Boric acid solubility in the presence of alkali metal nitrides

Energy Technology Data Exchange (ETDEWEB)

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

1983-01-01

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

Boric acid solubility in the presence of alkali metal nitrides

International Nuclear Information System (INIS)

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

1983-01-01

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

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.

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-05-01

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

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

Science.gov (United States)

2010-07-01

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

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.

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.

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

Experimental observations of boric acid precipitation scenarios

Energy Technology Data Exchange (ETDEWEB)

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

2017-02-15

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

Boric Acid Corrosion of Concrete Rebar

Directory of Open Access Journals (Sweden)

Yang L.

2013-07-01

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

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

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.

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

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

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

International Nuclear Information System (INIS)

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

1985-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1985-07-01

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

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 ...

CEC mechanism in electrochemical oxidation of nitrocatechol-boric acid complexes

International Nuclear Information System (INIS)

Rafiee, Mohammad; Nematollahi, Davood; Salehzadeh, Hamid

2011-01-01

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

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...

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-12-15

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

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

International Nuclear Information System (INIS)

Stone, M.

2010-01-01

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

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

International Nuclear Information System (INIS)

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

1987-01-01

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

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)

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

Chloride stress corrosion cracking of Alloy 600 in boric acid solutions

International Nuclear Information System (INIS)

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

1997-10-01

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

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

Directory of Open Access Journals (Sweden)

Zahir Kizilay

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1985-03-01

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

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-

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...

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...

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

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

Science.gov (United States)

2010-07-01

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

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

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

Science.gov (United States)

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

2014-09-01

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

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

African Journals Online (AJOL)

ufuoma

2013-05-01

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

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

International Nuclear Information System (INIS)

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

1995-01-01

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

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

International Nuclear Information System (INIS)

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

1993-10-01

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

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

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.

Management of Azole-Refractory Candida Species Using Boric Acid

African Journals Online (AJOL)

Mgina

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

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

Science.gov (United States)

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

2017-02-01

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

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

Directory of Open Access Journals (Sweden)

LIU Hui-cong

2016-07-01

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

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....

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)

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.

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.

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

African Journals Online (AJOL)

STORAGESEVER

2009-02-18

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

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.

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

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.)

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

International Nuclear Information System (INIS)

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

2005-01-01

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

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

Science.gov (United States)

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

2016-01-01

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

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 ...

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

Energy Technology Data Exchange (ETDEWEB)

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

2002-09-01

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

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

Boric Acid Catalyzed Convenient Synthesis of Benzimidazoles in Aqueous Media

Directory of Open Access Journals (Sweden)

Mohammad Reza Poor Heravi

2013-01-01

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

Boric Acid Catalyzed Convenient Synthesis of Benzimidazoles in Aqueous Media

OpenAIRE

Poor Heravi, Mohammad Reza; Ashori, Marjan

2013-01-01

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

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.

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

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)

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

International Nuclear Information System (INIS)

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

1991-01-01

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

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

International Nuclear Information System (INIS)

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

2006-01-01

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

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

International Nuclear Information System (INIS)

Bahdir-Johan

2000-01-01

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

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.

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.

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.

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

Science.gov (United States)

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

2016-09-01

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

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...

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.

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...

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

DEFF Research Database (Denmark)

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

2011-01-01

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

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.

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.

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)

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

International Nuclear Information System (INIS)

Fisera, O.

2010-01-01

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

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)

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)

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...

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.

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.

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.

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 ...

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.

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

Science.gov (United States)

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

2006-09-01

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

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

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

Science.gov (United States)

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

2018-04-01

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-11-15

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

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

International Nuclear Information System (INIS)

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

2007-01-01

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

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

Directory of Open Access Journals (Sweden)

Naser Nasrolahzadehasl

2017-10-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-12-15

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

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.

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

International Nuclear Information System (INIS)

Sumijanto; Siti-Amini

1996-01-01

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

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

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

Directory of Open Access Journals (Sweden)

Zahed Karimi-Jaberi

2012-12-01

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

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

Science.gov (United States)

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

2017-04-11

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

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

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

International Nuclear Information System (INIS)

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

2000-01-01

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-11-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-06-15

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

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.

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)

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.

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

International Nuclear Information System (INIS)

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

1997-01-01

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

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

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

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.

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 ...

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.

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.

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

Science.gov (United States)

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

2008-11-06

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

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.

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-03-21

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

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

Science.gov (United States)

Brdicka, R

1936-07-20

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

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

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

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)

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

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

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.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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

Introduction - Acid decomposition of borosilicate ores

International Nuclear Information System (INIS)

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

2015-01-01

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

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)

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

International Nuclear Information System (INIS)

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

2011-01-01

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

The development of radioactive waste treatment technology (III)

International Nuclear Information System (INIS)

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

1991-03-01

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

Method of processing radioactive liquid wastes

Energy Technology Data Exchange (ETDEWEB)

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

1978-12-21

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

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

OpenAIRE

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

2015-01-01

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

4.2. 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%.

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

Acid-permanganate oxidation of potassium tetraphenylboron

International Nuclear Information System (INIS)

Smith, J.R.

1993-02-01

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

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)

Improving pitting corrosion resistance of aluminum by anodizing process

International Nuclear Information System (INIS)

John, P.; Khan, I.U.

2013-01-01

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

Ecofriendly Fire Retardant and Rot Resistance Finishing of Jute Fabric Using Tin and Boron Based Compound

Science.gov (United States)

Samanta, Ashis Kumar; Bagchi, Arindam

2017-06-01

Treatment with sodium stannate followed by treatment with boric acid imparts jute fabric wash fast fire resistance property as indicated by its Limiting Oxygen Index (LOI) value and 45° inclined flammability test results. The treatment was carried out by impregnation of sodium stannate followed by impregnation with an aqueous solution of boric acid and drying. Application of sodium stannate (20%) and boric acid (20%) treatment on jute fabric showed balanced flame retardancy property (LOI value 34) with some loss in fabric tenacity (loss of tenacity is 14.5%). Treated fabric retained good fire retardant property after three consecutive washing. Treated fabric also possessed good rot resistance property as indicated by soil burial test and strength retention after 21 days soil burial was found to be 65%. It is found that of sodium stannate and boric acid combination by double bath process form a synergistic durable fire-retardant as well as rot resistant when impregnated on jute material, which is considerably greater than the use of either sodium stannate or boric acid alone. TGA, FTIR and SEM analysis are also reported to support the results and reaction mechanism.

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)

The Impact Of The MCU Life Extension Solvent On Sludge Batch 8 Projected Operating Windows

International Nuclear Information System (INIS)

Peeler, D. K.; Edwards, T. B.; Stone, M. E.

2013-01-01

As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NGS) and a new strip acid will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing or evaluations with the next generation solvent are required to determine the impact of these changes (if any) to Chemical Process Cell (CPC) activities, glass formulation strategies, and melter operations at the Defense Waste Processing Facility (DWPF). The introduction of the dilute (0.01M) boric acid stream into the DWPF flowsheet has a potential impact on glass formulation and frit development efforts since B2O3 is a major oxide in frits developed for DWPF. Prior knowledge of this stream can be accounted for during frit development efforts but that was not the case for Sludge Batch 8 (SB8). Frit 803 has already been recommended and procured for SB8 processing; altering the frit to account for the incoming boron from the strip effluent (SE) is not an option for SB8. Therefore, the operational robustness of Frit 803 to the introduction of SE including its compositional tolerances (i.e., up to 0.0125M boric acid) is of interest and was the focus of this study. The primary question to be addressed in the current study was: What is the impact (if any) on the projected operating windows for the Frit 803 - SB8 flowsheet to additions of B2O3 from the SE in the Sludge Receipt and Adjustment Tank (SRAT)? More specifically, will Frit 803 be robust to the potential compositional changes occurring in the SRAT due to sludge variation, varying additions of ARP and/or the introduction of SE by providing access to waste loadings (WLs) of interest to DWPF? The Measurement Acceptability Region (MAR) results indicate there is very little, if any, impact on the projected operating windows for the Frit 803 - SB8 system regardless of the presence or absence of

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.

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

African Journals Online (AJOL)

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

Enrichment of boron 10

International Nuclear Information System (INIS)

Coutinho, C.M.M.; Rodrigues Filho, J.S.R.; Umeda, K.; Echternacht, M.V.

1990-01-01

A isotopic separation pilot plant with five ion exchange columns interconnected in series were designed and built in the IEN. The columns are charged with a strong anionic resin in its alkaline form. The boric acid solution is introduced in the separation columns until it reaches a absorbing zone length which is sufficient to obtain the desired boron-10 isotopic concentration. The boric acid absorbing zone movement is provided by the injection of a diluted hydrochloric acid solution, which replace the boric acid throughout the columns. The absorbing zone equilibrium length is proportional to its total length. The enriched boron-10 and the depleted boron are located in the final boundary and in the initial position of the absorbing zones, respectively. (author)

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.)

The Impact Of The Mcu Life Extension Solvent On Dwpf Glass Formulation Efforts

International Nuclear Information System (INIS)

Peeler, D.; Edwards, T.

2011-01-01

As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NG-CSSX), a new strip acid, and modified monosodium titanate (mMST) will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing with the next generation solvent and mMST is required to determine the impact of these changes in 512-S operations as well as Chemical Process Cell (CPC), Defense Waste Processing Facility (DWPF) glass formulation activities, and melter operations at DWPF. To support programmatic objectives, the downstream impacts of the boric acid strip effluent (SE) to the glass formulation activities and melter operations are considered in this study. More specifically, the impacts of boric acid additions to the projected SB7b operating windows, potential impacts to frit production temperatures, and the potential impact of boron volatility are evaluated. Although various boric acid molarities have been reported and discussed, the baseline flowsheet used to support this assessment was 0.01M boric acid. The results of the paper study assessment indicate that Frit 418 and Frit 418-7D are robust to the implementation of the 0.01M boric acid SE into the SB7b flowsheet (sludge-only or ARP-added). More specifically, the projected operating windows for the nominal SB7b projections remain essentially constant (i.e., 25-43 or 25-44% waste loading (WL)) regardless of the flowsheet options (sludge-only, ARP added, and/or the presence of the new SE). These results indicate that even if SE is not transferred to the Sludge Receipt and Adjustment Tank (SRAT), there would be no need to add boric acid (from a trim tank) to compositionally compensate for the absence of the boric acid SE in either a sludge-only or ARP-added SB7b flowsheet. With respect to boron volatility, the Measurement Acceptability Region (MAR) assessments also

Development of automatic high-concentration boron measurement technique; Konodo hoso jido sokutei gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Maeda, T.; Honda, S.; Ito, A. [Kyushu Electric Power Co. Inc., Fukuoka (Japan)

1997-03-01

The technology that can automatically measure the boron concentration in boric acid water was developed. A high-concentration boric acid solution must be held at a high temperature to prevent the deposition. Skill and precision ({plus_minus}0.2 to 0.3% for 10 to 2500 ppm as boron concentration, and {plus_minus}2 to 3% for 2500 to 25,000 ppm) are required to analyze the boric acid solution manually. In theory, the boron concentration in a wide range can be measured, and boron has a constant-temperature function. A density hydrometer method that facilitates the treatment and calibration in high precision and at low cost was chosen. The vibration period generated when vibration is given to the solution specimen put in a U-tube is higher as the density is lower. On the basis of this theory, the density of a specimen can be obtained according to the relation with the same data of the known-concentration boric acid water. The high-concentration boric acid water that cannot be measured by the existing boron densitometer can be measured directly. It can also be measured in a low-concentration area. The technique can be used in a laboratory as the simplified method that is replaced by the current manual analysis. The reduction effect of analytical chemical`s waste liquid can also be expected. In the electric power industry, automated equipment is required for high efficiency and labor saving. 13 figs., 3 tabs.

Effects of radiation and impurities on gaseous iodine behavior in a containment vessel

International Nuclear Information System (INIS)

Takahashi, Masato; Watanabe, Atsushi; Hashimoto, Takashi

2000-01-01

In order to estimate the effect of impurities and radiation on gaseous iodine behavior in containment vessel, NUPEC has improved IMPAIR-3 code developed by PSI. Several modifications on the iodine oxidation by radiolysis and the production of nitric acid, the existence of boric acid, and the reaction of silver particle with iodine were newly added in evaluating the effect of radiolysis and impurities. pH change resulting from presence of boric acid, nitric acid production by radiolysis of air, and sodium hydroxide addition by AM operation, was also considered. The code verification for pH change was performed using the RTF experimental results. Additionally, the effects of boric acid and silver impurities on gaseous iodine behavior were evaluated by the sensitivity analysis. As a result, the experimental results of iodine concentration transient under pH change were well simulated. The following results were also obtained from the sensitive analysis. The gaseous iodine behavior was not affected by the existence of boric acid. In the case of silver existence in liquid phase, the gaseous iodine concentration rapidly decreased because a large amount of iodine changed into AgI species in liquid phase. The restraint effect of silver on gaseous iodine, production was larger than that of pH change. (author)

Advanced boron soaking procedure for steam generators

International Nuclear Information System (INIS)

Ueno, T.; Tsuge, A.; Kawanishi, K.; Ochi, T.; Kadokami, E.

1991-01-01

An experimental study on boric acid penetration into tube to tube-support-plate crevices and Inter-Granular-Attack (hereinafter called 'IGA') cracks in crevices has been performed to obtain the optimum boric acid soaking procedure in operating steam generators with IGA. The penetration rate into the crevice is closely related to various parameters such as heat flux, crevice gap, and porosity of the sludge deposited in crevices. Two experimental crevice models were set up. One was of the packed crevice type; crevice gap is completely packed by sludge, and the other was of the open crevice type; crevice gap is not packed, but reduced by sludge. The porosity of the crevice varied from 100% open porosity to the highly sludge packed porosity of 10∼20%. The relation between heat flux and boric acid penetration rate of the packed crevice type was investigated. For the open crevice type, from the viewpoint that boric acid penetration into the dryout region produces no effects, tube wall superheat in the crevice was measured in order to obtain the dryout heat flux. And it was investigated the boron in IGA cracks using Ion Micro Analysis in order to confirm existence of an anticorrosive film in IGA propagation. The optimum reactor power for effective boric acid penetration onto the tube surface and into the IGA cracks within the tube to tube-support-plate crevice was found to be about a 5% and 30% power level, which are applicable to both the packed and open crevice type. (author)

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

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.

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

Directory of Open Access Journals (Sweden)

Daniel Hernandez-Patlan

2018-06-01

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

3M"T"M neutron quench. Compounds with substantial water solubility and boron content

International Nuclear Information System (INIS)

Cook, Kevin S.; Blake, Alex B.; Neef, C. Jody

2014-01-01

Of the two naturally occurring isotopes of boron ("1"1B 80%, "1"0B 20%), "1"0B is a good neutron absorber with a thermal neutron absorption cross section of ∼3800 barns. The ability to absorb thermal neutrons while producing benign reaction products makes boron an ideal atom to aid in the control and arrest of the fission reaction in nuclear power reactors. In current practice, boric acid and sodium pentaborate are commonly used as neutron absorbers in the water regime of active and passive safety systems. 3M"T"M Neutron Quench compounds have been developed to be applied in situations where criticality control needs exceed normal control methods. In this type of situation these compounds have several advantages over commonly used neutron absorbers like boric acid: Boron Content; compounds contain up to 80 wt% boron compared to 16 wt% for boric acid and sodium pentaborate. Solubility; >16 g B/100 g solution compared to 0.6 g B/100 g solution for boric acid at 25°C. pH neutrality; compounds demonstrate pH neutrality even in concentrated solutions. Thermal Stability; Compounds are stable as solids at temperatures greater than 500°C. Corrosiveness; Electrochemical corrosion rate studies have indicated that these compounds are significantly less corrosive than boric acid. Use of 3M"T"M Neutron Quench can lead to reduction in emergency shutdown pool size, reduce or remove the necessity for pool heating and heat tracing of lines, allow for more rapid introduction of the absorber in emergency situations or be used in other applications where significant neutron control is necessary. (author)

Optimization of crosslinked poly(vinyl alcohol) nanocomposite films for mechanical properties.

Science.gov (United States)

Rouhi, Milad; Razavi, Seyed Hadi; Mousavi, Seyed Mohammad

2017-02-01

The effects of glycerol, bacterial cellulose nanocrystal (BCNC) and boric acid concentrations on the mechanical properties of PVA based films, including ultimate tensile strength (UTS), elongation at break (EAB), tensile Young's modulus (TYM), tensile toughness to break (TT), ultimate puncture strength (UPS), puncture deformation (PD), puncture Young's modulus (PYM) and puncture toughness to break (PT), were scrutinized using a response surface methodology-central composite rotatable design (RSM-CCRD). Second-order polynomial models with high R 2 values ranging from 0.945 to 0.977 were developed for the studied responses using multiple linear regression analysis. The models showed the maximum UTS (72.84MPa), EAB (293.43%), UPS (4.64MPa) and PD (31.80%) could be achieved at 13.89% glycerol concentration, 5.00% BCNC concentration and a boric acid content of 1.96%. The predicted values for optimum conditions were in good agreement with experimental data. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the formation of intramolecular and intermolecular hydrogen and ether crosslinkages in PVA and/or BCNC chains when boric acid is applied. Results showed that PVA/BCNC nanocomposite films plasticized with glycerol and crosslinked with boric acid showed appropriate mechanical properties that made them suitable as a disposable packaging film. Copyright © 2016 Elsevier B.V. All rights reserved.

Chemical enhancement of crevice flushing: Volume 2, Data documentation: Final report

International Nuclear Information System (INIS)

Baum, A.J.; Prestegiacomo, J.B.

1987-06-01

The primary objective of this project was to evaluate the effect of various chemical additives on enhancing the hideout return produced during tubesheet crevice flushing operations in PWR steam generators. Secondary objectives included determining if flushing was an effective means of introducing a corrosion inhibitor into deep tubesheet crevices, and evaluating the effects of different degrees of crevice restriction, different initial crevice chemistries, and different flushing processes. Testing was unable to identify a single additive formulation which increased the flushing effectiveness for all degrees of crevice restriction considered. Testing did reveal that a combination of surfactant (Surfynol 104) and boric acid enhances the flushing effectiveness in tests with moderately restricted crevices. Although cleaning agents were found to increase the flushing effectiveness in tests with extensively restricted crevices, potential corrosion concerns and relatively high contaminant (sodium) levels could discourage their use. However, the testing demonstrated that flushing was an effective means of accumulating a corrosion inhibitor, such as boric acid, in deep tubesheet crevices. Companion testing also indicated that boric acid which accumulated in a tubesheet crevice during crevice flushing was likely to remain in the crevice during subsequent power operation. Consequently, use of boric acid as an additive in tubesheet crevice flushing operations is strongly recommended

Composition and method for coke retardant during hydrocarbon processing

International Nuclear Information System (INIS)

Reid, D.K.

1988-01-01

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

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

OpenAIRE

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

2017-01-01

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

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.

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

Efficacy of commercial baits and new active ingredients against firebrats and silverfish (Zygentoma: Lepismatidae).

Science.gov (United States)

Sims, Steven R; Appel, Arthur G

2012-08-01

Commercial baits containing boric acid, hydramethynon, and indoxacarb were tested against the firebrat, Thermobia domestica (Packard), and silverfish, Lepisma saccharina L. (both Zygentoma: Lepismatidae), under laboratory conditions. Three boric acid baits were consumed in significantly smaller amounts than untreated control food and did not effectively control either species. Baits containing hydramethylnon and indoxacarb were consumed in greater amounts than boric acid baits, but were relatively ineffective, with LT50 values >9 d. Presence or absence of competitive untreated food did not consistently affect bait efficacy. A ground oat matrix was used to evaluate the potential effectiveness of abamectin, chlorfenapyr, dinotefuran, fipronil, hydramethylnon, metaflumizone, and novaluron baits. The most effective compound was chlorfenapyr. At 0.05 and 0.20% (wt:wt) rates, chlorfenapyr baits produced LT50 values, for both species, ranging from 2 to 4 d. All other compounds had LT50 values >7 d.

Solidification of low-level radioactive wastes in masonry cement

International Nuclear Information System (INIS)

Zhou, H.; Colombo, P.

1987-03-01

Portland cements are widely used as solidification agents for low-level radioactive wastes. However, it is known that boric acid wastes, as generated at pressurized water reactors (PWR's) are difficult to solidify using ordinary portland cements. Waste containing as little as 5 wt % boric acid inhibits the curing of the cement. For this purpose, the suitability of masonry cement was investigated. Masonry cement, in the US consists of 50 wt % slaked lime (CaOH 2 ) and 50 wt % of portland type I cement. Addition of boric acid in molar concentrations equal to or less than the molar concentration of the alkali in the cement eliminates any inhibiting effects. Accordingly, 15 wt % boric acid can be satisfactorily incorporated into masonry cement. The suitability of masonry cement for the solidification of sodium sulfate wastes produced at boiling water reactors (BWR's) was also investigated. It was observed that although sodium sulfate - masonry cement waste forms containing as much as 40 wt % Na 2 SO 4 can be prepared, waste forms with more than 7 wt % sodium sulfate undergo catastrophic failure when exposed to an aqueous environment. It was determined by x-ray diffraction that in the presence of water, the sulfate reacts with hydrated calcium aluminate to form calcium aluminum sulfate hydrate (ettringite). This reaction involves a volume increase resulting in failure of the waste form. Formulation data were identified to maximize volumetric efficiency for the solidification of boric acid and sodium sulfate wastes. Measurement of some of the waste form properties relevant to evaluating the potential for the release of radionuclides to the environment included leachability, compression strengths and chemical interactions between the waste components and masonry cement. 15 refs., 19 figs., 9 tabs

Reverse osmosis and its use at the nuclear power plants. Purification of primary circuit coolant by the means of reverse osmosis

International Nuclear Information System (INIS)

Kus, Pavel; Vonkova, Katerina; Kunesova, Katerina; Bartova, Sarka; Skala, Martin; Moucha, Tomáš

2014-01-01

This contribution is focused on the use of membrane technologies (e.g. reverse osmosis) for the primary coolant purification at the nuclear power plants. Currently, boric acid present in the primary coolant is preconcentrated at the evaporators, but their operation is very inefficient and expensive. Therefore, reverse osmosis was proposed as one of promising methods possibly replacing evaporators. The aim of the purification process is to achieve boric acid solution of a defined concentration (40 g/l) in the retentate stream in order to recycle it and reuse it in the primary circuit. Additionally, permeate flow should consist solely of pure water. To study the efficiency of several reverse osmosis modulus in the boric acid removal form the water solutions, experimental apparatus was constructed in our laboratory. It consists of the solution reservoir, pump and reverse osmosis modulus. The arrangement of experiments was batch and the retentate flow was refluxed to the feed solution. Several modulus of commercial reverse osmosis membranes were tested. The feed solution contained various concentrations of H 3 BO 3 , KOH, LiOH and NH 3 in order to simulate real primary coolant composition. Based on the experimental results, mathematical model was developed in order to optimize experimental conditions for the best results in primary coolant purification and boric acid preconcentration. (author)

Kinetic and Mechanistic Study of the pH-Dependent Activation (Epoxidation) of Prodrug Treosulfan Including the Reaction Inhibition in a Borate Buffer.

Science.gov (United States)

Romański, Michał; Ratajczak, Whitney; Główka, Franciszek

2017-07-01

A prodrug treosulfan (T) undergoes a pH-dependent activation to epoxide derivatives. The process seems to involve an intramolecular Williamson reaction (IWR) but clear kinetic evidence is lacking. Moreover, a cis-diol system present in the T structure is expected to promote complexation with boric acid. As a result, the prodrug epoxidation would be inhibited; however, this phenomenon has not been investigated. In this article, the effect of pH on the kinetics of T conversion to its monoepoxide was studied from a mechanistic point of view. Also, the influence of boric acid on the reaction kinetics was examined. The rate constants observed for the activation of T (k obs ) in acetate, phosphate, and carbonate buffers satisfied the equation logk obs  = -7.48 + 0.96 pH. The reaction was inhibited in the excess of boric acid over T, and the k obs decreased with increasing borate buffer concentration. The experimental results were consistent with the inhibition model that included the formation of a tetrahedral, anionic T-boric acid monoester. To conclude, in nonborate buffers, the T activation to (2S,3S)-1,2-epoxybutane-3,4-diol 4-methanesulfonate follows IWR mechanism. A borate buffer changes the reaction kinetics and complicates kinetic analysis. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

An X-ray fluorescence method for the determination of Ba, Sr, Mo and Bi in thorium oxide

International Nuclear Information System (INIS)

Dixit, R.M.; Deshpande, S.S.

1988-01-01

A simple and rapid X-ray fluorescence method for the determination of Ba, Sr, Mo and Bi in thoria is described. Thorium oxide samples are dry-mixed thoroughly with pure boric acid in the ratio of 9:1. One gram of mixture is pressed as a double layer over a primary boric acid pellet. The precision and accuracy of the method have been determined. The power limits of detection are found to be around 20 ppm for most analytes. (author). 5 tables

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%.

Co-melting technology in resource recycling of sludge derived from stone processing.

Science.gov (United States)

Hu, Shao-Hua; Hu, Shen-Chih; Fu, Yen-Pei

2012-12-01

Stone processing sludge (SPS) is a by-product of stone-processing wastewater treatment; it is suitable for use as a raw material for making artificial lightweight aggregates (ALWAs). In this study, boric acid was utilized as a flux to lower sintering temperature. The formation of the viscous glassy phase was observed by DTA curve and changes in XRD patterns. Experiments were conducted to find the optimal combination of sintering temperature, sintering time, and boric acid dosage to produce an ALWA of favorable characteristics in terms of water absorption, bulk density, apparent porosity, compressive strength and weight loss to satisfy Taiwan's regulatory requirements for construction and insulation materials. Optimal results gave a sintering temperature of 850 degrees C for 15 min at a boric acid dosage of 15% by weight of SPS. Results for ALWA favorable characteristics were: 0.21% (water absorption), 0.35% (apparent porosity), 1.67 g/cm3 (bulk density), 66.94 MPa (compressive strength), and less than 0.1% (weight loss).

PWR steam-side chemistry follow program. Final report

International Nuclear Information System (INIS)

Economy, G.; Wootten, M.J.

1982-08-01

Denting is the diametral reduction of Inconel 600 tubes at the support plates of several nuclear steam generators during operation. This tube deformation was shown to be caused by the expansion forces resulting from formation of voluminous oxide generated by corrosion of the carbon steel support plate. The denting phenomenon and potential methods for its inhibition were investigated in the laboratory using isothermal capsules and heated crevice (heat transfer) testing at temperatures relevant to operating steam generators. Both test methods simulate the tube-support plate geometry and materials. Mathematical models were developed to predict the denting behavior of isothermal capsules. Three additives were investigated as potential denting inhibitors. Soaking with calcium hydroxide or sodium phosphate under heat transfer conditions did not inhibit denting when the environment was recontaminated, in contrast to similar soaks in boric acid which inhibited denting for two to four weeks following recontamination. When the boric acid soak was followed by on-line boric acid treatment, inhibition was maintained

Volume reduction by crystallization of low-level radioactive wastes

International Nuclear Information System (INIS)

Grant, D.C.; Murray, A.P.

1982-01-01

Low-level radioactive wastes containing boric acid, borax, or sodium sulfate, with radioactive contaminants, are generated during the operation of nuclear power plants. These wastes require disposal, and as such, it is economically and environmentally desirable to reduce their volume. Crystallization was examined in the laboratory as a means of accomplishing this. The crystallizer was operated in both of two modes: evaporative cooling and total evaporation. A 12 wt% boric acid waste feed was concentrated to a 40 to 45 wt% slurry in both modes of operation. Using pure boric acid, a slurry containing over 60 wt% was obtained. An 18.5 wt% borax waste feed was concentrated to 50 wt% in the total evaporative mode and 70 wt% in the evaporatively cooled mode. A 22 wt% sodium sulfate feed was concentrated to a 78 wt% slurry in the total evaporative mode. For all of the feeds, this represents a 4- to 5-fold volume reduction by the crystallizer

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)

Device for borating the primary circuit of a water-cooled nuclear reactor plant

International Nuclear Information System (INIS)

Stiefel, M.

1985-01-01

The extraction pipes for the boric acid and deionisation container are each connected to a pipe which can be shut off behind the pump. Measures for checking the contents of the container are provided in the extraction pipes and/or in the pipes leading to the containers. Faults can therefore be recognised in good time. The degree of availability is increased and the number of necessary redundant devices is reduced. The extraction pipe of the boric acid container has a rotary displacement pump. (HP) [de

Absorção e redistribuição de boro em coqueiro-anão-verde Boron absorption and redistribution in green dwarf coconut tree

Directory of Open Access Journals (Sweden)

Leandro Glaydson da Rocha Pinho

2008-12-01

Full Text Available O objetivo deste trabalho foi verificar se ocorre redistribuição de boro em coqueiros (Cocos nucifera, quando a aplicação de ácido bórico é realizada na axila foliar ou no solo. Foram empregados os seguintes tratamentos com ácido bórico: 30 g aplicados sobre a axila da folha número 10; 60 g aplicados ao solo; e controle, sem aplicação. Foram realizadas duas aplicações de B, com um intervalo de cinco meses entre elas. A unidade experimental consistiu de duas plantas, com seis repetições, em delineamento inteiramente casualizado. Foram determinados os teores de boro nas folhas 2, 6, 10, 14 e 18, aos dois e quatro meses após a primeira aplicação de ácido bórico, e aos dois e cinco meses após a segunda aplicação. O boro se redistribuiu pela planta de coqueiro, independentemente da forma de aplicação. A elevação do teor de boro nas folhas persistiu por mais tempo, quando a aplicação de ácido bórico foi feita ao solo. As doses de ácido bórico aplicadas não causaram fitotoxidade, mesmo quando a aplicaçãofoi repetida após um curto período.The aim of this work was to verify if boron redistribution occurs among the coconut palm (Cocos nucifera fronds, when boric acid is applied on frond axils or on soil. The treatments with boric acid were: 30 g applied on the axil of frond number 10; 60 g applied to the soil; and a control without boric acid application. The B applications were repeated after five-month interval. The experimental unit consisted of two plants, with six replicates, in a randomized complete block design. Boron contents were determined in fronds number 2, 6, 10, 14 and 18, two and four months after the first boric acid application, and two and five months after the second application. Boron was redistributed in coconut plants, regardless of the application form. Increases in boron concentration in fronds persisted longer when boric acid was applied to the soil. The applied doses of boric acid hadno

A basic study for the boron thermal regeneration system using anion exchange resins

International Nuclear Information System (INIS)

Frantiesek, P.; Kotaka, Masahiro; Okamoto, Makoto; Kakihana, Hidetake.

1979-01-01

For the boron thermal regeneration system (BTRS), the basic characteristics of commercial anion exchange resin have been investigated on the swelling characteristics, absorption, desorption and temperature coefficient of exchange capacity for boric acid. The equilibrium capacity increases as decrease of temperature and depends strongly on the degrees of cross linking having a maximum point at about 7% of DVB. The temperature coefficient of equilibrium capacity of boric acid is also a function of the concentration of external solution and of the cross linking having a maximum point around 7% of DVB. (author)

X-ray fluorescence analysis of lutetium oxide/oxalate for rare earth impurities

International Nuclear Information System (INIS)

Chandola, L.C.; Khanna, P.P.

1985-01-01

An X-ray fluorescence spectrometric method for the analysis of lutetium oxide is described. The sample in the oxalate form is mixed with boric acid binding material and pressed into a pellet over supporting pellet of boric acid. A Philips PW 1220 wavelength dispersive semiautomatic X-ray fluorescence spectrometer is used for the analysis. The minimum determination limit is 0.002 percent for Y, Er and Yb and 0.005 percent for Tm. Calculations for theoretical minimum detection limits and percent standard deviations at each concentration of the standard are carried out. (author)

Method of preventing criticality of fresh fuel assembly in storage facility

International Nuclear Information System (INIS)

Kawamura, Makoto.

1990-01-01

With an aim of improving the operation efficiency of a reactor, extention of the operation cycle by increasing U 235 enrichment degree of fuel uranium is planned. However, along with the increase of the enrichment degree of the fuel uranium, there occurs a problem of criticality upon fuel handling. Then, in the present invention, boric acid incorporating B-10 of great neutron absorption effect are packed with water soluble polymeric materials which are further packed with a fuel packing sheet, or the water soluble polymeric materials incorporating boric acids are packed with fuel packing sheets which are disposed to a fresh fuel assembly and stored in a store house as they are. The fuel packing sheet is a perforated sheet having a plurality of water intruding pores. Then, if water should intrude to the store house accidentally, the water soluble polymeric materials are dissolved, so that the intruded water is converted into aqueous boric acid easily and absorbs neutrons effectively to thereby attain the prevention of criticality. (T.M.)

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 ...

Membrane systems and their use in nuclear power plants. Treatment of primary coolant

Energy Technology Data Exchange (ETDEWEB)

Kus, Pavel; Bartova, Sarka; Skala, Martin; Vonkova, Katerina [Research Centre Rez, Husinec-Rez (Czech Republic). Technological Circuits Innovation Dept.; Zach, Vaclav; Kopa, Roman [CEZ a.s., Temelin (Czech Republic). Nuclear Power Plant Temelin

2016-03-15

In nuclear power plants, drained primary coolant containing boric acid is currently treated in the system of evaporators and by ion exchangers. Replacement of the system of evaporators by membrane system (MS) will result in lower operating cost mainly due to lower operation temperature. In membrane systems the feed primary coolant is separated into two output streams: retentate and permeate. Retentate stream consists of the concentrated boric acid solution together with other components, while permeate stream consists of purified water. Results are presented achieved by testing a pilot-plant unit of reverse osmosis in nuclear power plant (NPP) Temelin.

Neutronic-thermohydraulic oscillatory instability in modern PWRs due to high concentrations of boron in the water

International Nuclear Information System (INIS)

Novelli, A.

1985-01-01

Conspicuous amounts of boric acid are normally dissolved into the moderator of a modern PWR, especially in BOL operative conditions. If the concentration of such a neutronic poison attains certain limits, the nuclear temperature coefficient of the moderator, which is highly negative in the absence of boron, may turn about and reach positive values, due to the strong thermal expansion of the water. A dynamical model of a PWR system is presented, facilitating a quick stability analysis related to the co-ordination of boric acid solution in the water and control-rod insertion in the core. (author)

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

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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.

A study on the generation of radioactive corrosion product at PWR for extended fuel cycle

International Nuclear Information System (INIS)

Min Chul Song; Kun Jai Lee

2001-01-01

Current nuclear power plant operating practice is to extend the time between refueling from a 12 month operating cycle to an 18-24 month period. This current to longer fuel cycles has complicated the dilemma of finding optimum pH range for the primary coolant chemistry. The International Commission on Radiological Protection (ICRP) in ICRP publication No. 60 recommends optimization of operator radiation exposure (ORE) in nuclear power plants. CRUD formed in the plants is the major source of ORE and its transport mechanism is not understood. To analyze the generation of CRUD at the extended fuel cycle, the COTRAN code, which was developed at the Korea Advanced Institute of Science and Technology (KAIST), was used. It predicts that the activity of CRUD decreases as the pH of the coolant increases. For the same period of different fuel cycles, as the operating fuel cycle duration is increased, the generation of the CRUD increases. In this paper, enriched boric acid (40% enriched 10 B concentration) for reactivity control is adopted as the required chemical shim rather than natural boric acid. The effect of the enriched boric acid (EBA) is that the neutron absorption capability of the chemical shim is maintained while decreasing the required boron and lithium concentration in the reactor coolant system. By employing enriched boric acid, the amounts of CRUD generated are reduced, because the high pH-operating period is extended. From the waste generation point of view, more filters or ion exchangers to remove CRUD are required and the amounts of waste are increased at the extended fuel cycle. (author)

Flame retardant finishing of cotton fabric based on synergistic compounds containing boron and nitrogen.

Science.gov (United States)

Xie, Kongliang; Gao, Aiqin; Zhang, Yongsheng

2013-10-15

Boric acid and compound containing nitrogen, 2,4,6-tri[(2-hydroxy-3-trimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-HTAC) were used to finish cotton fabric. The flame retardant properties of the finished cotton fabrics and the synergetic effects of boron and nitrogen elements were investigated and evaluated by limited oxygen index (LOI) method. The mechanism of cross-linking reaction among cotton fiber, Tri-HTAC, and boric acid was discussed by FTIR and element analysis. The thermal stability and surface morphology of the finished cotton fabrics were investigated by thermogravimetric analysis (TGA) and scanning electron microscope (SEM), respectively. The finishing system of the mixture containing boron and nitrogen showed excellent synergistic flame retardancy for cotton fabric. The cotton fabric finished with mixture system had excellent flame retardancy. The LOI value of the treated cotton fabric increased over 27.5. Tri-HTAC could form covalent bonds with cellulose fiber and boric acid. The flame retardant cotton fabric showed a slight decrease in tensile strength and whiteness. The surface morphology of flame retardant cotton fiber was smooth. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ammonia volatilization from coated urea forms

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Carlos Antonio Costa do Nascimento

2013-08-01

Full Text Available Nitrogen fertilization is a major component of the cost of agricultural production, due to the high cost and low efficiency of fertilizers. In the case of urea, the low efficiency is mainly due to losses by volatilization, which are more pronounced in cultivation systems in which plant residues are left on the soil. The objective of this work was to compare the influence of urea coated with sulfur or boric acid and copper sulfate with conventional N fertilizers on N volatilization losses in sugar cane harvested after stubble burning. The sources urea, sulfur-coated urea, urea coated with boric acid and copper sulfate, as well as nitrate and ammonium sulfate, were tested at amounts containing N rates of 120 kg ha-1 N. The integration of new technologies in urea fertilization can reduce N losses by volatilization. These losses were most reduced when using nitrate and ammonium sulfate. The application of a readily acidified substance (boric acid to urea was more efficient in reducing volatilization losses and nutrient removal by sugar cane than that of a substance with gradual acidification (elemental sulfur.

Contamination of the ground waters and surface waters by boron in Lerma Valley, NW-Argentina - an inventory

International Nuclear Information System (INIS)

Bundschuh, J.

1992-01-01

Ground- and surface waters in areas unaffected by pollution from borax and boric acid producing plants exhibit low boron concentrations of less than 300 μg B/l. Only at the boric acid plant 'Mineratea' is the groundwater contaminated, with up to 6200 μg B/l occurring within an area of 8 to 10 km 2 with more than 1000 μg boron/l. Even higher boron concentrations (up to 18 μg B/l) are present in polluted surface waters. Not the boron concentration in the irrigation water, but the absolute amount of boron added to the plants by irrigation is what determines plant toxicity. For the contaminated area of the boric acid 'Mineratea', characterized by boron concentrations of between 1000 and 6000 μg B/l, the maximal amounts of irrigation water that can be applied lies between 300 and 8 mm. In order to protect the local groundwater resoures from present and future contamination, environmental impact assessment on industrial projects in the area are required. In this way, the quality of the drinking and irrigation water can be guaranteed through suitable measures, without hindering further necessary industrial development of the region. (orig./UWA) [de

Leaching of nuclear power reactor waste forms

International Nuclear Information System (INIS)

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

1987-01-01

The leaching tests for immobilized power reactor wastes carried out at IPEN are described. These wastes 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. Three years leaching results are reported. The cesium diffuvity coefficients determined out of these results are about 1 x 10 -8 cm 2 /s for boric acid waste form and 9 x 10 -9 cm 2 /s for ion-exchange resin waste. Strontium diffusivity coefficients found are about 3 x 10 -11 cm 2 /s and 9 x 10 -11 cm 2 /s respectively. (Author) [pt

The development of radioactive waste treatment technology(IV)

International Nuclear Information System (INIS)

Kim, Joon Hyung; Yim, Sung Paal; Lee, Kune Woo; Yoo, Jeong Woo; Kim, Young Min; Park, Seong Chul

1992-03-01

Following studies were performed in the project of development of radioactive waste treatment technology. 1) Treatment of radioactive borated liquid wastes by reverse osmosis : Separation characteristics of boric acid were estimated using cellulose acetate membrane and aromatic polyamide membrane. The performance of reverse osmosis process was evaluated in terms of boric acid recovery, radiochemical rejection, and membrane flux by operating variables such as applied pressure and feed concentration. 2) Oily waste treatment : The mathematical model to estimate oil removal efficiency is to be proposed at coalescence column. 3) Treatment of radioactive laundry waste 4) Comparison of evaporation and ion-exchange 5) State of the art of high integrity container. (Author)

X-ray fluorescence analysis of thulium oxide/oxalate for rare earth impurities

International Nuclear Information System (INIS)

Chandola, L.C.; Khanna, P.P.

1986-01-01

An X-ray fluorescence spectrometric method for the analysis of thulium oxide is described. For the analysis, the sample in oxalate form is mixed with boric acid binding material and pressed into a pellet over a supporting pellet of boric acid. A wavelength dispersive Philips PW 1220 X-ray fluorescence spectrometer is used for the experiments; the minimum determination limits are 0.002per cent for Ho, Lu and Y, 0.005per cent for Dy and Er and 0.01per cent for Yb. Calculations for theoretical minimum detection limits and percent standard deviation at each concentration of the standard are carried out. (author)

The effects of different additives in electrolyte of AGM batteries on self-discharge

Energy Technology Data Exchange (ETDEWEB)

Yazd, M. Safari; Molazemi, A. [Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 91775-1111 (Iran); Moayed, M.H. [Metallurgical and Materials Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, P.O. Box 91775-1111 (Iran)

2006-07-14

Hydrogen and oxygen evolution at the negative and positive electrodes in AGM batteries are the main reasons of self-discharging. The self-discharge of five AGM batteries was investigated by measuring different potential between two electrodes during 48 days. Five different battery electrolytes were used including 35% (w/w) H{sub 2}SO{sub 4} without additives and the remaining contain 7.1, 9.94, and 21.3gl{sup -1} sodium sulfate, 4gl{sup -1} boric acid, 3gl{sup -1} citric acid, and finally 0.7 and 1gl{sup -1} stearic acid except one containing boric acid that the concentration of H{sub 2}SO{sub 4} was 36% (w/w). The results revealed that the rate of self-discharge for battery without additive was 0.01Vday{sup -1}. The battery with boric acid showed the lowest rate of self-discharge with 0.0025Vday{sup -1}. It was also found that stearic and citric acids are comparatively appropriate additives for decreasing the self-discharge. They caused a decrease of the self-discharge rate to 0.005 and 0.0075Vday{sup -1} on appropriate concentration, respectively. In compared to other additives, sodium sulfate showed to be not an appropriate additive for decreasing battery self-discharging. The rate of 0.03Vday{sup -1} of self-discharging was obtained for the battery containing all selected concentration of sodium sulfate during first 4 days of measuring. (author)

Determination of boron in sea water by atomic absorption spectrophotometry

International Nuclear Information System (INIS)

Horta, A.M.T.C.; Curtius, A.J.

1978-01-01

The chelation-extraction of boric acid with are acid solution of 2-ethyl-1,3 hexanediol in methy1-isobutye-ketone is studied. By this way a simple, quick and precise method for boron determination can be obtained [pt

Synthesis and characterization of boron trifluoride (B F[sub 3]). Sintese e caracterizacao de trifluoreto de boro (BF[sub 3])

Energy Technology Data Exchange (ETDEWEB)

Bastos, E T.R.; Umeda, K; Echternacht, M V; Silva, E.F. da.

1994-08-01

High purity boron trifluoride (B F[sub 3]) has been prepared from reaction of ammonium fluorborate and boron oxide in concentrated sulfuric acid. Fluorborate was synthesized by reaction of ammonium bi fluoride and boric acid produced from enrichment plant. (author).

Loss of ammonia from nitrogen fertilizers applied to maize and soybean straw

Directory of Open Access Journals (Sweden)

Letícia de Abreu Faria

2013-08-01

Full Text Available In Brazilian agriculture, urea is the most commonly used nitrogen (N source, in spite of having the disadvantage of losing considerable amounts of N by ammonia-N volatilization. The objectives of this study were to evaluate: N lossby ammonia volatilization from: [urea coated with copper sulfate and boric acid], [urea coated with zeolite], [urea+ammonium sulfate], [urea coated with copper sulfate and boric acid+ammonium sulfate], [common urea] and [ammonium nitrate]; and the effect of these N source son the maize yield in terms of amount and quality. The treatments were applied to the surface of a soil under no-tillage maize, in two growing seasons. The first season (2009/2010 was after a maize crop (maize straw left on the soil surface and the second cycle (2012/2011 after a soybean crop. Due to the weather conditions during the experiments, the volatilization of ammonia-N was highest in the first four days after application of the N sources. Of all urea sources, under volatilization-favorable conditions, the loss of ammonia from urea coated with copper sulfate and boric acid was lowest, while under high rainfall, the losses from the different urea sources was similar, i.e., an adequate rainfall was favorablet o reduce volatilization. The ammonia volatilization losses were greatest in the first four days after application. Maize grain yield differed due to N application and in the treatments, but this was only observed with cultivation of maize crop residues in 2009/2010. The combination of ammonium+urea coated with copper sulfate and boric acid optimized grain yield compared to the other urea treatments. The crude protein concentration in maize was not influenced by the technologies of urea coating.

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

Science.gov (United States)

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

2015-01-01

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

Determination of very small contents of boron by pH difference measurement

International Nuclear Information System (INIS)

Boehm, H.; Kirmse, E.M.; Schilbach, U.

1983-01-01

For the determination of boron as a trace element for food of plants in a very complicated salt matrix an analytical proceeding was developed, which allows to determine the content of boron without separation. The principle of analysis is based on the esterification of boric acid with a multivalent alcohol, which leeds to a monovalent strong complex acid. The change of the pH value of the analysing solution is measured. From the initial pH number, the end pH number, the volume of the analysing solution and the ionic product of water corresponding with the operating temperature the quantity of boric acid of boron that is equivalent the produced quantity of H + -ions is calculated by means of a linear program. The standard deviation of analytical proceeding amounts to 13.9 ng B. For the determination of the contents of boron of an unknown sample, five to ten separate measurements are carried out. For solutions, which are about 1x10 -6 M of boric acid, there are necessary 10 ml of sample for each separate measurement. The confidence interval of analytical results is found to be between +- 0.5 and +- 15.5% (P=0.99). For the determination of the content of boron in plant materials about 50-100 mg of dry weight are necessary. (Author)

Enhancement of virulence of bacillus thuringiensis and serratia marcescens by chemicals

International Nuclear Information System (INIS)

Khan, K. A.

2006-01-01

Studies were conducted on the enhancement of pathogenicity of Bacillus thuringiensis by 1% boric acid against various species of termites. The increase in virulence of Serratia marcescens by 1% potassium chloride or 1% Sodium citrate against the workers of M. championi has also been established. The increase in virulence is confirmed by the enhancement ratio, which are ranging from about 1.5 to 1.8 for Bacillus thuringiensis and 1.3 to 1.6 for Serratia marcescens. It was also noted that 1% boric acid alone was found toxic to various species of termites. However, Potassium chloride and Sodium citrate in a concentration of 1% were non-toxic to the workers of M. championi. (author)

Determination of Ti, Cr, Cu and Ta in niobium oxide by X-ray fluorescence method

International Nuclear Information System (INIS)

Dixit, R.M.; Deshpande, S.S.

1986-01-01

An x-ray fluorescence method for the determination of Ti, Cr, Cu and Ta in niobium oxide has been developed. Samples/standards in powder form are mixed with boric acid in the proportion of 1:1 (400 mg. each). Double layer pellets are prepared by pressing this mixture over a primary boric acid pellet. Philips PW-1220, a semiautomatic x-ray spectrometer with tungsten target x-ray tube for excitation and LiF (200) crystal for dispersion have been used. The determination range is from 0.005 to 0.1per cent for Ti and Cr, 0.01 to 0.1per cent for Cu and 0.05 to 1per cent for Ta. (author)

Coolant circuit water chemistry of the Paks Nuclear Power Plant

International Nuclear Information System (INIS)

Tilky, Peter; Doma, Arpad

1985-01-01

The numerous advantages of the proper selection of water chemistry parameters including low corrosion rate of the structural materials, hence the low-level activity build-up, depositions, radiation doses were emphasized. Major characteristics of water chemistry applied to the primary coolant of pressurized water reactors including neutral, slightly basic and strong basic ones are discussed. Boric acid is widely used to control reactivity. Primary coolant water chemistry of WWER type reactors which is based on the addition of ammonia and potassium hydroxide to boric acid is compared with that of other reactors. The demineralization of the total condensate of the steam turbines became a general trend in the water chemistry of the secondary coolant circuits. (V.N.)

Insights into the Mechanisms Underlying Boron Homeostasis in Plants

Directory of Open Access Journals (Sweden)

Akira Yoshinari

2017-11-01

Full Text Available Boron is an essential element for plants but is toxic in excess. Therefore, plants must adapt to both limiting and excess boron conditions for normal growth. Boron transport in plants is primarily based on three transport mechanisms across the plasma membrane: passive diffusion of boric acid, facilitated diffusion of boric acid via channels, and export of borate anion via transporters. Under boron -limiting conditions, boric acid channels and borate exporters function in the uptake and translocation of boron to support growth of various plant species. In Arabidopsis thaliana, NIP5;1 and BOR1 are located in the plasma membrane and polarized toward soil and stele, respectively, in various root cells, for efficient transport of boron from the soil to the stele. Importantly, sufficient levels of boron induce downregulation of NIP5;1 and BOR1 through mRNA degradation and proteolysis through endocytosis, respectively. In addition, borate exporters, such as Arabidopsis BOR4 and barley Bot1, function in boron exclusion from tissues and cells under conditions of excess boron. Thus, plants actively regulate intracellular localization and abundance of transport proteins to maintain boron homeostasis. In this review, the physiological roles and regulatory mechanisms of intracellular localization and abundance of boron transport proteins are discussed.

Effect of Relative Humidity on the Tribological Properties of Self-Lubricating H3BO3 Films Formed on the Surface of Steel Suitable for Biomedical Applications

Directory of Open Access Journals (Sweden)

E. Hernández-Sanchez

2015-01-01

Full Text Available The effect of environmental humidity on the self-lubricating properties of a thin film of boric acid (H3BO3 was evaluated. H3BO4 films were successfully formed on the surface of AISI 316L steel. The study was conducted on AISI 316L steel because of its use in biomedical applications. First, the samples were exposed to boriding to generate a continuous surface layer of iron borides. The samples were then exposed to a short annealing process (SAP at 1023 K for 5 min and cooled to room temperature while controlling the relative humidity (RH. Five different RH conditions were tested. The purpose of SAP was to promote the formation of a surface film of boric acid from the boron atoms present in the iron boride layers. The presence of the boric acid at the surface of the borided layer was confirmed by Raman spectroscopy and X-ray diffraction (XRD. The self-lubricating capability of the films was demonstrated using the pin-on-disk technique. The influence of RH was reflected by the friction coefficient (FC, as the samples cooled with 20% of RH exhibited FC values of 0.16, whereas the samples cooled at 60% RH showed FC values of 0.02.

Borate compound content reduction in liquid radioactive waste from nuclear power plants with VVER reactor

International Nuclear Information System (INIS)

Szalo, A.; Zatkulak, M.

2000-01-01

This paper describes the current status of liquid waste (evaporator concentrates) inventory at V-1 and V-2 NPPs in Jaslovske Bohunice and the intention to separate boron from them with respect to waste minimisation and improvement of physical and chemical properties for further waste treatment and conditioning. Preliminary results of laboratory experiments concerned to borate crystallisation after pH adjustment with nitric or formic acid performed in the 1998 are given. At the present time laboratory experiments continuing - next acids, coagulation with carbon oxide, electrolytic process, ion exchange resin, study of decontamination factors, immobilization of boric acid, decrease radioactivity, purification of boron-contained compounds. Slovenske Elektrarne have accumulated 7,000 m 3 of evaporator concentrates containing 100-180 g/l borate. In order to make more storage space available, it is proposed to remove some of the borate in the liquor by precipitation as sodium tetraborate and immobilise in either cement of bitumen. The supernate can be further volume reduced by evaporation and returned to the tanks. Slovenske Elektrarne are currently evaluating acid addition to the pH 12-13 concentrate to reduce the borate solubility. However, this adds to the salt burden of the waste through this chemical addition -thus creating future increases in conditioning and disposal costs. Boric acid is used in pressurized water as a soluble neutron poison to control reactivity and also to assure a safety margin in the spent fuel pool and during refuelling operations. Boric acid is also present in the water reserved for injection into the reactor in the event of postulated accidents. (author)

The preservation of urine samples for determination of renal stone risk factors

Science.gov (United States)

Nicar, M. J.; Hsu, M. C.; Johnson, T.; Pak, C. Y.

1987-01-01

A preservation technique for urine specimens before determination of stone risk factors was evaluated. The purpose of these experiments was to prove the effectiveness of the preservatives used to prevent changes in the concentrations of those constituents measured. Measured concentrations in fresh specimens were compared with those in the same specimens after storage with the preservatives. Refrigeration at 4 degrees C up to five days was appropriate in a laboratory setting, as no significant changes in urinary concentrations occurred. Refrigeration, however, did not offer a convenient method for shipping. Chemical preservation was found to be an effective alternative to refrigeration. Thymol prevented changes in concentration of pH, citrate, uric acid, sulfate, sodium, potassium, and cyclic AMP, while a mixture of hydrochloric (HCl) acid and boric acid prevented changes in calcium, magnesium, phosphorus, oxalate, ammonium, and creatinine. Thus, the addition of thymol or HCl/boric acid to urine specimens will prevent significant changes in the concentrations of stone risk factors.

Influence of water chemistry on IGSCC growth rate of SUS316 under high temperature water

International Nuclear Information System (INIS)

Fukumura, Takuya; Terachi, Takumi; Arioka, Koji

2005-01-01

The influence of the environment on intergranular stress corrosion crack behavior was examined by performing tensile tests in high-temperature water using cold-water non-sensitized 316 stainless steel. In the constant elongation test, the crack growth rate showed a clear environmental dependence on the concentration of dissolved hydrogen, boric acid and lithium, but no such environmental dependence was observed in the compact tension test. Regarding the influence of the environment on the intergranular stress corrosion crack behavior of non-sensitized 316 stainless steel, it is considered that the environmental factors of dissolved hydrogen (3-45 cc/kgH 2 O), boric acid (500-3500 ppm) and lithium (0.05-10 ppm) greatly affect the initiation process but do not significantly affect the propagation process. (author)

Electrochemical measurements in PWR steam generators to follow crevice chemistry

International Nuclear Information System (INIS)

Feron, D.

1991-01-01

In PWR steam generator crevices, the evolution of chemistry is important for the understanding of corrosion phenomena. Electrochemical measurements have been performed in high temperature simulated crevice environments in order to follow hideout processes and remedial actions (on-line addition of boric acid). Reported tests have been conducted with model boilers of AJAX facilities. Eccentric and concentric tube support plate crevices have been instrumented with platinum electrodes. Electrochemical measurements have been collected when model boiler was under nominal conditions (primary temperature: 335 deg C, secondary temperature: 280 deg C). They include Electrochemical Impedance Spectroscopy (EIS) and potential measurements: with EIS, sodium and boric acid hideouts have been detected and followed. Potential measurements have been performed in an attempt to measure crevice PH evolution

Prediction of Layer Thickness in Molten Borax Bath with Genetic Evolutionary Programming

Science.gov (United States)

Taylan, Fatih

2011-04-01

In this study, the vanadium carbide coating in molten borax bath process is modeled by evolutionary genetic programming (GEP) with bath composition (borax percentage, ferro vanadium (Fe-V) percentage, boric acid percentage), bath temperature, immersion time, and layer thickness data. Five inputs and one output data exist in the model. The percentage of borax, Fe-V, and boric acid, temperature, and immersion time parameters are used as input data and the layer thickness value is used as output data. For selected bath components, immersion time, and temperature variables, the layer thicknesses are derived from the mathematical expression. The results of the mathematical expressions are compared to that of experimental data; it is determined that the derived mathematical expression has an accuracy of 89%.

Reproductive toxicity in boron exposed workers in Bandirma, Turkey.

Science.gov (United States)

Başaran, Nurşen; Duydu, Yalçin; Bolt, Hermann M

2012-06-01

Boric acid and sodium borates have been considered as being "toxic to reproduction and development", following results of animal studies with high doses. However unfavorable effects of boron exposure on reproduction and development have not been proved in epidemiological studies so far. The aim of the present study was to investigate the reproductive toxicity indicators in highly exposed workers employed in a boric acid production plant in Bandırma, Turkey. Two hundred and four workers participated in this study. The mean blood boron concentration of the high exposure group of workers was 223.89 ± 69.49 (152.82-454.02)ng/g. Unfavorable effects of boron exposure on the reproductive toxicity indicators were not observed. Copyright © 2012 Elsevier GmbH. All rights reserved.

Effects of impregnation with boron compounds on the surface ...

African Journals Online (AJOL)

Liebl.) which met the requirements of ASTM D 358 were impregnated according to ASTM D 1413 with boric acid (Ba) and borax (Bx) by vacuum technique. After impregnation, surfaces were coated with cellulosic, synthetic, polyurathane, water-based, acrylic and acid hardening varnishes in accordance with ASTM D 3023 ...

Thermal-hydraulic studies on the safety of VVER-440 type nuclear power plants

International Nuclear Information System (INIS)

Tuunanen, J.

1994-01-01

The thesis includes several thermal-hydraulic analyses related to the Loviisa VVER-440 nuclear power plant units. The work consists of experimental studies, analysis of the experiments, analysis of some plant transients and development of a calculational model for calculation of boric concentrations in the reactor. In the first part of thesis, in the case of simulation of boric acid solution behaviour during long-term cooling period of LOCAs, experiments were performed in scaled-down test facilities. The experimental data together with the results of RELAP5/MOD3 simulations were used to develop a model for calculations of boric acid concentrations in the reactor during LOCAs. In the second part, in the case of simulation of horizontal generators, experiments were performed with PACTEL integral test loop to simulate loss of feedwater transients. The PACTEL experiments as well as earlier REWETT-III natural circulation tests, were analyzed with RELAP5/MOD3 Version 5m5 code. The third part of the work consists of simulations of Loviisa VVER reactor pump trip transients with RELAP5/MOD1-Eur, RELAP5/MOD3 and CATHARE codes. (56 refs., 9 figs.)

Theory of Ion and Water Transport in Reverse-Osmosis Membranes

Science.gov (United States)

Oren, Y. S.; Biesheuvel, P. M.

2018-02-01

We present a theory for ion and water transport through reverse-osmosis (RO) membranes based on a Maxwell-Stefan framework combined with hydrodynamic theory for the reduced motion of particles in thin pores. We take into account all driving forces and frictions both on the fluid (water) and on the ions including ion-fluid friction and ion-wall friction. By including the acid-base characteristic of the carbonic acid system, the boric acid system, H3O+/OH- , and the membrane charge, we locally determine p H , the effective charge of the membrane, and the dissociation degree of carbonic acid and boric acid. We present calculation results for an experiment with fixed feed concentration, where effluent composition is a self-consistent function of fluxes through the membrane. A comparison with experimental results from literature for fluid flow vs pressure, and for salt and boron rejection, shows that our theory agrees very well with the available data. Our model is based on realistic assumptions for the effective size of the ions and makes use of a typical pore size of a commercial RO membrane.

Impact of reactor water chemistry on cladding performance

Energy Technology Data Exchange (ETDEWEB)

Cox, B. [University of Toronto, Centre for Nuclear Engineering, Toronto, Ontario (Canada)

1997-07-01

Water chemistry may have a major impact on fuel cladding performance in PWRs. If the saturation temperature on the surface of fuel cladding is exceeded, either because of the thermal hydraulics of the system, or because of crud deposition, then LiOH concentration can occur within thick porous oxide films on the cladding. This can degrade the protective film and accelerate the corrosion rate of the cladding. If sufficient boric acid is also present in the coolant then these effects may be mitigated. This is normally the case through most of any reactor fuel cycle. Extensive surface boiling may disrupt this equilibrium because of the volatility of boric acid in steam. Under such conditions severe cladding corrosion can ensue. The potential for such effects on high burnup cladding in CANDU reactors, where bone acid is not present in the primary coolant, is discussed. (author)

Impact of reactor water chemistry on cladding performance

International Nuclear Information System (INIS)

Cox, B.

1997-01-01

Water chemistry may have a major impact on fuel cladding performance in PWRs. If the saturation temperature on the surface of fuel cladding is exceeded, either because of the thermal hydraulics of the system, or because of crud deposition, then LiOH concentration can occur within thick porous oxide films on the cladding. This can degrade the protective film and accelerate the corrosion rate of the cladding. If sufficient boric acid is also present in the coolant then these effects may be mitigated. This is normally the case through most of any reactor fuel cycle. Extensive surface boiling may disrupt this equilibrium because of the volatility of boric acid in steam. Under such conditions severe cladding corrosion can ensue. The potential for such effects on high burnup cladding in CANDU reactors, where bone acid is not present in the primary coolant, is discussed. (author)

Fate and behavior of an organo-borate in the soil-plant system

International Nuclear Information System (INIS)

Adriano, D.C.; Mills, G.L.; Afre, J.L.; Hart, R.J.

1984-01-01

An organo-borate, sodium tetraphenylboron (NaTPB), is used to precipitate radiocesium in high level nuclear wastes in conjunction with the 'glassification' of these wastes for long-term storage. Because of the possibility of this compound interacting with the environment through land application of the waste supernate or ground burial of the waste 'saltblocks', studies were undertaken to evaluate the environmental chemistry of this compound. Results indicate that the parent compound, NaTPB, is unstable in the soil-plant system, yielding two primary degradation products, biphenyl and diphenylborinic acid. Plant growth and B uptake data further indicate that the growth of plants was more deleteriously affected by NaTPB soil treatment than by comparable soil treatment with boric acid, in spite of the much greater uptake of B from boric acid. This can be attributed to the hypothesized aggravating effect of biphenyl on plant growth. (author)

WEED CONTROL AND BORON NUTRITION ON Eucalyptus IN SILVOPASTORAL SYSTEM

Directory of Open Access Journals (Sweden)

Alexandre Magno Brighenti

2015-04-01

Full Text Available The objective of this study was to evaluate the control of weeds in the rows of eucalyptus (Eucalyptus urograndis with herbicides applied singly or combined with boron (B, as well as, the response of Eucalyptus plants to this micronutrient. The experiments were carried out in a split-plot with randomized complete block design, with three replicates. Six treatments were applied to the plots: (i weeded control, (ii control without weeding, (iii glyphosate (1080 g ae ha-1 + chlorimuron-ethyl (10 g ai ha-1 + 0.05% v / v mineral oil, (iv glyphosate (1080 g ae  ha-1 + isoxaflutole (112.5 g ai ha-1,  (v glyphosate (1080 g ae ha-1 and  (vi oxyfluorfen (480 g ai ha-1. The sub-plots consisted of the absence or presence of 4 kg of boric acid (H3BO3 - 17% B in 100 L of water. The addition of boric acid in the solution containing the herbicides did not affect the weed control. There was an increase in boron content in the soil and consequently an increase in the boron levels in the eucalyptus leaves. The combined application of herbicides plus boric acid is perfectly suitable for preventing dry of the pointer on eucalyptus plants. Keywords: Eucalyptus urograndis; chemical control; herbicides; micronutrients; Urochloa decumbens.

Discriminative power of an assay for automated in vitro screening of teratogens

DEFF Research Database (Denmark)

Walmod, Peter S; Gravemann, Ute; Nau, Heinz

2004-01-01

-trans-retinoic acid, pentyl-4-yn-valproic acid, saccharin, salicylic acid and valproic acid. All compounds, with the exception of dimethadione inhibited proliferation in a linear dose-dependent manner, and there were statistically significant compound class-dependent differences between the IC(50)-values...... to teratogenicity were: 5-bromo-2(')-deoxyuridine, 6-aminonicotinamide, acrylamide, boric acid, D-(+)-camphor, dimethadione, dimethyl phthalate, diphenhydramine, hydroxyurea, isobutyl-ethyl-valproic acid, lithium chloride, methyl mercury chloride, methotrexate, methoxyacetic acid, penicillin G, all...

X-ray fluorescence analysis of terbium oxide for rare earth impurities

International Nuclear Information System (INIS)

Chandola, L.C.; Machado, I.J.; Mohile, A.N.

1975-01-01

A method for the determination of Sm 2 O 3 , Eu 2 O 3 , Gd 2 O 3 , Dy 2 O 3 , Ho 2 O 3 and Y 2 O 3 in terbium oxide is described. The sample is converted to terbium oxalate, mixed with boric acid binder in the ratio 2:1, pelleted at a pressure of 20 tons over a boric acid backing pellet and irradiated with x-rays from a tungsten tube operated by Philips PW 1140 generator. The secondary x-rays thus generated are analysed by a LiF (200) crystal in Philips PW 1220 x-ray fluorescence spectrometer using suitable detectors. The minimum determination limit (MDL) is 0.01% for all rare earth oxides determined except for Y 2 O 3 for which it is 0.005%. (author)

Development and evaluation of polyethylene as solidification agent for low-level waste

International Nuclear Information System (INIS)

Franz, E.M.; Colombo, P.

1986-09-01

A polyethylene solidification process, using an extrusion system, has been developed for the immobilization of dry wastes resulting from volume reduction technologies. Ease of processibility and high packing efficiencies were obtained through the use of low-density polyethylene (0.917 to 0.924 g/cm 3 ) with melt indices from 2.0 to 55.0 g/10 min. Maximum waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash and 65 wt % ion exchnge were obtained. A series of tsts were conducted to assess the acceptability of polyethylene waste forms to meet the requirements of 10 CFR 61. Based on test results and process control considerations, optimal waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash and 30 wt % ion exchange resins are recommended

Material and water chemistry for a ferritic reactor coolant system in pressure water reactors

International Nuclear Information System (INIS)

Stieding, L.

1979-04-01

The use of unplated, low-alloy steels in a boric acid controlled PWR is not considered possible without changing the water conditions during the start-up and shut-down periods of the reactor. The significant pH reduction of the water due to boric acid during these periods most probably leads to damage of the magnetite protective layers followed by selective corrosion. As this highly important process has not been sufficiently evaluated with respect to our specific application problem, more detailed information will be necessary. KWU test facilities provide a means of performing such tests. In order to avoid corrosion attack during the above operating conditions, an inhibition of the water with 7 Li-borate is recommended which, however, will amount to approx. DM 60.000,-- per period of use. (orig.) [de

Effects of Treatment Materials on the Physical Properties of Eucalyptus (Eucalyptus camaldulensis Dehn. Wood

Directory of Open Access Journals (Sweden)

Selahattin Bardak

2011-04-01

Full Text Available This study was designed to determine effects on retention and shrink levels of Eucalyptus (Eucalyptus camaldulensis Dehn. which treated with some commercial preservative types, borates, polyethylene glycol, and water repellents. In this study, four type impregnation chemicals were chosen: 1. Commercial preservative types, [Ammonium sulphate, Vacsol-WR WR and Immersol-WR (WR], 2. Borates chemicals, [Boric acid, Borax, Boric acid+ Borax] 3. Polyethylene glycol such as Polyethylene glycol (PEG-400 4. Water repellents [Styrene, Methylmetacrylate.]. As a result, retention % and shrink levels of Eucalyptus wood was lower treated with commercial preservative types and borates preservatives compare to other treatment chemicals. However, retention % levels of Eucalyptus wood treated with WR chemicals were highly significant levels. According to their leachability period although PEG 400 showed antishrink effectiveness other treatments didnt showed antishrink efficiency.

Studies of light water lattices by the homogeneous boron poisoning technique

International Nuclear Information System (INIS)

Bailly, J.; Calament, J.; Girard, Y.; Golinelli, C.

1964-01-01

By homogeneously poisoning a critical facility with boric acid, one can balance important reactivities. Furthermore this technique is particularly interesting, due to the fact that it allows the substitution of cross sections to kinetic parameters in lattice calculations. With this use of boric acid as a poison arise important technological problems which are described in this report, the last part of which deals with the accuracy of the measurements made in these conditions. The main features of a lattice study made according to this moderator poisoning technique concern the determination of the concentration of dissolved boron which makes the multiplying assembly just critical and the determination of the reactivity factor as a function of temperature (this study has been carried out fill above 95 deg. C). (authors) [fr

The impact of the MCU life extension solvent on sludge batch 8 projected operating windows

International Nuclear Information System (INIS)

Peeler, D.K.; Edwards, T.B.

2013-01-01

As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NGS) and a new strip acid will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing or evaluations with the next generation solvent are required to determine the impact of these changes (if any) to Chemical Process Cell (CPC) activities, glass formulation strategies, and melter operations at the Defense Waste Processing Facility (DWPF). The introduction of the dilute (0.01 M) boric acid stream into the DWPF flowsheet has a potential impact on glass formulation and frit development efforts since B203 is a major oxide in frits developed for DWPF. Prior knowledge of this stream can be accounted for during frit development efforts but that was not the case for Sludge Batch 8 (SB8). Frit 803 has already been recommended and procured for SB8 processing; altering the frit to account for the incoming boron from the strip effluent (SE) is not an option for SB8. Therefore, the operational robustness of Frit 803 to the introduction of SE including its compositional tolerances (i.e., up to 0.0125M boric acid) is of interest and was the focus of this study. The primary question to be addressed in the current study was: What is the impact (if any) on the projected operating windows for the Frit 803 - SB8 flowsheet to additions of B203 from the SE in the Sludge Receipt and Adjustment Tank (SRAT)? More specifically, will Frit 803 be robust to the potential compositional changes occurring in the SRAT due to sludge variation, varying additions of ARP and/or the introduction of SE by providing access to waste loadings (WLs) of interest to DWPF? The Measurement Acceptability Region (MAR) results indicate there is very little, if any, impact on the projected operating windows for the Frit 803 - SB8 system regardless of the presence or absence of

Contributions te the study of methods and factors affecting the spectrophotometric determination of boron traces with carmin uranium compounds

International Nuclear Information System (INIS)

Fernandez Cellini, R.; Gasco Sanchez, L.

1956-01-01

The study of some factors affecting the spectrophotometric determination of boron traces with carmin is made; the influence of carmin from different origin, the stability of complex carmin-boric acid in relation with the sulphuric acid concentration, the interference produced by ion nitrate, and the ion uraline and light influence are discussed. (Author) 36 refs

Contributions te the study of methods and factors affecting the spectrophotometric determination of boron traces with carmin uranium compounds; Contribucion al estudio del metodo y factores que afectan a la determinacion espectrofotometrica de trazas de boro con Carmin en compuestos de uranio

Energy Technology Data Exchange (ETDEWEB)

Fernandez Cellini, R; Gasco Sanchez, L

1956-07-01

The study of some factors affecting the spectrophotometric determination of boron traces with carmin is made; the influence of carmin from different origin, the stability of complex carmin-boric acid in relation with the sulphuric acid concentration, the interference produced by ion nitrate, and the ion uraline and light influence are discussed. (Author) 36 refs.

Download this PDF file

African Journals Online (AJOL)

made visible by ethidium bromide. The results from gel electrophoresis were visualized on a UV transillumination. (254 nm). Agarose gel preparation as well as electrophoresis were carried out using buffer solution (pH 8.0), contain- ing 45 mmol/L Tris-base/boric acid and. 1 mmol/L EDTA adjusted with hydro- chloric acid.

Cobalt (II)–EDTA complex as a new reductant for phosphomolybdic ...

Indian Academy of Sciences (India)

Unknown

Trazodone; phosphomolybdic acid; cobalt nitrate; ethylenediamine tetra ... Aliquots of standard TZ solution (0⋅5–2⋅5 ml, 200 µg/ml in 0⋅01 M HCl) were ... 750 nm; εmax, 5⋅39 × 103 l mol–1 cm–1) was obtained after one hour if the reaction mixture ... starch (150-fold), boric acid (150-fold), stearic acid (70-fold), magnesium ...

Operational Environmental Assessment

Science.gov (United States)

1988-09-01

Anhydride 0 oz Cupric Sulfide 5 lb Oxalic Acid 56 oz Potassium Carbonate Anhydrous 32 oz Potassium Phosphate 36 oz Sodium Acetate 44 oz Sodium...Benzene 35,500 ml Antimony Potassium Tartrate 4,000 gm Barbituric Acid 150 gm Barbituric Acid 400 gm Chromium Trioxide 6,000 gm Disodium Ethylenediamine...Hydrocholoride 600 gm *Benzene a pt Boric Acid 5,000 gm Calcium Chloride 6,500 gm Calcium Chloride 3 lb Citric Acid 3 lb Citric Acid 2,500 gm Cupric Sulfate 2,500

IGA/SCC propagation rate measurements on alloy 600 steam generator tubing using a side stream model boiler

International Nuclear Information System (INIS)

Takamatsu, H.; Matsueda, K.; Matsunaga, T.; Kitera, T.; Arioka, K.; Tsuruta, T.; Okamoto, S.

1993-01-01

IGA/SCC crack propagation rate measurements using various types of IGA/SCC predefected ALloy 600 tubing were tested in model boilers, a side stream model boiler at Ohi Unit 1 and similar model boilers in the laboratory. Types of IGA/SCC predefects introduced from the outside of the tubing were as follows. (1) Actual IGA/SCC predefect introduced by high temperature caustic environments; (2) Longitudinal predefect by electrodischarge machining (EDM) method, and then crack tip fatigue was introduced to serve as the marker on the fractured surface (EDM slit + fatigue). IGA/SCC crack propagation rate was measured after the destructive examination by Cr concentration profile on fracture surface for (1), and observation of intergranular fractured surface propagated from the marked fatigue was employed for (2) and (3) after the model boiler tests. As for the water chemistry conditions, mainly AVT (high N 2 H 4 ) + boric acid (5-10ppm as B in SGs) treatment for both model boilers, and some of the tests for the model boiler in the laboratory employed AVT (high N 2 H 4 ) without boric acid. The results of IGA/SCC crack propagation rate measurements were compared with each other, and the three methods employed showed a good coincidence with the rate of ca. 1 x 10 -5 mm/Hr for AVT (high N 2 H 4 ) + boric acid treatment condition, in the case that crack tip boron intensity (B/O value by IMMA analysis) of more than 1 was observed

In Vitro Pollen Germination of Eichhornia crassipes (Mart. Solms: An Insight into its Preferred Mode of Clonal Reproduction

Directory of Open Access Journals (Sweden)

Somnath BHOWMIK

2012-05-01

Full Text Available Eichhornia crassipes (Mart. Solms is an aquatic invasive weed throughout the tropical and subtropical regions of the world. The plant rarely produces any fruit under natural condition In order to understand the causes of failure of seed set in this plant various aspect of pollen biology were studied. Pollen fertility and pollen viability was assessed using Muntzing� s mixture and in acetic orcein and TTZ, while pollen germination was assessed with different concentrations of sucrose supplemented with boric acid and Ca and Mg salts. The aim of present study was to find out the cause of sexual incompatibility of Eichhornia crassipes (Mart. Solms. In spite of high pollen fertility, pollen viability and pollen germination the species show hardly any fruit set under natural condition. The abnormal pollen germination like curling of pollen tubes, shrinkage of pollen tube tips and bending of pollen tube might be reasons of sexual incompatibility of this species. It is observed that the taxa required comparatively low sucrose concentration (5% for their optimal in vitro pollen germination (54.08%. Boric acid to certain extent also influences the in vitro pollen germination (56.2%. In the present investigation the nature of substrate in association with the effect of Boric acid, CaCO3, MgSO4 on the in vitro pollen germination of Eichhornia crassipes is also worked out. However the tested salts show no significant effect on pollen germination in the present study.

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.'

An overview the boron dilution issue in PWRs

International Nuclear Information System (INIS)

Hyvaerinen, J.

1994-01-01

The presentation is an overview of boron (boric acid) dilution in pressurized water reactors (PWRs). Boric acid has been widely used in PWRs as a dissolved poison, as one of the main reactivity controlling means, for a long time, from nearly but not quite from the beginning of the design, construction and operation of PWRs in the present-day sense. The specific safety issue, namely the risk of uncontrolled reactivity insertion due to inadvertent boron dilution, is discussed first, followed by a brief look on the history of boron usage in PWRs. A discussion of boron dilution phenomenology is presented next in general terms. Some particular concerns that boron dilution phenomena arouse in the minds of a regulator will also be presented before concluding with a brief look on the future of dissolved poisons. (11 refs.)

Solubilities of iron and nickel oxides under high temperature and high pressure conditions

International Nuclear Information System (INIS)

Choi, Ke-Chon; Jung, Yong-Ju; Yeon, Jei-Won; Jee, Kwang-Yong

2007-01-01

The purposes of primary coolant chemistry are to assure fuel and material integrity and to minimize out of core radiation fields. During the PWR operation, crud deposits are expected on the cladding, leading to cladding failure and raising the radioactivity. Such deposits come from the corrosion products of system surface. To achieve optimal conditions for primary coolant, basic researches on mass transfer, deposition and solubility of corrosion products are needed. The initial stage of crud formation could be the studies on the solubility of a structural material. It has been known that the solubility of metal oxides in boric acid under high temperature and high pressure condition depends on the pH and dissolved hydrogen. Thus, the effect of various pH on the solubility of metal oxide in boric acid solution was investigated in this work

Study of colloidal particles behaviour in the PWR primary circuit conditions; Etude du comportement des particules colloidales dans les conditions physicochimiques du circuit primaire des reacteurs a eau sous pression

Energy Technology Data Exchange (ETDEWEB)

Barale, M

2006-12-15

EDF wants to understand, model and limit primary circuit contamination of Pressurized Water Reactors by colloidal particles resulting from corrosion. The electrostatic behaviour of representative oxide particles (cobalt ferrite, nickel ferrite and magnetite) has been studied in primary circuit conditions with the influence of boric acid and lithium hydroxide. The isoelectric point (IEP) and the point of zero charge (PZC) of particles, measured between 5 C and 320 C, exhibit a minimum towards 200 C. The thermodynamic constants of the protonation equilibrium of surface sites were calculated. When boric acid is added, zeta potential and IEP decrease because of borate ions sorption. On the contrary, there is not effect of lithium ions. The modelling of these results under conditions representative of primary circuit shows that these oxides exhibit a negative surface charge, explaining their sorption and adhesion behaviour. (author)

X-ray fluorescence analysis of ytterbium oxide/oxalate for rare earth impurities

International Nuclear Information System (INIS)

Chandola, L.C.; Khanna, P.P.; Thomas, A.

1982-01-01

An XRF method for the determination of Ho, Er, Tm, Lu and Y oxides in Yb 2 O 3 is described. 450 mg sample in the oxalate form is mixed with 150 mg boric acid binding material and pressed into 1.25 inch diameter pellet over a supporting pellet of boric acid. The sample is irradiated by X-rays from a tungsten tube and the fluorescent X-rays are dispersed by a LiF(200) crystal in a Philips PW 1220 semiautomatic X-ray fluorescence spectrometer. The intensities of characteristic X-rays of the impurity elements are measured by a flow proportional counter or a scintillation counter. The lowest determination limit is 0.005% for Ho, Er, Tm and Y and 0.01% for Lu. Calculations for theoretical detection limit, standard deviation and uncertainty are done and presented. (author)

Study of colloidal particles behaviour in the PWR primary circuit conditions

International Nuclear Information System (INIS)

Barale, M.

2006-12-01

EDF wants to understand, model and limit primary circuit contamination of Pressurized Water Reactors by colloidal particles resulting from corrosion. The electrostatic behaviour of representative oxide particles (cobalt ferrite, nickel ferrite and magnetite) has been studied in primary circuit conditions with the influence of boric acid and lithium hydroxide. The isoelectric point (IEP) and the point of zero charge (PZC) of particles, measured between 5 C and 320 C, exhibit a minimum towards 200 C. The thermodynamic constants of the protonation equilibrium of surface sites were calculated. When boric acid is added, zeta potential and IEP decrease because of borate ions sorption. On the contrary, there is not effect of lithium ions. The modelling of these results under conditions representative of primary circuit shows that these oxides exhibit a negative surface charge, explaining their sorption and adhesion behaviour. (author)

Results Of Analytical Sample Crosschecks For Next Generation Solvent Extraction Samples Isopar L Concentration And pH

International Nuclear Information System (INIS)

Peters, T.; Fink, S.

2011-01-01

As part of the implementation process for the Next Generation Cesium Extraction Solvent (NGCS), SRNL and F/H Lab performed a series of analytical cross-checks to ensure that the components in the NGCS solvent system do not constitute an undue analytical challenge. For measurement of entrained Isopar(reg s ign) L in aqueous solutions, both labs performed similarly with results more reliable at higher concentrations (near 50 mg/L). Low bias occurred in both labs, as seen previously for comparable blind studies for the baseline solvent system. SRNL recommends consideration to use of Teflon(trademark) caps on all sample containers used for this purpose. For pH measurements, the labs showed reasonable agreement but considerable positive bias for dilute boric acid solutions. SRNL recommends consideration of using an alternate analytical method for qualification of boric acid concentrations.

Neutron shielding material and a process for producing the same

International Nuclear Information System (INIS)

Tadokoro, S.; Segawa, H.

1982-01-01

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

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

African Journals Online (AJOL)

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

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

Science.gov (United States)

2010-07-01

... than 0.2 pt of pesticide formulation Light stabilizer Hydroxypropyl guar gum Thickener Isobornyl... 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...

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.

Tanzania Journal of Science - Vol 38, No 2 (2012)

African Journals Online (AJOL)

Electrical Properties of DC Reactive Magnetron Sputtered ZnO:Al Films from Optical ... of ZnO:Al/ZnO Double Layers and the Cu(In,Ga)Se2 Solar Cell Efficiencies · EMAIL ... Management of Azole-Refractory Candida Species Using Boric Acid ...

Neutron shielding material and process for its manufacture

International Nuclear Information System (INIS)

Tadokoro, S.I; Segawa, H.

1980-01-01

The artificial resin sheets are optically transparent and mechanically strong. They are the polymerisation product of methyl methacrylate and a boric acid ester, for example. The boron content of the material is between 1% and 6% by weight (many examples). (RW) [de

Utilization of borosilicate glass for transuranic waste immobilization

International Nuclear Information System (INIS)

Ledford, J.A.; Williams, P.M.

1979-01-01

Incinerated transuranic waste and other low-level residues have been successfully vitrified by mixing with boric acid and sodium carbonate and heating to 1050 0 C in a bench-scale continuous melter. The resulting borosilicate glass demonstrates excellent mechanical durability and chemical stability

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

International Nuclear Information System (INIS)

Sakuma, Yoichi; Aida, Masao; Okamoto, Makoto; Kakihana, Hidetake

1980-01-01

Isotopic plateau displacement chromatography, a useful method for isotope separation is presented. The boric acid band formed in a column of weakly basic anion exchange resin Diaion WA21 can be eluted with pure water. In order to obtain good accumulation of the isotope effect, a series of experiments with different migration length were carried out. The boron-10 enriched part of the boric acid absorbed band was always preceded by the isotopic plateau part, in which the atomic fraction of boron-10 was maintained at its original value. The atomic fraction of boron-10 at the end of the chromatogram increased with migration length, and in the case of 256-m migration, boron-10 was enriched from its original atomic fraction of 19.84 to 91.00%, the separation factor S being constant irrespective of migration length: S = 1.0100 +- 0.0005. (author)

Post-LOCA core flushing system

International Nuclear Information System (INIS)

Boyajian, J.D.; Weinberger, P.A.

1980-01-01

A system is disclosed for flushing the core of a nuclear reactor after a loss-of-coolant accident. A pump causes flow of liquid-phase fluid from the containment-vessel sump. This flow is used to provide the motivating force for an eductor that causes suction at the hot log of the reactor. The eductor suction can draw gas-phase coolant out of the hot leg. As a result, it can reduce pressure which may be preventing the flow of liquid-phase coolant out of the hot leg. By causing liquid-phase flow through the reactor, the system ensures that particles and boric acid are flushed out of the core. The system thereby eliminates the build-up of particles and the concentrations of boric acid in the core that could result if the coolant were to leave the pressure vessel exclusively in the gas phase. 9 claims

Crack propagation rate modelling for 316SS exposed to PWR-relevant conditions

International Nuclear Information System (INIS)

Vankeerberghen, M.; Weyns, G.; Gavrilov, S.; Martens, B.; Deconinck, J.

2009-01-01

The crack propagation rate of Type 316 stainless steel in boric acid-lithium hydroxide solutions under PWR-relevant conditions was modelled. A film rupture/dissolution/repassivation mechanism is assumed and extended to cold worked materials by including a stress-dependent bare metal dissolution current density. The chemical and electrochemical conditions within the crack are calculated by finite element calculations, an analytical expression is used for the crack-tip strain rate and the crack-tip stress is assumed equal to 2.5 times the yield stress (plane-strain). First the model was calibrated against a literature published data set. Afterwards, the influence of various variables - dissolved hydrogen, boric acid and lithium hydroxide content, stress intensity, crack length, temperature, flow rate - was studied. Finally, other published crack growth rate tests were modelled and the calculated crack growth rates were found to be in reasonable agreement with the reported ones

X-ray fluorescence analysis of erbium oxide/oxalate for rare earth impurities

International Nuclear Information System (INIS)

Chandola, L.C.; Khanna, P.P.; Thomas, A.

1981-01-01

A method for the determination of Tb, Dy, Ho, Tm, Yb, Lu and Y oxides in Er 2 O 3 is described. 450 mg sample in the oxalate form is mixed with 150 mg boric acid binding material and pressed into a 1.25 inch diameter pellet over a supporting pellet of boric acid. The sample is then irradiated by X-rays from a tungsten tube and the fluorescent X-rays are dispersed by a LiF (200) crystal in a Philips PW 1220 semiautomatic X-ray fluorescence spectrometer. The intensities of characteristic X-rays of the impurity elements are measured by a flow proportional counter for all elements except yttrium for which the intensities are measured by a scintillation counter. The lowest determination limit is 0.005% for all impurities except for Yb for which it is 0.01%. Calculations for theoretical detection limit are given. (author)

Reproductive toxicity parameters and biological monitoring in occupationally and environmentally boron-exposed persons in Bandirma, Turkey.

Science.gov (United States)

Duydu, Yalçın; Başaran, Nurşen; Üstündağ, Aylin; Aydin, Sevtap; Ündeğer, Ülkü; Ataman, Osman Yavuz; Aydos, Kaan; Düker, Yalçın; Ickstadt, Katja; Waltrup, Britta Schulze; Golka, Klaus; Bolt, Hermann M

2011-06-01

Boric acid and sodium borates have been considered as being "toxic to reproduction and development", following results of animal studies with high doses. Experimentally, a NOAEL (no observed adverse effect level) of 17.5 mg B/kg-bw/day has been identified for the (male) reproductive effects of boron in a multigeneration study of rats, and a NOAEL for the developmental effects in rats was identified at 9.6 mg B/kg-bw/day. These values are being taken as the basis of current EU safety assessments. The present study was conducted to investigate the reproductive effects of boron exposure in workers employed in boric acid production plant in Bandirma, Turkey. In order to characterize the external and internal boron exposures, boron was determined in biological samples (blood, urine, semen), in workplace air, in food, and in water sources. Unfavorable effects of boron exposure on the reproductive toxicity indicators (concentration, motility, morphology of the sperm cells and blood levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and total testosterone) were not observed. The mean calculated daily boron exposure (DBE) of the highly exposed group was 14.45 ± 6.57 (3.32-35.62) mg/day. These human exposures represent worst-case exposure conditions to boric acid/borates in Turkey. These exposure levels are considerably lower than exposures, which have previously led to reproductive effects in experimental animals. In conclusion, this means that dose levels of boron associated with developmental and reproductive toxic effects in animals are by far not reachable for humans under conditions of normal handling and use.

Long-Endurance Maritime Surveillance with Ocean Glider Networks

Science.gov (United States)

2015-09-01

response to fluid viscosity , as well as magnesium sulfate and boric acid molecules found in seawater (Francois and Garrison 1982). As a result, its...Hemipelagic Terrigenous Clay ) is derived from the Bottom Sediment Type (BST) database maintained by the U.S. Naval Oceanographic Office Acoustics

Proceedings: 1991 EPRI workshop on secondary-side intergranular corrosion mechanisms

International Nuclear Information System (INIS)

Partridge, M.J.; Zemitis, W.S.

1992-08-01

A workshop on ''Secondary-Side Intergranular Corrosion Mechanisms'' was organized by EPRI as an effort to give those working in this area an opportunity to share their results, ideas, and plans. Topics covered included: (1) caustic induced intergranular attack/stress corrosion cracking (IGA/IGSCC), (2) plant experience, (3) boric acid as an IGA/IGSCC remedial measure, (4) lead induced IGA/IGSCC, and (5) acid induced IGA/IGSCC

A p An atte proces empt t ss of da oward awada s stan awan b ...

African Journals Online (AJOL)

SAM

2014-08-07

Aug 7, 2014 ... used as “sorrel meat” or Iyu (Schippers, 2000) and Borno where the .... copper sulphate (CuSO4) and selenium oxide (SeO2) in the ratio. 10:5:1 was ... boric acid containing four drops of bromocresol green/methyl red indicator ...

Analyses of CsI aerosol deposition in aerosol behavior tests in WIND project

International Nuclear Information System (INIS)

Kudo, Tamotsu; Shibazaki, Hiroaki; Hidaka, Akihide

1999-01-01

The aerosol deposition tests have been performed in WIND project at JAERI to characterize the aerosol behavior. The aerosol deposition tests named WAV1-D and WAV2-D were analyzed by aerosol behavior analysis codes, JAERI's ART and SNL's VICTORIA. The comparison calculation was performed for the confirmation of the analytical capabilities of the both codes and improvement of the models in ART. The deposition mass calculated by ART was larger than that by VICTORIA. This discrepancy is caused by differences in model for FP vapor condensation onto the wall surface. In the WAV2-D test, in which boric acid was placed on the floor area of the test section prior to the deposition phase to simulate the PWR primary coolant, there was a discrepancy in deposition mass between analytical results in both codes and experimental results. The discrepancy may be caused by existence of boric acid which is not considered in the codes. (author)

In vitro evaluation of boron tolerance in wheat (Triticum aestivum L. genotypes

Directory of Open Access Journals (Sweden)

Kondić-Špika Ankica

2010-01-01

Full Text Available Wheat tolerance to high boron concentrations was determined using mature embryo culture. The testing was performed on a modified MS nutrient medium to which boric acid was added in two concentrations: 15 mM and 30 mM. The control medium contained no excess boric acid. The experiment involved 14 Serbian varieties. After one month of cultivation callus fresh weight (CFW was measured and reductions of fresh callus weight (RFCW at boron (B concentration of 15 mM in relation to the control were calculated. The genotypes differed significantly according to their reaction to different B concentrations. Six genotypes had RFCWs below 50.0 %, while eight genotypes had RFCWs above 50.1 %. Cultivars Nevesinjka and Pesma were considered the most tolerant genotypes, while cultivars Balada and Vila were the most sensitive. The results confirmed that differences in genotype reactions to excess B are visible at the cellular level and that they may serve as a selection criterion. .

Calculation of spatial weighting functions for ex-core detectors of VVER-440 reactors by Monte Carlo method

International Nuclear Information System (INIS)

Berki, T.

2003-01-01

The signal of ex-core detectors depends not only on the total power of a reactor but also on the power distribution. The spatial weighting function establishes correspondence between the power distribution and the detector signal. The weighting function is independent of the power distribution. The weighting function is used for detector-response analyses, for example in the case of rod-drop experiments. (1) The paper describes the calculation and analysis of the weighting function of a VVER-440. The three-dimensional Monte Carlo code MCNP is used for the evaluation. Results from forward and adjoint calculations are compared. The effect of the change in the concentration of boric acid is also investigated. The evaluation of the spatial weighting function is a fixed-source neutron transport problem, which can be solved much faster by adjoint calculation, however forward calculations provide more detailed results. It is showed that the effect of boric acid upon the weighting function is negligible. (author)

GDP-D-mannose epimerase regulates male gametophyte development, plant growth and leaf senescence in Arabidopsis.

Science.gov (United States)

Qi, Tiancong; Liu, Zhipeng; Fan, Meng; Chen, Yan; Tian, Haixia; Wu, Dewei; Gao, Hua; Ren, Chunmei; Song, Susheng; Xie, Daoxin

2017-09-04

Plant GDP-D-mannose epimerase (GME) converts GDP-D-mannose to GDP-L-galactose, a precursor of both L-ascorbate (vitamin C) and cell wall polysaccharides. However, the genetic functions of GME in Arabidopsis are unclear. In this study, we found that mutations in Arabidopsis GME affect pollen germination, pollen tube elongation, and transmission and development of the male gametophyte through analysis of the heterozygous GME/gme plants and the homozygous gme plants. Arabidopsis gme mutants also exhibit severe growth defects and early leaf senescence. Surprisingly, the defects in male gametophyte in the gme plants are not restored by L-ascorbate, boric acid or GDP-L-galactose, though boric acid rescues the growth defects of the mutants, indicating that GME may regulate male gametophyte development independent of L-ascorbate and GDP-L-galactose. These results reveal key roles for Arabidopsis GME in reproductive development, vegetative growth and leaf senescence, and suggest that GME regulates plant growth and controls male gametophyte development in different manners.

Natural convection type reactor

International Nuclear Information System (INIS)

Nakayama, Takafumi; Horiuchi, Tetsuo; Moriya, Kimiaki; Matsumoto, Masayoshi; Akita, Minoru.

1988-01-01

Purpose: To improve the reliability by decreasing the number of dynamic equipments and safely shutdown the reactor core upon occurrence of accidents. Constitution: A pressure relief valve and a pressurizing tank or gravitational water falling tank disposed to the main steam pipe of a reactor are installed in combination. Upon loss-of-coolant accident, the pressure relief valve is opened to reduce the pressure in the reactor pressure vessel to the operation pressure for each of the tanks, thereby enabling to inject water in the pressurizing tank at first and, thereafter, water in the gravitational water falling tank successively to the inside of the pressure vessel. By utilizing the natural force in this way, the reliability can be improved as compared with the case of pumped water injection. Further, by injecting an aqueous boric acid to a portion of a plurality of tanks, if the control rod insertion becomes impossible, aqueous boric acid can be injected. (Takahashi, M.)

Corrosion resistance testing of high-boron-content stainless steels

International Nuclear Information System (INIS)

Petrman, I.; Safek, V.

1994-01-01

Boron steels, i.e. stainless steels with boron contents of 0.2 to 2.25 wt.%, are employed in nuclear engineering for the manufacture of baskets or wells in which radioactive fissile materials are stored, mostly spent nuclear fuel elements. The resistance of such steels to intergranular corrosion and uniform corrosion was examined in the Strauss solution and in boric acid; the dependence of the corrosion rate of the steels on their chemical composition was investigated, and their resistance was compared with that of AISI 304 type steel. Corrosion resistance tests in actual conditions of ''wet'' compact storage (demineralized water or a weak boric acid solution) gave evidence that boron steels undergo nearly no uniform corrosion and, as electrochemical measurements indicated, match standard corrosion-resistant steels. Corrosion resistance was confirmed to decrease slightly with increasing boron content and to increase somewhat with increasing molybdenum content. (Z.S.). 3 tabs., 4 figs., 7 refs

Method of manufacturing neutron protecting materials

Energy Technology Data Exchange (ETDEWEB)

Kakibana, Hidetake; Okamoto, Masazane; Fujii, Yasuhiko; Koguchi, Noboru; Takesute, Morihito; Miyamatsu, Tokuhisa

1985-06-03

Purpose: To manufacture neutron protecting materials which are highly flexible and can be shaped with ease at a good workability. Method: In this invention, natural lithium, natural boron such as Li-6 or B-10 or enriched isotope thereof with a great neutron absorption cross section is fixed to fibers. As a specific example, lumps of copolymer fibers are fabricated into weave sheets in a carding machine and applied with needle punching to prepare felt-like products. They are conditioned to OH or H type, which are respectively immersed in saturated aqueous boric acid or 1M-aqueous solution of lithium hydroxide and then dewatered and dried. As a result, boric acid type anion exchange fibers and lithium type cation exchange fibers can be obtained from the former and the latter respectively. In this way, blankets or cloths which are light in weight, flexible and have high neutron absorbing performance can be shaped. They are also in good fitting contact to a human body. (Kamimura, M.).

Italian steam power plants

Energy Technology Data Exchange (ETDEWEB)

von Rautenkranz, J

1939-01-01

A brief history of geothermal power production in Italy is presented. Boric acid has been produced on an industrial scale since 1818. The first electrical power was generated in 1904, and by 1939 the output of geothermal power plants had reached 500 GWh, with major expansion of facilities planned.

Germination and storage of pollen

NARCIS (Netherlands)

Visser, T.

1955-01-01

Germination of pear pollen markedly improved when boric acid was added to the medium. The pollen was more sensitive to boron in water than in 10 % sugar solution. Supplying weak solutions of boron to pear branches before flowering resulted in a good germination of the pollen in sugar solution

Zinc corrosion after loss-of-coolant accidents in pressurized water reactors – Physicochemical effects

Energy Technology Data Exchange (ETDEWEB)

Kryk, Holger, E-mail: h.kryk@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics, P.O. Box 510119, D-01314 Dresden (Germany); Hoffmann, Wolfgang [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics, P.O. Box 510119, D-01314 Dresden (Germany); Kästner, Wolfgang; Alt, Sören; Seeliger, André; Renger, Stefan [Hochschule Zittau/Görlitz, Institute of Process Technology, Process Automation and Measuring Technology, Theodor-Körner-Allee 16, D-02763 Zittau (Germany)

2014-12-15

Highlights: • Physicochemical effects due to post-LOCA zinc corrosion in PWR were elucidated. • Decreasing solubility of corrosion products with increasing temperature was found. • Solid corrosion products may be deposited on hot surfaces and/or within hot-spots. • Corrosion products precipitating from coolant were identified as zinc borates. • Depending on coolant temperature, different types of zinc borate are formed. - Abstract: Within the framework of the reactor safety research, generic experimental investigations were carried out aiming at the physicochemical background of possible zinc corrosion product formation, which may occur inside the reactor pressure vessel during the sump circulation operation after loss-of-coolant accidents in pressurized water reactors. The contact of the boric acid containing coolant with hot-dip galvanized steel containment internals causes corrosion of the corresponding materials resulting in dissolution of the zinc coat. A retrograde solubility of zinc corrosion products with increasing temperature was observed during batch experiments of zinc corrosion in boric acid containing coolants. Thus, the formation and deposition of solid corrosion products cannot be ruled out if the coolant containing dissolved zinc is heated up during its recirculation into hot regions within the emergency cooling circuit (e.g. hot-spots in the core). Corrosion experiments at a lab-scale test facility, which included formation of corrosion products at a single heated cladding tube, proved that dissolved zinc, formed at low temperatures in boric acid solution by zinc corrosion, turns into solid deposits of zinc borates when contacting heated zircaloy surfaces during the heating of the coolant. Moreover, the temperature of formation influences the chemical composition of the zinc borates and thus the deposition and mobilization behavior of the products.

Zinc corrosion after loss-of-coolant accidents in pressurized water reactors – Physicochemical effects

International Nuclear Information System (INIS)

Kryk, Holger; Hoffmann, Wolfgang; Kästner, Wolfgang; Alt, Sören; Seeliger, André; Renger, Stefan

2014-01-01

Highlights: • Physicochemical effects due to post-LOCA zinc corrosion in PWR were elucidated. • Decreasing solubility of corrosion products with increasing temperature was found. • Solid corrosion products may be deposited on hot surfaces and/or within hot-spots. • Corrosion products precipitating from coolant were identified as zinc borates. • Depending on coolant temperature, different types of zinc borate are formed. - Abstract: Within the framework of the reactor safety research, generic experimental investigations were carried out aiming at the physicochemical background of possible zinc corrosion product formation, which may occur inside the reactor pressure vessel during the sump circulation operation after loss-of-coolant accidents in pressurized water reactors. The contact of the boric acid containing coolant with hot-dip galvanized steel containment internals causes corrosion of the corresponding materials resulting in dissolution of the zinc coat. A retrograde solubility of zinc corrosion products with increasing temperature was observed during batch experiments of zinc corrosion in boric acid containing coolants. Thus, the formation and deposition of solid corrosion products cannot be ruled out if the coolant containing dissolved zinc is heated up during its recirculation into hot regions within the emergency cooling circuit (e.g. hot-spots in the core). Corrosion experiments at a lab-scale test facility, which included formation of corrosion products at a single heated cladding tube, proved that dissolved zinc, formed at low temperatures in boric acid solution by zinc corrosion, turns into solid deposits of zinc borates when contacting heated zircaloy surfaces during the heating of the coolant. Moreover, the temperature of formation influences the chemical composition of the zinc borates and thus the deposition and mobilization behavior of the products

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

International Nuclear Information System (INIS)

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

1986-01-01

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

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.

Experimental Investigation on the Effects of Coolant Concentration on Sub-Cooled Boiling and Crud Deposition on Reactor Cladding at Prototypical PWR Operating Conditions

Energy Technology Data Exchange (ETDEWEB)

Schultis, J., Kenneth; Fenton, Donald, L.

2006-10-20

Increasing demand for energy necessitates nuclear power units to increase power limits. This implies significant changes in the design of the core of the nuclear power units, therefore providing better performance and safety in operations. A major hindrance to the increase of nuclear reactor performance especially in Pressurized Deionized water Reactors (PWR) is Axial Offset Anomaly (AOA)--the unexpected change in the core axial power distribution during operation from the predicted distribution. This problem is thought to be occur because of precipitation and deposition of lithiated compounds like boric acid (H{sub 2}BO{sub 3}) and lithium metaborate (LiBO{sub 2}) on the fuel rod cladding. Deposited boron absorbs neutrons thereby affecting the total power distribution inside the reactor. AOA is thought to occur when there is sufficient build-up of crud deposits on the cladding during subcooled nucleate boiling. Predicting AOA is difficult as there is very little information regarding the heat and mass transfer during subcooled nucleate boiling. An experimental investigation was conducted to study the heat transfer characteristics during subcooled nucleate boiling at prototypical PWR conditions. Pool boiling tests were conducted with varying concentrations of lithium metaborate (LiBO{sub 2}) and boric acid (H{sub 2}BO{sub 3}) solutions in deionized water. The experimental data collected includes the effect of coolant concentration, subcooling, system pressure and heat flux on pool the boiling heat transfer coefficient. The analysis of particulate deposits formed on the fuel cladding surface during subcooled nucleate boiling was also performed. The results indicate that the pool boiling heat transfer coefficient degrades in the presence of boric acid and lithium metaborate compared to pure deionized water due to lesser nucleation. The pool boiling heat transfer coefficients decreased by about 24% for 5000 ppm concentrated boric acid solution and by 27% for 5000 ppm

Comparative antibacterial activity of topical antiseptic eardrops against methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa.

Science.gov (United States)

Youn, Cha Kyung; Jang, Sook-Jin; Jo, Eu-Ri; Choi, Ji Ae; Sim, Ju-Hwan; Cho, Sung Il

2016-06-01

Aural irrigation using antiseptic solutions can be an effective medical treatment of chronic suppurative otitis media (CSOM) owing to the increasing prevalence of antibiotic-resistant CSOM infections. In the present study, we compared the antimicrobial activities of 100% Burow's solution, 50% Burow's solution, 2% acetic acid, vinegar with water (1:1), and 4% boric acid solution against methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus (MSSA), quinolone-resistant Pseudomonas aeruginosa (QRPA), and quinolone-susceptible P. aeruginosa (QSPA) in vitro. We examined the antimicrobial activities of five antiseptic solutions against MRSA, MSSA, QRPA, and QSPA. The antimicrobial activities of the solutions were calculated as a percentage of the surviving microorganisms by dividing the viable count in each antiseptic solution with that in control. The time (D10 value) required for each of the five solutions to inactivate 90% of the microorganism population was also investigated. Burow's solution exhibited the highest antimicrobial activity and the lowest D10 value against MRSA, MSSA, QRPA, and QSPA, followed by 2% acetic acid, vinegar with water (1:1), and 4% boric acid solution. Our results indicate that Burow's solution has the most potent activity against bacteria including antibiotic-resistant strains. Twofold dilution of the solution is recommended to avoid ototoxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Microwave synthesis of homogeneous and highly luminescent BCNO nanoparticles for the light emitting polymer materials

Energy Technology Data Exchange (ETDEWEB)

Iwasaki, Hideharu [Battery Materials Laboratory, Kurashiki Research Center, Kuraray Co., Ltd., 2045-1, Sakazu, Kurashiki, Okayama 710-0801 (Japan); Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739 8527 (Japan); Ogi, Takashi, E-mail: ogit@hiroshima-u.ac.jp [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739 8527 (Japan); Iskandar, Ferry [Department of Physics, Institute of Technology Bandung, Ganesha 10, Bandung 40132, West Java (Indonesia); Aishima, Kana; Okuyama, Kikuo [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739 8527 (Japan)

2015-10-15

Nano-sized boron carbon oxynitride (BCNO) phosphors around 50 nm containing no rare earth metal and free from color heterogeneity were synthesized from mixtures of boric acid, urea, and citric acid by microwave heating with substantially shorter reaction times and lower temperatures than in the conventional BCNO preparation method such as electric-furnace heating. The emission wavelength of the phosphors varied with the mixing ratio of raw materials and it was found that lowering the proportion of urea to boric acid or citric acid tended to increase the internal quantum yield and shorten the emission wavelength under excitation at 365 nm. It was also found for the first time that a light-emitting polymer could be synthesized from a mixture of the prepared BCNO nanoparticles and a polyvinyl alcohol. This polymer composite exhibited uniform dispersion and stabilization of the luminescence and had a high internal quantum yield of 54%, which was higher than that of the phosphor alone. - Highlights: • Nano-sized BCNO phosphor was synthesized via microwave heating. • BCNO nanophosphor has homogeneous and high luminescence. • Emission wavelength was tunable by changing the ratio of precursor components. • BCNO nanophosphor can be easily dispersed in a polyvinyl alcohol. • BCNO–polymer composite exhibited uniform high internal quantum yield.

Effect of boron and phosphate compounds on physical, mechanical, and fire properties of wood-polypropylene composites

Science.gov (United States)

Nadir Ayrilmis; Turgay Akbulut; Turker Dundar; Robert H. White; Fatih Mengeloglu; Umit Buyuksari; Zeki Candan; Erkan Avci

2012-01-01

Physical, mechanical, and fire properties of the injection-molded wood flour/polypropylene composites incorporated with different contents of boron compounds; borax/boric acid and zinc borate, and phosphate compounds; mono and diammonium phosphates were investigated. The effect of the coupling agent content, maleic anhydride-grafted polypropylene, on the properties of...

Impact of impregnation with boron compounds on combustion ...

African Journals Online (AJOL)

This study examined the impacts of varnishing after impregnation with boron compounds on combustion properties of oriental beech. The test samples prepared from oriental beech (Fagus orientalis Lipsky) wood were impregnated according to ASTM D 1413–76–99 with boric acid (Ba) or borax (Bx) using a vacuum ...

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

Direct monitoring by carbon-13 nuclear magnetic resonance spectroscopy of the metabolism and metabolic rate of 13C-labeled compounds in vivo.

Science.gov (United States)

Iida, K; Hidoh, O; Fukami, J; Kajiwara, M

1991-01-01

Carbon-13 nuclear magnetic resonance spectroscopy has been used to observe the transformations of [1-13C]-D-glucose to [1,1'-13C2]-D-trehalose, and [3-13C]-L-alanine to [2-13C]-L-glutamic acid in the living body of Gryllodes sigillatus. [3-13C]-D-Alanine was not metabolized. The metabolic rate of [1-13C]-D-glucose was found to be altered by prior injection of boric acid.

Acquisition of Heat Stable Enzymes from Thermophilic Microorganisms: Peroxidases, Ureases, and Glucose Oxidases.

Science.gov (United States)

1992-04-01

heptahydrate, 1.50 g/L boric acid, 0.05 g/L copper sulfate pentahydrate . 0.20 g/L molybdic acid dihydrate sodium salt and 0.05 g/L cobalt chloride...vanadium, cobalt, magnesium, potassium, zinc, copper , manganese, sodium, chloride and various forms of nitrogen. In addition to pH and temperature...growth may not coincide with the optimal conditions for production of the desired enzyme. For isolate #135, the sulfate , magnesium, potassium and

Physical, mechanical, and fire properties of oriented strandboard with fire retardant treated veneers

Science.gov (United States)

Nadir Ayrilmis; Zeki Candan; Robert White

2007-01-01

This study evaluated physical, mechanical and fire properties of oriented strand boards (OSB) covered with fire retardant treated veneers. The beech (Fagus orientalis Lipsky) veneers were treated with either monoammonium phosphate, diammonium phosphate, lime water or a borax/boric acid (1 : 1 by weight) mixture. Physical and mechanical properties of the specimens were...

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences. G N Mukherjee. Articles written in Journal of Chemical Sciences. Volume 114 Issue 3 June 2002 pp 163-174 Inorganic and Analytical. Mixed ligand complex formation of Fe with boric acid and typical N-donor multidentate ligands · G N Mukherjee Ansuman Das · More Details ...

Ultra low and negative expansion glass–ceramic materials ...

Indian Academy of Sciences (India)

Ultra low and negative expansion glass–ceramic materials have been obtained from pyrophyllite and blast furnace slag. The batch composition was modified with the addition of lithium carbonate, hydrated alumina, boric acid and nucleating agent (titania). The batch was melted at 1400°C followed by casting in the form of ...

Ammonia role in WWER primary circuit water chemistry optimization

International Nuclear Information System (INIS)

Kritskij, V.G.; Stjagkin, P.S.; Chvedova, M.N.; Slobodov, A.A.

1999-01-01

Ammonia influence on iron crud's solubility at 300 deg. C and different relations of boric acid and alkaline cation sum are considered. Reduction of dose rate on WWER-440 steam generators at average ammonia concentration increasing is empirically explained. Practical recommendations on optimization of WWER primary circuit water chemistry are given. (author)

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)

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

Boron Removal in Radioactive Liquid Waste by Forward Osmosis Membrane

Energy Technology Data Exchange (ETDEWEB)

Hwang, Dooseong; Choi, Hei Min; Lee, Kune Woo; Moon Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

These wastes contain about 0.3-0.8 wt% boric acid and have been concentrated through an evaporation treatment. Boric acid tends to crystallize owing to its solubility, and to plug the evaporator. The volume reduction obtained through evaporation is limited by the amount of boric acid in the waste. As an emerging technology, forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination. FO is a membrane process in which water flows across a semi-permeable membrane from a feed solution of lower osmotic pressure to a draw solution of higher osmotic pressure. However, very few studies on the removal of boron by FO have been performed. The objective of this study is to evaluate the possibility of boron separation in radioactive liquid waste by FO. In this study, the performance of FO was investigated to separate boron in the simulated liquid waste under the factors such as pH, osmotic pressure, ionic strength of the solution, and membrane characteristic. The boron separation in radioactive borate liquid waste was investigated with an FO membrane. When the feed solution containing boron is treated by the FO membrane, the boron permeation depends on the type of membrane, membrane orientation, pH of the feed solution, salt and boron concentration in the feed solution, and osmotic pressure of the draw solution. The boron flux begins to decline from pH 7, and increases with an increase in the osmotic driving force. The boron flux of the CTA-ES and ALFD membrane orientation is higher than those of the CTA-NW and ALFF orientation, respectively. The boron permeation rate is constant regardless of the osmotic pressure and membrane orientation. The boron flux decreases slightly with the salt concentration, but it is not heavily influenced at a low salt concentration.

Boron Removal in Radioactive Liquid Waste by Forward Osmosis Membrane

International Nuclear Information System (INIS)

Hwang, Dooseong; Choi, Hei Min; Lee, Kune Woo; Moon Jeikwon

2014-01-01

These wastes contain about 0.3-0.8 wt% boric acid and have been concentrated through an evaporation treatment. Boric acid tends to crystallize owing to its solubility, and to plug the evaporator. The volume reduction obtained through evaporation is limited by the amount of boric acid in the waste. As an emerging technology, forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination. FO is a membrane process in which water flows across a semi-permeable membrane from a feed solution of lower osmotic pressure to a draw solution of higher osmotic pressure. However, very few studies on the removal of boron by FO have been performed. The objective of this study is to evaluate the possibility of boron separation in radioactive liquid waste by FO. In this study, the performance of FO was investigated to separate boron in the simulated liquid waste under the factors such as pH, osmotic pressure, ionic strength of the solution, and membrane characteristic. The boron separation in radioactive borate liquid waste was investigated with an FO membrane. When the feed solution containing boron is treated by the FO membrane, the boron permeation depends on the type of membrane, membrane orientation, pH of the feed solution, salt and boron concentration in the feed solution, and osmotic pressure of the draw solution. The boron flux begins to decline from pH 7, and increases with an increase in the osmotic driving force. The boron flux of the CTA-ES and ALFD membrane orientation is higher than those of the CTA-NW and ALFF orientation, respectively. The boron permeation rate is constant regardless of the osmotic pressure and membrane orientation. The boron flux decreases slightly with the salt concentration, but it is not heavily influenced at a low salt concentration

Alternative water chemistry for the primary loop of PWR plants

Energy Technology Data Exchange (ETDEWEB)

Henzel, N [Siemens AG Unternehmensbereich KWU, Erlangen (Germany)

1997-02-01

Advanced fuel element concepts (longer cycles, higher burnup, increased rod power) call for more reactivity binding capacity and, moreover, might produce higher void fractions, particularly in the hot channel. Thus, on the one hand, more alcalizing agent is needed to maintain a high coolant pH according to the approved ``modified boron-lithium mode of operation`` in the presence of more boric acid (chemical shim); on the other hand, increasing enrichment of coolant constituents due to local boiling (higher void fraction), which must not result in accelerated corrosion of fuel cladding and structural materials, imposes enhanced requirements on both, materials technology and water chemistry. At present, the use of boric acid enriched in B10 (the isotope effective in terms of reactivity control) appears to advantageously compromise in capturing more neutrons with less total boron while maintaining or even slightly reducing lithium concentrations at the same time. There is no feasible alternative for boric acid used as the chemical shim and for hydrogen gas as the reducing agent used to suppress oxygen formation by water radiolysis. Systematic screening as performed in phase 1 of a recent project proved potassium hydroxide to be the only potential candidate to favourably replace lithium 7 hydroxide as an alcalizing agent. Unfortunately, the results of pertinent comparative corrosion tests are not unambiguous, and available operational experience with potassium hydroxide in WWER plants is not readily applicable to western world-type PWR plants. Therefore, a switch-over from lithium to potassium can be envisaged only subsequent to a comprehensive qualification program which is planned to be the objective of phase 2 of the project. This program should also comprise zinc addition tests in order to confirm the alleged positive impact of this element on corrosion rates and activity buildup. (Abstract Truncated)

Experimental study of asymmetric boron dilution at VVER-1000 of Kudankulam NPP and its simulation

Energy Technology Data Exchange (ETDEWEB)

Tsyganov, Sergey V.; Kotsarev, Alexander V.; Baykov, Alexander V. [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

2017-09-15

The Kudankulam NPP units contain additional and unique for VVER Quick Boron Injection System (QBIS) for beyond-design-basis accident management without scram. During the physical start-up stage at hot zero power of both Kudankulam units, special tests were performed to assess the efficiency of the system. In the course of test three out of four QBIS tanks had been promptly opened and it led to the asymmetrical injection of boric acid into the core. The scenario of the tests may address to the inhomogeneous boron dilution process that is now an essential part of safety analysis of pressurised water reactors. The simulation of the process, including ex-core ion chambers readings, has been accomplished using ATHLET/BIPR-VVER code. Behaviour of some reactor parameters in the course of the test and some results of the simulation are discussing in the paper. Authors believe the process of the asymmetrical injection of boric acid may be useful for verification and validation of coupled neutronic and thermo-hydraulic codes widely used for safety analysis, including analysis of boron dilution accident.

A review of pH calculation and corrosion product solubilities under PWR primary coolant chemistry conditions

International Nuclear Information System (INIS)

Thornton, E.W.; Polley, M.V.

1986-12-01

The calculation of high temperature pH in boric acid solutions is discussed and various relationships for the ionisation constant Ksub(w) or ion product Qsub(w) for water are reviewed. It is shown that the boric acid equilibria of Mesmer, Baes and Sweeton remain virtually unaltered when Marshall and Franck's relationship for Ksub(w) is substituted in a re-analysis of Mesmer, Baes and Sweeton's original experimental data. Magnetite solubility data and Westinghouse's studies of iron, nickel and cobalt solubility from mixed ferrites are collated and consideration is given to experimental difficulties which could have contributed to the variability in the data. Thermodynamic model fits have been computerised and used to compare different studies and to determine pH values at which the temperature dependence of solubility is predicted to be zero. Consideration is given to the differing dependences of solubility on dissolved hydrogen concentration in the three model fits. Two models for predicting iron and nickel solubility with respect to non-stoichiometric nickel ferrites are briefly discussed showing that only one of these is likely to be credible. (author)

A simple and efficient method of nickel electrodeposition for the cyclotron production of 64Cu

International Nuclear Information System (INIS)

Manrique-Arias, Juan C.; Avila-Rodriguez, Miguel A.

2014-01-01

Nickel targets for the cyclotron production of 64 Cu were prepared by electrodeposition on a gold backing from nickel chloride solutions using boric acid as buffer. Parameters studied were nickel chloride and boric acid concentration, temperature and current density. All plating conditions studied were successful obtaining efficiencies of approximately 90% in 2–3 h, reaching almost quantitative plating (>97%) in 10–20 h depending on the current density. All plated targets withstood proton irradiations up to 40 µA for 2 h. Recovered nickel was successfully recycled and reused with an overall efficiency >95%. - Highlights: • Simple and efficient method of Ni electrodeposition from NiCl 2 solutions. • Represents an improvement over current methods for the preparation of Ni targets. • All plated targets underwent irradiation and withstood currents up to 40 µA for 2 h. • Nickel target material was recycled and reused with an overall efficiency >95%. • Specific activity of 64 Cu was similar than that obtained with older methods of Ni plating

Comparison of EPR response of alanine and Gd₂O₃-alanine dosimeters exposed to TRIGA Mainz reactor.

Science.gov (United States)

Marrale, M; Schmitz, T; Gallo, S; Hampel, G; Longo, A; Panzeca, S; Tranchina, L

2015-12-01

In this work we report some preliminary results regarding the analysis of electron paramagnetic resonance (EPR) response of alanine pellets and alanine pellets added with gadolinium used for dosimetry at the TRIGA research reactor in Mainz, Germany. Two set-ups were evaluated: irradiation inside PMMA phantom and irradiation inside boric acid phantom. We observed that the presence of Gd2O3 inside alanine pellets increases the EPR signal by a factor of 3.45 and 1.24 in case of PMMA and boric acid phantoms, respectively. We can conclude that in the case of neutron beam with a predominant thermal neutron component the addition of gadolinium oxide can significantly improve neutron sensitivity of alanine pellets. Monte Carlo (MC) simulations of both response of alanine and Gd-added alanine pellets with FLUKA code were performed and a good agreement was achieved for pure alanine dosimeters. For Gd2O3-alanine deviations between MC simulations and experimental data were observed and discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improvement on control of waste disposal system at Genkai Nuclear Power Station No.1 and No.2 unit

International Nuclear Information System (INIS)

Morooka, Masatoshi; Tsutsumi, Akria

1989-01-01

At Genkai Nuclear Power Station, the operational and control systems of the boric acid evaporator, waste liquid evaporator and gaseous waste disposal system were converted from general purpose analong systems to computer instrumentation and control systems in order to improve their operability and controllability. The equipments were operated by batch processing system, so plant operators were required to operate them manually. By introducing the computer instrumentation and control systems, the automatic operation of the equipments has become possible. Furthermore, it has become possible to monitor the relevant parameters intensively with a CRT in the operating room, and it contributes to the improvement of reliability and labor saving. The operation of No.1 plant was begun in October, 1975, and No.2 plant in March, 1981. Both are the PWR plants of 625 MVA capacity. The outline of the power station facilities, the background of the reconstruction, the problems and the plan of reconstruction for the boric acid recovery facility, waste liquid evaporator and gas compressor, the peculiarity of the reconstruction works, and the effect of introducing the new systems are reported. (Kako, I.)

Fire-retardant-treated strandboard : properties and fire performance

Science.gov (United States)

Jerrold Winandy; Qingwen Wang; Robert H. White

2008-01-01

This study evaluated a series of single-layer, randomly oriented strandboard panels made with one resin type, a single resin loading level, and four fire-retardant-treatment levels. The fire retardant (FR) evaluated was a pH-buffered combination of boric acid and organic phosphate. Siberian larch strands were separated into five batches. One batch of strands served as...

The determination, by x-ray-fluorescence spectrometry, of gold, silver, and base metals on activated carbon

International Nuclear Information System (INIS)

Wall, G.; Jacobs, J.J.; Dixon, K.

1980-01-01

The method proposed involves ashing of the sample at a low temperature in a muffle furnace, mixing of the ash with alumina and boric acid in a Siebtechnik mill, and briquetting of the mixture. The elements are measured in the briquette by the use of x-ray fluorescence spectrometry. The detailed laboratory method is given in an appendix [af

PWR auxiliary systems, safety and emergency systems, accident analysis, operation

International Nuclear Information System (INIS)

Meyer, P.J.

1976-01-01

The author presents a description of PWR auxiliary systems like volume control, boric acid control, coolant purification, -degassing, -storage and -treatment system and waste processing systems. Residual heat removal systems, emergency systems and containment designs are discussed. As an accident analysis the author gives a survey over malfunctions and disturbances in the field of reactor operations. (TK) [de

Effect of Boron and Phosphate compounds on Thermal and Fire Properties of wood/HDPE composites

Science.gov (United States)

Turgay Akbulut; Nadir Ayrilmis; Turker Dundar; Ali Durmus; Robert H. White; Murat Teker

2011-01-01

Melting and non-isothermal crystallization behaviors, oxidative induction time, and fire performance of the injection-molded wood flour-high density polyethylene (HDPE) composites (WPCs) incorporated with different levels (4, 8, or 12 wt %) of boron compounds [borax/boric acid (BX/BA) (0.5:0.5 wt %), zinc borate (ZB)] and phosphorus compounds [mono- and di-ammonium...

Dismountable wall for radiation shielding and screen realized from this wall

International Nuclear Information System (INIS)

Blomart, P.

1988-01-01

The wall for protection against neutrons and gamma radiations is made of bricks with a shoulder on the upper and side faces and the complementary shape on the lower face to provide a barrier to radiations. Bricks are made of a heavy material for gamma absorption and of epoxy resin, boric acid and hydrated alumina [fr

77 FR 43382 - Millstone Power Station, Unit 2; Exemption

Science.gov (United States)

2012-07-24

... Transition from Main Steam Safety Valves. Check Local Condensate Storage OMA 20 Tank Level Indication at LIS-5489. Open Breaker to Fail Valve 2-CH- OMA 6 517 Closed. Check Local Level Indication at LI- OMA 18 206A. Check Local Boric Acid Storage OMA 19 Tank Level Indication at LI-208A. Open Valve 2-CH-429 to...

Synthesis of nanocrystalline TiO 2 thin films by liquid phase ...

Indian Academy of Sciences (India)

A transparent, high purity titanium dioxide thin film composed of densely packed nanometer sized grains has been successfully deposited on a glass substrate at 30°C from an aqueous solution of TiO2–HF with the addition of boric acid as a scavenger by liquid phase deposition technique. From X-ray diffraction ...

ELECTROCHEMICAL DETERMINATION OF ETHANOL, 2 ...

African Journals Online (AJOL)

2014-12-31

Dec 31, 2014 ... ABSTRACT. In this work, we present the modification of a glassy carbon electrode with nickel oxide film which is performed in two successive steps. In the first one, the electrochemical deposition of metallic nickel on the glassy carbon electrode (GCE) is achieved in 0.1M boric acid; in the second step, the ...

Safety aspects in a chemical exchange process plant

International Nuclear Information System (INIS)

Sharma, B.K.

2016-01-01

Based on a chemical exchange process involving solid liquid exchange, studies have been undertaken to enrich 10 B isotope of boron using ion exchange chromatography in which a strong base anion exchange resin in hydroxyl form is equilibrated with boric acid solution in presence of mannitol (a complexing reagent to boric acid) to enhance the acidity and hence the isotopic exchange separation factor for 10 B = 11 B exchange reaction. Using the electrochemical techniques such as pH-metry and conductimetry, the choice of a suitable complexing reagent was made amongst ethylene glycol, propylene glycol, dextrose and mannitol for cost-effective separation of isotopes of boron and monitoring of band movements using these electrochemical techniques. The optimum conditions for the regeneration of strong base anion exchange resins of type-I and type-II were determined for cost-effective separation of isotopes of boron by ion exchange chromatography. The possibility of using unspent alkali content of the effluent was also exploited. Removal of carbonate impurity from Rayon grade caustic lye (used as regenerant after dilution) and recycling of Ba(OH) 2 was studied to avoid waste disposal problems. This process is an industrially viable process. The various safety aspects followed during operation of this plant are described in this paper. (author)

Development of Mg B4 O7:Dy thermoluminescent solid dosemeter for using on the thermal neutron dosimetry

International Nuclear Information System (INIS)

Potiens Junior, A.J.; Campos, L.L.; Todo, A.S.

1992-01-01

The magnesium tetraborate doped with dysprosium (Mg B 4 O 7 :O y ) thermoluminescent phosphor is developed, containing boron, which boron 10 isotope has high cross section for thermal neutrons by 10 B (n,α) 7 Li reaction. The nitric acid concentration, the number of washing for removing the excess of boric acid, the powder granulation of Mg B 4 O 7 :O y , the percentage of teflon used as binder and the reproducibility of thermoluminescent answer are also presented. (C.G.C.)

Use of water as displacing agent in ion exchange chromatographic separation of isotope of boron using weak base ion exchange resin

International Nuclear Information System (INIS)

Sharma, B.K.; Mohanakrishnan, G.; Anand Babu, C.; Krishna Prabhu, R.

2008-01-01

Experiments were undertaken to study the feasibility of using weakly basic anion exchange resin for enrichment of isotopes of boron by ion exchange chromatography and water as eluent. The results of experiments carried out to determine total chloride capacity (TCC), strong base capacity (SBC) of the resin at different concentrations of boric acid and enrichment profiles are reported in this paper. (author)

An investigation into the efficiency of ion-exchange membranes in simulated PWR coolants

International Nuclear Information System (INIS)

Clune, T.

1980-11-01

This report describes an investigation of the retention efficiency of cation-exchange membranes for magnesium, calcium and nickel ions in PWR-coolant type solutions containing 2 ppm lithium (as lithium hydroxide) and 1000 ppm boron (as boric acid). By analysis of the membranes themselves or of the effluent, the retention characteristics of the membranes in various experimental conditions have been examined. (author)

Maintenance of shutdown system in the reactor core to minimize the radioactive waste generation

International Nuclear Information System (INIS)

Ponzoni Filho, P.; Fernandes, V.B.

1988-01-01

This paper recommends a modification on the actual strategy of going from Cold-Shutdown to Critical, that will save about 6000 liter of boric acid and 30,000 liters of demineralized water for each reactor criticalization. This strategy will reduce the radioactive waste disposal volume to only about 5% of what would be generated following the actual strategy. (author) [pt

Effect of boron compounds on physical, mechanical, and fire properties of injection molded wood plastic composites

Science.gov (United States)

Nadir Ayrilmis; Turgay Akbulut; Turker Dundar; Robert H. White; Fatih Mengeloglu; Zeki Candan; Umit Buyuksari; Erkan Avci

2011-01-01

Physical, mechanical, and fire properties of the injection-molded wood flour/polypropylene composites (WPCs) incorporated with different levels of boron compounds, borax/boric acid (BX/BA) (0.5:0.5 wt %) and zinc borate (ZB) (4, 8, or 12 wt %) were investigated. The effect of the coupling agent loading (2, 4, or 6 wt %), maleic anhydride-grafted PP (MAPP), on the...

Method of solidifying liquid radioactive wastes

International Nuclear Information System (INIS)

Pekar, A.; Petrovic, J.; Timulak, J.

1987-01-01

Liquid radioactive waste containing boric acid salts is mixed with zeolite tuff and neutralized by lime. Power plant fly ash containing single-component or mixed Portland cement is then added to the mixture. Prior to packaging, anion-active bitumen emulsion or an aqueous emulsion of fatty acid salts and of free fatty acids insoluble in water can be added. Examples are given listing accurate proportions of the individual components. The advantage of the said solidification method is the use of easily available raw materials and improved values of extractability of the resulting product radionuclides. (E.S.)

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

Science.gov (United States)

Volpi, Nicola

2009-04-05

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

[Progress in sample preparation and analytical methods for trace polar small molecules in complex samples].

Science.gov (United States)

Zhang, Qianchun; Luo, Xialin; Li, Gongke; Xiao, Xiaohua

2015-09-01

Small polar molecules such as nucleosides, amines, amino acids are important analytes in biological, food, environmental, and other fields. It is necessary to develop efficient sample preparation and sensitive analytical methods for rapid analysis of these polar small molecules in complex matrices. Some typical materials in sample preparation, including silica, polymer, carbon, boric acid and so on, are introduced in this paper. Meanwhile, the applications and developments of analytical methods of polar small molecules, such as reversed-phase liquid chromatography, hydrophilic interaction chromatography, etc., are also reviewed.

Mix for production of heavy concretes

International Nuclear Information System (INIS)

Skvara, F.; Halen, S.; Kolar, K.; Novotny, J.; Zadak, Z.; Zezulka, J.

1981-01-01

The mix consists of 76 to 99.79 wt.% of cement clay of a specific area of 150 to 3000 m 2 /kg, of heavy aggregate (in a ratio of 1 part of cement clay to more than 1 part of the heavy aggregate) and of 0.1 to 8 wt.% of lignosulphonic acid salt. The mix also contains 0.1 to 8 wt.% of boric acid, 0.01 to 8 wt.% of a carbonate or a hydrogen carbonate of an alkali metal. (H.S.)

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.

Simple methods for in vitro pollen germination and pollen preservation of selected species of the genus Agave

Directory of Open Access Journals (Sweden)

Sigifredo López Díaz

2008-01-01

Full Text Available Simple methods to evaluate the viability and to preserve Agave tequilana Weber var. azul and A. angustifolia Haw pollen were established. Pollen viability was assessed by improving a growing media and evaluating three common pollen germination media components: sucrose, boric acid, and calcium ion. Optimal germination of pollen was obtained at 0.300 M sucrose, 0.324 mM boric acid, and 1.219 mM calcium nitrate and incubated at a temperature of 25°C. Agave pollen was preserved in olive oil and organic solvents. Olive oil, which is immiscible with water, provides an anhydrous environment and limits available oxygen, conditions similar to those provided by some organic solvents. Fresh pollen was put into eppendorf tubes containing n-butanol, n-propanol, isopropanol, extra virgin olive oil and preserved at -20, 4, and 25°C. The germination of the preserved pollen was scored at different time periods during preservation employing the optimal germination medium. The viability of pollen grains preserved at -20°C in olive oil, proved olive oil as an efficient medium for agave pollen preservation for at least 6 months.

Depth protection system

International Nuclear Information System (INIS)

Arita, Setsuo; Izumi, Shigeru; Suzuki, Satoru; Noguchi, Atomi.

1988-01-01

Purpose: To previously set a nuclear reactor toward safety side by the reactor scram if an emergency core cooling system is failed to operate. Constitution If abnormality occurs in an emergency core cooling system or an aqueous boric acid injection system, a reactor protection system is operated and, if the reactor protection system shows an abnormal state, a control rod withdrawal inhibition system is operated as a fundamental way. For instance, when the driving power source voltage for the emergency core cooling system is detected and, if it is lower than a predetermined value, the reactor protection system is operated. Alternatively, if the voltage goes lower than the predetermined value, the control rod withdrawal is inhibited. In addition, stopping for the feedwater system is inhibited. Further, integrity of the driving means for the emergency core cooling system is positively checked and the protection function is operated depending on the result of check. Since the nuclear reactor can be set toward the safety side even if the voltage for the driving power source of the aqueous boric acid injection system is lower than a predetermined value, the reactor safety can further be improved. (Horiuchi, T.)

Study of water radiolysis in relation with the primary cooling circuit of pressurized water reactors; Etude sur la radiolyse de l`eau en relation avec le circuit primaire de refroidissement des reacteurs nucleaires a eau sous pression

Energy Technology Data Exchange (ETDEWEB)

Pastina, B

1997-07-01

This memorandum shows a fundamental study on the water radiolysis in relation with the cooling primary circuit of PWR type reactors. The water of the primary circuit contains boric acid a soluble neutronic poison and also hydrogen that has for role to inhibit the water decomposition under radiation effect. In the aim to better understand the mechanism of dissolved hydrogen action and to evaluate the impact of several parameters on this mechanism, aqueous solutions with boric acid and hydrogen have been irradiated in a experimental nuclear reactor, at 30, 100 and 200 Celsius degrees. It has been found that, with hydrogen, the water decomposition under irradiation is a threshold phenomenon in function of the ratio between the radiation flux `1` B(n, )`7 Li and the gamma flux. When this ratio become too high, the number of radicals is not sufficient to participate at the chain reaction, and then water is decomposed in O{sub 2} and H{sub 2}O{sub 2} in a irreversible way. The temperature has a beneficial part on this mechanism. The iron ion and the copper ion favour the water decomposition. (N.C.). 83 refs.

Electrochemical growth of Co nanowires in ultra-high aspect ratio InP membranes: FFT-impedance spectroscopy of the growth process and magnetic properties.

Science.gov (United States)

Gerngross, Mark-Daniel; Carstensen, Jürgen; Föll, Helmut

2014-01-01

The electrochemical growth of Co nanowires in ultra-high aspect ratio InP membranes has been investigated by fast Fourier transform-impedance spectroscopy (FFT-IS) in the frequency range from 75 Hz to 18.5 kHz. The impedance data could be fitted very well using an electric circuit equivalent model with a series resistance connected in series to a simple resistor-capacitor (RC) element and a Maxwell element. Based on the impedance data, the Co deposition in ultra-high aspect ratio InP membranes can be divided into two different Co deposition processes. The corresponding share of each process on the overall Co deposition can be determined directly from the transfer resistances of the two processes. The impedance data clearly show the beneficial impact of boric acid on the Co deposition and also indicate a diffusion limitation of boric acid in ultra-high aspect ratio InP membranes. The grown Co nanowires are polycrystalline with a very small grain size. They show a narrow hysteresis loop with a preferential orientation of the easy magnetization direction along the long nanowire axis due to the arising shape anisotropy of the Co nanowires.

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

Science.gov (United States)

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

2014-10-10

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

Effect of solid lubricants on friction and wear behaviour of alloyed ...

Indian Academy of Sciences (India)

Friction and wear behaviour of MoS2, boric acid, graphite and TiO2 at four different sliding speeds (1.0, 1.5, 2.0, 2.5 m/s) has been compared with dry sliding condition. MoS2 and graphite show 30 to 50% reduction in mass loss compared to other lubricants at all sliding speeds. Friction coefficient reduces with increase in ...

Analytical and sampling problems in primary coolant circuits of PWR-type reactors

International Nuclear Information System (INIS)

Illy, H.

1980-10-01

Details of recent analytical methods on the analysis and sampling of a PWR primary coolant are given in the order as follows: sampling and preparation; analysis of the gases dissolved in the water; monitoring of radiating substances; checking of boric acid concentration which controls the reactivity. The bibliography of this work and directions for its use are published in a separate report: KFKI-80-48 (1980). (author)

X-ray fluorescence analysis of Fe, Mn, Cr and V in natural silicate crystals

International Nuclear Information System (INIS)

Dias, O.L.; Albuquerque, A.R.P.L.; Isotani, S.

1983-01-01

Concentrations of Fe, Mn, Cr and V were determined in samples of beryl, topaze, tourmaline and spodumene by measuring the first order Kα fluorescence lines. The intensity of these lines were calibrated by using beryl as the standard matrix. The matrices were prepared in the form of pressed pellets with 4:1 mixture of beryl and boric acid, where transition metal oxides were added. (Author) [pt

Carbon Nanotube Fiber Pretreatments for Electrodeposition of Copper

OpenAIRE

Hannula, Pyry-Mikko; Junnila, Minttu; Janas, Dawid; Aromaa, Jari; Forsén, Olof; Lundström, Mari

2018-01-01

There is increasing interest towards developing carbon nanotube-copper (CNT-Cu) composites due to potentially improved properties. Carbon nanotube macroscopic materials typically exhibit high resistivity, low electrochemical reactivity, and the presence of impurities, which impede its use as a substrate for electrochemical deposition of metals. In this research, different CNT fiber pretreatment methods, such as heat treatment, immersion in Watts bath, anodization, and exposure to boric acid (...

Selections From Kung-Jen JIH-PAO (Source Span: 9 May-30 June 1961) Number 7 -Communist China.

Science.gov (United States)

1961-08-17

sulphate Ammonium hydrogen carbonate Sodium borate Titaniüm-iron powder Sodium fluoride Silicon dioxide Barium chloride beryllium carbonate ...Vinzenstrasse, 22a :■ P. 0. Box 3521 Aachen, Germany Washington 7> B.C. , Institute de Sociologie Solvay Rue du Chatelain, k9 Brussels, Belgium State... Sodium nitrite Specifications Pure n industrial Boric Acid " A^ua ammonia " Magnesium sulphate Industrial Manganese tedroxide Pure

Recent bibliography on analytical and sampling problems of a PWR primary coolant Suppl. 4

International Nuclear Information System (INIS)

Illy, H.

1986-09-01

The 4th supplement of a bibliographical series comprising the analytical and sampling problems of the primary coolant of PWR type reactors covers the literature from 1985 up to July 1986 (220 items). References are listed according to the following topics: boric acid; chloride, chlorine; general; hydrogen isotopes; iodine; iodide; noble gases; oxygen; other elements; radiation monitoring; reactor safety; sampling; water chemistry. (V.N.)

The comparison of possibilities at using of different electrolytes in the process of anodizing aluminum

Directory of Open Access Journals (Sweden)

M. Gombar

2014-01-01

Full Text Available The contribution researches and solves the suitability of utilize of electrolyte, consisting of the oxalic acid, boric acid, sodium chloride and aluminium cations in the process of anodizing aluminium in operating conditions of electrolyte T = 22 °C, t = time of oxidation and the size of at least 210 an applied voltage U = 12 V. The appropriate use of the electrolyte is judged by the thickness of the anodic aluminium oxide layer (AAO formed on the basis of the monitoring and the resulting quality of the sample surface.

Catalytic agents; motor fuels

Energy Technology Data Exchange (ETDEWEB)

1935-09-16

The anti-knock qualities of benzines are improved by passing them in the vapor phase and at temperatures below which cracking takes place over catalysts comprising phosphates. A Mexican straight run gasoline (octane no. 55) is passed at 450/sup 0/C over granular boron phosphate. A product having an octane number of 62.5 is obtained without loss due to formation of gases. The boron phosphate was prepared by heating on a steam bath orthophosphoric acid and boric acid in the ratio corresponding to the compound BPO/sub 4/.

Efeito de produtos alternativos para o controle do bolor verde (Penicillium digitatum em pós-colheita de citros Effect of the alternative products for control of green mold (Penicillium digitatum in post-harvest citrus fruit

Directory of Open Access Journals (Sweden)

DANIEL ANDRADE DE SIQUEIRA FRANCO

2002-08-01

Full Text Available O objetivo do trabalho foi verificar a ocorrência de sinergismo entre misturas de produtos alternativos aos fungicidas, para o controle do bolor verde (Penicillium digitatum em pós-colheita de citros. Foram testados dez produtos individualmente e trinta e cinco combinações destes produtos dois a dois, em comparação com tiabendazole e testemunha, com e sem inoculação. Os produtos testados não apresentaram efeito de sinergismo, exceto a mistura carbonato de Na + ácido bórico. Carbonato de Na e ácido bórico controlaram a doença em 78 e 87%, respectivamente, e, utilizando a mistura, o controle foi de 93%. Destacaram-se, ainda no controle da doença, o bicarbonato de Na, metabissulfito de Na e as misturas de bicarbonato de sódio + ácido bórico, carbonato de Na + carbonato de K, carbonato de Na + sorbato de K, bicarbonato de Na + carbonato de Na, controlando 92; 77; 81; 77; 75 e 71%, respectivamente. O tiabendazole utilizado como padrão controlou totalmente a doença.The objective of this work was verify the ocurrence of synergism of mixtures for alternative products to the fungicides for the control of the green mold (Penicillium digitatum in post-harvest citrus fruits. The efficiency of ten products, tested individually, and thirty five combinations among them, in pairs, were compared to thiabendazole and control, with and without inoculation. The products didn't present a synergism effect, except the mixture sodium carbonate + boric acid, that had a disease control of 93%. The products, sodium carbonate and boric acid controled 78 and 87%, respectively. The sodium bicarbonate, sodium methabisulphite and the mixtures of sodium bicarbonate + boric acid, sodium carbonate + potassium carbonate, sodium carbonate + potassium sorbate, sodium bicarbonate + sodium carbonate had a disease control of 92%, 77%, 81%, 77%, 75% and 71%, respectively. The fungicide treatment with thiabendazole used by standard had a whole disease control.

SUN family proteins Sun4p, Uth1p and Sim1p are secreted from Saccharomyces cerevisiae and produced dependently on oxygen level.

Directory of Open Access Journals (Sweden)

Evgeny Kuznetsov

Full Text Available The SUN family is comprised of proteins that are conserved among various yeasts and fungi, but that are absent in mammals and plants. Although the function(s of these proteins are mostly unknown, they have been linked to various, often unrelated cellular processes such as those connected to mitochondrial and cell wall functions. Here we show that three of the four Saccharomyces cerevisiae SUN family proteins, Uth1p, Sim1p and Sun4p, are efficiently secreted out of the cells in different growth phases and their production is affected by the level of oxygen. The Uth1p, Sim1p, Sun4p and Nca3p are mostly synthesized during the growth phase of both yeast liquid cultures and colonies. Culture transition to slow-growing or stationary phases is linked with a decreased cellular concentration of Sim1p and Sun4p and with their efficient release from the cells. In contrast, Uth1p is released mainly from growing cells. The synthesis of Uth1p and Sim1p, but not of Sun4p, is repressed by anoxia. All four proteins confer cell sensitivity to zymolyase. In addition, Uth1p affects cell sensitivity to compounds influencing cell wall composition and integrity (such as Calcofluor white and Congo red differently when growing on fermentative versus respiratory carbon sources. In contrast, Uth1p is essential for cell resistance to boric acids irrespective of carbon source. In summary, our novel findings support the hypothesis that SUN family proteins are involved in the remodeling of the yeast cell wall during the various phases of yeast culture development and under various environmental conditions. The finding that Uth1p is involved in cell sensitivity to boric acid, i.e. to a compound that is commonly used as an important antifungal in mycoses, opens up new possibilities of investigating the mechanisms of boric acid's action.

Efeito da adubação com boro e esterco bovino sobre a produtividade da figueira e as propriedades químicas do solo Effect of boron and cattle manure fertilization on yield productivity fig tree and on soil properties

Directory of Open Access Journals (Sweden)

Luiz Carlos Santos Caetano

2006-08-01

Full Text Available O objetivo deste trabalho foi verificar o efeito da adubação da cultura da figueira com boro e esterco bovino sobre a produtividade de figos verdes e as propriedades químicas do solo. Os tratamentos foram cinco doses de ácido bórico (0, 20, 40, 60 e 100g planta-1 combinadas com dois níveis de adubação de esterco (sem esterco e 10kg de esterco/planta. O delineamento experimental foi o de blocos casualizados em esquema de parcelas subdivididas e quatro repetições. A adubação com ácido bórico não afetou a produtividade de figos, enquanto que o esterco bovino aumentou-a. Os teores de fósforo e potássio no solo aumentaram significativamente e o teor de alumínio diminuiu significativamente em função da adubação com esterco bovino. O teor de B no solo, extraído pelo método da água quente, aumentou linearmente em função das doses de ácido bórico.The objective of the present work was evaluate the effect of fig tree orchard fertilization with boron and cattle manure on the green fig yield and soil chemical properties. The treatments were five boric acid levels (0, 20, 40, 60 and 100g plant-1 combined with two cattle manure fertilization levels (without cattle manure and 10kg of cattle manure/plant. The experimental design was that of randomized blocks in a split-plot scheme and four repetitions. The boric acid fertilization did not affect the fig productivity whereas the cattle manure one increased it. The P and K content increased significantly and the Al content decreased significantly in function of the cattle manure fertilization. The B soil content, extracted by hot water methodology increased linearly in function of the boric acid levels.

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

Science.gov (United States)

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

2014-01-01

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

Anodizing of aluminum with improved corrosion properties

International Nuclear Information System (INIS)

John, P.; Khan, I.U.

2010-01-01

Anodizing of aluminum was studied in sulphuric/oxalic/boric acid electroiyte system. The corrosion resistance of the anodic oxide coating of aluminum was determined by potentiodynamic polarization test and scanning electron microscope (SEM) was used to investigate the surface morphology before and after corrosion test. It was found that the oxide coating obtained by this method showed better corrosion resistance with no significant difference in surface morphology. (author)

X-ray fluorescence analysis of Fe, Mn, Cr and V in natural silicate crystals

International Nuclear Information System (INIS)

Dias, O.L.; Albuquerque, A.R.P.L.; Isotani, S.

1983-04-01

Concentrations of Fe, Mn, Cr and V were determined in samples of beryl, topaz, tourmaline and spodumene by measuring the first order K sub(α) fluorescence lines. The intensity of these lines were calibrated by using beryl as the standard matrix. The matrices were prepared in the form of pressed pellets with 4:1 mixture of beryl and boric acid, where transition metal oxides were added. (Author) [pt

Enhancing resistance to burnout via coolant chemistry

Energy Technology Data Exchange (ETDEWEB)

Tu, J. P.; Dinh, T. N.; Theofanous, T. G. [Univ. of California, Santa Barbara (United States)

2003-07-01

Boiling Crisis (BC) on horizontal, upwards-facing copper and steel surfaces under the influence of various coolant chemistries relevant to reactor containment waters is considered. In addition to Boric Acid (BA) and TriSodium Phosphate (TSP), pure De-Ionized Water (DIW) and Tap Water (TW) are included in experiments carried out in the BETA facility. The results are related to a companion paper on the large scale ULPU facility.

Scoria analysis by X-ray fluorescence with briquet

International Nuclear Information System (INIS)

Silva, G.R. da; Albert, P.E.

1987-01-01

The sample of scoria is triturated, using boric acid as agglomerative. The briquets are analyzed by X-ray quantometry, establishing the proportions of SiO 2 , P 2 O 5 , S, Cr 2 O 3 , V 2 O 5 , TiO 2 , Al 2 O 3 , Mg O, Ca O, FeO and their basicity. The calibration curves are prepared with standard scoria samples, by chemical analysis. (C.G.C.) [pt

Proceedings of the specialists' workshop on iodine chemistry in reactor safety, September 11th and 12th, 1985 at AERE, Harwell, England

International Nuclear Information System (INIS)

Deane, A.M.; Potter, P.E.

1986-01-01

The iodine workshop, held at Harwell in Sept. 1985, provided a forum to study the chemistry of iodine under reactor accident conditions. The major issues discussed were iodine equilibrium and kinetics in aqueous solutions, radiolysis of iodine in aqueous solutions, iodine/boric acid reactions, organic iodine compounds and partition measurements. Other factors must be identified before a complete model of iodine behaviour during reactor accidents can be established. (U.K.)

Safety analysis of increase in heat removal from reactor coolant system with inadvertent operation of passive residual heat removal at no load conditions

Energy Technology Data Exchange (ETDEWEB)

Shao, Ge; Cao, Xuewu [School of Mechanical and Engineering, Shanghai Jiao Tong University, Shanghai (China)

2015-06-15

The advanced passive pressurized water reactor (PWR) is being constructed in China and the passive residual heat removal (PRHR) system was designed to remove the decay heat. During accident scenarios with increase of heat removal from the primary coolant system, the actuation of the PRHR will enhance the cooldown of the primary coolant system. There is a risk of power excursion during the cooldown of the primary coolant system. Therefore, it is necessary to analyze the thermal hydraulic behavior of the reactor coolant system (RCS) at this condition. The advanced passive PWR model, including major components in the RCS, is built by SCDAP/RELAP5 code. The thermal hydraulic behavior of the core is studied for two typical accident sequences with PRHR actuation to investigate the core cooling capability with conservative assumptions, a main steam line break (MSLB) event and inadvertent opening of a steam generator (SG) safety valve event. The results show that the core is ultimately shut down by the boric acid solution delivered by Core Makeup Tank (CMT) injections. The effects of CMT boric acid concentration and the activation delay time on accident consequences are analyzed for MSLB, which shows that there is no consequential damage to the fuel or reactor coolant system in the selected conditions.

Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions

KAUST Repository

Alpatova, Alla; Alsaadi, Ahmad Salem; Ghaffour, NorEddine

2018-01-01

The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO scaling on the membrane surface.

Assessment of pressurized water reactor control rod drive mechanism nozzle cracking

International Nuclear Information System (INIS)

Shah, V.N.; Ware, A.G.; Porter, A.M.

1994-10-01

This report surveys the field experience related to cracking of pressurized water reactor (PWR) control rod drive mechanism nozzles (Alloy 600 material); evaluates design, fabrication, and operating conditions for the nozzles in US PWR; and evaluates the safety significance of nozzle cracking. Inspection at 78 overseas and one US PWR has revealed mainly axial cracks in 101 nozzles. The cracking is caused by primary water stress corrosion cracking, which requires the simultaneous presence of high tensile stresses, high operating temperatures, and susceptible microstructure. CRDM nozzle cracking is not a short-term safety issue. An axial crack is not likely to grow above the vessel head to a critical length because the stresses are not high enough to support the growth away from the attachment weld. Primary coolant leaking through an axial crack could cause a short circumferential crack on the outside surface. However, this crack is not likely to propagate through the nozzle wall to cause rupture. Leakage of the primary coolant from a through-wall crack could cause boric acid corrosion of the vessel head and challenge the structural integrity of the head, but it is very unlikely that the accumulated deposits of boric acid crystals resulting from such leakage could remain undetected

Photochemistry of peroxoborates: borate inhibition of the photodecomposition of hydrogen peroxide.

Science.gov (United States)

Rey, Sébastien; Davies, D Martin

2006-12-13

The UV absorbance and photochemical decomposition kinetics of hydrogen peroxide in borate/boric acid buffers were investigated as a function of pH, total peroxide concentration, and total boron concentration. At higher pH borate/boric acid inhibits the photodecomposition of hydrogen peroxide (molar absorptivity and quantum yield of H(2)O(2) and HO(2) (-), (19.0+/-0.3) M(-1) cm(-1) and 1, and (237+/-7) M(-1) cm(-1) and 0.8+/-0.1, respectively). The results are consistent with the equilibrium formation of the anions monoperoxoborate, K(BOOH)=[H(+)][HOOB(OH)(3) (-)]/([B(OH)(3)][H(2)O(2)]), 2.0 x 10(-8), R. Pizer, C. Tihal, Inorg. Chem. 1987, 26, 3639-3642, and monoperoxodiborate, K(BOOB)=[BOOB(2-)]/([B(OH)(4) (-)][HOOB(OH)(3) (-)]), 1.0+/-0.3 or 4.3+/-0.9, depending upon the conditions, with molar absorptivity, (19+/-1) M(-1) cm(-1) and (86+/-15) M(-1) cm(-1), respectively, and respective quantum yields, 1.1+/-0.1 and 0.04+/-0.04. The low quantum yield of monoperoxodiborate is discussed in terms of the slower diffusion apart of incipient (.)OB(OH)(3) (-) radicals than may be possible for (.)OH radicals, or a possible oxygen-bridged cyclic structure of the monoperoxodiborate.

Hygroscopicity and ammonia volatilization losses from nitrogen sources in coated urea

Directory of Open Access Journals (Sweden)

Letícia de Abreu Faria

2014-06-01

Full Text Available Hygroscopic fertilizers tend to absorb moisture from the air and may have undesirable characteristics such as moistness, clumping and lower fluidity, hampering the application. The increasing use of urea is due to its numerous advantages, although this nitrogen (N source is highly susceptible to volatilization losses, particularly when applied to the soil surface of management systems with conservation of crop residues. The volatilization losses can be minimized by slow or controlled-release fertilizers, with controlled water solubility of the urea-coating materials; and by stabilized fertilizers, which prolong the period during which N remains in the amide or ammonia forms by urease inhibitors. This study evaluated the hygroscopicity of and ammonia volatilization from urea coated with boric acid and copper sulfate or with sulfur. The hygroscopicity of the sources was evaluated over time after exposure to five levels of relative humidity (RH and volatilization evaluated after application to the soil surface covered with sugarcane trash. Ammonium nitrate has a low potential for volatilization losses, but is highly hygroscopic. Although coating with boric acid and copper sulfate or elemental sulfur reduced the critical humidity level of urea, the delay in the volatilization process is a potential positive factor.

The 10B(n,α)7Li reaction in PWR coolants: calculations of the effect on coolant pH and on decreases in 10B isotopic fractions

International Nuclear Information System (INIS)

Polley, M.V.

1988-07-01

Boron is used as a chemical shim in PWRs for reactivity control and is added in the form of boric acid to the primary coolant. The 10 B(n,α) 7 Li reaction leads to a continuous increase in 7 Li in the primary coolant and to a continuous decrease in 10 B the isotope of boron responsible for control of reactivity. The rate of increase in coolant pH due to 7 Li production is calculated for the Sizewell 'B' PWR to enable judgements to be made on the frequency of sampling and removal of lithium required to maintain the pH of the primary coolant within the desired limits. Calculations are contrasted for the cases of natural boron and 100% 10 B chemical shims, for both a normal cycle and an extended 18 month cycle. Calculations of 10 B depletion over 30 years of operation as a function of the quantity of boron discharged to waste are also presented. 10 B isotopic fractions are calculated for the reactor coolant (RC), boric acid tanks (BATs) and refuelling water storage tank (RWST) assuming rapid mixing of BAT and RC boron for tritium control and other reasons. Such predictions enable assessments of the reactor physics implications of 10 B consumption to be made. (author)

Development of a Long Term Cooling Analysis Methodology Using Rappel

International Nuclear Information System (INIS)

Lee, S. I.; Jeong, J. H.; Ban, C. H.; Oh, S. J.

2012-01-01

Since the revision of the 10CFR50.46 in 1988, which allowed BE (Best-Estimate) method in analyzing the safety performance of a nuclear power plant, safety analysis methodologies have been changed continuously from conservative EM (Evaluation Model) approaches to BE ones. In this context, LSC (Long-Term core Cooling) methodologies have been reviewed by the regulatory bodies of USA and Korea. Some non-conservatism and improperness of the old methodology have been identified, and as a result, USNRC suspended the approval of CENPD-254-P-A which is the old LSC methodology for CE-designed NPPs. Regulatory bodies requested to remove the non-conservatisms and to reflect system transient behaviors in all the LSC methodologies used. In the present study, a new LSC methodology using RELAP5 is developed. RELAP5 and a newly developed code, BACON (Boric Acid Concentration Of Nuclear power plant) are used to calculate the transient behavior of the system and the boric acid concentration, respectively. Full range of break spectrum is considered and the applicability is confirmed through plant demonstration calculations. The result shows a good comparison with the old-fashioned ones, therefore, the methodology could be applied with no significant changes of current LSC plans

Method of controlling the reactor operation

International Nuclear Information System (INIS)

Ishiguro, Akira; Nakakura, Hiroyuki.

1987-01-01

Purpose: To moderate vibratory response due to delayed operation thereby obtain stable controlled response in the operation control for a PWR type reactor. Method: the reactor operation is controlled by the axial power distribution control by regulating the boron concentration in primary coolants with a boron density control system and controlling the average temperature for the primary coolants with the control rod control system. In this case, the control operation and the control response become instable due to transmission delay, etc. of aqueous boric acid injection to the primary coolant circuits to result in vibratory response. In the present invention, signals are prepared by adding the amount in proportion to the variation coefficient with time of xenone concentration obtained from the measured value for the reactor power added to the conventional axial power distribution parameter deviation and used as the input signals for the boron concentration control system. As a result, the instability due to the transmission delay of the aqueous boric acid injection is improved by the preceding control by the amount in proportion with the variation coefficient with time of the xenone concentration. An advantageous effect can be expected for the load following operation during day time according to the present invention. (Kamimura, M.)

Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions

KAUST Repository

Alpatova, Alla

2018-03-26

The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO scaling on the membrane surface.

Preliminary study on detection technology of the cladding weld of spent fuel storage pool

Science.gov (United States)

Qi, Pan; Cui, Hongyan; Feng, Meiming; Shao, Wenbin; Liao, Shusheng; Li, Wei

2018-04-01

As the first barrier of the Spent fuel storage pool, the steel cladding using different sizes (length×width) of 304L stainless steel with 3˜6mm thickness plate argon arc welded together which is direct contacted with boric acid water. Environmental humidity between the back of steel cladding and concrete, makes phosphate, chloride ion overflowed from the concrete that corroded on the weld zone with different mechanism. Part of the corrosion defects can penetrate leaded to leakage of boric acid water in penetration position accelerated crack propagation. In view of the above situation and combined with the actual needs of the power plant, the development of effective underwater nondestructive testing means of the weld area for periodic inspection and monitoring is necessary. A single method may lead to the missing of defects detection due to weld reinforcement unpolished. In this paper, eddy current array (ARRAY) and Alternating Current Field Measurement (ACFM) are adapted to test the limit sensitivity and resolution through by the specimens with artificial defects which make their detection abilities close to satisfy engineering requirements. The preliminary study found that Φ0.5mm through-wall hole and with 2mm length and 0.3mm width through-wall crack in the weld can be good inspected.

Determination of Cd, Pb and As in sediments of the Sava River by electrothermal atomic absorption spectrometry

Directory of Open Access Journals (Sweden)

SIMONA MURKO

2010-01-01

Full Text Available The applicability of nitric acid, palladium nitrate and a mixture of palladium and magnesium nitrate as matrix modifiers were estimated for the accurate and reproducible determination of cadmium (Cd, lead (Pb and arsenic (As in sediments of the Sava River by electrothermal atomic absorption spectrometry, ETAAS. Decomposition of the samples was done in a closed vessel microwave-assisted digestion system using nitric, hydrochloric and hydrofluoric acids, followed by the addition of boric acid to convert the fluorides into soluble complexes. The parameters for the determination of Cd, Pb and As in sediments were optimised for each individual element and for each matrix modifier. In addition, two sediment reference materials were also analysed. In determination of Cd and Pb, nitric acid was found to be the most appropriate matrix modifier. The accurate and reliable determination of Cd and Pb in sediments was possible also in the presence of boric acid. The use of a mixture of palladium and magnesium nitrate efficiently compensated for matrix effects and enabled the accurate and reliable determination of As in the sediments. Quantification of Cd and As was performed by calibration using acid matched standard solutions, while the standard addition method was applied for the quantification of Pb. The repeatability of the analytical procedure for the determination of Cd, Pb and As in sediments was ±5 % for Cd, ±4 % for Pb and ±2 % for As. The LOD values of the analytical procedure were found to be 0.05 mg/kg for Cd and 0.25 mg/kg for Pb and As, while the LOQ values were 0.16 mg/kg for Cd and 0.83 mg/kg for Pb and As. Finally, Cd, Pb and As were successfully determined in sediments of the Sava River in Slovenia.

Pelleted waste form for high-level ICPP wastes

International Nuclear Information System (INIS)

Lamb, K.M.; Priebe, S.J.; Cole, H.S.; Taki, B.D.

1979-01-01

Simulated zirconia type calcined waste is pelletized on a 41-cm dia disc pelletizer using 5% bentonite, 2% metakaolin, and 2% boric acid as a solid binder and 7M phosphoric plus 4M nitric acid as a liquid binder. After heat treatment at 800 0 C for 2 hours, the pellets are impact resistant and have a leach resistance of 10 -4 g/cm 2 /day, based on Soxhlet leaching for 100 hours at 95 0 C with distilled water. An integrated pilot plant is being fabricated to verify the process. 1 figure, 4 tables

Pelleted waste form for high-level ICPP wastes

International Nuclear Information System (INIS)

Lamb, K.M.; Priebe, S.J.; Cole, H.S.; Taki, B.d.

1979-01-01

Simulated zirconia-type calcined waste is pelletized on a 41-cm diameter disc pelletizer using 5% bentonite, 2% metakaolin, and 2% boric acid as a solid binder and 7M phosphoric plus 4M nitric acid as a liquid binder. After heat treatment at 800 0 C for 2 hours the pellets are impact resistant and have a leach resistance of 10 -4 g/cm 2 . day, based on Soxhlet leaching for 100 hours at 95 0 C with distilled water. An integrated pilot plant is being fabricated to verify the process. 1 figure, 4 tables

Deposition of hematite particles on alumina seal faceplates of nuclear reactor coolant pumps: Laboratory experiments and industrial feedback

OpenAIRE

Lefèvre, Grégory; Živković, Ljiljana S.; Jaubertie, Anne

2012-01-01

In the primary circuit of pressurized water reactors (PWR), the dynamic sealing system in reactor coolant pumps is ensured by mechanical seals whose ceramic parts are in contact with the cooling solution. During the stretch-out phase in reactor operation, characterized by low boric acid concentration, the leak-off flow has been observed to abnormally evolve in industrial plants. The deposition of hematite particles, originating from corrosion, on alumina seals of coolant pumps is suspec...

Determination of 59Ni in radioactive waste

International Nuclear Information System (INIS)

Fisera, O.; Sebesta, F.

2010-01-01

Composite material PAN-DMG, containing chelating agent dimethylglyoxime (DMG) immobilized in porous matrix of binding polymer polyacrylonitrile (PAN), was used for nickel separation and concentration. Method for preparation of 59 Ni source for low energy photon spectrometry was developed using homogeneous precipitation of nickel with DMG. The proposed method was tested with two types of real radioactive waste (boric acid concentrate from nuclear power plant (NPP) evaporator and spent ion exchanger from NPP). (author)

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

Science.gov (United States)

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

2014-07-21

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

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

Indian Academy of Sciences (India)

Unknown

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

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

International Nuclear Information System (INIS)

Yoo, Jae Woon

1997-02-01

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

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)

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

Indian Academy of Sciences (India)

Unknown

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

Highly water soluble nanoparticles as a draw solute in forward osmosis for the treatment of radioactive liquid waste

International Nuclear Information System (INIS)

Yang, Heeman; Choi, Hye Min; Jang, Sungchan; Seo, Bumkyoung; Lee, Kune Woo; Moon, Jei Kwon

2014-01-01

. In this study, we introduced highly water-soluble hyperbranched caroboxylated polyglycerol-coated magnetic nanoparticles (CPG-MNPs). It is known that the highly branched, globular architecture of PG significantly increase solubility compared to linear polymer and they are eco-friendly. The CPG-MNPs showed no aggregate of particles in water even after placing external magnet, and exhibited a high water flux in FO process. The CPG-MNPs are, therefore, potentially useful as a draw solute in FO processes. The operation of nuclear pressurized water reactors (PWRs) results in numerous radioactive waste streams which vary in radioactivity content. Most PWR stations have experienced leakages of boric acid into liquid radioactive waste systems. These wastes contain about 0.3∼0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40∼90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. Forward osmosis (FO), a low energy technique based on membrane technologies, has recently garnered attention for its utility in wastewater treatment and desalination applications. In the FO process, water flows across a semi-permeable membrane from a solution with a low osmotic pressure (the feed solution) to a solution with a high osmotic pressure (the draw solution). The driving force in FO processes is provided by the osmotic gradient between the two solutions. Low energy costs and low degrees of membrane fouling are two of the advantages conveyed by FO processes over other processes, such as reverse osmosis processes that rely on a hydraulic pressure driving force. However, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe3O4 nanoparticles can be separated from water by an external magnet field

Highly water soluble nanoparticles as a draw solute in forward osmosis for the treatment of radioactive liquid waste

Energy Technology Data Exchange (ETDEWEB)

Yang, Heeman; Choi, Hye Min; Jang, Sungchan; Seo, Bumkyoung; Lee, Kune Woo; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

. In this study, we introduced highly water-soluble hyperbranched caroboxylated polyglycerol-coated magnetic nanoparticles (CPG-MNPs). It is known that the highly branched, globular architecture of PG significantly increase solubility compared to linear polymer and they are eco-friendly. The CPG-MNPs showed no aggregate of particles in water even after placing external magnet, and exhibited a high water flux in FO process. The CPG-MNPs are, therefore, potentially useful as a draw solute in FO processes. The operation of nuclear pressurized water reactors (PWRs) results in numerous radioactive waste streams which vary in radioactivity content. Most PWR stations have experienced leakages of boric acid into liquid radioactive waste systems. These wastes contain about 0.3∼0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40∼90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. Forward osmosis (FO), a low energy technique based on membrane technologies, has recently garnered attention for its utility in wastewater treatment and desalination applications. In the FO process, water flows across a semi-permeable membrane from a solution with a low osmotic pressure (the feed solution) to a solution with a high osmotic pressure (the draw solution). The driving force in FO processes is provided by the osmotic gradient between the two solutions. Low energy costs and low degrees of membrane fouling are two of the advantages conveyed by FO processes over other processes, such as reverse osmosis processes that rely on a hydraulic pressure driving force. However, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe3O4 nanoparticles can be separated from water by an external magnet field

Synthesis, characterization, molecular docking and in vitro antimalarial properties of new carboxamides bearing sulphonamide.

Science.gov (United States)

Ugwu, D I; Okoro, U C; Ukoha, P O; Okafor, S; Ibezim, A; Kumar, N M

2017-07-28

Sulphonamides and carboxamides have shown large number of pharmacological properties against different types of diseases among which is malaria. Twenty four new carboxamide derivatives bearing benzenesulphonamoyl alkanamides were synthesized and investigated for their in silico and in vitro antimalarial and antioxidant properties. The substituted benzenesulphonyl chlorides (1a-c) were treated with various amino acids (2a-h) to obtain the benzenesulphonamoyl alkanamides (3a-x) which were subsequently treated with benzoyl chloride to obtain the N-benzoylated derivatives (5a-f, i-n and q-v). Further reactions of the N-benzoylated derivatives or proline derivatives with 4-aminoacetophenone (6) using boric acid as a catalyst gave the sulphonamide carboxamide derivatives (7a-x) in excellent yields. The in vitro antimalarial studies showed that all synthesized compounds had antimalarial property. Compound 7k, 7c, 7l, 7s, and 7j had mean MIC value of 0.02, 0.03, 0.05, 0.06 and 0.08 μM respectively comparable with chloroquine 0.06 μM. Compound 7c was the most potent antioxidant agent with IC 50 value of 0.045 mM comparable with 0.34 mM for ascorbic acid. In addition to the successful synthesis of the target molecules using boric acid catalysis, the compounds were found to have antimalarial and antioxidant activities comparable with known antimalarial and antioxidant drugs. The class of compounds reported herein have the potential of reducing oxidative stress arising from malaria parasite and chemotherapeutic agent used in the treatment of malaria. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Separation of boron isotopes by ion exchange chromatography: studies with Duolite-162, a type-II resin

International Nuclear Information System (INIS)

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

1994-01-01

The selection of resin plays an important role in the process of separation of boron isotopes by ion exchange chromatography. The determination of (i) ion exchange capacity of Duolite-162 resin for hydroxyl - chloride exchange, (ii) hydroxyl - borate exchange, (iii) isotopic exchange separation factor by batch method and (iv) effect of concentration of boric acid on isotopic exchange separation factor to test the suitability of the above resin for this process are discussed in this report. (author)

Influence of cathodic current density and mechanical stirring on the electrodeposition of Cu-Co alloys in citrate bath

OpenAIRE

Leandro Trinta de Farias; Aderval Severino Luna; Dalva Cristina Baptista do Lago; Lilian Ferreira de Senna

2008-01-01

Cathodic polarization curves of Cu-Co alloys were galvanostatically obtained on a platinum net, using electrolytes containing copper and cobalt sulfates, sodium citrate and boric acid (pH values ranging from 4.88 to 6.00), with different mechanical stirring conditions. In order to evaluate quantitatively the influence of the applied current density and the mechanical stirring on the cathodic efficiency, the alloy composition for the Cu-Co alloy deposition process, and the average deposition p...

Recent bibliography on analytical and sampling problems of a PWR primary coolant

International Nuclear Information System (INIS)

Illy, H.

1980-07-01

An extensive bibliography on the problems of analysis and sampling of the primary cooling water of PWRs is presented. The aim was to collect the analytical methods for dissolved gases. The sampling and preparation are also taken into account. last 8-10 years is included. The bibliography is arranged into alphabetical order by topics. The most important topics are as follows: boric acid, gas analysis, hydrogen isotopes, iodine, noble gases, radiation monitoring, sampling and preparation, water chemistry. (R.J.)

Complexometric determination of scandium and aluminium

International Nuclear Information System (INIS)

Tikhonov, V.N.

1980-01-01

Described is the complexometric determination of scandium and aluminium by the method of reverse titration of EDTA excess by indium salt solution in the presence of the xylenol orange indicator. For the method selectivity increase fluorides are used as a camouflage substance at low pH values (2.5-3.0). The excess fluoride-ions preventing titration are bound by boric acid. Y, Tb, Ti, Zr, Cu, Zn, V, Mo, Co, Cr prevent the determination of Sc and Al

Controls on the pH of hyper-saline lakes - A lesson from the Dead Sea

Science.gov (United States)

Golan, Rotem; Gavrieli, Ittai; Ganor, Jiwchar; Lazar, Boaz

2016-01-01

The pH of aqueous environments is determined by the dominant buffer systems of the water, defined operationally as total alkalinity (TA). The major buffer systems in the modern ocean are carbonic and boric acids of which the species bicarbonate, carbonate and borate make up about 77%, 19% and 4% of the TA, respectively. During the course of seawater evaporation (e.g. lagoons) the residual brine loses considerable portion of the dissolved inorganic carbon (DIC) and carbonate alkalinity (CA) already at the early stages of evaporation. DIC and CA decrease due to massive precipitation of CaCO3, while total boron (TB) increases conservatively, turning borate to the dominant alkalinity species in marine derived brines. In the present work we assess the apparent dissociation constant value of boric acid (KB‧) in saline and hypersaline waters, using the Dead Sea (DS) as a case study. We explain the DS low pH (∼6.3) and the effect of the boric and carbonic acid pK‧-s on the behavior of the brine's buffer system, including the pH increase that results from brine dilution. The KB‧ in DS was estimated from TB, TA, DIC and pH data measured in this study and early empirical data on artificial DS brines containing just carbonic acid. The KB‧ value was corroborated by Pitzer ion interaction model calculations using PHREEQC thermodynamic code applied to the chemical composition of the DS. Our results show that KB‧ increases considerably with the brine's ionic strength, reaching in the DS to a factor of 100 higher than in ;mean; seawater. Based on theoretical calculations and analyses of other natural brines it is suggested that brines' composition is a major factor in determining the KB‧ value and in turn the pH of such brines. We show that the higher the proportion of divalent cations in the brine the higher the dissociation constants of the weak acids (presumably due to formation of complexes). The low pH of the Dead Sea is accordingly explained by its extremely

Boron reclamation

International Nuclear Information System (INIS)

Smith, R.M.

1980-07-01

A process to recover high purity 10 B enriched crystalline boron powder from a polymeric matrix was developed on a laboratory basis and ultimately scaled up to production capacity. The process is based on controlled pyrolysis of boron-filled scrap followed by an acid leach and dry sieving operation to return the powder to the required purity and particle size specifications. Typically, the recovery rate of the crystalline powder is in excess of 98.5 percent, and some of the remaining boron is recovered in the form of boric acid. The minimum purity requirement of the recovered product is 98.6 percent total boron

Inverse-Frontal Chromatography studies on enrichment of Boron-10 using quaternery 4-vinylpyridine-divinylbenzene resin

International Nuclear Information System (INIS)

Bejawada, Venki; Mohapatra, C.; Rao, A.S.; Prasad, K.L.; Murthy, P.K.; Rao, A.K.; Singh, H.P.; Vithal, G.K.; Kumar, Sangita D.

2014-01-01

In order to enrich 10 B, band migration of boric acid-mannitol with hydrochloric acid solution was performed by inverse frontal chromatography on a porous, 25% crosslinked, 38% quaternized 4-vinylpyridine-divinylbenzene resin (py-resin). The work was initiated to replace the existing strong base anion exchange resin type-II (SBA-II) which is used in Boron Enrichment Plant (BEP) of heavy water plant Manuguru. Before its application in BEP, it is mandatory to evaluate py-resin for its performance. The studies showed that maximum of 40% 10 B enrichment observed after 13 m band movement and there was no further improvement, hence profile sampling carried out after 28 m. (author)

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

Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions.

Science.gov (United States)

Alpatova, A; Alsaadi, A; Ghaffour, N

2018-06-05

The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO 3 scaling on the membrane surface. Copyright © 2018 Elsevier B.V. All rights reserved.

Green synthesis of boron doped graphene and its application as high performance anode material in Li ion battery

International Nuclear Information System (INIS)

Sahoo, Madhumita; Sreena, K.P.; Vinayan, B.P.; Ramaprabhu, S.

2015-01-01

Graphical abstract: Boron doped graphene (B-G), synthesized by simple hydrogen induced reduction technique using boric acid as boron precursor, have more uneven surface as a result of smaller bonding distance of boron compared to carbon, showed high capacity and high rate capability compared to pristine graphene as an anode material for Li ion battery application. - Abstract: The present work demonstrates a facile route for the large-scale, catalyst free, and green synthesis approach of boron doped graphene (B-G) and its use as high performance anode material for Li ion battery (LIB) application. Boron atoms were doped into graphene framework with an atomic percentage of 5.93% via hydrogen induced thermal reduction technique using graphite oxide and boric acid as precursors. Various characterization techniques were used to confirm the boron doping in graphene sheets. B-G as anode material shows a discharge capacity of 548 mAh g −1 at 100 mA g −1 after 30th cycles. At high current density value of 1 A g −1 , B-G as anode material enhances the specific capacity by about 1.7 times compared to pristine graphene. The present study shows a simplistic way of boron doping in graphene leading to an enhanced Li ion adsorption due to the change in electronic states

Limited oxygen index levels of impregnated Scots pine wood

International Nuclear Information System (INIS)

Tomak, Eylem Dizman; Cavdar, Ayfer Donmez

2013-01-01

Highlights: • Scots pine samples were treated with 4 wood preservatives with various concentrations. • Limited oxygen index level was evaluated both for leached and un-leached samples. • All treatments improved fire retardance of samples despite some chemicals leached out. • Samples treated with fireproof agent showed the best results. • LOI of samples treated with boron powder and silicon oil was not changed by leaching. - Abstract: In this study, effect of various concentrations of boron powder, mixture of boric acid and borax, fireproof agent based on liquid blend of limestone, and silicon oil on limited oxygen index levels (LOI) of S. pine wood was investigated. Wood samples were first vacuum treated with the preservatives, and then were subjected to leaching procedure. Samples treated with fireproof agent showed the best results for improving the fire retardancy of wood, furthermore, samples treated with 25%, 50% and 100% of the solution did not burn. Leaching did not considerably change the LOI of wood samples treated with boron powder and silicon oil; however, LOI levels of samples treated with the mixture of boric acid and borax and fireproof agent were affected by leaching procedure probably arising those preservatives did not chemically bond to main wood components. All treatments improved fire retardancy of samples despite some amount of preservatives leached out from wood

Stereoselective separation of β-adrenergic blocking agents containing two chiral centers by countercurrent chromatography.

Science.gov (United States)

Lv, Liqiong; Bu, Zhisi; Lu, Mengxia; Wang, Xiaoping; Yan, Jizhong; Tong, Shengqiang

2017-09-01

Four β-adrenergic blocking agents, including 1-[(1-methylethyl)amino]-3-phenoxy-2-propanol (1), 1-[(1-methylethyl)amino]-3-(3-methylphenoxy)-2-propanol (2), 1,1'-[1,4-phenylenebis(oxy)]bis[3-[(1-methylethyl)amino]-2-propanol (3) and 1,1'-[(4-methyl-1,2-phenylene)bis(oxy)]bis[3-[(1-methylethyl)amino]-2-propanol (4), were stereoselectively separated by countercurrent chromatography using di-n-hexyl l-tartrate and boric acid as chiral selector. The compounds (3) and (4) have four optical isomers since they contained two chiral centers. A two-phase solvent system composed of chloroform-0.05molL -1 of acetate buffer containing 0.10molL -1 of boric acid (1:1, v/v) was selected, in which 0.10molL -1 of di-n-hexyl l-tartrate was added in the organic phase as chiral selector. 20-42mg of each racemate was stereoselectively separated by countercurrent chromatography in a single run with high purity of 96-98%, and the recovery of each separated compound reached around 87-93%. This is the first time report on successful stereoselective separation of optical isomeric compounds containing two chiral centers by countercurrent chromatography. At the same time, a chiral stationary phase was screened for analytical stereoselective separation of compounds (3) and (4) by high performance liquid chromatography. Copyright © 2017 Elsevier B.V. All rights reserved.

Green synthesis of boron doped graphene and its application as high performance anode material in Li ion battery

Energy Technology Data Exchange (ETDEWEB)

Sahoo, Madhumita; Sreena, K.P.; Vinayan, B.P.; Ramaprabhu, S., E-mail: ramp@iitm.ac.in

2015-01-15

Graphical abstract: Boron doped graphene (B-G), synthesized by simple hydrogen induced reduction technique using boric acid as boron precursor, have more uneven surface as a result of smaller bonding distance of boron compared to carbon, showed high capacity and high rate capability compared to pristine graphene as an anode material for Li ion battery application. - Abstract: The present work demonstrates a facile route for the large-scale, catalyst free, and green synthesis approach of boron doped graphene (B-G) and its use as high performance anode material for Li ion battery (LIB) application. Boron atoms were doped into graphene framework with an atomic percentage of 5.93% via hydrogen induced thermal reduction technique using graphite oxide and boric acid as precursors. Various characterization techniques were used to confirm the boron doping in graphene sheets. B-G as anode material shows a discharge capacity of 548 mAh g{sup −1} at 100 mA g{sup −1} after 30th cycles. At high current density value of 1 A g{sup −1}, B-G as anode material enhances the specific capacity by about 1.7 times compared to pristine graphene. The present study shows a simplistic way of boron doping in graphene leading to an enhanced Li ion adsorption due to the change in electronic states.

Cobalt and organics removal effect using fiber filter/reverse osmosis combination process for LLRW from korean PWR NPP

International Nuclear Information System (INIS)

Park, S.M.; Yang, H.Y.; Song, M.J.

2001-01-01

Evaporation system for liquid radioactive waste process has been used in Korean PWR nuclear power plants. The system is the most desirable process for decontamination factor (DF) theoretically. However, during the operation of the system, various problems have been arising such as scaling, carry over, etc. Because these problems make DF low, advanced technologies for liquid radwaste process have been world widely developed instead of keeping evaporation system. The main goal of new technologies is ALARA, ease of operation, cost effectiveness and minimization of environmental effect. Korea Electric Power Corporation is currently developing a combined treatment process for liquid radwaste using Micro-filter, Ultra-filter, Reverse Osmosis (RO) membrane, etc for the purpose of partly enhancement of evaporator and of having an alternative liquid radwaste process system for new reactors. As a part of the above project, the feasibility study using the Rolled Fiber-Filter (RFF) and RO membrane has been carried out. This paper reports the results of lab-test from the combined process of the fiber filtration and RO membrane module for cobalt and organics removal. The study was especially focused on the boric acid permeation in the RO unit. Because boric acid occupies large volume of the final waste after evaporation process, the new technology such as RO process has to be studied on the boron process. (author)

Induction of chromosomal aberrations by neutron capture reactions

International Nuclear Information System (INIS)

Ikushima, Takaji

1993-01-01

Boron neutron capture reaction (B-NCR) has been practiced in the treatment of malignancies of the central nervous system and melanoma using a thermal neutron beam from the KUR. Because of the very large neutron absorption cross-section and high kinetic energy released, gadolinium (Gd-157) has been expected to be an another promising element for neutron capture therapy. The dose-response relationship was determined for the induction of chromosomal aberrations by neutron capture reactions by B-10 and Gd-157 in cultured mammalian cells. The cells were exposed to thermal neutron beam with and without B-10 enriched (97 atom %) boric acid or Gd-DTPA, and chromosome-type aberrations were analysed in the first metaphases following irradiation. The frequency of dicentrics and rings increased linearly with neutron fluence either in the presence or absence of B-10 boric acid, while the yield of chromosomal aberrations induced by Gd-NCR increased in a linear quadratic fashion as a function of dose as in γ-rayed cells. Survival curves for the cells exposed to thermal neutrons showed no shoulder irrespective of the loading of B-10, but Gd-NCR produced the survival curve with a small shoulder. The differential chromosomal response to B-NCR and Gd-NCR might reflect the difference in radiation quality generated from the two types of thermal neutron capture reaction. (J.P.N.)

One-step synthesis of shell/core structural boron and nitrogen co-doped graphitic carbon/nanodiamond as efficient electrocatalyst for the oxygen reduction reaction in alkaline media

International Nuclear Information System (INIS)

Liu, Xiaoxu; Wang, Yanhui; Dong, Liang; Chen, Xi; Xin, Guoxiang; Zhang, Yan; Zang, Jianbing

2016-01-01

Shell/core structural boron and nitrogen co-doped graphitic carbon/nanodiamond (BN-C/ND) non-noble metal catalyst has been synthesized by a simple one-step heat-treatment of the mixture with nanodiamond, melamine, boric acid and FeCl 3 . In the process of the surface graphitization of nanodiamond with catalysis by FeCl 3 , B and N atoms from the decomposition of boric acid and melamine were directly introduced into the graphite lattice to form B, N co-doped graphitic carbon shell, while the core still retained the diamond structure. Electrochemical measurements of the BN-C/ND catalyst show much higher electrocatalytic activities towards oxygen reduction reaction (ORR) in alkaline medium than its analogues doped with B or N alone (B-C/ND or N-C/ND). The high catalytic activity of BN-C/ND is attributed to the synergetic effect caused by co-doping of C/ND with B and N. Meanwhile, the BN-C/ND exhibits an excellent electrochemical stability due to the special shell/core structure. There is almost no alteration occurred in the cyclic voltammetry measurements for BN-C/ND before and after 5000 cycles. All experimental results prove that the BN-C/ND may be exploited as a potentially efficient and inexpensive non-noble metal cathode catalyst for ORR to substitute Pt-based catalysts in fuel cells.

Limited oxygen index levels of impregnated Scots pine wood

Energy Technology Data Exchange (ETDEWEB)

Tomak, Eylem Dizman, E-mail: eylemdizman@yahoo.com [Forest Industry Engineering Department, Faculty of Forestry, Bursa Technical University, 16200 Bursa (Turkey); Cavdar, Ayfer Donmez [Interior Architecture Department, Faculty of Architecture, Karadeniz Technical University, 61080 Trabzon (Turkey)

2013-12-10

Highlights: • Scots pine samples were treated with 4 wood preservatives with various concentrations. • Limited oxygen index level was evaluated both for leached and un-leached samples. • All treatments improved fire retardance of samples despite some chemicals leached out. • Samples treated with fireproof agent showed the best results. • LOI of samples treated with boron powder and silicon oil was not changed by leaching. - Abstract: In this study, effect of various concentrations of boron powder, mixture of boric acid and borax, fireproof agent based on liquid blend of limestone, and silicon oil on limited oxygen index levels (LOI) of S. pine wood was investigated. Wood samples were first vacuum treated with the preservatives, and then were subjected to leaching procedure. Samples treated with fireproof agent showed the best results for improving the fire retardancy of wood, furthermore, samples treated with 25%, 50% and 100% of the solution did not burn. Leaching did not considerably change the LOI of wood samples treated with boron powder and silicon oil; however, LOI levels of samples treated with the mixture of boric acid and borax and fireproof agent were affected by leaching procedure probably arising those preservatives did not chemically bond to main wood components. All treatments improved fire retardancy of samples despite some amount of preservatives leached out from wood.

Evaluation of tecniques for controlling UF6 release clouds in the GAT environmental chamber

International Nuclear Information System (INIS)

Lux, C.J.

1982-01-01

Studies designed to characterize the reaction between UF 6 and atmospheric moisture, evaluate environmental variables of UF 6 cloud formation and ultimate cloud fate, and UF 6 release cloud control procedure have been conducted in the 1200 cu. ft. GAT environmental chamber. In earlier chamber experiments, 30 separate UF 6 release tests indicated that variations of atmospheric conditions and sample sizes had no significant effect on UO 2 F 2 particle size distribution, release cloud formation, or cloud settling rates. During the past year, numerous procedures have been evaluated for accelerating UF 6 cloud knockdown in a series of 37 environmental chamber releases. Knockdown procedures included: coarse water spray; air jet; steam spray (electrostatically charged and uncharged); carbon dioxide; Freon-12; fine water mist (uncharged); boric acid mist (charged and uncharged); and an ionized dry air stream. UF 6 hydrolysis cloud settling rates monitored by a laser/powermeter densitometer, indicated the relative effectiveness of various cloud knockdown techniques. Electrostatically charged boric acid/water mist, and electrostatically ionized dry air were both found to be very effective, knocking down the UO 2 F 2 release cloud particles in two to five minutes. Work to adapt these knockdown techniques for use under field conditions is continuing, taking into account recovery of the released uranium as well as nuclear criticality constraints

Efeito da aplicação foliar de boro e zinco sobre a produção e os teores de SST e ATT dos frutos da Pereira-Japonesa e da pinheira Leaf spray fertilization of boron and zinc on production, SST and ATT in fruits of pear and sugar apple

Directory of Open Access Journals (Sweden)

Regina Célia Faria Simão Canesin

2007-08-01

is no research showing results on it. In this way, the aim of this study was to verify the effects of B and Zn applied on leaves on production, SST and ATT of pear fruit and sugar apple. The experiment was conducted on irrigated area in Ilha Solteira - SP, Brazil. A red brown Podzolic and plants of sugar apple and pear, Okussankichi cv. were used. The treatments were: T1. water, T2. boric acid, T3. zinc sulfate, T4. T2 + T3, T5. boric acid + urea + citric acid + EDTA, T6. zinc sulfate + urea + citric acid + EDTA, T7. T5 + T6, T8. boric acid + urea + citric acid + EDTA + sodium molibdate + sulfur + calcium chloride, T9. zinc sulfate + citric acid + EDTA + Fe sulfate + Mn sulfate + Mg sulfate and, T10. T8 +T9. It was used doses of 110 g ha-1 of B and 250 g ha-1 of Zn, in each application. A randomized blocks design was used and to compare the averages the Tukey test was applied. It can be concluded: a the production, SST and ATT of pear fruits and sugar apple fruits were not influenced by B and Zn leaf application, b boric acid plus quelates were efficient to supply B to pear plants but not to sugar apple plants, c Zn sulfate plus quelates caused an increase in Zn leaf content only in pear plants.

Method of decontaminating primary coolant circuits

International Nuclear Information System (INIS)

Ishibashi, Masaru; Sumi, Masao.

1981-01-01

Purpose: To eliminate hard contaminated layers as well as soft contaminated layers without injuring substrate materials, upon decontamination of radiation contaminated portions in equipments and pipeways constituting primary coolant circuits. Constitution: High pressure water from a high pressure pump is jetted out from the nozzle of a spray gun to the radiation contaminated portions in equipments, for example, to the surface of water chamber in a vapor evaporator. High pressure pure water or aqueous boric acid is jetted out from the periphery and boric oxide particles (of about 1 - 100 μ particle size) are jetted out from the center of the nozzle of the spray gun. The particles (blasting material) jetted out together with the high pressure water impinge on the contaminated surfaces to remove the contaminated layers. Upon impingement, the high pressure water acts as the shock absorber for the blasting material and, after the impingement, it flows down to the bottom of the water chamber, and the blasting material is dissolved in the high pressure water. (Horiuchi, T.)

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.

Reference: 382 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available ncentrations in the environment. To investigate how plants survive under conditions of B limitation, we cond...ronidase fusions indicated that NIP5;1 is strongly upregulated in the root elongation zone and the root hair zone under B limitation...e boric acid channel crucial for the B uptake required for plant growth and development under B limitation. ...The Arabidopsis major intrinsic protein NIP5;1 is essential for efficient boron uptake and plant development under boron limitation

Leaching studies of low-level radioactive waste forms

International Nuclear Information System (INIS)

Dayal, R.; Arora, H.; Milian, L.; Clinton, J.

1985-01-01

A research program has been underway at the Brookhaven National Laboratory to investigate the release of radionuclides from low-level waste forms under laboratory conditions. This paper describes the leaching behavior of Cs-137 from two major low-level waste streams, that is, ion exchange bead resin and boric acid concentrate, solidified in Portland cement. The resultant leach data are employed to evaluate and predict the release behavior of Cs-137 from low-level waste forms under field burial conditions

FIRE RESISTANCE OF DOUGLAS FIR [Pseudotsuga menziesii (Mirb. Franco] WOOD TREATED WITH SOME CHEMICALS

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M. Kemal YALINKILIÇ

1998-02-01

Full Text Available Combustible properties of treated douglas wood specimens and fire-retardancy of some preservatives were tested in this study. Crib test of ASTM E 160-150 was followed. Results indicated that, aqueous solutions of boric acid (BA, borax (Bx (Na2BO7 10H2O or BA + Bx mixture (7: 3, w: w had fire retardant efficacy (FRE over untreated wood and reduced the combustibility of vinil monomers (Styrene and methylmetacrylate which were applied as secondary treatment.

Procedure and equipment for continuous manufacture of solutions

International Nuclear Information System (INIS)

Stiefel, M.

1979-01-01

In order to manufacture boric acid solution for reactor commissioning, the heated water is divided into a main and subsidiary flow, and the total amount of the salt is added to the subsidiary flow. Mixing of the main flow with the salt-containing subsidiary flow takes place on a mixing column. Undissolved salt is removed in a hydro-cyclotron. Preheating of the water takes place in a recuperator heat exchanger and a through boiler provides the final temperatures. (HK) [de

Westinghouse Reference Safety Analysis Report, RESAR-414. License application, preliminary safety analysis report (RESAR-414) volume 1

International Nuclear Information System (INIS)

1976-01-01

Westinghouse's standardized four-loop, single unit NSSS for a pressurized water reactor is described including the core, coolant system, ECCS, emergency boration, chemical and volume control, RHR system, boron recycle, fuel handling, spent fuel pool and associated instrumentation and controls. This reactor is applicable to a plant with a core power level of 3800 MW(t) and 1295 MW(e). The reactor is controlled by temperature coefficients of reactivity; control rod motion, and by a soluble neutron absorber-boric acid

Analyses to assess the level of boron dilution in the VVER-1000 primary circuit

International Nuclear Information System (INIS)

Kral, P.; Macek, J.; Krhounkova, J.

2000-12-01

Thermal hydraulic analyses of loss-of-coolant accidents which can result in volumes with a reduced boric acid concentration were performed by using the RELAP5/MOD3.1 code. Small LOCA were calculated (i) without high-pressure pumps (HPP), (ii) with 1/3 HPP, (iii) with 1/3 HPP and cooling via steam dump station to the atmosphere, and (iv) with 1/3 HPP, cooling via steam dump station to the atmosphere, and star of main coolant pump no. 1. (P.A.)

Kombinasi Boraks dan Asam Borat sebagai Bahan Penghambat Api dan Antirayap Pada Kayu Meranti Merah

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Mahdi Santoso

2015-01-01

Full Text Available Kayu mempunyai sifat yang mudah terbakar dan sebagian besar mempunyai keawetan alami yang rendah. Perbaikan kualitas kayu dilakukan untuk mengatasi kelemahan tersebut, salah satunya dengan mengimpregnasikan bahan kimia yang bersifat menghambat api dan beracun terhadap organisme perusak kayu. Tujuan penelitian ini adalah melihat kemampuan boraks:asam borat (1:1 untuk meningkatkan ketahanan kayu meranti merah terhadap api dan rayap kayu kering dan mengetahui proses pengawetan yang efektif. Penelitian ini menggunakan kayu meranti merah (Shorea spp berukuran 6 x 15 x 500 cm. Waktu pengawetan adalah 1, 2, dan 3 jam serta konsentrasi bahan pengawet 7% dalam 5 ulangan. Metode pengawetan menggunakan metode sel kosong dengan tekanan 12 kg/cm2 . Pengujian ketahanan terhadap api mengacu pada ASTM E 69-02 prosedur B, pengujian ketahanan terhadap rayap kayu kering mengacu pada metode rayap makan tanpa pilihan. Parameter yang diamati ialah absorpsi, retensi aktual, intensitas bakar, suhu pembakaran maksimal, lama pembaraan, mortalitas rayap kayu kering, pengurangan berat contoh uji, derajat kerusakan dan kondisi fisik sampel setelah uji bakar. Hasil penelitian menunjukkan bahwa kombinasi boraks:asam borat (1:1 memiliki efektivitas yang tinggi untuk meningkatkan ketahanan kayu meranti merah terhadap api dan rayap kayu kering. Proses pengawetan yang paling efektif adalah lama penekanan 2 jam dengan absorpsi 331 kg/m3 ; retensi aktual 28,8 kg/m3 ; intensitas bakar 10,9%; suhu pembakaran maksimal 140ºC; lama pembaraan 1,03 menit; mortalitas rayap kayu kering 100%; pengurangan berat contoh uji 0,002%; serta derajat kerusakan kategori ringan. Katakunci: penghambat api, anti rayap, boraks, Shorea spp, Cryptotermes cynocephalus   Borax and Boric Acid Combination As Fire Retardant and Anti-termite Agents on Red Meranti Wood Abstract Woods have properties which are easy to be ignited by fire and most of them have a low natural durability. Therefore, it is required to

Method for testing the radioactivity of objects containing metal or concrete

Energy Technology Data Exchange (ETDEWEB)

Hanulik, J [Recytec SA, (Switzerland)

1991-12-31

Radioactively contaminated objects are placed into a borofluoric acid bath following a rough spot test and are precipitated in a measurable geometry on the cathode plates in the course of an electrolytic process, for example. In the course of the subsequent testing, the metals lying below a pre-determined maximum value of radioactive emissions are separated and supplied to the waste reclamation. The materials lying above this threshold value during the spot testing are first decontaminated and then placed in the acid bath. The borofluoric acid is not used up in this process and remains in the system. It is possible to use already radioactively contaminated boric acid from pressurized water reactors, to which it is merely required to add fluoric acid and to distill, for generating borofluoric acid. The method in accordance with the invention reduces the radioactive waste and reduces the testing and administrative effort required for the release of the non-radioactive materials. (author) 1 tab., 4 figs.

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)

Radiochemical neutron activation analysis of gold in geochemical samples

International Nuclear Information System (INIS)

Zilliacus, R.

1983-01-01

A fast method for the radiochemical neutron activation analysis of gold in geochemical samples is described. The method is intended for samples having background concentrations of gold. The method is based on the dissolution of samples with hydrofluoric acid and aqua regia followed by the dissolution of the fluorides with boric acid and hydrochloric acid. Gold is then adsorbed on activated carbon by filtrating the solution through a thin carbon layer. The activity measurements are carried out using a Ge(Li)-detector and a multichannel analyzer. The chemical yields of the separation determined by reirradiation vary between 60 and 90%. The detection limit of the method is 0.2 ng/g gold in rock samples. USGS standard rocks and exploration reference materials are analyzed and the results are presented and compared with literature data. (author)

Analytical methods for the determination of boron in reactor materials programme

International Nuclear Information System (INIS)

Chitre, R.S.; Joshi, V.R.; Iyer, C.S.P.

1983-01-01

Spectrophotometric methods of determination of boron based on the complexation reaction between boric acid and protonated curcumin are briefly reviewed. Direct determination of boron in heavy water, plant leaves, copper and its alloys, and aluminium and its alloys using a modified method of Hayes and Metcalfe is described. A method for determination of boron, when its content is very low as in case of uranium metal, diuranate, uranium oxide and thorium nitrate, is also described. In this method, boron is first separated as methyl borate by distillation of the sample with methanol in acid media. The distilled ester is absorbed by hydroxide solution and boron is analysed after removal of methanol. The precision obtained is indicated. (M.G.B.)

On the mechanism of boron transfer through the cation-exchange membrane MK-40

International Nuclear Information System (INIS)

Pilipenko, A.T.; Varvaruk, L.A.; Grebenyuk, V.D.; Trachevskij, V.V.

1985-01-01

Proceses of boron electromigration in solutions with different pH values are investigated. It is shown, that boron transfer through ion-exchange membranes is determined by pH of solution. Phenomenon of boron transfer (existing in the solution in the form of boric acid) through cation-exchange membrane MK-40 has been detected and described for the first time. The process of boron (3) complexing with sulfate groups of the membrane by means of competing reversible substitution of hydroxoligands is the basis of the phenomenon

A Preliminary Study on the Containment Integrity following BIT Removal for Kori NPP Unit 3,4

Energy Technology Data Exchange (ETDEWEB)

Song, Dong Soo; Byun, Choong Sup [KEPRI, Nuclear Power Generation Laboratory, Daejeon (Korea, Republic of); Jo, Jong Young [ENERGEO Inc., Sungnam (Korea, Republic of)

2008-05-15

The Boron Injection Tank (BIT) is to provide high concentrated boric acid to the reactor in order to mitigate the consequences of postulated Main Steam Line Break accidents (MSLB). Although BIT plays an important role in mitigating the accident, high concentration of 20,000ppm causes valve leakage, pipe clog, precipitation and continuous heat tracing have to be provided. This paper is for the feasibility study of containment integrity using CONTEMPT code for BIT removal of Kori Nuclear Power Plant (NPP) Unit 3, 4.

A Preliminary Study on the Containment Integrity following BIT Removal for Kori NPP Unit 3,4

International Nuclear Information System (INIS)

Song, Dong Soo; Byun, Choong Sup; Jo, Jong Young

2008-01-01

The Boron Injection Tank (BIT) is to provide high concentrated boric acid to the reactor in order to mitigate the consequences of postulated Main Steam Line Break accidents (MSLB). Although BIT plays an important role in mitigating the accident, high concentration of 20,000ppm causes valve leakage, pipe clog, precipitation and continuous heat tracing have to be provided. This paper is for the feasibility study of containment integrity using CONTEMPT code for BIT removal of Kori Nuclear Power Plant (NPP) Unit 3, 4

Reactions of 1,3-dioxacycloalkanes and their 2-arsena, 2-bora, 2-germa, 2-sila, and 2-thia analogs with nitriles

International Nuclear Information System (INIS)

Kuznetsov, V.V.

2005-01-01

New reactions of five-, six-, and seven-membered 1,3-dioxacycloalkanes and their 2-arsena, 2-bora, 2-germa, 2-sila, and 2-thia analogs with nitriles giving rise to 1,3-oxazacycloalkanes and then to amino alcohols are surveyed. The reactions under consideration, including the reactions of boronic and boric acid esters with nitriles, supplement the known chemical transformations of 1,3-dioxacycloalkanes and their 2-hetero atomic analogs and provide a wide scope for the synthesis of diverse functional derivatives on their basis [ru

Nanomaterials in Lubricants: An Industrial Perspective on Current Research

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Boris Zhmud

2013-11-01

Full Text Available This paper presents an overview on the use of various classes of nanomaterials in lubricant formulations. The following classes of nanomaterials are considered: fullerenes, nanodiamonds, ultradispersed boric acid and polytetrafluoroethylene (PTFE. Current advances in using nanomaterials in engine oils, industrial lubricants and greases are discussed. Results of numerous studies combined with formulation experience of the authors strongly suggest that nanomaterials do indeed have potential for enhancing certain lubricant properties, yet there is a long way to go before balanced formulations are developed.

Study of two-zone reactor system using a pulsed neutron technique

Energy Technology Data Exchange (ETDEWEB)

Shishin, B P; Platovskikh, Yu A; Didejkin, T S

1977-05-01

Theoretical and experimental investigations of a neutron flux time dependence after a sport fast neutron pulse in a reactor core - neutron reflector multiplying system have been conducted. A correlation between eigenvalues governing neutron flux decrease at t..-->..infinity for the two-zone system and eigenvalues for each zone has been established in terms of the one-group diffusion approximation. Experiments have been performed in an experimental subcritical assembly comprising a cylindrical uranium core surrounded by a radial water reflector with different boric acid concentrations.

Evaluation of spiral wound reverse osmosis for four radioactive waste processing applications

International Nuclear Information System (INIS)

Sen Gupta, S.K.

1997-01-01

A pilot-scale spiral wound reverse osmosis rig was used to treat four significantly different radioactive waste streams, three of which were generated at the Chalk River Laboratories at AECL. These streams included: 1. A chemical decontamination (CD/DC) waste stream which is routinely treated by the plant-scale membrane system at CRL; 2. Reactor waste which is a dilute radioactive waste stream (containing primarily tritium and organic acids), and it an effluent from the operating reactors at AECL; 3. An ion exchange regenerant waste stream which contains a mixture of stream (1) (CD/DC), blended with secondary waste from ion exchange regeneration; 4. Boric acid simulated waste which is a by-product waste of the PWR reactors. This was the only stream treated that was not generated as a waste liquid at AECL. For the first three streams specified above, reverse osmosis was used to remove chemical and radiochemical impurities from the water with efficiencies usually exceeding 99%. In these three cases the 'permeate' or clean water was the product of the process. In the case of stream 4, reverse osmosis was used in a recovery application for the purpose of recycling boric acid back to the reactor, with the concentrate being the 'product'. Reverse osmosis technology was successfully demonstrated for the treatment of all four streams. Prefiltration and oxidation (with photocatalytic continuous oxidation technology) were evaluated as pretreatment alternatives for streams 1, 2, and 3. The results indicated that the effective crossflow velocity through and membrane vessel was more important in determining the extent of membrane fouling than the specific pretreatment strategy employed. (author)

FONTES E DOSES DE BORO NA QUALIDADE DE SEMENTES DE FEIJÃO-COMUM E MAMONA SOB CONSÓRCIO

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MATEUS LELES LIMA

2013-01-01

Full Text Available Elevated productivity of castor and common bean in intercropping is obtained with the use of quality seeds, where boron plays an important role in plant nutrition. The objective of the this study was to evaluate the physiological quality of seeds of the common bean and castor grown in intercropping syste ms, subject to different sources and levels of boron. A completely randomized design was used in a 2 x 5 + 2 facto- rial scheme with four replications. Treatments cons isted of two sources of boron (borax = 11% B and bo ric acid = 17% B, combined with five boron doses (0.0, 0.5, 1.0, 2.0 and 4.0 kg ha -1 of B in the soil in intercropping of the common bean with castor, plus additional treatm ents of common bean and castor in monoculture. It w as concluded that boric acid permitted for acquisition of common bean seeds with the highest germination per- centage when intercropped with castor. Use of the d ose of 1.5 kg ha -1 of boron in the soil resulted in acquisition of seeds of the common bean with vigor of 79% when intercropped with castor, regardless of the boron s ource. Employing 2.3 kg ha -1 of boron, with the source being either boric acid or borax, influenced the vigor of castor seeds produced when intercropped with the common be an. The addition of boron by soil fertilization, in de- pendent of the source used, did not affect the phys iological quality of common bean seeds or castor se eds pro- duced in monoculture.

The iron and cerium oxide influence on the electric conductivity and the corrosion resistance of anodized aluminium

International Nuclear Information System (INIS)

Souza, Kellie Provazi de

2006-01-01

The influence of different treatments on the aluminum system covered with aluminum oxide is investigated. The aluminum anodization in sulphuric media and in mixed sulphuric and phosphoric media was used to alter the corrosion resistance, thickness, coverage degree and microhardness of the anodic oxide. Iron electrodeposition inside the anodic oxide was used to change its electric conductivity and corrosion resistance. Direct and pulsed current were used for iron electrodeposition and the Fe(SO 4 ) 2 (NH 4 ) 2 .6H 2 O electrolyte composition was changed with the addition of boric and ascorbic acids. To the sealing treatment the CeCl 3 composition was varied. The energy dispersive x-ray (EDS), the x-ray fluorescence spectroscopy (FRX) and the morphologic analysis by scanning electronic microscopy (SEM) allowed to verify that, the pulsed current increase the iron content inside the anodic layer and that the use of the additives inhibits the iron oxidation. The chronopotentiometric curves obtained during iron electrodeposition indicated that the boric and ascorbic acids mixture increased the electrodeposition process efficiency. The electrochemical impedance spectroscopy (EIE), the Vickers (Hv) microhardness measurements and morphologic analysis evidenced that the sealing treatment improves the corrosion resistance of the anodic film modified with iron. The electrical impedance (EI) technique allowed to prove the electric conductivity increase of the anodized aluminum with iron electrodeposited even after the cerium low concentration treatment. Iron nanowires were prepared by using the anodic oxide pores as template. (author)

Establishment of the operating procedure to prevent boron precipitation during Post-LOCA long term cooling for Korean Westinghouse 3-loop NPPs

International Nuclear Information System (INIS)

Choi, Han Rim; Kwon, Tae Soon; Ban, Chang Hwan; Jeong, Jae Hoon; Lee, Young Jin.

1996-11-01

During post-LOCA LTC the increase of the excess reactivity for the extended fuel cycle should require increasing the RWST boron concentration in order to ensure core subcritical state. To quantify the concentration increment, the calculation methods was developed for the post-LOCA RCS/Sump mixed mean boron concentration, which applied for Kori 3 and 4 and Ulchin 1 and 2 of the Westinghouse 3-loop nuclear power plants in Korean. From the calculation results, the minimum boric acid concentrations increased of the RWST and accumulator were determined consideration of the convenient operation for operator on reloading. Boric acid concentrations of the RWST and the accumulators for Westinghouse 3-loop type plants were increased to meet the post-LOCA shutdown requirement for the long life cycles from 12 months to 18 months. To maintain LTC capability following a LOCA, the switchover time is examined using boron code of prevent the boron precipitation in the reactor core with the increased boron concentrations. The analysis results showed that hot leg recirculation switchover times were shortened to 7.5 hours from 24 hours after the initiation of LOCA for Kori 3 and 4 and 8 hours from 18 hours for Ulchin 1 and 2, respectively. The flow path in the mode J for Kori 3 and 4 was recommended to realign to the simultaneous recirculation of both hot and cold legs from the cold leg recirculation, as done by Ulchin 1 and 2. (author). 2 tabs., 12 figs., 13 refs

Management of low level waste generated from ISER

International Nuclear Information System (INIS)

Mizushina, Tomoyuki

1987-01-01

Low level wastes are generated during nuclear power plant operation. In the case of ISER, low level wastes from the reactor are basically the same as of existing light water reactors. Various low level wastes, including solid, liquid and gaseous, are listed and discussed. In normal operation, high-activity wastes are not subjected to any treatment. For contaminated equipment or reactor parts, it may be desirable to transfer most of the activity to liquid phase through an appropriate decontamination procedure. Highly active solid wastes are usually fixed in a solid form through incorporation into either concrete or asphalt as containment material. Decantation and filtration treatments are usually sufficient before dilution and release of liquid wastes into the environment. Except for ordinary gas filtration, there in normally no other treatment. Under certain circumstances, however, it may be important to apply the decay storage before release to the atmosphere. In accidental circumstances, specific filtration is recommended or even sometimes needed. There are some alternatives for storage and-or disposal of low level wastes. In many cases, shallow land burial is chosen as a realistic method for storage and-or disposal of solid waste. In chosing a disposal method, the radiation dose rate from solid wastes or the specific activity should be taken into account. Boric acid is a retarder for cement setting. This effect of boric acid is inhibited by adding a complexing agent before mixing the waste with cement. (Nogami, K.)

Ultrasonic Phased Array Assessment of the Interference Fit and Leak Path of the North Anna Unit 2 Control Rod Drive Mechanism Nozzle 63 with Destructive Validation

Energy Technology Data Exchange (ETDEWEB)

Crawford, Susan L.; Cinson, Anthony D.; MacFarlan, Paul J.; Hanson, Brady D.; Mathews, Royce

2012-08-01

The objective of this investigation was to evaluate the efficacy of ultrasonic testing (UT) for primary water leak path assessments of reactor pressure vessel (RPV) upper head penetrations. Operating reactors have experienced leakage when stress corrosion cracking of nickel-based alloy penetrations allowed primary water into the annulus of the interference fit between the penetration and the low-alloy steel RPV head. In this investigation, UT leak path data were acquired for an Alloy 600 control rod drive mechanism nozzle penetration, referred to as Nozzle 63, which was removed from the North Anna Unit 2 reactor when the RPV head was replaced in 2002. In-service inspection prior to the head replacement indicated that Nozzle 63 had a probable leakage path through the interference fit region. Nozzle 63 was examined using a phased-array UT probe with a 5.0-MHz, eight-element annular array. Immersion data were acquired from the nozzle inner diameter surface. The UT data were interpreted by comparing to responses measured on a mockup penetration with known features. Following acquisition of the UT data, Nozzle 63 was destructively examined to determine if the features identified in the UT examination, including leakage paths and crystalline boric acid deposits, could be visually confirmed. Additional measurements of boric acid deposit thickness and low-alloy steel wastage were made to assess how these factors affect the UT response. The implications of these findings for interpreting UT leak path data are described.

The determination of magnesium in simulated PWR coolant by graphite furnace atomic absorption spectrometry

International Nuclear Information System (INIS)

Gatford, C.; Torrance, K.

1988-06-01

The determination of magnesium in simulated PWR coolant has been investigated by graphite furnace atomic absorption spectrometry with atomization from a L'vov platform. The presence of boric acid in the coolant suppresses the magnesium absorption to such an extent that removal of the boron is necessary and three variations of a methyl borate volatilization technique for the in situ removal of boron from the sample platform were investigated. This work has shown that dilution of the sample with an equal volume of acidified methanol and volatilization of the methyl borate was adequate for the determination of magnesium in coolant samples containing up to 2000 mg 1 -1 of boron. In simulated coolant samples containing 25 and 4 μg 1 -1 of magnesium, positive biases of about 2 and 0.5 μg 1 -1 were measured and these errors were considered to be due to contamination. The limit of detection in the presence of 100 and 2000 mg 1 -1 boron were 0.14 and 0.93 μg 1 -1 respectively. These performance characteristics suggest the method is completely acceptable for monitoring the chemical purity of PWR coolant and associated waters containing boric acid. If, however, more precise analyses were to be required for research purposes then any significant improvement in the above figures would require increased purity of reagents, clean-room conditions to reduce contamination and a more versatile atomic absorption spectrophotometer. (author)

Cement matrix for immobilisation of spent anionic resins in borate form arising from nuclear power plants

International Nuclear Information System (INIS)

Sathi Sasidharan, N.; Deshingkar, D.S.; Wattal, P.K.

2005-11-01

In water cooled reactors boron is added as boric acid to control nuclear reactor power levels. The boric acid concentration in coolant/moderator water, is controlled by using strongly basic anionic resins in borate (H 2 BO 3 - ) form. The spent anionic resins in borate form contain 131 Iodine, 99 Technitium and 137 Cesium activities. Direct immobilisation of anionic resins in borate form in Ordinary Portland Cement (OPC) and Slag Cement was investigated using vermiculite, bentonite, calcium oxide and silica as admixtures. The cumulative fraction of 137 Cesium leached and 137 Cesium leach rate for slag cement matrix were 0.029 and 0.00064 g.cm 2 .d -1 respectively for 95 days of leaching. The volume reduction factor achieved by direct immobilisation of anionic resins in borate form was 0.48. Immobilisation of pyrolysis residues from these resins in OPC matrix was also studied. Leaching of matrix blocks was carried out for 180 days in DM water to optimise the matrix formulation. The cumulative fraction of 137 Cesium leached and 137 Cesium leach rate were 0.076 and 0.00054 respectively for 180 days leaching. The volume reduction factor achieved by immobilisation of pyrolysis residues was 2.4. OPC is non compatible to cationic resins loaded with alkali in absence of specific admixtures. Hence cationic resins loaded with alkali and anionic resins in borate form can not be immobilised together. (author)

The iron and cerium oxide influence on the electric conductivity and the corrosion resistance of anodized aluminium; A influencia do ferro e do oxido de cerio sobre a condutividade eletrica e a resistencia a corrosao do aluminio anodizado

Energy Technology Data Exchange (ETDEWEB)

Souza, Kellie Provazi de

2006-07-01

The influence of different treatments on the aluminum system covered with aluminum oxide is investigated. The aluminum anodization in sulphuric media and in mixed sulphuric and phosphoric media was used to alter the corrosion resistance, thickness, coverage degree and microhardness of the anodic oxide. Iron electrodeposition inside the anodic oxide was used to change its electric conductivity and corrosion resistance. Direct and pulsed current were used for iron electrodeposition and the Fe(SO{sub 4}){sub 2}(NH{sub 4}){sub 2}.6H{sub 2}O electrolyte composition was changed with the addition of boric and ascorbic acids. To the sealing treatment the CeCl{sub 3} composition was varied. The energy dispersive x-ray (EDS), the x-ray fluorescence spectroscopy (FRX) and the morphologic analysis by scanning electronic microscopy (SEM) allowed to verify that, the pulsed current increase the iron content inside the anodic layer and that the use of the additives inhibits the iron oxidation. The chronopotentiometric curves obtained during iron electrodeposition indicated that the boric and ascorbic acids mixture increased the electrodeposition process efficiency. The electrochemical impedance spectroscopy (EIE), the Vickers (Hv) microhardness measurements and morphologic analysis evidenced that the sealing treatment improves the corrosion resistance of the anodic film modified with iron. The electrical impedance (EI) technique allowed to prove the electric conductivity increase of the anodized aluminum with iron electrodeposited even after the cerium low concentration treatment. Iron nanowires were prepared by using the anodic oxide pores as template. (author)

COMBUSTION PROPERTIES OF EUCALYPTUS WOOD

Directory of Open Access Journals (Sweden)

Yalçın ÖRS

1999-03-01

Full Text Available In this study, the combustion properties of some impregnation materials (abiotic and biotic factors used for eucalyptus wood in interior or exterior environments were investigated. The experimental samples were prepared from Eucalyptus wood based on ASTM-D-1413-76 Tanalith-CBC, boric acid, borax, vacsol-WR, immersol-WR, polyethylen glycole-400 and ammonium sulphate were used as an impregnation material. The results indicated that, vacuum treatment on Eucalyptus gave the lowest retention value of salts. Compounds containing boron+salt increased fire resistance however water repellents decreased the wood flammability.

Chemistry aspects of the Falcon programme

International Nuclear Information System (INIS)

Beard, A.M.; Bennett, P.J.; Benson, C.G.; Sabathier, F.

1990-12-01

Experiments have been conducted in the Falcon facility to study the interaction of fission product vapours released from simulant and trace-irradiated fuel samples with bulk-materials aerosol such as control rod alloy and boric acid. These experiments were designed in collaboration with computer code specialists to represent, as closely as possible, the conditions pertaining within a severe reactor accident. Small segments of fuel were heated to ∼2000 K and the resulting vapour-aerosol release was studied along a pathway simulating the upper plenum, hot-leg structures and containment. (author)

Separation of boron isotopes by ion exchange chromatography: studies on regeneration of strong base anion exchange resins

International Nuclear Information System (INIS)

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

1994-01-01

The optimum conditions for the regeneration of strong base anion exchange resins of type-I and type-II were determined for cost-effective separation of isotopes of boron by ion exchange chromatography where the hydroxyl form of an anion exchange resin is equilibrated with boric acid solution containing mannitol as a complexing reagent. The possibility of using unspent alkali content of the effluent was also exploited. Removal of carbonate impurity from Rayon grade caustic lye (used as regenerant after dilution) and recycling of Ba(OH) 2 was studied to avoid waste disposal problems. (author)

Recent bibliography on analytical and sampling problems of a PWR primary coolant Suppl. 3

International Nuclear Information System (INIS)

Illy, H.

1985-03-01

The present supplement to the bibliography on analytical and sampling problems of PWR primary coolant covers the literature published in 1984 and includes some references overlooked in the previous volumes dealing with the publications of the last 10 years. References are devided into topics characterized by the following headlines: boric acid; chloride; chlorine; carbon dioxide; general; gas analysis; hydrogen isotopes; iodine; iodide; nitrogen; noble gases and radium; ammonia; ammonium; oxygen; other elements; radiation monitoring; reactor safety; sampling; water chemistry. Under a given subject bibliographical information is listed in alphabetical order of the authors. (V.N.)

Designing your boron-charging system

International Nuclear Information System (INIS)

Miller, J.

1979-01-01

High-pressure positive-displacement pumps used in the boron-charging setups of pressurized-water (PWR) nuclear plants because of their inherently high efficiencies over a wide range of pressures and speeds are described. Hydrogen-saturated water containing 4-12% boric acid is fed to the pump from a volume-control tank under a gas blanket. Complicated piping and the pulsation difficulties associated with reciprocating pumps make hydrogen-saturated boron-charging systems a challenge to the designer. The article describes the unusual hydraulics of the systems to help assure a trouble-free design

Separation of boron isotopes using NMG type anion exchange resin

International Nuclear Information System (INIS)

Itagaki, Takaharu; Kosuge, Masao; Fukuda, Junji; Fujii, Yasuhiko.

1992-01-01

Ion exchange separation of boron isotopes (B-10 and B-11) has been studied by using a special boron selective ion exchange resin; NMG (n-methyl glucamine)-type anion exchange resin. The resin has shown a large isotope separation coefficient of 1.02 at the experimental conditions of temperature, 80degC, and boric acid concentration, 0.2 M (mole/dm 3 ). Enriched B-10 (92%) was obtained after the migration of 1149 m by a recyclic operation of ion exchange columns in a merry-go-round method. (author)

Determination of boron in waters by using methyl borate generation and flame atomic-emission spectrometry

International Nuclear Information System (INIS)

Castillo, J.R.; Mir, J.M.; Martinez, C.; Bendicho, C.

1985-01-01

An improved method is proposed for the determination of boron in waters. The esterification reaction between boric acid and methanol in a concentrated sulphuric acid medium and the vaporisation of the methyl borate formed (boiling-point, 68 C) are used in the determination by boron by measuring the emission of the BO 2 radical at 548 nm. This reaction is carried out in a simple and inexpensive generator, designed for this purpose, and the heat developed in it causes the rapid volatilisation of the methyl borate. Thus no collection systems or carrier gas are required. The proposed method gives an improved detection limit and it can be applied to the determination of boron in water samples. It is both rapid and highly selective. (author)

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

Indian Academy of Sciences (India)

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

Canada - Atomic Energy Control Board, Canada. Summary of a common cause failure event which occurred in a Canadian utility. 'Failure to Verify Poison Isotopic'

International Nuclear Information System (INIS)

1996-01-01

Operating Policies and Principles (OP and Ps) are referenced in the reactor operating license. They contain not only general safety principles, but also define safety parameters and their numerical values for the operation of the nuclear power plant. The event described highlights the difficulties to implement the OP and Ps into detailed purchase orders. In Candu reactors gadolinium nitrate and boric oxide are used as neutron absorbers in the moderator. The concentration of neutron absorbers in the moderator is safety significant because a small change in concentration in coincidence with other failures (e.g. LOCA) can result in a sudden increase of power. To ensure that new shipments of gadolinium nitrate or boric acid meet the required specifications, these must undergo quarantine so that samples could be taken and forwarded for analysis. The chemistry unit of the NPP issued this requirements in a 'note to file'. In the event, two separated purchase orders, one for gadolinium nitrate and one for boric oxide, were placed. The purchase orders did not stipulate the requirements to quarantine, inform the chemistry unit or to analyse samples. They only stated that correct isotopic and chemical purity were required. The gadolinium nitrate as well as the boron oxide were both not quarantined and even the purity was not verified. The chemistry unit felt that a 'note to file' memo was sufficient to ensure that the OP and Ps are met taking into account the low shipment rate and sufficient experiences before. The analysis of the event revealed several causal factors. Four main factors were pointed out: - Work practices, - Resource Management, - Written communication, - Managerial methods. The actions taken after the event focused on the identified deficiencies

Synthesis of magnetic nanoparticles as a draw solute in forward osmosis membrane process for the treatment of radioactive liquid waste

International Nuclear Information System (INIS)

Yang, Heeman; Lee, Kune Woo; Moon, Jei Kwon

2013-01-01

These wastes contain about 0.3 ∼ 0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40 ∼ 90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. As an emerging technology forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination because FO operates at low or no hydraulic pressures. FO is a membrane process in which water flows across a semi-permeable membrane from a feed solution of lower osmotic pressure to a draw solution of higher osmotic pressure. However, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe 3 O 4 nanoparticles can be separated from water by an external magnet field easily. If Fe 3 O 4 nanoparticles are coated with highly soluble organic substances, thus they can be used as a draw solute by concurrently generating high osmotic pressure and easy separation. The carboxylated polyglycerol coated Fe 3 O 4 nanoparticles have been successfully synthesized. The nanoparticles were about 50 nm in diameter and showed the good colloidal stability in aqueous solution. The osmolality and osmotic pressure were enough high to be used as a draw solute in FO. For the future work, we will investigate the performance of our magnetic draw solute in FO to remove boron in the simulated liquid waste

The effect of the boron source composition ratio on the adsorption performance of hexagonal boron nitride without a template

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ning, E-mail: zhangning5832@163.com; Zhang, Tong; Kan, Hongmin; Wang, Xiaoyang; Long, Haibo; Cui, Xingyu

2015-08-01

An inexpensive boric acid (H{sub 3}BO{sub 3}) and borax (Na{sub 2}B{sub 4}O{sub 7}·10H{sub 2}O) mix was used as a source of boron with different composition ratios, and urea was used as a nitrogen source, in flowing ammonia atmosphere, for the preparation of hexagonal boron nitride (h-BN) with different micro-morphologies. Under a certain synthesis process, the effects of the molar ratio of borax and boric acid (or simply the boron source composition ratio for short) on the phase composition of the sample were studied; the work also explored the effect of boron source composition ratio on the micro-morphology, adsorption desorption isotherm and specific surface area of the h-BN powder. The main purpose of this work was to determine the optimum composition ratio of preparing spherical mesoporous h-BN and ensure that the micro-mechanism underpinning the formation of spherical mesoporous h-BN was understood. The results showed that at the optimum boron source composition ratio of 1:1, globular mesoporous spheres with a diameter of approximately 600–800 nm could be obtained with the highest pore volume and specific surface area (230.2 m{sup 2}/g). - Graphical abstract: Display Omitted - Highlights: • Spherical h-BN was synthesized by controlling the boron source composition ratio. • Without extra spherical template, solid Na{sub 2}O was equal to a spherical template. • At boron source composition ratio of 1:1, h-BN had best adsorption performance.

Non-albicans Candida Vulvovaginitis: Treatment Experience at a Tertiary Care Vaginitis Center.

Science.gov (United States)

Powell, Anna M; Gracely, Edward; Nyirjesy, Paul

2016-01-01

The aims of this study are to analyze a cohort of women with vulvovaginal symptoms and positive cultures for non-albicans Candida (NAC) to determine whether yeast was responsible for their symptoms and to evaluate the mycological effectiveness of various regimens. This observational study was performed from retrospective chart review of patients with positive NAC cultures between April 1, 2008, and January 31, 2011, at a tertiary care vaginitis center. Patient intake demographics were entered into a database. Follow-up visits were analyzed for data about patient treatments and outcomes. Patients were considered a clinical cure if their symptoms were significantly improved and mycologic cure (MC) if later yeast cultures were negative. If clinical symptoms improved at the same time as MC, the isolate was considered the proximate cause for the symptoms. One hundred eight patients meeting entry criteria were analyzed. Boric acid was effective at obtaining MC in 32 (78%) of 41 patients with C. glabrata, 3 of 3 patients with C. tropicalis, and 3 of 3 patients with C. lusitaniae. Fluconazole was effective as initial treatment for 3 (60%) of 5 patients with C. glabrata and 13 (81%) of 16 patients with C. parapsilosis. In 52.7% of C. glabrata, 66.7% of C. parapsilosis, and 57.1% of C. tropicalis cases, effective antifungal therapy led to symptom improvement. In a tertiary care vaginitis center, NAC, when isolated on culture, caused clinically significant infections in approximately half of symptomatic patients. A majority of infections can be effectively treated with boric acid or fluconazole regardless of the non-albicans Candida species.

Impact of urine preservation methods and duration of storage on measured levels of environmental contaminants.

Science.gov (United States)

Hoppin, Jane A; Ulmer, Ross; Calafat, Antonia M; Barr, Dana B; Baker, Susan V; Meltzer, Helle M; Rønningen, Kjersti S

2006-01-01

Collection of urine samples in human studies involves choices regarding shipping, sample preservation, and storage that may ultimately influence future analysis. As more studies collect and archive urine samples to evaluate environmental exposures in the future, we were interested in assessing the impact of urine preservative, storage temperature, and time since collection on nonpersistent contaminants in urine samples. In spiked urine samples stored in three types of urine vacutainers (no preservative, boric acid, and chlorhexidine), we measured five groups of contaminants to assess the levels of these analytes at five time points (0, 24, 48, and 72 h, and 1 week) and at two temperatures (room temperature and 4 degrees C). The target chemicals were bisphenol A (BPA), metabolites of organophosphate (OP), carbamate, and pyrethroid insecticides, chlorinated phenols, and phthalate monoesters, and were measured using five different mass spectrometry-based methods. Three samples were analyzed at each time point, with the exception of BPA. Repeated measures analysis of variance was used to evaluate effects of storage time, temperature, and preservative. Stability was summarized with percent change in mean concentration from time 0. In general, most analytes were stable under all conditions with changes in mean concentration over time, temperature, and preservative being generally less than 20%, with the exception of the OP metabolites in the presence of boric acid. The effect of storage temperature was less important than time since collection. The precision of the laboratory measurements was high allowing us to observe small differences, which may not be important when categorizing individuals into broader exposure groups.

Optimizing the use of gadolinium as burnable poison in nuclear fuel: towards a boron free PWR

International Nuclear Information System (INIS)

Pieck, D.

2013-01-01

Reactivity excess in Nuclear Power Plants is controlled by reactor's active systems: boric acid dilution and control rods. Alternatively, negative reactivity insertion can be made in a passive way using burnable poisons, i.e. neutron absorbers, this is the case of gadolinium (Gd). In the industrial framework of U 235 enrichment increase and boric acid restraint, the goal of this thesis is to optimize the distribution of gadolinium in UO 2 ceramics to obtain a high-performance provision of negative reactivity in Pressurized Water Reactors. In this sense, the work is focus on new gadolinium-rich materials. Thus, U-Gd-O phase diagram was explored in the field of high Gd contents. Two cubic phases were found and characterized: the C1 and C2 phases. With the aim of an industrial application, C1 phase was selected as candidate for Gd addition into UO 2 pellets. The optimal distribution of C1 phase within a nuclear fuel assembly was studied using APOLLO 2.8 neutron transport code. Parametric calculations were performed. These neutronic studies have ends in a successful 'concept of poisoned pellet'. Finally, some prototype pellets following this concept were made in laboratory to proof it feasibility. All the obtained results shows that the proposed concept of a neutro-phage C1-phase coating on UO 2 pellets is a convenient way to reduce reactivity excess within the framework of long irradiation cycles. This concept could be potentially applied in industrial scale. Consequently a patent application process was initiated.(author) [fr

Application of a unique test design to determine the chronic toxicity of boron to the aquatic worm Lumbriculus variegatus and fatmucket mussel Lampsilis siliquoidea.

Science.gov (United States)

Hall, Scott; Lockwood, Rick; Harrass, Michael C

2014-01-01

The chronic (21- and 28-day) toxicity of boron was determined for two freshwater benthic macroinvertebrates: the fatmucket mussel Lampsilis siliquoidea and the aquatic worm Lumbriculus variegatus. The rapid depletion of boric acid from spiked sediments in tests using flow-through overlying waters was addressed by constant addition of boric acid to overlying water at concentrations matching those of the targeted porewater exposures. This proved highly successful in maintaining constant whole-sediment and sediment porewater boron concentrations. Boron sublethal 25 % inhibition concentration values based on porewater concentrations were 25.9 mg B/L (L. variegatus) and 38.5 mg B/L (L. siliquoidea), indicating similar test organism sensitivity. Expressed as dry whole-sediment values, the respective L. variegatus and L. siliquoidea sublethal (growth) IC25 values for whole-sediment exposures were 235.5 mg B/kg sediment dry weight (dw) and 310.6 mg B/kg dw. The worm lethality-based end points indicated greater sensitivity than the sublethal end points, bringing into question the validity of a "lethality" end point for L. variegatus given its fragmentation mode of reproduction. For comparison, water-only mussel exposures were tested resulting in an IC25 value of 34.6 mg B/L, which was within 20 % of the porewater value. This suggests that the primary route of boron exposure was through the aqueous phase. The results of this study indicated that for test materials that are readily water soluble, standard sediment test designs may be unsuitable, but water-only exposures can provide toxicological data representative of sediment tests.

Safety systems I/C reliability analysis of the Kozloduy NPP units 5 and 6; Analiz nadezhnosti KIP i sistem bezopasnosti pyatogo i shestogo bloka AEhS `Kozloduy`

Energy Technology Data Exchange (ETDEWEB)

Marinova, B [Risk Engineering Ltd., Sofia (Bulgaria)

1996-12-31

The purpose of the analysis is to assess the safety systems I/C equipment reliability of the Kozloduy-5 and the Kozloduy-6 reactors. The assessment of quantitative and qualitative effect of control systems unavailability on the safety systems unavailability is performed. The analysis is limited to the following systems: sprinkler management, low pressure emergency spray, emergency injection of boric acid, hydro accumulators, pressure compensator and compressed air. The code for probabilistic safety assessment PSAPACK has been used in analysis. Fault trees for all analysed safety systems have been constructed. Results indicates a high reliability of the safety systems management.

Method to improve lubricity of low-sulfur diesel and gasoline fuels

Science.gov (United States)

Erdemir, Ali

2004-08-31

A method for providing lubricity in fuels and lubricants includes adding a boron compound to a fuel or lubricant to provide a boron-containing fuel or lubricant. The fuel or lubricant may contain a boron compound at a concentration between about 30 ppm and about 3,000 ppm and a sulfur concentration of less than about 500 ppm. A method of powering an engine to minimize wear, by burning a fuel containing boron compounds. The boron compounds include compound that provide boric acid and/or BO.sub.3 ions or monomers to the fuel or lubricant.

Solidification of radioactive waste in a cement/lime mixture

International Nuclear Information System (INIS)

Zhou, H.; Colombo, P.

1984-01-01

The suitability of a cement/lime mixture for use as a solidification agent for different types of wastes was investigated. This work includes studies directed towards determining the wasted/binder compositional field over which successful solidification occurs with various wastes and the measurement of some of the waste from properties relevant to evaluating the potential for the release of radionuclides to the environment. In this study, four types of low-level radioactive wastes were simulated for incorporation into a cement/lime mixture. These were boric acid waste, sodium sulfate wastes, aion exchange resins and incinerator ash. 7 references, 3 figures, 2 tables

Basic information about development and construction of a PWR

International Nuclear Information System (INIS)

Meyer, P.J.

1977-01-01

1.0) Plant layout of a PWR; 2.0) principle design of a PWR and the reactor coolant system; 3.0) reactor auxiliary and ancillary systems; 3.1) volume control system; 3.2) boric acid control and chemical feeding system; 3.3) coolant purification and degassing system; 3.4) coolant storage and treatment system; 3.5) nuclear component cooling system; 3.6) liquid waste processing system; 3.7) gaseous waste processing system; 4.0) residual heat removal system; 5.0) emergency feedwater system; 6.0) containment design; 7.0) fuel handling, storage and transport system in a PWR. (orig.) [de

Corrosion rate transients observed by linear polarization techniques at Zr-1%Nb alloy

International Nuclear Information System (INIS)

Beran, J.; Cerny, K.

1997-01-01

Momentary corrosion rate of Zr-1%Nb alloy during nonisothermal autoclave experiments at temperature up to 328 deg. C in various solutions was determined by T/R p values (T - absolute temperature, R p - polarization resistance), multiplied by temperature independent conversion factor. This factor was found by comparison of conventional corrosion loss evaluation with electrochemical measurements. Corrosion rate transients in boric acid solutions and in lithium hydroxide differed significantly. Great differences were also found in stabilized corrosion rates at the end of experiments. Temperature irregularities caused considerable changes in corrosion rate. (author). 5 refs, 5 figs, 1 tab

Poster 29. Modelling of ion exchange processes in ultrapure water

International Nuclear Information System (INIS)

Berg, A.; Torstenfelt, B.; Fejes, P.; Foutch, G.L.

1992-01-01

The ion exchange process of the Reactor Water Clean-up (RWCU) system has been studied to better use the maximum possible exchange capacity of the ion exchange resin. Laboratory data have been correlated with computer simulations of the ion exchange process. Data were correlated using a mixed-bed ion exchange model for ultralow ionic concentrations developed at Oklahoma State University. Experimental results of the ion exchange column operation in the concentration range of 10 -3 M boric acid is compared with the simulated performance predicted by the computer model. The model is found to agree reasonably well with the data. (author)

Evaluation of selected parameters on exposure rates in Westinghouse designed nuclear power plants

International Nuclear Information System (INIS)

Bergmann, C.A.

1989-01-01

During the past ten years, Westinghouse under EPRI contract and independently, has performed research and evaluation of plant data to define the trends of ex-core component exposure rates and the effects of various parameters on the exposure rates. The effects of the parameters were evaluated using comparative analyses or empirical techniques. This paper updates the information presented at the Fourth Bournemouth Conference and the conclusions obtained from the effects of selected parameters namely, coolant chemistry, physical changes, use of enriched boric acid, and cobalt input on plant exposure rates. The trends of exposure rates and relationship to doses is also presented. (author)

Stress corrosion of low alloy steels used in external bolting on pressurised water reactors

International Nuclear Information System (INIS)

Skeldon, P.; Hurst, P.; Smart, N.R.

1992-01-01

The stress corrosion cracking (SCC) susceptibility of AISI 4140 and AISI 4340 steels has been evaluated in five environments, three simulating a leaking aqueous boric acid environment and two simulating ambient external conditions ie moist air and salt spray. Both steels were found to be highly susceptible to SCC in all environments at hardnesses of 400 VPN and above. The susceptibility was greatly reduced at hardnesses below 330 VPN but in one environment, viz refluxing PWR primary water, SCC was observed at hardnesses as low as 260VPN. Threshold stress intensities for SCC were frequently lower than those in the literature

Linear titration plot for the determination of boron in the primary coolant of a pressurized water reactor

International Nuclear Information System (INIS)

Midgley, D.; Gatford, C.

1992-01-01

A linear titration plot method has been devised for the determination of boron as boric acid in partly neutralized solution, such as occurs in the primary coolant of pressurized water reactors. The total boron and the alkali in the sample are determined simultaneously. Although it is not essential to add mannitol in this method, it is more accurate when the solution is saturated with mannitol. Comparisons are made with other modes of titration: Gran plots, first and second differential potentiometric titrations and indicator titrations. None of these gives the total boron directly in partly neutralized solutions. (author)

Volumetric and chemical control auxiliary circuit for a PWR primary circuit

International Nuclear Information System (INIS)

Costes, D.

1990-01-01

The volumetric and chemical control circuit has an expansion tank with at least one water-steam chamber connected to the primary circuit by a sampling pipe and a reinjection pipe. The sampling pipe feeds jet pumps controlled by valves. An action on these valves and pumps regulates the volume of the water in the primary circuit. A safety pipe controlled by a flap automatically injects water from the chamber into the primary circuit in case of ruptures. The auxiliary circuit has also systems for purifying the water and controlling the boric acid and hydrogen content [fr

Assessment of the performance of an emergency boration system for anticipated transients without trip faults

International Nuclear Information System (INIS)

Rippon, J.P.; Smedley, C.

1987-01-01

Computer modeling of the emergency boration system (EBS) proposed for the Sizewell B PWR is described in relation to the investigation of two design basis Anticipated Transients Without Trip faults. The performance of the EBS is shown to be dependent on the assumptions made with regard to mixing of RCS coolant with boric acid solution in the tank. An experimental investigation of mixing is described, the results of which are used to validate the computer modeling. Beneficial effects of the EBS in the faults considered are demonstrated in terms of limiting primary pressure, voiding and increasing the shut-down margin

Critical experiments with 4.31 wt % 235U-enriched UO2 rods in highly borated water lattices

International Nuclear Information System (INIS)

Durst, B.M.; Bierman, S.R.; Clayton, E.D.

1982-08-01

A series of critical experiments were performed with 4.31 wt % 235 U enriched UO 2 fuel rods immersed in water containing various concentrations of boron ranging up to 2.55 g/l. The boron was added in the form of boric acid (H 3 BO 3 ). Critical experimental data were obtained for two different lattice pitches wherein the water-to-uranium oxide volume ratios were 1.59 and 1.09. The experiments provide benchmarks on heavily borated systems for use in validating calculational techniques employed in analyzing fuel shipping casks and spent fuel storage systems that may utilize boron for criticality control

Study of new complexes of uranium and comba radical. II-Complexes formed in the presence of OH-, CO3H, CH3-COO-, and B4O7

International Nuclear Information System (INIS)

Vera Palomino, V.; Galiano Sedano, J. A.; Parellada Bellod, R.; Bellido Gonzalez, A.

1975-01-01

Several complexes extracted with CDMBAC organic solutions from uranium aqueous solutions, in presence of sodium and ammonium hydroxides, are studied. These complexes fit to the general formula: U0 2 (OH) n (C[DMBA) n -2 . The uranium extraction in presence of an excess of sodium bicarbonate is also studied. From aqueous solutions of uranyl acetate we have isolated the complex U0 2 (CH 3 -C00) n (CDMBA) n -2. In presence of boric acid and sodium tetraborate an U-CDMBA compound containing boron in its molecule has being obtained by precipitation and liquid-liquid extraction. (Author) 5 refs

Design of a setup for {sup 252}Cf neutron source for storage and analysis purpose

Energy Technology Data Exchange (ETDEWEB)

Hei, Daqian [Department of Nuclear Science and Engineering, College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106 (China); Zhuang, Haocheng [Xi’an Middle School of Shanxi Province, Xi’an 710000 (China); Jia, Wenbao, E-mail: jiawenbao@163.com [Department of Nuclear Science and Engineering, College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106 (China); Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou 215000 (China); Cheng, Can; Jiang, Zhou; Wang, Hongtao [Department of Nuclear Science and Engineering, College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106 (China); Chen, Da [Department of Nuclear Science and Engineering, College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106 (China); Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou 215000 (China)

2016-11-01

{sup 252}Cf is a reliable isotopic neutron source and widely used in the prompt gamma ray neutron activation analysis (PGNAA) technique. A cylindrical barrel made by polymethyl methacrylate contained with the boric acid solution was designed for storage and application of a 5 μg {sup 252}Cf neutron source. The size of the setup was optimized with Monte Carlo code. The experiments were performed and the results showed the doses were reduced with the setup and less than the allowable limit. The intensity and collimating radius of the neutron beam could also be adjusted through different collimator.

Corrosion rate transients observed by linear polarization techniques at Zr-1%Nb alloy

Energy Technology Data Exchange (ETDEWEB)

Beran, J; Cerny, K [ZJS SKODA plc., Pelzen (Czech Republic)

1997-02-01

Momentary corrosion rate of Zr-1%Nb alloy during nonisothermal autoclave experiments at temperature up to 328 deg. C in various solutions was determined by T/R{sub p} values (T - absolute temperature, R{sub p}- polarization resistance), multiplied by temperature independent conversion factor. This factor was found by comparison of conventional corrosion loss evaluation with electrochemical measurements. Corrosion rate transients in boric acid solutions and in lithium hydroxide differed significantly. Great differences were also found in stabilized corrosion rates at the end of experiments. Temperature irregularities caused considerable changes in corrosion rate. (author). 5 refs, 5 figs, 1 tab.

Several perspectives on water-chemical cycles for nuclear power stations equipped with type VVER and RBMK reactors

International Nuclear Information System (INIS)

Mamet, A.P.; Mamet, V.A.; Pashevich, V.I.; Nazarenko, P.N.

1982-01-01

Water-chemical cycles for loops I and II of VVER reactors are discussed. These cycles are mixed ammonia-sodium with a variable concentration of boric acid and ammonia hydrazine with a pH factor of 9.1 +/- 0.1. New water-chemical cycles are considered for use in both existing and new nuclear power plants. Application of these new water-chemical cycles showed produce a significant improvement in operating conditions of nuclear power plants. Upon accumulation of sufficient operating experience with these cycles, it should be possible to raise the issue of revising applicable standard documentation

Impact of load follow operation on the chemistry of the primary and secondary circuit of a pressurized water reactor

International Nuclear Information System (INIS)

Boettcher, F.; Riehm, S.; Bolz, M.; Speck, A.

2012-09-01

Germany decided to abandon nuclear energy and to switch to renewable energy forms. According the renewable energy act renewable energy forms have priority to be fed to the grid. The support of wind and solar energy demands more and more load follow operation of the remaining nuclear power plants to stabilize the grid. This report summarizes first experience with load follow operation in two pressurized water reactors (Philippsburg KKP2 and Neckarwestheim GKNI) with regard to chemistry and radiology. The most important mechanisms of dose rate built up on the primary side are described with Co-60 and Co-58 being the main contributors to dose rate. Goal of the primary side chemistry is to avoid or at least to delay the dose rate built-up as far as achievable. Both reactors are operated according to the modified coordinated B-Li-Chemistry with a pH300 of 7.4 as target value for optimised dose build up delay. By using B-10-enriched boric acid with a boron-10 abundance of 30 at-% (compared to ca. 19.9 at-% in natural boron) the pH 300 target value can be reached earlier in the cycle due to the lower concentration of boric acid required for neutron balancing. In GKNI Zn-injection was started 2005 as a mean of dose reduction. Since 2007 GKNI was operated with load follow operation. In KKP2 load reductions due to wind energy excess are more and more common since 2008. The results of dose rate measurements on the primary side are correlated to primary coolant chemistry and load follow operation. The use of enriched boric acid had a positive (i.e. reducing dose rate) impact on the activity build-up of Co-60 on the loop lines, thus proving the effectiveness of the VGB specifications. After 5 years (one half life time of Co-60) of Zn-injection a positive effect on surface occupancy with nuclides can be determined. The impact of short term deviations from optimal chemical conditions during load follow operation on the activity build up is assessed on the basis of the corrosion

Comparison of two analytical methods for the local quantitative determination of lithium and boron contents in cladding materials

International Nuclear Information System (INIS)

Gavillet, D.; Guenther-Leopold, I.; Martin, M.; Guillong, M.; Hellwig, Ch.; Sell, H.J.

2008-01-01

Pressurized water reactors contain boric acid for reactivity control. As the acidic coolant conditions result in an increased attack of the circuit materials, LiOH is added to render the coolant slightly alkaline. However, LiOH can affect corrosion of the Zr alloy cladding. Thus the Li content in the oxide layers of irradiated fuel rods is of high interest, especially for new alloys (pathfinder rods). At the 'Paul Scherrer Institut' the lithium as well as the boron content in the oxide layers of claddings are determined by Secondary Ion Mass Spectrometry (SIMS). Quantification is performed by direct comparison with a Zircaloy-oxide layer implanted with B and Li. A new and independent method using Laser Ablation Inductively Coupled Plasma Mass Spectrometry was applied to cross-check the SIMS data. (authors)

Water reclamation and reuse

International Nuclear Information System (INIS)

Hrudey, S.E.

1982-01-01

A literature review of wastewater treatment for recycle is presented. Wastewater and activated sludge from the processing of petroleum, shale oil, and from coal conversion and lignite liquefaction have been successfully treated for use as boiler feedwater, cooling water makeup, and steam generation. Acid mine drainage has been treated with lime for use in revegetation of spoil areas. Use of tailings decant water for use in a mill concentrator was reported. Ionizing radiation was effective in disinfecting wastewater makeup to power plant cooling systems. The zero discharge concept was demonstrated in several power plants. Reverse osmosis is reported to be the most economical technology for treatment of cooling tower blowdown. It has the capability of 44% recovery of boric acid and 55% recovery of water from nuclear power plant radioactive wastewater. Included are 402 references

Electrochemical stability of organic electrolytes in supercapacitors: Spectroscopy and gas analysis of decomposition products

Energy Technology Data Exchange (ETDEWEB)

Kurzweil, P.; Chwistek, M. [University of Applied Sciences, Kaiser-Wilhelm-Ring 23, D-92224 Amberg (Germany)

2008-02-01

The fundamental aging mechanisms in double-layer capacitors based on alkylammonium electrolytes in acetonitrile were clarified for the first time. After abusive testing at cell voltages above 4 V, ultracapacitors cast out a crystalline mass of residual electrolyte, organic acids, acetamide, aromatics, and polymer compounds. The mixture could be reproduced by electrolysis. The decomposition products of active carbon electrodes and electrolyte solution after a heat treatment at 70 C were identified by infrared and ultraviolet spectroscopy, liquid and headspace GC-MS, thermogravimetric analysis, and X-ray diffraction. The alkylammonium cation is destroyed by the elimination of ethene. The fluoroborate anion works as source of fluoride and hydrogenfluoride, and boric acid derivates. Acetonitrile forms acetamide, acetic and fluoroacetic acid, and derivates thereof. Due to the catalytic activity of the electrode, heterocyclic compounds are generated in the liquid phase. The etched aluminium support under the active carbon layer is locally destroyed by fluorination. Exploring novel electrolytes, ionic liquids were characterized by impedance spectroscopy. (author)

Rapid preparation of ceramic moulds for medium-sized superalloy castings with magnesia-phosphate-bonded bauxite-mullite investments

Directory of Open Access Journals (Sweden)

Li Tingzhong

2010-11-01

Full Text Available Phosphate-bonded investments have already been widely utilized in dental restoration and micro-casting of artistic products for its outstanding rapid setting and high strength. However, the rapid setting rate of investment slurry has up to now been a barrier to extend the use of such slurry in preparation of medium-sized ceramic moulds. This paper proposes a new process of rapid fabrication of magnesia-phosphate-bonded investment ceramic moulds for medium-sized superalloy castings utilizing bauxite and mullite as refractory aggregates. In order to determine the properties of magnesia-phosphate-bonded bauxite-mullite investments (MPBBMI, a series of experiments were conducted, including modification of the workable time of slurry by liquid(mL/powder(g(L/P ratio and addition of boric acid as retard agent and sodium tri-polyphosphate (STP as strengthening agent, and adjustment of bauxite (g/mullite(g(B/M ratio for mechanical strength. Mechanical vibration was applied to improve initial setting time and fluidity when pouring investment slurry; then an intermediate size ceramic mould for superalloy castings was manufactured by means of this rapid preparing process with MPBBMI material. The results showed that the MPBBMI slurry exhibits proper initial setting time and excellent fluidity when the L/P ratio is 0.64 and the boric acid content is 0.88wt.%. The fired specimens made from the MPBBMI material demonstrated adequate compression strength to withstand impact force of molten metal when the B/M ratio is 0.89 and the STP content is 0.92wt.%. The experimental results confirmed the feasibility of the proposed rapid fabricating process for medium-sized ceramic moulds with MPBBMI material by appropriate measures.

Characterization of solids deposited on the modular caustic-side solvent extraction unit (MCU) coalescer media removed in October 2014

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-03-01

In February 2015, Savannah River National Laboratory (SRNL) received a Strip Effluent (SE) coalescer (FLT-304) from MCU. That coalescer was first installed at MCU in July 2014 and removed in October 2014. While processing approximately 31,400 gallons of strip solution, the pressure drop steadily increased from 1 psi to beyond the administrative limit of 20 psi. The physical and chemical analysis was conducted on this coalescer to determine the mechanism that led to the plugging of this coalescer. Characterization of this coalescer revealed the adsorption of organic containing amines as well as MCU modifier. The amines are probably from the decomposition of the suppressor (TiDG) as well as from bacteria. This adsorption may have changed the surface energetics (characteristics) of the coalescer fibers and therefore, their wetting behavior. A very small amount of inorganic solids were found to have deposited on this coalescer (possibly an artifact of cleaning the coalescer with Boric acid. However, we believe that inorganic precipitation, as has been seen in the past, did not play a role in the high pressure drop rise of this coalescer. With regards to the current practice of reducing the radioactive content of the SE coalescer, it is recommended that future SE coalescer should be flushed with 10 mM boric acid which is currently used at MCU. Plugging of the SE coalescer was most likely due to the formation and accumulation of a water-in-oil emulsion that reduced the overall porosity of the coalescer. There is also evidence that a bimodal oil particle distribution may have entered and deposited in the coalescer and caused the initial increase in pressure drop.

Synthesis of magnetic nanoparticles as a draw solute in forward osmosis membrane process for the treatment of radioactive liquid waste

Energy Technology Data Exchange (ETDEWEB)

Yang, Heeman; Lee, Kune Woo; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

These wastes contain about 0.3 ∼ 0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40 ∼ 90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. As an emerging technology forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination because FO operates at low or no hydraulic pressures. FO is a membrane process in which water flows across a semi-permeable membrane from a feed solution of lower osmotic pressure to a draw solution of higher osmotic pressure. However, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe{sub 3}O{sub 4} nanoparticles can be separated from water by an external magnet field easily. If Fe{sub 3}O{sub 4} nanoparticles are coated with highly soluble organic substances, thus they can be used as a draw solute by concurrently generating high osmotic pressure and easy separation. The carboxylated polyglycerol coated Fe{sub 3}O{sub 4} nanoparticles have been successfully synthesized. The nanoparticles were about 50 nm in diameter and showed the good colloidal stability in aqueous solution. The osmolality and osmotic pressure were enough high to be used as a draw solute in FO. For the future work, we will investigate the performance of our magnetic draw solute in FO to remove boron in the simulated liquid waste.

ODSCC algorithm shows correlation with degradation

International Nuclear Information System (INIS)

Prabhu, P.J.; Rootham, M.W.; Zupetic, N.L.

1998-01-01

Over the last few years we have attempted to develop an algorithm to evaluate the impact of secondary water chemistry on tube degradation in PWR steam generators. Effects of individual factors were assessed and then consolidated to form an algorithm for ODSCC propensity. The algorithm utilizes secondary water chemistry data to calculate ODSCC propensity as a variable named Mega PHI. Prior attempts to correlate algorithm calculations with actual degradation in operating steam generators have resulted in very disappointing results. Recent modifications to the algorithm have demonstrated improved correlation between Mega PHI (calculated result from the algorithm) and actual degradation history from operating plants. The recent modifications involve the inclusion of the synergistic effect of boric acid application of secondary water and of high silica concentration in steam generator toward inhibiting ODSCC. Data from several plants with mill annealed alloy 600 tubing in the steam generators and operating with the primary coolant inlet temperature in the range of 608 to 624 degrees F (320 to 329 degrees C) were evaluated and the results compared with actual degradation reported from in-service inspections. The population of plants includes those with very few tubes repaired and those with hundreds of tubes repaired due to ODSCC at tube support plates. The observation of substantial correlation between the algorithm calculation and actual degradation signifies the roles of boric acid and silica in inhibiting ODSCC. It is recommended that further evaluation of the role of these chemical species be performed using more extensive data. The goal is to modify secondary water chemistry guidelines with the ultimate aim of minimizing corrosion of steam generator tubes. (author)

Super Dielectric Materials.

Science.gov (United States)

Fromille, Samuel; Phillips, Jonathan

2014-12-22

Evidence is provided here that a class of materials with dielectric constants greater than 10⁵ at low frequency (dielectric materials (SDM), can be generated readily from common, inexpensive materials. Specifically it is demonstrated that high surface area alumina powders, loaded to the incipient wetness point with a solution of boric acid dissolved in water, have dielectric constants, near 0 Hz, greater than 4 × 10⁸ in all cases, a remarkable increase over the best dielectric constants previously measured for energy storage capabilities, ca. 1 × 10⁴. It is postulated that any porous, electrically insulating material (e.g., high surface area powders of silica, titania, etc. ), filled with a liquid containing a high concentration of ionic species will potentially be an SDM. Capacitors created with the first generated SDM dielectrics (alumina with boric acid solution), herein called New Paradigm Super (NPS) capacitors display typical electrostatic capacitive behavior, such as increasing capacitance with decreasing thickness, and can be cycled, but are limited to a maximum effective operating voltage of about 0.8 V. A simple theory is presented: Water containing relatively high concentrations of dissolved ions saturates all, or virtually all, the pores (average diameter 500 Å) of the alumina. In an applied field the positive ionic species migrate to the cathode end, and the negative ions to the anode end of each drop. This creates giant dipoles with high charge, hence leading to high dielectric constant behavior. At about 0.8 V, water begins to break down, creating enough ionic species to "short" the individual water droplets. Potentially NPS capacitor stacks can surpass "supercapacitors" in volumetric energy density.

Characterization of Chemically-Induced Bacterial Ghosts (BGs Using Sodium Hydroxide-Induced Vibrio parahaemolyticus Ghosts (VPGs

Directory of Open Access Journals (Sweden)

Hyun Jung Park

2016-11-01

Full Text Available Acellular bacterial ghosts (BGs are empty non-living bacterial cell envelopes, commonly generated by controlled expression of the cloned lysis gene E of bacteriophage PhiX174. In this study, Vibrio parahaemolyticus ghosts (VPGs were generated by chemically-induced lysis and the method is based on minimum inhibitory concentration (MIC of sodium hydroxide (NaOH, acetic acid, boric acid, citric acid, maleic acid, hydrochloric acid, and sulfuric acid. The MIC values of the respective chemicals were 3.125, 6.25, <50.0, 25.0, 6.25, 1.56, and 0.781 mg/mL. Except for boric acid, the lysis efficiency reached more than 99.99% at 5 min after treatment of all chemicals. Among those chemicals, NaOH-induced VPGs appeared completely DNA-free, which was confirmed by quantitative real-time PCR. Besides, lipopolysaccharides (LPS extracted from the NaOH-induced VPGs showed no distinctive band on SDS-PAGE gel after silver staining. On the other hand, LPS extracted from wild-type bacterial cells, as well as the organic acids-induced VPGs showed triple major bands and LPS extracted from the inorganic acids-induced VPGs showed double bands. It suggests that some surface structures in LPS of the NaOH-induced VPGs may be lost, weakened, or modified by the MIC of NaOH. Nevertheless, Limulus amoebocyte lysate assay revealed that there is no significant difference in endotoxic activity between the NaOH-induced VPGs and wild-type bacterial cells. Macrophages exposed to the NaOH-induced VPGs at 0.5 × 106 CFU/mL showed cell viability of 97.9%, however, the MIC of NaOH did not reduce the cytotoxic effect of wild-type bacterial cells. Like Escherichia coli LPS, the NaOH-induced VPGs are an excellent activator of pro-inflammatory cytokines (IL-1β and iNOS, anti-inflammatory cytokine (IL-10, and dual activities (IL-6 in the stimulated macrophage cells. On the other hand, the induction of TNF-α mRNA was remarkable in the macrophages exposed with wild-type cells. Scanning

Division of waste management programs. Progress report, July--December 1977

International Nuclear Information System (INIS)

Lerch, R.E.; Allen, C.R.

1978-07-01

An acid fractionator and acid recycle equipment were added to the Radioactive Acid Digestion Test Unit (RADTU). The first simulated waste was processed through RADTU in November. By the end of December RADTU had been operated up to its design capacity of 4 kg of waste/hour without major problems. The unit was operated for 23 hours and processed 62 kg of waste during initial shakedown testing. Borosilicate glass specimens, containing up to 33 wt percent acid digestion residue, were made after the sulfur was removed. The glass had a density of 2.6 g/cm 3 and produced a two-fold decrease in residue volume. During tests on the solubility of thorium oxide in the acid digestion system, thorium oxide was converted to a form, presumably thorium sulfate, that was soluble in either dilute nitric acid or water. Thorium sulfate has approximately the same solubility in acid digestion as plutonium, about 0.1 g/l, and strontium from the boric acid-cement samples were found to be excessively high during 14-day leach tests. Leach rates of cesium and strontium from the sodium sulfate-cement samples were much lower. Leach rate tests were also performed on mercuric iodate immobilized in cement. 12 figs., 10 tables

Poster 34. Monitoring of soluble species in the NPTEC SCEPTRE loop

International Nuclear Information System (INIS)

Eley, C.D.; Thomas, D.M.; Libaert, D.F.; Cattell, R.A.; Garbett, K.; Woolsey, I.S.

1992-01-01

Soluble transition metal ion and other species were measured in the coolant of the SCEPTRE Loop under PWR primary circuit conditions typical of the hot functional test and normal load operation. Good consistency between lines was observed for stainless steel sample lines with relatively high linear flow rates, rapid cooling to near ambient temperature and PTFE lining downstream of the cooler. Phenomenological conditioning times of the order of 100 hours for soluble transition metal species were determined for this type of sampling system. The behaviour of soluble transition metal species in a static, aerated stainless steel tank containing boric acid solutions was also investigated. (author)

Treatment of some power plant waters

International Nuclear Information System (INIS)

Konecny, C.; Vanura, P.; Franta, P.; Marhol, M.; Tejnecky, M.; Fidler, J.

1987-01-01

Major results are summed up obtained in 1986 in the development of techniques for the treatment of coolant in the fuel transport and storage tank, of reserve coolant in the primary circuit and of waste water from the special nuclear power plant laundries, containing new washing agent Alfa-DES. A service test of the filter filled with Czechoslovak-made cation exchanger Ostion KSN in the boric acid concentrate filter station showed that the filter can be used in some technological circuits of nuclear power plants. New decontamination agents are also listed introduced in production in Czechoslovakia for meeting the needs of nuclear power plants. (author). 6 refs

Solidification of aqueous radioactive waste using insoluble compounds of magnesium oxide

International Nuclear Information System (INIS)

Carlson, J.E.

1986-01-01

A process is described for the treatment of radioactive waste which comprises: (a) first adding, under continuous agitation, a sufficient amount of a powdered magnesium oxide or magnesium hydroxide to an aqueous radioactive waste solution containing boric acid, the temperature of the water solution being 55-95 degrees C. to produce a magnesium borate derivative; (b) adding cement, under continuous agitation, to the magnesium borate derivative; and (c) then adding, under continuous agitation, after the cement has been dispersed, a sufficient amount of a compound selected from the group consisting of calcium oxide and calcium hydroxide to (b) to produce a gel matrix structure

Photocatalysis of zinc oxide nanotip array/titanium oxide film heterojunction prepared by aqueous solution deposition

Science.gov (United States)

Lee, Ming-Kwei; Lee, Bo-Wei; Kao, Chen-Yu

2017-05-01

A TiO2 film was prepared on indium tin oxide (ITO)/glass by aqueous solution deposition (ASD) with precursors of ammonium hexafluoro-titanate and boric acid at 40 °C. The photocatalysis of annealed TiO2 film increases with increasing growth time and decreases with increasing growth times longer than 60 min. A ZnO nanotip array was prepared on ZnO seed layer/TiO2 film/glass by aqueous solution deposition with precursors of zinc nitrate and ammonium hydroxide at 70 °C. The photocatalysis of ASD-ZnO/ASD-TiO2 film/ITO glass can be better than that of P25.

Falcon II seminar, Winfrith Technology Centre, 13-14 March 1991

International Nuclear Information System (INIS)

Bennett, P.J.; Bowsher, B.R.

1991-05-01

Falcon was designed to study the transport of fission products released from both simulant and trace-irradiated fuel through a circuit simulating the upper plenum, hot-leg structures and the containment. Various sophisticated analytical techniques were used to provide information on the chemical species and physical forms of the released material. Twenty integral experiments of increasing complexity were successfully completed. The initial experiments were designed to characterise the thermal-hydraulics of the system, while the final tests included: (i) aerosols from Ag-In-Cd control rod and boric acid, (ii) a source of fission products, (iii) a painted surface and aqueous sump in the containment vessel to study iodine chemistry. (author)

Study of the self-regulating properties of a WWER reactor

International Nuclear Information System (INIS)

Filo, J.; Trnkusz, J.; Polak, V.

1979-01-01

The results of a self-regulation experiment carried out on the V-1 reactor in Czechoslovakia in the period of the start-up are presented. The kinetic state of the reactor was modified by varying the position of the automatic control rods, the power of the turbogenerators and by switching off a main pump in the primary circuit, on power levels of 35, 55, 75 and 90%. The important thermal parameters of the reactor, the electric power of the turbogenerators, the neutron flux, the position of the automatic control rod group and the concentration of the boric acid in the coolant have been measured. (R.J.)

X-ray fluorescence analysis of praseodymium oxide/oxalate for rare earth impurities

International Nuclear Information System (INIS)

Chandola, L.C.; Mohile, A.N.

1976-01-01

A method for the determination of lanthanum, cerium, neodymium and samarium oxides in praseodymium oxide is described. The sample in the oxalate form is mixed with boric acid binder in the weight ratio of 1:1 and pressed into a pellet. The pellet is irradiated by X-rays from a tungsten tube and fluorescent X-rays are dispersed by a LiF (200) crystal in a Philips semiautomatic X-ray fluorescence spectrometer. The intensity of the characteristic X-rays of the impurity elements is measured by a flow proportional counter at selected 20 angles. The minium determination limit is 0.01% for all impurities. (author)

The treatment of low level effluents by flocculation and settling at the Chooz nuclear power plant

International Nuclear Information System (INIS)

Petteau, J.L.; Roofthooft, R.

1989-01-01

At the Chooz plant, radioactive effluents were formerly treated by evaporation, but because throughput was low, another method was studied. After laboratory tests, a 500 L/h flocculation and settling pilot plant was constructed, followed later by a 5 m 3 /h installation. The main isotopes eliminated are caesium-134 and caesium-137. Flocculation with copper ferrocyanide reduces the total activity to less than 500 Bq/L. The installation described in the paper was commissioned in 1984 and has been in industrial operation since 1985, processing all types of effluent. The evaporator can be set aside for boric acid recovery. (author). 3 figs, 1 tab

Study of new complexes of uranium and comba radical. II-Complexes formed in the presence of OH{sup -}, CO{sub 3}H{sup -}, CH{sub 3}-COO{sup -}, and B{sub 4}={sub 7}; Estudio de nuevos complejos entre uranio y el radical CADMBA. II. Complejos formados en presencia de OH{sup -}, CO{sub 3}H, CH{sub 3}-COO{sup -} y B{sub 4}O{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Vera Palomino, V; Galiano Sedano, J A; Parellada Bellod, R; Bellido Gonzalez, A

1975-07-01

Several complexes extracted with CDMBAC organic solutions from uranium aqueous solutions, in presence of sodium and ammonium hydroxides, are studied. These complexes fit to the general formula: U0{sub 2}(OH){sub n}(CDMBA){sub n}-2 . The uranium extraction in presence of an excess of sodium bicarbonate is also studied. From aqueous solutions of uranyl acetate we have isolated the complex U0{sub 2}(CH{sub 3}-C00){sub n} (CDMBA){sub n}-2. In presence of boric acid and sodium tetraborate an U-CDMBA compound containing boron in its molecule has being obtained by precipitation and liquid-liquid extraction. (Author) 5 refs.

Development and study the performance of PBA cladding modified fiber optic intrinsic biosensor for urea detection

Energy Technology Data Exchange (ETDEWEB)

Botewad, S. N.; Pahurkar, V. G.; Muley, G. G., E-mail: gajananggm@yahoo.co.in [Department of Physics, Sant Gadge Baba Amravati University, Amravati, Maharashtra, India-444602 (India)

2016-05-06

The fabrication and study of a cladding modified fiber optic intrinsic urea biosensor based on evanescent wave absorbance has been presented. The sensor was prepared using cladding modification technique by removing a small portion of cladding of an optical fiber and modifying with an active cladding of porous polyaniline-boric acid (PBA) matrix to immobilize enzyme-urease through cross-linking via glutaraldehyde. The nature of as-synthesized and deposited PBA film on fiber optic sensing element was studied by ultraviolet-visible (UV-vis) spectroscopy and X-ray diffraction (XRD) analysis. The performance of the developed sensor was studied for different urea concentrations in solutions prepared in phosphate buffer.

Chemical Processing Department monthly report for April 1958

Energy Technology Data Exchange (ETDEWEB)

Warren, J.H.

1958-05-21

The separations plants operated on schedule, and Pu production exceeded commitment. UO{sub 3} production and shipments were also ahead of schedule. Purex operation under pseudo two-cycle conditions (elimination of HS and 1A columns, co-decontamination cycle concentrator HCP) was successful. Final U stream was 3{times} lower in Pu than ever before; {gamma} activity in recovered HNO{sub 3} was also low. Four of 6 special E metal batches were processed through Redox and analyzed. Boric acid is removed from solvent extraction process via aq waste. The filter in Task II hydrofluorinator was changed from carbon to Poroloy. Various modifications to equipment were made.

Gravimetric screening method for fungal decay of paper: inoculation with Trametes versicolor.

Science.gov (United States)

Råberg, Ulrika; Hafrén, Jonas

2009-10-01

The European standard test EN 113 for fungal degradation of solid wood has been adapted for degradation of paper by white rot fungus (Trametes versicolor). Fungal degradation of paper sheets may potentially be used for screening different wood preservatives on paper instead of solid wood. The paper samples showed higher relative mass losses compared to wood, and samples pretreated with boric acid, copper sulfate and polymerized linseed oil were successfully tested for biodegradation using the paper sheet method. The results on paper degradation were compared with wood, both as wood blocks (according to standard test) and wood cut in sections forming layered structures mimicking paper layers.

Spectroscopic Studies of the Chan-Lam Amination: A Mechanism-Inspired Solution to Boronic Ester Reactivity.

Science.gov (United States)

Vantourout, Julien C; Miras, Haralampos N; Isidro-Llobet, Albert; Sproules, Stephen; Watson, Allan J B

2017-04-05

We report an investigation of the Chan-Lam amination reaction. A combination of spectroscopy, computational modeling, and crystallography has identified the structures of key intermediates and allowed a complete mechanistic description to be presented, including off-cycle inhibitory processes, the source of amine and organoboron reactivity issues, and the origin of competing oxidation/protodeboronation side reactions. Identification of key mechanistic events has allowed the development of a simple solution to these issues: manipulating Cu(I) → Cu(II) oxidation and exploiting three synergistic roles of boric acid has allowed the development of a general catalytic Chan-Lam amination, overcoming long-standing and unsolved amine and organoboron limitations of this valuable transformation.

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

Science.gov (United States)

2013-04-03

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

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

Science.gov (United States)

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

2010-06-01

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

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...

[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.

Personal monitors for inorganic gases. Final report, 28 September 1978-31 August 1979

Energy Technology Data Exchange (ETDEWEB)

West, P.W.

1979-01-01

Successful passive sampling techniques were developed for ammonia and hydrogen-cyanide. For ammonia the collection of the sample required permeation through a silicone membrane into boric acid. Spectrophotometric determination of the ammonia was carried out using Nessler's reagent or potentiometrical means with an ion-selective electrode. Linearity was demonstrated using the monitor over concentration ranges of less than 10 to over 160 parts per million. The ammonia monitor was relatively free from interference by amines and could be used in a badge-type monitor, as it was very light in weight and compact. The hydrogen-cyanide monitor functioned by permeation through a silicone membrane. The permeated gas was stabilized in sodium hydroxide and determined by means of a standard pyridine/barbituric acid colorimetric method. A detection limit of 10 parts per billion for an 8-hour exposure was obtained. Difficulties were encountered in developing a sampler for hydrogen sulfide.

The Effect of Particle Size of Wollastonite Filler on Thermal Performance of Intumescent Fire Retardant Coating

Directory of Open Access Journals (Sweden)

Zia-ul-Mustafa M.

2014-07-01

Full Text Available Intumescent Fire retardant coatings (IFRC’s are one of the simplest ways to protect substrates exposed to fire. In this study, Wollastonite (W filler of two different particle sizes were used to determine the fire performance of intumescent fire retardant coating. The basic ingredients of the coating were ammonium poly-phosphate (APP as acid source, expandable graphite (EG as carbon source, melamine (MEL as blowing agent in epoxy binder, boric acid as additive and hardener as curing agent. A series of coating formulations were developed by using different weight percentages of both sized Wollastonite fillers. The coated steel substrate samples were tested for fire performance using Bunsen burner and char expansion was measured using furnace fire test. A Comparison of the coatings thermal performance was determined. Wollastonite containing filler particle size 10 μm showed better thermal performance than formulations containing filler’s particle size 44 μm.

Method of denitrification and stabilization of radioactive aqueous solutions of radioisotope nitrates

International Nuclear Information System (INIS)

Pecak, V.; Matous, V.

1983-01-01

The method is solved of denitrification and of the stabilization of aqueous solutions of radioactive isotopes produced during the reprocessing of nuclear fuel. The aqueous solution is first mixed with the vitreous component, most frequently phosphoric acid, ammonium phosphate or boric acid and if needed with the addition of alkalis, possibly with clarifying or anti-foam components, e.g., arsenic trioxide, antimony or cerium oxide. The mixture is further adjusted with ammonia to pH 5 - 9. The liquid mixture is then thermally and pyrolytically processed, e.g., by calcinator or fluid-bed reactor or by pot melting at temperatures of 3O0 to 900 degC while of a powder product or glass melt is formed in the presence of gaseous emissions composed of nitrous oxide - nitrogen. The resulting product is further processed by containerization or is sealed in a metal matrix. (B.S.)

Method of solidifying radioactive liquid wastes

International Nuclear Information System (INIS)

Uetake, Naoto; Kawamura, Fumio; Kikuchi, Makoto; Fukazawa, Tetsuo.

1983-01-01

Purpose: To enable to confine the volatiling ingredients such as cesium in liquid wastes safely in glass solidification products while suppressing the volatilization thereof. Method: Acid salt of tetravalent metal such as titanium phosphate has an intense selective adsorption property to cesium. So liquid wastes stored in a high level liquid wastes tank is mixed with titanium phosphate gels stored in an adsorbent tank, then supplied to a mixer and mixed with a sodium silicate solution stored in a sodium silicate storage tank and boric acid stored in an additive tank, into gel-like state. The gel-like material thus formed is supplied to a drier. After being dried at a temperature of 200sup(o)C - 300sup(o)C, the material is melted under heating at a temperature of 1000sup(o)C - 1100sup(o)C, and then cooled to solidify. (Horiuchi, T.)

JT-60SA vacuum vessel manufacturing and assembly

Energy Technology Data Exchange (ETDEWEB)

Masaki, Kei, E-mail: masaki.kei@jaea.go.jp [Japan Atomic Energy Agency, Naka, Ibaraki-ken 311-0193 (Japan); Shibama, Yusuke K.; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira [Japan Atomic Energy Agency, Naka, Ibaraki-ken 311-0193 (Japan)

2012-08-15

Highlights: Black-Right-Pointing-Pointer The design of the JT-60SA vacuum vessel body was completed with the demonstration of manufacturing procedure by the mock-up fabrication of the 20 Degree-Sign upper half of VV. Black-Right-Pointing-Pointer The actual VV manufacturing has started since November 2009. Black-Right-Pointing-Pointer The first product of the VV 40 Degree-Sign sector was completed in May 2011. Black-Right-Pointing-Pointer A basic VV assembly scenario and procedure were studied to complete the 360 Degree-Sign VV including positioning method and joint welding. - Abstract: The JT-60SA vacuum vessel (VV) has a D-shaped poloidal cross section and a toroidal configuration with 10 Degree-Sign segmented facets. A double wall structure is adopted to ensure high rigidity at operational load and high toroidal one-turn resistance. The material is 316L stainless steel with low cobalt content (<0.05%). The design temperatures of the VV at plasma operation and baking are 50 Degree-Sign C and 200 Degree-Sign C, respectively. In the double wall, boric-acid water is circulated at plasma operation to reduce the nuclear heating of the superconducting magnets. For baking, nitrogen gas is circulated in the double wall after draining of the boric-acid water. The manufacturing of the VV started in November 2009 after a fundamental welding R and D and a trial manufacturing of 20 Degree-Sign upper half mock-up. The manufacturing of the first VV 40 Degree-Sign sector was completed in May 2011. A basic concept and required jigs of the VV assembly were studied. This paper describes the design and manufacturing of the vacuum vessel. A plan of VV assembly in torus hall is also presented.

Biodegradation testing of solidified low-level waste streams

International Nuclear Information System (INIS)

Piciulo, P.L.; Shea, C.E.; Barletta, R.E.

1985-05-01

The NRC Technical Position on Waste Form (TP) specifies that waste should be resistant to biodegradation. The methods recommended in the TP for testing resistance to fungi, ASTM G21, and for testing resistance to bacteria, ASTM G22, were carried out on several types of solidified simulated wastes, and the effect of microbial activity on the mechanical strength of the materials tested was examined. The tests are believed to be sufficient for distinguishing between materials that are susceptible to biodegradation and those that are not. It is concluded that failure of these tests should not be regarded of itself as an indication that the waste form will biodegrade to an extent that the form does not meet the stability requirements of 10 CFR Part 61. In the case of failure of ASTM G21 or ASTM G22 or both, it is recommended that additional data be supplied by the waste generator to demonstrate the resistance of the waste form to microbial degradation. To produce a data base on the applicability of the biodegradation tests, the following simulated laboratory-scale waste forms were prepared and tested: boric acid and sodium sulfate evaporator bottoms, mixed-bed bead resins and powdered resins each solidified in asphalt, cement, and vinyl ester-styrene. Cement solidified wastes supported neither fungal nor bacterial growth. Of the asphalt solidified wastes, only the forms of boric acid evaporator bottoms did not support fungal growth. Bacteria grew on all of the asphalt solidified wastes. Cleaning the surface of these waste forms did not affect bacterial growth and had a limited effect on the fungal growth. Only vinyl esterstyrene solidified sodium sulfate evaporator bottoms showed viable fungi cultures, but surface cleaning with solvents eliminated fungal growth in subsequent testing. Some forms of all the waste streams solidified in vinyl ester-styrene showed viable bacteria cultures. 13 refs., 12 tabs

Super Dielectric Materials

Directory of Open Access Journals (Sweden)

Samuel Fromille

2014-12-01

Full Text Available Evidence is provided here that a class of materials with dielectric constants greater than 105 at low frequency (<10−2 Hz, herein called super dielectric materials (SDM, can be generated readily from common, inexpensive materials. Specifically it is demonstrated that high surface area alumina powders, loaded to the incipient wetness point with a solution of boric acid dissolved in water, have dielectric constants, near 0 Hz, greater than 4 × 108 in all cases, a remarkable increase over the best dielectric constants previously measured for energy storage capabilities, ca. 1 × 104. It is postulated that any porous, electrically insulating material (e.g., high surface area powders of silica, titania, etc., filled with a liquid containing a high concentration of ionic species will potentially be an SDM. Capacitors created with the first generated SDM dielectrics (alumina with boric acid solution, herein called New Paradigm Super (NPS capacitors display typical electrostatic capacitive behavior, such as increasing capacitance with decreasing thickness, and can be cycled, but are limited to a maximum effective operating voltage of about 0.8 V. A simple theory is presented: Water containing relatively high concentrations of dissolved ions saturates all, or virtually all, the pores (average diameter 500 Å of the alumina. In an applied field the positive ionic species migrate to the cathode end, and the negative ions to the anode end of each drop. This creates giant dipoles with high charge, hence leading to high dielectric constant behavior. At about 0.8 V, water begins to break down, creating enough ionic species to “short” the individual water droplets. Potentially NPS capacitor stacks can surpass “supercapacitors” in volumetric energy density.

Pengawetan Kayu Gubal Jati Secara Rendaman Dingin dengan Pengawet Boron untuk Mencegah Serangan Rayap Kayu Kering (Cryptotermes cynocephalus Light.

Directory of Open Access Journals (Sweden)

Afif Sumaryanto

2015-10-01

The utilization of younger teakwood has a disadvantage, which is the sapwood is more susceptible to dry wood termites as it has less natural durability. Boric acid and borax are inexpensive preservatives, which contain boron as the active material. Those preservatives are also easy to be obtained as well as do not produce smells and the wood discoloration. The experiment materials were the sapwood parts from teak boards obtained from the felled trees in the community forest of Kali Bawang, Kulon Progo. A complete randomized block design was arranged in a factorial with two factors, which were the type of preservatives (boric acid and borax in 5% concentration and duration of cold soaking (12, 24, 36, and 48 hours. To examine the durability of sample, dry wood termites (Cryptotermes cynocephalus Light were used. The results showed that the average values of absorption, retention, and depth of penetration were 33.09 to 70.77 kg/m3, 3.81 to 10.77 kg/m3, and 2.34 to 3.86 mm, respectively. The average values of termite mortality during 2 weeks and 4 weeks were 46.33 to 53 %, 82.67 to 94.33 %. Weight reduction and degree of the damage were, 560 to 570 mg, and 30.34 to 31.27 %, respectively. By analysis of variance, there was an interaction between the type of preservatives and the duration of cold soaking factors, which affected significantly the termite mortality. Type of preservative affected significantly the absorption and penetration. Further, the duration of cold soaking affected significantly the level of absorption, retention and penetration. The application of preservatives could reduce the mass loss of specimens until 70 % as well as to give higher levels of mortality rate (87-92 % compared to that of untreated one.

Methods for separating boron from borated paraffin wax and its determination by ion chromatography

International Nuclear Information System (INIS)

Jeyakumar, S.

2015-01-01

Boron compounds are found to be useful in shielding against high-energy neutrons. In radiotherapy treatments, in order to protect occupational workers and patients from the undesirable neutron and gamma doses, paraffin wax containing B 4 C/boric acid is used. Low-level borate wastes generated from the nuclear power plants have been immobilized with paraffin wax using a concentrate waste drying system (CWDS). Borated paraffin waxes are prepared by mixing calculated amounts of either boric acid or boron carbide with the molten wax. This necessitates the determination of boron at different locations in order to check the homogeneous distribution of B over the borated wax. The determination of boron in nuclear materials is inevitable due to its high neutron absorption cross section. For the determination of boron in borated waxes, not many methods have been reported. A method based on the pyrohydrolysis extraction of boron and its quantification with ion chromatography was proposed for paraffin waxes borated with H 3 BO 3 and B 4 C. The B 4 C optimum pyrohydrolysis conditions were identified. Wax samples were mixed with U 3 O 8 , which prevents the sample from flare up, and also accelerates the extraction of boron. Pyrohydrolysis was carried out with moist O 2 at 950℃ for 60 and 90 min for wax with H 3 BO 3 and wax with B 4 C, respectively. Two simple methods of separation based on alkali extraction and melting wax in alkali were also developed exclusively for wax with H 3 BO 3 . In all the separations, the recovery of B was above 98%. During IC separation, B was separated as boron-mannitol anion complex. Linear calibration was obtained between 0.1 and 50 ppm of B, and LOD was calculated as 5 ppb (S/N=3). The reproducibility was better than 5% (RSD)

Modified hot-conditioning of PHT system surfaces of PHWRs

Energy Technology Data Exchange (ETDEWEB)

Venkateswaran, G [Bhabha Atomic Research Centre, Trombay, Bombay (India)

1997-02-01

The increased awareness on the importance of controlling activity transport and radiation buildup on out-of-core surfaces of water cooled nuclear reactors is leading to a host of measures both from chemistry as well as engineering sides being undertaken. Passivation of the surfaces of structural materials is one such. Pressurised Heavy Water Reactors of CANDU design use large surface area of carbon steel alloy in the Primary Heat Transport System. Hot-conditioning of the PHT system with deoxygenated light water at temperatures {approx_equal} 473 - 523 K during commissioning stage is done to form a protective magnetite film on the surfaces of carbon steel essentially to guard this material from corrosion during the intervening period between initial commissioning and first fuel loading and achieving nuclear heat. However, a need is felt to improve the quality of this magnetite film and control the crud release so that the twin objectives of controlling the corrosion of carbon steel and reducing a possible deposition of corrosion products on surfaces of fuel clad could be achieved. Laboratory static autoclave investigations have been carried out on the formation of protective magnetite film on carbon steel at 473 K, pH 10 (pH at 298 K) deoxygenated aqueous solutions of chelants like HEDTA, DTPA, NTA apart from EDTA. Additionally, influence of AVT chemicals like hydrazine, cyclohexylamine, morpholine and additives like glucose, boric acid has been studied. The data have been compared with the standard procedure of hot-conditioning namely with simple LiOH. It is found that chelants increase the base metal loss but the oxide formed is more protective than the one formed under simple LiOH treatment. The efficiency of passivation is greatly enhanced by hydrazine and boric acid while it is adversely affected by glucose. AVT chemicals acts as effective corrosion inhibitors. (author). 14 refs, 2 figs, 4 tabs.

Modified hot-conditioning of PHT system surfaces of PHWRs

International Nuclear Information System (INIS)

Venkateswaran, G.

1997-01-01

The increased awareness on the importance of controlling activity transport and radiation buildup on out-of-core surfaces of water cooled nuclear reactors is leading to a host of measures both from chemistry as well as engineering sides being undertaken. Passivation of the surfaces of structural materials is one such. Pressurised Heavy Water Reactors of CANDU design use large surface area of carbon steel alloy in the Primary Heat Transport System. Hot-conditioning of the PHT system with deoxygenated light water at temperatures ≅ 473 - 523 K during commissioning stage is done to form a protective magnetite film on the surfaces of carbon steel essentially to guard this material from corrosion during the intervening period between initial commissioning and first fuel loading and achieving nuclear heat. However, a need is felt to improve the quality of this magnetite film and control the crud release so that the twin objectives of controlling the corrosion of carbon steel and reducing a possible deposition of corrosion products on surfaces of fuel clad could be achieved. Laboratory static autoclave investigations have been carried out on the formation of protective magnetite film on carbon steel at 473 K, pH 10 (pH at 298 K) deoxygenated aqueous solutions of chelants like HEDTA, DTPA, NTA apart from EDTA. Additionally, influence of AVT chemicals like hydrazine, cyclohexylamine, morpholine and additives like glucose, boric acid has been studied. The data have been compared with the standard procedure of hot-conditioning namely with simple LiOH. It is found that chelants increase the base metal loss but the oxide formed is more protective than the one formed under simple LiOH treatment. The efficiency of passivation is greatly enhanced by hydrazine and boric acid while it is adversely affected by glucose. AVT chemicals acts as effective corrosion inhibitors. (author). 14 refs, 2 figs, 4 tabs

Effectiveness of Preanalytic Practices on Contamination and Diagnostic Accuracy of Urine Cultures: a Laboratory Medicine Best Practices Systematic Review and Meta-analysis

Science.gov (United States)

Franek, Jacob; Leibach, Elizabeth K.; Weissfeld, Alice S.; Kraft, Colleen S.; Sautter, Robert L.; Baselski, Vickie; Rodahl, Debra; Peterson, Edward J.; Cornish, Nancy E.

2015-01-01

SUMMARY Background. Urinary tract infection (UTI) in the United States is the most common bacterial infection, and urine cultures often make up the largest portion of workload for a hospital-based microbiology laboratory. Appropriately managing the factors affecting the preanalytic phase of urine culture contributes significantly to the generation of meaningful culture results that ultimately affect patient diagnosis and management. Urine culture contamination can be reduced with proper techniques for urine collection, preservation, storage, and transport, the major factors affecting the preanalytic phase of urine culture. Objectives. The purposes of this review were to identify and evaluate preanalytic practices associated with urine specimens and to assess their impact on the accuracy of urine culture microbiology. Specific practices included collection methods for men, women, and children; preservation of urine samples in boric acid solutions; and the effect of refrigeration on stored urine. Practice efficacy and effectiveness were measured by two parameters: reduction of urine culture contamination and increased accuracy of patient diagnosis. The CDC Laboratory Medicine Best Practices (LMBP) initiative's systematic review method for assessment of quality improvement (QI) practices was employed. Results were then translated into evidence-based practice guidelines. Search strategy. A search of three electronic bibliographic databases (PubMed, SCOPUS, and CINAHL), as well as hand searching of bibliographies from relevant information sources, for English-language articles published between 1965 and 2014 was conducted. Selection criteria. The search contained the following medical subject headings and key text words: urinary tract infections, UTI, urine/analysis, urine/microbiology, urinalysis, specimen handling, preservation, biological, preservation, boric acid, boric acid/borate, refrigeration, storage, time factors, transportation, transport time, time delay

The acidic functional groups of humic acid

Energy Technology Data Exchange (ETDEWEB)

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

1983-09-01

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