or hamsters when administered orally. Adipic acid is partially metabolized in humans; the balance is eliminated unchanged in the urine. Adipic acid is slightly to moderately toxic to fish, daphnia, and algae in acute tests.

  11. Acid Thunder: Acid Rain and Ancient Mesoamerica

    Science.gov (United States)

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  12. Влияние нанопорошка алюминия на термическую стойкость и механические характеристики эпоксидных композитов

    OpenAIRE

    Мельникова, Т. В.; Фрянова, К. О.; Путенпуракалчира, В. М.

    2015-01-01

    The thermal and mechanical characteristics of epoxy composites were studied. Epoxy composites were prepared using epoxy resin ED-20, aluminum nanopowders and boric acid fine powder as flame-retardant filler. It was found that the incorporation of aluminum nanopowders and boric acid fine powder enhances the thermal stability and mechanical characteristics of epoxy composites.

  13. Clean and cost-effective dry boundary lubricants for aluminum forming.

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, A.; Fenske, G. R.

    1997-12-05

    Preliminary research in our laboratory has demonstrated that boric acid is an effective lubricant with an unusual capacity to reduce sliding fiction (providing friction coefficients as low as 0.02) and wear of metallic and ceramic materials. More recent studies have revealed that water or methanol solutions of boric acid can be used to prepare strongly bonded layers of boric acid on aluminum surfaces. It appears that boric acid molecules have a strong tendency to bond chemically to the naturally oxidized surfaces of aluminum and its alloys and to make these surfaces very slippery. Recent metal formability tests indicated that the boric acid films formed on aluminum surfaces by spraying or dipping worked quite well; improving draw scale performance by 58 to 75%. These findings have increased the prospect that boric acid can be formulated and optimized as an effective boundary lubricant and used to solve the friction, galling, and severe wear problems currently encountered in cold-forming of aluminum products. Accordingly, the major goal of this paper is to demonstrate the usefulness and lubrication capacity of thin boric acid films formed on aluminum surfaces by simple dipping or spraying processes and to describe the lubrication mechanisms under typical metal forming conditions. We will also examine the nature of chemical bonding between boric acid and aluminum surfaces and develop new ways to optimize its performance as an effective boundary lubricant.

  14. Effect of condensation product of glycyl–glycine and furfural on ...

    Indian Academy of Sciences (India)

    Unknown

    base metal by zinc coating obtained from developed electrolyte. ... Sorkhabi et al 2005) and studied in a basic zinc sulphate bath. Among these, the .... solution. 3.1f Effect of boric acid: The aim of boric acid addition to the electroplating bath is to control the variation of H+ ion concentration in the bath solution. To see the ...

  15. 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

  16. Amino Acid Metabolism Disorders

    Science.gov (United States)

    ... acids are "building blocks" that join together to form proteins. If you have one of these disorders, your body may have trouble breaking down certain amino acids. Or there may be a problem getting the ...

  17. Uric acid - blood

    Science.gov (United States)

    ... acid in blood Images Blood test Uric acid crystals References Edwards NL. Crystal deposition diseases. In: Goldman L, Schafer AI, eds. ... M. is among the first to achieve this important distinction for online health information and services. Learn ...

  18. 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, ...

  19. Pantothenic acid and biotin

    Science.gov (United States)

    ... gov/ency/article/002410.htm Pantothenic acid and biotin To use the sharing features on this page, please enable JavaScript. Pantothenic acid and biotin are types of B vitamins. They are water- ...

  20. Acid-fast stain

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003766.htm Acid-fast stain To use the sharing features on this page, please enable JavaScript. The acid-fast stain is a laboratory test that determines ...

  1. 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 ...

  2. 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 ...

  3. 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 ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. Valproic Acid and Pregnancy

    Science.gov (United States)

    ... live chat Live Help Fact Sheets Share Valproic Acid Monday, 01 January 2018 In every pregnancy, a ... This sheet talks about whether exposure to valproic acid may increase the risk for birth defects over ...

  8. 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 ...

  9. Sulfuric acid poisoning

    Science.gov (United States)

    Sulfuric acid is a very strong chemical that is corrosive. Corrosive means it can cause severe burns and ... or mucous membranes. This article discusses poisoning from sulfuric acid. This article is for information only. Do NOT ...

  10. Phase equilibria in systems of formates with isobutyl alcohol

    International Nuclear Information System (INIS)

    Seselkin, I.V.; Garber, Y.N.; Mironenko, V.F.

    1985-01-01

    The borate method, based on esterification with boric acid, was proposed for isolation of isobutyl alchohol. The method inv olves formation and hydrolysis of alkyl borate esters; in particular, formation and hydrolysis of triisobutyl borate. Esterification of isobutyl alcohol with boric acid is a reversible equilibrium reaction, and therefore in order to obtain high yields the water formed in the reaction must be removed. The presence of other organic compounds, which do not react with boric acid, in the mixture does not affect esterification of the alcohol. The reaction proceeds at 95-100 0 under atmospheric pressure. It was found that up to 97% of the isobutyl alcohol combines with boric acid. The resultant triisobutyl borate is isolated by ordinary distillation and then hydrolyzed to form boric acid and isobutyl alcohol

  11. A novel inorganic–organic hybrid borate, poly{[Na2(C4H2O4(H3BO3(H2O4]·H3BO3}

    Directory of Open Access Journals (Sweden)

    Zhi-Dong Shao

    2010-11-01

    Full Text Available The structure of the title compound, catena-poly[[[di-μ-aqua-μ-fumarato-μ-(boric acid-disodium]-di-μ-aqua] boric acid monosolvate], contains two crystallographically independent Na+ cations, each being six-coordinated by one fumarate O atom, one boric acid O atom and four water O atoms in a distorted octahedral geometry. Adjacent [NaO2(OH24] units share edges and are linked into chains propagating parallel to [100]. The free boric acid molecules are connected to the chains through strong intermolecular O—H...O hydrogen bonds. Additional O—H...O hydrogen bonds between the water molecules, the free and coordinated boric acid molecules and the fumarate anion lead to the formation of a three-dimensional supramolecular structure. With the exception of the two water molecules, all other atoms lie on mirror planes.

  12. 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…

  13. 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)…

  14. 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

  15. 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/ ...

  16. 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...

  17. Amino acid analysis

    Science.gov (United States)

    Winitz, M.; Graff, J. (Inventor)

    1974-01-01

    The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

  18. 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

  19. Molecular Interaction of Pinic Acid with Sulfuric Acid

    DEFF Research Database (Denmark)

    Elm, Jonas; Kurten, Theo; Bilde, Merete

    2014-01-01

    from the corresponding ΔG values. The first two additions of sulfuric acid to pinic acid are found to be favorable with ΔG values of -9.06 and -10.41 kcal/mol. Addition of a third sulfuric acid molecule is less favorable and leads to a structural rearrangement forming a bridged sulfuric acid-pinic acid...... without the further possibility for attachment of either sulfuric acid or pinic acid. This suggests that pinic acid cannot be a key species in the first steps in nucleation, but the favorable interactions between sulfuric acid and pinic acid imply that pinic acid can contribute to the subsequent growth...

  20. [Biosynthesis of adipic acid].

    Science.gov (United States)

    Han, Li; Chen, Wujiu; Yuan, Fei; Zhang, Yuanyuan; Wang, Qinhong; Ma, Yanhe

    2013-10-01

    Adipic acid is a six-carbon dicarboxylic acid, mainly for the production of polymers such as nylon, chemical fiber and engineering plastics. Its annual demand is close to 3 million tons worldwide. Currently, the industrial production of adipic acid is based on the oxidation of aromatics from non-renewable petroleum resources by chemo-catalytic processes. It is heavily polluted and unsustainable, and the possible alternative method for adipic acid production should be developed. In the past years, with the development of synthetic biology and metabolic engineering, green and clean biotechnological methods for adipic acid production attracted more attention. In this study, the research advances of adipic acid and its precursor production are reviewed, followed by addressing the perspective of the possible new pathways for adipic acid production.

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. DEOXYRIBONUCLEIC ACID HYBRIDS OF ACETIC ACID BACTERIA

    Science.gov (United States)

    De Ley, J.; Friedman, S.

    1964-01-01

    De Ley, J. (State University, Ghent, Belgium), and S. Friedman. Deoxyribonucleic acid hybrids of acetic acid bacteria. J. Bacteriol. 88:937–945. 1964.—Deuterated N15-labeled deoxyribonucleic acid (DNA) from Acetobacter aceti (mesoxydans 4) forms hybrids with ordinary DNA from other species of this genus (A. xylinum, A. pasteurianus, A. estunensis, and possibly A. xylinoides) when the guanine plus cytosine base composition does not vary by more than 1 to 2%. Beyond this limit (A. aceti Ch31 and A. muciparus 5) no hybrids are formed. The hybrids are apparently derived from an asymmetrical part of the compositional distribution. The results lend strength to the concept of a genetic species rather than to a division of a genus into sharply separated species, based on small phenotypic differences. Taxonomic implications are discussed. PMID:14219057

  7. 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.

  8. 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...

  9. Recovery of organic acids

    Science.gov (United States)

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  10. The acid rain primer

    International Nuclear Information System (INIS)

    Nugent, O.

    2006-10-01

    Acid rain continues to be a major problem in North America, and particularly in eastern Canada. This report introduced the topic of acid rain and discussed its formation, measurement, sources, and geographic distribution. The major sources of sulphur dioxide in Canada are smelting metals, burning coal for electrical power generation, industrial emissions (e.g., pulp and paper, petroleum and aluminum industry), and oil and gas extraction and refining. In Canada, the largest source of nitrogen oxide is the burning of fossil fuels by the transportation sector. Problem areas for acid rain in Canada were identified. The effects of acid rain were examined on lakes and aquatic ecosystems, forests and soils, human-made structures and materials, human health, and on visibility. Acid rain policies and programs were then presented from a historical and current context. Ecosystem recovery from acid rain was discussed with reference to acid rain monitoring, atmospheric response to reductions in acid-causing emissions, and ecosystem recovery of lakes, forests, and aquatic ecosystems. Challenges affecting ecosystem recovery were also presented. These challenges include drought and dry weather, decrease of base cations in precipitation, release of sulphate previously stored in soil, mineralization and immobilization of sulphur/sulphates. Last, the report discussed what still needs to be done to improve the problem of acid rain as well as future concerns. These concerns include loss of base cations from forested watersheds and nitrogen deposition and saturation. 21 refs., 2 tabs., 17 figs

  11. Folic Acid Quiz

    Science.gov (United States)

    ... to Other Health Outcomes Folic Acid Fortification and Supplementation Neural Tube Defects Surveillance References Data and Statistics Research Birth Defects COUNT Articles & Key Findings Recommendations Links to ...

  12. Recovery of organic acids

    Science.gov (United States)

    Verser, Dan W [Menlo Park, CA; Eggeman, Timothy J [Lakewood, CO

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  13. 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.

  14. Chlorogenic acid and caffeic acid are absorbed in humans

    OpenAIRE

    Olthof, M.R.; Hollman, P.C.H.; Katan, M.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 absorption of chlorogenic acid and caffeic acid in humans are lacking. We determined the absorption of chlorogenic acid and caffeic acid in a cross-over study with 4 female and 3 male healthy ileo...

  15. 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.

  16. Science of acid rain

    International Nuclear Information System (INIS)

    Mizoguchi, Tsuguo

    1992-01-01

    In this report, the mechanism of forming acid rain in the atmosphere and the process of its fall to ground, the mechanism of withering forests by acid substances, and the process of acidifying lakes and marshes are explained. Moreover, the monitoring networks for acid rain and the countermeasures are described. Acid rain is the pollution phenomena related to all environment, that is, atmosphere, hydrosphere, soilsphere, biosphere and so on, and it is a local environmental pollution problem, and at the same time, an international, global environmental pollution problem. In Japan, acid rain has fallen, but the acidification of lakes and marshes is not clear, and the damage to forests is on small scale. However in East Asia region, the release of sulfur oxides and nitrogen oxides is much, and the increase of the effects of acid rain is expected. It is necessary to devise the measures for preventing the damage due to acid rain. The global monitoring networks of World Meteorological Organization and United Nations Environment Program, and those in Europe, USA and Japan are described. The monitoring of acid rain in Japan is behind that in Europe and USA. (K.I.)

  17. 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 ...

  18. 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...

  19. 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....

  20. 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;…

  1. 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, chlor...

  2. 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....

  3. 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....

  4. 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....

  5. Acid dissociation characteristics of humic acids

    International Nuclear Information System (INIS)

    Tochiyama, Osamu; Sakakibara, Tetsuro; Inoue, Yasushi

    1995-01-01

    Based on the results from potentiometric titrations carried out on polyacrylic acid and some commercially available humic acids, the equation for the proton dissociation of weak polymeric acids is proposed to be K app (H + )α/(1-α) = K 1/2 {(1-α)/α}((Na + )/(Na + ) s ), where α is the degree of dissociation, K 1/2 is the dissociation constant at α = 1/2, and the brackets with subscript s denote the concentration at the surface of the polymer. This equation has been derived on the assumptions: (i) Each polymer molecule is a polybasic acid (H N R N ) having different acidic sites with K values from K 1 to K N . (ii) Binding energies of protons on these sites are all equal. (iii) The ratios of the dissociation constants of H N-i R N i- and H N-j R N j- is expressed by K i /K j = {(N-i+1)/i}/{(N-j+1)/j} since the probabilities to release or bind a proton are proportional to the numbers of protons or numbers of available anionic sites on the polymer. (iv) The effective concentration of protons at the surface of the polymer ((H + ) s ) is related by (H + ) s /(H + ) = (Na + ) s /(Na + ), where (Na + ) s can be estimated by the relation, (Na + ) s = (Cl - ) s + (R - ) s (where (R - ) s Σi(H N-i R N i- )). This leads to (Na + ) s ≅ (Cl - ) s , which in turn leads to (Na + ) s ≅ (Na + ) at high ionic strength and (Na + ) s ≅ (R - ) s = C R α at low ionic strength. (author)

  6. 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

  7. Production of shikimic acid.

    Science.gov (United States)

    Ghosh, Saptarshi; Chisti, Yusuf; Banerjee, Uttam C

    2012-01-01

    Shikimic acid is a key intermediate for the synthesis of the antiviral drug oseltamivir (Tamiflu®). Shikimic acid can be produced via chemical synthesis, microbial fermentation and extraction from certain plants. An alternative production route is via biotransformation of the more readily available quinic acid. Much of the current supply of shikimic acid is sourced from the seeds of Chinese star anise (Illicium verum). Supply from star anise seeds has experienced difficulties and is susceptible to vagaries of weather. Star anise tree takes around six-years from planting to bear fruit, but remains productive for long. Extraction and purification from seeds are expensive. Production via fermentation is increasing. Other production methods are too expensive, or insufficiently developed. In the future, production in recombinant microorganisms via fermentation may become established as the preferred route. Methods for producing shikimic acid are reviewed. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. 2-Methylaspartic acid monohydrate

    Directory of Open Access Journals (Sweden)

    Ray J. Butcher

    2013-12-01

    Full Text Available The title compound, C5H9NO4·H2O, is an isomer of the α-amino acid glutamic acid that crystallizes from water in its zwitterionic form as a monohydrate. It is not one of the 20 proteinogenic α-amino acids that are used in living systems and differs from the natural amino acids in that it has an α-methyl group rather than an α-H atom. In the crystal, an O—H...O hydrogen bond is present between the acid and water molecules while extensive N—H...O and O—H...O hydrogen bonds link the components into a three-dimensional array.

  9. 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

  10. 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

  11. Trans Fatty Acids

    Science.gov (United States)

    Doyle, Ellin

    1997-09-01

    Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.

  12. Sulfuric Acid on Europa

    Science.gov (United States)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain. This image is based on data gathered by Galileo's near infrared mapping spectrometer.Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks. Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  13. 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....

  14. 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....

  15. 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 good...... excellent results in infected eczema by addressing both inflammation and infection. A new lipid-rich combination formulation provides an extra moisturizing effect. Development of resistance to fusidic acid has remained generally low or short-lived and can be minimized by restricting therapy to no more than...

  16. octadecenoic acid in tomato

    African Journals Online (AJOL)

    User

    octadecenoic acid which is proba- bly involved in plant defense responses is synthesized in tomato fruits and subjected to metabo- lism. Its catabolism or conversion was thus further characterized. The endogenous level of.

  17. Folic acid in diet

    Science.gov (United States)

    Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. National Academies Press. Washington, DC, 1998. PMID: 23193625 ...

  18. 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.

  19. 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

  20. Hydrofluoric acid poisoning

    Science.gov (United States)

    ... mouth (intubation), and breathing machine (ventilator) Blood and urine tests Camera down the throat to see burns in the esophagus and the stomach (endoscopy) Fluids through a vein (IV) Magnesium and calcium solutions to neutralize the acid Medicines ...

  1. 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...

  2. Methylmalonic Acid Test

    Science.gov (United States)

    ... and Iron-binding Capacity (TIBC, UIBC) Trichomonas Testing Triglycerides Troponin Tryptase Tumor Markers Uric Acid Urinalysis Urine ... very small amounts and is necessary for human metabolism and energy production. In one step of metabolism, ...

  3. Neutron Nucleic Acid Crystallography.

    Science.gov (United States)

    Chatake, Toshiyuki

    2016-01-01

    The hydration shells surrounding nucleic acids and hydrogen-bonding networks involving water molecules and nucleic acids are essential interactions for the structural stability and function of nucleic acids. Water molecules in the hydration shells influence various conformations of DNA and RNA by specific hydrogen-bonding networks, which often contribute to the chemical reactivity and molecular recognition of nucleic acids. However, X-ray crystallography could not provide a complete description of structural information with respect to hydrogen bonds. Indeed, X-ray crystallography is a powerful tool for determining the locations of water molecules, i.e., the location of the oxygen atom of H2O; however, it is very difficult to determine the orientation of the water molecules, i.e., the orientation of the two hydrogen atoms of H2O, because X-ray scattering from the hydrogen atom is very small.Neutron crystallography is a specialized tool for determining the positions of hydrogen atoms. Neutrons are not diffracted by electrons, but are diffracted by atomic nuclei; accordingly, neutron scattering lengths of hydrogen and its isotopes are comparable to those of non-hydrogen atoms. Therefore, neutron crystallography can determine both of the locations and orientations of water molecules. This chapter describes the current status of neutron nucleic acid crystallographic research as well as the basic principles of neutron diffraction experiments performed on nucleic acid crystals: materials, crystallization, diffraction experiments, and structure determination.

  4. 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...

  5. [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.

  6. 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

  7. Inhibitory effect of ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo; Wan, Wei; Wang, Jianlong [Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084 (China)

    2008-12-15

    The inhibitory effect of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production by mixed cultures was investigated in batch tests using glucose as substrate. The experimental results showed that, at 35 C and initial pH 7.0, during the fermentative hydrogen production, the substrate degradation efficiency, hydrogen production potential, hydrogen yield and hydrogen production rate all trended to decrease with increasing added ethanol, acetic acid, propionic acid and butyric acid concentration from 0 to 300 mmol/L. The inhibitory effect of added ethanol on fermentative hydrogen production was smaller than those of added acetic acid, propionic acid and butyric acid. The modified Han-Levenspiel model could describe the inhibitory effects of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production rate in this study successfully. The modified Logistic model could describe the progress of cumulative hydrogen production. (author)

  8. Amino acids in the sedimentary humic and fulvic acids

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    Humic and fulvic acids isolated from a few sediment samples from Arabian Sea and Bay of Bengal were analysed for total hydrolysable amino acids concentration and their composition. The amono acids content of fulvic acids was higher than in the humic...

  9. 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...

  10. Amino-acid contamination of aqueous hydrochloric acid.

    Science.gov (United States)

    Wolman, Y.; Miller, S. L.

    1971-01-01

    Considerable amino-acid contamination in commercially available analytical grade hydrochloric acid (37% HCl) was found. One bottle contained 8,300 nmol of amino-acids per liter. A bottle from another supplier contained 6,700 nmol per liter. The contaminants were mostly protein amino-acids and several unknowns. Data on the volatility of the amino-acids during HCl distillation were also obtained.

  11. 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.

  12. 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)

  13. Diffusion-Limited Aggregation in Potato Starch and Hydrogen Borate Electrolyte System

    Directory of Open Access Journals (Sweden)

    Tuhina Tiwari

    2013-01-01

    Full Text Available Natural growth of diffusion-limited aggregate (DLA, without any external stimuli, in boric acid doped starch system is reported here. Fractals grown were confirmed to be of diffusion-limited aggregate (DLA pattern having fractal dimension ~1.49. Effect of substrate and humidity on growth pattern has also been discussed. The existence of a different vibration band of H3BO3 in FTIR confirmed that growth structures are related to boric acid. XRD pattern has shown broad peak along with some sharp peaks. Broad peak is related to starch’s amorphous nature, as where intense sharp peaks are due to boric acid.

  14. Biodegradation of Cyanuric Acid

    Science.gov (United States)

    Saldick, Jerome

    1974-01-01

    Cyanuric acid biodegrades readily under a wide variety of natural conditions, and particularly well in systems of either low or zero dissolved-oxygen level, such as anaerobic activated sludge and sewage, soils, muds, and muddy streams and river waters, as well as ordinary aerated activated sludge systems with typically low (1 to 3 ppm) dissolved-oxygen levels. Degradation also proceeds in 3.5% sodium chloride solution. Consequently, there are degradation pathways widely available for breaking down cyanuric acid discharged in domestic effluents. The overall degradation reaction is merely a hydrolysis; CO2 and ammonia are the initial hydrolytic breakdown products. Since no net oxidation occurs during this breakdown, biodegradation of cyanuric acid exerts no primary biological oxygen demand. However, eventual nitrification of the ammonia released will exert its usual biological oxygen demand. PMID:4451360

  15. Acid rain in Asia

    Science.gov (United States)

    Bhatti, Neeloo; Streets, David G.; Foell, Wesley K.

    1992-07-01

    Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging perception that the problem in these Western nations is nearing solution. The situation in the developing world, particularly in Asia, is much bleaker. Given the policies of many Asian nations to achieve levels of development comparable with the industrialized world—which necessitate a significant expansion of energy consumption (most derived from indigenous coal reserves)—the potential for the formation of, and damage from, acid deposition in these developing countries is very high. This article delineates and assesses the emissions patterns, meteorology, physical geology, and biological and cultural resources present in various Asian nations. Based on this analysis and the risk factors to acidification, it is concluded that a number of areas in Asia are currently vulnerable to acid rain. These regions include Japan, North and South Korea, southern China, and the mountainous portions of Southeast Asia and southwestern India. Furthermore, with accelerated development (and its attendant increase in energy use and production of emissions of acid deposition precursors) in many nations of Asia, it is likely that other regions will also be affected by acidification in the near future. Based on the results of this overview, it is clear that acid deposition has significant potential to impact the Asian region. However, empirical evidence is urgently needed to confirm this and to provide early warning of increases in the magnitude and spread of acid deposition and its effects throughout this part of the world.

  16. 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.

  17. 2-(Benzylcarbamoylnicotinic acid

    Directory of Open Access Journals (Sweden)

    Yan-Cao Mao

    2013-10-01

    Full Text Available In the title compound, C14H12N2O3, the pyridine ring is twisted with respect to the phenyl ring and the carboxylic acid group at angles of 37.1 (5 and 8.1 (3°, respectively; the phenyl ring forms a dihedral angle of 41.4 (1° with the mean plane of the C—NH—C=O fragment. An intramolecular O—H...O hydrogen bond occurs between the carboxylic acid and carbonyl groups. In the crystal, N—H...O hydrogen bonds link molecules into a supramolecular chain running along the a-axis direction.

  18. Omega-3 fatty acids: new insights into the pharmacology and biology of docosahexaenoic acid, docosapentaenoic acid, and eicosapentaenoic acid.

    Science.gov (United States)

    Davidson, Michael H

    2013-12-01

    Fish oil contains a complex mixture of omega-3 fatty acids, which are predominantly eicosapentaenoic acid (EPA), docosapentaenoic acid, and docosahexaenoic acid (DHA). Each of these omega-3 fatty acids has distinct biological effects that may have variable clinical effects. In addition, plasma levels of omega-3 fatty acids are affected not only by dietary intake, but also by the polymorphisms of coding genes fatty acid desaturase 1-3 for the desaturase enzymes that convert short-chain polyunsaturated fatty acids to long-chain polyunsaturated fatty acids. The clinical significance of this new understanding regarding the complexity of omega-3 fatty acid biology is the purpose of this review. FADS polymorphisms that result in either lower levels of long-chain omega-3 fatty acids or higher levels of long-chain omega-6 polyunsaturated fatty acids, such as arachidonic acid, are associated with dyslipidemia and other cardiovascular risk factors. EPA and DHA have differences in their effects on lipoprotein metabolism, in which EPA, with a more potent peroxisome proliferator-activated receptor-alpha effect, decreases hepatic lipogenesis, whereas DHA not only enhances VLDL lipolysis, resulting in greater conversion to LDL, but also increases HDL cholesterol and larger, more buoyant LDL particles. Overall, these results emphasize that blood concentrations of individual long-chain polyunsaturated fatty acids, which reflect both dietary intake and metabolic influences, may have independent, but also complementary- biological effects and reinforce the need to potentially provide a complex mixture of omega-3 fatty acids to maximize cardiovascular risk reduction.

  19. 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

  20. 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

  1. Oxalic acid excretion after intravenous ascorbic acid administration

    Science.gov (United States)

    Robitaille, Line; Mamer, Orval A.; Miller, Wilson H.; Levine, Mark; Assouline, Sarit; Melnychuk, David; Rousseau, Caroline; Hoffer, L. John

    2012-01-01

    Ascorbic acid is frequently administered intravenously by alternative health practitioners and, occasionally, by mainstream physicians. Intravenous administration can greatly increase the amount of ascorbic acid that reaches the circulation, potentially increasing the risk of oxalate crystallization in the urinary space. To investigate this possibility, we developed gas chromatography mass spectrometry methodology and sampling and storage procedures for oxalic acid analysis without interference from ascorbic acid and measured urinary oxalic acid excretion in people administered intravenous ascorbic acid in doses ranging from 0.2 to 1.5 g/kg body weight. In vitro oxidation of ascorbic acid to oxalic acid did not occur when urine samples were brought immediately to pH less than 2 and stored at –30°C within 6 hours. Even very high ascorbic acid concentrations did not interfere with the analysis when oxalic acid extraction was carried out at pH 1. As measured during and over the 6 hours after ascorbic acid infusions, urinary oxalic acid excretion increased with increasing doses, reaching approximately 80 mg at a dose of approximately 100 g. We conclude that, when studied using correct procedures for sample handling, storage, and analysis, less than 0.5% of a very large intravenous dose of ascorbic acid is recovered as urinary oxalic acid in people with normal renal function. PMID:19154961

  2. 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)

  3. 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.

  4. Synthesis of acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters

    Science.gov (United States)

    Moens, Luc

    2003-06-24

    A process of preparing an acid addition salt of delta-aminolevulinc acid comprising: a) dissolving a lower alkyl 5-bromolevulinate and hexamethylenetetramine in a solvent selected from the group consisting of water, ethyl acetate, chloroform, acetone, ethanol, tetrahydrofuran and acetonitrile, to form a quaternary ammonium salt of the lower alkyl 5-bromolevulinate; and b) hydrolyzing the quaternary ammonium salt with an inorganic acid to form an acid addition salt of delta-aminolevulinic acid.

  5. 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...

  6. 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.

  7. 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 ...

  8. 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.

  9. 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.

  10. 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)

  11. Hyaluronic Acid Assays

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...

  12. 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 and...

  13. and amino acids

    Indian Academy of Sciences (India)

    Unknown

    (L-Trp), were obtained from Sigma Chemical Company (USA). All the metal ions Cu(II),. Ni(II) and .... respective free amino acids show characteristic band positions, shifts and intensities, which can be correlated to ..... Financial support from the University Grants Commission, New Delhi to Prof P Rabindra. Reddy is gratefully ...

  14. [Acid hydrolysis of mandioca].

    Science.gov (United States)

    Colombo, A J; Schneiderman, B; Baruffaldi, R; Nacco, R

    1975-01-01

    The influence of time of hydrolysis, pression of the process, ratio of mass of flour and volume and concentration of the acid solution was studied in the hydrolytic processes for Cassava flour. The aim was to obtain fermentable sugars, and the results were submitted to variance analysis.

  15. Hurnic acid protein complexation

    NARCIS (Netherlands)

    Tan, W. F.; Koopal, L. K.; Weng, L. P.; van Riemsdijk, W. H.; Norde, W.

    2008-01-01

    Interactions of purified Aldrich humic acid (PAHA) with lysozyme (LSZ) are investigated. In solution LSZ is moderately positively and PAHA negatively charged at the investigated pH values. The proton binding of PAHA and of LSZ is determined by potentiometric proton titrations at various KCl

  16. Nanoclusters of Cyanuric Acid

    Indian Academy of Sciences (India)

    Hydrogen bonding; molecular clusters; cyanuric acid; self-assembly; symmetry. ... Chemical Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai 600 020, India; Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, USA; Indian Institute of Science Education and ...

  17. Kainic acid and 1'-hydroxykainic acid from Palmariales.

    Science.gov (United States)

    Ramsey, U P; Bird, C J; Shacklock, P F; Laycock, M V; Wright, J L

    1994-01-01

    The distribution of kainic acid among various red algae was investigated. Analysis of free amino acids from different populations of Palmaria palmata showed that some were unable to accumulate kainic acid to detectable concentrations, whereas in two dwarf mutants it was a major component of the free amino acid composition. The amino acid profiles were also examined for unknown amino acids in the search for possible intermediates in kainic acid biosynthesis. The only unknown amino acid present in P. palmata extracts was isolated and identified by NMR spectroscopy as 1'-hydroxykainic acid. This compound was found in all samples that contained kainic acid. To investigate the effect of growth conditions on kainic acid production different strains of P. palmata were grown at 5, 10, and 15 degrees C with or without added nitrate. No effect on production was observed, suggesting that the growth conditions in these experiments do not affect the level of gene expression in the pathway of kainic acid biosynthesis. Furthermore, changing the growth conditions did not induce synthesis of kainic acid in the non-producing strains of Palmariales.

  18. 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.

  19. Progress in engineering acid stress resistance of lactic acid bacteria.

    Science.gov (United States)

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2014-02-01

    Lactic acid bacteria (LAB) are widely used for the production of a variety of fermented foods, and are considered as probiotic due to their health-promoting effect. However, LAB encounter various environmental stresses both in industrial fermentation and application, among which acid stress is one of the most important survival challenges. Improving the acid stress resistance may contribute to the application and function of probiotic action to the host. Recently, the advent of genomics, functional genomics and high-throughput technologies have allowed for the understanding of acid tolerance mechanisms at a systems level, and many method to improve acid tolerance have been developed. This review describes the current progress in engineering acid stress resistance of LAB. Special emphasis is placed on engineering cellular microenvironment (engineering amino acid metabolism, introduction of exogenous biosynthetic capacity, and overproduction of stress response proteins) and maintaining cell membrane functionality. Moreover, strategies to improve acid tolerance and the related physiological mechanisms are also discussed.

  20. Adipic acid tolerance screening for potential adipic acid production hosts.

    Science.gov (United States)

    Karlsson, Emma; Mapelli, Valeria; Olsson, Lisbeth

    2017-02-01

    Biobased processes for the production of adipic acid are of great interest to replace the current environmentally detrimental petrochemical production route. No efficient natural producer of adipic acid has yet been identified, but several approaches for pathway engineering have been established. Research has demonstrated that the microbial production of adipic acid is possible, but the yields and titres achieved so far are inadequate for commercialisation. A plausible explanation may be intolerance to adipic acid. Therefore, in this study, selected microorganisms, including yeasts, filamentous fungi and bacteria, typically used in microbial cell factories were considered to evaluate their tolerance to adipic acid. Screening of yeasts and bacteria for tolerance to adipic acid was performed in microtitre plates, and in agar plates for A. niger in the presence of adipic acid over a broad range of concentration (0-684 mM). As the different dissociation state(s) of adipic acid may influence cells differently, cultivations were performed with at least two pH values. Yeasts and A. niger were found to tolerate substantially higher concentrations of adipic acid than bacteria, and were less affected by the undissociated form of adipic acid than bacteria. The yeast exhibiting the highest tolerance to adipic acid was Candida viswanathii, showing a reduction in maximum specific growth rate of no more than 10-15% at the highest concentration of adipic acid tested and the tolerance was not dependent on the dissociation state of the adipic acid. Tolerance to adipic acid was found to be substantially higher among yeasts and A. niger than bacteria. The explanation of the differences in adipic acid tolerance between the microorganisms investigated are likely related to fundamental differences in their physiology and metabolism. Among the yeasts investigated, C. viswanathii showed the highest tolerance and could be a potential host for a future microbial cell factory for adipic acid.

  1. Boswellic acid inhibits expression of acid sphingomyelinase in intestinal cells

    Directory of Open Access Journals (Sweden)

    Duan Rui-Dong

    2009-12-01

    Full Text Available Abstract Background Boswellic acid is a type of triterpenoids with antiinflammatory and antiproliferative properties. Sphingomyelin metabolism generates multiple lipid signals affecting cell proliferation, inflammation, and apoptosis. Upregulation of acid sphingomyelinase (SMase has been found in several inflammation-related diseases such as inflammatory bowel diseases, atherosclerosis, and diabetes. Methods The present study is to examine the effect of 3-acetyl-11-keto-β-boswellic acids (AKBA, a potent boswellic acid, on acid SMase activity and expression in intestinal cells. Both transformed Caco-2 cells and non-transformed Int407 cells were incubated with AKBA. After incubation, the change of acid SMase activity was assayed biochemically, the enzyme protein was examined by Western blot, and acid SMase mRNA was quantified by qPCR. Results We found that AKBA decreased acid SMase activity in both intestinal cell lines in dose and time dependent manners without affecting the secretion of the enzyme to the cell culture medium. The effect of AKBA was more effective in the fetal bovine serum-free culture medium. Among different types of boswellic acid, AKBA was the most potent one. The inhibitory effect on acid SMase activity occurred only in the intact cells but not in cell-free extract in the test tubes. At low concentration, AKBA only decreased the acid SMase activity but not the quantity of the enzyme protein. However, at high concentration, AKBA decreased both the mass of acid SMase protein and the mRNA levels of acid SMase in the cells, as demonstrated by Western blot and qPCR, respectively. Under the concentrations decreasing acid SMase activity, AKBA significantly inhibited cell proliferation. Conclusion We identified a novel inhibitory effect of boswellic acids on acid SMase expression, which may have implications in human diseases and health.

  2. Selective hydrodeoxygenation of tartaric acid to succinic acid

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiayi [Department of Chemical and Biomolecular Engineering; University of Delaware; Newark; USA; Catalysis Center for Energy Innovation; Vasiliadou, Efterpi S. [Catalysis Center for Energy Innovation; University of Delaware; Newark; USA; Goulas, Konstantinos A. [Catalysis Center for Energy Innovation; University of Delaware; Newark; USA; Saha, Basudeb [Catalysis Center for Energy Innovation; University of Delaware; Newark; USA; Vlachos, Dionisios G. [Department of Chemical and Biomolecular Engineering; University of Delaware; Newark; USA; Catalysis Center for Energy Innovation

    2017-01-01

    A novel one-step process for the selective production of succinic acid from tartaric acid is developed. High succinic yield is achieved in an efficient catalytic system comprised of MoOx/BC, HBr and acetic acid under hydrogen atmosphere.

  3. Formic acid assisted hydrogenation of levulinic acid to ...

    Indian Academy of Sciences (India)

    Muppala Ashokraju

    2018-02-07

    Feb 7, 2018 ... formic acid) as it is obtained through the hydrolysis of biomass that contains water. In this context, we have per- formed the hydrogenation of levulinic acid with formic acid in presence of water (LA: FA: H2O 1:5:1) and the results are displayed in Figure 7b. The results indicate better performance of the cat-.

  4. 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

  5. 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 ...

  6. (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.

  7. Acid hydrolysis of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, H.

    1980-12-01

    One of the alternatives to increase world production of etha nol is by the hydrolysis of cellulose content of agricultural residues. Studies have been made on the types of hydrolysis: enzimatic and acid. Data obtained from the sulphuric acid hydrolysis of cellulose showed that this process proceed in two steps, with a yield of approximately 95% glucose. Because of increases in cost of alternatives resources, the high demand of the product and the more economic production of ethanol from cellulose materials, it is certain that this technology will be implemented in the future. At the same time further studies on the disposal and reuse of the by-products of this production must be undertaken.

  8. 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....

  9. 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. ...

  10. Electrochemistry of nucleic acids

    Czech Academy of Sciences Publication Activity Database

    Paleček, Emil; Bartošík, Martin

    2012-01-01

    Roč. 112, č. 6 (2012), s. 3427-3481 ISSN 0009-2665 R&D Projects: GA ČR(CZ) GAP301/11/2055; GA MŠk(CZ) ME09038; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : nucleic acids electrochemistry * DNA biosensors * DNA damage Subject RIV: BO - Biophysics Impact factor: 41.298, year: 2012

  11. 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

  12. 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 ...

  13. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    OpenAIRE

    NEENA GARG

    2015-01-01

    Lactic acid bacteria (LAB) is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LA...

  14. Levulinic acid in organic synthesis

    International Nuclear Information System (INIS)

    Timokhin, Boris V; Baransky, V A; Eliseeva, G D

    1999-01-01

    Data concerning the methods of synthesis, chemical transformations and application of levulinic acid are analysed and generalised. The wide synthetic potential of levulinic acid, particularly as a key compound in the synthesis of various heterocyclic systems, saturated and unsaturated ketones and diketones, difficultly accessible acids and other compounds is demonstrated. The accessibility of levulinic acid from hexose-containing wood-processing and agricultural wastes is noted. The bibliography includes 260 references.

  15. 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.

  16. Macrocyclic polyether complexes of amino acids and amino acid salts

    International Nuclear Information System (INIS)

    Bidzilya, V.A.; Oleksenko, LP.

    1985-01-01

    This paper deals with the isolation of the complexes formed between various types of amino acid derivatives and macrocyclic polyethers, and the characterisation of their physical and chemical properties. The study shows that macrocyclic polyethers form 1:1 complexes with amino acids and amino acid derivatives, and that these complexes can be isolated in pure form. Amino acids can be bound to these complexes in their anionic forms, in switterionic forms, as well as in their protonated forms. These types of complexes may be useful for the transport of amino acids or their derivatives across both synthetic and natural membranes

  17. 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.

  18. 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...

  19. 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.

  20. 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

  1. 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)

  2. Acidic aerosol in urban air

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, M.; Yamaoka, S.; Miyazaki, T.; Oka, M.

    1982-01-01

    The distribution and chemical composition of acidic aerosol in Osaka City were investigated. Samples were collected at five sites in the city from June to September, 1979. Acidic aerosol was determined by the acid-base titration method, sulfate ion by barium chloride turbidimetry, nitrate ion by the xylenol method, and chloride ion by the mercury thiocyanate method. The concentration of acidic aerosol at five sites ranged from 7.7 micrograms per cubic meter to 10.0 micrograms per cubic meter, but mean concentrations in the residential area were slightly higher than those in the industrial area. When acidic aerosol concentrations were compared with concentrations of sulfate, nitrate, and chloride ions, a significant correlation was found between acidic aerosol and sulfate ion. The sum of the ion equivalents of the three types showed good correlation with the acidic aerosol equivalent during the whole period.

  3. Adsorption of humic acid on acid-activated Greek bentonite.

    Science.gov (United States)

    Doulia, Danae; Leodopoulos, Ch; Gimouhopoulos, K; Rigas, F

    2009-12-15

    The adsorption of humic acid on bentonite from Milos Island (Greece) acid-treated with dilute H(2)SO(4) solutions over a concentration range between 0.25 and 13M has been studied. Bentonite activated with 3M sulfuric acid (AAS) showed a higher efficiency in removing humic acid from aqueous solutions and was selected for further investigation. The specific surface area of acid-activated bentonite was estimated using the methylene blue adsorption method. The morphology of untreated, activated, and HA-sorbed bentonite was studied under scanning electron microscope (SEM). The effects of contact time, adsorbate concentration, adsorbent dose, and temperature on the adsorption of humic acid onto bentonite activated with 3M H(2)SO(4) were studied using a batch adsorption technique. Acidic pH and high ionic strength proved to be favorable for the adsorption efficiency. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to describe the kinetic data and the rate constants were evaluated. The experimental isotherm data were analyzed using Langmuir, Freundlich, and Temkin equations and the isotherm constants were determined. Thermodynamic parameters (DeltaH(o), DeltaS(o), and DeltaG(o)) of adsorption of humic acid onto acid-activated bentonite with 3M sulfuric acid were also evaluated.

  4. Cytenamide acetic acid solvate

    OpenAIRE

    Johnston, Andrea; Florence, Alastair J.; Fabianni, Francesca J. A.; Shankland, Kenneth; Bedford, Colin T.

    2008-01-01

    In the crystal structure of the title compound (systematic name: 5H-dibenzo[a,d]cycloheptatriene-5-carboxamide ethanoic acid solvate), C16H13NO C2H4O2, the cytenamide and solvent molecules form a hydrogen-bonded R2 2(8) dimer motif, which is further connected to form a centrosymmetric double ring motif arrangement. The cycloheptene ring adopts a boat conformation and the dihedral angle between the leastsquares planes through the two aromatic rings is 54.7 (2) . peer...

  5. Crassulacean acid metabolism

    Directory of Open Access Journals (Sweden)

    Thomas David Geydan

    2005-07-01

    Full Text Available A review of Crassulacean acid metabolism is presented, characterized by showing the occurrence, activity and plasticity of these complex mechanism at the physiological, biochemical and molecular level, framed by the presence of the denominated four phases in CAM and its repercussion and expression due to different stresses in an ecological context. The basic enzymes, and metabolites necessary for the optional functioning of CAM are presented as well as their mode of action and cellular control. Finally, it is shown how environmental conditions and molecular signalling mediate the phenotypic plasticity.

  6. 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.

  7. Simultaneous liquid-chromatographic quantitation of salicylic acid, salicyluric acid, and gentisic acid in urine.

    Science.gov (United States)

    Cham, B E; Bochner, F; Imhoff, D M; Johns, D; Rowland, M

    1980-01-01

    We have developed a specific and sensitive method for the determination of salicylic acid, salicyluric acid, and gentisic acid in urine. Any proteins present are precipitated with methyl cyanide. After centrifugation, an aliquot of the supernate is directly injected into an octadecyl silane reversed-phase chromatographic column, then eluted with a mixture of water, butanol, acetic acid, and sodium sulfate, and quantitated at 313 nm by ultraviolet detection according to peak-height ratios (with internal standard, o-methoxybenzoic acid) or peak heights (no internal standard). The method allows estimates within 25 min. Sensitivity was 0.2 mg/L for gentisic acid, and 0.5 mg/L for both salicyluric and salicylic acid (20-micro L injection volume); response was linear with concentration to at least 2.000 g/L for salicylic acid and metabolites. Analytical recovery of salicylic acid and metabolites from urine is complete. Intra-assay precision (coefficient of variation) is 5.52% at 7.5 mg/L for salicylic acid, 5.01% at 9.33 mg/L for salicyluric acid, and 3.07% at 7.96 mg/L for gentisic acid. Interassay precision is 7.32% at 7.51 mg/L for salicylic acid, 5.52% at 8.58 mg/L for salicyluric acid, and 3.97% at 8.32 mg/L for gentisic acid. We saw no significant interference in urine from patients being treated with various drugs other than aspirin.

  8. 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

  9. 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.

  10. 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

  11. Production of boron carbide powder by carbothermal synthesis of ...

    Indian Academy of Sciences (India)

    Boron carbide (B4C) powder has been produced by carbothermal reduction of boric acid–citric acid gel. Initially a gel of boric acid–citric acid is prepared in an oven at 100°C. This gel is pyrolyzed in a high temperature furnace over a temperature range of 1000–1800°C. The reaction initiation temperature range for B4C ...

  12. Vibrational structure of the polyunsaturated fatty acids eicosapentaenoic acid and arachidonic acid studied by infrared spectroscopy

    Science.gov (United States)

    Kiefer, Johannes; Noack, Kristina; Bartelmess, Juergen; Walter, Christian; Dörnenburg, Heike; Leipertz, Alfred

    2010-02-01

    The spectroscopic discrimination of the two structurally similar polyunsaturated C 20 fatty acids (PUFAs) 5,8,11,14,17-eicosapentaenoic acid and 5,8,11,14-eicosatetraenoic acid (arachidonic acid) is shown. For this purpose their vibrational structures are studied by means of attenuated total reflection (ATR) Fourier-transform infrared (FT-IR) spectroscopy. The fingerprint regions of the recorded spectra are found to be almost identical, while the C-H stretching mode regions around 3000 cm -1 show such significant differences as results of electronic and molecular structure alterations based on the different degree of saturation that both fatty acids can be clearly distinguished from each other.

  13. 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, and 1.2 microM, respectively, in a functional GluR5 assay. Compound 6c (IC(50) = 4.8 microM at GluR5) showed activity in the in vivo ATPA rigidity test, indicating that 6c has better pharmacokinetic properties than 8h, which was inactive in this test. The AUBAs are the first example of a series...

  14. 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

  15. Maleic acid and succinic acid in fermented alcoholic beverages are the stimulants of gastric acid secretion.

    Science.gov (United States)

    Teyssen, S; González-Calero, G; Schimiczek, M; Singer, M V

    1999-03-01

    Alcoholic beverages produced by fermentation (e.g., beer and wine) are powerful stimulants of gastric acid output and gastrin release in humans. The aim of this study was to separate and specify the gastric acid stimulatory ingredients in alcoholic beverages produced by fermentation. Yeast-fermented glucose was used as a simple model of fermented alcoholic beverages; it was stepwise separated by different methods of liquid chromatography, and each separated solution was tested in human volunteers for its stimulatory action on gastric acid output and gastrin release. Five substances were detected by high-performance liquid chromatography and were analyzed by mass spectrometry and 1H-13C nuclear magnetic resonance spectroscopy. At the end of the separation process of the five identified substances, only the two dicarboxylic acids, maleic acid and succinic acid, had a significant (P fermented glucose, respectively), but not on gastrin release. When given together, they increased gastric acid output by 100% of fermented glucose and by 95% of maximal acid output. We therefore conclude that maleic acid and succinic acid are the powerful stimulants of gastric acid output in fermented glucose and alcoholic beverages produced by fermentation, and that gastrin is not their mediator of action.

  16. Effect of baseline plasma fatty acids on eicosapentaenoic acid levels in individuals supplemented with alpha-linolenic acid.

    Science.gov (United States)

    DeFilippis, Andrew P; Harper, Charles R; Cotsonis, George A; Jacobson, Terry A

    2009-01-01

    We previously reported a >50% increase in mean plasma eicosapentaenoic acid levels in a general medicine clinic population after supplementation with alpha-linolenic acid. In the current analysis, we evaluate the variability of changes in eicosapentaenoic acid levels among individuals supplemented with alpha-linolenic acid and evaluated the impact of baseline plasma fatty acids levels on changes in eicosapentaenoic acid levels in these individuals. Changes in eicosapentaenoic acid levels among individuals supplemented with alpha-linolenic acid ranged from a 55% decrease to a 967% increase. Baseline plasma fatty acids had no statistically significant effect on changes in eicosapentaenoic levels acid after alpha-linolenic acid supplementation. Changes in eicosapentaenoic acid levels varied considerably in a general internal medicine clinic population supplemented with alpha-linolenic acid. Factors that may impact changes in plasma eicosapentaenoic acid levels after alpha-linolenic acid supplementation warrant further study.

  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. Dissociation of weak acids during Gran plot free acidity titrations

    OpenAIRE

    Lindberg, Steven E:; Cole, Jan M.

    2011-01-01

    A comparison of weak and free acid concentrations measured by base titration and hydrogen ionactivities determined by direct pH measurement is described for several of our data sets for raincollected above and below a forest canopy in the eastern United States. These data illustrate theinfluence of weak acid dissociation during titration and the possible effect of activity coefficientson calculated free acid concentrations.DOI: 10.1111/j.1600-0889.1984.tb00240.x

  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. Adipic acid tolerance screening for potential adipic acid production hosts

    OpenAIRE

    Karlsson, Emma; Mapelli, Valeria; Olsson, Lisbeth

    2017-01-01

    Background Biobased processes for the production of adipic acid are of great interest to replace the current environmentally detrimental petrochemical production route. No efficient natural producer of adipic acid has yet been identified, but several approaches for pathway engineering have been established. Research has demonstrated that the microbial production of adipic acid is possible, but the yields and titres achieved so far are inadequate for commercialisation. A plausible explanation ...

  1. 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)

  2. 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)

  3. Phytanic acid metabolism in health and disease

    NARCIS (Netherlands)

    Wanders, Ronald J. A.; Komen, Jasper; Ferdinandusse, Sacha

    2011-01-01

    Phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) is a branched-chain fatty acid which cannot be beta-oxidized due to the presence of the first methyl group at the 3-position. Instead, phytanic acid undergoes alpha-oxidation to produce pristanic acid (2,6,10,14-tetramethylpentadecanoic acid)

  4. 49 CFR 173.158 - Nitric acid.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Nitric acid. 173.158 Section 173.158... Nitric acid. (a) Nitric acid exceeding 40 percent concentration may not be packaged with any other material. (b) Nitric acid in any concentration which does not contain sulfuric acid or hydrochloric acid as...

  5. 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)

  6. 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.

  7. 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......,4-lactone, respectively. A 2,3-aziridino-2,3-dideoxypentonamide 70 was also prepared from D-glucono-1,5-lactone. The lactones were converted into methyl 3,4-O-isopropylidene-2-O-sulfonyl esters 42, 50, 62 and 68, which upon treatment with concentrated aqueous ammonia yielded the aziridino compounds...... 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...

  8. 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

  9. 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)

  10. Antibiofilm Properties of Acetic Acid

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup

    2014-01-01

    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....

  11. 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....

  12. Kinetics of oxidation of acidic amino acids by sodium N ...

    Indian Academy of Sciences (India)

    Unknown

    ... the mechanism of amino acids metabolism. Amino acids find a number of applications in biochemical research, metabolism, microbiology, nutrition, pharmaceuticals and fortification of foods and feeds. Generally only the amino and carboxyl functional groups in RCH(NH2)COOH undergo chemical transformations while.

  13. 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

  14. Lipoic acid and diabetes: Effect of dihydrolipoic acid administration ...

    Indian Academy of Sciences (India)

    Relative α-lipoic acid content of diabetic livers was considerably less than that of normal livers as determined by gas chromatography. It was not possible to detect any dihydrolipoic acid in the livers. Biochemical abnormalities such as hyperglycaemia, ketonemia, reduction in liver glycogen and impaired incorporation of ...

  15. Amino acids analysis during lactic acid fermentation by single strain ...

    African Journals Online (AJOL)

    SAM

    2014-07-09

    Jul 9, 2014 ... Amino acids analysis during lactic acid fermentation by single strain cultures of lactobacilli and mixed culture starter made from them. KiBeom Lee1*, Ho-Jin Kim1 and Sang-Kyu Park2. 1Bio Center Technopark, 7-50 Songdo, Yeonsu-Gu, Incheon 406-840, Republic of Korea. 2Nambu University, Chumdan ...

  16. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances

    Directory of Open Access Journals (Sweden)

    Je Min Lee

    2016-01-01

    Full Text Available Polyunsaturated fatty acids (PUFAs are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism.

  17. 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 ...

  18. 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

  19. Neuroexcitatory amino acids: 4-methylene glutamic acid derivatives : Short Communication.

    Science.gov (United States)

    Receveur, J M; Roumestant, M L; Viallefont, P

    1995-12-01

    A short synthesis of 4-methylene glutamic acid was achieved. Under thermal conditions the corresponding anhydride reacted with 2,3 dimethylbutadiene to afford the corresponding DIELS-ALDER adduct in good yield. L-4-methylene glutamic acid essentially acts on glutamate metabotropic receptors and is as potent as L-Glu in producing IPs.

  20. Nucleic Acid Backbone Structure Variations: Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    Nielsen, Peter E.

    2010-01-01

    Synthetic analogues and mimics of the natural genetic material deoxyribonucleic acid (DNA) are potential gene therapeutic (antisense or antigene) drugs. One of these mimics, peptide nucleic acids (PNAs), are chemically closer to peptides and proteins than to DNA, but nonetheless have retained many...

  1. 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.

  2. Formic acid assisted hydrogenation of levulinic acid to γ ...

    Indian Academy of Sciences (India)

    Vapor phase hydrogenation of levulinic acid using formic acid as a hydrogen source has been conducted over ordered mesoporous Cu/Fe2O3 catalysts prepared by hard template method using mesoporous silica, SBA-15. X-ray diffraction result reveals the absence of copper peaks because of either highly dispersed state, ...

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

    Indian Academy of Sciences (India)

    IAS Admin

    organic chemistry' and of the theoretical treatment of the chemical bond, essential to an understanding of how natural products are formed through biosynthetic processes (enzyme mediated synthe- sis of complex structures from substrates of primary structure). C-11 and C-12 Acids. Oxidation of abietic acid or its methyl ...

  4. Mechanisms and improvement of acid resistance in lactic acid bacteria.

    Science.gov (United States)

    Wang, Chao; Cui, Yanhua; Qu, Xiaojun

    2018-03-01

    Lactic acid bacteria (LAB) can take advantage of fermentable carbohydrates to produce lactic acid. They are proverbially applied in industry, agricultural production, animal husbandry, food enterprise, pharmaceutical engineering and some other important fields, which are closely related to human life. For performing the probiotic functions, LAB have to face the low pH environment of the gastrointestinal tract. Therefore, acid resistance of LAB is of great importance not only for their own growth, but also for fermentation and preparation of probiotic products. Recent research studies on acid resistance mechanisms of LAB are mainly focused on neutralization process, biofilm and cell density, proton pump, protection of macromolecules, pre-adaptation and cross-protection, and effect of solutes. In this context, biotechnological strategies such as synthetic biology, genome shuffling, high pressure homogenization and adaptive laboratory evolution were also used to improve the acid resistance of LAB to respond to constantly changing low pH environment.

  5. Carbonic Acid Pretreatment of Biomass

    Energy Technology Data Exchange (ETDEWEB)

    G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry

    2003-05-31

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic

  6. Infrared spectra of hydrogen-bonded salicylic acid and its derivatives : Salicylic acid and acetylsalicylic acid

    Science.gov (United States)

    Wójcik, Marek J.

    1981-11-01

    Infrared spectra of hydrogen-bonded salicylic acid, O-deutero-salicylic acid and acetylsalicylic acid crystals have been studied experimentally and theoretically. Interpretation of these spectra was based on the Witkowski-Maréchal model. Semi-quantitative agreement between experimental and theoretical spectra can be achieved with the simplest form of this model, with values of interaction parameters transferable for equivalent intermolecular hydrogen bonds.

  7. 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

  8. 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....

  9. 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

  10. 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 ...

  11. 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.…

  12. 78 FR 20029 - Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance...

    Science.gov (United States)

    2013-04-03

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 180 [EPA-HQ-OPP-2013-0057; FRL-9381-2] Castor Oil... from the requirement of a tolerance for residues of castor oil, polymer with adipic acid, linoleic acid... eliminates the need to establish a maximum permissible level for residues of castor oil, polymer with adipic...

  13. 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.

  14. 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.)

  15. 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.

  16. Uric acid and evolution.

    Science.gov (United States)

    Álvarez-Lario, Bonifacio; Macarrón-Vicente, Jesús

    2010-11-01

    Uric acid (UA) is the end product of purine metabolism in humans due to the loss of uricase activity by various mutations of its gene during the Miocene epoch, which led to humans having higher UA levels than other mammals. Furthermore, 90% of UA filtered by the kidneys is reabsorbed, instead of being excreted. These facts suggest that evolution and physiology have not treated UA as a harmful waste product, but as something beneficial that has to be kept. This has led various researchers to think about the possible evolutionary advantages of the loss of uricase and the subsequent increase in UA levels. It has been argued that due to the powerful antioxidant activity of UA, the evolutionary benefit could be the increased life expectancy of hominids. For other authors, the loss of uricase and the increase in UA could be a mechanism to maintain blood pressure in times of very low salt ingestion. The oldest hypothesis associates the increase in UA with higher intelligence in humans. Finally, UA has protective effects against several neurodegenerative diseases, suggesting it could have interesting actions on neuronal development and function. These hypotheses are discussed from an evolutionary perspective and their clinical significance. UA has some obvious harmful effects, and some, not so well-known, beneficial effects as an antioxidant and neuroprotector.

  17. Phosphonic acid: preparation and applications

    Directory of Open Access Journals (Sweden)

    Charlotte M. Sevrain

    2017-10-01

    Full Text Available The phosphonic acid functional group, which is characterized by a phosphorus atom bonded to three oxygen atoms (two hydroxy groups and one P=O double bond and one carbon atom, is employed for many applications due to its structural analogy with the phosphate moiety or to its coordination or supramolecular properties. Phosphonic acids were used for their bioactive properties (drug, pro-drug, for bone targeting, for the design of supramolecular or hybrid materials, for the functionalization of surfaces, for analytical purposes, for medical imaging or as phosphoantigen. These applications are covering a large panel of research fields including chemistry, biology and physics thus making the synthesis of phosphonic acids a determinant question for numerous research projects. This review gives, first, an overview of the different fields of application of phosphonic acids that are illustrated with studies mainly selected over the last 20 years. Further, this review reports the different methods that can be used for the synthesis of phosphonic acids from dialkyl or diaryl phosphonate, from dichlorophosphine or dichlorophosphine oxide, from phosphonodiamide, or by oxidation of phosphinic acid. Direct methods that make use of phosphorous acid (H3PO3 and that produce a phosphonic acid functional group simultaneously to the formation of the P–C bond, are also surveyed. Among all these methods, the dealkylation of dialkyl phosphonates under either acidic conditions (HCl or using the McKenna procedure (a two-step reaction that makes use of bromotrimethylsilane followed by methanolysis constitute the best methods to prepare phosphonic acids.

  18. Studies on biphenyl disulphonic acid doped polyanilines: Synthesis ...

    Indian Academy of Sciences (India)

    zed protonic acids, such as camphorsulfonic acid, dodecyl- benzene sulfonic acid, para-toluene sulfonic acid, benzene sulfonic acid, sulfanilic acid, sulfamic acid, octyl-benzene sulfonic acid, sulfosalicylic acid or methane sulfonic acid as dopants (Epstein et al 1987; Li et al 1987; Dhawan and Trivedi 1991, 1992; Kobayashi ...

  19. Expression of sialic acids and other nonulosonic acids in Leptospira

    Directory of Open Access Journals (Sweden)

    Ricaldi N Jessica

    2012-08-01

    Full Text Available Abstract Background Sialic acids are negatively charged nine carbon backbone sugars expressed on mammalian cell surfaces. Sialic acids are part of a larger family of nonulosonic acid (NulO molecules that includes pseudaminic and legionaminic acids. Microbial expression of sialic acids and other nonulosonic acids has been shown to contribute to host-microbe interactions in a variety of contexts, including participation in colonization, immune subversion, and behaviors such as biofilm formation, autoagglutination and motility. Previous research has suggested that some spirochetes may also express these molecules. Results Here we use a combination of molecular tools to investigate the presence of NulO biosynthetic gene clusters among clinical and saprophytic isolates of the genus Leptospira. Polymerase chain reaction and Southern blotting suggested that a variety of leptospires encoded NulO biosynthetic pathways. High performance liquid chromatography and mass spectrometry analyses provided biochemical evidence that di-N-acetylated NulO molecules are expressed at relatively high levels by L. interrogans serovar Lai strain 55601, and at lower levels by L. alexanderi serovar Manhao and L. fainei serovar Hurstbridge. Endogenous expression of N-acetylneuraminic acid (Neu5Ac, the most common sialic acid was documented in L. interrogans serovar Copenhageni strain L1-130. Neu5Ac biosynthesis is also supported by a unique gene fusion event resulting in an enzyme with an N-terminal N-acetylneuraminic acid synthase domain and a C-terminal phosphatase domain. This gene fusion suggests that L. interrogans uses a Neu5Ac biosynthetic pathway more similar to animals than to other bacteria. Analysis of the composition and phylogeny of putative NulO biosynthetic gene clusters in L. interrogans serovar Lai and serovar Copenhageni revealed that both strains have complete biosynthetic pathways for legionamimic acid synthesis, a molecule with the same stereochemistry

  20. 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)

  1. 21 CFR 184.1007 - Aconitic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aconitic acid. 184.1007 Section 184.1007 Food and... Substances Affirmed as GRAS § 184.1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid... Ranunculaceae. Transaconitic acid can be isolated during sugarcane processing, by precipitation as the calcium...

  2. Amino Acid Catabolism in Plants.

    Science.gov (United States)

    Hildebrandt, Tatjana M; Nunes Nesi, Adriano; Araújo, Wagner L; Braun, Hans-Peter

    2015-11-02

    Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signaling processes as well as in plant stress response. In general, pool sizes of the 20 amino acids differ strongly and change dynamically depending on the developmental and physiological state of the plant cell. Besides amino acid biosynthesis, which has already been investigated in great detail, the catabolism of amino acids is of central importance for adjusting their pool sizes but so far has drawn much less attention. The degradation of amino acids can also contribute substantially to the energy state of plant cells under certain physiological conditions, e.g. carbon starvation. In this review, we discuss the biological role of amino acid catabolism and summarize current knowledge on amino acid degradation pathways and their regulation in the context of plant cell physiology. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  3. Diabetes and alpha lipoic acid

    Directory of Open Access Journals (Sweden)

    Issy eLaher

    2011-11-01

    Full Text Available Diabetes mellitus is a multi-faceted metabolic disorder where there is increased oxidative stress that contributes to the pathogenesis of this debilitating disease. This has prompted several investigations into the use of antioxidants as a complementary therapeutic approach. Alpha lipoic acid, a naturally occurring dithiol compound which plays an essential role in mitochondrial bioenergetic reactions, has gained considerable attention as an antioxidant for use in managing diabetic complications. Lipoic acid quenches reactive oxygen species, chelates metal ions, and reduces the oxidized forms of other antioxidants such as vitamin C, vitamin E and glutathione. It also boosts antioxidant defense system through Nrf2-mediated antioxidant gene expression and by modulation of peroxisome proliferator activated receptors-regulated genes. ALA inhibits nuclear factor kappa B and activates AMPK in skeletal muscles, which in turn have a plethora of metabolic consequences. These diverse actions suggest that a lipoic acid acts by multiple mechanisms, many of which have only been uncovered recently. In this review we briefly summarize the known biochemical properties of lipoic acid and then discussed the oxidative mechanisms implicated in diabetic complications and the mechanisms by which lipoic acid may ameliorate these reactions. The findings of some of the clinical trials in which lipoic acid administration has been tested in diabetic patients during the last 10 years are summarized. It appears that the clearest benefit of lipoic acid supplementation is in patients with diabetic neuropathy.

  4. Renal handling of terephthalic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tremaine, L.M.; Quebbemann, A.J.

    1985-01-01

    By use of the Sperber in vivo chicken preparation method, infusion of radiolabeled terephthalic acid ((/sup 14/C)TPA) into the renal portal circulation revealed a first-pass excretion of the unchanged compound into the urine. This model was utilized further to characterize the excretory transport of (/sup 14/C)TPA and provide information on the structural specificity in the secretion of dicarboxylic acids. At an infusion rate of 0.4 nmol/min. 60% of the (/sup 14/C)TPA which reached the kidney was directly excreted. An infusion rate of 3 or 6 mumol/min resulted in complete removal of (/sup 14/C)TPA by the kidney. These results indicate that TPA is both actively secreted and actively reabsorbed when infused at 0.4 nmol/min and that active reabsorption is saturated with the infusion of TPA at higher concentrations. The secretory process was saturated with the infusion of TPA at 40 mumol/mn. The excretory transport of TPA was inhibited by the infusion of probenecid, salicylate, and m-hydroxybenzoic acid, indicating that these organic acids share the same organic anion excretory transport process. m-Hydroxybenzoic acid did not alter the simultaneously measured excretory transport of p-aminohippuric acid (PAH), suggesting that there are different systems involved in the secretion of TPA and PAH. The structural specificity for renal secretion of dicarboxylic acids was revealed by the use of o-phthalic acid and m-phthalic acid as possible inhibitors of TPA secretion.

  5. Milk fatty acid composition and conjugated linoleic acid content of ...

    African Journals Online (AJOL)

    2015-10-20

    Oct 20, 2015 ... ISSN 0375-1589 (print), ISSN 2221-4062 (online). Publisher: South African Society for Animal Science http://dx.doi.org/10.4314/sajas.v45i4.7. Milk fatty acid composition and conjugated linoleic acid content of Jersey and. Fleckvieh x Jersey cows in a pasture-based feeding system. B. Sasanti1,2, S. Abel2, ...

  6. 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.

  7. 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

  8. 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.

  9. Enhanced acid tolerance of Rhizopus oryzae during fumaric acid production.

    Science.gov (United States)

    Liu, Ying; Lv, Chunwei; Xu, Qing; Li, Shuang; Huang, He; Ouyang, Pingkai

    2015-02-01

    Ensuring a suitable pH in the culture broth is a major problem in microorganism-assisted industrial fermentation of organic acids. To address this issue, we investigated the physiological changes in Rhizopus oryzae at different extracellular pH levels and attempted to solve the issue of cell shortage under low pH conditions. We compared various parameters, such as membrane fatty acids' composition, intracellular pH, and adenosine triphosphate (ATP) concentration. It was found that the shortage of intracellular ATP might be the main reason for the low rate of fumaric acid production by R. oryzae under low pH conditions. When 1 g/l citrate was added to the culture medium at pH 3.0, the intracellular ATP concentration increased from 0.4 to 0.7 µmol/mg, and the fumaric acid titer was enhanced by 63% compared with the control (pH 3.0 without citrate addition). The final fumaric acid concentration at pH 3.0 reached 21.9 g/l after 96 h of fermentation. This strategy is simple and feasible for industrial fumaric acid production under low pH conditions.

  10. Hydroxy, carboxylic and amino acid functionalized ...

    Indian Academy of Sciences (India)

    precipitation method and modified with different coating agents such as ascorbic acid, hexanoic acid, salicylic acid, L-arginine and L-cysteine. The synthesized nanoparticles were characterized by various techniques such as FT IR, XRD, VSM, ...

  11. Molar extinction coefficients of some fatty acids

    DEFF Research Database (Denmark)

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

    2002-01-01

    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......) 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...

  12. 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.)

  13. Humic acid protein complexation

    Science.gov (United States)

    Tan, W. F.; Koopal, L. K.; Weng, L. P.; van Riemsdijk, W. H.; Norde, W.

    2008-04-01

    Interactions of purified Aldrich humic acid (PAHA) with lysozyme (LSZ) are investigated. In solution LSZ is moderately positively and PAHA negatively charged at the investigated pH values. The proton binding of PAHA and of LSZ is determined by potentiometric proton titrations at various KCl concentrations. It is also measured for two mixtures of PAHA-LSZ and compared with theoretically calculated proton binding assuming no mutual interaction. The charge adaptation due to PAHA-LSZ interaction is relatively small and only significant at low and high pH. Next to the proton binding, the mass ratio PAHA/LSZ at the iso-electric point (IEP) of the complex at given solution conditions is measured together with the pH using the Mütek particle charge detector. From the pH changes the charge adaptation due to the interaction can be found. Also these measurements show that the net charge adaptation is weak for PAHA-LSZ complexes at their IEP. PAHA/LSZ mass ratios in the complexes at the IEP are measured at pH 5 and 7. At pH 5 and 50 mmol/L KCl the charge of the complex is compensated for 30-40% by K +; at pH 7, where LSZ has a rather low positive charge, this is 45-55%. At pH 5 and 5 mmol/L KCl the PAHA/LSZ mass ratio at the IEP of the complex depends on the order of addition. When LSZ is added to PAHA about 25% K + is included in the complex, but no K + is incorporated when PAHA is added to LSZ. The flocculation behavior of the complexes is also different. After LSZ addition to PAHA slow precipitation occurs (6-24 h) in the IEP, but after addition of PAHA to LSZ no precipitation can be seen after 12 h. Clearly, PAHA/LSZ complexation and the colloidal stability of PAHA-LSZ aggregates depend on the order of addition. Some implications of the observed behavior are discussed.

  14. 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

  15. 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...

  16. 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...

  17. 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)

  18. 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

  19. 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 ...

  20. 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.

  1. Main: Amino acid Analysis [KOME

    Lifescience Database Archive (English)

    Full Text Available Amino acid Analysis GO classification InterPro Result of GO classification by Inter...Pro motif search result kome_go_classification_interpro.zip kome_go_classification_interpro ...

  2. Main: Amino acid Analysis [KOME

    Lifescience Database Archive (English)

    Full Text Available Amino acid Analysis GO classification GenBank Result of GO classification by GenBan...k homology search result kome_go_classification_genbank.zip kome_go_classification_genbank ...

  3. 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.

  4. 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

  5. Antibiofilm Properties of Acetic Acid

    Science.gov (United States)

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup; Nielsen, Anne K.; Johansen, Helle Krogh; Homøe, Preben; Høiby, Niels; Givskov, Michael; Kirketerp-Møller, Klaus

    2015-01-01

    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 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. PMID:26155378

  6. 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.)

  7. 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.

  8. Metal complexes of phosphinic acids

    International Nuclear Information System (INIS)

    Das, P.N.M.; Kuchen, W.; Keck, H.; Haegele, G.

    1977-01-01

    Pr(III), Nd(III) and Eu(III) complexes of dimethyldithiophosphinic acid have been prepared. Their properties and structures have been studied using elemental analysis, molecular weight determination, IR, UV, mass, NMR, magnetic studies, etc. It is found that these metals form neutral complexes of the type ML 3 where L is a deprotonated bidentate dimethyldithiophosphinic acid molecule. The coordination number exhibited by these metals in this case is six. Octahedral structures have been assigned to these complexes. (author)

  9. Hydroxamic acid surface active agents

    Directory of Open Access Journals (Sweden)

    El-Sawy, A. A.

    2001-10-01

    Full Text Available p-Hydroxy phenyloctadecanol and p-hydroxy phenyloctadecanoic acid were used as new precursors for the preparation of surface active hydroxamic acid including different moles of propylene oxide. The hydroxamic acid was prepared by the reaction of propenoxylated products with sodium chloroacetate, followed by methyl esterification and the resultant product reacted with hydroxyl amine hydrochloride to give the hydroxamic acid. The structures of prepared hydroxamic acid were confirmed by spectroscopic study. The surface activity of prepared hydroxamic acid was studied; the results revealed that, the prepared hydroxamic acid has pronounced surface activity, the alcohol substrate shows a surface activity superior than the acid substrate.Se han utilizado el p-hidroxifeniloctadecanol y el ácido p-hidroxifeniloctadecanoico como nuevos precursores para la preparación de tensioactivos derivados del ácido hidroxámico, que incluyen diferentes moles de óxido de propileno. El ácido hidroxámico se preparó por reacción de los productos propenoxilados con cloroacetato sódico, seguido de la formación de ésteres metílicos, y los productos resultantes se hicieron reaccionar con clorhidrato de hidroxilamina para dar los derivados del ácido hidroxámico. Las estructuras de los derivados preparados del ácido hidroxámico, se confirmaron por técnicas espectroscópicas, estudiándose su actividad superficial cuyos resultados mostraron que dichos compuestos tenían un alto valor. La actividad superficial del sustrato alcohólico fue mayor que la del sustrato ácido.

  10. Prebiotic synthesis of carboxylic acids, amino acids and nucleic acid bases from formamide under photochemical conditions⋆

    Science.gov (United States)

    Botta, Lorenzo; Mattia Bizzarri, Bruno; Piccinino, Davide; Fornaro, Teresa; Robert Brucato, John; Saladino, Raffaele

    2017-07-01

    The photochemical transformation of formamide in the presence of a mixture of TiO2 and ZnO metal oxides as catalysts afforded a large panel of molecules of biological relevance, including carboxylic acids, amino acids and nucleic acid bases. The reaction was less effective when performed in the presence of only one mineral, highlighting the role of synergic effects between the photoactive catalysts. Taken together, these results suggest that the synthesis of chemical precursors for both the genetic and the metabolic apparatuses might have occurred in a simple environment, consisting of formamide, photoactive metal oxides and UV-radiation.

  11. Available versus digestible dietary amino acids.

    Science.gov (United States)

    Rutherfurd, Shane M; Moughan, Paul J

    2012-08-01

    Available amino acids are those absorbed from the gastrointestinal tract in a form suitable for body protein synthesis. True ileal digestible amino acids are determined based on the difference between dietary amino acid intake and unabsorbed dietary amino acids at the terminal ileum. The accuracy of ileal digestible amino acid estimates for predicting available amino acid content depends on several factors, including the accuracy of the amino acid analysis procedure. In heat processed foods, lysine can react with compounds to form nutritionally unavailable derivatives that are unstable during the hydrochloric acid hydrolysis step of amino acid analysis and can revert back to lysine causing an overestimate of available lysine. Recently, the true ileal digestible reactive (available) lysine assay based on guanidination has provided a means of accurately determining available lysine in processed foods. Methionine can be oxidised during processing to form methionine sulphoxide and methionine sulphone and cysteine oxidised to cysteic acid. Methionine sulphoxide, but not methionine sulphone or cysteic acid, is partially nutritionally available in some species of animal. Currently, methionine and cysteine are determined as methionine sulphone and cysteic acid respectively after quantitative oxidation prior to acid hydrolysis. Consequently, methionine and cysteine are overestimated if methionine sulphone or cysteic acid are present in the original material. Overall, given the problems associated with the analysis of some amino acids in processed foodstuffs, the available amino acid content may not always be accurately predicted by true ileal amino acid digestibility estimates. For such amino acids specific analytical strategies may be required.

  12. 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.

  13. Regulatory aspects of acid rain

    International Nuclear Information System (INIS)

    Dey, P.R.; Berkau, E.E.; Schnelle, K.B.

    1993-01-01

    On November 15, 1990, President Bush signed the 1990 Clean Air Act (CAA) amendments into law. This was a historical document which marked the beginning of a concerted effort to address a most pressing environmental problem of this century, namely acid rain. Acid rain is the generic term used to describe the phenomenon by which sulfur dioxides (SO 2 ) and nitrogen oxides (NO x ) react in the atmosphere in the presence of sunlight to form acids which are scrubbed out of the atmosphere during a precipitation event. When this happens the pH of the precipitation falls considerably below 7.0. Years of research have shown that acid rain has a very detrimental effect on soils, vegetation, and marine life. The large amounts of SO 2 and NO x being released by coal-fired utility boilers have largely incriminated utility companies as being the culprits. Most of the research work has been in Canada because the direction of the jet stream across the US is such that the emissions from the midwestern and northeastern US are carried into southeastern Canada. An interim report from the National Acid Precipitation Assessment Program (NAPAP) has assessed that power plants contribute up to 65% of the national annual emissions of SO 2 , and up to 29% of the NO x emissions. It is for these reasons that acid rain control has been given such a priority by legislators

  14. [Women's knowledge of folic acid].

    Science.gov (United States)

    Salgues, Mathilde; Damase-Michel, Christine; Montastruc, Jean-Louis; Lacroix, Isabelle

    2017-06-01

    Many trials have shown that folic acid supplementation before and during pregnancy reduces the risk of neural tube defects in general population. We investigated the knowledge of folic acid in women of child-bearing age. Women of child-bearing age were interviewed by 20 pharmacists living in Haute-Garonne between January and February 2014. One hundred ninety-six women were included in the present study. Out of them, 36% of women never heard of folic acid and 82% were not aware of its benefits. Knowledge was higher in older women, women in a couple and women with higher educational level (Pfolic acid during pregnancy. Moreover, previous studies have shown that French women have low use of folic acid during peri-conceptional period. Information of general population will be required for a better prevention of folic acid-preventable NTDs. Copyright © 2016 Société française de pharmacologie et de thérapeutique. Published by Elsevier Masson SAS. All rights reserved.

  15. Syngas route to adipic acid

    Energy Technology Data Exchange (ETDEWEB)

    Kealing, H.S.

    1986-03-01

    In an era of escalating hydrocarbon prices, the development of new technology to synthesize large volume chemical intermediates from the least expensive sources of carbon and hydrogen has been a research area of increasing intensity. Adipic acid is prepared commercially by oxidative processes using either benzene or phenol as the raw material base. Since both benzene and phenol prices track with the price of crude oil, future adipic acid price will increase as the oil reserve decreases. Thus, there is a need for a new process to produce adipic acid from cheap, and readily available, raw materials such as butadiene obtained as a by-product from world scale olefin plants. One such process that capitalizes on the use of butadiene as a raw material is BASF's two-step carbonylation route to adipic acid. The butadiene in the C/sub 4/ cut from a steam cracker is transformed by a two-stage carbonylation with carbon monoxide and methanol into adipic acid dimethyl ester. Hydrolysis converts the ester into adipic acid. BASF is now engineering a 130 mm pound per year commercial plant based on this technology.

  16. Molecular screening of wine lactic acid bacteria degrading hydroxycinnamic acids.

    Science.gov (United States)

    de las Rivas, Blanca; Rodríguez, Héctor; Curiel, José Antonio; Landete, José María; Muñoz, Rosario

    2009-01-28

    The potential to produce volatile phenols from hydroxycinnamic acids was investigated for lactic acid bacteria (LAB) isolated from Spanish grape must and wine. A PCR assay was developed for the detection of LAB that potentially produce volatile phenols. Synthetic degenerate oligonucleotides for the specific detection of the pdc gene encoding a phenolic acid decarboxylase were designed. The pdc PCR assay amplifies a 321 bp DNA fragment from phenolic acid decarboxylase. The pdc PCR method was applied to 85 strains belonging to the 6 main wine LAB species. Lactobacillus plantarum, Lactobacillus brevis, and Pediococcus pentosaceus strains produce a positive response in the pdc PCR assay, whereas Oenococcus oeni, Lactobacillus hilgardii, and Leuconostoc mesenteroides strains did not produce the expected PCR product. The production of vinyl and ethyl derivatives from hydroxycinnamic acids in culture media was determined by high-performance liquid chromatography. A relationship was found between pdc PCR amplification and volatile phenol production, so that the LAB strains that gave a positive pdc PCR response produce volatile phenols, whereas strains that did not produce a PCR amplicon did not produce volatile phenols. The proposed method could be useful for a preliminary identification of LAB strains able to produce volatile phenols in wine.

  17. [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.

  18. Hepatoprotective bile acid 'ursodeoxycholic acid (UDCA)' Property and difference as bile acids.

    Science.gov (United States)

    Ishizaki, Kaoru; Imada, Teruaki; Tsurufuji, Makoto

    2005-10-01

    Ursodeoxycholic acid (UDCA) is a bile acid, which is present in human bile at a low concentration of only 3% of total bile acids. It is a 7beta-hydroxy epimer of the primary bile acid chenodeoxycholic acid (CDCA). UDCA is isolated from the Chinese drug 'Yutan' a powder preparation derived from the dried bile of adult bears. For centuries, Yutan has been used in the treatment of hepatobiliary disorders. In Japan, it has also been in widespread use as a folk medicine from the mid-Edo period. In Japan, not only basic studies such as isolation, crystallization, definition of the chemical structure and establishment of the synthesis of UDCA have been conducted but clinical studies have been conducted. First reports on the effects of UDCA in patients with liver diseases came from Japan as early as 1961. In the 1970s, the first prospective study of patients with gallbladder stones treated with UDCA demonstrating gallstone dissolution was reported. In late 1980s, a number of controlled trials on the use of UDCA in primary biliary cirrhosis (PBC) were reported. Since then, a variety of clinical studies have shown the beneficial effect of UDCA in liver disease worldwide. To date, UDCA is utilized for the treatment of PBC for which it is the only drug approved by the U.S. Food and Drug Administration (FDA). In recent years, with the advent of molecular tools, the mechanisms of action of bile acids and UDCA have been investigated, and various bioactivities and pharmacological effects have been revealed. Based on the results of these studies, the bioactive substances in bile acids that are involved in digestive absorption may play important roles in signal transduction pathways. Furthermore, the mechanisms of action of UDCA is evidently involved. We reveal the physicochemical properties of UDCA as bile acid and overview the established pharmacological effects of UDCA from its metabolism. Furthermore, we overview the current investigations into the mechanism of action of UDCA in

  19. Kinetic and safety assessment for salicylic acid nitration by nitric acid/acetic acid system.

    Science.gov (United States)

    Andreozzi, R; Caprio, V; Di Somma, I; Sanchirico, R

    2006-06-30

    The nitration process of salicylic acid for the production of the important intermediate 5-nitrosalicylic acid is studied from thermokinetic and safety points of view. Investigations carried out by considering, as process deviations, the loss of the thermal control point out the possibility of runaway phenomena due to the occurrence of polynitration reactions. Isothermal experiments are carried out in various conditions to assess the involved reaction network and reaction kinetics.

  20. Initial acidity of dental cements.

    Science.gov (United States)

    Brune, D; Evje, D M

    1984-04-01

    The acidity in aqueous solutions following release of acid components from glass ionomer, silicate, zinc phosphate and zinc polycarboxylate cements has been registered by pH measurements. One brand of each type was studied. Initial setting was accomplished at two different temperatures; 23 degrees C and in the interval from 23 degrees C to about 60 degrees C. In the latter case external heat was transferred to the samples by infrared radiation for a period of 2 min. The highest acidity was associated with the silicate specimen, while the lowest acidity was recorded for the zinc polycarboxylate specimen. Exposure to infrared radiation resulted in a reduced acidity for all types of cements. The effect of infrared exposure was most pronounced for the silicate specimens, resulting in a reduction of acid release by a factor of about 10 compared to the nontreated samples. The resistance to acid release was found to be improved by a factor of about 5 for the glass ionomer and about 3 for the zinc phosphate cement treated in a similar way. Clinically, it seems possible considerably to reduce the risk of pulpal injuries associated with the insertion of silicate restorations by using a moderate infrared radiation treatment. Furthermore, the susceptibility of glass ionomer cements to a high initial erosion should be reduced by the use of such a technique. After exposure of the glass ionomer and silicate specimens to infrared radiation at the temperature interval applied, the samples had a more glossy, tooth-like appearance compared to the nonexposed samples, improving the aesthetic properties.

  1. 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...... with ps resolved streak camera technology. Structural and fluorescence properties changes induced on HA-PheSA due to the presence of singlet oxygen were monitored using static light scattering (SLS), steady state fluorescence and ps time resolved fluorescence studies. SLS studies provided insight...

  2. Anaerobic biotransformation of organoarsenical pesticides monomethylarsonic acid and dimethylarsinic acid

    Science.gov (United States)

    Sierra-Alvarez, R.; Yenal, U.; Feld, J.A.; Kopplin, M.; Gandolfi, A.J.; Garbarino, J.R.

    2006-01-01

    Monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) are extensively utilized as pesticides, introducing large quantities of arsenic into the environment. Once released into the environment, these organoarsenicals are subject to microbial reactions. Aerobic biodegradation of MMAV and DMAV has been evaluated, but little is known about their fate in anaerobic environments. The objective of this study was to evaluate the biotransformation of MMAV and DMAV in anaerobic sludge. Biologically mediated conversion occurred under methanogenic or sulfate-reducing conditions but not in the presence of nitrate. Monomethylarsonous acid (MMAIII) was consistently observed as an important metabolite of MMAV degradation, and it was recovered in molar yields ranging from 5 to 47%. The main biotransformation product identified from DMAV metabolism was MMAV, which was recovered in molar yields ranging from 8 to 65%. The metabolites indicate that reduction and demethylation are important steps in the anaerobic bioconversion of MMAV and DMAV, respectively. ?? 2006 American Chemical Society.

  3. 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.

  4. 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...... boronate internucleosidic linkages. The DNA- or RNA-templated system comprises a 5′-ended boronic acid probe connecting a 3′-ended ribonucleosidic oligonucleotide partner. To explore the dominant factors that control the reversible linkage, we synthesized a series of 3′-end modified ribonucleotidic strands...

  5. 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

  6. Conjugated Linoleic Acid Accumulation via 10-Hydroxy-12-Octadecaenoic Acid during Microaerobic Transformation of Linoleic Acid by Lactobacillus acidophilus

    OpenAIRE

    Ogawa, Jun; Matsumura, Kenji; Kishino, Shigenobu; Omura, Yoriko; Shimizu, Sakayu

    2001-01-01

    Specific isomers of conjugated linoleic acid (CLA), a fatty acid with potentially beneficial physiological and anticarcinogenic effects, were efficiently produced from linoleic acid by washed cells of Lactobacillus acidophilus AKU 1137 under microaerobic conditions, and the metabolic pathway of CLA production from linoleic acid is explained for the first time. The CLA isomers produced were identified as cis-9, trans-11- or trans-9, cis-11-octadecadienoic acid and trans-9, trans-11-octadecadie...

  7. Fatty acid biosynthesis in actinomycetes

    Science.gov (United States)

    Gago, Gabriela; Diacovich, Lautaro; Arabolaza, Ana; Tsai, Shiou-Chuan; Gramajo, Hugo

    2011-01-01

    All organisms that produce fatty acids do so via a repeated cycle of reactions. In mammals and other animals, these reactions are catalyzed by a type I fatty acid synthase (FAS), a large multifunctional protein to which the growing chain is covalently attached. In contrast, most bacteria (and plants) contain a type II system in which each reaction is catalyzed by a discrete protein. The pathway of fatty acid biosynthesis in Escherichia coli is well established and has provided a foundation for elucidating the type II FAS pathways in other bacteria (White et al., 2005). However, fatty acid biosynthesis is more diverse in the phylum Actinobacteria: Mycobacterium, possess both FAS systems while Streptomyces species have only the multi-enzyme FAS II system and Corynebacterium species exclusively FAS I. In this review we present an overview of the genome organization, biochemical properties and physiological relevance of the two FAS systems in the three genera of actinomycetes mentioned above. We also address in detail the biochemical and structural properties of the acyl-CoA carboxylases (ACCases) that catalyzes the first committed step of fatty acid synthesis in actinomycetes, and discuss the molecular bases of their substrate specificity and the structure-based identification of new ACCase inhibitors with anti-mycobacterial properties. PMID:21204864

  8. 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...

  9. 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...

  10. 21 CFR 184.1097 - Tannic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tannic acid. 184.1097 Section 184.1097 Food and... Substances Affirmed as GRAS § 184.1097 Tannic acid. (a) Tannic acid (CAS Reg. No. 1401-55-4), or hydrolyzable gallotannin, is a complex polyphenolic organic structure that yields gallic acid and either glucose or quinic...

  11. Preparation and activity of glycosylated acetylsalicylic acid

    Directory of Open Access Journals (Sweden)

    Gangliang Huang

    2018-02-01

    Full Text Available The glycosylated acetylsalicylic acid was prepared with bromo-α-d-galactose and acetylsalicylic acid. It indicated that the glycosylated acetylsalicylic acid had lower cytotoxicity than underivatized acetylsalicylic acid, and might selectively display anticancer activity in this situation that had enzyme or no enzyme.

  12. Reactor lower head penetration CO2 cleaning robot

    International Nuclear Information System (INIS)

    Kim, Namkyun; Na, Jongil

    2008-01-01

    The reactor pressure vessel(RPV) heads of PWRs have penetrations for control rod drive mechanisms and instrumentation systems. The bottom heads of PWRs also have penetrations for instrumentation systems. The bottom heads of PWRs also have penetrations for instrumentation. Nickel based alloys(e. g., Alloy 600) are used in the penetration nozzles and related weld. Primary coolant water and operating condition of PWR plant can cause cracking(PWSCC). The susceptibility of RPV head and bottom head to PWSCC appears to be strongly linked to the operating time and temperature of RPV head. After circumferential cracking of the nozzles above the J-groove weld of the RPV heads was reported by the NRC in 2001, licensees in Korea started bare metal visual inspection on the outside surface of the RPV heads and the bottom heads. While performing inspection, many domestic licensees found boric acid crystal deposited around the penetrations of the RPV heads and the bottom heads. The source of the boric acid crystals on the RPV heads and the bottom heads. The source of the boric acid crystals on the RPV heads was the primary water spilled during dynamic venting and the boric acid crystals on the bottom heads were the refueling water leaked through the cavity seal ring while the refueling cavity was filled. Because the identified boric acid crystals affect the reliability of the bare metal inspection, Korea Institute of Nuclear Safety (KINS) recommended that it is required to clean the boric acid deposits for future inspection. In response to the recommendation, we developed the dry ice cleaning robot which is remotely controlled and performs the dry ice blasting. In this paper we will reflect on the bare metal inspections and cleaning method for removal of the boric acid crystal deposited on the bottom heads and the RPV heads. The dry ice cleaning robot successfully cleaned the white residues on the lower heads repeatedly during outage in plants of different designs

  13. 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.

  14. Solid–liquid equilibria measurements for binary systems comprising (butyric acid + propionic or pentanoic acid) and (heptanoic acid + propionic or butyric or pentanoic or hexanoic acid)

    International Nuclear Information System (INIS)

    Tadie, Margreth; Bahadur, Indra; Reddy, Prashant; Ngema, Peterson Thokozani; Naidoo, Paramespri; Deenadayalu, Nirmala; Ramjugernath, Deresh

    2013-01-01

    Highlights: ► Binary SLE measurement for butyric acid + {propionic or pentanoic acid}. ► Binary SLE measurements for heptanoic acid + {propionic or butyric or pentanoic or hexanoic acid}. ► Measurements undertaken using a synthetic method using two new apparati. - Abstract: Solid–liquid equilibria (SLE) measurements have been undertaken for carboxylic acid systems comprising (butyric acid + propionic or pentanoic acid) and (heptanoic acid + propionic or butyric or pentanoic or hexanoic acid) via a synthetic method using two complementary pieces of equipment. The measurements have been obtained at atmospheric pressure and over the temperature range of (225.6 to 270.7) K. All the acid mixtures exhibit a eutectic point in their respective phase diagrams, which have been determined experimentally. The estimated maximum uncertainties in the reported temperatures and compositions are ±1 K and ±0.0006 mole fraction, respectively. The experimental data have been satisfactorily correlated with the Wilson and NRTL activity coefficient models.

  15. 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

  16. 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

  17. 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

  18. Tumor Acidity as Evolutionary Spite

    Energy Technology Data Exchange (ETDEWEB)

    Alfarouk, Khalid O., E-mail: khalid.alfarouk@act.sd [Department of Biotechnology, Africa City of Technology, Khartoum (Sudan); Department of Pharmaceutics, Faculty of Pharmacy, University of Khartoum, Khartoum (Sudan); Muddathir, Abdel Khalig [Department of Pharmacognosy, Faculty of Pharmacy, University of Khartoum, Khartoum (Sudan); Shayoub, Mohammed E. A. [Department of Pharmaceutics, Faculty of Pharmacy, University of Khartoum, Khartoum (Sudan)

    2011-01-20

    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.

  19. PHENOLIC ACIDS AND LIGNINS IN THE LYCOPODIALES,

    Science.gov (United States)

    ethanolysis or alkaline oxidation of their extracted wood-meals. p-Hydroxybenzoic, vanillic, p-coumaric and ferulic acids were identified in phenolic acid ...Twenty-one species and varieties of Lycopodium have been examined for phenolic acids and for phenolic aldehydes, ketones and acids obtained on...found to yield syringic acid in the ethanol-soluble fraction and on degradation of lignin whereas species included in the genera Huperzia and Lepidotis

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. Effect of para-chlorophenoxyacetic acid on acid invertase gene ...

    African Journals Online (AJOL)

    Your User Name

    2011-07-04

    Jul 4, 2011 ... enzymes and the effects of PCPA treatment on gene expression of soluble acid invertase (AI) during tomato fruit development were .... with DIG high prime DNA labelling and detection starter kit II. (Roche). RESULTS. Effect of ... during this time, sucrose content of fruit from the treated plants was slightly ...

  5. 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+] > ...

  6. 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 ...

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

    Indian Academy of Sciences (India)

    IAS Admin

    developed by Barton (1969 Chemistry Nobel Prize) to the solution of an important configurational problem, as we shall see. The presently accepted structure of abietic acid is the result of intensive chemical researches extending over a period of more than a century. The subject is an important part of authoritative treatises.

  8. 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+] > ...

  9. by treatment with crotonic acid and vinyl acetic acid

    Indian Academy of Sciences (India)

    random access memory devices and energy storage devices. Electrolytes, polyelectrolytes or their complexes in ... with alkali-metal salts or metal salts or acids.2,6,7. Measurement of conductivity in solid state shows ..... part and Z sin θ is the imaginary part denoted as Z′ real and. Z′′ imag, respectively. In this way for the ...

  10. 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 ...

  11. 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 ...

  12. Fatty acids and amino acids contents in Scomber scombrus fillets ...

    African Journals Online (AJOL)

    The highest rates were noted for phenylalanine, valine, threonine, isoleucine, leucine and methionine. It was concluded that Atlantic Mackerel was high in interesting human feeding nutriments, mainly PUFA and essential amino Acids. Even when significant, differences between seasons were not drastic and S. scombrus ...

  13. CACODYLIC ACID (DMAV): METABOLISM AND ...

    Science.gov (United States)

    The cacodylic acid (DMAV) issue paper discusses the metabolism and pharmacokinetics of the various arsenical chemicals; evaluates the appropriate dataset to quantify the potential cancer risk to the organic arsenical herbicides; provides an evaluation of the mode of carcinogenic action (MOA) for DMAV including a consideration of the key events for bladder tumor formation in rats, other potential modes of action; and also considers the human relevance of the proposed animal MOA. As part of tolerance reassessment under the Food Quality Protection Act for the August 3, 2006 deadline, the hazard of cacodylic acid is being reassessed.

  14. 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.

  15. 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

  16. Spherical agglomeration of acetylsalicylic acid

    Directory of Open Access Journals (Sweden)

    Polowczyk Izabela

    2016-01-01

    Full Text Available In this paper spherical agglomeration of acetylsalicylic acid was described. In the first step, the system of good and poor solvents as well as bridging liquid was selected. As a result of a preliminary study, ethyl alcohol, water and carbon tetrachloride were used as the good solvent, poor one, and bridging liquid, respectively. Then, the amount of acetylsalicylic acid and the ratio of the solvents as well as the volume of the bridging liquid were examined. In the last step, the agglomeration conditions, such as mixing intensity and time, were investigated. The spherical agglomerates obtained under optimum conditions could be subjected to a tableting process afterwards.

  17. 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.

  18. Health benefits of n-3 polyunsaturated fatty acids: eicosapentaenoic acid and docosahexaenoic acid.

    Science.gov (United States)

    Siriwardhana, Nalin; Kalupahana, Nishan S; Moustaid-Moussa, Naima

    2012-01-01

    Marine-based fish and fish oil are the most popular and well-known sources of n-3 polyunsaturated fatty acids (PUFAs), namely, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These n-3 PUFAs are known to have variety of health benefits against cardiovascular diseases (CVDs) including well-established hypotriglyceridemic and anti-inflammatory effects. Also, various studies indicate promising antihypertensive, anticancer, antioxidant, antidepression, antiaging, and antiarthritis effects. Moreover, recent studies also indicate anti-inflammatory and insulin-sensitizing effects of these fatty acids in metabolic disorders. Classically, n-3 PUFAs mediate some of these effects by antagonizing n-6 PUFA (arachidonic acid)-induced proinflammatory prostaglandin E₂ (PGE₂) formation. Another well-known mechanism by which n-3 PUFAs impart their anti-inflammatory effects is via reduction of nuclear factor-κB activation. This transcription factor is a potent inducer of proinflammatory cytokine production, including interleukin 6 and tumor necrosis factor-α, both of which are decreased by EPA and DHA. Other evidence also demonstrates that n-3 PUFAs repress lipogenesis and increase resolvins and protectin generation, ultimately leading to reduced inflammation. Finally, beneficial effects of EPA and DHA in insulin resistance include their ability to increase secretion of adiponectin, an anti-inflammatory adipokine. In summary, n-3 PUFAs have multiple health benefits mediated at least in part by their anti-inflammatory actions; thus their consumption, especially from dietary sources, should be encouraged. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Modulating the electronic structure of amino acids: interaction of model lewis acids with anthranilic acid

    Directory of Open Access Journals (Sweden)

    Tareq Irshaidat

    2014-01-01

    Full Text Available On the basis of theoretical B3LYP calculations, Yáñez and co-workers (J. Chem. Theory Comput. 2012, 8, 2293 illustrated that beryllium ions are capable of significantly modulating (changing the electronic structures of imidazole. In this computational organic chemistry study, the interaction of this β-amino acid and five model Lewis acids (BeF1+, Be2+, AlF2(1+, AlF2+, and Al3+ were investigated. Several aspects were addressed: natural bond orbitals, including second order perturbation analysis of intra-molecular charge delocalization and the natural population analysis atomic charges; molecular geometries; selected infrared stretching frequencies (C-N, C-O, and N-H, and selected ¹H-NMR chemical shifts. The data illustrate that this interaction can weaken the H-O bond and goes beyond strengthening the intra-molecular hydrogen bond (N...H-O to cause a spontaneous transfer of the proton to the nitrogen atom in five cases generating zwitterion structures. Many new features are observed. Most importantly, the zwitterion structures include a stabilizing hydrogen bond (N-H...O that varies in relative strength according to the Lewis acid. These findings explain the experimental observations of α-amino acids (for example: J. Am. Chem. Soc. 2001, 123, 3577 and are the first reported fundamental electronic structure characterization of β-amino acids in zwitterion form.

  20. 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)

  1. Acid Rain: What It Is -- How You Can Help!

    Science.gov (United States)

    National Wildlife Federation, Washington, DC.

    This publication discusses the nature and consequences of acid precipitation (commonly called acid rain). Topic areas include: (1) the chemical nature of acid rain; (2) sources of acid rain; (3) geographic areas where acid rain is a problem; (4) effects of acid rain on lakes; (5) effect of acid rain on vegetation; (6) possible effects of acid rain…

  2. 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.

  3. 40 CFR 180.550 - Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ...) arsonic acid]; tolerances for residues. 180.550 Section 180.550 Protection of Environment ENVIRONMENTAL... FOOD Specific Tolerances § 180.550 Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for... arsanilic acid [(4-aminophenyl) arsonic acid], in or on the following food commodities in connection with...

  4. Hydroxylated analogues of 5-aminovaleric acid as 4-aminobutyric acidB receptor antagonists

    DEFF Research Database (Denmark)

    Kristiansen, U; Hedegaard, A; Herdeis, C

    1992-01-01

    The (R) and (S) forms of 5-amino-2-hydroxyvaleric acid (2-OH-DAVA) and 5-amino-4-hydroxyvaleric acid (4-OH-DAVA) were designed as structural hybrids of the 4-aminobutyric acidB (GABAB) agonist (R)-(-)-4-amino-3-hydroxybutyric acid [(R)-(-)-3-OH-GABA] and the GABAB antagonist 5-aminovaleric acid...

  5. 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

  6. 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...

  7. 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.

  8. Analysis of proteins responsive to acetic acid in Acetobacter: molecular mechanisms conferring acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Nakano, Shigeru; Fukaya, Masahiro

    2008-06-30

    Acetic acid bacteria are used for industrial vinegar production because of their remarkable ability to oxidize ethanol and high resistance to acetic acid. Although several molecular machineries responsible for acetic acid resistance in acetic acid bacteria have been reported, the entire mechanism that confers acetic acid resistance has not been completely understood. One of the promising methods to elucidate the entire mechanism is global analysis of proteins responsive to acetic acid by two-dimensional gel electrophoresis. Recently, two proteins whose production was greatly enhanced by acetic acid in Acetobacter aceti were identified to be aconitase and a putative ABC-transporter, respectively; furthermore, overexpression or disruption of the genes encoding these proteins affected acetic acid resistance in A. aceti, indicating that these proteins are involved in acetic acid resistance. Overexpression of each gene increased acetic acid resistance in Acetobacter, which resulted in an improvement in the productivity of acetic acid fermentation. Taken together, the results of the proteomic analysis and those of previous studies indicate that acetic acid resistance in acetic acid bacteria is conferred by several mechanisms. These findings also provide a clue to breed a strain having high resistance to acetic acid for vinegar fermentation.

  9. 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.

  10. 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

  11. 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.

  12. 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)

  13. 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

  14. 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)

  15. 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.

  16. N-heterocyclic carboxylic acids

    Indian Academy of Sciences (India)

    Administrator

    2,3-dicarboxylic acid) is solved by single crystal X-ray diffraction technique. Antibacterial activities of the complexes are evaluated by determining their capacity to inhibit the growth of E. coli 10536 (MIC) in a nutrient broth. Proc. Indian Acad. Sci. (Chem. Sci.), Vol. 112, No. 3, June 2000, p. 355. © Indian Academy of Sciences.

  17. Hydrogenation using hydrides and acid

    Science.gov (United States)

    Bullock, R. Morris

    1990-10-30

    A process for the non-catalytic hydrogenation of organic compounds, which contain at least one reducible functional group, which comprises reacting the organic compound, a hydride complex, preferably a transition metal hydride complex or an organosilane, and a strong acid in a liquid phase.

  18. 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

  19. Acid mine drainage - the chemistry

    CSIR Research Space (South Africa)

    Garland, Rebecca M

    2011-01-01

    Full Text Available Soapy Water Ammonia Solution Milk of Magnesia Baking Soda Sea Water Distilled Water Urine Black Co�ee Tomato Juice Orange Juice Lemon Juice Gastric Acid The solid precipitate that is called ?yellow boy?. Image: Rebecca Garland ? The vision...

  20. Diterpene resin acids in conifers.

    Science.gov (United States)

    Keeling, Christopher I; Bohlmann, Jörg

    2006-11-01

    Diterpene resin acids are a significant component of conifer oleoresin, which is a viscous mixture of terpenoids present constitutively or inducibly upon herbivore or pathogen attack and comprises one form of chemical resistance to such attacks. This review focuses on the recent discoveries in the chemistry, biosynthesis, molecular biology, regulation, and biology of these compounds in conifers.