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1

Development of Acetic Acid Removal Technology for the UREX+Process  

Energy Technology Data Exchange (ETDEWEB)

It is imperative that acetic acid is removed from a waste stream in the UREX+process so that nitric acid can be recycled and possible interference with downstreatm steps can be avoidec. Acetic acid arises from acetohydrozamic acid (AHA), and is used to suppress plutonium in the first step of the UREX+process. Later, it is hydrolyzed into hydroxyl amine nitrate and acetic acid. Many common separation technologies were examined, and solvent extraction was determined to be the best choice under process conditions. Solvents already used in the UREX+ process were then tested to determine if they would be sufficient for the removal of acetic acid. The tributyl phosphage (TBP)-dodecane diluent, used in both UREX and NPEX, was determined to be a solvent system that gave sufficient distribution coefficients for acetic acid in addition to a high separation factor from nitric acid.

Robert M. Counce; Jack S. Watson

2009-06-30

2

Adsorptive Membranes vs. Resins for Acetic Acid Removal from Biomass Hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

Acetic acid is a compound commonly found in hemicellulosic hydrolysates. This weak acid strongly influences the bioconversion of sugar containing hydrolysates. Previous investigators have used anion exchange resins for acetic acid removal from different hemicellulosic hydrolysates. In this study, the efficiency of an anion exchange membrane was compared to that of an anion exchange resin, for acetic acid removal from a DI water solution and an acidic hemicellulose hydrolysate pretreated using two different methods. Ion exchange membranes and resins have very different geometries. Here the performance of membranes and resins is compared using two dimensionless parameters, the relative mass throughput and chromatographic bed number. The relative mass throughput arises naturally from the Thomas solution for ion exchange. The results show that the membrane exhibit better performance in terms of capacity, and loss of the desired sugars. In addition acetic acid may be eluted at a higher concentration from the membrane thus leading to the possibility of recovery and re-use of the acetic acid.

Han, B.; Carvalho, W.; Canilha, L.; da Silva, S. S.; e Silva, J. B. A.; McMillan, J. D.; Wickramasinghe, S. R.

2006-01-01

3

Effects of acetic acid, ethanol and SO2 on the removal of volatile acidity from acidic wines by two Saccharomyces cerevisiae commercial strains  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Herein we report the influence of different combinations of initial concentration of acetic acid and ethanol on the removal of acetic acid from acidic wines by two commercial Saccharomyces cerevisiae strains S26 and S29. Both strains reduced the volatile acidity of an acidic wine (1.0 g l-1 acetic acid and 11% (v/v) ethanol) by 78% and 48%, respectively. Acetic acid removal by both strains was associated with a decrease in ethanol concentration of about 0.7 – 1.2% (v/v). Strain S26 revealed...

2010-01-01

4

Effects of acetic acid, ethanol, and SO2 on the removal of volatile acidity from acidic wines by two Saccharomyces cerevisiae commercial strains  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Herein, we report the influence of different combinations of initial concentration of acetic acid and ethanol on the removal of acetic acid from acidic wines by two commercial Saccharomyces cerevisiae strains S26 and S29. Both strains reduced the volatile acidity of an acidic wine (1.0 g l(-1) acetic acid and 11% (v/v) ethanol) by 78% and 48%, respectively. Acetic acid removal by strains S26 and S29 was associated with a decrease in ethanol concentration of 0.7 and 1.2% (v/v), respectively. S...

2010-01-01

5

AN EXPLORATORY STUDY ON THE REMOVAL OF ACETIC AND FORMIC ACIDS FROM BIO-OIL  

Directory of Open Access Journals (Sweden)

Full Text Available Bio-oil produced from fast pyrolysis of biomass contains various levels of acetic and formic acids derived from breakdown of cellulose and hemi-cellulose components. Removal of these organic acids from bio-oil was investigated for use as industrial chemicals as well as to improve the quality of recovered bio-oil as fuel in various applications. Calcium oxide and a quaternary ammonium anion-exchange resin were used to form acid salts of the organic acids, which were then separated, and the organic acids were generated by reacting with sulfuric acid. Both methods were found to be effective in limited ways and various difficulties encountered in this approach are discussed.

Badmakhand Sukhbaatar

6

Removal of Zn(II) from Aqueous Acetate Solution Using Di (2-Ethylhexyl) Phosphoric Acid & Tributylphosphate  

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The extraction of Zinc (II) in acetate medium with di (2-ethylhexyl) phosphoric acid (D2EHPA) in chloroform diluent was investigated under different experimental conditions, in order to have a better understanding of the extraction mechanism. The extraction yield was found to depend on the concentrations of Zinc (II) and D2EHPA, and the equilibrium pH. The effects of acetic acid and the salting-out agent were also studied. The nature of the extracted species was inv...

Brahim Guezzen; Mohamed Amine Didi

2012-01-01

7

Removal of Zn(II from Aqueous Acetate Solution Using Di (2-Ethylhexyl Phosphoric Acid & Tributylphosphate  

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Full Text Available The extraction of Zinc (II in acetate medium with di (2-ethylhexyl phosphoric acid (D2EHPA in chloroform diluent was investigated under different experimental conditions, in order to have a better understanding of the extraction mechanism. The extraction yield was found to depend on the concentrations of Zinc (II and D2EHPA, and the equilibrium pH. The effects of acetic acid and the salting-out agent were also studied. The nature of the extracted species was investigated by the slope analysis method. Graphs of log D vs. log [D2EHPA] and log D vs. pH were plotted for Zn (II, and the species extracted into the organic phase was found to have the composition (ZnCH3COOR.HR. The best performance was reached (80% with zinc concentrations lower than 5 mM in a neutral medium. The extraction yield of metals decreased as the acetic acid concentration increased with any given extractant concentration. The addition of sodium acetate to the aqueous phase strongly increased  the zinc extraction yield (99.5%. A synergistic effect was observed by the addition of tributhylphosphate (TBP with the organic phase.

Brahim Guezzen

2012-05-01

8

Selective oxidation of formic acid by ozone in acetic acid  

Energy Technology Data Exchange (ETDEWEB)

The authors lowered the temperature of acetic acid purification. Accordingly, the authors studied oxidation of formic acid by ozone in acetic acid in presence of a homogeneous catalyst (manganese acetate). Manganese acetate was added to a mixture of acetic and formic acid in a glass reactor of the bubbling type with a porous bottom. The experimental results are shown in a table. Study of selective oxidation of formic acid in acetic acid by ozone showed that with the use of a homogeneous catalyst (manganese acetate) formic acid can be removed from acetic at a considerably lower temperature than with the use of a heterogeneous catalyst (MnO/sub 2/).

Tarunin, B.I.; Aleksandrov, Y.A.; Perepletchikov, M.L.; Tarunina, V.N.

1985-09-01

9

Acetic acid vapor levels associated with facial prosthetics  

Energy Technology Data Exchange (ETDEWEB)

The use of Silastic Medical Adhesive Type A in the fabrication of facial prostheses may cause health hazards to the patient and the operator because of acetic acid emissions. Caution must be exercised to remove acetic acid vapors from the air and unliberated acetic acid from material applied directly to the skin.

McElroy, T.H.; Guerra, O.N.; Lee, S.A.

1985-01-01

10

ACETIC ACID AND A BUFFER  

DEFF Research Database (Denmark)

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

Bjarnsholt, Thomas Technical University of Denmark,

11

Molecular Structure of Acetic acid  

Science.gov (United States)

Acetic Acid commonly associated with vinegar; it is the most commercially important organic acid and is used to manufacture a wide range of chemical products, such as plastics and insecticides. Acetic acid is produced naturally by Aceto bacteria but, except for making vinegar, is usually made through synthetic processes. Ethanoic acid is used as herbicide, as a micro-biocide, as a fungicide and for pH adjustment.

2003-06-02

12

A novel fermentation strategy for removing the key inhibitor acetic acid and efficiently utilizing the mixed sugars from lignocellulosic hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

As part of preliminary research efforts, we have completed several experiments which demonstrate 'proof of concept.' These experiments addressed the following three questions: (1) Can a synthetic mixed sugar solution of glucose and xylose be efficiently consumed using the multi-organism approach? (2) Can this approach be used to accumulate a model product? (3) Can this approach be applied to the removal of an inhibitor, acetate, selectively from mixtures of xylose and glucose? To answer the question of whether this multi-organism approach can effectively consume synthetic mixed sugar solutions, we first tested substrate-selective uptake using two strains, one unable to consume glucose and one unable to consume xylose. The xylose-selective strain ALS998 has mutations in the three genes involved in glucose uptake, rendering it unable to consume glucose: ptsG codes for the Enzyme IICB{sup Glc} of the phosphotransferase system (PTS) for carbohydrate transport (Postma et al., 1993), manZ codes for the IID{sup Man} domain of the mannose PTS permease (Huber, 1996), glk codes for glucokinase (Curtis and Epstein 1975) We also constructed strain ALS1008 which has a knockout in the xylA gene encoding for xylose isomerase, rendering ALS1008 unable to consume xylose. Two batch experiments and one continuous bioprocess were completed. In the first experiment, each strain was grown separately in a defined medium of 8 g/L xylose and 15 g/L glucose which represented xylose and glucose concentrations that can be generated by actual biomass. In the second experiment, the two strains were grown together in batch in the same defined, mixed-sugar medium. In a third experiment, we grew the strains continuously in a 'chemostat', except that we shifted the concentrations of glucose and xylose periodically to observe how the system would respond. (For example, we shifted the glucose concentration suddenly from 15 g/L to 30 g/L in the feed).

Mark A. Eiteman PHD; Elliot Altman Phd

2009-02-11

13

Influence of acetic acid on water structure  

International Nuclear Information System (INIS)

Full text: By methods of structural temperature, viscous flow activation entropye and partial molal volume(V) the influence of acetic acid on water structure has been considered. It revealed that the acetic acid destroyes the water structure

2011-06-01

14

Maleopimaric acid acetic acid solvate  

Directory of Open Access Journals (Sweden)

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

Meng Zhang

2009-07-01

15

5. System of acetic acid-ethanethiol  

International Nuclear Information System (INIS)

Low-temperature gamma-radiolysis of the acetic acid-ethanethiol system is investigated in a wide range of ratios of initial components. EPR spectra of paramagnetic particles which appear both from acetic acid and ethanethiol are shown to form during radiolysis of ethanethiol solid solution in the acetic acid. The estimation of energy transfer probability (?) shows that the maximum value of energy transfer probability in the acetic acid-ethanethiol system is ?=0.59 with Esub(T)0.4. The thiol effective protection of acetic acid from high energy radiations is shown

1979-01-01

16

Kinetics of acetic acid esterification over ion exchange catalysts  

Energy Technology Data Exchange (ETDEWEB)

Computer simulation showed that catalytic distillation was an attractive process for the removal of dilute acetic acid from wastewater. Kinetic measurements were conducted in a batch reactor. Methanol was added to the dilute acetic acid solutions and reacted with the acid in water to form methyl acetate and water. The reaction could be catalyzed by solid acid catalysts. Amberlyst 15 was found to be an effective catalyst for this reaction. The effects of stirrer speed, reaction temperature, reactant concentration and catalyst loading on the reaction rate were investigated, and it was found that external resistance to the reaction process could easily be eliminated. The kinetic equation developed could be used in the design of the catalytic distillation column to remove low concentration of acetic acid from wastewater. 20 refs., 9 figs., 1 tab.

Xu, Z.P.; Chuang, K.T. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical Engineering

1996-08-01

17

Acetic Acid Production by an Electrodialysis Fermentation Method with a Computerized Control System  

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In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth an...

Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

1988-01-01

18

Electron transfer induced fragmentation of acetic acid  

Science.gov (United States)

We present negative ion formation driven by electron transfer in atom (K) molecule (acetic acid) collisions. Acetic acid has been found in the interstellar medium, is also considered a biological related compound and as such studying low energy electron interactions will bring new insights as far as induced chemistry is concerned.

Ferreira da Silva, F.; Meneses, G.; Almeida, D.; Limão-Vieira, P.

2014-04-01

19

Correlation between acetic acid resistance and characteristics of PQQ-dependent ADH in acetic acid bacteria.  

Science.gov (United States)

In this study, we compared the growth properties and molecular characteristics of pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) among highly acetic acid-resistant strains of acetic acid bacteria. Gluconacetobacter europaeus exhibited the highest resistance to acetic acid (10%), whereas Gluconacetobacter intermedius and Acetobacter pasteurianus resisted up to 6% of acetic acid. In media with different concentrations of acetic acid, the maximal acetic acid production rate of Ga. europaeus slowly increased, but specific growth rates decreased concomitant with increased concentration of acetic acid in medium. The lag phase of A. pasteurianus was twice and four times longer in comparison to the lag phases of Ga. europaeus and Ga. intermedius, respectively. PQQ-dependent ADH activity was twice as high in Ga. europaeus and Ga. intermedius as in A. pasteurinus. The purified enzymes showed almost the same specific activity to each other, but in the presence of acetic acid, the enzyme activity decreased faster in A. pasteurianus and Ga. intermedius than in Ga. europaeus. These results suggest that high ADH activity in the Ga. europaeus cells and high acetic acid stability of the purified enzyme represent two of the unique features that enable this species to grow and stay metabolically active at extremely high concentrations of acetic acid. PMID:16133326

Trcek, Janja; Toyama, Hirohide; Czuba, Jerzy; Misiewicz, Anna; Matsushita, Kazunobu

2006-04-01

20

Acetic acid mediated interactions between alumina surfaces  

International Nuclear Information System (INIS)

Low-molecular-weight organic acids have been known to modify colloidal stability of alumina-based suspensions. We investigated interaction forces between alumina surfaces mediated by acetic acid which is one of the simplest organic acids. Forces between alumina surfaces were measured using the colloid-probe method of atomic force microscope (AFM). Repulsive forces attributed to steric repulsion due to adsorbed molecules and electrostatic repulsion dominated the interaction. Results of rheological characterization of the alumina slurry containing acetic acid supported the finding.

2012-02-01

 
 
 
 
21

Isolation of acetic acid bacteria from honey  

Directory of Open Access Journals (Sweden)

Full Text Available Four thermotolerant acetic acid bacteria designated as CMU1, CMU2, CMU3 and CMU4 were isolated from six honey samples produced by three native bee species in northern Thailand, namely the dwarf honey bee (Apis florea, Asian honey bee (A. cerena and giant honey bee (A. dorsata. All isolates were tested for their tolerance to acetic acid and ethanol at 30?C and 37?C. It was found that they grew only in a medium containing 1% (v/v acetic acid at 30?C. However, isolate CMU4 showed the highest toleration to ethanol, viz. 10% (v/v and 9% (v/v at 30?C and 37?C respectively. Morphological and biochemical examination indicated that all isolates were members of the genus Gluconobacter.

Wasu Pathom-aree

2009-02-01

22

4,4?-Bipyridine acetic acid disolvate  

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Full Text Available The crystal structure of the title compound, C10H8N2·2C2H4O2, is built up from 4,4?-bipyridine and acetic acid molecules linked by strong O—H...N hydrogen bonds. The 4,4?-bipyridine and the two acetic acid molecules are further connected through weak C—H...O hydrogen bonds to form a supramolecular two-dimensional network parallel to the (001 plane. The two pyridine rings make a dihedral angle of 31.8?(1°.

Ling Ye

2008-01-01

23

Boric acid removing device  

International Nuclear Information System (INIS)

In a PWR type reactor, crystals of boric acids are often deposited to a gap between a pipe stand and a thermal sleeve. In the present invention, warm water or steam is blown from a nozzle to the crystals of boric acid deposited to the gap to remove them by melting boric acid within an aimed range of non-destructive testing. Then, air is blown to the gap to keep it dry. Boric acid within the aimed range of non-destructive testing can be reliably removed easily within a short period of time by thus blowing warm water or steam at a predetermined temperature from the nozzle toward the gap. Then, since air is blown to keep the dried state, the boric acid is not recrystallized. As a result, the operation efficiency of the non-destructive testing is improved, as well as the accuracy of detection data can be maintained. (N.H.)

1992-12-24

24

Labelling indole-3-acetic acid with tritium  

International Nuclear Information System (INIS)

A simple method for obtaining indole-3-acetic acid (growth stimulating plant hormone C_1_0H_9NO_2) labelled with tritium is described. The preparate has specific radioactivity of 455 MBq/mmol, and 50% yield as compared to the initial amount of used substance. (author)

1986-05-31

25

Separating acetic acid from furol (furfural) by electrodialysis method  

Energy Technology Data Exchange (ETDEWEB)

Furfural production by hydrolysis of fibrous plant materials is accompanied by formation of acetic acid in amounts depending on the material used. The amount of acetic formed in the hydrolysis of the fruit shell of oil-tea camellia (Camellia oleosa) (an oilseed-bearing tree) is equal to the amount of furfural. The acetic acid can be separated from the furfural and concentrated to 10% by electrodialysis. A smaller amount of furfural is separated with acetic acid.

Guan, S.F.; Li, C.S. Ye, S.T.; Shen, S.Y.; Wang, Y.T.; Yu, S.H.

1981-01-01

26

Ultrasonic etching in polymethyl-methacrylate using chlorinated acetic acids  

Energy Technology Data Exchange (ETDEWEB)

The etching of irradiated polymethyl-methacrylate films was studied by an ultrasonic technique using a new etching agent -chlorinated acetic acid solution. The hole density increased with increasing number of chlorine atoms in the chlorinated acetic acid molecule. Trichloro acetic acid was the most effective etching agent. Hole diameter and density were affected by etching conditions such as the concentration of trichloro acetic acid solution, etching time and etching temperature. Holes with a diameter from 0.2 to 0.5 [mu]m were formed by ultrasonic etching using 25% trichloro acetic acid solution for 6 h at 20[sup o]C. (author).

Kumakura, M. (The Nishi-Tokyo Univ., Yamanashi (Japan). Dept. of Bioscience); Yoshida, M. (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment); Komaki, Y.; Ishikawa, J.; Sakurai, T.; Furukawa, K.; Ohno, S. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment)

1993-04-01

27

Recovery of very dilute acetic acid using ion exchange  

Energy Technology Data Exchange (ETDEWEB)

Acetic and related acids occur in many industrial wastewaters, often mixed with several other classes of organic compounds. Acetic acid can be recovered from 1% solutions using weakly basic ion exchange resins. The acid is adsorbed by the free-base form of the resin, which can then be eluted using a slurry of lime to give a solution of calcium acetate. This solution could either be evaporated to crystallize calcium acetate or reacted with sulfuric acid to form acetic acid and gypsum. Laboratory tests of the proposed process gave product solutions of 15--20% acetic acid using pure 1% acetic acid as feed. Some measurements using a typical industrial effluent gave similar recoveries and showed that there was no initial fouling of the resins.

Cloete, F.L.D.; Marais, A.P. [Univ. of Stellenbosch (South Africa). Dept. of Chemical Engineering

1995-07-01

28

Complexing of hafnium tetrafluoride in acetic acid  

International Nuclear Information System (INIS)

The process of hafnium tetrafluoride complexing with potassium fluoride in the media of waterless acetic acid, is investigated. Concentration regions of the potassium fluorohafnates formation are established. The methods of chemical and X-ray diffraction analyses have been used to study the separated KHfF"5xCH"3COOH, k"2HfF"6. Investigation of thermal stability of the KHfF"5xCH"3COOH solvate shows, that CH"3COOH molecule splitting off takes place at 108 deg

1982-05-01

29

Submillimeter wave spectrum of acetic acid  

Science.gov (United States)

We present a new global study of the submillimeter wave spectrum of the lowest three torsional states of acetic acid (CH3COOH). New measurements involving torsion-rotation transitions with J up to 79 and Ka up to 44 have been carried out between 230 and 845 GHz using the submillimeter wave spectrometers in University of Cologne and Jet Propulsion Laboratory. The new data were combined with previously published measurements and fitted using the rho-axis-method torsion-rotation Hamiltonian. The final fit used 93 parameters to give an overall weighted root-mean-square deviation of 0.85 for a dataset consisting of 7543, 6087, and 5171 transitions belonging, respectively, to the ground, first, and second excited torsional states and 1888 ?vt ? 0 transitions. This investigation presents more than a twofold expansion both in the J quantum number and frequency range coverage of the acetic acid spectrum. Numerous inter-torsional interactions have been observed. Furthermore, this is the highest J value ever treated with the rho-axis-method and provides a good test case for the theoretical model in use.

Ilyushin, Vadim V.; Endres, Christian P.; Lewen, Frank; Schlemmer, Stephan; Drouin, Brian J.

2013-08-01

30

Reactions of the radical cations of acetic acid and acetic anhydride in CFClsub(3). [Gamma radiation  

Energy Technology Data Exchange (ETDEWEB)

The ESR spectra of el-irradiated solutions of acetic acid and acetic anhydride were studied depending on their concentrations in CFClsub(3). The structure of thus produced radical cations is confirmed with the deuterium substituted analogues. It is shown that the ion-molecular reaction of the radical cation CHsub(3) COOHsup(+) in the isolated dimer takes place for the dilute solutions of acetic acid in CFClsub(3) resulting in the formation of CHsub(3)COO followed by its decomposition to CHsub(3) + COsub(2) while the radicals CHsub(2)COOH are formed via secondary processes. The reactions of radical cations of acetic oxide were also studied.

Belevskij, V.N.; Belopushkin, S.I.; Feldman, V.I.

1985-11-01

31

Reactions of the radical cations of acetic acid and acetic anhydride in CFClsub(3)  

International Nuclear Information System (INIS)

The ESR spectra of ?-irradiated solutions of acetic acid and acetic anhydride were studied depending on their concentrations in CFClsub(3). The structure of thus produced radical cations is confirmed with the deuterium substituted analogues. It is shown that the ion-molecular reaction of the radical cation CHsub(3) COOHsup(+) in the isolated dimer takes place for the dilute solutions of acetic acid in CFClsub(3) resulting in the formation of CHsub(3)COO followed by its decomposition to CHsub(3) + COsub(2) while the radicals CHsub(2)COOH are formed via secondary processes. The reactions of radical cations of acetic oxide were also studied. (author)

1985-11-01

32

Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays  

Science.gov (United States)

Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

Reinecke, D. M.; Bandurski, R. S.

1988-01-01

33

Methane-to-acetic acid synthesis matriculates at Penn State  

Energy Technology Data Exchange (ETDEWEB)

Direct conversion of methane to commercially valuable chemicals remains one of the grails of industrial chemistry. But scientists at Pennsylvania State University (University Park) appear to have made a significant step forward, reporting the direct catalytic conversion of methane into acetic acid under relatively mild conditions. Commercial acetic production involves a three-step process, including steam reforming of methane to synthesis gas (syngas) and the carbonylation of methanol of acetic acid.

Rotman, D.

1994-04-20

34

Micelles Protect and Concentrate Activated Acetic Acid  

Science.gov (United States)

As more and more exoplanets are discovered and the habitability of such planets is considered, one can turn to searching for the origin of life on Earth in order to better understand what makes a habitable planet. Activated acetic acid, or methyl thioacetate, has been proposed to be central to the origin of life on Earth, and also as an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about three orders of magnitude faster (K = 0.00663 s^-1; 100°C, pH 7.5, concentration = 0.33mM) than published rates for its catalyzed production making it unlikely to accumulate under prebiotic conditions. However, we also observed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. We found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid micelles. Thus, the hydrophobic regions of prebiotic micelles and early cell membranes could have offered a refuge for this energetic molecule increasing its lifetime in close proximity to the reactions for which it would be needed. Methyl thioacetate could thus be important for the origin of life on Earth and perhaps for better understanding the potential habitability of other planets.

Todd, Zoe; House, C.

2014-01-01

35

Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings  

Science.gov (United States)

Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

1986-01-01

36

Adsorption of acetic acid on different carbons  

Directory of Open Access Journals (Sweden)

Full Text Available This study presents a double environmental aspect, on one hand, decline of the cost of the waste water treatment thanks to a cheap adsorbing, on the other hand, the valuation of coconut shells.The acetic acid was used as adsorbent because the knowledge of the size of its molecule (21 Å2 allows characterizing studied carbons.The model of Langmuir describes well the isotherms of adsorption on the various types of studied carbons. It stands out in this study that the capacity of adsorption of inactivated carbon grain (CNAG COCO doubles practically if this one is reduced in powder. Besides, the inactivated carbon powder (CNAP COCO and the activated carbon grain (CAG COCO have the same capacity of adsorption. So, the specific surfaces of the CNAP COCO and CAG COCO are identical: SL = 77 m2/g while that of the CNAG is only 32 m2/g. The use of inactivated carbon powder can be thus recommended to treat waste water opposite the inactivated grain carbon which isn’t of real interest.

K. Ouattara

2012-10-01

37

Oxidation of indole-3-acetic acid and oxindole-3-acetic acid to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glucopyranoside in Zea mays seedlings  

Science.gov (United States)

Radiolabeled oxindole-3-acetic acid was metabolized by roots, shoots, and caryopses of dark grown Zea mays seedlings to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glycopyranoside with the simpler name of 7-hydroxyoxindole-3-acetic acid-glucoside. This compound was also formed from labeled indole-3-acetic acid supplied to intact seedlings and root segments. The glucoside of 7-hydroxyoxindole-3-acetic acid was also isolated as an endogenous compound in the caryopses and shoots of 4-day-old seedlings. It accumulates to a level of 4.8 nanomoles per plant in the kernel, more than 10 times the amount of oxindole-3-acetic acid. In the shoot it is present at levels comparable to that of oxindole-3-acetic acid and indole-3-acetic acid (62 picomoles per shoot). We conclude that 7-hydroxyoxindole-3-acetic acid-glucoside is a natural metabolite of indole-3-acetic acid in Z. mays seedlings. From the data presented in this paper and in previous work, we propose the following route as the principal catabolic pathway for indole-3-acetic acid in Zea seedlings: Indole-3-acetic acid --> Oxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid-glucoside.

Nonhebel, H. M.; Bandurski, R. S.

1984-01-01

38

Enrichment of amino acid-oxidizing, acetate-reducing bacteria.  

Science.gov (United States)

In anaerobic condition, amino acids are oxidatively deaminated, and decarboxylated, resulting in the production of volatile fatty acids. In this process, excess electrons are produced and their consumption is necessary for the accomplishment of amino acid degradation. In this study, we anaerobically constructed leucine-degrading enrichment cultures from three different environmental samples (compost, excess sludge, and rice field soil) in order to investigate the diversity of electron-consuming reaction coupled to amino acid oxidation. Constructed enrichment cultures oxidized leucine to isovalerate and their activities were strongly dependent on acetate. Analysis of volatile fatty acids (VFAs) profiles and community structure analysis during batch culture of each enrichment indicated that Clostridium cluster I coupled leucine oxidation to acetate reduction in the enrichment from the compost and the rice field soil. In these cases, acetate was reduced to butyrate. On the other hand, Clostridium cluster XIVb coupled leucine oxidation to acetate reduction in the enrichment from the excess sludge. In this case, acetate was reduced to propionate. To our surprise, the enrichment from rice field soil oxidized leucine even in the absence of acetate and produced butyrate. The enrichment would couple leucine oxidation to reductive butyrate synthesis from CO2. The coupling reaction would be achieved based on trophic link between hydrogenotrophic acetogenic bacteria and acetate-reducing bacteria by sequential reduction of CO2 and acetate. Our study suggests anaerobic degradation of amino acids is achieved yet-to-be described reactions. PMID:24630616

Ato, Makoto; Ishii, Masaharu; Igarashi, Yasuo

2014-08-01

39

Simultaneous introduction of nitric, acetic and trifluoroacetic acids into anthracite  

Energy Technology Data Exchange (ETDEWEB)

Absorption tests are discussed made using Donetsk anthracite and acetic, trifluoroacetic and nitric acids. Results obtained indicate that reaction is exothermic and that nitric acid vapor increases absorption of carboxylic acid. A similar effect is shown by potassium nitrate deposited on anthracite. Much faster oxidestruction takes place in a mixture of nitric acid and helium. AcOH molecules exert a stabilizing effect, stop reaction at chemisorption stage and prevent oxidestruction. Effect is analyzed of nitric and acetic acids on oxidestruction and it is concluded that at 130 C initial absorption rate of nitric acid is approximately 40 times that of acetic acid. Anthracite in a mixture of nitric and acetic acids absorbs nitric acid first and thus facilitates absorption of carboxylic acid at later stages. Synergism occurs on absorption of mixture of nitric and acetic acids. Presence of nitric acid increases sorption of carboxylic acid which in turn stabilizes sorbent and promotes further absorption of nitric acid, thus considerably increasing sorption capacity of anthracite. 4 refs.

Rudakov, E.S.; Sapunov, V.A.; Metlova, L.P.; Kucherenko, V.A.; Zverev, I.V.

1986-11-01

40

Kinetic study of acetic acid exchange on manganese(II), cobalt(II), and copper(II) acetates in acetic acid by oxygen-17 nuclear magnetic resonance  

Energy Technology Data Exchange (ETDEWEB)

The authors have previously studied acetic acid exchange on perchlorates of manganese(II), iron(II), cobalt(II), nickel(II), and copper(II) ions in acetic acid (HOAc). These metal(II) perchlorates in acetic acid exist as hexasolventometal ions that form ion pairs with perchlorate anion. On the other hand, acetate ion (OAc/sup -/) in transition-metal(II) acetates is bound to the central metal ions in acetic acid. Thus, they expect that coordinated acetate ion exerts some effect on the solvent-exchange rate, i.e., bound-ligand effect. In this work rates of acetic acid exchange on Mn(OAc)/sub 2/, Co(OAc)/sub 2/, and Cu/sub 2/(OAc)/sub 4/ (tetrakis(..mu..-acetato)dicopper(II)) in acetic acid and mixtures with dichloromethane-d/sub 2/ as an inert cosolvent were measured by means of the oxygen-17 NMR line-broadening method. The activation parameters obtained are compared with those for the corresponding perchlorates.

Hioki, A.; Funahashi, S.; Tanaka, M.

1986-07-30

 
 
 
 
41

Thermal decomposition of sodium perborate in acetic and trifluoroacetic acids  

International Nuclear Information System (INIS)

Study of sodium perborate thermal decomposition kinetics in acetic and trifluoroacetic acids permitted ascertaining the decomposition rate constants for two groups of compounds with different types of peroxide bonds. It has been revealed that sodium perborate decomposition in trifluoroacetic acid occurs according to the first order. Sodium perborate decomposition in acetic acid is complicated by formation of two types of compounds featuring different mechanisms of decomposition

1999-10-01

42

Plasmacatalytic removal of lead acetate assisted by precipitation.  

Science.gov (United States)

The Gliding Arc Discharge (GAD) is an efficient non-thermal plasma technique able to degrade organic compounds dispersed in water at atmospheric pressure. The degradation of the organometallic lead acetate (PbAc) in aqueous solution was performed by two distinct plasmageneous processes: GAD and GAD/TiO2. The global oxidation of the organic matter was followed by Chemical Oxygen Demand (COD) and the mineralization was determined by the Total Organic Carbon (TOC). The Pb(2+) ions released during the degradation process were measured by Atomic Absorption Spectroscopy (AAS). For 2h of GAD treatment, the degradation rate of PbAc (10mM) reached 83% and for the same duration of GAD/TiO2 process ([TiO2]=1gL(-1)), it reached 93%. The release of Pb(2+) ions in the solution was respectively of 95% and 57% for GAD and GAD/TiO2 processes. The released Pb(2+) ions were removed by precipitation process in a basic medium at pH=11.1. A reaction mechanism was proposed to explain the PbAc molecule degradation and the Pb(2+) elimination. PMID:24462087

Haddou, Nabila; Ghezzar, Mouffok Redouane; Abdelmalek, Fatiha; Ognier, Stéphanie; Martel, Marc; Addou, Ahmed

2014-07-01

43

40 CFR 180.1258 - Acetic acid; exemption from the requirement of a tolerance.  

Science.gov (United States)

...2009-07-01 2009-07-01 false Acetic acid; exemption from the requirement...From Tolerances § 180.1258 Acetic acid; exemption from the requirement...residues of the biochemical pesticide acetic acid when used as a...

2009-07-01

44

21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.  

Science.gov (United States)

...2009-04-01 false 5-Hydroxyindole acetic acid/serotonin test system. 862...862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a...Identification. A 5-hydroxyindole acetic acid/serotonin test system is a...

2009-04-01

45

21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.  

Science.gov (United States)

...2009-04-01 false 5-Hydroxyindole acetic acid/serotonin test system. 862...Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A 5-hydroxyindole acetic acid/serotonin test system is a...

2009-04-01

46

Biosynthetic origin of acetic acid using SNIF-NMR  

International Nuclear Information System (INIS)

The main purpose of this work is to describe the use of the technique Site-Specific Natural Isotopic Fractionation of hydrogen (SNIF-NMR), using 2H and 1H NMR spectroscopy, to investigate the biosynthetic origin of acetic acid in commercial samples of Brazilian vinegar. This method is based on the deuterium to hydrogen ratio at a specific position (methyl group) of acetic acid obtained by fermentation, through different biosynthetic mechanisms, which result in different isotopic ratios. We measured the isotopic ratio of vinegars obtained through C3, C4, and CAM biosynthetic mechanisms, blends of C3 and C4 (agrins) and synthetic acetic acid. (author)

2006-01-01

47

The antibacterial activity and stability of acetic acid.  

Science.gov (United States)

Acetic acid has been shown to have good antibacterial activity against micro-organisms such as Pseudomonas aeruginosa. This study examined the activity against a range of bacterial pathogens and also assessed any reduction in antibacterial activity due to evaporation or inactivation by organic material in dressings. Acetic acid was active at dilutions as low as 0.166% and the activity was not reduced by evaporation nor by inactivation by cotton swabs. Burn injuries are a major problem in countries with limited resources. Acetic acid is an ideal candidate for use in patients who are treated in those parts of the world. PMID:23747099

Fraise, A P; Wilkinson, M A C; Bradley, C R; Oppenheim, B; Moiemen, N

2013-08-01

48

Radiolysis of the acetic acid-ethane thiol binary system  

International Nuclear Information System (INIS)

The method of electronic paramagnetic resonance has been applied to study the low temperature radiolysis of the binary acetic acidethanethiol system with a different correlation of components. EPR spectra of paramagnetic centers which appear from both acetic acid and ethanethiol are observed in the radiolysis of ethanethiol solid solutions in the acetic acid of sufficient concentration (6-10 M solutions). Radiation chemical outputs of the process are determined. The conclusion is made that low ethanethiol concentrations defend the molecules of the acid. The possibility of introducing the directed radiolysis of a number of binary systems is noted

1980-01-01

49

Production of acetic acid, propionic acid and their esters  

International Nuclear Information System (INIS)

When carbon monoxide and hydrogen (syngas) are reacted at elevated temperature and pressure (above 150 degrees Celsius, above 35 bars) in the presence of a ruthenium-containing catalyst and a cobalt, titanium or zirconium co-catalyst dispersed in a low-melting quaternary ammonium or phosphonium compound, the reaction is directed to the selective production of carboxylic acids (acetic, propionic) and their esters by employing a halogen-containing cobalt, titanium or zirconium compound as co-catalyst or by employing a halogen free cobalt, titanium or zirconium compound in the presence of iodine or an iodine compound

1982-01-01

50

Correlation of vapor - liquid equilibrium data for acetic acid - isopropanol - water - isopropyl acetate mixtures  

Directory of Open Access Journals (Sweden)

Full Text Available A correlation procedure for the prediction of vapor - liquid equilibrium of acetic acid - isopropanol - water - isopropyl acetate mixtures has been developed. It is based on the NRTL model for predicting liquid activity coefficients, and on the Hayden-O'Connell second virial coefficients for predicting the vapor phase of systems containing association components. When compared with experimental data the correlation shows a good agreement for binary and ternary data. The correlation also shows good prediction for reactive quaternary data.

B. A. Mandagarán

2006-03-01

51

Correlation of vapor - liquid equilibrium data for acetic acid - isopropanol - water - isopropyl acetate mixtures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A correlation procedure for the prediction of vapor - liquid equilibrium of acetic acid - isopropanol - water - isopropyl acetate mixtures has been developed. It is based on the NRTL model for predicting liquid activity coefficients, and on the Hayden-O'Connell second virial coefficients for predicting the vapor phase of systems containing association components. When compared with experimental data the correlation shows a good agreement for binary and ternary data. The correlation also shows...

2006-01-01

52

Acetic acid oxidation and hydrolysis in supercritical water  

Energy Technology Data Exchange (ETDEWEB)

Acetic acid (CH{sub 3}COOH) hydrolysis and oxidation in supercritical water were examined from 425--600 C and 246 bar at reactor residence times of 4.4 to 9.8 s. Over the range of conditions studied, acetic acid oxidation was globally 0.72 {+-} 0.15 order in acetic acid and 0.27 {+-} 0.15 order in oxygen to a 95% confidence level, with an activation energy of 168 {+-} 21 kJ/mol, a preexponential factor of 10{sup 9.9{+-}1.7}, and an induction time of about 1.5 s at 525 C. Isothermal kinetic measurements at 550 C over the range 160 to 263 bar indicated that pressure or density did not affect the rate of acetic acid oxidation as much as was previously observed in the oxidation of hydrogen or carbon monoxide in supercritical water. Major products of acetic acid oxidation in supercritical water are carbon dioxide, carbon monoxide, methane, and hydrogen. Trace amounts of propenoic acid were occasionally detected. Hydrolysis or hydrothermolysis in the absence of oxygen resulted in approximately 35% conversion of acetic acid at 600 C, 246 bar, and 8-s reactor residence time. Regression of the limited hydrolysis runs assuming a reaction rate first-order in organic gave a global rate expression with a preexponential factor of 10{sup 4.4{+-}1.1} and an activation energy of 94 {+-} 17 kJ/mol.

Meyer, J.C.; Marrone, P.A.; Tester, J.W. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1995-09-01

53

Recovery of Acetic Acid From Effluent via Freeze Crystallization  

Directory of Open Access Journals (Sweden)

Full Text Available Freeze crystallization is an efficient separation process that can potentially be used in any application. Freeze crystallization is a high energy efficiency separation process that can be applied to a wide variety of industrial requirements. Although the vapor-liquid equilibrium is generally employed to separate the components of a solution, use of solid-liquid equilibrium should be considered – it may be cheaper. This paper describes a case study of recovery of acetic acid from effluent via freeze crystallization. Complete recovery of acetic acid from acetic acid-water solution by ordinary distillation is nearly impossible, because relative volatility of this mixture in the range of 1-30% of acetic acid in water is very close to one. But the same separation is possible by freeze separation technique and it is found experimentally that large amount of acetic acid (about 71.5% can be recovered via freeze separation technique. Also it is found that the energy required for recovery of acetic acid is much lower (about 24 times than that of distillation.

Tarak C. Padhiyar

2013-04-01

54

Ternary Phase Equilibrium Data for Acetic Acid-Water-Solvent Systems and Separation of Acetic Acid from Aqueous Solution  

Directory of Open Access Journals (Sweden)

Full Text Available Ternary phase equilibrium data for acetic acid with water and solvent (n-butyl alcohol, isobutyl alcohol and amyl alcohol are presented and used to evaluate the possibility of employing distribution of acetic acid between water and these alcohols as a means of separation of acetic acid from its aqueous solution. Mutual solubility curves, tie-line data, distribution coefficient, selectivity diagrams and separation factor data were determined for these systems. From these data it has been concluded that of these solvents amyl alcohol offers the best hope of achieving separation of acetic acid by distribution between amyl alcohol and water as it has the highest separation factor value than those of other two alcohols.

Bhupesh C. Roy

2005-01-01

55

Investigation of hafnium acetate complexing with potassium fluoride in anhydrous acetic acid  

International Nuclear Information System (INIS)

Using hafnium tetraacetate as initial component an attempt is made to clarify the effect of anion on the complexing and possibility of tetraacetate solvation procedure in the medium of non-aqueous solvents. Hafnium tetraacetate and acetic acid form solvate complexes Hf(CH"3COO)"4 x 7CH"3COOH and Hf(CH"3COO)"4 x 10CH"3COOH at the expense of donor - acceptor interaction. Hafnium tetraacetate and potassium fluoride in anhydrous acetic acid form the complexes KF x Hf(CH"3COO)"4 and KF x Hf(CH"3COO)"4 x 5CH"3COOH

1982-11-01

56

Tetrazole acetic acid: Tautomers, conformers, and isomerization  

Science.gov (United States)

Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0-8 kJ mol-1 energy range and should be appreciably populated at the sublimation temperature (˜330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol-1) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol-1). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm-1, where the first OH stretching overtone vibrations of 1ccc and 2pcc occur. The reverse transformations could be induced by irradiations at 7010 and 7030 cm-1, transforming 1cct and 2pct back to 1ccc and 2pcc, also selectively. Besides the NIR-induced transformations, the photogenerated 1cct and 2pct forms also decay in N2 matrices back to 1ccc and 2pcc spontaneously, with characteristic decay times of hours (1H) and tens of minutes (2H). The decay mechanism is rationalized in terms of the proton tunneling. In crystals, TAA exists exclusively as 1H-tautomer. By contrast, the tautomeric composition of the matrix-isolated monomers was found to consist of both 1H- and 2H-tautomers, in comparable amounts. A mechanistic discussion of the tautomerization process occurring during sublimation, accounting also for the observed minor decomposition of TAA leading to CO2 and 5-methyl-tetrazole, is proposed.

Araujo-Andrade, C.; Reva, I.; Fausto, R.

2014-02-01

57

Tetrazole acetic acid: tautomers, conformers, and isomerization.  

Science.gov (United States)

Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0-8 kJ mol(-1) energy range and should be appreciably populated at the sublimation temperature (?330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol(-1)) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol(-1)). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm(-1), where the first OH stretching overtone vibrations of 1ccc and 2pcc occur. The reverse transformations could be induced by irradiations at 7010 and 7030 cm(-1), transforming 1cct and 2pct back to 1ccc and 2pcc, also selectively. Besides the NIR-induced transformations, the photogenerated 1cct and 2pct forms also decay in N2 matrices back to 1ccc and 2pcc spontaneously, with characteristic decay times of hours (1H) and tens of minutes (2H). The decay mechanism is rationalized in terms of the proton tunneling. In crystals, TAA exists exclusively as 1H-tautomer. By contrast, the tautomeric composition of the matrix-isolated monomers was found to consist of both 1H- and 2H-tautomers, in comparable amounts. A mechanistic discussion of the tautomerization process occurring during sublimation, accounting also for the observed minor decomposition of TAA leading to CO2 and 5-methyl-tetrazole, is proposed. PMID:24527914

Araujo-Andrade, C; Reva, I; Fausto, R

2014-02-14

58

CO2 Corrosion Mechanism of Carbon Steel in the Presence of Acetate and Acetic Acid  

International Nuclear Information System (INIS)

The corrosion behavior of carbon steel (N80) in carbon dioxide saturated 1%NaCl solution with and without acetic acid or acetate was investigated by weight-loss test, electrochemical methods (polarization curve, Electrochemical impedance spectroscopy). The major objective is to make clear that the effect of acetic acid and acetate on the corrosion of carbon steel in CO2 environments. The results indicate that either acetic acid or acetate accelerates cathodic reducing reaction, facilitates dissolution of corrosion products on carbon steel, and so promotes the corrosion rate of carbon steel in carbon dioxide saturated NaCl solution. All Nyquist Plots are consisting of a capacitive loop in high frequency region, an inductive loop in medial frequency region and a capacitive arc in low frequency region. The high frequency capacitive loop, medial frequency inductive loop and low frequency capacitive arc are corresponding to the electron transfer reaction, the formation/adsorption of intermediates and dissolution of corrosion products respectively. All arc of the measured impedance reduced with the increase of the concentration of Ac-, especially HAc. However, the same phenomenon is not notable after reducing pH value by adding HCI. HAc is a stronger proton donor and can be reduced directly by electrochemical reaction firstly. Ac- can't participate in electrochemistry reaction directly, but Ac- an hydrate easily to create HAc in carbon dioxide saturated environments. HAc is as catalyst in CO2 corrosion. As a result, the corrosion rate was accelerated in the presence of acetate ion even pH value of solution increased

2007-10-01

59

Synthesis of imidazol-1-yl-acetic acid hydrochloride: A key intermediate for zoledronic acid  

Directory of Open Access Journals (Sweden)

Full Text Available A convenient and practical synthesis of imidazol-1-yl-acetic acid hydrochloride was achieved via N-alkylation of imidazole using tert-butyl chloroacetate followed by a non-aqueous ester cleavage of the resulting imidazol-1-yl-acetic acid tert-butyl ester in the presence of titanium tetrachloride. The synthesized imidazol-1-yl-acetic acid hydrochloride was then utilized to prepare zoledronic acid.

2008-11-01

60

Additive effects of acetic acid upon hydrothermal reaction of amylopectin  

International Nuclear Information System (INIS)

It is well known that over 0.8 kg kg?1 of starch is consisted of amylopectin (AP). In this study, production of glucose for raw material of ethanol by hydrothermal reaction of AP as one of the model compound of food is discussed. Further, additive effects of acetic acid upon hydrothermal reactions of AP are also investigated. During hydrothermal reaction of AP, production of glucose occurred above 453 K, and the glucose yield increased to 0.48 kg kg?1 at 473 K. Upon hydrothermal reaction of AP at 473 K, prolongation of the holding time was not effective for the increase of the glucose yield. Upon hydrothermal reaction of AP at 473 K for 0 s, the glucose yield increased significantly by addition between 0.26 mol L?1 and 0.52 mol L?1 of acetic acid. However, the glucose yield decreased and the yield of the other constituents increased with the increases of concentration of acetic acid from 0.65 mol L?1 to 3.33 mol L?1. It was considered that hydrolysis of AP to yield glucose was enhanced due to the increase of the amount of proton derived from acetic acid during hydrothermal reaction with 0.52 mol L?1 of acetic acid. -- Highlights: ? Glucose production by hydrothermal reaction of amylopectin (AP) at 473 K. ? Glucose yield increased to 0.48 kg kg-1 at 473 K. ? Prolongation of holding time was not effective for glucose yield. ? Glucose yield increased significantly by acetic acid (0.26–0.52 mol L-1) addition. ? Hydrolysis of AP to glucose was enhanced due to increase of proton from acetic acid.

2012-09-01

 
 
 
 
61

Rates and mechanism of the reactions of hydroxyl radicals with acetic, deuterated acetic, and propionic acids in the gas phase  

International Nuclear Information System (INIS)

Rate constants for the reactions of hydroxyl radicals with the monomer and dimer of acetic acid, deuterated acetic acids, and propionic acid have been determined by a laser photolysis-resonance absorption technique. Hydroxyl radicals were generated by photolysis of the acids at 222 nm with a KrCl laser and their decay was followed by time-resolved resonance absorption. The monomers of acetic and deuterated acetic acids reacted with OH much faster than the dimers, whereas the monomer and dimer of propionic acid reacted with about equal rate constants. A primary isotope effect was observed when carboxylic but not alkyl hydrogen was substituted by deuterium in acetic acid. The results are entirely consistent with the two-channel mechanism that we proposed for the reaction of OH with formic acid. The results are interpreted in terms of the variations in C-H bond strengths and in equilibrium constants for adduct formation of the acids studied

1989-07-05

62

Rates and mechanism of the reactions of hydroxyl radicals with acetic, deuterated acetic, and propionic acids in the gas phase  

Energy Technology Data Exchange (ETDEWEB)

Rate constants for the reactions of hydroxyl radicals with the monomer and dimer of acetic acid, deuterated acetic acids, and propionic acid have been determined by a laser photolysis-resonance absorption technique. Hydroxyl radicals were generated by photolysis of the acids at 222 nm with a KrCl laser and their decay was followed by time-resolved resonance absorption. The monomers of acetic and deuterated acetic acids reacted with OH much faster than the dimers, whereas the monomer and dimer of propionic acid reacted with about equal rate constants. A primary isotope effect was observed when carboxylic but not alkyl hydrogen was substituted by deuterium in acetic acid. The results are entirely consistent with the two-channel mechanism that we proposed for the reaction of OH with formic acid. The results are interpreted in terms of the variations in C-H bond strengths and in equilibrium constants for adduct formation of the acids studied.

Singleton, D.L.; Paraskevopoulos, G.; Irwin, R.S. (National Research Council of Canada, Ottawa, Ontario (Canada))

1989-07-05

63

Oxygen-17 and proton nuclear magnetic resonance studies on acetic acid exchange processes of the chloride, nitrate, and acetate of nickel(II) in acetic acid  

International Nuclear Information System (INIS)

The exchange rates of acetic acid coordinating to nickel(II) chloride, nickel(II) nitrate, and nickel(II) acetate in neat acetic acid and acetic acid/dichloromethane-d_2 mixtures were measured by the oxygen-17 and proton NMR line-broadening methods. The activation parameters for the acetic acid exchange on these nickel(II) salts were independent of the concentration of acetic acid (HOAc) in the mixed solvents. The first-order rate constants at 25"0C and the activation parameters are k = (5.5 +/- 0.2) x 10"5 s"-"1, ?H = 41 +/- 2 kJ mol"-"1, and ?S = 3 +/- 7 J mol"-"1 K"-"1 for NiCl_2, k = (3 +/- 1) x 10"5 s"-"1, ?H = 37 +/- 5 kJ mol"-"1, and element of = -18 +/- 20 J mol"-"1 K"-"1 for Ni(NO_3)_2, and k = (3 +/- 1) x 10"5 s"-"1, ?H = 50 +/- 5 kJ mol"-"1, and ?S = 28 +/- 20 J mol"-"1 K"-"1 for Ni(OAc)_2. Solvent exchange was proposed to proceed via a dissociative-interchange mechanisms. 34 references, 5 figures, 1 table

1985-11-07

64

Correlation of vapor - liquid equilibrium data for acetic acid - isopropanol - water - isopropyl acetate mixtures  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english A correlation procedure for the prediction of vapor - liquid equilibrium of acetic acid - isopropanol - water - isopropyl acetate mixtures has been developed. It is based on the NRTL model for predicting liquid activity coefficients, and on the Hayden-O'Connell second virial coefficients for predict [...] ing the vapor phase of systems containing association components. When compared with experimental data the correlation shows a good agreement for binary and ternary data. The correlation also shows good prediction for reactive quaternary data.

Mandagarán, B. A.; Campanella, E. A..

65

Catalysis of the Carbonylation of Alcohols to Carboxylic Acids Including Acetic Acid Synthesis from Methanol.  

Science.gov (United States)

Monsanto's highly successful synthesis of acetic acid from methanol and carbon monoxide illustrates use of new starting materials to replace pretroleum-derived ethylene. Outlines the fundamental aspects of the acetic acid process and suggests ways of extending the synthesis to higher carboxylic acids. (JN)

Forster, Denis; DeKleva, Thomas W.

1986-01-01

66

Characterization of acetic acid bacteria in "traditional balsamic vinegar".  

Science.gov (United States)

This study evaluated the glucose tolerance of acetic acid bacteria strains isolated from Traditional Balsamic Vinegar. The results showed that the greatest hurdle to acetic acid bacteria growth is the high sugar concentration, since the majority of the isolated strains are inhibited by 25% of glucose. Sugar tolerance is an important technological trait because Traditional Balsamic Vinegar is made with concentrated cooked must. On the contrary, ethanol concentration of the cooked and fermented must is less significant for acetic acid bacteria growth. A tentative identification of the isolated strains was done by 16S-23S-5S rDNA PCR/RFLP technique and the isolated strains were clustered: 32 strains belong to Gluconacetobacter xylinus group, two strains to Acetobacter pasteurianus group and one to Acetobacter aceti. PMID:16214251

Gullo, Maria; Caggia, Cinzia; De Vero, Luciana; Giudici, Paolo

2006-02-01

67

2-[4-(Carboxymethylphenoxy]acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available The title compound, C10H10O5, was obtained by the reaction of 4-hydroxyphenylacetic acid with chloroacetic acid. In the crystal, the molecules form a three-dimensional network by way of intermolecular O—H...O hydrogen bonding.

Yi-Hang Wen

2011-01-01

68

CARCINOGENICITY OF THE CHLORINATED ACETIC ACIDS  

Science.gov (United States)

Dichloroacetic Acid (DCAA) and trichloroacetic acid (TCAA) comprise a major fraction of the reaction products formed when water containing a variety of precursor humic materials is chlorinated. Both DCAA and TCAA administered in the drinking water increased the incidence of hepat...

69

Catabolism of indole-3-acetic acid and 4- and 5-chloroindole-3-acetic acid in Bradyrhizobium japonicum.  

DEFF Research Database (Denmark)

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid. Indoleacetic acid (IAA), 4-chloro-IAA (4-Cl-IAA), and 5-Cl-IAA were metabolized to different extents by strains 61A24 and 110. Metabolites were isolated and analyzed by high-performance liquid chromatography and conventional mass spectrometry (MS) methods, including MS-mass spectroscopy, UV spectroscopy, and high-performance liquid chromatography-MS. The identified products indicate a novel metabolic pathway in which IAA is metabolized via dioxindole-3-acetic acid, dioxindole, isatin, and 2-aminophenyl glyoxylic acid (isatinic acid) to anthranilic acid, which is further metabolized. Degradation of 4-Cl-IAA apparently stops at the 4-Cl-dioxindole step in contrast to 5-Cl-IAA which is metabolized to 5-Cl-anthranilic acid. Udgivelsesdato: 1995-Oct

Jensen, J B; Egsgaard, H

1995-01-01

70

Conductometric simultaneous determination of acetic acid, monochloroacetic acid and trichloroacetic acid using orthogonal signal correction-partial least squares.  

Science.gov (United States)

A simultaneous conductometric titration method for determination of mixtures of acetic acid, monochloroacetic acid and trichloroacetic acid based on the multivariate calibration partial least squares is proposed. It is possible to obtain an adjustable model to relate squared concentration values of the mixtures used in the calibration range by conductance. The effect of orthogonal signal correction (OSC) as a preprocessing technique used to remove the information unrelated to the target variables is studied. The calibration model was build using conductometric titrations data of 16 mixtures of three acids. The concentration matrix was designed by a orthogonal design. The root mean squares error of prediction (RMSEP) for acetic acid, monochloroacetic acid and trichloroacetic acid with and without OSC were 0.08, 0.30 and 0.08, and 0.15, 0.40 and 0.18, respectively. The results obtained by OSC-PLS are better than the PLS and this indicate the successful application of the OSC filter as a good preprocessing method in multivariate calibration methods. The proposed procedure allows the simultaneous determination of these acids, in the synthetic mixtures. PMID:16236436

Ghorbani, R; Ghasemi, J; Abdollahi, B

2006-04-17

71

Petrochemicals. Acetic acid, acetic esters, butanol and its derivatives; Toryo genryo yozai. 1. Sakusan, sakusan ester, butanol oyobi yudotai  

Energy Technology Data Exchange (ETDEWEB)

This paper explains manufacturing methods, properties and applications of acetic acid, acetic esters, and butanol. In spite of very simple structure composed of carboxylic acid with carbon number of two, acetic acid has a great variety of synthesizing methods, with a large number of the methods having been industrialized. The most common manufacturing method currently used is the methanol process using methanol and carbon monoxide as the raw materials. Manufacturing of acetic ester uses a method to demerize acetaldehyde under presence of aluminum alcholate. The only known method to manufacture butyl acetate is hydro-esterification from acetic acid and butanol by using a mineral acid catalyst. The mainstream method of manufacturing butanol is an oxo-synthetic method with which butylaldehyde is made through contact reaction of propylene and water gas, which is hydrogenated into butanol. Butanol may be used directly as paint, ink solvent, and pharmaceutical solvent. 6 refs., 4 figs., 2 tabs.

Inaba, S. [Daicel Chemical Industries, Ltd., Osaka (Japan)

1997-08-01

72

Molecular Interactions in Binary Mixture of Polymethylmethacrylate with Acetic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Solution is prepared by mixing Polymethylmethacrylate in solid form with acetic acid, which at differentconcentration were used to measure density, viscosity & ultrasonic velocity in the temperature range 300C-650C,using ultrasonic interferometer at 1MHz. Using these measured values of density, viscosity & sound velocity,different parameters like, adiabatic compressibility, acoustic impedance and relaxation time have been measuredfor solution of polymethylmethacrylate with acetic acid under different conditions of temperature andconcentration. Variations of above parameters with respect to temperature and concentration have beendiscussed in terms of molecular interactions.

Richa Saxena

2010-07-01

73

Fed-batch fermentation with and without on-line extraction for propionic and acetic acid production by Propionibacterium acidipropionici.  

Science.gov (United States)

Fed-batch propionic and acetic acid fermentations were performed in semi-defined laboratory medium and in corn steep liquor with Propionibacterium acidipropionici strain P9. On average, over four experiments, 34.5 milligrams propionic acid and 12.8 milligrams acetic acid were obtained in about 146 h in laboratory medium with 79 milligrams glucose added over five feeding periods. The highest concentration of propionic acid, 45 milligrams, was obtained when the glucose concentration was not allowed to drop to zero. In corn steep liquor 35 milligrams propionic acid and 11 milligrams acetic acid were produced in 108 h from 59.4 milligrams total lactic acid provided as seven feedings of corn steep liquor. Extractive fed-batch fermentations were conducted in semi-defined medium using either flat-sheet-supported liquid membranes or hollow-fiber membrane extraction to remove organic acids from the culture medium. As operated during the course of the fermentation, these systems extracted 25% and 22% of the acetic acid and 36.5% and 44.5% of the propionic acid, respectively, produced in the fermentation. Total amounts of acids produced were about the same as in comparable nonextractive fermentations: 30-37 milligrams propionic acid and 13 milligrams acetic acid were produced in 150 h. Limitations on acid production can be attributed to limited substrate feed, not to failure of the extraction system. PMID:8867628

Ozadali, F; Glatz, B A; Glatz, C E

1996-02-01

74

Mass Spectral and Electric Deflection Study of Acetic Acid Clusters.  

Science.gov (United States)

Acetic acid clusters, (CH3COOH)n, up to n = 10, were produced in a supersonic beam expansion and analyzed in a molecular beam quadrupole mass spectrometer. A general mechanism for their mass spectral fragmentation was deduced. Polarity of the first four c...

R. Sivert I. Cadez J. Van Doren A. W. Castleman

1984-01-01

75

First Acetic Acid Survey with CARMA in Hot Molecular Cores  

CERN Document Server

Acetic acid (CH$_3$COOH) has been detected mainly in hot molecular cores where the distribution between oxygen (O) and nitrogen (N) containing molecular species is co-spatial within the telescope beam. Previous work has presumed that similar cores with co-spatial O and N species may be an indicator for detecting acetic acid. However, does this presumption hold as higher spatial resolution observations become available of large O and N-containing molecules? As the number of detected acetic acid sources is still low, more observations are needed to support this postulate. In this paper, we report the first acetic acid survey conducted with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) at 3 mm wavelengths towards G19.61-0.23, G29.96-0.02 and IRAS 16293-2422. We have successfully detected CH$_3$COOH via two transitions toward G19.61-0.23 and tentatively confirmed the detection toward IRAS 16293-2422 A. The determined column density of CH$_3$COOH is 2.0(1.0)$\\times 10^{16}$ cm$^{-2}$ and the...

Shiao, Y -S Jerry; Remijan, Anthony J; Snyder, Lewis E; Friedel, Douglas N

2010-01-01

76

Molecular Interactions in Binary Mixture of Polymethylmethacrylate with Acetic Acid  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Solution is prepared by mixing Polymethylmethacrylate in solid form with acetic acid, which at differentconcentration were used to measure density, viscosity & ultrasonic velocity in the temperature range 300C-650C,using ultrasonic interferometer at 1MHz. Using these measured values of density, viscosity & sound velocity,different parameters like, adiabatic compressibility, acoustic impedanc...

Richa Saxena; Bhatt, S. C.

2010-01-01

77

Occurrence and metabolism of 7-hydroxy-2-indolinone-3-acetic acid in Zea mays  

Science.gov (United States)

7-Hydroxy-2-indolinone-3-acetic acid was identified as a catabolite of indole-3-acetic acid in germinating kernels of Zea mays and found to be present in amounts of ca 3.1 nmol/kernel. 7-Hydroxy-2-indolinone-3-acetic acid was shown to be a biosynthetic intermediate between 2-indolinone-3-acetic acid and 7-hydroxy-2-indolinone-3-acetic acid-7'-O-glucoside in both kernels and roots of Zea mays. Further metabolism of 7-hydroxy-2-[5-3H]-indolinone-3-acetic acid-7'-O-glucoside occurred to yield tritiated water plus, as yet, uncharacterized products.

Lewer, P.; Bandurski, R. S.

1987-01-01

78

3-Acet­oxy-2-naphthoic acid  

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In the title compound, C13H10O4, an analog of acetyl­salicylic acid, the naphthalene unit is twisted slightly due to ortho disubstitution [dihedral angle between conjugated rings system in the naphthalene unit = 2.0?(2)°]. The mean planes of the carb­oxy­lic and ester groups are almost coplanar and perpendicular, respectively, to the mean plane of the conjugated aromatic system, making dihedral angles of 8.9?(3) and 89.3?(1)°. In the crystal, mol­ecules are paired through their ca...

Souza, Bruno S.; Vitto, Ramon; Nome, Faruk; Kirby, Anthony J.; Bortoluzzi, Adailton J.

2010-01-01

79

Formic and acetic acid aggregation in the liquid state  

International Nuclear Information System (INIS)

The microscopic structure of neat formic and acetic acid have been measured by neutron diffraction with H/D substitution on SANDALS at the ISIS neutron spallation source. These data, together with complementary x-ray data, have been modeled via the empirical potential structure refinement (EPSR) method, which integrates information obtained from the diffraction data in a Monte Carlo simulation in order to provide a three-dimensional model of the system under study compatible with the measured structure factors. Two models have been generated for each acid, in order to test their consistency, with positive results. The final structure obtained is that of two liquids that are very similar to each other, with high connectivity although rather disordered. They present a hierarchy of probability for hydrogen bond formation, where weaker bonds involving the carbonyl hydrogen for formic acid or the methyl hydrogen for acetic acid are more abundant than the stronger bonds involving the hydroxyl hydrogen. Cooperative effects are found to be fundamental for the description of aggregation of formic and acetic acid, but the structure in the liquid presents a greater variety of bonds than in the solid state.

2010-10-13

80

Acetic acid bacteria spoilage of bottled red wine -- a review.  

Science.gov (United States)

Acetic acid bacteria (AAB) are ubiquitous organisms that are well adapted to sugar and ethanol rich environments. This family of Gram-positive bacteria are well known for their ability to produce acetic acid, the main constituent in vinegar. The oxidation of ethanol through acetaldehyde to acetic acid is well understood and characterised. AAB form part of the complex natural microbial flora of grapes and wine, however their presence is less desirable than the lactic acid bacteria and yeast. Even though AAB were described by Pasteur in the 1850s, wine associated AAB are still difficult to cultivate on artificial laboratory media and until more recently, their taxonomy has not been well characterised. Wine is at most risk of spoilage during production and the presence of these strictly aerobic bacteria in grape must and during wine maturation can be controlled by eliminating, or at least limiting oxygen, an essential growth factor. However, a new risk, spoilage of wine by AAB after packaging, has only recently been reported. As wine is not always sterile filtered prior to bottling, especially red wine, it often has a small resident bacterial population (vinegar, sherry, bruised apple, nutty, and solvent like off-aromas, depending on the degree of spoilage. This review focuses on the wine associated AAB species, the aroma and flavour changes in wine due to AAB metabolism, discusses the importance of oxygen ingress into the bottle and presents a hypothesis for the mechanism of spoilage of bottled red wine. PMID:18237809

Bartowsky, Eveline J; Henschke, Paul A

2008-06-30

 
 
 
 
81

Simultaneous removal of sulfide, nitrate and acetate under denitrifying sulfide removal condition: Modeling and experimental validation  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: Model evaluation applied to case study 1: (A-G) S{sup 2?}, NO{sub 3}{sup ?}-N, NO{sub 2}{sup ?}-N, and Ac{sup ?}-C profiles under initial sulfide concentrations of 156.2 (A), 539 (B), 964 (C), 1490 (D), 342.7 (E), 718 (F), and 1140.7 (G) mg L{sup ?1}. The solid line represents simulated result and scatter represents experimental result. -- Highlights: • This work developed a mathematical model for DSR process. • Kinetics of sulfur–nitrogen–carbon and interactions between denitrifiers were studied. • Kinetic parameters of the model were estimated via data fitting. • The model described kinetic behaviors of DSR processes over wide parametric range. -- Abstract: Simultaneous removal of sulfide (S{sup 2?}), nitrate (NO{sub 3}{sup ?}) and acetate (Ac{sup ?}) under denitrifying sulfide removal process (DSR) is a novel biological wastewater treatment process. This work developed a mathematical model to describe the kinetic behavior of sulfur–nitrogen–carbon and interactions between autotrophic denitrifiers and heterotrophic denitrifiers. The kinetic parameters of the model were estimated via data fitting considering the effects of initial S{sup 2?} concentration, S{sup 2?}/NO{sub 3}{sup ?}-N ratio and Ac{sup ?}-C/NO{sub 3}{sup ?}-N ratio. Simulation supported that the heterotrophic denitratation step (NO{sub 3}{sup ?} reduction to NO{sub 2}{sup ?}) was inhibited by S{sup 2?} compared with the denitritation step (NO{sub 2}{sup ?} reduction to N{sub 2}). Also, the S{sup 2?} oxidation by autotrophic denitrifiers was shown two times lower in rate with NO{sub 2}{sup ?} as electron acceptor than that with NO{sub 3}{sup ?} as electron acceptor. NO{sub 3}{sup ?} reduction by autotrophic denitrifiers occurs 3–10 times slower when S{sup 0} participates as final electron donor compared to the S{sup 2?}-driven pathway. Model simulation on continuous-flow DSR reactor suggested that the adjustment of hydraulic retention time is an efficient way to make the reactor tolerating high S{sup 2?} loadings. The proposed model properly described the kinetic behaviors of DSR processes over wide parametric ranges and which can offer engineers with basis to optimize bioreactor operation to improve the treatment capacity.

Xu, Xijun; Chen, Chuan; Wang, Aijie; Guo, Wanqian; Zhou, Xu [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Lee, Duu-Jong, E-mail: djlee@ntu.edu.tw [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan (China); Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Ren, Nanqi, E-mail: rnq@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Chang, Jo-Shu [Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, Taiwan (China)

2014-01-15

82

On reaction of alkali metal hexafluorogermanates with acetic acid solutions  

International Nuclear Information System (INIS)

The behaviour of K2GeF6 and Cs2GeF6 has been studied in solutions of acetic acid. The solubility isotherm has been obtained in ternary system CH3COOH-K2GeF6-H2O and CH3COOH-Cs2GeF6-H2O and the composition of the solid phases has been determined. In the system CH3COOH-K2GeF6-H2O hexafluorogermanate of potassium is a solid phase; in the system CH3COOH-Cs2GeF6-H2O the solvate Cs2GeF6x2CH3COOH is formed. The similarity has been observed in interaction of alkali metal hexafluorogermanates with solutions of acetic acid and hydrogen fluoride

1977-01-01

83

Acetic Acid Bacteria, Newly Emerging Symbionts of Insects  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Recent research in microbe-insect symbiosis has shown that acetic acid bacteria (AAB) establish symbiotic relationships with several insects of the orders Diptera, Hymenoptera, Hemiptera, and Homoptera, all relying on sugar-based diets, such as nectars, fruit sugars, or phloem sap. To date, the fruit flies Drosophila melanogaster and Bactrocera oleae, mosquitoes of the genera Anopheles and Aedes, the honey bee Apis mellifera, the leafhopper Scaphoideus titanus, and the mealybug Saccharicoccus...

Crotti, Elena; Rizzi, Aurora; Chouaia, Bessem; Ricci, Irene; Favia, Guido; Alma, Alberto; Sacchi, Luciano; Bourtzis, Kostas; Mandrioli, Mauro; Cherif, Ameur; Bandi, Claudio; Daffonchio, Daniele

2010-01-01

84

40 CFR 721.304 - Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester.  

Science.gov (United States)

...2009-07-01 2009-07-01 false Acetic acid, [(5-chloro-8-quinolinyl...Specific Chemical Substances § 721.304 Acetic acid, [(5-chloro-8-quinolinyl...The chemical substance identified as acetic acid,...

2009-07-01

85

40 CFR 180.1258 - Acetic acid; exemption from the requirement of a tolerance.  

Science.gov (United States)

...2009-07-01 2009-07-01 false Acetic acid; exemption from the requirement...Exemptions From Tolerances § 180.1258 Acetic acid; exemption from the requirement...for residues of the biochemical pesticide acetic acid when used as a...

2009-07-01

86

75 FR 52269 - Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption  

Science.gov (United States)

...EPA-HQ-OPP-2010-0429; FRL-8841-2] Acetic Acid Ethenyl Ester, Polymer With Oxirane...requirement of a tolerance for residues of acetic acid ethenyl ester, polymer with oxirane...maximum permissible level for residues of acetic acid ethenyl ester, polymer with...

2010-08-25

87

Morphological diversity of Blastocystis hominis in sodium acetate-acetic acid-formalin-preserved stool samples stained with iron hematoxylin.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objective of this investigation was to study the morphological characteristics of Blastocystis hominis in sodium acetate-acetic acid-Formalin-preserved stool samples. Routinely processed samples were examined for morphological detail, including size, shape, nuclear detail, and central body characteristics. Morphological findings revealing the importance of recognizing B. hominis in the diagnostic laboratory are described.

Macpherson, D. W.; Macqueen, W. M.

1994-01-01

88

Indole-3-acetic acid in plant-microbe interactions.  

Science.gov (United States)

Indole-3-acetic acid (IAA) is an important phytohormone with the capacity to control plant development in both beneficial and deleterious ways. The ability to synthesize IAA is an attribute that many bacteria including both plant growth-promoters and phytopathogens possess. There are three main pathways through which IAA is synthesized; the indole-3-pyruvic acid, indole-3-acetamide and indole-3-acetonitrile pathways. This chapter reviews the factors that effect the production of this phytohormone, the role of IAA in bacterial physiology and in plant-microbe interactions including phytostimulation and phytopathogenesis. PMID:24445491

Duca, Daiana; Lorv, Janet; Patten, Cheryl L; Rose, David; Glick, Bernard R

2014-07-01

89

The effect of oral sodium acetate administration on plasma acetate concentration and acid-base state in horses  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Aim Sodium acetate (NaAcetate has received some attention as an alkalinizing agent and possible alternative energy source for the horse, however the effects of oral administration remain largely unknown. The present study used the physicochemical approach to characterize the changes in acid-base status occurring after oral NaAcetate/acetic acid (NAA administration in horses. Methods Jugular venous blood was sampled from 9 exercise-conditioned horses on 2 separate occasions, at rest and for 24 h following a competition exercise test (CET designed to simulate the speed and endurance test of 3-day event. Immediately after the CETs horses were allowed water ad libitum and either: 1 8 L of a hypertonic NaAcetate/acetic acid solution via nasogastric tube followed by a typical hay/grain meal (NAA trial; or 2 a hay/grain meal alone (Control trial. Results Oral NAA resulted in a profound plasma alkalosis marked by decreased plasma [H+] and increased plasma [TCO2] and [HCO3-] compared to Control. The primary contributor to the plasma alkalosis was an increased [SID], as a result of increased plasma [Na+] and decreased plasma [Cl-]. An increased [Atot], due to increased [PP] and a sustained increase in plasma [acetate], contributed a minor acidifying effect. Conclusion It is concluded that oral NaAcetate could be used as both an alkalinizing agent and an alternative energy source in the horse.

Lindinger Michael I

2007-12-01

90

Synthesis of the [beta]-D-glucosyl ester of [carbonyl-[sup 13]C]-indole-3-acetic acid  

Energy Technology Data Exchange (ETDEWEB)

An efficient, operationally simple synthetic approach to 1-O-([carbonyl-[sup 13]C]-indole-3'-ylacetyl)-[beta]-D-glucopyranose is described. The synthesis was carried out by fusing a fully benzylated 1-O-glucosylpseudourea intermediate with [carbonyl-[sup 13]C]-indole-3-acetic acid, followed by hydrogenolytic removal of the protective groups. (Author).

Jakas, A.; Magnus, V. (Rudjer Boskovic Inst., Zagreb (Croatia)); Horvat, S.; Sandberg, G. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden))

1993-10-01

91

Detection of CIN by naked eye visualization after application of acetic acid.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A prospective study was undertaken to determine the sensitivity and specificity of acetic application to the cervix followed by naked eye visualization as a screening test for detection of cervical intraepithelial neoplasia. Three hundred and seventy two sexually active woman in the reproductive age group were studied. All the women underwent Papanicolaou test, acetic acid test and colposcopy. One hundred and seventy five woman were acetic acid test negative, 197 women were acetic acid test p...

1997-01-01

92

Recent advances in processes and catalysts for the production of acetic acid  

Energy Technology Data Exchange (ETDEWEB)

Novel acetic acid processes and catalysts have been introduced, commercialized, and improved continuously since the 1950s. The objective of the development of new acetic acid processes has been to reduce raw material consumption, energy requirements, and investment costs. At present, industrial processes for the production of acetic acid are dominated by methanol carbonylation and the oxidation of hydrocarbons such as acetaldehyde, ethylene, n-butane, and naphtha. This paper discusses advances in acetic acid processes and catalysts according to the following routes: (1) methanol carbonylation; (2) methyl formate isomerization; (3) synthesis gas to acetic acid; (4) vapor phase oxidation of ethylene, and (5) other novel technologies.

Yoneda, Noriyuki; Kusano, Satoru [Chiyoda Corporation, 3-13 Moriya-cho, Kanagawa-ku, 221-0022 Yokohama (Japan); Yasui, Makoto [Chiyoda Corporation, 2-12-1 Tsurumichuo, Tsurumi-ku, 230-8601 Yokohama (Japan); Pujado, Peter; Wilcher, Steve [UOP LLC, 25 East Algonquin Road, 60017-5017 Des Plaines, IL (United States)

2001-11-30

93

Interaction of ruthenium (3) and (4) chlorocomplexes with acetic acid  

International Nuclear Information System (INIS)

Using electron spectroscopy and cyclic voltammetry it is determined that K2[Ru(H2O)Cl5], K2[RuCl6], k4[Ru2OCl10] and 'RuOHCl3' interaction with acetic acid is a complex multiphase process. Acetate solutions of ruthenium chlorocomplexes aged under 50 deg C during 100 hs contain [Ru3(?-O)(CH3COO)6L3]n type trinuclear oxocentered acetatocomplexes, where L=H2O, CH3COO- or H2O and CH3COO- simultaneously (n=+1, 0, -1, -2) mixed-ligand aqua- or chloroacetatocomplexes of dimer structure, while in case of K2[RuCl6] and 'RuOHCl3' - mononuclear mixed-ligand complexes. 20 refs.; 2 figs.; 1 tab

1995-01-01

94

Tetra-n-propylammonium acetate–boric acid (1/1  

Directory of Open Access Journals (Sweden)

Full Text Available In the crystal structure of the ammonium carboxylate–boric acid cocrystal, (C3H74N+·CH3CO2?·H3BO3, the boric acid forms two O—H...O hydrogen bonds to the acetate anion. The acetate–boric acid species is hydrogen bonded to another acetate–boric acid species through the third OH unit of the boric acid about a twofold rotation axis.

Yun-Xia Yang

2009-11-01

95

Tetra-n-propyl­ammonium acetate–boric acid (1/1)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the crystal structure of the ammonium carboxyl­ate–boric acid cocrystal, (C3H7)4N+·CH3CO2 ?·H3BO3, the boric acid forms two O—H?O hydrogen bonds to the acetate anion. The acetate–boric acid species is hydrogen bonded to another acetate–boric acid species through the third OH unit of the boric acid about a twofold rotation axis.

Yang, Yun-xia; Li, Qi; Ng, Seik Weng

2009-01-01

96

Production of Formic Acid and Acetic Acid by Hydrothermal Oxidation of Alkali Lignin  

Science.gov (United States)

The production of formic acid and acetic acid by hydrothermal oxidation of alkali lignin, a kind of biomasses, was investigated using a batch reactor with H2O2 oxidant. Experiments were performed over a wide range of conditions with temperature varying from 260 to 320° C, oxygen supply varying from 60% to 120%, and reaction time varying from 30 to 150 s. The highest yield of formic acid was 4.9% at 280° C for 120 s with the additive ratio of H2O2 100%. The highest value of acetic acid was 12.3% at 300° C for 120 s with the additive ratio of H2O2 100%. Based on the intermediate products identified by GC/MS and HPLC, reaction pathways of alkali lignin are discussed. It was found that maleic acid and fumaric acid were two primary unsaturated intermediate products. The production of formic acid and acetic acid were come from the oxidative decomposition of intermediate products in the oxidation process. Increasing the formation of saturated dicarboxylic acids and glutaconic acid would enhance the acetic acid yield.

Zeng, Xu; Jin, Fangming; Cao, Jianglin; Yin, Guodong; Zhang, Yalei; Zhao, Jianfu

2010-11-01

97

Uranyl complexes of ?-carboxypolymethylene-diaminetetra-acetic acids  

International Nuclear Information System (INIS)

The uranyl complexes of N,N,N',N'-tetrakis(carboxymethyl)-2,3-diaminopropionic acid, N,N,N',N'-tetrakis(carboxymethyl)diaminobutyric acid, N,N,N',N'-tetrakis(carboxymethyl)ornithine and N,N,N',N'-tetrakis(carboxymethyl)lysine have been studied by potentiometry, with computer evaluation of the titration data by the MINIQUAD program. Stability constants of the 1:1 and 2:1 metal:ligand chelates have been determined as well as the hydrolysis and polymerization constants at 25"0 in 0.1M potassium nitrate. Results are compared with those obtained for the uranyl complexes of the corresponding members of the series of the polymethylenediaminetetra-acetic acids. (author)

1987-01-01

98

Role of free acetic acid on the CO{sub 2} corrosion of steels  

Energy Technology Data Exchange (ETDEWEB)

Field experience has shown that CO{sub 2}corrosion is considerably reduced at low partial pressures, unless more than 0.1 to 1 mM of acetic acid is present in the water. This paper shows that acetic species actually act as a weak inhibitor of the anodic dissolution reaction, and that the role of acetic acid is clearly related to an associated inversion of the acetate/bicarbonate ratio, together with the resulting difficulty in precipitating protective iron carbonate. In addition, despite its minute concentration, acetic acid becomes the main source of the acidity consumed by corrosion. In such conditions, a genuine acetic acid corrosion occurs, controlled by a volubility equilibrium with a gas phase containing acetic acid vapor, like in the case of CO{sub 2} corrosion.

Crolet, J.L. [Elf Exploration Production, Pau (France); Thevenot, N.; Dugstad, A. [Inst. for Energiteknikk, Kjeller (Norway)

1999-11-01

99

Probiotic and Acetic Acid Effect on Broiler Chickens Performance  

Directory of Open Access Journals (Sweden)

Full Text Available Probiotics and organic acids are widely accepted as an alternative to in-feed antibiotics in poultry production. We carried the experiment with broiler chickens. In experiment we research effect of probiotic and acetic acids on the performance of broiler chickens. A total number of 200 one day old broiler chickens were distributed to two dietary groups. Broiler chickens in control group were fed with standard feed mixture and experimental group 1% vinegar contained 5% acetic acid used in drinking water and probiotics mixed with feed mixture. Body weight, FCR and GIT pH were recorded. The performance showed no statistically significant increase in body weight (P>0.05 in the weeks 1, 2, 3 and 4 of age. The body weight of broiler chickens was significant increase (P?0.05 in weeks 5, and 6 of age. In different segments of the GIT was not statistically significant (P>0.05 difference of pH between the control and experimental groups.

Martin Král

2011-05-01

100

Environmental Risk Limits for Ethylene Diamine Tetra Acetic acid (EDTA)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this report maximum permissible concentration (MPC) and negligible concentration (NC) in water are derived for Ethylene Diamine Tetra Acetic acid (EDTA; CAS No. 64-02-8, EINECS No. 200-573-9), based on the EU risk assessment report for this compound. The Maximum Permissible Concentration (MPC) for the water compartment is 2.2 mg/l, and the Negligible Concentration (NC) is 0.022 mg/l. Calculation of MPCs for sediment or soil is not possible due to complex speciation of ...

Df, Kalf; Magt, Hoop Den; Jp, Rila; Posthuma C; Tp, Traas

2007-01-01

 
 
 
 
101

(Conversion of acetic acid to methane by thermophiles)  

Energy Technology Data Exchange (ETDEWEB)

The goal of this project is to gain a more complete understanding of the microorganisms converting a lignocellulose waste to methane in a thermophilic (58{degree}C) anaerobic bioreactor. To accomplish this, we have directly examined microbial populations in the bioreactor and have examined the properties of microorganisms isolated from the bioreactor. The primary focus has been on anaerobic thermophiles involved in the formation and degradation of acetic acid, the precursor of two thirds of the methane produced in the bioreactor. Also, novel organisms of fundamental and practical significance have been isolated and characterized. As the project has progressed there has been greater emphasis on the physiology of pure cultures. 7 refs.

Zinder, S.H.

1990-01-01

102

Radioiron utilization and gossypol acetic acid in male rats  

International Nuclear Information System (INIS)

The 24-h incorporation of 59Fe into circulating red blood cells, bone marrow, urine, liver, spleen, and skeletal muscle was measured in splenectomized and sham-splenectomized rats which had received a daily, oral dose of gossypol acetic acid (20 mg GAA/kg body wt) for 91 days. A significant decrease in total body weight gain was observed in all GAA treated animals. Splenectomized rats dosed with GAA exhibited a significant decrease in hemoglobin concentration, hematocrit and erythrocyte count. A significant increase in 59Fe incorporation by red blood cells and a decrease in hepatic incorporation of 59Fe indicate a preferential utilization of iron in erythropoiesis among GAA treated animals

1985-01-01

103

Effects of acetic acid injection and operating conditions on NO emission in a vortexing fluidized bed combustor using response surface methodology  

Energy Technology Data Exchange (ETDEWEB)

The effects of acetic acid injection and operating conditions on NO emission were investigated in a pilot scale vortexing fluidized bed combustor (VFBC), an integration of circular freeboard and a rectangular combustion chamber. Operating conditions, such as the stoichiometric oxygen in the combustion chamber, the bed temperature and the injecting location of acetic acid, were determined by means of response surface methodology (RSM), which enables the examination of parameters with a moderate number of experiments. In RSM, NO emission concentration after acetic acid injection and NO removal percentage at the exit of the VFBC are used as the objective function. The results show that the bed temperature has a more important effect on the NO emission than the injecting location of acetic acid and the stoichiometric oxygen in the combustion chamber. Meanwhile, the injecting location of acetic acid and the stoichiometric oxygen in the combustion chamber have a more important effect on the NO removal percentage than the bed temperature. NO emission can be decreased by injecting the acetic acid into the combustion chamber, and NO emission decreases with the height of the acetic acid injecting location above the distributor. On the other hand, NO removal percentage increases with the height of the acetic acid injecting location, and NO emission increases with the stoichiometric oxygen in the combustion chamber and the bed temperature. NO removal percentage increases with the stoichiometric oxygen, and increases first, then decreases with the bed temperature. Also, a higher NO removal percentage could be obtained at 850{sup o}C. 26 refs., 12 figs., 8 tabs.

Fuping Qian; Chiensong Chyang; Weishen Yen [Anhui University of Technology, Ma' anshan (China). School of Civil Engineering and Architecture

2009-07-15

104

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS)  

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Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS) can reliably quantify acetic acid vapor in ambient ...

2012-01-01

105

Anaerobic Conversion of Lactic Acid to Acetic Acid and 1,2-Propanediol by Lactobacillus buchneri  

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The degradation of lactic acid under anoxic conditions was studied in several strains of Lactobacillus buchneri and in close relatives such as Lactobacillus parabuchneri, Lactobacillus kefir, and Lactobacillus hilgardii. Of these lactobacilli, L. buchneri and L. parabuchneri were able to degrade lactic acid under anoxic conditions, without requiring an external electron acceptor. Each mole of lactic acid was converted into approximately 0.5 mol of acetic acid, 0.5 mol of 1,2-propanediol, and ...

2001-01-01

106

Anaerobic conversion of lactic acid to acetic acid and 1,2-propanediol by Lactobacillus buchneri  

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The degradation of lactic acid under anoxic conditions was studied in several strains of Lactobacillus buchneri and in close relatives such as Lactobacillus parabuchneri, Lactobacillus kefir, and Lactobacillus hilgardii. Of these lactobacilli, L. buchneri and L. parabuchneri were able to degrade lactic acid under anoxic conditions, without requiring an external electron acceptor. Each mole of lactic acid was converted into approximately 0.5 mol of acetic acid, 0.5 mol of 1,2-propanediol, and ...

2001-01-01

107

Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by etiolated and green corn tissues  

Energy Technology Data Exchange (ETDEWEB)

Etiolated corn tissues oxidase indole-3-acetic acid (IAA) to oxindole-3-acetic acid (OxIAA). This oxidation results in loss of auxin activity and may plant a role in regulating IAA-stimulated growth. The enzyme has been partially purified and characterized and shown to require O{sub 2}, and a heat-stable lipid-soluble corn factor which can be replaced by linolenic or linoleic acids in the oxidation of IAA. Corn oil was tested as a cofactor in the IAA oxidation reaction. Corn oil stimulated enzyme activity by 30% while trilinolein was inactive. The capacity of green tissue to oxidize IAA was examined by incubating leaf sections from 2 week old light-grown corn seedlings with {sup 14}C-IAA. OxIAA and IAA were separated from other IAA metabolites on a 3 ml anion exchange column. Of the IAA taken up by the sections, 13% was oxidized to OxIAA. This is the first evidence that green tissue of corn may also regulate IAA levels by oxidizing IAA to OxIAA.

Reinecke, D. (Michigan State Univ., East Lansing (USA))

1989-04-01

108

Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by etiolated and green corn tissues  

International Nuclear Information System (INIS)

Etiolated corn tissues oxidase indole-3-acetic acid (IAA) to oxindole-3-acetic acid (OxIAA). This oxidation results in loss of auxin activity and may plant a role in regulating IAA-stimulated growth. The enzyme has been partially purified and characterized and shown to require O2, and a heat-stable lipid-soluble corn factor which can be replaced by linolenic or linoleic acids in the oxidation of IAA. Corn oil was tested as a cofactor in the IAA oxidation reaction. Corn oil stimulated enzyme activity by 30% while trilinolein was inactive. The capacity of green tissue to oxidize IAA was examined by incubating leaf sections from 2 week old light-grown corn seedlings with 14C-IAA. OxIAA and IAA were separated from other IAA metabolites on a 3 ml anion exchange column. Of the IAA taken up by the sections, 13% was oxidized to OxIAA. This is the first evidence that green tissue of corn may also regulate IAA levels by oxidizing IAA to OxIAA

1989-01-01

109

ESR studies of reactions in UV-irradiated solid aqueous solution of acetic acid containing europium(III) acetate  

International Nuclear Information System (INIS)

Solid aqueous solution of acetic acid containing Eu(III) acetate and its deuterated equivalent were irradiated with lambda=254 nm at 77 K and then studied by ESR spectroscopy in the temperature range of 77-250 K. CH_3, CH_2COOH, HCO, H and their deuterated equivalents other than D were detected. It has been clarified that H is produced by the reduction of the solvent with Eu"2"+ which is formed by the charge-transfer-to-metal breakdown of the acetate ligand of Eu"3"+. (author)

1981-07-15

110

The selective generation of acetic acid directly from synthesis gas  

International Nuclear Information System (INIS)

The authors conclude that each of the ruthenium, cobalt and iodide-containing catalyst components have very specific roles to play in the ''melt'' catalyzed conversion of synthesis gas to acetic acid. C_1-Oxygenate formation is only observed in the presence of ruthenium carbonyls - [Ru(CO)_3I_3]"- is here the dominant species - and there is a direct relationship between liquid yield, ?OAc"-productivity and [Ru(CO)_3I_3]"- content. Controlled quantities of iodide ensure that initially formed MeOH is rapidly converted to the more reactive methyl iodide. Subsequent cobalt-catalyzed carbonylation to acetic acid may be preparatively attractive (>80% selectivity, good yields) relative to competing syntheses, where the [Co(CO)_4]"- concentration is maximized that is, where the Co/Ru ratio is >1, the syngas feedstock is rich in CO, and the initial iodide/cobalt ratios are ca. unity. Formation of cobalt-iodide species appears to be a competing, inhibitory step in this catalysis

1986-03-01

111

?-(Acetic acid-di-?-chlorido-bis[triphenyltellurium(IV] monohydrate  

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Full Text Available The asymmetric unit of the title compound, C38H34Cl2O2Te2·H2O, contains two independent TeIV cations, each coordinated by three phenyl ligands, two Cl? anions and one acetic acid molecule in a distorted octahedral C3Cl2O geometry; the longer Te...Cl distances ranging from 3.2007?(11 to 3.4407?(11?Å and the longer Te...O distances of 3.067?(3 and 3.113?(3?Å indicate the weak bridge coordination. The Cl? anion and acetic acid molecule bridge the two independent TeIV cations, forming the dimeric complex molecule, in which the Te...Te separation is 3.7314?(4?Å. In the crystal, the water molecules of crystallization link the TeIV complex molecules into chains running along the b-axis direction via O—H...O and O—H...Cl hydrogen bonds.

Feng Hu

2013-07-01

112

Diffusion of electrolytes in hydrolyzable glassy polymers: Acetic acid in poly(vinyl acetate), poly(vinyl alcohol), and polyesters  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Engineering materials containing poly(vinyl acetate) (PVAc) as the key component undergo hydrolytic degradation, which must be minimized or, at least, controlled. To characterize PVAc hydrolysis quantitatively, the diffusion of acetic acid (HAc) in PVAc, poly(vinyl alcohol) (PVA), unsaturated polyester (UPE), and a UPE/PVAc blend was studied in detail. The permeability cell earlier developed by the authors was modified here to reduce experimental error. As the diffusion and solubility coeffic...

Polishchuk, A. Ya; Valente, A. J. M.; Camino, G.; Luda, M. P.; Madyuskin, N. N.; Lobo, V. M. M.; Zaikov, G. E.; Revellino, M.

2002-01-01

113

Interaction effects of lactic acid and acetic acid at different temperatures on ethanol production by Saccharomyces cerevisiae in corn mash  

Energy Technology Data Exchange (ETDEWEB)

The combined effects of lactic acid and acetic acid on ethanol production by S. cerevisiae in corn mash, as influenced by temperature, were examined. Duplicate full factorial experiments (three lactic acid concentrations x three acetic acid concentrations) were performed to evaluate the interaction between lactic and acetic acids on the ethanol production of yeast at each of the three temperatures, 30, 34, and 37 C. Corn mash at 30% dry solids adjusted to pH 4 after lactic and acetic acid addition was used as the substrate. Ethanol production rates and final ethanol concentrations decreased (P<0.001) progressively as the concentration of combined lactic and acetic acids in the corn mash increased and the temperature was raised from 30 to 37 C. At 30 C, essentially no ethanol was produced after 96 h when 0.5% w/v acetic acid was present in the mash (with 0.5, 2, and 4% w/v lactic acid). At 34 and 37 C, the final concentrations of ethanol produced by the yeast were noticeably reduced by the presence of 0.3% w/v acetic acid and {>=}2% w/v lactic acid. It can be concluded that, as in previous studies with defined media, lactic acid and acetic acid act synergistically to reduce ethanol production by yeast in corn mash. In addition, the inhibitory effects of combined lactic and acetic acid in corn mash were more apparent at elevated temperatures. (orig.)

Graves, T.; Narendranath, N.V.; Dawson, K.; Power, R. [Alltech Biotechnology Center, Nicholasville, KY (United States)

2007-01-15

114

Ethenzamide–gentisic acid–acetic acid (2/1/1)  

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In the title co-crystal solvate, 2-ethoxybenzamide–2,5-dihydroxybenzoic acid–ethanoic acid (2/1/1), 2C9H11NO2·C7H6O4·C2H4O2, two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxybenzamide) and gentisic acid (systematic name: 2,5-dihydroxybenzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component molecular assembly held together by N—H...O and O—H...O hydrogen bonds. This assembly features two sym...

Srinivasulu Aitipamula; Pui Shan Chow; Tan, Reginald B. H.

2010-01-01

115

New acetic acid process based on direct oxidation of ethylene; Echiren Jikisanho sakusan shiseizoho no kaihatsu  

Energy Technology Data Exchange (ETDEWEB)

Acetyl system product such as the acetic acid has been positioned as a core product of Showa Denko, and it has the history of the long production. The extension of the acetic acid plant was planned in proportion to the demand that it entered in 1990's and is mainly vigorous of the Asia region of the acetic acid. The catalyst development of the method for synthesizing direct acetic acid from ethylene and oxygen as a new technology of the manufacturing was undertaken. (NEDO)

Sano, Ken' ichi; Nishino, Hiroshi; Iizuka, Yukio; Suzuki, Toshiro; Sasaki, Takaharu [Showa denko Corp., Tokyo (Japan)

1999-06-05

116

Removal of humic acids by flotation  

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The application of flotation for the removal of humic acids was investigated in the present study, as a possible post-treatment stage of simulated landfill leachates, i.e., after biological treatment. Several parameters were examined towards the optimization of humic acids removal; the dosage of collector was found to be the major one, controlling the overall efficiency of the process. However, the type and dosage of frother, the solution pH, ionic strength and flotation time were found to be...

Zouboulis, A. I.; ???????????, ?. ?.; Jun, W.; Katsoyiannis, I. A.; ?????????????, ?. ?.

2009-01-01

117

Anodic behavior of molybdenum in acetic acid solution  

International Nuclear Information System (INIS)

Polarization experiments were made in acetic acid solutions of pH 5 under potentiostatic and galvanostatic conditions. The passive region of molybdenum extended from -0.2 to -0.1 V (SCE) and transpassive dissolution occurred above -0.1 V. In the transpassive region, molybdenum dissolved as MoO_4"2"- via the formation of MoO(OH)_2 or Mo(OH)_4 film. The electric charges utilized in the formation of oxide film Q_1 was determined by coulometry and that of its dissolution as MoO_4"2"-Q sub(d) by colorimetric analysis. The ratio Q_1/(Q sub(d)+Q_1) was found to be 0.7. The oxide film nature showed poor adhesion and black. It is considered highly probable that the oxide film is precipitated from the solution phase via a dissolution process. (author)

1980-01-01

118

Isolation, characterization and optimization of indigenous acetic acid bacteria and evaluation of their preservation methods  

Directory of Open Access Journals (Sweden)

Full Text Available Background and Objectives: Acetic acid bacteria (AAB are useful in industrial production of vinegar. The present study aims at isolation and identification of acetic acid bacteria with characterization, optimization, and evaluation of their acetic acid productivity."nMaterials and Methods: Samples from various fruits were screened for presence of acetic acid bacteria on glucose, yeast extract, calcium carbonate (GYC medium. Carr medium supplemented with bromocresol green was used for distinguishing Acetobacter from Gluconobacter. The isolates were cultured in basal medium to find the highest acetic acid producer. Biochemical tests followed by 16S rRNA and restriction analyses were employed for identification of the isolate and phylogenic tree was constructed. Bacterial growth and acid production conditions were optimized based on optimal inoculum size, pH, temperature, agitation, aeration and medium composition."nResults: Thirty-seven acetic acid bacteria from acetobacter and gluconobacter members were isolated. Acetic acid productivity yielded 4 isolates that produced higher amounts of acid. The highest producer of acid (10.03% was selected for identification. The sequencing and restriction analyses of 16S rRNA revealed a divergent strain of Acetobacter pasteurianus (Gene bank accession number # GU059865. The optimum condition for acid production was a medium composed of 2% glucose, 2% yeast extract, 3% ethanol and 3% acid acetic at inoculum size of 4% at 3L/Min aeration level in the production medium. The isolate was best preserved in GYC medium at 12oC for more than a month. Longer preservation was possible at -70oC."nConclusion: The results are suggestive of isolation of an indigenous acetic acid bacteria. Pilot plan is suggested to study applicability of the isolated strain in acetic acid production.

K Beheshti-Maal

2010-06-01

119

Remedial methods for intergranular attack of alloy 600 tubing. Volume 3. Boric acid and acetic acid remedial methods. Final report  

International Nuclear Information System (INIS)

An important cause of recent tube degradation in recirculating pressurized water reactor (PWR) steam generators with open tube/tubesheet crevices is intergranular attack (IGA) of alloy 600 tubing in the crevice region. The attack appears to occur on the hot leg tubing because of high concentrations of caustic species formed from remnants of past phosphate water treatment, combined with materials from inleakage from freshwater-cooled condensers. The concept of using neutralizers to modify the aggressiveness of the crevice environment was examined. It appears that this can be accomplished by neutralizing the caustic species with an acid. Two ways to apply the acid are by off-line flushing during plant shutdown and by on-line treatment during operation. The substance that appears to be most suitable for off-line flushing is acetic acid, with boric acid as a second choice. Concentrations should be in the range of from 1000 to 5000 ppM. The addition of 1000 to 5000 ppM of a non-ionic detergent in the flush solution should improve penetration of the crevice. Use of preflush lancing to remove sludge on the tubesheet will also help by reducing acid consumption. The requirements for materials to be used in on-line treatment are more stringent because of possible interaction with other components in the secondry system. Boric acid is the only substance that has operational experience. A series of tests are proposed to investigate the behavior of acetic acid and boric acid on tubesheet sludge, on tubesheet/support plate material, and on alloy 600/tubesheet couples. Similarly, areas of uncertainty of on-line treatment with boric acid are its effect on tubesheet/support plate materials and on the rest of the secondary system. 23 refs

1986-01-01

120

Studies on sup(14)COsub(2) exchange reaction with p-fluorophenyl acetic acid and microsynthesis of carboxyl-sup(14)C labelled p-fluorophenyl acetic acid  

International Nuclear Information System (INIS)

The exchange reaction between sup(14)COsub(2) and sodium salt of p-fluorophenyl acetic acid was found to proceed with greater than 50% isotope incorporation when salt to COsub(2) ratio was 6:1. The carboxyl-C-14 labelled p-fluorophenyl acetic acid was isolated in a pure form using small chemical concentrations of radioactive sup(14)COsub(2) of high specific activity (30 mCi/mmol). (author)

1986-03-10

 
 
 
 
121

Effect of Exogenous Indole-3-acetic Acid and Naphthalene Acetic Acid on Regeneration of Damask Rose Cuttings in Three Growing Media  

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An experiment was conducted to evaluate the performance of various levels of indole-3-acetic acid (IAA) and naphthalene acetic acid (NAA) treatments i.e., 0, 25, 50, 75, 100 mg L-1 on the regeneration of damask rose (Rosa damascena Mill.) cuttings in different growing media at the research farm of Arid Zone Research Institute D.I. Khan during 2004. The data revealed significant effect of different levels of growth regulators and growing media on the rose establishment parame...

Rahmat Ullah Khan; Muhammad Sohail Khan; Abdur Rashid; Muhammad Arshad Farooq

2007-01-01

122

Acetic acid enhanced purification of crude cellulose from sugarcane bagasse: Structural and morphological characterization  

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Full Text Available Crude cellulose prepared from alkali-extracted sugarcane bagasse was subjected to a rapid purification treatment with a mixture of 80% acetic acid-68% nitric acid (10/1, v/v at 120 °C for 15 min. The yields of the preparations decreased slightly from 57.3%-58.6% in the crude cellulose preparations to 50.3%-51.9% in the purified cellulose samples. The purification treatment removed large amounts of resistant hemicelluloses strongly associated to the cellulose. XRD analysis revealed that the structure of both the crude and purified cellulose was cellulose I. Compared to the crude cellulose, a slight increase in the crystallinity index of the purified cellulose was observed by FTIR, XRD, and CP/MAS 13C NMR analyses. In addition, SEM showed that the macrofibril surface of the crude cellulose was almost free of trenches, but many terraces, steps, and kinks formed in the preparations after the purification.

Jing Bian

2012-11-01

123

Effects of acetylsalicylic acid and acetic acid solutions in VX2 carcinoma cells: In vitro analysis  

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Full Text Available PURPOSE: To analyze, in vitro, the effects of acetylsalicylic acid (aspirin and acetic acid solutions on VX2 carcinoma cells in suspension and to examine the correlation between these effects and neoplastic cell death. METHODS: The VX2 tumor cells (10(7 cells/ml were incubated in solutions containing differing concentrations (2.5% and 5% of either acetylsalicylic acid or acetic acid, or in saline solution (controls. Every five minutes, cell viability was tested (using the trypan blue test and analyzed under light microscopy. RESULTS: Tumor cell viability (in % decreased progressively and, by 30 minutes, neoplastic cell death had occurred in all solutions. CONCLUSION: Based on this experimental model and the methodology employed, we conclude that these solutions cause neoplastic cell death in vitro.

Saad-Hossne Rogério

2006-01-01

124

Development of xylose-fermenting yeasts for ethanol production at high acetic acid concentrations  

Energy Technology Data Exchange (ETDEWEB)

Mutants resistant to comparatively high levels of acetic acid were isolated from the xylose-fermenting yeasts Candida shehatae and Pichia Stipitis by adapting these cultures to increasing concentrations of acetic acid grown in shake-flask cultures. These mutants were tested for their ability to ferment xylose in presence of high acetic acid concentrations, in acid hydrolysates of wood, and in hardwood spent sulfite liquor, and compared with their wild-type counterparts and between themselves. The P. stipitis mutant exhibited faster fermentation times, better tolerance to acid hydrolysates, and tolerance to lower pH.

Mohandas, D.V.; Whelan, D.R.; Panchal, C.J. [Vetrogen Corporation, London, Ontario (Canada)

1995-12-31

125

Corrosion of hardened cement paste by acetic and nitric acids; Part 1: Calculation of corrosion depth  

Energy Technology Data Exchange (ETDEWEB)

The rate of corrosion of hardened cement paste in solutions of nitric, hydrochloric, sulfuric, acetic and formic acids was compared. Corrosion in solutions of acetic and nitric acids with different concentrations was studied in more detail. The results made it possible to obtain the relationships expressing the influence of concentration and the time of action of acid solutions on the depth of corrosion. The rates of corrosion in nitric acid solutions during the first 3 years were about 2 to 4 times that in acetic acid solutions, depending on the concentration.

Pavlik, V. (Slovak Technical Univ., Bratislava (Slovakia). Dept. of Building Materials and Prefabrication)

1994-01-01

126

High concentration preferential adsorption of zinc acetate onto acid treated activated carbon for impregnation purposes  

International Nuclear Information System (INIS)

Impregnation of activated carbon has long been the subject of researchers working in the area of protection against air pollutants, especially those interested in making personal protective equipments. People who are involved in research of heavy metal removal using activated carbon have worked at very low concentrations. Moreover, the literature available in the open domain does not reveal the secrets of working at high concentration i.e., greater than 1 mM. Working at higher salt concentrations is necessary for the purpose of impregnating the activated carbon to a certain level with metals like copper, zinc, silver, chromium, tungsten, molybdenum etc. Activated carbon impregnated with these metals can be very effective in the removal of certain toxic gases. A locally available microporous activated carbon GAC89 was pretreated with nitric acid. B.E.T. surface areas and Boehm titrations were done. A large range of concentrations of aqueous solution of zinc acetate which is a preferentially adsorbing salt was made and stirred with the raw AC and the pretreated AC. Atomic absorption spectroscopy was employed to determine the amount of zinc acetate actually adsorbed onto the carbon sample. The results were fitted to a sum of two distinct adsorption isotherms, one for low concentrations i.e., less than 1 mM, and the other for high concentrations. The lower concentration adsorption is largely influenced by the solution pH. It is observed that at higher concentrations, the adsorption is weaker and the underlying mechanism is under study. (author)

2009-01-01

127

Removal of ovarian hormones affects the ageing process of acetate metabolism  

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Full Text Available Background: Despite a close association between gastrointestinal motility and sex hormones, it has been unknown whether ovarian hormones affect absorption and metabolism of nutrients. The aim of this study is, therefore, to evaluate metabolism of acetate in rats with age and the influence of ovariectomy on its change. Methods: Fourteen female rats of the F344 strain were used, and 13C-acetate breath test was performed at 2, 7 and 13 months of age. Seven rats were ovariectomized at three weeks of age (ovariectomy group and the remaining seven rats were studied as control group. After 24-hr fasting, rats are orally administrated 1ml of water containing sodium 13C-acetate (100mg/kg and housed in an animal chamber. The expired air in the chamber is collected in a breath-sampling bag using a aspiration pump. The 13CO2 concentration is measured using an infrared spectrometer for 120 min and expressed as delta per mil. Results: The breath 13CO2 excretion increased with time and peaked 30 min in control rats. In ovariectomized rats, thee peak time of 13CO2 excretion was prolonged to 40 min at 7 and 13 months of age. Cmax was significantly higher at 2 months of age but lower at 4 months of age in ovariectomized rats than in control rats. Those of two groups became equal at 7 months of age. Conclusions: From the viewpoint of acetate metabolism, removal of ovarian hormones might make rats to be precocious ones and accelerate ageing.

Tsunehiko Imai

2009-07-01

128

Kinetics of reaction between acetic acid and Ag2+ in nitric acid medium  

International Nuclear Information System (INIS)

The reaction kinetics between acetic acid and Ag2+ in nitric acid medium is studied by spectrophotometry. The effects of concentrations of acetic acid (HAc), H+, NO3- and temperature on the reaction are investigated. The rate equation has been determined to be -dc(Ag2+)/dt=kc(Ag2+)c(HAc)c-1(H+), where k = (610±15) (mol/L)-1·min-1 with an activation energy of about (48.8±3.5) kJ·mol-1 when the temperature is 25degC and the ionic strength is 4.0 mol/L. The reduction rate of Ag2+ increases with the increase of HAc concentration or temperature and the decrease of HNO3 concentration. However, the effect of NO3- concentrations on the reaction rate is negligible. (author)

2011-12-11

129

Enzymatic hydrolysis and fermentability of corn stover pretreated by lactic acid and/or acetic acid  

DEFF Research Database (Denmark)

Four different pretreatments with and without addition of low concentration organic acids were carried out on corn stover at 195 °C for 15 min. The highest xylan recovery of 81.08% was obtained after pretreatment without acid catalyst and the lowest of 58.78% after pretreatment with both acetic and lactic acid. Glucan recovery was less sensitive to the pretreatment conditions than xylan recovery. The pretreatment with acetic and lactic acid yielded the highest glucan recovery of 95.66%. The glucan recoveries of the other three pretreatments varied between 83.92% and 94.28%. Fermentability tests were performed on liquors obtained from all pretreatments and there were no inhibition effect found in any of the liquors. Simultaneous saccharification and fermentation (SSF) of water-insoluble solids (WIS) showed that a high ethanol yield of 88.7% of the theoretical based on glucose in the raw material was obtained following pretreatment at 195 °C for 15 min with acetic acid employed. The estimated total ethanol production was 241.1 kg/ton raw material by assuming fermentation of both C-6 and C-5, and 0.51 g ethanol/g sugar.

Xu, Jian; Thomsen, Mette Hedegaard

2009-01-01

130

Actinide removal from nitric acid waste streams  

International Nuclear Information System (INIS)

Actinide separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery and americium removal from nitric acid waste streams generated by plutonium purification operations. Capacity and breakthrough studies show anion exchange with Dowex 1 x 4 (50 to 100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO (tri-n-octyl-phosphine oxide) on XAD-4 removes the final traces of plutonium, including hydrolytic polymer. Partial neutralization and solid supported liquid membrane transfer removes americium for sorption on discardable inorganic ion exchangers, potentially allowing for non-TRU waste disposal

1986-01-01

131

Simple analytical method for organophosphorus pesticide determination in unpolished rice, using removal of fats by zinc acetate.  

Science.gov (United States)

A rapid and simple method is developed for the determination of organophosphorus pesticides in unpolished rice. The new method incorporated acetonitrile-water (1 + 1) extraction, removal of fats by zinc acetate, and further cleanup on an activated charcoal chromatographic column. The higher fatty acids in the extract react rapidly with zinc acetate to form insoluble zinc carboxylates, which precipitate. Additional interferences were cleaned up on an activated charcoal chromatographic column, and organophosphorus pesticides adsorbed on the activated charcoal were eluted with acetone-hexane. Dimethoate is not retained on the activated charcoal and must be extracted with dichloromethane from the first acetonitrile-water eluate. Pesticides are measured by flame photometric gas chromatography. Recoveries from 50 g unpolished rice samples fortified with 5-50 micrograms diazinon, 6-30 micrograms parathion, 8-40 micrograms fenitrothion and IBP, 10-50 micrograms dimethoate and fenthoate, 20-100 micrograms malathion, or 40-200 micrograms EPN ranged from 75.7 to 95.8%. PMID:6469915

Adachi, K; Ohokuni, N; Mitsuhashi, T

1984-01-01

132

Mechanism of anodic dissolution of iron in acetic acid solution  

International Nuclear Information System (INIS)

The catalytic mechanism of the spontaneous dissolution of iron was proved by combined electro- and radiochemical (ER) methods and by the measurement of the amount of the absorbed O_2. Acidic solution (20%) of sodium acetate (pH=3.7) and Fe"5"9 isotope produced by neutron irradiation were used to measure the corrosion rate of iron containing 0.005% carbon. The iron dissolves electrochemically as Fe?Fe"2"++2e, measured by the ER methods. The Fe"3"++e?Fe"2"+ reaction and the autocatalytic dissolution of iron were proved as well. The elementary steps of the chemical reaction: 4Fe"2"++O_2+4H"+?4Fe"3"++2H_2O were experimentally verified. It has been demonstrated by both methods that the reduction of Fe"3"+ ions at the electrode as well as the oxidation of Fe"2"+ ions by chemical reaction are processes of high speed so they may cause high corrosion rate. (Sz.J.)

1982-01-01

133

Radioimmunoassay of 5-hydroxyindole acetic acid using an iodinated derivative  

International Nuclear Information System (INIS)

A radioimmunoassay for the main catabolite of serotonin, 5-hydroxyindole acetic acid (5-HIAA), was developed by using specific antibodies and iodinated derivative. The synthesis of a "1"2"5I-iodinated analog was performed by coupling 5-HIAA to [125I-]glycyl-tyrosine without any contact between 5-HIAA and iodine or chloramine T. It was purified on a G25 Sephadex column and diluted in citrate buffer up to 2.5 X 10(5) cpm/ml. Antibodies were obtained by coupling 5-HIAA to human serum albumin with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and tested by equilibrium dialysis. After the third immunogen injection, the four rabbits gave antisera capable of binding 50% of iodinated 5-HIIA-glycyl-tyrosine at 1/2000 final dilution. A chemical conversion of the biological samples gives to the antigen molecules a better resemblance to the immunogen, thus conferring a 100-fold gain in specificity and sensitivity. This assay allows 5-HIAA to be determined in small amounts of tissue, blood, cerebrospinal fluid or perfusate without purification with a sensitivity threshold below 0.1 ng. Some applications in cat and rat are presented

1981-01-01

134

Acetic acid bacteria isolated from grapes of South Australian vineyards.  

Science.gov (United States)

Acetic acid bacteria (AAB) diversity from healthy, mould-infected and rot-affected grapes collected from three vineyards of Adelaide Hills (South Australia) was analyzed by molecular typing and identification methods. Nine different AAB species were identified from the 624 isolates recovered: Four species from Gluconobacter genus, two from Asaia and one from Acetobacter were identified by the analysis of 16S rRNA gene and 16S-23S rRNA gene internal transcribed spacer. However, the identification of other isolates that were assigned as Asaia sp. and Ameyamaea chiangmaiensis required more analysis for a correct species classification. The species of Gluconobacter cerinus was the main one identified; while one genotype of Asaia siamensis presented the highest number of isolates. The number of colonies recovered and genotypes identified was strongly affected by the infection status of the grapes; the rot-affected with the highest number. However, the species diversity was similar in all the cases. High AAB diversity was detected with a specific genotype distribution for each vineyard. PMID:24681711

Mateo, E; Torija, M J; Mas, A; Bartowsky, E J

2014-05-16

135

Neptunium salts with certain acetic acid derivatives, synthesis and properties  

Energy Technology Data Exchange (ETDEWEB)

A study was performed to develop preparation of neptunium (V) salts with aminoacetic, glycolic, and trichloroacetic acids. Crystalline NpO{sub 2}(CH{sub 2}OHCOO). H{sub 2}O (I) and NpO{sub 2}(CC1{sub 3}COO).H{sub 2}O (II) were synthesized. Their lattice parameters [I: rhombic, a = 13.440(2), b = 8.755(2), c = 5.711(1) {Angstrom}; II; monoclinic, a - 12.836(4), b = 11.308(3), c = 5.875(1) {Angstrom},{beta} - 99.83(4){degrees}] were determined, and IR and electronic absorption spectra were measured. The main band of NpO{sup +}{sub 2}ion (980 nm) is electronic absorption spectra of I and II is shifted toward longer waves by 16 and 21 nm, indicating cation-cation interactions in the lattice. Behavior of the compounds at heating in air was studied. Compound I loses water in the 200-350{degrees}C range with simultaneous decomposition to NpO{sub 2}. At 210{degrees}C, compound II is converted into intermediate NpOC1{sub 2}, which then decomposes to NpO{sub 2}. Main physiochemical properties of I and II were compared with properties of Np(V) acetate.

Charushnikova, I.A.; Afonas`eva, T.V.; Krot, N.N. [Institute of Physical Chemistry, Moscow (Russian Federation)

1995-01-01

136

The in vivo interaction between flavone acetic acid and hyperthermia  

DEFF Research Database (Denmark)

The in vivo interaction between flavone acetic acid (FAA) and hyperthermia was studied in a C3H mammary carcinoma grown in the feet of female CDF1 mice and in normal foot skin. FAA was intraperitoneally injected prior to local tissue heating in restrained non-anaesthetized animals. Alone, FAA at doses of 100 mg/kg and above, inhibited tumour growth in a dose-dependent fashion. FAA also enhanced the tumour response to heat, the effect being dependent on both the time interval between the two modalities and the FAA dose, the greatest effect occurring when FAA doses of > or = 150 mg/kg preceeded heat by 3-48 h. These effects of FAA correlated with the drug's ability to decrease tumour blood perfusion measured using the RbCl extraction procedure. Injecting 150 mg/kg FAA 3 h before heating (42.7 degrees C) resulted in a 2.2-fold increase in tumour heat damage, but had little effect on the response of normal foot skin in non-tumour-bearing mice. However, this treatment gave a 2.0-fold increase in normal tissue damage when the skin experiments were repeated in tumour-bearing animals. These effects in skin occurred in the absence of any blood perfusion changes, but appeared to be associated with FAA-induced TNF-alpha production.

Horsman, Michael Robert; Sampson, L E

1996-01-01

137

Improving the quality of regenerated acetic acid in the production of polyvinyl alcohol  

Energy Technology Data Exchange (ETDEWEB)

Impurities in acetic acid used for synthesis of vinyl acetate adversely affect the quality of the latter. The most undesirable admixture is crotonaldehyde, the concentration of which in acetic acid regeneration from methanol distillates varies over wide limits, reaching 0.5%. According to requirements placed on acetic acid to be used for vinyl acetate synthesis, it must not exceed 0.1%. The reasons for formation and accumulation of crotonaldehyde in the acetic acid regeneration step were identified and the condition of its redistribution between the distillate of column 5 and the acetic acid taken from this column were determined. Analysis allowed optimum conditions to be recommended for operation of the extractive regeneration column: temperature in the middle part of the column 105-110/sup 0/C (instead of 98-104/sup 0/C) and benzene consumption rate 9-10 m/sup 3//hr (instead of 5-6 m/sup 3//hr). The amount of crotonaldehyde in acetic acid produced under the recommended conditions does not exceed 0.04%.

Derevyanko, R.S.; Kulik, V.N.; Isakov, N.S.; Seryi, Y.I.; Novikov, A.I.

1983-02-01

138

Beneficial Effect of Acetic Acid on the Xylose Utilization and Bacterial Cellulose Production by Gluconacetobacter xylinus.  

Science.gov (United States)

In this work, acetic acid was found as one promising substrate to improve xylose utilization by Gluconacetobacter xylinus CH001. Also, with the help of adding acetic acid into medium, the bacterial cellulose (BC) production by G. xylinus was increased significantly. In the medium containing 3 g l(-1) acetic acid, the optimal xylose concentration for BC production was 20 g l(-1). In the medium containing 20 g l(-1) xylose, the xylose utilization and BC production by G. xylinus were stimulated by acetic acid within certain concentration. The highest BC yield (1.35 ± 0.06 g l(-1)) was obtained in the medium containing 20 g l(-1) xylose and 3 g l(-1) acetic acid after 14 days. This value was 6.17-fold higher than the yield (0.21 ± 0.01 g l(-1)) in the medium only containing 20 g l(-1) xylose. The results analyzed by FE-SEM, FTIR, and XRD showed that acetic acid affected little on the microscopic morphology and physicochemical characteristics of BC. Base on the phenomenon observed, lignocellulosic acid hydrolysates (xylose and acetic acid are main carbon sources present in it) could be considered as one potential substrate for BC production. PMID:24891733

Yang, Xiao-Yan; Huang, Chao; Guo, Hai-Jun; Xiong, Lian; Luo, Jun; Wang, Bo; Chen, Xue-Fang; Lin, Xiao-Qing; Chen, Xin-De

2014-09-01

139

Effect of Tris-acetate buffer on endotoxin removal from human-like collagen used biomaterials.  

Science.gov (United States)

Protein preparation, which has active ingredients designated for the use of biomaterials and therapeutical protein, is obtained by genetic engineering, but products of genetic engineering are often contaminated by endotoxins. Because endotoxin is a ubiquitous and potent proinflammatory agent, endotoxin removal or depletion from protein is essential for researching any biomaterials. In this study, we have used Tris-acetate (TA) buffer of neutral pH value to evaluate endotoxins absorbed on the Pierce high-capacity endotoxin removal resin. The effects of TA buffer on pH, ionic strength, incubation time as well as human-like collagen (HLC) concentration on eliminating endotoxins are investigated. In the present experiments, we design an optimal method for TA buffer to remove endotoxin from recombinant collagen and use a chromogenic tachypleus amebocyte lysate (TAL) test kit to measure the endotoxin level of HLC. The present results show that, the endotoxins of HLC is dropped to 8.3EU/ml at 25mM TA buffer (pH7.8) with 150mM NaCl when setting incubation time at 6h, and HLC recovery is about 96%. Under this experimental condition, it is proved to exhibit high efficiencies of both endotoxin removal and collagen recovery. The structure of treated HLC was explored by Transmission Electron Microscopy (TEM), demonstrating that the property and structure of HLC treated by TA buffer are maintained. Compared to the most widely used endotoxin removal method, Triton X-114 extraction, using TA buffer can obtain the non-toxic HLC without extra treatment for removing the toxic substances in Triton X-114. In addition, the present study aims at establishing a foundation for further work in laboratory animal science and providing a foundation for medical grade biomaterials. PMID:25063101

Zhang, Huizhi; Fan, Daidi; Deng, Jianjun; Zhu, Chenghui; Hui, Junfeng; Ma, Xiaoxuan

2014-09-01

140

Acetic acid bacteria in traditional balsamic vinegar: phenotypic traits relevant for starter cultures selection.  

Science.gov (United States)

This review focuses on acetic acid bacteria in traditional balsamic vinegar process. Although several studies are available on acetic acid bacteria ecology, metabolism and nutritional requirements, their activity as well as their technological traits in homemade vinegars as traditional balsamic vinegar is not well known. The basic technology to oxidise cooked grape must to produce traditional balsamic vinegar is performed by the so called "seed-vinegar" that is a microbiologically undefined starter culture obtained from spontaneous acetification of previous raw material. Selected starter cultures are the main technological improvement in order to innovate traditional balsamic vinegar production but until now they are rarely applied. To develop acetic acid bacteria starter cultures, selection criteria have to take in account composition of raw material, acetic acid bacteria metabolic activities, applied technology and desired characteristics of the final product. For traditional balsamic vinegar, significative phenotypical traits of acetic acid bacteria have been highlighted. Basic traits are: ethanol preferred and efficient oxidation, fast rate of acetic acid production, tolerance to high concentration of acetic acid, no overoxidation and low pH resistance. Specific traits are tolerance to high sugar concentration and to a wide temperature range. Gluconacetobacter europaeus and Acetobacter malorum strains can be evaluated to develop selected starter cultures since they show one or more suitable characters. PMID:18177968

Gullo, Maria; Giudici, Paolo

2008-06-30

 
 
 
 
141

Removal of radionuclides by reverse osmosis using a cellulose acetate membrane, (2)  

International Nuclear Information System (INIS)

Experiments were performed on the removal of radionuclides from radioactive liquid waste by reverse osmosis using asymmetric cellulose acetate membranes. In previous papers, we reported such removal properties as the dependence on solute concentration and the influence of co-existing material. In this paper we performed experiments on some separation properties, especially on the formation and the disappearance of concentration polarization layer of membrane surface. These experiments are necessary for the theoretical explanation of findings shown in previous papers. Concentration polarization layer is formed on the surface of the membrane, when pressurized feed solution is not stirred during reverse osmosis operation. This layer grows with elapsed time and reaches the equilibrium. The thickness of this concentration polarization layer and solute concentrations in this layer are calculated by a simple model. The formation and disappearance of this layer are experimented with intermittent stirring. The influence of intensity of stirring on the formation of concentration polarization layer is observed. These are important information on property of membrane for removing solute by reverse osmosis. (author)

1990-01-01

142

Acetic acid as a sclerosing agent for renal cysts: Comparison with ethanol in follow-up results  

International Nuclear Information System (INIS)

Purpose: To compare follow-up results of sclerotherapy for renal cyst using 50% acetic acid with those using 99% ethanol as sclerosing agents.Methods: Eighty-one patients underwent sclerotherapy and 58 patients, 23 males, 35 females, aged 6-76 years, having a total of 60 cysts, were included in this study; the others were lost to follow-up. The renal cysts were diagnosed by sonography, computed tomography (CT), or magnetic resonance imaging (MRI). Sclerotherapy was performed using 50% acetic acid for 32 cysts in 3 1 patients and 99% ethanol for 28 cysts in 27 patients. Under fluoroscopic guidance, cystic fluid was aspirated as completely as possible. After instillation of a sclerosing agent corresponding to 1 1.7%-25% (4-100 ml) of the aspirated volume, the patient changed position for 20 min and then the agent was removed. Patients were followed up by sonography for a period of 1-49 months. The volume of the renal cyst after sclerotherapy was compared with that of the renal cyst calculated before sclerotherapy. Medical records were reviewed to analyze complications.Results: The mean volume after sclerotherapy of the 17 cysts followed for 3-4 months in the acetic acid group was 5.1% of the initial volume, and for the 14 cysts in the ethanol group it was 10.2%. Complete regression during follow-up was shown in 21 cysts (66%) in the acetic acid group; the mean volume of these cysts before the procedure was 245 ml. The mean volume of the nine (32%) completely regressed cysts in the ethanol group was 184 ml. Mild flank pain, which occurred in three patients in each group, was the only complication and resolved the next day.Conclusion: Acetic acid was an effective and safe sclerosing agent for renal cysts, tending to induce faster and more complete regression than ethanol.

2000-05-01

143

Acetic Acid as a Sclerosing Agent for Renal Cysts: Comparison with Ethanol in Follow-Up Results  

International Nuclear Information System (INIS)

Purpose: To compare follow-up results of sclerotherapy for renal cyst using 50% acetic acid with those using 99% ethanol as sclerosing agents.Methods: Eighty-one patients underwent sclerotherapy and 58 patients, 23 males, 35 females, aged 6-76 years, having a total of 60 cysts, were included in this study; the others were lost to follow-up. The renal cysts were diagnosed by sonography, computed tomography (CT), or magnetic resonance imaging (MRI). Sclerotherapy was performed using 50% acetic acid for 32 cysts in 31 patients and 99% ethanol for 28 cysts in 27 patients. Under fluoroscopic guidance, cystic fluid was aspirated as completely as possible. After instillation of a sclerosing agent corresponding to 11.7%-25% (4-100 ml) of the aspirated volume, the patient changed position for 20 min and then the agent was removed. Patients were followed up by sonography for a period of 1-49 months. The volume of the renal cyst after sclerotherapy was compared with that of the renal cyst calculated before sclerotherapy. Medical records were reviewed to analyze complications.Results: The mean volume after sclerotherapy of the 17 cysts followed for 3-4 months in the acetic acid group was 5.1% of the initial volume, and for the 14 cysts in the ethanol group it was 10.2%. Complete regression during follow-up was shown in 21 cysts (66%) in the acetic acid group; the mean volume of these cysts before the procedure was 245 ml. The mean volume of the nine (32%) completely regressed cysts in the ethanol group was 184 ml. Mild flank pain, which occurred in three patients in each group, was the only complication and resolved the next day.Conclusion: Acetic acid was an effective and safe sclerosing agent for renal cysts, tending to induce faster and more complete regression than ethanol

2000-03-01

144

Deprotection of Acetals and Ketals by Silica Sulfuric Acid and Wet SiO2  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via covalent bonds. A combination of silica sulfuric acid and wet SiO2 was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives under thermal conditions.

BiBi Fathemeh Mirjalili; Mohamad Ali Zolfigol; Abdolhamid Bamoniri

2002-01-01

145

Amperometric titration of thorium and some lanthanoids in acetic-acid medium using two indicator electrodes  

International Nuclear Information System (INIS)

The votammetric behaviour of nitriletrimethylphosphonic acid (NTMP) in the medium of anhydrous acetic acid with different backgrounds in the anode region of polarization of a platinum microdisk electrode, is studied. The optimal conditions are found for the amperometric titration with two indicator electrodes of thorium and same lanthanides by a NTMP solution in anhydrous acetic medium. The influence of foreign anions and cations on the results of titration by the NTPM solution in anhydrous acetic acid is studied. The selectivity of titration in anhydrous medium is higher than in aqueous

1979-06-01

146

Photocatalytic decomposition of water and acetic acid using a powder-layer photoelectrochemical structure  

Energy Technology Data Exchange (ETDEWEB)

Nonmetallized TiO/sub 2/ powder incorporated into a thin (a few microns), porous, layer above a metallized substrate has been used to photosensitize the decompositions of water and acetic acid in an aqueous gas-phase environment. Quantum efficiencies 0.35% and 11%, respectively, show that this structure has a catalytic activity comparable to dispersions of partially metallized powders. Decomposition products in the case of acetic acid support the photoelectrochemical mechanism used to described the activity of the powder-layer structure. Evidence is given for the involvement of water in the photoreactions of acetic acid.

Hetrick, R.E.

1985-01-01

147

Theophylline-7-acetic acid derivatives with amino acids as anti-tuberculosis agents.  

Science.gov (United States)

A series of amides were synthesized by condensation of theophylline-7-acetic acid and eight commercially available amino acid methyl ester hydrochlorides. Consecutive hydrolysis of six of the amido-esters resulted in the formation of corresponding amido-acids. The newly synthesized compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv. The activity varied depending on the amino acid fragments and in seven cases exerted excellent values with MICs 0.46-0.26?M. Assessment of the cytotoxicity revealed that the compounds were not cytotoxic against the human embryonal kidney cell line HEK-293T. The theophylline-7-acetamides containing amino acid moieties appear to be promising lead compounds for the development of antimycobacterial agents. PMID:24878196

Voynikov, Yulian; Valcheva, Violeta; Momekov, Georgi; Peikov, Plamen; Stavrakov, Georgi

2014-07-15

148

Structure-related lower surface resistivity and faster doping of poly(thiophene-3-acetic acid-co-3-hexylthiophene) compared with poly(thiophene-3-acetic acid)  

International Nuclear Information System (INIS)

Two types of electrically active polymers, namely poly(thiophene-3-acetic acid-co-3-hexylthiophene) or poly(TAA-co-HT), and poly(thiophene-3-acetic acid) or PTAA were synthesized by oxidizing polymerization, and compared in terms of structure, surface resistivity and doping rate. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy data revealed that there is a smaller content of acetic acid functional groups in poly(TAA-co-HT) than in PTAA. Importantly, poly(TAA-co-HT) showed lower surface resistivity and higher doping rate when doped with iodine vapor in comparison with PTAA. The different surface resistivities and doping rates of the two polymers are related with the differences in their relative abundance of polar side groups and packing density of the polymer chains

2008-11-15

149

Adsorptive removal of phenolic compounds using cellulose acetate phthalate–alumina nanoparticle mixed matrix membrane  

International Nuclear Information System (INIS)

Highlights: • Composite membrane of cellulose–acetate–phthalate and alumina nanoparticle is cast. • Surface charge of the membrane changes with nanoparticle concentration and pH. • Separation of phenolic compounds occurs due to adsorption. • The removal efficiency is maximum for 20% nanoparticle with 91% removal of catechol. • Transmembrane pressure drop has negligible effect on solute separation. -- Abstract: Mixed matrix membranes (MMMs) were prepared using alumina nanoparticles and cellulose acetate phthalate (CAP) by varying concentration of nanoparticles in the range of 10 to 25 wt%. The membranes were characterized by scanning electron micrograph, porosity, permeability, molecular weight cut off, contact angle, surface zeta potential, mechanical strength. Addition of nanoparticles increased the porosity, permeability of the membrane up to 20 wt% of alumina. pH at point of zero charge of the membrane was 5.4. Zeta potential of the membrane became more negative up to 20 wt% of nanoparticles. Adsorption of phenolic derivatives, catechol, paranitrophenol, phenol, orthochloro phenol, metanitrophenol, by MMMs were investigated. Variation of rejection and permeate flux profiles were studied for different solutes as a function of various operating conditions, namely, solution pH, solute concentration in feed and transmembrane pressure drop. Difference in rejection of phenolic derivatives is consequence of interplay of surface charge and adsorption by alumina. Adsorption isotherm was fitted for different solutes and effects of pH were investigated. Catechol showed the maximum rejection 91% at solution pH 9. Addition of electrolyte reduced the rejection of solutes. Transmembrane pressure drop has insignificant effects on solute rejection. Competitive adsorption reduced the rejection of individual solute

2014-01-30

150

Adsorptive removal of phenolic compounds using cellulose acetate phthalate–alumina nanoparticle mixed matrix membrane  

Energy Technology Data Exchange (ETDEWEB)

Highlights: • Composite membrane of cellulose–acetate–phthalate and alumina nanoparticle is cast. • Surface charge of the membrane changes with nanoparticle concentration and pH. • Separation of phenolic compounds occurs due to adsorption. • The removal efficiency is maximum for 20% nanoparticle with 91% removal of catechol. • Transmembrane pressure drop has negligible effect on solute separation. -- Abstract: Mixed matrix membranes (MMMs) were prepared using alumina nanoparticles and cellulose acetate phthalate (CAP) by varying concentration of nanoparticles in the range of 10 to 25 wt%. The membranes were characterized by scanning electron micrograph, porosity, permeability, molecular weight cut off, contact angle, surface zeta potential, mechanical strength. Addition of nanoparticles increased the porosity, permeability of the membrane up to 20 wt% of alumina. pH at point of zero charge of the membrane was 5.4. Zeta potential of the membrane became more negative up to 20 wt% of nanoparticles. Adsorption of phenolic derivatives, catechol, paranitrophenol, phenol, orthochloro phenol, metanitrophenol, by MMMs were investigated. Variation of rejection and permeate flux profiles were studied for different solutes as a function of various operating conditions, namely, solution pH, solute concentration in feed and transmembrane pressure drop. Difference in rejection of phenolic derivatives is consequence of interplay of surface charge and adsorption by alumina. Adsorption isotherm was fitted for different solutes and effects of pH were investigated. Catechol showed the maximum rejection 91% at solution pH 9. Addition of electrolyte reduced the rejection of solutes. Transmembrane pressure drop has insignificant effects on solute rejection. Competitive adsorption reduced the rejection of individual solute.

Mukherjee, Raka; De, Sirshendu, E-mail: sde@che.iitkgp.ernet.in

2014-01-30

151

Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol  

Energy Technology Data Exchange (ETDEWEB)

Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of {sup 51}Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in {sup 51}Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal {sup 51}Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol.

Miller, M.J.; Zhang, x.J.; Gu, x.A.; Clark, D.A. (Department of Pediatrics, Louisiana State University School of Medicine, New Orleans (USA))

1991-07-01

152

Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol  

International Nuclear Information System (INIS)

Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of 51Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in 51Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal 51Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol

1991-01-01

153

Escherichia coli and Salmonella enterica Are Protected against Acetic Acid, but Not Hydrochloric Acid, by Hypertonicity?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Chapman et al. (B. Chapman, N. Jensen, T Ross, and M. B. Cole, Appl. Environ. Microbiol. 72:5165-5172, 2006) demonstrated that an increased NaCl concentration prolongs survival of Escherichia coli O157 SERL 2 in a broth model simulating the aqueous phase of a food dressing or sauce containing acetic acid. We examined the responses of five other E. coli strains and four Salmonella enterica strains to increasing concentrations of NaCl under conditions of lethal acidity and observed that the ave...

Chapman, B.; Ross, T.

2009-01-01

154

Removal of Organic Acids from Effluent via Freeze Crystallization.  

Directory of Open Access Journals (Sweden)

Full Text Available Freeze crystallization is an efficient separation process that can potentially be used in any application. Freeze crystallization is a high energy efficiency separation process that can be applied to a wide variety of industrial requirements. Although the vapor-liquid equilibrium is generally employed to separate the components of a solution, use of solid-liquid equilibrium should be considered – it may be cheaper. This paper describes a case study of recovery of acetic acid from effluent via freeze crystallization.Complete recovery of acetic acid from acetic acid-water solution by ordinary distillation is nearly impossible, because relative volatility of this mixture in the range of 1-30% of acetic acid in water is very close to one. Also, recovery of formic acid from its effluent stream by distillation is not economical viable as effluent stream of formic acid contains only 1-2% of formic acid. But the same separations are possible by freeze separation technique and it is found experimentally that large amount of acetic acid (about 70% and formic acid (about 90% can be recovered via freeze separation technique. Also it is found that the energy required for recovery of acetic acid is much lower (about 24 times than that of distillation.

Tarak C. Padhiyar

2013-05-01

155

Laboratory and field measurements to constrain atmospheric sources of acetic and formic acids  

Science.gov (United States)

Acetic and formic acids are the most abundant organic acids in the atmosphere. They play an important role in atmospheric aqueous chemistry as they can influence the acidity of precipitation, cloud droplets, and atmospheric aerosols. Sources of these acids are highly uncertain, but include secondary production from VOC oxidation, direct emissions, and possibly organic aerosol aging. Here we present measurements of formic and acetic acid, along with a suite of other gas and particle phase species, from a field study in St. Louis during summer 2013. Calibration procedures and results are discussed, and we interpret the ambient formic and acetic acid measurements in terms of patterns of variability and implied constraints on sources. Finally, we present results from oxidative aging experiments on both ambient and test organic aerosol designed to assess the importance of this mechanism as a source of gas-phase carboxylic acids.

Baasandorj, M.; Hu, L.; Mitroo, D.; Martinez, R.; Walker, M.; Williams, B. J.; Millet, D. B.

2013-12-01

156

Bioproduction of usnic acid from acetate by kaolinite immobilized cells of Cladonia substellata Vain.  

Directory of Open Access Journals (Sweden)

Full Text Available Cells of the lichen Cladonia substellata, immobilized in kaolinite and supplied with acetate, produce at room temperature large amounts of usnic acid which can be recovered from the washing solution.

Eugenia C. Pereira

1995-06-01

157

Complexing of zirconium and hafnium with halogen substituted of acetic acid in methanol solutions  

International Nuclear Information System (INIS)

The method of potentiometric titration was used to determine the reference stability constants for zirconium and hafnium complexes with fluoro-, chloro, iodo-, trifluoro-, and trichloro-acetic acid in methanol

1975-08-01

158

Metal chelate of uracil (4) methyl iminade acetic acid with different ? radioisotopes  

International Nuclear Information System (INIS)

The manufacture of metal chelates of the uracil (4) methyl iminade acetic acid on the laboratory scale is described. The uracil compounds with indium 113m and with technetium 99m were used for experiments on mice. (PW)

1977-06-24

159

Acetic acid and phenylquinone writhing test: a critical study in mice.  

Science.gov (United States)

Studies were planned to establish the dose-effect relationship with both acetic acid and phenylquinone and to find out suitable concentrations for these two chemicals for pre- and post screening. The LD50 of acetic acid and phenylquinone were found to be 3.16% and 0.23%, respectively. Based on the studies conducted, the prescreening and postscreening concentrations of 0.5% is recommended for acetic acid, while for phenylquinone, prescreening concentration of 0.005% and postscreening concentration of 0.02% is advocated. Using this criterion in the acetic acid writhing test, analgin was the most potent analgesic while aspirin was the least. However, suprofen was most potent and paracetamol least among analgesics employed against phenylquinone induced writhing. PMID:6668969

Singh, P P; Junnarkar, A Y; Rao, C S; Varma, R K; Shridhar, D R

1983-11-01

160

IMPROVED PROCESSES TO REMOVE NAPHTHENIC ACIDS  

Energy Technology Data Exchange (ETDEWEB)

In the second year of this project, we continued our effort to develop low temperature decarboxylation catalysts and investigate the behavior of these catalysts at different reaction conditions. We conducted a large number of dynamic measurements with crude oil and model compounds to obtain the information at different reaction stages, which was scheduled as the Task2 in our work plan. We developed a novel adsorption method to remove naphthenic acid from crude oil using naturally occurring materials such as clays. Our results show promise as an industrial application. The theoretical modeling proposed several possible reaction pathways and predicted the reactivity depending on the catalysts employed. From all of these studies, we obtained more comprehensive understanding about catalytic decarboxylation and oil upgrading based on the naphthenic acid removal concept.

Aihua Zhang; Qisheng Ma; Kangshi Wang, William A. Goddard, Yongchun Tang

2005-05-05

 
 
 
 
161

Removal of fluoride from aqueous nitric acid  

International Nuclear Information System (INIS)

Several methods for removing fluoride from aqueous nitric acid were investigated and compared with the frequently used aluminum nitrate-calcium nitrate (Ca"2"+-Al"3"+) chemical trap-distillation system. Zirconium oxynitrate solutions were found to be superior in preventing volatilization of fluoride during distillation of the nitric acid, producing decontamination factors (DFs) on the order of 2 x 10"3 (vs approx. 500 for the Ca"2"+-Al"3"+ system). Several other metal nitrate systems were tested, but they were less effective. Alumina and zirconia columns proved highly effective in removing HF from HF-HNO_3 vapors distilled through the columns; fluoride DFs on the order of 10"6 and 10"4, respectively, were obtained. A silica gel column was very effective in adsorbing HF from HF-HNO_3 solutions, producing a fluoride DF of approx. 10"4

1981-01-01

162

Complexation of chitosan with acetic acid according to Fourier transform Raman spectroscopy data  

Science.gov (United States)

The results of the interaction between the protonated chitosan (CHI) macromolecule and the acetate ion in dilute acetic acid solutions were studied by Fourier transform Raman spectroscopy and quantum-chemical modeling. The complexation of CHI with the acetate ion showed itself as the 934 cm-1 band in the Raman spectrum, which suggests the formation of [CHI+ · CH3COO-] type ion pairs. It was concluded that a comparative analysis of the integrated intensities of the Raman bands in the range 880-940 cm-1 makes it possible to judge about the relative content of hydrated acetate ions, CHI macromolecules of the [CHI+ · CH3COO-] complex, and acetic acid molecules not involved in CHI protonation.

Mikhailov, G. P.; Tuchkov, S. V.; Lazarev, V. V.; Kulish, E. I.

2014-06-01

163

Preparation of 13C-labeled ceramide by acetic acid bacteria and its incorporation in mice  

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We prepared 2-hydroxypalmitoyl-sphinganine (dihydroceramide) labeled with a stable isotope by culturing acetic acid bacteria with 13C-labeled acetic acid. The GC/MS spectrum of the trimethylsilyl derivative of 13C-labeled dihydroceramide gave molecular ions with an increased mass of 12–17 Da over that of nonlabeled dihydroceramide. The fragment ions derived from both sphinganine base and 2-hydroxypalmitate were confirmed to be labeled with the stable isotope in the spectrum. Therefore, 13C-...

Fukami, Hiroyuki; Tachimoto, Hideki; Kishi, Mikiya; Kaga, Takayuki; Waki, Hatsue; Iwamoto, Machiko; Tanaka, Yasukazu

2010-01-01

164

Synthesis and antioxidant evaluation of novel indole-3-acetic acid analogues  

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Indole-3-acetic acid (1) on reaction with thionyl chloride, afforded 2-(1H-indol-3-yl)acetyl chloride (2), which was further treated with aniline and various substituted anilines through base condensation reaction to obtain respected indole-3-acetic acid derivatives (3-9). The structures of all new compounds were elucidated by elemental analysis, Ma...

Nagaraja Naik; Honnaiah Vijay Kumar; Salakatte Thammaiah Harini

2011-01-01

165

Growing and laying performance of Japanese quail fed diet supplemented with different concentrations of acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available In order to evaluate the effect of acetic acid on growing and laying performance of Japanese Quail (JQ, 180 15-day-old JQ were divided into 4 groups. During the growing (15-42 days of age and laying (43-84 days of age periods, the groups fed the same basal diets supplemented with 0, 1.5, 3 and 6% of acetic acid. Each diet was fed to five replicates of 9 JQ (3 males:6 females during the growing period. During the laying period, 128 birds were housed in 32 cages (4 birds per cage, 1 male and 3 females, 8 replicates per treatment. Birds were housed in wire cages (46L×43W×20H cm in an open room. Acetic acid supplementation at 3% in the diets significantly increased the growth and laying rate and the Haugh unit score. The liver percentage significantly decreased with acetic acid at 6%. Acetic acid at 3% significantly increased hemoglobin concentrations at 6 weeks of age and increased weight of day old chicks hatched. Acetic acid affected the immune system as manifested by an excess of cellular reactions in the intestine as well as lymphoid hyperplasia in the spleen tissue. Degenerative changes in the covering epithelium of the intestinal villi were noted at the 6% concentration of acetic acid. Hepatocyte vacuolation and fatty changes were also observed at this concentration of treatment. In conclusion, 3% acetic acid may be used as a feed supplement for JQ during the growing and laying period to improve the productive performance.

Mohammed A. Al-Harthi

2013-04-01

166

Influence of acetic acid on the process of stain porous silicon formation at oxidant insufficiency  

International Nuclear Information System (INIS)

The influence of acetic acid on the process of stain porous silicon formation at oxidant insufficiency has been investigated. The process of porous formation has been estimated to be appreciably changed in concentration of acetic acid above 5 percent. This resulted in improvement of both reproducibility and lateral homogeneity of nanoporous silicon films. All obtained samples exhibit intensive photoluminescence in visible spectra at room temperature

2010-12-01

167

Synthesis of 14C-labeled halogen substituted indole-3-acetic acids  

International Nuclear Information System (INIS)

A general method for microscale synthesis of 14C-labeled indole-3-acetic acids with halogen substitutions in the benzene ring is described. The method utilizes halogen substituted phenylhydrazines reacted with [14C]-2-oxoglutarate to generate the halogenated indole-3-acetic acid. 3-Chlorophenyl-hydrazine yielded a mixture of the 4 and 6 chloro compounds that was resolved by C18-reverse phase high performance liquid chromatography. (author)

1985-01-01

168

Dissimilation of carbon monoxide to acetic acid by glucose-limited cultures of Clostridium thermoaceticum  

International Nuclear Information System (INIS)

Clostridium thermoaceticum was cultivated in glucose-limited media, and the dissimilation of CO to acetic acid was evaluated. The authors found that cultures catalyzed the rapid dissimilation of CO to acetic acid and CO_2, with the stoichiometry obtained for conversion approximating that predicted from the following reaction: 4CO + 2H_2O ? CH_3CO_2H + 2CO_2. Growing cultures formed approximately 50 mmol (3 g) of CO-derived acetic acid per liter of culture, with the rate of maximal consumption approximating 9.1 mmol of CO consumed/h per liter of culture. In contrast, resting cells were found not to dissimilate CO to acetic acid. "1"4CO was incorporated, with equal distribution between the carboxyl and methyl carbons of acetic acid when the initial cultivation gas phase was 100% CO whereas "1"4CO_2 preferentially entered the carboxyl carbon when the initial gas phase was 100% CO_2. Significantly, in the presence of saturating levels of CO, "1"4CO_2 preferentially entered the methyl carbon, whereas saturating levels of CO_2 yielded "1"4CO-derived labeling predominantly in the carboxyl carbon. These findings are discussed in relation to the path of carbon flow to acetic acid

1985-01-01

169

Recovery of arabinan in acetic acid-catalyzed hydrothermal pretreatment on corn stover  

DEFF Research Database (Denmark)

Acetic acid-catalyzed hydrothermal pretreatment was done on corn stover under 195 °C, 15 min with the acetic acid ranging from 5 Ã? 10â??3 to 0.2 g gâ??1 corn stover. After pretreatment, the water-insoluble solids (WISs) and liquors were collected respectively. Arabinan recoveries from both WIS and liquors were investigated. The results indicate that there was no detectable arabinan left in the WIS when the acetic acid of 0.1 and 0.2 g gâ??1 corn stover were used in the pretreatment. The arabinan contents in the other WISs were not more than 10%. However, the arabinan found in the liquors was not covering the amount of arabinan released from the raw corn stover. For the arabinan recovery from liquor fractions, the highest of 43.57% was obtained by the pretreatment of acetic acid of 0.01 g gâ??1 of corn stover and the lowest was only 26.77% when the acetic acid of 0.2 g gâ??1 corn stover was used. As far as the total arabinan recovery, the pretreatment with acetic acid at 0.01 g gâ??1 raw corn stover yielded the highest and it was 52.16%. This meant that almost half of the arabinose was degraded during the pretreatment process.

Xu, Jian; Hedegaard, Mette Christina

2009-01-01

170

Efficient ammonium removal from aquatic environments by Acinetobacter calcoaceticus STB1 immobilized on an electrospun cellulose acetate nanofibrous web  

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A novel biocomposite material was developed by immobilizing an ammonia-oxidizing bacterial strain, Acinetobacter calcoaceticus STB1, on an electrospun porous cellulose acetate (CA) nanofibrous web. Ammonium removal characteristics of the STB1 immobilized CA nanofibrous web were determined at varying initial ammonium concentrations, and removal rates of 100%, 98.5% and 72% were observed within 48 h for 50 mg L-1, 100 mg L-1 and 200 mg L-1 samples, respectively. Most of the ammonia is inferred ...

2013-01-01

171

The fraction of cells that resume growth after acetic acid addition is a strain-dependent parameter of acetic acid tolerance in Saccharomyces cerevisiae.  

Science.gov (United States)

High acetic acid tolerance of Saccharomyces cerevisiae is a relevant phenotype in industrial biotechnology when using lignocellulosic hydrolysates as feedstock. A screening of 38 S. cerevisiae strains for tolerance to acetic acid revealed considerable differences, particularly with regard to the duration of the latency phase. To understand how this phenotype is quantitatively manifested, four strains exhibiting significant differences were studied in more detail. Our data show that the duration of the latency phase is primarily determined by the fraction of cells within the population that resume growth. Only this fraction contributed to the exponential growth observed after the latency phase, while all other cells persisted in a viable but non-proliferating state. A remarkable variation in the size of the fraction was observed among the tested strains differing by several orders of magnitude. In fact, only 11 out of 10(7)  cells of the industrial bioethanol production strain Ethanol Red resumed growth after exposure to 157 mM acetic acid at pH 4.5, while this fraction was 3.6 × 10(6) (out of 10(7)  cells) in the highly acetic acid tolerant isolate ATCC 96581. These strain-specific differences are genetically determined and represent a valuable starting point to identify genetic targets for future strain improvement. PMID:24645649

Swinnen, Steve; Fernández-Niño, Miguel; González-Ramos, Daniel; van Maris, Antonius J A; Nevoigt, Elke

2014-06-01

172

Effects of the use of acetic acid as the conservant in lucerne ensiling  

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Full Text Available The influence of acetic acid as the chemical conservant in three doses (4, 6 8 g/kg green mass on the intensity of fermentation and proteolysis in lucerne silage was investigated. On the basis of chemical analysis, it was found that with the increase of conservant dose the pH value decreased aminogenesis and nitrogen solubility was limited. In silages treated the absolute and relative domination of acetic acid was found in total acid content. The increase of free and bonded acetic acid was discovered with the increase of conservant dose. Free butyric acid was not detected, while bonded butyric acid was present in negligible concentration, without effect on silage quality. Compared to control silage (III quality class according to DLG and Zelter method, a significant increase of acetic acid in silages resulted in the decline of their quality, and they were ranked as not useful (V quality class according to DLG method, or on the margin of usefulness (IV quality class according to Zelter method. In spite of some foreign references, domestic experiences show that acetic acid is not an effective conservant and it is not recommended for that use for lucerne that is not simple to ensile.

?or?evi? Nenad

2004-01-01

173

IMPROVED PROCESSES TO REMOVE NAPHTHENIC ACIDS  

Energy Technology Data Exchange (ETDEWEB)

In the first year of this project, we have established our experimental and theoretical methodologies for studies of the catalytic decarboxylation process. We have developed both glass and stainless steel micro batch type reactors for the fast screening of various catalysts with reaction substrates of model carboxylic acid compounds and crude oil samples. We also developed novel product analysis methods such as GC analyses for organic acids and gaseous products; and TAN measurements for crude oil. Our research revealed the effectiveness of several solid catalysts such as NA-Cat-1 and NA-Cat-2 for the catalytic decarboxylation of model compounds; and NA-Cat-5{approx}NA-Cat-9 for the acid removal from crude oil. Our theoretical calculations propose a three-step concerted oxidative decarboxylation mechanism for the NA-Cat-1 catalyst.

Aihua Zhang; Qisheng Ma; William A. Goddard; Yongchun Tang

2004-04-28

174

Synthesis and in vitro transdermal penetration enhancing activity of lactam N-acetic acid esters.  

Science.gov (United States)

A homologous series of N-acetic acid esters of 2-pyrrolidinone and 2-piperidinone has been prepared and evaluated for its ability to enhance the skin content and flux of hydrocortisone 21-acetate in hairless mouse skin in vitro. Enhancement ratios (ER) were determined for flux (J), 24-hour diffusion cell receptor cell concentrations (Q24), and 24-h full-thickness mouse skin steroid content (SC) and compared to control values (no enhancer present). In addition, in an attempt to abrogate toxicity, these dermal penetration enhancers were designed to have the potential for biodegradation by dermal esterases. 2-Oxopyrrolidine-alpha acetic acid dodecyl ester (5) showed the highest enhancement ratios for J (ER 67.33) and Q24 (ER 180.66). 2-Oxopiperidine-alpha-acetic acid decyl ester (10) showed a high Q24 (ER 162.07) but a lower J (ER 12.67). 2-Oxopyrrolidine-alpha-acetic acid decyl ester (3) showed the highest enhancement ratio for SC (ER 8.7). The ER Q24 for 3, 5 and 10, as well as other lactam N-acetic acid esters in this work, were significantly higher than the ER found using Azone as enhancer. PMID:8683439

Michniak, B B; Player, M R; Sowell, J W

1996-02-01

175

Thermal decarboxylation of acetic acid: Implications for origin of natural gas  

Science.gov (United States)

Laboratory experiments on the thermal decarboxylation of solutions of acetic acid at 200??C and 300??C were carried out in hydrothermal equipment allowing for on-line sampling of both the gas and liquid phases for chemical and stable-carbon-isotope analyses. The solutions had ambient pH values between 2.5 and 7.1; pH values and the concentrations of the various acetate species at the conditions of the experiments were computed using a chemical model. Results show that the concentrations of acetic acid, and not total acetate in solution, control the reaction rates which follow a first order equation based on decreasing concentrations of acetic acid with time. The decarboxylation rates at 200??C (1.81 ?? 10-8 per second) and 300??C (8.17 ?? 10-8 per second) and the extrapolated rates at lower temperatures are relatively high. The activation energy of decarboxylation is only 8.1 kcal/mole. These high decarboxylation rates, together with the distribution of short-chained aliphatic acid anions in formation waters, support the hypothesis that acid anions are precursors for an important portion of natural gas. Results of the ??13C values of CO2, CH4, and total acetate show a reasonably constant fractionation factor of about 20 permil between CO2 and CH4 at 300??C. The ??13C values of CO2 and CH4 are initially low and become higher as decarboxylation increases. ?? 1983.

Kharaka, Y. K.; Carothers, W. W.; Rosenbauer, R. J.

1983-01-01

176

Solvation model for the oxidation of methionine by imidazolium fluorochromate in aqueous acetic acid medium  

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Full Text Available The oxidation of methionine by imidazolium fluorochromate (IFC were studied, in the presence of chloroacetic acid, in water–acetic acid mixtures of varying molar compositions. The reaction is first order with respect to methionine, IFC and acid. The reaction rates were determined at different temperatures and the activation parameters were computed. The reaction rate increases with increasing mole fraction of acetic acid in the mixture and specific solvent–solvent–solute interactions were found to predominate (86 %. Asolvation model and a probable mechanism for the reaction are postulated.

BINCY JOHN

2006-01-01

177

Putative ABC Transporter Responsible for Acetic Acid Resistance in Acetobacter aceti  

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Two-dimensional gel electrophoretic analysis of the membrane fraction of Acetobacter aceti revealed the presence of several proteins that were produced in response to acetic acid. A 60-kDa protein, named AatA, which was mostly induced by acetic acid, was prepared; aatA was cloned on the basis of its NH2-terminal amino acid sequence. AatA, consisting of 591 amino acids and containing ATP-binding cassette (ABC) sequences and ABC signature sequences, belonged to the ABC transporter superfamily. ...

2006-01-01

178

Formic and acetic acid: Valence threshold photoelectron and photoionisation total ion yield studies  

International Nuclear Information System (INIS)

Highlights: ? High-resolution threshold photoelectron spectrum of formic acid. ? High-resolution total photo-ion yield spectrum of formic acid. ? High-resolution threshold photoelectron spectrum of acetic acid. ? High-resolution total photo-ion yield spectrum of acetic acid. -- Abstract: The carboxylic acids (formic and acetic) have been studied using threshold photoelectron (TPE) and total photoion yield (TPIY) spectroscopies; simultaneously obtained spectra of formic acid (HCOOH) were recorded over the entire valence ionisation region from 11–21 eV at a resolution of ?12 meV. Higher resolution spectra (?6 meV) were also obtained in the energy region of the lowest two cationic states. Analysis of the TPE spectrum in this energy range agreed very favorably with the best available conventional photoelectron (PE) spectrum of formic acid. Autoionising Rydberg structure was observed in the TPIY spectrum of formic acid and is attributed primarily to the presence of the npa? ? 8a? Rydberg series converging on to the 32A? ionic state of formic acid. Preliminary results, at a resolution of ?8 meV, were obtained for acetic acid (CH3COOH) over the onset of the ionisation energy region. The TPE spectrum was found to be very similar to the best published photoelectron spectrum, but no Rydberg structure was observed in the TPIY spectrum.

2012-09-01

179

Production of carrier-free "1"8F-labeled acetic acid via a recoil labeling method  

International Nuclear Information System (INIS)

Via recoil activation, carrier-free "1"8F-labeled acetic acid can be produced by the irradiation of a mixture of glacial acetic acid and potassium fluoride. The labeling yield seems to be high enough to produce this compound with activity amounts suitable for nuclear medical investigation. Using a mixture of glacial acetic acid and freon-11, "1"8F-labeled acetic acid could be found. This system is assumed to be more applicable for the production of other "1"8F-labeled carboxylic acids. Under optimized irradiation conditions we expect to produce some mCi of labeled monofluoroacetic acid. (orig.)

1980-01-01

180

Acetic Acid Activates the AMP-Activated Protein Kinase Signaling Pathway to Regulate Lipid Metabolism in Bovine Hepatocytes  

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The effect of acetic acid on hepatic lipid metabolism in ruminants differs significantly from that in monogastric animals. Therefore, the aim of this study was to investigate the regulation mechanism of acetic acid on the hepatic lipid metabolism in dairy cows. The AMP-activated protein kinase (AMPK) signaling pathway plays a key role in regulating hepatic lipid metabolism. In vitro, bovine hepatocytes were cultured and treated with different concentrations of sodium acetate (neutralized acet...

2013-01-01

 
 
 
 
181

Cyclodextrin-grafted electrospun cellulose acetate nanofibers via “Click” reaction for removal of phenanthrene  

Science.gov (United States)

Beta-cyclodextrin (?-CD) functionalized cellulose acetate (CA) nanofibers have been successfully prepared by combining electrospinning and “click” reaction. Initially, ?-CD and electrospun CA nanofibers were modified so as to be azide-?-CD and propargyl-terminated CA nanofibers, respectively. Then, “click” reaction was performed between modified CD molecules and CA nanofibers to obtain permanent grafting of CDs onto nanofibers surface. It was observed from the SEM image that, while CA nanofibers have smooth surface, there were some irregularities and roughness at nanofibers morphology after the modification. Yet, the fibrous structure was still protected. ATR-FTIR and XPS revealed that, CD molecules were successfully grafted onto surface of CA nanofibers. The adsorption capacity of ?-CD-functionalized CA (CA-CD) nanofibers was also determined by removing phenanthrene (polycyclic aromatic hydrocarbons, PAH) from its aqueous solution. Our results indicate that CA-CD nanofibers have potential to be used as molecular filters for the purpose of water purification and waste water treatment by integrating the high surface area of nanofibers with inclusion complexation property of CD molecules.

Celebioglu, Asli; Demirci, Serkan; Uyar, Tamer

2014-06-01

182

Ionic parachor and its application in acetic acid ionic liquid homologue 1-alkyl-3-methylimidazolium acetate {[C(n)mim][OAc](n = 2,3,4,5,6)}.  

Science.gov (United States)

Five acetic acid ionic liquids (AcAILs) [C(n)mim][OAc](n = 2,3,4,5,6) (1-alkyl-3-methylimidazolium acetate) were prepared by the neutralization method and characterized by (1)HNMR spectroscopy and differential scanning calorimetry (DSC). The values of their density and surface tension were measured at 298.15 ± 0.05 K. Since the AcAILs can strongly form hydrogen bonds with water, the small amounts of water are difficult to remove from the AcAILs by common methods. In order to eliminate the effect of the trace water, the standard addition method (SAM) was applied to these measurements. As a new concept, ionic parachor was put forward. [OAc](-) was seen as a reference ion, and its individual value of ionic parachor was determined in terms of two extrathermodynamic assumptions. Then, the values of ionic parachors of a number of anions, [NTf(2)](-), [Ala](-), [AlCl(4)](-), and [GaCl(4)](-), were obtained by using the value of the ionic parachor of the reference ion; the parachor and surface tension of the investigated ionic liquids in literature were estimated. In comparison, the estimated values correlate quite well with their matching experimental values. PMID:21978307

Guan, Wei; Ma, Xiao-Xue; Li, Long; Tong, Jing; Fang, Da-Wei; Yang, Jia-Zhen

2011-11-10

183

Primary and secondary reduction products in irradiated acetic, monofluoroacetic and glycolic acid single crystal  

International Nuclear Information System (INIS)

Single crystals of acetic acid, monofluoroacetic acid, and glycolic acid have been irradiated at low temperature and investigated with ESR. The main purpose of the work was to obtain data for the structure and the reactions of the primary reduction products, i.e. the molecular anions. The anions of acetic acid and glycolic acid are stable at 77 K. The monofluoroacetic acid anion could not be observed even at 3 K, but a decay product tentatively assigned to the F-...CH2COOH adduct was detected. The glycolic acid anion decomposes by elimination of water to CH2COOH radical. The radical products CFH2 and C(OH)H2 were observed in monofluoroacetic and glycolic acid, respectively. They are probably formed by decomposition of the molecular cations. (author)

1986-01-01

184

THIOGLYCOLIC ACID ESTERIFIED IN TO RICE STRAW FOR REMOVING LEAD FROM AQUEOUS SOLUTION  

Directory of Open Access Journals (Sweden)

Full Text Available Thiol rice straw (TRS was prepared by esterifying thioglycolic acid onto rice straw in the medium of acetic anhydride and acetic acid with sulfuric acid as catalyst. The sorption of lead (Pb on TRS from aqueous solution was subsequently investigated. The batch experiments showed that Pb removal was dependent on initial pH, sorbent dose, Pb concentration, contact time, and temperature. The maximum value of Pb removal appeared at pH 5. For 100 mg/L of Pb solution, a removal ratio of greater than 98% could be achieved with 2.0 g/L or more of TRS. The isothermal data of Pb sorption conformed well to the Langmuir model, and the maximum sorption capacity (Qm of TRS for Pb was 104.17 mg/g. The equilibrium of Pb removal was reached within 120 min. The Pb removal process could be described by the pseudo-first-order kinetic model. The thermodynamic study indicated that the Pb removal process was spontaneous and endothermic.

R. Gong

2011-09-01

185

Mixed metal zinc (II)-molybdenum (VI) peroxo complexes containing some amino acids and acetic acid  

International Nuclear Information System (INIS)

A facile synthesis of the title complexes which involve glycylglycine (Gg) glycine (Gly) and acetic acid (HAc) as ligands is reported. Reaction of equimolar mixtures of zinc and molybdic acid (MoO3.H2O) with Gg, or Gly or Ac, in excess hydrogen peroxide (H2O2) at ambient conditions, results in the formation of novel mixed metal complexes having the general formula, [Zn, Mo(O)2(O22-)(L)2(H2O)2], (L = Gg- or Gly- or Ac-). These new complexes have been characterised by elemental and thermogravimetric analyses, IR and electronic spectra. It is of interest to note that while heteronuclear peroxo complexes are quickly formed, the corresponding homonuclear Zn complexes could not be obtained. (author)

1997-06-01

186

N-chlorophthalimide as a new oxidant for direct titrations in aqueous acetic acid medium.  

Science.gov (United States)

A stable new oxidimetric titrant, N-chlorophthalimide in anhydrous acetic acid, is proposed for direct titrations of a variety of simple and complex reductants such as As(III), Sb(III), Fe(II), ferrocyanide, iodide, ascorbic acid, hydroquinone, hydrazine, phenylhydrazine, benzhydrazide, isonicotinic acid hydrazide, semicarbazide, thiourea, aniline, phenol, oxine and its metal complexes, and anthranilic acid and its metal complexes. PMID:18963951

Jayasree, N; Indrasenan, P

1985-11-01

187

A PreliminaryReport on the Mechanism of the Decomposition ofDiacetyl Peroxide in Acetic Acid  

Energy Technology Data Exchange (ETDEWEB)

The decomposition of diacetyl peroxide in acetic acid-2-C{sup 14} has been studied, The activity of the products in general confirmed the mechanism of the reaction as proposed by Kharasch and Gladstone, The presence and distribution of activity in the methyl acetate produced in this reaction is not explained by the previously proposed mechanism. There was no appreciable exchange of acetic acid and diacetyl peroxide under the conditions of the reaction. Essentially no exchange of methyl acetate and acetic acid was observed when those reagents mere heated at 100 for five hours.

Fry, A.J.; Tolbert, B.M.; Calvin, Melvin

1949-12-29

188

Cataluminescence sensor for gaseous acetic acid using a thin film of In2O3  

International Nuclear Information System (INIS)

We report on a cataluminescence sensor for the determination of gaseous acetic acid. It is based on a 60-nm thick sol-gel film of In2O3 on a ceramic support. SEM, XPS and surface profiling were applied for its characterization. It is found that aluminum ions of the ceramic substrate penetrate into the film and produce a synergetic catalytic effect. The sensor displays high sensitivity and specificity for acetic acid, a low detection limit, a wide linear range and a fast response. No (or only very low) interference was observed by formic acid, ammonia, acrolein, benzene, formaldehyde, ethanol, and acetaldehyde. The sensor was successfully applied to the determination of acetic acid in spiked air samples. We also discuss a conceivable mechanism (based on the reaction products) for the cataluminescence resulting from the oxidation reaction on the surface of the sensor film. (author)

2012-02-01

189

Large prebiotic molecules in space: photo-physics of acetic acid and its isomers  

CERN Document Server

An increasing number of large molecules have been positively identified in space. Many of these molecules are of biological interest and thus provide insight into prebiotic organic chemistry in the protoplanetary nebula. Among these molecules, acetic acid is of particular importance due to its structural proximity to glycine, the simplest amino acid. We compute electronic and vibrational properties of acetic acid and its isomers, methyl formate and glycolaldehyde, using density functional theory. From computed photo-absorption cross-sections, we obtain the corresponding photo-absorption rates for solar radiation at 1 AU and find them in good agreement with previous estimates. We also discuss glycolaldehyde diffuse emission in Sgr B2(N), as opposite to emissions from methyl formate and acetic acid that appear to be concentrate in the compact region Sgr B2(N-LMH).

Puletti, Fabrizio; Mulas, Giacomo; Cecchi-Pestellini, Cesare

2009-01-01

190

Glacial acetic acid as an efficient catalyst for simple synthesis of dindolylmethanes  

Directory of Open Access Journals (Sweden)

Full Text Available Glacial acetic acid as a protic acid was employed as a catalyst in a solvent free condition for facile preparation of di(indolylmethanes (DIMs via one-pot condensation of indole with aryl or heteroaryl aldehydes. Various aryl and heteroaryl aldehydes were efficiently converted to the corresponding di(indolylmethanes (1a-p in high yields. The described novel synthetic method proposes several advantages of safety, mild condition, short reaction times, high yields, simplicity and the inexpensively glacial acetic acid compared to other catalysts.

Mardia El-Sayed

2014-01-01

191

Effect of fluorophenylalanine on indole-3-acetic acid levels in Aveaa coleoptiles  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of the amino acid analogue D,L-p-fluorophenylalanine on indole-3-acetic acid levels in Avena has been examined. Previous studies have established that D,L-p-fluorophenylalanine promotes elongation, lowers phenolic levels and depresses auxin oxidase activity of etiolated Avena coleoptiles. This study employs an enzyme immunoassay to measure endogenous indole-3-acetic acid concentrations in coleoptile apices. These data demonstrate that treatment of Avena coleoptiles with D,L-p-fluorophenylalanine results in altered auxin levels and help clarify the mechanism of D,L-p-fluorophenylalanine action in Avena

Andrew B. Maksymowych

1988-12-01

192

Selectivity of colour reactions between elements and organic reagents in organo-aqueous acetic acid media  

International Nuclear Information System (INIS)

Reasons, responsible for selectivity of photometric reactions in organo-aqueous acetic acid media, have been studied taking aluminium, gallium, and indium reactions as examples. Solution-and paper electrophoresis as well as distribution chromatography were used to examine the state of the elements in various media, including those for most selective determination of aluminium in the presence of gallium and indium. A high selectivity is due to the formation of an electrically neutral species of aluminium. And chloride complexes of gallium and indium in organo-aqueous acetic acid media. Coloured ternary complexes of aluminium with organic reagents and phosphoric acid are formed in the presence of the latter

1982-10-01

193

Extraction equilibria of acetic and propionic acids from dilute aqueous solution by several solvents  

Energy Technology Data Exchange (ETDEWEB)

Extraction equilibria of acetic acid and propionic acid with hexane solutions of trioctyl amine, trioctyl phosphine oxide, and tributyl phosphate were studied. The species formed in the systems were estimated, and the distribution coefficients and the equilibrium constants for these species were evaluated.s

Fahim, M.A. (Univ. of United Arab Emirates, Al-Ain (United Arab Emirates))

1992-10-01

194

Phase equilibrium modelling for mixtures with acetic acid using an association equation of state  

DEFF Research Database (Denmark)

Acetic acid is a very important compound in the chemical industry with applications both as solvent and intermediate in the production of, e.g., polyesters. The design of these processes requires knowledge of the phase equilibria of mixtures containing acetic acid and a wide variety of compounds over extended temperature and pressure ranges. From the scientific point of view, modeling of such equilibria is challenging because of the complex association and solvation phenomena present. In this work, a previously developed association equation of state (cubic-plus-association, CPA) is applied to a wide variety of mixtures containing acetic acid, including gas solubilities, cross-associating systems (with water and alcohols), and polar chemicals like acetone and esters. Vapor-liquid and liquid-liquid equilibria are considered for both binary and ternary mixtures. With the exception of a somewhat inferior performance for the water-acetic acid VLE, which does not seem to affect substantially the performance for the multicomponent systems studied, CPA performs satisfactorily in most cases, using a single interaction parameter over extensive temperature ranges. For accurate description of water-acetic acid, use of the Huron-Vidal mixing rule for the energy parameter of CPA can yield a satisfactory correlation at the cost of more interaction parameters.

Muro Sunè, Nuria; Kontogeorgis, Georgios

2008-01-01

195

Regeneration of basic sorbents used in the recovery of acetic acid from dilute aqueous solution  

Energy Technology Data Exchange (ETDEWEB)

The regeneration of basic sorbents used in the recovery of dilute aqueous acetic acid was explored. The regeneration methods studied were solvent leaching and vaporization. The resins used were weak base anion exchange resins, Dow Chemical Company's Dowex MWA-1 (tertiary amine resin) and Celanese Corporation's Aurorez (polybenzimidazole resin). The equilibrium between the aqueous acetic acid solution and the resins was measured in batch experiments. The composite isotherms calculated from these data wee comparable to those of other researchers. Methanol was used as the solvent to leach acetic acid from the resin. The equilibrium data from the batch experiments were used in the local-equilibrium theory of fixed-bed devices to model the desorption behavior of acetic acid in methanol. Both sorption and desorption equilibrium data were used in chemical complexation models to obtain sorption affinities and capacities of the resin for acetic acid. However, the amount of methanol needed to achieve a high degree of regeneration was too large to be economical. 15 refs., 25 figs., 3 tabs.

Ng, M.; King, C.J.

1988-10-01

196

The Comparison of Acetic Acid and Strontium Chloride Procedures for Extraction of Hemin  

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Full Text Available Background and objectives: Hemin is a porphyrin compound derived from hemoglobin, the precursor of other porphyrin hemoglobin derivatives and the raw material of Hematin. Since hemin is widely used in medicine, we decided primarily to synthesize this substance in Laboratory and to determine the best way of hemin extraction from untransfused and expired blood units. Materials and Methods: In the first method, Glacial acetic acid and sodium chloride were added to citrated blood and hemin crystals were extracted by means of cooling. Finally, the obtained product, by visible spectrophotometer and Infrared Spectrophotometer, was compared to standard samples. Fur thermore, citrated blood, citrated blood hemolysed by distilled water and citrated blood washed by normal saline were used comparatively as a raw material to produce Hemin. The second method was performed by adding Strontium, acetic acid and acetone to blood samples and then after precipitating Hemin crystals they were washed and dried with acetone. Results: The presence of functional groups in Hemin samples, analyzed by infrared Spectrophotometer, indicates the production of this compound. The results of visible Spectrophotometer in comparison with control samples and the results of samples weighting demonstrates high efficiency of extraction stages and the purity of obtained compound. Conclusion: The use of intact citrated blood produces more Hemin than the other kind of Citrated blood samples. Moreover, acetic acid with citrated blood, without any processing on blood, is the best way for Hemin production. Key words: strontium, Hemin, Blood, acetic acid, extractionKeywords: Key words: strontium, Hemin, Blood, acetic acid, extraction,

F Hadizadeh

2007-01-01

197

Corrosion and electrochemical behaviour of 316L stainless steel in acetic acid solutions  

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The corrosion and electrochemical behaviour of 316S11 stainless steel in acetic acid solutions typifying chemical process environments has been investigated. Acetic acid concentrations tested were in the range 70-90% and included addition of 1500 ppm Br{sup -} and 200 ppm Na{sup +}. Of key interest was the impact of Cl{sup -} ions, representing an uncontrolled excursion in system chemistry. Corrosion potential-time and electrochemical polarisation measurements were made for the different environments at 90 deg. C and the characteristics of the surface film formed at different stages of exposure analysed using X-ray photo-electron spectroscopy (XPS). The most distinctive feature of the results was the step increase in potential with exposure time in the 70% acetic acid solution, in the absence of Cl{sup -} ions, indicating a sharp transition from active corrosion to some degree of passivity. No such transition was observed in the 90% acetic acid solution. Addition of chloride to the 70% acetic acid solution after the step in potential resulted in a step decrease in potential once a critical level of chloride had been exceeded. If the chloride were present on initial immersion, the potential stayed relatively low and the steel remained active. XPS analysis suggested that local enrichment of Mo was important in initiating the passivation process but the precise details of the mechanism remain speculative.

Turnbull, Alan; Ryan, Mary; Willetts, Anthony; Zhou Shengqi

2003-05-01

198

Acetic Acid Detection Threshold in Synthetic Wine Samples of a Portable Electronic Nose  

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Full Text Available Wine quality is related to its intrinsic visual, taste, or aroma characteristics and is reflected in the price paid for that wine. One of the most important wine faults is the excessive concentration of acetic acid which can cause a wine to take on vinegar aromas and reduce its varietal character. Thereby it is very important for the wine industry to have methods, like electronic noses, for real-time monitoring the excessive concentration of acetic acid in wines. However, aroma characterization of alcoholic beverages with sensor array electronic noses is a difficult challenge due to the masking effect of ethanol. In this work, in order to detect the presence of acetic acid in synthetic wine samples (aqueous ethanol solution at 10% v/v we use a detection unit which consists of a commercial electronic nose and a HSS32 auto sampler, in combination with a neural network classifier (MLP. To find the characteristic vector representative of the sample that we want to classify, first we select the sensors, and the section of the sensors response curves, where the probability of detecting the presence of acetic acid will be higher, and then we apply Principal Component Analysis (PCA such that each sensor response curve is represented by the coefficients of its first principal components. Results show that the PEN3 electronic nose is able to detect and discriminate wine samples doped with acetic acid in concentrations equal or greater than 2 g/L.

Miguel Macías Macías

2012-12-01

199

ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF THE OXIDISED PRODUCT OF INDOLE-3- ACETIC ACID BY POTASSIUM BROMATE SCAVENGED AND UNSCAVENGED BY MERCURIC ACETATE  

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Full Text Available The oxidation of indole-3-acetic acid by potassium bromate in acetic acid medium was studied.  The oxidation of IAA was done in the presence and absence of the scavenger mercuric acetate. The final product was identified as 3-methylene oxindole by the IR and NMR spectral studies and then examined for biological activity. The antibacterial activity was carried out by agar diffusion method. The antifungal activity of the synthesised product was evaluated by agar diffusion method using potato dextrose agar.

Deepa D*, Chandramohan G, Chandralekha S and Sumathi P

2013-01-01

200

ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF THE OXIDISED PRODUCT OF INDOLE-3- ACETIC ACID BY POTASSIUM BROMATE SCAVENGED AND UNSCAVENGED BY MERCURIC ACETATE  

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Full Text Available The oxidation of indole-3-acetic acid by potassium bromate in acetic acid medium was studied.  The oxidation of IAA was done in the presence and absence of the scavenger mercuric acetate. The final product was identified as 3-methylene oxindole by the IR and NMR spectral studies and then examined for biological activity. The antibacterial activity was carried out by agar diffusion method. The antifungal activity of the synthesised product was evaluated by agar diffusion method using potato dextrose agar.

Deepa D*, Chandramohan G, Chandralekha S and Sumathi P

2013-02-01

 
 
 
 
201

Pitting Corrosion of Tin by Acetate Anion in Acidic Media  

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Full Text Available The corrosion behaviour of tin is studied in acetate buffer solutions (pH 4.5. The potentiodynamic anodic polarization curve in 0.1M acetate solution exhibits two anodic peaks A1 and A2 prior to the passive layer formation region which is followed by pitting corrosion. A1 and A2 are attributed to stannous and stannic species formation. The effect of scan rate on the potentiodynamic behaviour of tin in this solution was studied. It showed that the corrosion process in the potential range of peaks A1 and A2 is mass transport controlled. Pitting corrosion is confirmed by light microscope images. The negative going scans of the cyclic voltammograms show three cathodic peaks C1, C2 and C3. The potentiostatic current time transients, at different electrolyte concentrations and applied potentials (around the pitting potential involve three stages. The first stage, in which current decreases rapidly with time till reaching a minimum value im at the incubation time ti . The second and third stages, where current increases again linearly with time at two different slopes, are correlated to the pit nucleation and growth respectively. The nucleation rate (ti-1 was found to increase with increasing the electrolyte concentration and the anodic applied potential. The impedance spectra, at potentials of passive layer and pitting formations, exhibit a high frequency conductive semicircle and a low frequency inductive loop. The results showed a decrease in the electrode impedance as the applied potential approached the pitting potential.

Hamdy H. Hassan, Khalid Fahmy

2008-01-01

202

Parallel pathways for photocatalytic decomposition of acetic acid on TiO{sub 2}  

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Acetic acid decomposes photocatalytically on TiO{sub 2} at room temperature in an inert atmosphere through two parallel pathways. In one pathway, acetic acid decomposed to gas-phase CO{sub 2} and apparently forms hydrogen and methyl groups, which combine on the surface to form CH{sub 4}. In the other pathway, acetic acid extracts oxygen from the TiO{sub 2} lattice to form adsorbed H{sub 2}O and gas-phase CO{sub 2} and C{sub 2}H{sub 6}. The extracted oxygen is replenished by diffusion from the bulk in an inert atmosphere or by gas-phase O{sub 2}. The formation of CH{sub 4} and CO{sub 2} in the first pathway does not consume lattice oxygen. The first step in photocatalytic decomposition (PCD) of acetic acid appears to be dissociation of the O-H bond, producing surface acetates. However, molecularly adsorbed acetic acid reacts at the same rate and with the same selectivity as surface acetates. Only the {alpha}-carbon forms CO{sub 2} during PCD. When gas-phase O{sub 2} is present, adsorbed methyl groups oxidize before they are hydrogenated to CH{sub 4}. The oxidizing agent during photocatalytic oxidation (PCO) is different from that during PCD and is most likely adsorbed oxygen. Adsorbed oxygen reacts with acetic acid in a different pathway from the two reactions observed for PCD, so a Mars Van Krevlen mechanism for PCO appears unlikely. The TiO{sub 2} surface is not homogeneous and some surface sites are more active during both PCD and PCO. Co-adsorbed water increases the rate of CH{sub 4} formation, apparently by reacting with CH{sub 3(ads)} to form CH{sub 4}, but in contrast to adsorbed O{sub 2}, water does not react with acetic acid in a separate pathway that is different from those observed for PCD without water.

Muggli, D.S.; Falconer, J.L.

1999-10-01

203

The Effect of Curcumin (Active Substance of Turmeric)on the Acetic Acid-Induced Visceral Nociception in Rats  

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In the present study, the effect of chronic oral administration of curcumin in the presence or absence of morphine and noloxone was investigated on the visceral nociception induced by acetic acid in rats. Intraperitoneal injection of acetic acid (1 mL, 2%) produced contractions in the abdominal musculature (writhes). The latency time to the beginning of the first writhe was measured and the total number of writhes in the 1 h after acetic acid injection was counted. The latency time to the ...

Hossein Tajik; Esmaeal Tamaddonfard; Nasrin Hamzeh-Gooshchi

2008-01-01

204

Efficacy of renal artery embolization with 50 % acetic acid in rabbits, and pathologic findings  

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The purpose of this study is to evaluate the embolic effect and pathologic change in the kidney after infusion of 50 % acetic acid in the renal artery. Five kidneys were embolized with 50 % acetic mixed with saline (group A) and five were embolized with 50 % acetic acid mixed with contrast medium (group B). Four rabbits (2 from group A and 2 from group B) were sacrificed during the first day and the remaining six, 28 days after embolization. To determine the effect of embolization and pathologic findings, the groups were compared. Complete occlusion of the renal artery was observed in both groups; histologic findings indicating tubular necrosis and blood clots within the renal artery were noted one day after embolization. After four weeks, complete necrosis of the renal arterial wall and tubular cells had occurred. The procedures required for embolization were easier in group B because the extent of embolization could be controlled by fluoroscopy. At 50 % dilution after mixing with contrast medium, the embolic effect of acetic acid is perfect; because the embolic material is visualized the procedure was easier to control than embolization with alcohol, acetic acid can, therefore, be used as an effective embolic agent in renal artery embolization. (author). 19 refs., 3 figs.

Yi, Bum Ha; Oh, Joo Hyung; Yoon, Yup; Ko, Young Tae; Sung, Dong Wook; Choi, Dong Sik; Lee, Ju Hee [Kyunghee University Hospital, Seoul (Korea, Republic of)

1998-06-01

205

Nickel adsorption onto carbon anode dust modified by acetic acid and KOH  

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Full Text Available Carbon anode dust (CAD is metallurgical waste material of aluminium production industry. The objective of this study was to convert carbon anode dust to acetic acid-modified and KOH-modified carbon adsorbat. Modified and unmodified carbon anode dust samples were characterized by SEM analysis. Pore volume, pore size and surface area were determined with BET method. The prepared carbons were evaluated for their adsorption capacity of nickel ions. The experimental data were analyzed by Freundlich and Langmuir isotherms. Changes in the surface morphology, surface area properties and obtained adsorption capacity indicate that acetic acid is a better modifier than KOH. Equilibrium results showed that acetic acid modification increased the CAD adsorption capacity for Ni (II more than KOH modification.

Štrkalj A.

2010-01-01

206

Acetic acid as an intervention strategy to decontaminate beef carcasses in mexican commercial slaughterhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Beef can be contaminated during the slaughter process, thus other methods, besides the traditional water washing, must be adopted to preserve meat safety. The objective of this study was to evaluate the effect of 2% acetic acid interventions on the reduction of indicator bacteria on beef carcasses a [...] t a commercial slaughterhouse in Mexico. Reduction was measured by the count of mesophilic aerobic bacteria (TPC), total coliform (TC), and fecal coliform (FC) (log CFU/ cm²). Among the different interventions tested, treatments combining acetic acid solution sprayed following carcass water washing had greater microbial reduction level. Acetic acid solution sprayed at low pressure and longer time (10-30 psi/ 60 s) reached higher TPC, TC, and FC reductions than that obtained under high pressure/ shorter time (1,700 psi/ 15 s; P

Reyes Carranza, Laura; Rubio Lozano, Maria Salud; Méndez Medina, Ruben Danilo; Rodarte, Maria Del Carmen Wacher; Núñez Espinosa, Jose Fernando; Velázquez Camacho, Bertha Lucila; Macedo, Renata Ernlund Freitas.

207

STUDY OF THE INTERACTIONS BETWEEN COPPER(II ACETATE MONOHYDRATE AND OROTIC ACID AND OROTATE LIGANDS  

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Full Text Available Different complexes by reacting copper(II acetate monohydrate with orotic acid and orotate as ligands were prepared. These compounds were characterized by elemental analysis, spectroscopy, and thermal analysis. It is suggested that in both compounds, the Cu2(acetate4 suffers the break of both acetate groups by a substitution of orotic or orotate ligands, increasing the Cu-Cu distance. It was corroborated by the magnetic moment values of 1.65 and 1.82 B.M for these compounds. The anion orotato(-1 coordinates through the carboxylic acid and the orotic acid by the oxygen from exocyclic C=O. Semiempirical PM3 calculations for both compounds were also carried out.

GLORIA V SEGUEL

2010-01-01

208

Protective effect of embelin against acetic acid induced ulcerative colitis in rats.  

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The aim of the present study is to evaluate the effect of embelin isolated from Embelia ribes on acetic acid induced colitis in rats. Experimental animals received embelin (25 and 50 mg/kg, p.o.) and sulfasalazine (100mg/kg, p.o.) for five consecutive days before induction of colitis by intra-rectal acetic acid (3% v/v) administration and the treatment continued up to 7 days. The colonic mucosal injury was assessed by clinical, macroscopic, biochemical and histopathological examinations. Embelin treatment significantly decreased clinical activity score, gross lesion score, percent affected area and wet colon weight when compared to acetic acid induced controls. The treatment also reduced significantly the colonic myeloperoxidase activity, lipid peroxides and serum lactate dehydrogenase and significantly increased the reduced glutathione. The histopathological studies also confirmed the foregoing findings. The protective effect may be due to its antioxidant and anti-inflammatory activities. PMID:21185828

Thippeswamy, Boreddy Shivanandappa; Mahendran, Sekar; Biradar, Mahantesh I; Raj, Pooja; Srivastava, Kamya; Badami, Shrishailappa; Veerapur, Veeresh Prabhakar

2011-03-01

209

Dual Antiplatelet Regime Versus Acetyl-acetic Acid for Carotid Artery Stenting  

International Nuclear Information System (INIS)

Carotid artery stenting has been proposed as an option treatment of carotid artery stenosis. The aim of this single-institution study is to compare the dual-antiplatelet treatment and heparin combined with acetyl-acetic acid, in patients who underwent carotid artery stenting. We compared 2 groups of 50 patents each who underwent carotid artery stenting for primary atherosclerotic disease. Group A received heparin for 24 h combined with 325 mg acetyl-acetic acid and group B received 250 mg ticlopidine twice a day combined with 325 mg acetyl-acetic acid. Outcome measurements included 30-day bleeding and neurological complications and 30-day thrombosis/occlusion rates. The neurological complications were 16% in group A and 2% in group B (p 0.05). The 30-day thrombosis/occlusion rate was 2% in group A and 0% in group B (p > 0.05). Dual antiplatelet treatment is recommended in all patients undergoing carotid artery stenting

2006-08-01

210

Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid  

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Full Text Available Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications.

SergioGiannattasio

2013-02-01

211

1,2-Di-4-pyridylethane N,N?-dioxide–acetic acid (1/2  

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Full Text Available The title compound, C12H12N2O2·2C2H4O2, was prepared from 1,2-di-4-pyridylethane, acetic acid, and hydrogen peroxide. The 1,2-di-4-pyridylethane N,N?-dioxide molecule is located on an inversion center. ?–? stacking interactions between neighboring 1,2-di-4-pyridylethane N,N?-dioxide molecules are observed with a centroid–centroid distance of 3.613?Å, an interplanar distance of 3.317?Å, and a slippage of 1.433?Å. O—H...O hydrogen-bonding interactions between 1,2-di-4-pyridylethane N,N?-dioxide and acetic acid molecules result in distinct hydrogen-bonded units made of one N-oxide and two acetic acid molecules. These units are then linked into a three-dimensional network through weaker C—H...O hydrogen-bonding interactions.

Jacqueline M. Knaust

2009-12-01

212

STUDY OF THE INTERACTIONS BETWEEN COPPER(II) ACETATE MONOHYDRATE AND OROTIC ACID AND OROTATE LIGANDS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Different complexes by reacting copper(II) acetate monohydrate with orotic acid and orotate as ligands were prepared. These compounds were characterized by elemental analysis, spectroscopy, and thermal analysis. It is suggested that in both compounds, the Cu2(acetate)4 suffers the break of both acet [...] ate groups by a substitution of orotic or orotate ligands, increasing the Cu-Cu distance. It was corroborated by the magnetic moment values of 1.65 and 1.82 B.M for these compounds. The anion orotato(-1) coordinates through the carboxylic acid and the orotic acid by the oxygen from exocyclic C=O. Semiempirical PM3 calculations for both compounds were also carried out.

SEGUEL, GLORIA V; RIVAS, BERNABÉ L; PAREDES, CÉSAR.

213

[Determination of five halogenated acetic acids in water using ion chromatography].  

Science.gov (United States)

The five halogenated acetic acids (HAAs), monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), trichloro acetic acid (TCAA), monobromoacetic acid (MBAA), dibromoacetic acid (DBAA), were separated on an IonPac AS19 column specially designed for oxyhalides, and the separating conditions were optimized. DCAA and nitrite were separated by controlling the temperature. TCAA and sulfate were well separated rapidly by the concentration gradient of mobile phase. The interfering of carbonate (bicarbonate) was eliminated by the method of neutralization vacuum exhausting gas. The experimental results showed that the five HAAs, nitrite, bromide, nitrate, sulfate, etc. can be separated and detected simultaneously, and the detection limits of the DCAA and TCAA were 2.50 microg/L and 3.75 microg/L respectively, and the linearity ranges were from 10.0 to 2000.0 microg/L with the correlation coefficients of 0.999. The method is satisfied for the determination of drinking water. PMID:18438039

Gui, Jianye; Zhang, Lin

2008-01-01

214

Application of bipolar electrodialysis to E.coli fermentation for simultaneous acetate removal and pH control  

DEFF Research Database (Denmark)

The application of bipolar electrodialysis (BPED) for the simultaneous removal of inhibitory acetate and pH control during E. coli fermentation was investigated. A two cell pair electrodialysis module, consisting of cation exchange, anion exchange and bipolar membranes with working area of 100 cm2 each, was integrated with a standard 7 l stirred tank bioreactor. Results showed that BPED was beneficial in terms of in situ removal of inhibitory acetate and a reduction in the amount NH4OH used for pH control. In batch and fed-batch BPED fermentations, base additions were decreased by up to 50% in both cases compared to electrodialysis (ED) fermentations with pH controlled at 6.7 ± 0.1. Consequently, the final biomass (34.2 g DCW lâ??1) and recombinant protein (5.5 g lâ??1) concentrations obtained were increased by up to 37 and 20%, respectively.

Wong, M.; Woodley, John

2010-01-01

215

Preventive activity of ascorbic acid on lead acetate induced cerebellar damaged in adult Wistar rats  

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Full Text Available Among the environmental contaminants, lead is one of the most hazardous to living matter. In mammals, the main target is the central nervous system, particularly in the young. Ascorbic acid is an antioxidant which is a substance that may protect your cells against the effects of free radicals. This study investigated Experiment the protective effect of ascorbic acid on the cerebellum of adult Wistar rats following oral administration of different doses of Lead acetate. Thirty adult Wistar rats of average weight of 215g were used in this study. The animals were divided into five (5 groups of six animals per group and were administered different doses of lead acetate (60mg/kg bwt of 1/10th LD50 and 30mg/kg bwt of 1/20th of LD50 and ascorbic acid (4.3mg/kg bwt orally over a period of three (3 weeks.Group 1 (control was administered distilled water and Group 2 and 3 were administered 30mg/kg and 60mg/kg of Lead acetate respectively while Group 4 and 5 were given co-administration of 30mg/kg of Lead acetate 4.3mg/kg of ascorbic acid and 60gm/kg of Lead acetate 4.3mg/kg of ascorbic acid respectively. Histopathologically, Lead acetate induced cellular damage in the cerebellum of adult Wistar rats and it was also observed that ascorbic acid prevents or minimize lead-induced cellular damage in the cerebellum of adult Wistar rats.

Sunday Abraham Musa

2012-12-01

216

Removal of an anionic dye (Acid Blue 92) by coagulation-flocculation using chitosan.  

Science.gov (United States)

Chitosan (a biopolymer) is an aminopolysaccharide that can be used for the treatment of colored solutions by coagulation-flocculation (as an alternative to more conventional processes such as sorption). Acid Blue 92 (a sulfonic dye) was selected as a model dye for verifying chitosan's ability to treat textile wastewater. A preliminary experiment demonstrated that chitosan was more efficient at color removal in tap water than in demineralized water, and that a substantially lower concentration of chitosan could be used with tap water. Dye removal reached up to 99% under optimum concentration; i.e., in terms of the acidic solutions and the stoichiometric ratio between the amine groups of the biopolymer and the sulfonic groups in the dye. The flocs were recovered and the dye was efficiently removed using alkaline solutions (0.001-1 M NaOH solutions) and the biopolymer, re-dissolved in acetic acid solution, was reused in a further treatment cycle. PMID:19467769

Szygu?a, Agata; Guibal, Eric; Ariño Palacín, María; Ruiz, Montserrat; Sastre, Ana Maria

2009-07-01

217

Isolation and characterization of esters of indole-3-acetic acid from the liquid endosperm of the horse chestnut (Aesculus species)  

Science.gov (United States)

Esters of indole-3-acetic acid were extracted and purified from the liquid endosperm of immature fruits of various species of the horse chestnut (Aesculus parviflora, A. baumanni, A. pavia rubra, and A. pavia humulis). The liquid endosperm contained, at least 12 chromatographically distinct esters. One of these compounds was purified and characterized as an ester of indole-3-acetic acid and myo-inositol. A second compound was found to be an ester of indole-3-acetic acid and the disaccharide rutinose (glucosyl-rhamnose). A third compound was partially characterized as an ester of indole-3-acetic acid and a desoxyaminohexose.

Domagalski, W.; Schulze, A.; Bandurski, R. S.

1987-01-01

218

Determination of 4-Chloroindole-3-Acetic Acid Methyl Ester in Lathyrus Vicia and Pisum by Gas Chromatography - Mass Spectrometry  

DEFF Research Database (Denmark)

4-Chloroindole-3-acetic acid methyl ester was identified unequivocally in Lathyrus latifolius L., Vicia faba L. and Pisum sativum L. by thin layer chromatography, gas chromatography and mass spectrometry. The gas chromatographic system was able to separate underivatized chloroindole-3-acetic acid methyl ester isomers. The quantitative determination of 4-chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography â?? mass spectrometry using deuterium labelled 4-chloro-indole-3-acetic acid methyl ester as an internal standard. P. sativum contained approximately 25 mg kg-1, V. faba 1â??2 mg kg-1 and L. latifolius 2 mg kg-1 dry weight.

Engvild, Kjeld Christensen; Egsgaard, Helge

1980-01-01

219

Anticoccidial effects of acetic acid on performance and pathogenic parameters in broiler chickens challenged with Eimeria tenella  

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Full Text Available The objective of the present study was to evaluate the anticoccidial effect of the different concentrations of the acetic acid in the broiler chickens in comparison with the amprolium anticoccidial. A total of 198 chicks were placed 11 per pen with three pens per treatment. The different concentrations (1%, 2% and 3% of acetic acid and amproilum (at the dose rate of 125ppm were given to the experimental groups in drinking water from 10-19th days of age. One group was kept as infected non medicated control and one as non infected non medicated control. All the groups were inoculated orally with 75,000 sporulated oocysts at the 12th day of age except non infected non medicated control. Anticoccidial effect was evaluated on the basis of performance (weight gain, feed conversion ratio and pathogenic (oocyst score, lesion score and mortality %age parameters. Among acetic acid medicated groups, the maximum anticoccidial effect was seen in the group medicated with 3% acetic acid followed by 2% and 1% acetic acid medicated groups. Amprolium and 3% acetic acid were almost equivalent in suppressing the negative performance and pathogenic effects associated with coccidiosis (Eimeria tenella challenge. In summary, acetic acid has the potential to be used as alternative to chemotherapeutic drugs for Eimeria tenella control. Concentration-dependent anticoccidial effect of acetic acid suggests that further studies should be carried out to determine the possible maximum safe levels of acetic acid with least toxic effects to be used as anticoccidial.

Rao Z. Abbas

2011-02-01

220

Use of acetic and citric acids to control Salmonella Typhimurium in tahini (sesame paste).  

Science.gov (United States)

Since tahini and its products have been linked to Salmonella illness outbreaks and product recalls in recent years, this study assessed the ability of Salmonella Typhimurium to survive or grow in commercial tahini and when hydrated (10% w/v in water), treated with 0.1%-0.5% acetic or citric acids, and stored at 37, 21 and 10 °C for 28 d. S. Typhimurium survived in commercial tahini up to 28 d but was reduced in numbers from 1.7 to 3.3 log10 CFU/ml. However, in the moist or hydrated tahini, significant growth of S. Typhimurium occurred at the tested temperatures. Acetic and citric acids at ?0.5% reduced S. Typhimurium by 2.7-4.8 log10 CFU/ml and 2.5-3.8 log10 CFU/ml, respectively, in commercial tahini at 28 d. In hydrated tahini the organic acids were more effective. S. Typhimurium cells were not detected in the presence of 0.5% acetic acid after 7 d or with 0.5% citric acid after 21 d at the tested temperatures. The ability of S. Typhimurium to grow or survive in commercial tahini and products containing hydrated tahini may contribute to salmonellosis outbreaks; however, use of acetic and citric acids in ready-to-eat foods prepared from tahini can significantly minimize the risk associated with this pathogen. PMID:24929724

Al-Nabulsi, Anas A; Olaimat, Amin N; Osaili, Tareq M; Shaker, Reyad R; Zein Elabedeen, Noor; Jaradat, Ziad W; Abushelaibi, Aisha; Holley, Richard A

2014-09-01

 
 
 
 
221

Antimicrobial activity of an acetic and boric acid solution against Staphylococcus pseudintermedius  

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Incubation of 101 colony forming units/ml of Staphylococcus pseudintermedius in an undiluted, a 1:2 and a 1:4 diluted aqueous 2% acetic acid and 2% boric acid solution resulted in inactivation of the bacteria within 30, 60 and 120 minutes, respectively. This indicates that a combination of these acids might be useful for local treatment of S. pseudintermedius infections. Further clinical studies are necessary, however, to confirm these in vitro results.

Haesebrouck, Freddy; Baele, Margo; Keyser, H.; Hermans, Katleen; Pasmans, Frank

2009-01-01

222

On uranyl malonate behaviour in concentrated acetic acid under hydrothermal conditions  

International Nuclear Information System (INIS)

Long-term heating of UO2(OOC)2CH2·3H2O malonate up to 165 deg C when placed under the glacial acetic acid layer results in production of [UO2(OOCCH3)2·HOOCCH3]2 acetate (I). Within I electroneutral dimer U atom (coordination number 7) is surrounded by a bidentate-chelate acetate-ion (U-O average bond length is 2.452(3) A), by HOOCCH3 molecule (bond length is 2.391(3) A) and by a bidentate-bridging acetate-ion (U-O average bond length is 2.326(3) A). The fundamental difference between I and the previously investigated dimer of the similar composition lies in HOOCCH3 molecule turn in such a way that two-dimensional line of strong hydrogenous bonds linking dimers in layers perpendicular to [100] direction is formed within the crystal

2008-01-01

223

Photochemistry and Vibrational Spectroscopy of the Trans and Cis Conformers of Acetic Acid in Solid Argon  

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Acetic acid monomer has two stable geometries, the cis and trans conformers. The high-energy cis conformer has been recently detected experimentally for the first time [Maçôas et al. J. Am. Chem. Soc. 2003, 125, 16188]. The cis conformer can be produced in low-temperature rare-gas matrixes upon vibrational excitation of the ground-state trans conformer. Fast tunneling from cis- to trans-acetic acid takes place even at the lowest working temperatures (8 K), limiting the time available to stu...

Mac?o?as, E. M. S.; Khriachtchev, L.; Fausto, R.; Ra?sa?nen, M.

2004-01-01

224

Acetic acid bacteria and the production and quality of wine vinegar.  

Science.gov (United States)

The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria. Despite the different methods of vinegar production (more or less designated as either "fast" or "traditional"), the use of pure starter cultures remains far from being a reality. Uncontrolled mixed cultures are normally used, but this review proposes the use of controlled mixed cultures. The acetic acid bacteria species determine the quality of vinegar, although the final quality is a combined result of technological process, wood contact, and aging. This discussion centers on wine vinegar and evaluates the effects of these different processes on its chemical and sensory properties. PMID:24574887

Mas, Albert; Torija, María Jesús; García-Parrilla, María del Carmen; Troncoso, Ana María

2014-01-01

225

Extractive Distillation of Acetic Acid from its Dilute Solution using Lithium Bromide  

Directory of Open Access Journals (Sweden)

Full Text Available Separation and purification are an integral part and a major cost factor in the chemical industry. Distillation is a very commonly used for solvent separation and purification process. It is neither cost effective nor process efficient when dealing with close-boiling and azeotropic solvent mixtures without modifying the relative volatility of the solvent components with an extraneous solvent or a non-volatile solute electrolyte or nonelectrolyte. The selection of a suitable modifier generally depends on the experimental determination of its effect on the Vapour–Liquid Equilibrium (VLE of the solvent mixture. Acetic acid is most widely used as aliphatic carbonic acid. It is frequently used as a solvent like in manufacture of cellulose acetate or in manufacture of many pharmaceutical products. Aqueous acetic acid is obtained during these processes and recovery of which is of great significance. Separation of pure water from dilute solution of Acetic acid –water mixture in the concentration range of 1 % to 30 % Acetic acid by simple rectification is almost impossible as relative volatility of the mixture in this range approaches unity.We would then require towers with large number of stages which would be operated with high reflux ratio and required high energy costs and operating costs. In practice extraction with suitable solvent is carried out before pure recovery occurs during the rectification of azeotropic mixture. An alternative separation process is the addition of Lithium Bromide(LiBr salt into acetic-acid water solution . Lithium bromide is largely soluble in water. Addition of salt will increase the boiling point of salt-water solution, there by separating comparatively pure acetic acid as overhead product. LiBr–water solution remains as residue from which LiBr can be readily separated by evaporation and reused. Experiments are carried out in laboratory with different concentrations of Acetic acid-water, in Othmer still which is vapor-liquid equilibrium apparatus. An Extractive distillation column will be designed based on experimental results. Cost analysis of this new separation technique will be carried out. The experimental data will be correlated to any model to calculate activity coefficients

R.P.Bhatt

2012-04-01

226

Growing and laying performance of Japanese quail fed diet supplemented with different concentrations of acetic acid  

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In order to evaluate the effect of acetic acid on growing and laying performance of Japanese Quail (JQ), 180 15-day-old JQ were divided into 4 groups. During the growing (15-42 days of age) and laying (43-84 days of age) periods, the groups fed the same basal diets supplemented with 0, 1.5, 3 and 6% of acetic acid. Each diet was fed to five replicates of 9 JQ (3 males:6 females) during the growing period. During the laying period, 128 birds were housed in 32 cages (4 birds per cage, 1 male...

Attia, Youssef A.; Abd El-hamid, Abdul E.; Ellakany, Hany F.; Fulvia Bovera; Al-harthi, Mohammed A.; Ghazaly, Sharehan A.

2013-01-01

227

Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid and methylglyoxal  

Directory of Open Access Journals (Sweden)

Full Text Available Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including pyruvate, oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA. Acetic acid plays a central role in the aqueous oxidation of methylglyoxal and it is a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid (20 ?M–10 mM was oxidized by OH radicals, and pyruvic acid and methylglyoxal experimental samples were analyzed using new analytical methods, in order to better understand the formation of SOA from acetic acid and methylglyoxal. Glyoxylic, glycolic, and oxalic acids formed from acetic acid and OH radicals. In contrast to the aqueous OH radical oxidation of methylglyoxal, the aqueous OH radical oxidation of acetic acid did not produce succinic acid and oligomers. This suggests that the methylgloxal-derived oligomers do not form through the acid catalyzed esterification pathway proposed previously. Using results from these experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

Y. Tan

2012-01-01

228

Polarographic study of Cd(2), Pb(2), Hg(1) in anhydrous acetic acid  

International Nuclear Information System (INIS)

Anhydrous acetic acid is a solvent which can be compared to water as far as its behaviour towards acid-base reactions is concerned. It is in fact, like water both a proton acceptor (basic) - and as such it can provoke the dissociation of acids - and a proton donor (acid). This amphoteric behaviour is characterized by the equilibrium: 2 H O Ac ? Ac OH2+ + Ac O- with Ki = |Ac O H2|+ |Ac O-| = 10-14.5 analogue to 2 H2O ? H3O+ + HO- with Ki = |H3O+| |HO-| = 10-14 The acid-base reactions can in principle be characterized by a pH scale based on a definition similar to that for the pH scale in aqueous solutions. The essential difference however between aqueous and acetic acid solutions is due to the fact that acetic acid has a low dielectric constant. ? = 6.1 (at 25 deg. C) The ions therefore remain associated, almost completely, in the form of ion-pairs produced as a result of the strong electrostatic interactions. This phenomenon requires us to modify the reasoning usually applied to aqueous solutions. The new general methods of reasoning have been established and discussed by G. CHARLOT and B. TREMILLON. We will make use of them for the particular case under consideration. In the first part, we have employed the polarographic method for the study of the acetic complexes of two elements: cadmium(II) and lead (II). In the second part we have tried to show that mercurous halides are formed in acetic acid; we have attempted to determine their stability. (author)

1966-01-01

229

Process control, energy recovery and cost savings in acetic acid wastewater treatment  

International Nuclear Information System (INIS)

An anaerobic fixed bed loop (AFBL) reactor was applied for treatment of acetic acid (HAc) wastewater. Two pH process control concepts were investigated; auxostatic and chemostatic control. In the auxostatic pH control, feed pump is interrupted when pH falls below a certain pH value in the bioreactor, which results in reactor operation at maximum load. Chemostatic control assures alkaline conditions by setting a certain pH value in the influent, preventing initial reactor acidification. The AFBL reactor treated HAc wastewater at low hydraulic residence time (HRT) (10-12 h), performed at high space time loads (40-45 kg COD/m3 d) and high space time yield (30-35 kg COD/m3 d) to achieve high COD (Chemical Oxygen Demand) removal (80%). Material and cost savings were accomplished by utilizing the microbial potential for wastewater neutralization during anaerobic treatment along with application of favourable pH-auxostatic control. NaOH requirement for neutralization was reduced by 75% and HRT was increased up to 20 h. Energy was recovered by applying costless CO2 contained in the biogas for neutralization of alkaline wastewater. Biogas was enriched in methane by 4 times. This actually brings in more energy profits, since biogas extra heating for CO2 content during biogas combustion is minimized and usage of other acidifying agents is omitted.

2011-02-28

230

Successive adsorption of methanol, butylamine, and acetic acid on titanium dioxide  

Energy Technology Data Exchange (ETDEWEB)

The sequence of modification of TiO/sub 2/ by amines and alcohols or by acids and alcohols affects the value of the adsorption of the individual substances and the nature of the mixed adsorption layers formed in this case. The adsorption layer formed in the modification of rutile first with methanol and then with n-butylamine is denser with respect to the adsorption of benzene and more resistant to the action of water vapors in comparison with the adsorption layer formed when these modifiers were applied in the reverse order. The modification of TiO/sub 2/ by acid and alcohol in any sequence leads to an interaction of them with one another in the adsorption layer; methanol displaces only part of the preadsorbed molecules of acetic acid from the surface, while the acid displaces virtually all of the alcohol. Under moist conditions the adsorption layer obtained by applying acetic acid on rutile with preadsorbed methanol is more stable.

Isirikyan, A.A.; Mikhailova, S.S.; Polunina, I.A.; Tolstaya, S.N.

1985-09-01

231

Monolaurin and acetic acid inactivation of Listeria monocytogenes attached to stainless steel.  

Science.gov (United States)

Individual and combined antimicrobial effects of monolaurin and acetic acid on Listeria monocytogenes planktonic cells or stainless-steel-adherent cells were determined in order to evaluate cell viability during a 25-min exposure period at 25 degrees C. A 10(7)-colony-forming units (CFU)/ml population of planktonic cells was completely inactivated by the synergistic combination of 1% acetic acid with 50 or 100 microg/ml of monolaurin within 25 or 20 min, respectively. Either compound alone caused partial but incomplete inactivation within the same time periods. A population of 10(5) CFU/cm2 of 1-day adherent cells on stainless steel was completely inactivated within 25 min, but with the highest concentrations of the combined chemicals, i.e., 1% acetic acid and 100 microg/ml of monolaurin. The combined chemical treatment again synergistically produced greater inhibition. A 10(6)-CFU/cm2 population of 7-day adherent cells was not completely inactivated within 25 min of exposure, although counts did decline. The results demonstrate increased resistance of attached L. monocytogenes to acetic acid and monolaurin and show that resistance increased with culture age. Combinations of organic acids and monolaurin might be considered as sanitizers of food contact surfaces, but activities of such combinations are likely to be less than other commonly used sanitizers. PMID:10463441

Oh, D H; Marshall, D L

1996-03-01

232

Acetate induced enhancement of photocatalytic hydrogen peroxide production from oxalic acid and dioxygen.  

Science.gov (United States)

The addition of acetate ion to an O2-saturated mixed solution of acetonitrile and water containing oxalic acid as a reductant and 2-phenyl-4-(1-naphthyl)quinolinium ion (QuPh(+)-NA) as a photocatalyst dramatically enhanced the turnover number of hydrogen peroxide (H2O2) production. In this photocatalytic H2O2 production, a base is required to facilitate deprotonation of oxalic acid forming oxalate dianion, which acts as an actual electron donor, whereas a Brønsted acid is also necessary to protonate O2(•-) for production of H2O2 by disproportionation. The addition of acetate ion to a reaction solution facilitates both the deprotonation of oxalic acid and the protonation of O2(•-) owing to a pH buffer effect. The quantum yield of the photocatalytic H2O2 production under photoirradiation (? = 334 nm) of an O2-saturated acetonitrile-water mixed solution containing acetate ion, oxalic acid and QuPh(+)-NA was determined to be as high as 0.34, which is more than double the quantum yield obtained by using oxalate salt as an electron donor without acetate ion (0.14). In addition, the turnover number of QuPh(+)-NA reached more than 340. The reaction mechanism and the effect of solvent composition on the photocatalytic H2O2 production were scrutinized by using nanosecond laser flash photolysis. PMID:23631436

Yamada, Yusuke; Nomura, Akifumi; Miyahigashi, Takamitsu; Ohkubo, Kei; Fukuzumi, Shunichi

2013-05-01

233

Formic and acetic acid: Valence threshold photoelectron and photoionisation total ion yield studies  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer High-resolution threshold photoelectron spectrum of formic acid. Black-Right-Pointing-Pointer High-resolution total photo-ion yield spectrum of formic acid. Black-Right-Pointing-Pointer High-resolution threshold photoelectron spectrum of acetic acid. Black-Right-Pointing-Pointer High-resolution total photo-ion yield spectrum of acetic acid. -- Abstract: The carboxylic acids (formic and acetic) have been studied using threshold photoelectron (TPE) and total photoion yield (TPIY) spectroscopies; simultaneously obtained spectra of formic acid (HCOOH) were recorded over the entire valence ionisation region from 11-21 eV at a resolution of {approx}12 meV. Higher resolution spectra ({approx}6 meV) were also obtained in the energy region of the lowest two cationic states. Analysis of the TPE spectrum in this energy range agreed very favorably with the best available conventional photoelectron (PE) spectrum of formic acid. Autoionising Rydberg structure was observed in the TPIY spectrum of formic acid and is attributed primarily to the presence of the npa Prime Leftwards-Arrow 8a Prime Rydberg series converging on to the 3{sup 2}A Prime ionic state of formic acid. Preliminary results, at a resolution of {approx}8 meV, were obtained for acetic acid (CH{sub 3}COOH) over the onset of the ionisation energy region. The TPE spectrum was found to be very similar to the best published photoelectron spectrum, but no Rydberg structure was observed in the TPIY spectrum.

Siggel-King, Michele R.F., E-mail: michele.siggel-king@stfc.ac.uk [Cockcroft Institute, Daresbury Science and Innovation Campus, Daresbury, Warrington WA4 4AD (United Kingdom); Department of Physics, University of Liverpool, Liverpool L69 3BX,UK (United Kingdom); Yencha, Andrew J. [Department of Chemistry, State University of New York at Albany, Albany, NY 12222 (United States); King, George C. [Department of Physics and Astronomy and Photon Science Institute, Manchester University, Manchester M13 9PL (United Kingdom); Malins, Andrew E.R. [Cockcroft Institute, Daresbury Science and Innovation Campus, Daresbury, Warrington WA4 4AD (United Kingdom); Eypper, Marie [School of Chemistry, University of Southampton, Southampton SO17 1BJ (United Kingdom)

2012-09-15

234

Investigation on Ethylenediaminetetra-Acetic Acid as Corrosion Inhibitor for Mild Steel in 1.0M Hydrochloric Acid  

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The influence of ethylenediaminetetra-acetic acid (EDTA) on the corrosion of mild steel in 1.0 M hydrochloric acid solution was investigated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The efficiency of EDTA was compared with thiourea. Primary results obtained revealed that EDTA performed as good corrosion inhibitor for mild steel in 1.0 M hydrochloric acid media comparing with thiourea. Polarization curves show that the behavior of EDTA and thio...

Musa, Ahmed Y.; Kadhum, Abdul Amir H.; Mohd Sobri Takriff; Abdul Razak Daud; Siti Kartom Kamarudin

2009-01-01

235

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS)  

Science.gov (United States)

Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS) can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv-1) at a drift tube field strength of 132 townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC). An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?), an intercept of 0.049 ± 20 (2?) ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

Haase, K. B.; Keene, W. C.; Pszenny, A. A. P.; Mayne, H. R.; Talbot, R. W.; Sive, B. C.

2012-07-01

236

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS  

Directory of Open Access Journals (Sweden)

Full Text Available Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv?1 at a drift tube field strength of 132 townsend (Td. Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC. An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?, an intercept of 0.049 ± 20 (2? ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

K. B. Haase

2012-07-01

237

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS)  

Science.gov (United States)

Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS) can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv?1) at a drift tube field strength of 132 townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC). An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?), an intercept of 0.049 ± 20 (2?) ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

Haase, K. B.; Keene, W. C.; Pszenny, A. A. P.; Mayne, H. R.; Talbot, R. W.; Sive, B. C.

2012-01-01

238

Protective Effect of Alpha-lipoic Acid Against Lead Acetate-Induced Oxidative Stress in the Bone Marrow of Rats  

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The present study was designed to investigate the effects of alpha Lipoic Acid (LA) against lead acetate induced changes in free radical scavenging enzymes and lipid hydroperoxides in bone marrow of rats. Rats were exposed to lead acetate in their drinking water (500 ppm) for 14 days and alpha lipoic acid was given concurrently (25, 50 and 100 mg kg-1). Blood lead levels, lipid hydroperoxides, protein carbonyl contents and oxidative marker enzymes were estimated. Lead acetate in dr...

2011-01-01

239

Population dynamics of acetic acid bacteria during traditional wine vinegar production.  

Science.gov (United States)

The population dynamics of acetic acid bacteria in traditional vinegar production was determined in two independent vinegar plants at both the species and strain level. The effect of barrels made of four different woods upon the population dynamics was also determined. Acetic acid bacteria were isolated on solid media and the species were identified by RFLP-PCR of 16S rRNA genes and confirmed by 16S rRNA gene sequencing, while strains were typed by ERIC-PCR and (GTG)(5)-rep-PCR. The most widely isolated species was Acetobacter pasteurianus, which accounted for 100% of all the isolates during most of the acetification. Gluconacetobacter europaeus only appeared at any notable level at the end of the process in oak barrels from one vinegar plant. The various A. pasteurianus strains showed a clear succession as the concentration of acetic acid increased. In both vinegar plants the relative dominance of different strains was modified as the concentrations of acetic acid increased, and strain diversity tended to reduce at the end of the process. PMID:20117853

Vegas, Carlos; Mateo, Estibaliz; González, Angel; Jara, Carla; Guillamón, José Manuel; Poblet, Montse; Torija, Ma Jesús; Mas, Albert

2010-03-31

240

Phase behaviour of aqueous mixtures of acetic acid with isomers of xylene  

International Nuclear Information System (INIS)

Highlights: • The binodal curve and tie line data were obtained for four systems. • These systems are (water + acetic acid + o-xylene, m-xylene, p-xylene or xylenes). • Distribution coefficients and separation factors were measured. • Extraction of acetic acid by mixed xylenes is more suitable. • Experimental LLE data were correlated using NRTL model. -- Abstract: (Liquid–liquid) equilibrium (LLE) data of the solubility curves and tie-line compositions have been determined for mixtures of (water + acetic acid + organic solvent (o-xylene, m-xylene or p-xylene)) at T = 298.15 K and atmospheric pressure. The mixed isomers (xylenes) are also used as a mixed-solvent like the individual isomers and phase behaviour of (water + acetic acid + xylenes) is investigated. The experimental LLE data were correlated using the NRTL model, and the binary interaction parameters were obtained. Distribution coefficients and separation factors have been evaluated for the immiscibility region. The reliability of the experimental tie-lines has been confirmed by using Othmer–Tobias correlation

2013-12-01

 
 
 
 
241

GENE EXPRESSION PATTERNS OF CD-1 DAY-8 EMBRYO CULTURES EXPOSED TO BROMOCHLORO ACETIC ACID  

Science.gov (United States)

Gene expression patterns of CD-1 day-8 embryo cultures exposed to bromochloro acetic acid Edward D. Karoly?*, Judith E. Schmid* and E. Sidney Hunter III* ?Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and *Reproductiv...

242

The structure and pervaporation properties for acetic acid/water of polydimethylsiloxane composite membranes  

International Nuclear Information System (INIS)

Highlights: ? The membranes were prepared using AMEO as a substitute of cross-linker TEOS. ? OMMT was used as filler to improve the pervaporation performance of membrane. ? PDMS-AMEO/OMMT/PES composite membrane was used in acetic acid/water separation. -- Abstract: Polydimethylsiloxane (PDMS)/organic montmorillonite (OMMT)/polyether polyethersulfone (PES) composite membranes were prepared by in situ anionic polymerization using 3-aminopropyltrimethoxy (AMEO) as a crosslinker. The morphology, thermal properties and interaction of PDMSAMEO/OMMT membranes were characterized by using a scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and a thermal gravimetric analysis (TGA). The swelling behavior of membranes without PES support was investigated. The effects of AMEO content and OMMT content on separation properties were also studied. The results show that the addition of appropriate OMMT could improve the hydrophobic and pro-acetic acid properties of a membrane. The acetic acid selectivity of membranes was best when AMEO content was 0.1. The membrane, loading 2 wt.% OMMT, exhibited the highest separation factor for a feed concentration of 10 wt.% at 313 K. An increase in feed concentration resulted in the enhancement of flux and selectivity. When the feed concentration was above 20 wt.%, the separation factor of a filled membrane was larger than for an unfilled membrane. With increases in the feed temperature, the permeation flux of membranes increased. However, the acetic acid selectivity of an unfilled membrane decreased but for filled membranes initially increased before decreasing.

2012-02-01

243

Evaluating the effect of a mixture of alcohol and acetic acid for otomycosis therapy  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction and objective: Otomycosis is a fungal infection of external auditory meatus. The acute form of the disease causes secretion and pruritus. The usual prescribed medicines for otomycosis are topical clotrimazole 1%, amphotericin B and otosporin. The aim of the present study was to evaluate the efficacy of treatment with isopropyl alcohol and acetic acid for otomycosis.Materials and methods: In the present study 910 patients examined and those suspected to have otomycosis referred to medical mycology laboratory of Golabchi, Kashan. A questionnaire was also filled for each patient. Both direct and culture examinations were used to confirm otomycosis in the patients. Then the patients were treated with the mixture of isopropyl alcohol+acetic acid. Results: Out of 910 examined patients, 60 patients were suspected to have otomycosis and referred to medical mycology lab. Mycological examinations confirmed otomycosis in 52 patients (86.7%. Most of the patients (78.8% were cured perfectly after therapy with the mixture of alcohol and acetic acid. After three weeks, in addition to elimination of clinical signs further smear showed no sign of disease. However in four patients there was a relapse of the disease.Conclusion: Due to therapeutic effect of the mixture of isopropyl alcohol and acetic acid for otomycosis, its low side effects and low rate of relapse, it is recommended to use this mixture for the treatment of otomycosis.

Ahmad Yaganeh Moghadam

2010-04-01

244

Stability of cadmium complex with octaphenyltetrazaporphin and its solvoprotolytic dissociation in pyridine-acetic acid medium  

International Nuclear Information System (INIS)

Solvoprotolytic dissociation of octaphenyltetrazaporphin cadmium complex in acetic acid solutions in pyridine is investigated. It is stated that its dissociation is obeyed submitted the first order by the complex and the second order by solvated proton. Comparison with cadmium complexes of other porphyrins is carried out

1982-01-01

245

The Biological Evaluation of Poly (Vinyl Acetate-Co-Crotonic Acid) Ionomer Hydrogel Coatings.  

Science.gov (United States)

Poly(vinyl acetate-co-2%-crotonic acid) 60% sodium ionomer hydrogel was found to be the most thromboresistant hydrogel evaluated in our screening studies. The ionomer hydrogel was graft-coated onto substrate surfaces from an ethanol solution of its monome...

W. F. Beach D. D. Stewart

1980-01-01

246

Radiolysis of aqueous solutions of acetic acid in the presence of Na-montmorillonite  

Science.gov (United States)

The gamma-irradiation of 0.8 mol dm-3 aqueous, oxygen-free acetic acid solutions was investigated in the presence or absence of Na-montmorillonite. H2, CH4, CO, CO2, and several polycarboxylic acids were formed in all systems. The primary characteristics observed in the latter system were: (1) Higher yield of the decomposition of acetic acid; (2) Lower yield of the formation of polycarboxylic acids; (3) No effect on the formation of methane; (4) Higher yield of the formation of carbon dioxide; and (5) The reduction of Fe3+ in the octahedral sites of Na-montmorillonite. A possible reaction scheme was proposed to account for the observed changes. The results are important in understanding heterogeneous processes in radiation catalysis and might be significant to prebiotic chemistry.

Navarro-Gonzalez, R.; Negron-Mendoza, A.; Ramos, S.; Ponnamperuma, C.

1990-01-01

247

TGA-FTIR study of the vapors released by triethylamine-acetic acid mixtures  

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Proprietary mixtures of amines and carboxylic acids are used as volatile corrosion inhibitors (VCIs) for the protection of iron and steel components against atmospheric corrosion. This study was focused on the nature of the vapors they release. VCI model compounds comprising mixtures of triethylamine and acetic acid were studied using thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy (TGA–FTIR) at 50 ?C. As vaporization progressed, the composition...

Nhlapo, Nontete Susan; Focke, Walter Wilhelm; Vuorinen, Eino

2012-01-01

248

Supported Ionic Liquid Phase (SILP) Catalysis for the Production of Acetic acid by Methanol Carbonylation  

DEFF Research Database (Denmark)

The work presented here is focused on the development of a new reaction process. It applies Supported Ionic Liquid Phase (SILP) catalysis to a specific reaction. By reacting methanol and carbon monoxide over a rhodium catalyst, acetic acid can be formed. This reaction is important on a large scale industrially, with millions of tonnes of acetic acid being produced annually. Acetic acid is an important precursor for making adhesives, plastics and fabrics. By using the SILP concept we are able to carry out the reaction in a continuous system, allowing a steady production of acetic acid without having to stop and re-start the reaction. This sort of continuous flow reaction is a subject of great research effort in recent years as it is more sustainable (and in some cases financially viable) that the current method of carrying out chemical reactions in large size batch reactions The project started right at the beginning with the construction of a suitable test reactor, then followed by the synthesis and testing of all the catalysts reported. A variety of nitrogen based ionic liquids were initially tested, giving good results and stability in the system. Later a number of phosphonium based salts were tested (these were no longer classified as ionic liquids due to melting points above 100â?¦C). The phosphonium salts showed even better activity in the system compared to the ionic liquids. Overall the work has shown that this process for the manufacture of acetic acid is viable industrially. This is backed up by the construction and operation of a pilot plant by Wacker Chemie AG in Munich.

Hanning, Christopher William

2012-01-01

249

Clostridium strain which produces acetic acid from waste gases  

Science.gov (United States)

A method and apparatus are disclosed for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration. 4 figs.

Gaddy, J.L.

1997-01-14

250

Clostridium stain which produces acetic acid from waste gases  

Energy Technology Data Exchange (ETDEWEB)

A method and apparatus for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration.

Gaddy, James L. (2207 Tall Oaks Dr., Fayetteville, AR 72703)

1997-01-01

251

An Improved Ion Chromatography Methods for Analysis of Acetic and Formic Acid Vapours  

Directory of Open Access Journals (Sweden)

Full Text Available Air quality monitoring for acetic and formic acid vapours inmuseum galleries and storage environments is commonlyconducted using passive sampling and ion chromatography(IC. We report development of a rapid IC method with 2 to60-fold improvement in detection limits for acetate and formate. Baseline resolution is achieved in 4.5 min using anAS11-HC anion exchange column with 4 mM NaOH eluent at1.5 mL/min flow rate. The detection limits are 12 µg/mL(0.24 ng for acetate and 11 µg/mL (0.21 ng for formate.The method was successfully used for air quality monitoring in a Los Angeles museum warehouse.

Robyn E. Hodgkins

2011-01-01

252

Oxygen-dependent catabolism of indole-3-acetic acid in Bradyrhizobium japonicum.  

DEFF Research Database (Denmark)

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid (IAA). Examination of this catabolism in strain 110 by in vivo experiments has revealed an enzymatic activity catalyzing the degradation of IAA and 5-hydroxy-indole-3-acetic acid. The activity requires addition of the substrates for induction and is oxygen dependent. The highest activity is obtained when the concentration of inducer is 0.2 mM. Spectrophotometric data are consistent with the suggestion that the indole ring is broken during degradation of IAA. We hypothesize that the enzyme catalyzes an oxygen-consuming opening of the indole ring analogous to the one catalyzed by tryptophan 2,3-dioxygenase. The pattern of metabolite usage by known tryptophan-auxotrophic mutants and studies of metabolites by high-performance liquid chromatography indicate that anthranilic acid is a terminal degradation product in the proposed pathway. Udgivelsesdato: 1991-Aug

Egebo, L A; Nielsen, S V

1991-01-01

253

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct difference between nitrifying activated sludge and suspended biofilm carrier removal of several pharmaceuticals was demonstrated. Biofilm carriers from full-scale nitrifying wastewater ...

Fala?s, Per; Baillon-dhumez, Aude; Andersen, Henrik Rasmus; Ledin, A.; La Cour Jansen, Jes

2011-01-01

254

Study on dissociation and solvation in water-acetic acid mixtures  

International Nuclear Information System (INIS)

The addition of acetic acid to water produces media of varying dielectric constant. The concepts of dissociation and solvation were defined in water-acetic acid mixtures containing from 5 per cent to 100 per cent water. The extent to which the activity of water and that of acetic acid participate in the solvation of molecules and of ions was demonstrated. The variation in the dissociation constants of HClO4, HCl and BH+ type acids and that of the ionic products can be interpreted by considering only the activity of the components of the mixture. These constants verify simple empirical relationships of the type pK = = Cte - p log (aH2O) - q log (aHOAc). By estimating the activity coefficients of ion and molecule solvation it was possible to determine their respective influences on the dissociation constants, of BH+ cationic acids. Thus the effect of medium on the constants appears as the sum of separate effects of medium of the chemical species B, H and BH+ taking part, in the reactions. Solvation of the B molecules and of the BH+ ions therefore depends to a large extent on the nature of the base. A study of the redox function R0 defined by Strehlow enabled the activity coefficients of solvation of the ions H+, Ag+, Cl-, Br- and I- to be determined. In the case of protons, the methods of Latimer and Izmailov lead to experimental results very similar to those obtained by the Strehlow's method. (author)

1970-01-01

255

Formic and acetic acid over the central Amazon region, Brazil. I - Dry season  

Science.gov (United States)

The concentrations of formic and acetic acids in the gas phase, atmospheric aerosol, and rainwater samples collected in Amazonia at ground level and in the atmosphere during the Amazon Boundary Layer Experiment in July/August 1985 were analyzed by ion exchange chromatography. The diurnal behavior of both acids at ground level and their vertical distribution in the forest canopy point to the existence of vegetative sources as well as to production by chemical reactions in the atmosphere. The concentrations of formic and acetic acids in the gas phase were about 2 orders of magnitude higher than the corresponding concentrations in the atmospheric aerosol. In rainwater, the total formate and acetate represented about one half of the anion equivalents, in contrast to less than 10 percent of the soluble anionic equivalents contributed by these acids in the atmospheric aerosol. The observed levels of these ions in rainwater are considered to be the result of a combination of chemical reactions in hydrometeors and the scavenging of the gaseous acids by cloud droplets.

Andreae, M. O.; Andreae, T. W.; Talbot, R. W.; Harriss, R. C.

1988-01-01

256

Observation of SERS of picolinic acid and nicotinic acid using cellulose acetate films doped with Ag fine particles  

Science.gov (United States)

Surface enhanced Raman (SER) spectra of picolinic acid and nicotinic acid were observed using cellulose acetate (CA) films doped with Ag fine particles. The spectra obtained match those reported for silver colloids though some differences in SER band intensity were observed. The ease of preparation and handling of the CA film method renders it more useful than the colloid method for the observation of SER spectra.

Imai, Yoshika; Kurokawa, Yoichi; Hara, Masaru; Fukushima, Michiko

1997-10-01

257

Possibility of formic and acetic acids as active substrates for methanogenesis in the groundwater in Horonobe, Hokkaido  

International Nuclear Information System (INIS)

Groundwater samples in Horonobe district, Hokkaido, were analyzed to evaluate the possibility that formic and acetic acids are active substrates for methanogens in Quaternary and Neogene (Koetoi formation) formations. ?Gr corresponding to CH4-producing reactions indicates that both acids could be active substrates in almost all sampling locations. However, acetic acid was recognized to be an active substrate only in the Koetoi formation on the basis of the principle of competitive exclusion (CE) of microorganisms. The limited possibility by the CE principle suggests that dynamic equilibrium between substrate production rates and consumption rates is established only in the Koetoi formation for acetic acid. (author)

2012-09-01

258

Solubilities of {?-D-glucose in water + (acetic acid or propionic acid)} mixtures at atmospheric pressure and different temperatures  

International Nuclear Information System (INIS)

Highlights: • The solubility of ?-D-glucose in binary mixtures has been obtained in this work. • The solubility decreases with the increase of volume fraction of water in the solvents. • The solubility of ?-D-glucose increases with the increase of temperature. • The results show that the three models agree well with the experimental data. • The Apelblat equation was more accurate than the ?h model and ideal model. -- Abstract: Using dynamic method and the laser monitoring observation technique, the solubility of ?-D-glucose in {water + (acetic acid or propionic acid)} was measured over the temperature range (297.55 to 331.45) K at atmospheric pressure. Its corresponding (solid + liquid) equilibrium data will provide essential support for industrial design and further theoretical studies. The solubility of ?-D-glucose in the mixtures of (water + acetic acid), and (water + propionic acid) was found to increase with increasing temperature and decrease with increasing volume fractions of acetic acid, and propionic acid in aqueous solution. The experimental data were correlated by using the Apelblat equation, the ?h equation and the ideal solution equation. The results showed that these three models agreed well with the experimental values, and the Apelblat equation was found to regress the solubility data better than the other two models

2013-10-01

259

Effect of lactic, acetic and citric acids on quality changes of refrigerated green mussel, Perna viridis (Linnaeus, 1758  

Directory of Open Access Journals (Sweden)

Full Text Available Effect of lactic, acetic and citric acids on the quality changes and shelf-life extension of green mussel stored at 4oC was investigated. The inhibitory effect on bacterial growth was pronounced when the concentration of lactic, acetic and citric acids increased (P<0.05. Green mussel dipped with lactic acid had the lower total volatile base, trimethylamine, ammonia and TCA-soluble peptides contents than those dipped in acetic and citric acids. However, the increases in exudates loss and cooking loss were observed in samples dipped in organic acids, causing the denaturation of muscle protein by acids used. Thiobarbituric acid reactive substances (TBARS increased as the organic acid concentration increased (P<0.05. Lactic acid dipped samples, particularly with 0.2 M, showed the greater acceptability than did those dipped in other acids throughout the storage of 27 days. The control sample had the acceptability only for 6 days of storage.

Payap Masniyom

2007-07-01

260

Electron spin resonance studies of barriers to hindered rotation in acetic acid, acetamide, and peptide radicals  

International Nuclear Information System (INIS)

Activation energies for methyl group rotation in the radicals of type H3C-C2O) as well as in 8 M NaOD glasses have produced the acetic acid anion, the acetate dianion, and the acetamide anion. ESR spectra of these have revealed a doublet (ca. 32G) at 90 K reversibly interconverting to a 1:3:3:1 quartet, of ca. 15-G hyperfine splitting, at higher temperatures (170 K). This interconversion has been attributed to the hindered internal rotation of the methyl group about the H3C-C< bond. The ESR spectra are analyzed using modified Bloch equations for the three-jump process. The mean lifetime (tau) at each temperature (T) has been estimated by a comparison of experimental and simulated ESR spectra. The activation energy (E/sub a/) for the sixfold barrier to the rotation is found to be 5.0 +- 0.5 kcal/mol in the acetate dianion and is about 3.0 kcal/mol for the acetate and acetamide as well as N-acetylamino acids. ESR spectra characteristic of the tunneling methyl group were observed at low temperature (20 K< T<100K) for the radicals produced in ?-irradiated polycrystalline samples of glycyl-L-alanine and L-alanyl-L-alanine. 3 figures, 1 table

1979-05-17

 
 
 
 
261

Calibration and intercomparison of acetic acid measurements using proton-transfer-reaction mass spectrometry (PTR-MS)  

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Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitations of available measurement techniques. This paper demonstrates that, when properly calibrated, proton-transfer-reaction mass spectrometry (PTR-MS) can be a valuable technique for...

2012-01-01

262

Investigation of Sesamol on Myeloperoxidase and Colon Morphology in Acetic Acid-Induced Inflammatory Bowel Disorder in Albino Rats  

Science.gov (United States)

Background. Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of gastrointestinal tract of immune, genetic, and environmental origin. In the present study, we examined the effects of sesamol (SES), which is the active constituent of sesame oil in the acetic acid (AA) induced model for IBD in rats. Methods. The groups were divided into normal control, AA control, SES, and sulfasalazine (SS). On day 7, the rats were killed, colon was removed, and the macroscopic, biochemical, and histopathological evaluations were performed. Results. The levels of MPO, TBARS, and tissue nitrite increased significantly (P < 0.05) in the AA group whereas they reduced significantly in the SES and SS treated groups. Serum nitrite levels were found to be insignificant between the different groups. Conclusions. The mucosal protective effects of sesamol in IBD are due to its potential to reduce the myeloperoxidase and nitrite content.

Kondamudi, Phani Krishna; Kovelamudi, Hemalatha; Mathew, Geetha; Nayak, Pawan G.; Rao, Mallikarjuna C.; Shenoy, Rekha R.

2014-01-01

263

PRODUCTION OF CAROTENOIDS (ANTIOXIDANTS/ COLOURANT IN SPIRULINA PLATENSIS IN RESPONSE TO INDOLE ACETIC ACID (IAA  

Directory of Open Access Journals (Sweden)

Full Text Available The Carotenoid compounds (antioxidants synthesis in spirulina platennsis was studied in vitro under the influence of the Indole Acetic Acid (IAA. Spirulina platensis is grown in Zarrouks medium supplemented with different concentration of Indole Acetic Acid ( 1?g/ml–10?g/ml . The gradual increase in the total Carotenoidscontent was recorded from 1- 6 ?g/ml of IAA. Inhibition in the synthesis of Carotenoids compounds was noticed in 7?g/ml-10?g/ml the similar trend was also observed with synthesis of chlorophyll a .Growth of Spirulina was also inhibited at higher level of IAA .Maximum production of Carotenoid compounds noticed at 6?g/ml IAA.

Munawer Khan Mohammed,

2011-06-01

264

DFT computation and experimental analysis of vibrational and electronic spectra of phenoxy acetic acid herbicides  

Science.gov (United States)

An absolute vibrational analysis has been attempted on the basis of experimental FTIR and NIR-FT Raman spectra with calculated vibrational wavenumbers and intensities of phenoxy acetic acids. The equilibrium geometry, bonding features and harmonic vibrational wavenumbers have been calculated with the help of B3LYP method with Dunning correlation consistent basis set aug-cc-pVTZ. The electronic structures of molecular fragments were described in terms of natural bond orbital analysis, which shows intermolecular Osbnd H⋯O and intramolecular Csbnd H⋯O hydrogen bonds. The electronic absorption spectra with different solvents have been investigated in combination with time-dependent density functional theory calculation. The pKa values of phenoxy acetic acids were compared.

Arul Dhas, D.; Hubert Joe, I.; Roy, S. D. D.; Balachandran, S.

2013-05-01

265

Conclusion on the peer review of the pesticide risk assessment of the active substance acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available The conclusions of the European Food Safety Authority (EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State, Germany, for the pesticide active substance acetic acid are reported. The context of the peer review was that required by Commission Regulation (EC No 2229/2004, as amended by Commission Regulation (EC No 1095/2007 and Commission Regulation (EU No. 114/2010. The conclusions were reached on the basis of the evaluation of the representative uses of acetic acid as a herbicide in pome fruit, stone fruit, paths and roads, ornamental trees and shrubs, turf, and lawns. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and literature in the dossier peer reviewed, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

European Food Safety Authority

2013-01-01

266

Acetic Acid Formation by Selective Aerobic Oxidation of Aqueous Ethanol over Heterogeneous Ruthenium Catalysts  

DEFF Research Database (Denmark)

Heterogeneous catalyst systems comprising ruthenium hydroxide supported on different carrier materials, titania, alumina, ceria, and spinel (MgAl2O4), were applied in selective aerobic oxidation ethanol to form acetic acid, an important bulk chemical and food ingredient. The catalysts were characterized by X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and nitrogen physisorption and utilized in the oxidation of 2.5â??50 wt % aqueous ethanol solutions at elevated temperatures and pressures. The effects of Ru metal loading, pretreatment of catalysts, oxidant pressure, reaction temperature, and substrate concentration were investigated. Quantitative yield of acetic acid was obtained with 1.2 wt % Ru(OH)x/CeO2 under optimized conditions (150 °C, 10 bar O2, 12 h of reaction time, 0.23 mol % Ru to substrate).

Gorbanev, Yury; Kegnæs, Søren

2012-01-01

267

The influence of Ni loading on coke formation in steam reforming of acetic acid  

Energy Technology Data Exchange (ETDEWEB)

Steam reforming of acetic acid on Ni/{gamma}-Al{sub 2}O{sub 3} with different nickel loading for hydrogen production was investigated in a tubular reactor at 600 C, 1 atm, H2O/HAc = 4, and WHSV = 5.01 g-acetic acid/g-cata.h{sup -1}. The catalysts were characterized by temperature programmed oxidation (TPO) and differential thermal analysis (DTA), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results showed that the amount of deposited carbidic-like carbon decreased and graphitic-like carbon increased with Ni loading increasing from 9 to 15 wt%. The Ni/{gamma}-Al{sub 2}O{sub 3} catalyst with 12 wt% Ni loading had higher catalytic activity and lower coke deposited rate. (author)

An, Lu; Dong, Changqing; Yang, Yongping; Zhang, Junjiao; He, Lei [National Engineering Laboratory of Biomass Power Generation Equipment, North China Electric Power University, Beijing 102206 (China)

2011-03-15

268

Chemical Cleaning Solvents; Boiler Descaling with Tetra-Ammonium Ethylene-Diamine Tetra-Acetic Acid.  

Science.gov (United States)

The tetraammonium salt of ethylenediamine tetraacetic acid is an effective agent for removing scale from naval boilers. The cleaning procedure effects significant savings in cleaning time and post-cleaning boiler readiness operations. However, the release...

T. J. Daly

1973-01-01

269

Anticoccidial effects of acetic acid on performance and pathogenic parameters in broiler chickens challenged with Eimeria tenella  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The objective of the present study was to evaluate the anticoccidial effect of the different concentrations of the acetic acid in the broiler chickens in comparison with the amprolium anticoccidial. A total of 198 chicks were placed 11 per pen with three pens per treatment. The different concentrati [...] ons (1%, 2% and 3%) of acetic acid and amproilum (at the dose rate of 125ppm) were given to the experimental groups in drinking water from 10-19th days of age. One group was kept as infected non medicated control and one as non infected non medicated control. All the groups were inoculated orally with 75,000 sporulated oocysts at the 12th day of age except non infected non medicated control. Anticoccidial effect was evaluated on the basis of performance (weight gain, feed conversion ratio) and pathogenic (oocyst score, lesion score and mortality %age) parameters. Among acetic acid medicated groups, the maximum anticoccidial effect was seen in the group medicated with 3% acetic acid followed by 2% and 1% acetic acid medicated groups. Amprolium and 3% acetic acid were almost equivalent in suppressing the negative performance and pathogenic effects associated with coccidiosis (Eimeria tenella) challenge. In summary, acetic acid has the potential to be used as alternative to chemotherapeutic drugs for Eimeria tenella control. Concentration-dependent anticoccidial effect of acetic acid suggests that further studies should be carried out to determine the possible maximum safe levels of acetic acid with least toxic effects to be used as anticoccidial.

Rao Z., Abbas; Shokat H., Munawar; Zahid, Manzoor; Zafar, Iqbal; Muhammad N., Khan; Muhammad K., Saleemi; Muhammad A., Zia; Arfan, Yousaf.

270

Kinetics of the vapor-phase synthesis of allyl acetate (AA) from propylene and acetic acid over palladium-based catalysts  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of the vapor-phase synthesis of allyl acetate (AA) from propylene and acetic acid over palladium-based catalysts containing 5% by wt of a complex palladium acetate Pd(NH/sub 3/)/sub 4/(CH/sub 3/COO)/sub 2/ and 2.5, 5, and 5% of copper, zinc, and sodium acetates, respectively, supported on active alumina thermally treated at 900/sup 0/C were studied in a flow reactor at 180/sup 0/-210/sup 0/C and partial pressures of propylene, oxygen, and acetic acid 1.875-4.83, 0.06-0.35, and 0.1-0.72 atm, respectively. Separate experiments showed that carbon dioxide, formed at 2-2.5% under the conditions studied, was a product of the catalytic oxidation of propylene. The rate of AA synthesis was first order in oxygen, and that of CO/sub 2/ formation was second order in oxygen and minus first order in propylene. Kinetic equations for these reactions were derived by assuming a mechanism similar to one previously proposed for propylene oxychlorination to allyl chloride over palladium-copper chloride catalysts, and a reaction scheme was proposed involving the formation of polyfunctional active sites of a PdCu/sub m/(CH/sub 3/COO)/sub n/ type, which react with proplyene to give AA and (after conversion to an oxidized form) with propylene to form CO/sub 2/.

Mardzhanyan, G.G.; Khachatryan, S.S.; Avetisov, A.K.; Gelbshtein, A.I.; Boyadzhyan, V.K.; Stepanyan, G.G.

1980-06-01

271

Control of Acetic Acid Fermentation by Quorum Sensing via N-Acylhomoserine Lactones in Gluconacetobacter intermedius? †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A number of gram-negative bacteria regulate gene expression in a cell density-dependent manner by quorum sensing via N-acylhomoserine lactones (AHLs). Gluconacetobacter intermedius NCI1051, a gram-negative acetic acid bacterium, produces three different AHLs, N-decanoyl-l-homoserine lactone, N-dodecanoyl-l-homoserine lactone, and an N-dodecanoyl-l-homoserine lactone with a single unsaturated bond in its acyl chain, as determined by liquid chromatography-tandem mass spectrometry. Two genes enc...

Iida, Aya; Ohnishi, Yasuo; Horinouchi, Sueharu

2008-01-01

272

Correlation between urinary 2-methoxy acetic acid and exposure of 2- methoxy ethanol  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVES: To examine the correlation between airborne 2-methoxy ethanol (ME) exposures and the urinary 2-methoxy acetic acid (MAA) and to recommend a biological exposure index (BEI) for ME. METHODS: 8 Hour time weighted average (TWA) personal breathing zone samples and urine samples before and after the shift were collected from Monday to Saturday for 27 workers exposed to ME and on Friday for 30 control workers. RESULTS: No correlation was found between airborne exposure to ME and ur...

Shih, T. S.; Liou, S. H.; Chen, C. Y.; Chou, J. S.

1999-01-01

273

Application of molecular techniques for identification and ennumeration of acetic acid bacteria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Application of molecular techniques for identification and enumeration of acetic acid bacteria:Los principales objetivos de la tesis son el desarrollo de técnicas de biología molecular rápidas y fiables para caracterizar bacterias acéticas.Las bacterias acéticas son las principales responsables del picado de los vinos y de la producción de vinagre. Sin embargo, existe un desconocimiento importante sobre su comportamiento y evolución. Las técnicas de enumeración y de identificación b...

Gonza?lez Benito, Angel

2005-01-01

274

Bio-conversion of apple pomace into ethanol and acetic acid: Enzymatic hydrolysis and fermentation.  

Science.gov (United States)

Enzymatic hydrolysis of cellulose present in apple pomace was investigated using process variables such as enzyme activity of commercial cellulase, pectinase and ?-glucosidase, temperature, pH, time, pre-treatments and end product separation. The interaction of enzyme activity, temperature, pH and time had a significant effect (Papple pomace to yield sugars and concomitant bioconversion to produce ethanol and acetic acid. PMID:23334018

Parmar, Indu; Rupasinghe, H P Vasantha

2013-02-01

275

Staining of Proteins in Gels with Coomassie G-250 without Organic Solvent and Acetic Acid  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents (Methanol, Ethanol or 2-Propanol) and acetic acid are used for fixation, staining and destaining of proteins in a gel after SDS-PAGE. To speed up the procedure, heating the staining solution in the microwave oven for a short time is frequently used. This usually results in evaporation of toxic or hazardous Methanol, Ethanol or 2-Propanol and a stro...

Lawrence, Ann-marie; Besir, Hu?seyin

2009-01-01

276

Rapid and efficient synthesis of [1,2-_1_4C] acetic acid  

International Nuclear Information System (INIS)

The method for the synthesis of mmol quantities of [1,2-_1_4C] acetic acid with molar activity equal to or higher than 3.7 GBqxmmol"-_1 (100 mCixmmol"-_1) based on the step hydration and oxidation of [1,2"-_1_4C] ethine is described. The 85% radiochemical yield on starting Ba_1_4CO"3 was achieved. (author)

1983-06-28

277

The Enhancement of Catharanthine Content in Catharanthus roseus Callus Culture Treated with Naphtalene Acetic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available The research aim was to examine the enhancement of catharanthine content in Catharanthus roseus callus culture added with different concentration of Naphtalene Acetic Acid (NAA. NAA treatment produced callus that formed hairy roots. Fresh and dry weight of callus increased as the increasing of NAA concentration. The catharanthine content of C. roseus callus culture was increased by adding NAA as well. The highest catharanthine content was found in 2.5 ppm NAA added callus.

DINGSE PANDIANGAN

2006-09-01

278

N-(7-Methyl-1,8-naphthyridin-2-ylacetamide–acetic acid (1/1  

Directory of Open Access Journals (Sweden)

Full Text Available In the title adduct, C11H11N3O·C2H4O2, all non-H atoms of the acetamide molecule are roughly coplanar, with an r.m.s. deviation of 0.0720?Å. The dihedral angle between the ring plane and the acetamide group is 8.5?(2°. In the crystal, O—H...N and N—H...O hydrogen bonds link the acetamide and acetic acid molecules.

Gao-Zhang Gou

2013-04-01

279

40 CFR 721.2076 - D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...  

Science.gov (United States)

...D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate,...

2010-07-01

280

Antireflectance coating on shielding window glasses using glacial acetic acid at ambient temperature  

International Nuclear Information System (INIS)

High density lead glasses having thickness of several centimeters and large dimensions are used as shielding windows in hot cells. To improve visibility, the reflection of light from its optically polished surfaces needs to be minimized to improve transmission as absorption of light in the thick glasses can not be avoided. Antireflectance coating of a material having low refractive index is required for this purpose. Selective leaching of lead at ambient temperature in glacial acetic acid develops a silica rich leached layer on glass surface. Since silica has low refractive index, the leached layer serves as antireflectance coating. Two optically polished discs of shielding window glasses were leached in glacial acetic acid at ambient temperature for 2, 5 and 10 days and their reflectance and transmittance spectra were taken to find effect of leaching. For transparent glass transmittance could be improved from 78.76% to 85.31% after 10 days leaching. Reflectance from the glass could be decreased from 12.48 to 11.67%. For coloured glass transmittance improved from 87.77% to 88.24% after 5 days leaching while reflectance decreased from 12.28% to 5.6% during same period. Based on data generated, 10 days leaching time is recommended for developing anti reflectance coating on transparent shielding window glass and 5 days for coloured shielding window glass. The procedure can be used for shielding windows of any dimensions by fabrication a PVC tank of slightly high dimensions and filling with acetic acid (author)

2006-01-01

 
 
 
 
281

Utilization of porous dolomite pellets for the catalytic decomposition of acetic acid  

Energy Technology Data Exchange (ETDEWEB)

Catalytic decomposition of tar is a novel technology to clean the gas produced by biomass gasification. The purpose of the present research work was to develop strong and porous pellets of dolomite catalyst for tar decomposition. Porous dolomite pellets of 3 mm in diameter and 4 mm in height were prepared with dolomite, carboxyl methyl cellulose (CMC) and clay. The mechanical strength, the pore rate and the catalytic effect of porous dolomite pellets on decomposition of acetic acid were investigated. When the clay/dolomite mass ratio was 0.4 and the CMC/dolomite mass ratio was 0.2, the porous dolomite pellets had a mechanical strength of 15 N and a pore rate of 0.75 cm{sup 3} g{sup -1}. The pore size had approximately a normal distribution in the range of 0.06-200 {mu}m. Under the condition of gas residence time at 7.5 s and bed temperature at 800 C, 99.7 wt% of acetic acid was decomposed over the porous dolomite pellets, but only 36.5 wt% of acetic acid was decomposed with natural dolomite particles. It was indicated that the porous dolomite pellets were much more effective than the natural dolomite particles for catalyzing the decomposition of tar to gas. (author)

Miao, Yelian; Xue, Jun; Xia, Fajun [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Life Science and Pharmaceutical Engineering, Nanjing University of Technology, NO. 5 Xinmofan Road, Nanjing, Jiangsu 210009 (China); Yin, Xiuli; Wu, Chuangzhi [The Renewable Energy and Gas Hydrate Key Laboratory of CAS, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)

2010-12-15

282

Investigation of acetic acid-catalyzed hydrothermal pretreatment on corn stover  

DEFF Research Database (Denmark)

Acetic acid (AA)-catalyzed liquid hot water (LHW) pretreatments on raw corn stover (RCS) were carried out at 195 °C at 15 min with the acetic acid concentrations between 0 and 400 g/kg RCS. After pretreatment, the liquor fractions and water-insoluble solids (WIS) were collected separately and tested in terms of the recoveries of glucan and xylan from both the liquor fractions and the WIS, toxicity level of the liquors, and the convertibility of WIS to ethanol. The highest glucan recoveries was found to be 97.42% and 97.94% when 15 and 30 g AA/kg RCS were employed, respectively. The highest xylan recovery of 81.82% was observed by the pretreatment with 10 g AA/kg RCS. The toxic test on liquors showed that the inhibition effect happened to Baker's yeast when the acetic acid used in the pretreatment was higher than 100 g/kg RCS. The WIS obtained from the pretreatment with 15 g and 30 g/kg RCS were subjected to enzymatic hydrolysis and more easily converted to ethanol by Baker's yeast, which gave the ethanol concentration of 33.72 g/L and 32.06 g/L, respectively, higher than 22.04 g/L which was from the non-catalyzed LHW pretreatment (195 °C, 15 min). The ethanol concentration from the RCS was only 8.02 g/L.

Xu, Jian; Thomsen, Mette Hedegaard

2010-01-01

283

Kinetics of acetic acid synthesis from ethanol over a Cu/SiO2 catalyst  

DEFF Research Database (Denmark)

The dehydrogenation of ethanol via acetaldehyde for the synthesis of acetic acid over a Cu based catalyst in a new process is reported. Specifically, we have studied a Cu on SiO2 catalyst which has shown very high selectivity to acetic acid via acetaldehyde compared to competing condensation routes. The dehydrogenation experiments were carried out in a flow through lab scale tubular reactor. Based on 71 data sets a power law kinetic expression has been derived for the description of the dehydrogenation of acetaldehyde to acetic acid. The apparent reaction order was 0.89 with respect to water and 0.45 with respect to acetaldehyde, and the apparent activation energy was 33.8kJ/mol. The proposed oxidation of acetaldehyde with hydroxyl in the elementary rate determining step is consistent with these both. Density Functional Theory (DFT) calculations show the preference of water cleavage at the Cu step sites. In light of this, an observed intrinsic activity difference between whole catalyst pellets and crushed pellets may be explained by the Cu crystal size and growth rate being functions of the catalyst particle size and time.

Voss, Bodil; Schjødt, Niels Christian

2011-01-01

284

Mechanical behavior of alumina and alumina-feldspar based ceramics in an acetic acid (4%) environment  

International Nuclear Information System (INIS)

This study investigates the mechanical properties of alumina-feldspar based ceramics when exposed to an aggressive environment (acetic acid 4%). Alumina ceramics containing different concentrations of feldspar (0%, 1%, 5%, 10%, or 40%) were sintered at either 1300, 1600, or 1700 oC. Flaws (of width 0%, 30%, or 50%) were introduced into the specimens using a saw. Half of these ceramic bodies were exposed to acetic acid. Their flexural strength, KIC, and porosity were measured and the fractured samples were evaluated using scanning electronic- and optical microscopy. It was found that in the ceramic bodies sintered at 1600 oC, feldspar content up to 10% improved flexural strength and KIC, and reduced porosities. Generally, it was found that acetic acid had a weakening effect on the flexural strength of samples sintered at 1700 oC but a beneficial effect on KIC of ceramics sintered at 1600 oC. It was concluded that alumina-based ceramics with feldspar content up to 10% and sintered at higher temperatures would perform better in an aggressive environment similar to oral cavity.

2009-12-01

285

Investigation on Ethylenediaminetetra-Acetic Acid as Corrosion Inhibitor for Mild Steel in 1.0M Hydrochloric Acid  

Directory of Open Access Journals (Sweden)

Full Text Available The influence of ethylenediaminetetra-acetic acid (EDTA on the corrosion of mild steel in 1.0 M hydrochloric acid solution was investigated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS. The efficiency of EDTA was compared with thiourea. Primary results obtained revealed that EDTA performed as good corrosion inhibitor for mild steel in 1.0 M hydrochloric acid media comparing with thiourea. Polarization curves show that the behavior of EDTA and thiourea are mixed-type inhibitors. EIS shows that the control step for corrosion process is a charge transfer mechanism.

Ahmed Y. Musa

2009-03-01

286

Analysis of phenolic and indole acetic acids in Meloidogyne graminicola infected rice plants (Oryza sativa L.  

Directory of Open Access Journals (Sweden)

Full Text Available Meloidogyne spp. incite root-knot disease in the roots of Solanaceous and Cereal crop plants inflicting heavy damage to the crops. M. graminicola, a root-knot nematode is ubiquitous as a rice pathogen wherever rice is grown. High Performance Liquid Chromatographic (HPLC analysis of phenolic acids in healthy and root-knot infected plant parts of rice indicated that phenolic acid contents were highly variable in both the cases. Upper leaves of healthy plants had seven phenolic acids in which gallic acid was maximum (140.3 ?g/g fresh wt followed by ferulic, tannic and vanillic acids. However, in root knot-infected plants, upper leaves had six phenolic acids in which gallic acid was maximum (190.68 ?g followed by caffeic, ferulic, o-coumeric, cinnamic and salicylic acids. In healthy leaf sheath gallic acid was the maximum (8.6 ?g followed by tannic, ferulic, vanillic, caffeic acid but o-coumeric, cinnamic and Indole Acetic Acid (IAA were detected in traces. Root knot-infected leaf sheath had nine phenolic acids, where gallic was the maximum (26.84 ?g followed by vanillic, ferulic, o-coumeric and tannic acids but other phenolic acids, viz., cinnamic, salicylic and IAA were present in traces. Roots of healthy rice plants had seven phenolic acids while infected roots had nine phenolic acids. Moreover, in infected roots without root-knot had eight phenolic acids, in which gallic was the maximum (29.30 ?g followed by ferulic, caffeic, vanillic, tannic and o-coumeric acids but salicylic and IAA were present in traces.

Amitabh Singh

2013-08-01

287

Removal of fluoride in aqueous solution by adsorption on acid activated water treatment sludge  

Science.gov (United States)

This paper reports the use of a pellet of adsorbent made from water treatment sludge (S) and acid activated water treatment sludge (SH) for removal of fluoride in the batch equilibration technique. The influence of pH, adsorbent dosage, temperature and effect of other ions were employed to find out the feasibility of acid activated adsorbent to remove fluoride to the permissible concentration of 0.7 mg/L. The results from the adsorption isotherm followed both Langmuir and Freundlich models and the highest fluoride removal was found for adsorbent activated with acetic acid at 2.0 mol/L. The optimum adsorbent dosage was found at 40 g/L, 0.01 mol/L acid activated adsorbent which was able to adsorb fluoride from 10 down to 0.11 mg/L. The adsorption capacity was decreased when the temperature increased. This revealed that the adsorption of fluoride on SH was exothermic. In the presence of nitrate and carbonate ions in the aqueous solution, fluoride removal efficiency of SH decreased from 94.4% to 86.6% and 90.8%, respectively. However, there is no significant effect in the presence of sulfate and chloride ions.

Vinitnantharat, Soydoa; Kositchaiyong, Sriwilai; Chiarakorn, Siriluk

2010-06-01

288

Low energy electron diffraction (LEED) study of the adsorption of acetic acid and propanoic acid on Ag(111) and Pt(111)  

International Nuclear Information System (INIS)

The adsorption of acetic acid and of propanoic acid on Ag(111) and Pt(111) single crystal surfaces has been studied with LEED. Both acetic acid and propanoic acid formed two-dimensional structures in two different types of orientation on Ag(111) and propanoic acid apparently formed the same structure on graphite covered Pt(111). Neither acid formed ordered monolayers when adsorbed on clean Pt(111). The similar LEED data and physical properties of the acid molecules suggested similar structures for both acids consisting of closely packed arrays of hydrogen-bonded dimers

1980-01-01

289

Vibrational spectra of crystalline formic and acetic acid isotopologues by inelastic neutron scattering and numerical simulations  

International Nuclear Information System (INIS)

Vibrational spectra of crystalline powder of four isotopologues of formic acid (HCOOH, HCOOD, DCOOH, DCOOD) and of acetic acid (CH3COOH, CH3COOD, CD3COOH, CD3COOD) were recorded at 20 K by inelastic neutron scattering. These spectra are compared with computed spectra based on harmonic force fields derived from periodic density functional theory (DFT) calculations. The assignment of all internal vibrations is obvious from the spectral changes under isotopic substitution. Discrepancies between calculation and experiment expose the over evaluation of the strength of the hydrogen bond by these standard DFT calculations

2009-01-27

290

Characterization of acetic acid bacteria in traditional acetic acid fermentation of rice vinegar (komesu) and unpolished rice vinegar (kurosu) produced in Japan.  

Science.gov (United States)

Bacterial strains were isolated from samples of Japanese rice vinegar (komesu) and unpolished rice vinegar (kurosu) fermented by the traditional static method. Fermentations have never been inoculated with a pure culture since they were started in 1907. A total of 178 isolates were divided into groups A and B on the basis of enterobacterial repetitive intergenic consensus-PCR and random amplified polymorphic DNA fingerprinting analyses. The 16S ribosomal DNA sequences of strains belonging to each group showed similarities of more than 99% with Acetobacter pasteurianus. Group A strains overwhelmingly dominated all stages of fermentation of both types of vinegar. Our results indicate that appropriate strains of acetic acid bacteria have spontaneously established almost pure cultures during nearly a century of komesu and kurosu fermentation. PMID:11157275

Nanda, K; Taniguchi, M; Ujike, S; Ishihara, N; Mori, H; Ono, H; Murooka, Y

2001-02-01

291

Acetic Acid Activates the AMP-Activated Protein Kinase Signaling Pathway to Regulate Lipid Metabolism in Bovine Hepatocytes  

Science.gov (United States)

The effect of acetic acid on hepatic lipid metabolism in ruminants differs significantly from that in monogastric animals. Therefore, the aim of this study was to investigate the regulation mechanism of acetic acid on the hepatic lipid metabolism in dairy cows. The AMP-activated protein kinase (AMPK) signaling pathway plays a key role in regulating hepatic lipid metabolism. In vitro, bovine hepatocytes were cultured and treated with different concentrations of sodium acetate (neutralized acetic acid) and BML-275 (an AMPK? inhibitor). Acetic acid consumed a large amount of ATP, resulting in an increase in AMPK? phosphorylation. The increase in AMPK? phosphorylation increased the expression and transcriptional activity of peroxisome proliferator-activated receptor ?, which upregulated the expression of lipid oxidation genes, thereby increasing lipid oxidation in bovine hepatocytes. Furthermore, elevated AMPK? phosphorylation reduced the expression and transcriptional activity of the sterol regulatory element-binding protein 1c and the carbohydrate responsive element-binding protein, which reduced the expression of lipogenic genes, thereby decreasing lipid biosynthesis in bovine hepatocytes. In addition, activated AMPK? inhibited the activity of acetyl-CoA carboxylase. Consequently, the triglyceride content in the acetate-treated hepatocytes was significantly decreased. These results indicate that acetic acid activates the AMPK? signaling pathway to increase lipid oxidation and decrease lipid synthesis in bovine hepatocytes, thereby reducing liver fat accumulation in dairy cows.

Li, Xinwei; Chen, Hui; Guan, Yuan; Li, Xiaobing; Lei, Liancheng; Liu, Juxiong; Yin, Liheng; Liu, Guowen; Wang, Zhe

2013-01-01

292

Bioethanol production from lignocellulosics with hot-compressed water treatment followed by acetic acid fermentation and hydrogenolysis  

Energy Technology Data Exchange (ETDEWEB)

This presentation described a newly developed ethanol production system which involves hot-compressed water treatment combined with acetic acid fermentation and catalytic hydrogenation. The hot-compressed water treatment was optimized by using a semi-flow treatment on Japanese beech wood at 230 degrees C/10 MPa for 15 min, and then at 270 degrees C/10 MPa for 15 min. Under these conditions, 54 per cent of the hemicelluloses and 71 wt per cent of the cellulose were hydrolyzed, respectively. However, approximately 12 wt per cent of the wood decomposed into dehydrated and fragmented products. Approximately 88 per cent of the lignin also decomposed. The fermentability of these various compounds to acetic acid was then examined. Monosaccharides as well as some decomposed compounds and lignin-derived compounds were all found to be fermentable to acetic acid with Clostridium thermoaceticum. In particular, glucose, xylose and fructose could be effectively converted to acetic acid with a 70 to 80 per cent yield. Oligosaccharides and polysaccharides were converted with C. thermocellum to glucose and organic acids. Almost all compounds obtained by the hot-compressed water treatment were converted to acetic acid in co-culture fermentation. A flow-type laboratory reactor was used to evaluate ethanol production from acetic acid using a one-step hydrogenation method to ethanol. A very dilute aqueous solution of acetic acid was effectively hydrogenated to ethanol. It was concluded that compared to conventional yeast fermentation, ethanol can be produced more efficiently from lignocellulosics by combining the 3 steps of hot-compressed water treatment followed by acetic acid fermentation and hydrogenation.

Saka, S.; Phaiboonsilpa, N.; Nakamura, Y.; Masuda, S.; Lu, X.; Yamauchi, K.; Miyafuji, H.; Kawamoto, H. [Kyoto Univ., Kyoto (Japan)

2009-07-01

293

Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA. Acetic acid is an important intermediate in aqueous methylglyoxal oxidation and a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. Altieri et al. (2008 proposed that acetic acid was the precursor of oligoesters observed in methylglyoxal oxidation. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid at concentrations relevant to atmospheric waters (20 ?M–10 mM was oxidized by OH radical. Products were analyzed by ion chromatography (IC, electrospray ionization mass spectrometry (ESI-MS, and IC-ESI-MS. The formation of glyoxylic, glycolic, and oxalic acids were observed. In contrast to methylglyoxal oxidation, succinic acid and oligomers were not detected. Using results from these and methylglyoxal + OH radical experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

Y. Tan

2011-06-01

294

Partition coefficients for acetic, propionic, and butyric acids in a crude oil/water system  

Energy Technology Data Exchange (ETDEWEB)

The effects of pH, temperature, and organic acid concentration on the partition coefficients for short-chain organic acids were measured in a crude oil/water system. Acetic, propionic, and butyric acids, as probable substrates for microbial souring of oil reservoirs, were used in conjunction with two types of crude oil. Temperatures of 35--75 C, pH values of 4.0--7.0, and acid concentrations of 10--1,000 mg/L were studied. Initial naturally occurring levels of organic acids in the crude oils were also determined. pH had by far the largest effect on the partition coefficient for all three organic acids for both types oil. At conditions normally seen in an oil reservoir (pH 5--7), the great percentage (85+%) of these acids were dissolved in the aqueous phase. The log of the partition coefficient K increased approximately linearly with the number of carbon atoms in the acid. It was seen that organic acids are readily available carbon sources for sulfate-reducing bacteria (SRB) at normal reservoir conditions, and that crude oil may provide a source of organic acids in a low-pH, water-flooded reservoir.

Reinsel, M.A.; Borkowski, J.J.; Sears, J.T. (Montana State Univ., Bozeman, MT (United States). National Science Foundation Engineering Research Center for Biofilm Engineering)

1994-07-01

295

INHIBITION OF NEURAL CREST CELL MIGRATION BY THE WATER DISINFECTION BYPRODUCTS DICHLORO-, DIBROMO-, AND BROMOCHLORO-ACETIC ACID.  

Science.gov (United States)

INHIBITION OF NEURAL CREST CELL MIGRATION BY THE WATER DISINFECTION BYPRODUCTS DICHLORO-, DIBROMO- AND BROMOCHLORO-ACETIC ACID. JE Andrews, H Nichols, J Schmid 1, and ES Hunter. Reproductive Toxicology Division, 1Research Support Division, NHEERL, USEPA, RTP, NC, USA. ...

296

Synthesis of methyl acetate from dimethyl ether using group VIII metal salts of phosphotungstic acid  

Energy Technology Data Exchange (ETDEWEB)

Dimethyl ether (DME) can be produced much more efficiently in a single-stage, liquid-phase process from natural gas-based syngas as compared to the conventional process via dehydration of methanol. This process, based on dual catalysts slurried in inert oil, alleviates the chemical equilibrium limitation governing the methanol synthesis reaction and concurrently improves per-pass syngas conversion and reactor productivity. The potential, therefore, for production of methyl acetate via dimethyl ether carbonylation is of industrial importance. In the present study, conversion of dimethyl ether and carbon monoxide to methyl acetate is investigated over a variety of group VIII metal-substituted phosphotungstic acid salts. Experimental results of this catalytic reaction using rhodium, iridium, ruthenium, and palladium catalysts are evaluated and compared in terms of selectivity toward methyl acetate. The effects of active metal, support types, multiple metal loading, and feed conditions on carbonylation activity of DME are examined. Iridium metal substituted phosphotungstic acid supported on Davisil type 643 (pore size 150 A, surface area 279 m{sup 2}/g, mesh size 230-425) silica gel shows the highest activity for DME carbonylation. (author)

Sardesai, A.; Lee, S.; Tartamella, T.

2002-04-01

297

Sources and sinks of formic, acetic, and pyruvic acids over central Amazonia. II - Wet season  

Science.gov (United States)

Potential sources and sinks of formic, acetic, and pyruvic acids over the Amazon forest were investigated using a photochemical model and data collected on gas phase concentrations of these acids in the forest canopy, boundary layer, and free troposphere over the central Amazon Basin during the 1987 wet season. It was found that the atmospheric reactions previously suggested in the literature as sources of carboxylic acids (i.e., the gas phase decomposition of isoprene, the reaction between CH3CO3 and a peroxide, and aqueous phase oxidation of CH2O) appear to be too slow to explain the observed concentrations, suggesting that other atmospheric reactions, so far unidentified, could make a major contribution to the carboxylic acid budgets.

Talbot, R. W.; Andreae, M. O.; Berresheim, H.; Jacob, D. J.; Beecher, K. M.

1990-01-01

298

Bimodal electricity generation and aromatic compounds removal from purified terephthalic acid plant wastewater in a microbial fuel cell.  

Science.gov (United States)

Wastewater of purified terephthalic acid (PTA) from a petrochemical plant was examined in a membrane-less single chamber microbial fuel cell for the first time. Time course of voltage during the cell operation cycle had two steady phases, which refers to the fact that metabolism of microorganisms was shifted from highly to less biodegradable carbon sources. The produced power density was 31.8 mW m(-2) (normalized per cathode area) and the calculated coulombic efficiency was 2.05 % for a COD removal of 74 % during 21 days. The total removal rate of different pollutants in the PTA wastewater was observed in the following order: (acetic acid) > (benzoic acid) > (phthalic acid) > (terephthalic acid) > (p-toluic acid). The cyclic voltammetry results revealed that the electron transfer mechanism was dominated by mediators which were produced by bacteria. PMID:23076363

Marashi, Seyed Kamran Foad; Kariminia, Hamid-Reza; Savizi, Iman Shahidi Pour

2013-02-01

299

Radiolabeled acetate as a tracer of myocardial tricarboxylic acid cycle flux  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of (1-14C)acetate oxidation in isolated perfused rat hearts have been determined over a range of perfusion conditions. Effluent measurements demonstrated that 14CO2 cleared biexponentially over 50 minutes after bolus injection of (1-14C)acetate into normoxic hearts perfused with 5 mM glucose and 10 mU/ml insulin. The clearance half-time (t1/2) for the predominant initial clearance phase was 3.1 +/- 0.5 minutes (n = 4). MVO2 was varied over a fourfold range by hypoxia and phenylephrine stimulation (t1/2, 7.2 +/- 1.2 and 2.2 +/- 0.2 minutes, respectively) and in the presence of alternate substrates (lactate, 2 mM; DL-3-hydroxybutyrate, 20 mM; and palmitate, 0.1 mM), which did not modify either tricarboxylic acid (TCA) cycle flux or acetate kinetics. A good correlation (r = 0.93) was observed between k, the rate constant for the initial phase of 14CO2 clearance, and TCA cycle flux, estimated from oxygen consumption. In contrast to results with (1-14C)acetate, lactate (2 mM) increased t1/2 for 14CO2 clearance from a bolus injection of (1-14C)palmitate from 3.0 +/- 0.4 minutes (n = 3) at control to 4.3 +/- 0.2 minutes (n = 3, p less than 0.01). Addition of acetate in nontracer amounts (0.5 or 5 mM) caused significant underestimation of TCA cycle flux when estimated with (1-14C)acetate. 14CO2 clearance accounted for 88-98% of total effluent 14C between 10 and 20 minutes after (1-14C)acetate bolus injection; rate constants for clearance of 14CO2 and total 14C clearance were very similar during this period, and these two rate constants did not differ significantly from each other under any conditions tested.

Buxton, D.B.; Schwaiger, M.; Nguyen, A.; Phelps, M.E.; Schelbert, H.R.

1988-09-01

300

Radiolabeled acetate as a tracer of myocardial tricarboxylic acid cycle flux  

International Nuclear Information System (INIS)

The kinetics of [1-14C]acetate oxidation in isolated perfused rat hearts have been determined over a range of perfusion conditions. Effluent measurements demonstrated that 14CO2 cleared biexponentially over 50 minutes after bolus injection of [1-14C]acetate into normoxic hearts perfused with 5 mM glucose and 10 mU/ml insulin. The clearance half-time (t1/2) for the predominant initial clearance phase was 3.1 +/- 0.5 minutes (n = 4). MVO2 was varied over a fourfold range by hypoxia and phenylephrine stimulation (t1/2, 7.2 +/- 1.2 and 2.2 +/- 0.2 minutes, respectively) and in the presence of alternate substrates (lactate, 2 mM; DL-3-hydroxybutyrate, 20 mM; and palmitate, 0.1 mM), which did not modify either tricarboxylic acid (TCA) cycle flux or acetate kinetics. A good correlation (r = 0.93) was observed between k, the rate constant for the initial phase of 14CO2 clearance, and TCA cycle flux, estimated from oxygen consumption. In contrast to results with [1-14C]acetate, lactate (2 mM) increased t1/2 for 14CO2 clearance from a bolus injection of [1-14C]palmitate from 3.0 +/- 0.4 minutes (n = 3) at control to 4.3 +/- 0.2 minutes (n = 3, p less than 0.01). Addition of acetate in nontracer amounts (0.5 or 5 mM) caused significant underestimation of TCA cycle flux when estimated with [1-14C]acetate. 14CO2 clearance accounted for 88-98% of total effluent 14C between 10 and 20 minutes after [1-14C]acetate bolus injection; rate constants for clearance of 14CO2 and total 14C clearance were very similar during this period, and these two rate constants did not differ significantly from each other under any conditions tested

1988-01-01

 
 
 
 
301

The integration of acetic acid iontophoresis, orthotic therapy and physical rehabilitation for chronic plantar fasciitis: a case study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A 15-year-old female soccer player presented with chronic plantar fasciitis. She was treated with acetic acid iontophoresis and a combination of rehabilitation protocols, ultrasound, athletic taping, custom orthotics and soft tissue therapies with symptom resolution and return to full activities within a period of 6 weeks. She reported no significant return of symptoms post follow-up at 2 months. Acetic acid iontophoresis has shown promising results and further studies should be considered to...

Costa, Ivano A.; Dyson, Anita

2007-01-01

302

Acetic acid inhibits nutrient uptake in Saccharomyces cerevisiae: auxotrophy confounds the use of yeast deletion libraries for strain improvement.  

Science.gov (United States)

Acetic acid inhibition of yeast fermentation has a negative impact in several industrial processes. As an initial step in the construction of a Saccharomyces cerevisiae strain with increased tolerance for acetic acid, mutations conferring resistance were identified by screening a library of deletion mutants in a multiply auxotrophic genetic background. Of the 23 identified mutations, 11 were then introduced into a prototrophic laboratory strain for further evaluation. Because none of the 11 mutations was found to increase resistance in the prototrophic strain, potential interference by the auxotrophic mutations themselves was investigated. Mutants carrying single auxotrophic mutations were constructed and found to be more sensitive to growth inhibition by acetic acid than an otherwise isogenic prototrophic strain. At a concentration of 80 mM acetic acid at pH 4.8, the initial uptake of uracil, leucine, lysine, histidine, tryptophan, phosphate, and glucose was lower in the prototrophic strain than in a non-acetic acid-treated control. These findings are consistent with two mechanisms by which nutrient uptake may be inhibited. Intracellular adenosine triphosphate (ATP) levels were severely decreased upon acetic acid treatment, which likely slowed ATP-dependent proton symport, the major form of transport in yeast for nutrients other than glucose. In addition, the expression of genes encoding some nutrient transporters was repressed by acetic acid, including HXT1 and HXT3 that encode glucose transporters that operate by facilitated diffusion. These results illustrate how commonly used genetic markers in yeast deletion libraries complicate the effort to isolate strains with increased acetic acid resistance. PMID:23828602

Ding, Jun; Bierma, Jan; Smith, Mark R; Poliner, Eric; Wolfe, Carole; Hadduck, Alex N; Zara, Severino; Jirikovic, Mallori; van Zee, Kari; Penner, Michael H; Patton-Vogt, Jana; Bakalinsky, Alan T

2013-08-01

303

Mutants of the pentose-fermenting yeast Pachysolen tannophilus tolerant to hardwood spent sulfite liquor and acetic acid.  

Science.gov (United States)

A strain development program was initiated to improve the tolerance of the pentose-fermenting yeast Pachysolen tannophilus to inhibitors in lignocellulosic hydrolysates. Several rounds of UV mutagenesis followed by screening were used to select for mutants of P. tannophilus NRRL Y2460 with improved tolerance to hardwood spent sulfite liquor (HW SSL) and acetic acid in separate selection lines. The wild type (WT) strain grew in 50 % (v/v) HW SSL while third round HW SSL mutants (designated UHW301, UHW302 and UHW303) grew in 60 % (v/v) HW SSL, with two of these isolates (UHW302 and UHW303) being viable and growing, respectively, in 70 % (v/v) HW SSL. In defined liquid media containing acetic acid, the WT strain grew in 0.70 % (w/v) acetic acid, while third round acetic acid mutants (designated UAA301, UAA302 and UAA303) grew in 0.80 % (w/v) acetic acid, with one isolate (UAA302) growing in 0.90 % (w/v) acetic acid. Cross-tolerance of HW SSL-tolerant mutants to acetic acid and vice versa was observed with UHW303 able to grow in 0.90 % (w/v) acetic acid and UAA302 growing in 60 % (v/v) HW SSL. The UV-induced mutants retained the ability to ferment glucose and xylose to ethanol in defined media. These mutants of P. tannophilus are of considerable interest for bioconversion of the sugars in lignocellulosic hydrolysates to ethanol. PMID:24122119

Harner, Nicole K; Bajwa, Paramjit K; Habash, Marc B; Trevors, Jack T; Austin, Glen D; Lee, Hung

2014-01-01

304

Stiffening agent for cotton woven fabrics from (Methacrylic Acid/Vinyl Acetate/Methylacrylate) Terpolymer  

International Nuclear Information System (INIS)

The emulsion polymerizations of (Methacrylic acid-co-vinyl acetate co- methylacrylate) terpolymer in different vinyl acetate/methylacrylate molar ratios were carried out using sodium dodecyl sulphate (SDS) as emulsifier and K2S2O8 as initiator at 70 degree C for 6 hours in semicontinuous reaction mode. The molecular weights and the molecular weights distributions were determined using Gel permeation chromatography. All terpolymers prepared showed mono modal molecular weight polymdispersity indices around 4. Tg s and thermal stability of the prepared terpolymers were determined using DSC and TGA respectively. The elongation at rupture and tensile strength were determined as functions of the molar composition in the emulsion feed. The terpolymers prepared were tested as stiffening agents for the polyester and cotton woven fabrics. The effect of molar composition in the emulsion feed upon the stiffening efficiency was discussed

2005-11-27

305

Thermodynamic analysis of vapor- liquid equilibrium for (water-acrylic acid) and (acetic acid-acrylic acid) systems at moderate pressure  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, experimental vapor-liquid equilibria data for two binary systems {water + acrylic acid} and {acetic acid + acrylic acid} are determined at low pressure by ebulliometer apparatus. Our experimental data are also in good agreement with those published in the literature. The vapor-liquid equilibria of binary systems are represented using NRTL-HOC and UNIQUAC-HOC models. A good quantitative agreement was obtained with both models. It was found that the average deviation from the NRT...

2012-01-01

306

Synthesis and evaluation of mutual azo prodrug of 5-aminosalicylic acid linked to 2-phenylbenzoxazole-2-yl-5-acetic acid in ulcerative colitis  

Directory of Open Access Journals (Sweden)

Full Text Available Jamal A Jilani,1 Maha Shomaf,2 Karem H Alzoubi3 1Department of Medicinal Chemistry and Pharmacognosy, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Pathology, Jordan University, Amman, Jordan; 3Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, Jordan Abstract: In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID] and 5-[4-(benzoxazol-2-yl-5-acetic acidphenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA] are reported. The structures of the synthesized compounds were confirmed using infrared (IR, hydrogen-1 nuclear magnetic resonance (1H NMR, and mass spectrometry (MS spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis. Keywords: benzoxazole acetic acid, azo prodrug, colon drug delivery

Jilani JA

2013-07-01

307

Okadaic acid: An additional non-phorbol-12-tetradecanoate-13-acetate-type tumor promoter  

International Nuclear Information System (INIS)

Okadaic acid is a polyether compound of a C38 fatty acid, isolated from a black sponge, Halichondria okadai. Previous studies showed that okadaic acid is a skin irritant and induces ornithine decarboxylase in mouse skin 4 hr after its application to the skin. This induction was strongly inhibited by pretreatment of the skin with 13-cis-retinoic acid. A two-stage carcinogenesis experiment in mouse skin initiated by a single application of 100 ?g of 7,12-dimethylbenz[a]anthracene (DMBA) and followed by application of 10 ?g of okadaic acid twice a week revealed that okadaic acid is a potent additional tumor promoter: tumors developed in 93% of the mice treated with DMBA and okadaic acid by week 16. In contrast, tumors were found in only one mouse each in the groups treated with DMBA alone or okadaic acid alone. An average of 2.6 tumors per mouse was found in week 30 in the group treated with DMBA and okadaic acid. Unlike phorbol 12-tetradecanoate 13-acetate (TPA), teleocidin, and aplysiatoxin, okadaic acid did not inhibit the specific binding of [3H]TPA to a mouse skin particulate fraction when added up to 100 ?M or activate calcium-activated, phospholipid-dependent protein kinase (protein kinase C) in vitro when added up to 1.2 ?M. Therefore, the actions of okadaic acid and phorbol ester may be mediated in different ways. These results show that okadaic acid is a non-TPA-type tumor promoter in mouse skin carcinogenesis

1988-01-01

308

Toxicokinetics and Oral Bioavailability of Halogenated Acetic Acids Mixtures in Naive and GSTzeta-Depleted Rats  

Energy Technology Data Exchange (ETDEWEB)

Pharmacokinetics of halogenated acetic acid (HAA) mixtures in native and GSTzeta depleted rats was investigated. Rats were administered orally or i.v. to Mixture-1 (monobromo- dichloro-, chlorodibromo-, tribromo- acetic acids) or Mixture-2 (bromochloro-, dibromo-, trichloro- bromodichloro- acetic acids) at a dose of 25 ?mol/kg HAA and blood samples collected up to 36 h. GSTzeta depleted rats were also orally dosed with each mixture and euthanized at 0.25, 0.5, 1, 2 and 4 h to determine tissue distribution. In Mixture-1, GSTzeta depletion only affected the pharmacokinetics of DCAA, which increased the elimination t? from 9 min to 1.3 h. After oral administration, DCAA exhibited a complex time-course plasma profile with secondary peaks appearing long after completion of the initial absorption phase. This phenomenon coincided with elevated DCA levels in the lower portion of the GI tract compared to CDBAA and TBAA. For Mixture-2, all di-HAAs were eliminated extremely rapidly from plasma in both na?ve and GSTzeta depleted animals (t? was 4-11 min in na?ve and 11-24 min in GSTzeta depleted rats), t? of BDCAA and TCAA was 3.5 and 12 h in na?ve and 2.3 and 7.5 h in GSTzeta depleted rats. The primary difference in the pharmacokinetics among HAAs when administered as mixture was the total body clearance (Clb) which was reduced compared to after individual administration. These results suggest competitive interactions between tri- and di-HAAs beyond what would be predicted from individual HAA studies. For di-HAAs, the total dose is important as clearance is dose dependent due to competition for GSTzeta. When considering HAAs dosimetry, importance should be placed on both the components of the mixture and prior exposure history to di-HAAs.

Saghir, Shakil A.; Schultz, Irv R.

2005-04-01

309

Nitration of hexamethylbenzene and hexamethylbenzene-d18 in acetic acid  

International Nuclear Information System (INIS)

The reaction in acetic acid of hexamethylbenzene and hexamethylbenzene-d18 with nitric acid in the dark has been investigated under various conditions using a high-pressure liquid chromatographic method. Pentamethylbenzyl nitrate, pentamethylphenylnitromethane, pentamethylbenzyl acetate, and pentamethylbenzyl alcohol were formed immediately after the mixing of reactants; their relative amounts remained almost unchanged up to nearly 50% conversion. The addition of sodium nitrite gave little influence on the composition of the product mixture, while urea was found to depress somewhat the formation of nitromethane. In the presence of lithium nitrate, the reaction was modestly accelerated and the nitrate formation seems to be slightly favored over the nitromethane formation. Hexamethylbenzene-d18 reacted with nitric acid at the same rate as the non-labeled hydrocarbon did, but the benzyl nitrate/phenylnitromethane ratio in the product mixture was considerably higher in the former. Based on the quantitative data obtained, the mechanism for the side-chain substitution has been discussed in terms of the S sub( n)1' pathway: nitronium ion makes an ipso attack on the substrate to form the arenium ion, which releases a proton from the activated methyl group para to the site of attack to give the 3-methylene-6-nitro-1,4-cyclohexadiene intermediate (7). Heterolytic fission of the C-N bond in 7 will form a benzyl cation-nitrite anion pair, which recombines at the benzylic carbon atom via a C-N bond or via a C-O bond, giving benzyl nitrite or phenylnitromethane, respectively. Benzyl nitrite will be further converted into benzyl nitrate and benzyl alcohol, while benzyl acetate will arise from the incorporation of solvent molecules into the ion-pair. (author)

1979-01-01

310

Removing naphthenic acids from light petroleum products with reagent regeneration  

Energy Technology Data Exchange (ETDEWEB)

The results are cited of a study of the removal of naphthenic acids from light petroleum products with an ammonia solution with subsequent regeneration of the reagent for creating a circular process. The optimal conditions are found for purifying distillates of diesel fuels, conducted in a combined, two section reaction and extraction tower, and the conditions for regenerating the ammonia and for separating the raw acids from aqueous solutions of ammonia salts of naphthenic acids.

Agayev, A.A.; Khachaturova, I.K.; Kurbanaliyev, T.G.

1983-01-01

311

A new polymorph of 2-(2H-benzotriazol-2-yl)acetic acid  

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A new polymorph of 2-(benzotriazol-2-yl)acetic acid, C8H7N3O2, crystallizes in the space group C2/c (Z = 8). The non-planar molecule has a synplanar conformation of the carboxy group. The crystal structure features helices parallel to the b axis sustained by O—H...N hydrogen bonding which are similar to those in the known polymorph [Giordano & Zagari (1978). J. Chem. Soc. Perkin Trans. 2, pp. 312–315]. However, in the title structure, columns are formed by ?–? ...

Guloy Alieva; Jamshid Ashurov; Nasir Mukhamedov; Nusrat Parpiev

2012-01-01

312

Measurement of glomerular filtration rate in children using technetium-99m diethylenetriamine penta-acetic acid  

International Nuclear Information System (INIS)

During the past 5 years, we have measured the glomerular filtration rate (GFR) by the slope-clearance method using technetium-99m diethylenetriamine penta-acetic acid technetium-99m-DTPA in 130 infants and children. The results in 22 children have been compared with inulin clearance, and a very good correlation between the two methods of measurement of GFR was demonstrated (r = 0,9616; P less than 0,0001). This study provides further evidence that technetium-99m-DTPA is a satisfactory agent for the clinical measurement of GFR in children

1985-03-30

313

Electrogeneration of iodine (1) from methyl iodide in acetic acid for application in coulometric analysis  

International Nuclear Information System (INIS)

Conditions of electrochemical preparation of I(1) from methyl iodide in acetic acid are found. The I(1) current efficiency is close to 100% at current densities from 1.1 up to 3.3 mA/cm"2. The actual redox potential of the I(1)/CH_3I system in HAc is 1.186+-0.001 V. The scheme of two-electron electrochemical CH_3I oxidation is proposed. The electrogenerated I(1) is used for electrochemical iodination of some organic compounds for the coulometric analysis

1985-08-01

314

Response to flavone acetic acid (NSC 347512) of primary and metastatic human colorectal carcinoma xenografts.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The antitumour activity of flavone acetic acid (FAA) was evaluated against two human colorectal carcinoma (HCC) lines, HCC-P2988 and HCC-M1410, transplanted into nude mice. On repeated i.v. injection of 200 mg kg-1 every 4 days FAA was moderately active against the s.c. growing HCC-P2988. HCC-M1410 transplanted s.c. was almost unresponsive in the same experimental conditions. In contrast, FAA (200 mg kg-1 i.v. every 4 days, repeated three times) significantly reduced liver tumour colonies pro...

Giavazzi, R.; Garofalo, A.; Damia, G.; Garattini, S.; D Incalci, M.

1988-01-01

315

Calorimetric study of deuterium isotope effects in water-acetic acid systems  

International Nuclear Information System (INIS)

The molar excess enthalpies of water-acetic acid systems are analysed to give the enthalpy of the reaction 2HA(1)+D_2O(1) ?2DA(1)+H_2O(1) (A = CH_3COO or CD_3COO) The value obtained at 298 K is -0.15+-0.04 kJ mol"-"1. Molar excess enthalpies at 298.15 K are reported for the systems H_2O+CH_3 COOH, H_2O+CD_3COOD, D_2O+CH_3COOH and D_2O+CD_3COOD

1980-11-01

316

Hydroxylamine hydrochloride-acetic acid-soluble and -insoluble fractions of pelagic sediment: Readsorption revisited  

Science.gov (United States)

The extraction of the rare earth elements (REE) from deep-ocean pelagic sediment, using hydroxylamine hydrochloride-acetic acid, leads to the separation of approximately 70% of the bulk REE content into the soluble fraction and 30% into the insoluble fraction. The REE pattern of the soluble fraction, i.e., the content of REE normalized to average shale on an element-by-element basis and plotted against atomic number, resembles the pattern for seawater, whereas the pattern, as well as the absolute concentrations, in the insoluble fraction resembles the North American shale composite. These results preclude significant readsorption of the REE by the insoluble phases during the leaching procedure.

Piper, D. Z.; Wandless, G. A.

1992-01-01

317

2-[2-(1,3-Dioxoisoindolin-2-ylacetamido]acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available The title molecule, C12H10N2O5, is non-planar with dihedral angles of 89.08?(7 and 83.21?(7° between the phthalimide and acetamide mean planes, and the acetamide and acetic acid mean planes, respectively. In the crystal, symmetry-related molecules are linked via N—H...O and O—H...O hydrogen bonds, forming an undulating two-dimensional network. There are also a number of weak C—H...O interactions, leading to the formation of a three-dimensional arrangement.

Moazzam H. Bhatti

2010-11-01

318

Effects of sorption on biological degradation rates of (2,4-dichlorophenoxy) acetic acid in soils.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Three mathematical models were proposed to describe the effects of sorption of both bacteria and the herbicide (2,4-dichlorophenoxy)acetic acid (2,4-D) on the biological degradation rates of 2,4-D in soils. Model 1 assumed that sorbed 2,4-D is not degraded, that only bacteria in solution are capable of degrading 2,4-D in solution, and that sorbed bacteria are not capable of degrading either sorbed or solution 2,4-D. Model 2 stated that only bacteria in the solution phase degrade 2,4-D in solu...

Ogram, A. V.; Jessup, R. E.; Ou, L. T.; Rao, P. S.

1985-01-01

319

(Liquid + liquid) equilibria of the (water + acetic acid + dibutyl phthalate) system  

International Nuclear Information System (INIS)

(Liquid + liquid) equilibrium (LLE) data of the (water + acetic acid + dibutyl phthalate) system have been determined experimentally at T = (298.2, 308.2, and 318.2) K. The reliability of the experimental tie lines data was ascertained by using the Othmer-Tobias correlation. The UNIFAC model was used to predict the phase equilibrium in the system using the interaction parameters between AC, ACH, CH2, CH3, CH2COO, COOH, and H2O functional groups. The experimental data were compared with predicted by UNIFAC model. Distribution coefficients and separation factors were evaluated for the immiscibility region

2005-11-01

320

Simultaneous determination of 2-naphthoxyacetic acid and indole-3-acetic acid by first derivation synchronous fluorescence spectroscopy  

Science.gov (United States)

A simple, rapid, sensitive and selective method for simultaneously determining 2-naphthoxyacetic acid (BNOA) and Indole-3-Acetic Acid (IAA) in mixtures has been developed using derivation synchronous fluorescence spectroscopy based on their synchronous fluorescence. The synchronous fluorescence spectra were obtained with ?? = 100 nm in a pH 8.5 NaH2PO4-NaOH buffer solution, and the detected wavelengths of quantitative analysis were set at 239 nm for BNOA and 293 nm for IAA respectively. The over lapped fluorescence spectra were well separated by the synchronous derivative method. Under optimized conditions, the limits of detection (LOD) were 0.003 ?g/mL for BNOA and 0.012 ?g/mL for IAA. This method is simple and expeditious, and it has been successfully applied to the determination of 2-naphthoxyacetic acid and indole-3-acetic acid in fruit juice samples with satisfactory results. The samples were only filtrated through a 0.45 ?m membrane filter, which was free from the tedious separation procedures. The obtaining recoveries were in the range of 83.88-87.43% for BNOA and 80.76-86.68% for IAA, and the relative standard deviations were all less than 5.0%. Statistical comparison of the results with high performance liquid chromatography Mass Spectrometry (HPLC-MS) method revealed good agreement and proved that there were no significant difference in the accuracy and precision between these two methods.

Liu, Xiangxiang; Wan, Yiqun

2013-07-01

 
 
 
 
321

Liquid phase equilibria of (water + phosphoric acid + 1-butanol or butyl acetate) ternary systems at T = 308.2 K  

Energy Technology Data Exchange (ETDEWEB)

(Liquid + liquid) equilibria and tie lines for the ternary systems of (water + phosphoric acid + 1-butanol) and (water + phosphoric acid + butyl acetate) were measured at T = 308.2 K. The experimental ternary (liquid + liquid) equilibrium data were correlated with the UNIQUAC model. The reliability of the experimental tie lines was confirmed using Othmer-Tobias correlation. The average root-mean-square deviation (RMSD) values of (water + phosphoric acid + 1-butanol) and (water + phosphoric acid + butyl acetate) systems were 2.17% and 2.16%, respectively. Distribution coefficients and separation factors were measured to evaluate the extracting capability of the solvents. The results show that butyl acetate may be considered as a reliable organic solvent for the extraction of phosphoric acid from aqueous solutions.

Ghanadzadeh, H. [Department of Chemistry, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of); Department of Chemical Engineering, University of Guilan, Rasht (Iran, Islamic Republic of); Ghanadzadeh, A. [Department of Chemistry, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of)], E-mail: aggilani@guilan.ac.ir; Bahrpaima, Kh. [Department of Chemistry, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of)

2008-12-15

322

Polyacrylonitrile/manganese acetate composite nanofibers and their catalysis performance on chromium (VI) reduction by oxalic acid  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer We have successfully prepared PAN/Mn(CH{sub 3}COO){sub 2} composite nanofibers. Black-Right-Pointing-Pointer The nanofibers exhibit excellent catalysis performance for Cr(VI) reduction. Black-Right-Pointing-Pointer The nanofibers are effective and environment-friendly materials to remove Cr(VI). - Abstract: Polyacrylonitrile(PAN)/manganese acetate(Mn(CH{sub 3}COO){sub 2}) composite nanofibers have been fabricated by electrospinning, a simple and effective technology. The obtained composite nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FT-IR). The composite nanofibers are amorphous in structure, continuous, even and smooth. At the same time, the reduction performance of Cr(VI) by oxalic acid in the presence of the composite nanofibers is also investigated. The results indicate that the composite nanofibers have exhibited excellent catalysis performance for Cr(VI) reduction from a Cr{sub 2}O{sub 7}{sup 2-}-containing solution by oxalic acid. And the critical parameters, such as the catalyst dosage, oxalic acid content, chromium concentration, the pH value of the reaction solution and light have important impact on the reduction process. Under the simulated solar light irradiation, after only 60 min, 1.2 mM initial Cr(VI) solution was reduced absolutely in the presence of PAN/Mn(CH{sub 3}COO){sub 2} composite nanofibers containing 17.5 wt.% Mn(CH{sub 3}COO){sub 2} by 0.3 mL 0.5 M oxalic acid. In light, the reduction of Cr(VI) by oxalic acid is markedly accelerated.

Zhang, Chengcheng [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China); Li, Xiang, E-mail: xiangli@jlu.edu.cn [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China); Bian, Xiujie; Zheng, Tian [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China); Wang, Ce, E-mail: cwang@jlu.edu.cn [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China)

2012-08-30

323

Polyacrylonitrile/manganese acetate composite nanofibers and their catalysis performance on chromium (VI) reduction by oxalic acid  

International Nuclear Information System (INIS)

Highlights: ? We have successfully prepared PAN/Mn(CH3COO)2 composite nanofibers. ? The nanofibers exhibit excellent catalysis performance for Cr(VI) reduction. ? The nanofibers are effective and environment-friendly materials to remove Cr(VI). - Abstract: Polyacrylonitrile(PAN)/manganese acetate(Mn(CH3COO)2) composite nanofibers have been fabricated by electrospinning, a simple and effective technology. The obtained composite nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FT-IR). The composite nanofibers are amorphous in structure, continuous, even and smooth. At the same time, the reduction performance of Cr(VI) by oxalic acid in the presence of the composite nanofibers is also investigated. The results indicate that the composite nanofibers have exhibited excellent catalysis performance for Cr(VI) reduction from a Cr2O72?-containing solution by oxalic acid. And the critical parameters, such as the catalyst dosage, oxalic acid content, chromium concentration, the pH value of the reaction solution and light have important impact on the reduction process. Under the simulated solar light irradiation, after only 60 min, 1.2 mM initial Cr(VI) solution was reduced absolutely in the presence of PAN/Mn(CH3COO)2 composite nanofibers containing 17.5 wt.% Mn(CH3COO)2 by 0.3 mL 0.5 M oxalic acid. In light, the reduction of Cr(VI) by oxalic acid is markedly accelerated.

2012-08-30

324

High temperature stimulates acetic acid accumulation and enhances the growth inhibition and ethanol production by Saccharomyces cerevisiae under fermenting conditions.  

Science.gov (United States)

Cellular responses of Saccharomyces cerevisiae to high temperatures of up to 42 °C during ethanol fermentation at a high glucose concentration (i.e., 100 g/L) were investigated. Increased temperature correlated with stimulated glucose uptake to produce not only the thermal protectant glycerol but also ethanol and acetic acid. Carbon flux into the tricarboxylic acid (TCA) cycle correlated positively with cultivation temperature. These results indicate that the increased demand for energy (in the form of ATP), most likely caused by multiple stressors, including heat, acetic acid, and ethanol, was matched by both the fermentation and respiration pathways. Notably, acetic acid production was substantially stimulated compared to that of other metabolites during growth at increased temperature. The acetic acid produced in addition to ethanol seemed to subsequently result in adverse effects, leading to increased production of reactive oxygen species. This, in turn, appeared to cause the specific growth rate, and glucose uptake rate reduced leading to a decrease of the specific ethanol production rate far before glucose depletion. These results suggest that adverse effects from heat, acetic acid, ethanol, and oxidative stressors are synergistic, resulting in a decrease of the specific growth rate and ethanol production rate and, hence, are major determinants of cell stability and ethanol fermentation performance of S. cerevisiae at high temperatures. The results are discussed in the context of possible applications. PMID:24706214

Woo, Ji-Min; Yang, Kyung-Mi; Kim, Sae-Um; Blank, Lars M; Park, Jin-Byung

2014-07-01

325

Deuterium isotope effects and solvolysis of tosylates of cis- and trans-2-phenylcyclopentanol in formic acid, acetic acid and ethanol  

International Nuclear Information System (INIS)

The solvolysis of the tosylates of cis and trans 2-phenylcyclopentanol has been studied in formic acid, acetic acid and ethanol by kinetic measurements and secondary isotopes effects. In the case of the cis isomer, hydrogen migration (93 to 97%) from C-2 occurs after rapid ionisation of the tosylate to form an ion-pair which subsequently gives a bridged intermediate in a slow step. With the trans isomer the migration of the hydrogen atom (15 to 47%) and that of the phenyl group (38% in formic acid solution; less than 10% in the two other solvents) would occur in a slow step after ionisation of the tosylate to an intimate ion-pair which dissociates to a loose solvent-separated ion-pair

1979-01-01

326

Transgenically enhanced expression of indole-3-acetic Acid confers hypervirulence to plant pathogens.  

Science.gov (United States)

ABSTRACT Fusarium oxysporum and F. arthrosporioides, pathogenic on Orobanche aegyptiaca, were transformed with two genes of the indole-3-acetamide (IAM) pathway leading to indole-3-acetic acid (IAA) to attempt to enhance virulence. Transgenic F. oxysporum lines containing both the tryptophan-2-monooxyngenase (iaaM) and indole-3-acetamide hydrolase (iaaH) genes produced significantly more IAA than the wild type. IAM accumulated in culture extracts of F. oxysporum containing iaaM alone. F. arthrosporioides containing only iaaM accumulated IAM and an unidentified indole. Some transformants of F. oxysporum expressing only the iaaM gene also produced more IAA than the wild type. Sub-threshold levels (that barely infect Orobanche) of transgenic F. oxysporum expressing both genes and of F. arthrosporioides expressing iaaM were more effective in suppressing the number and size of Orobanche shoots than the wild type on tomato plants grown in soil mixed with Orobanche seed. Stimulating an auxin imbalance enhanced pathogen virulence by affecting the host in a manner similar to low doses of auxin herbicides such as 2,4-dichlorophenoxy acetic acid. PMID:18944254

Cohen, Barry A; Amsellem, Ziva; Maor, Rudy; Sharon, Amir; Gressel, Jonathan

2002-06-01

327

Agreement Between Visual Inspection with Acetic Acid and Papanicolaous Smear as Screening Methods for Cervical Cancer  

International Nuclear Information System (INIS)

Objective: To determine degree of agreement between visual inspection with acetic acid (VIA) and Papanicolaous (Pap) smear as screening methods for cervical cancer. Study Design: A cross-sectional study. Place and Duration of Study: Department of Obstetrics and Gynaecology, Sir Ganga Ram Hospital, Lahore, from July to December 2012. Methodology: Two hundred and fifty women in reproductive age group presenting with various gynaecological complaints were included in the study. A Papanicolaous smear was taken and visual inspection with 5% acetic acid was done. VIA was reported as positive or negative according to acetowhite changes and cytology result was graded as CIN 1, 2, 3 and squamous carcinoma. Those women who showed positive result with either VIA or Pap smear or both were further subjected to colposcopic directed biopsy which was taken as gold standard. Results were computed using Statistical Package for Social Sciences (SPSS) version 16 and statistical test used was kappa. Results: Out of 250 women, VIA was positive in 55 (22%) patients and Pap smear was abnormal in 27 (10.8%). Histological diagnosis of CIN/cancer was made in 36 out of a total 62 patients who underwent biopsy. Conclusion: There was a fair agreement between VIA and Pap smear, with VIA detecting more abnormalities than cytology. In the absence of Pap smear availability, VIA may be a reasonable cervical cancer screening method, especially in low resource settings. (author)

2014-04-01

328

Azithromycin and erythromycin ameliorate the extent of colonic damage induced by acetic acid in rats  

International Nuclear Information System (INIS)

Ulcerative colitis is a common inflammatory bowel disease (IBD) of unknown etiology. Recent studies have revealed the role of some microorganisms in the initiation and perpetuation of IBD. The role of antibiotics in the possible modulation of colon inflammation is still uncertain. In this study, we evaluated the effects of two macrolides, namely azithromycin and erythromycin, at different doses on the extent and severity of ulcerative colitis caused by intracolonic administration of 3% acetic acid in rats. The lesions and the inflammatory response were assessed by histology and measurement of myeloperoxidase (MPO) activity, nitric oxide synthetase (NOS) and tumor necrosis factor alpha (TNF?) in colonic tissues. Inflammation following acetic acid instillation was characterized by oedema, diffuse inflammatory cell infiltration and necrosis. Increase in MPO, NOS and TNF? was detected in the colonic tissues. Administration of either azithromycin or erythromycin at different dosage (10, 20 and 40 mg/kg orally, daily for 5 consecutive days) significantly (P < 0.05) reduced the colonic damage, MPO and NOS activities as well as TNF? level. This reduction was highly significant with azithromycin when given at a dose of 40 mg/kg. It is concluded that azithromycin and erythromycin may have a beneficial therapeutic role in ulcerative colitis

2005-05-15

329

The effect of acetic acid on the CO2 corrosion of grade X70 steel  

International Nuclear Information System (INIS)

The effect of acetic acid (HAc) on the CO2 corrosion of grade X70 steel was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), polarization tests and electrochemical impedance spectroscopy (EIS). In the absence of acetic acid, a fairly dense layer of iron carbonate (FeCO3/siderite) was formed. At 500 ppm HAc, FeCO3 layer became more porous. In addition, anodic/cathodic polarization curves were activated with the more pronounced effect on the cathodic side. By adding 1000 ppm HAc, similar polarization behavior was obtained and FeCO3 layer became yet more porous than previous conditions. At 2000 ppm HAc, FeCO3 layer disappeared completely, while polarization behavior changed and the limiting diffusive current density was observed in the cathodic side. There were two major increases in the corrosion rate at 500 and 2000 ppm HAc. The EIS results reflected similar behavior for the specimens exposed to the solutions with 0-1000 ppm HAc. Under these conditions, a charge transfer controlled behavior due to the FeCO3 layer was observed which was accelerated by increasing HAc concentration. At 2000 ppm HAc, the corrosion behavior changed considerably and the formation/adsorption of corrosion product followed by the dissolution process was observed.

2010-10-01

330

Toward targeted 'oxidation therapy' of cancer: peroxidase-catalysed cytotoxicity of indole-3-acetic acids  

International Nuclear Information System (INIS)

Purpose: The study aimed to identify suitable prodrugs that could be used to test the hypothesis that peroxidase activity in cells, either endogenous or enhanced by immunological targeting, can activate prodrugs to cytotoxins. We hypothesized that prototype prodrugs based on derivatives of indole-3-acetic acid (IAA), when activated by peroxidase enzymes (e.g., from horseradish, HRP) should produce peroxyl radicals, with deleterious biological consequences. Methods and Materials: V79 hamster cells were incubated with IAA or derivatives ± HRP and cytotoxicity assessed by a clonogenic assay. To assess the toxicity of stable oxidation products, prodrugs were also oxidized by HRP without cells, and the products then added to cells. Results: The combination of prodrug and enzyme resulted in cytotoxicity, but neither indole nor enzyme in isolation was toxic under the conditions used. Although lipid peroxidation was stimulated in liposomes by the prodrug/enzyme treatment, it could not be measured in mammalian cells. Adding oxidized prodrugs to cells resulted in cytotoxicity. Conclusions: Although the hypothesis that prodrugs of this type could enhance oxidative stress via lipid peroxidation was not established, the results nonetheless demonstrated oxidatively-activated cytotoxicity via indole acetic acid prodrugs, and suggested these as a new type of substrate for antibody-directed enzyme-prodrug therapy (ADEPT). The hypothesized free-radical fragmentation intermediates were demonstrated, but lipid peroxidation associated with peroxyl radical formation was unlikely to be the major route to cytotoxicity

1998-11-01

331

Rapid identification of acetic acid bacteria using MALDI-TOF mass spectrometry fingerprinting.  

Science.gov (United States)

Acetic acid bacteria (AAB) are widespread microorganisms characterized by their ability to transform alcohols and sugar-alcohols into their corresponding organic acids. The suitability of matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF MS) for the identification of cultured AAB involved in the industrial production of vinegar was evaluated on 64 reference strains from the genera Acetobacter, Gluconacetobacter and Gluconobacter. Analysis of MS spectra obtained from single colonies of these strains confirmed their basic classification based on comparative 16S rRNA gene sequence analysis. MALDI-TOF analyses of isolates from vinegar cross-checked by comparative sequence analysis of 16S rRNA gene fragments allowed AAB to be identified, and it was possible to differentiate them from mixed cultures and non-AAB. The results showed that MALDI-TOF MS analysis was a rapid and reliable method for the clustering and identification of AAB species. PMID:23182036

Andrés-Barrao, Cristina; Benagli, Cinzia; Chappuis, Malou; Ortega Pérez, Ruben; Tonolla, Mauro; Barja, François

2013-03-01

332

PREPARATION AND CHARACTERIZATION OF ACETIC ACID LIGNIN-BASED EPOXY BLENDS  

Directory of Open Access Journals (Sweden)

Full Text Available Lignin-based epoxy resin (LER was prepared from phenolated lignin (PL and epichlorohydrin (ECH in the presence of sodium hydroxide. The eucalyptus acetic acid lignin (AAL was first reacted with phenol in the presence of sulfuric acid to obtain PL. Then, PL was reacted with ECH in aqueous sodium hydroxide to obtain LER. LER was mixed with diglycidyl ether of bisphenol A (E-44 and then cured with triethylenetetramine (TETA. The initial thermal degradation temperature (Td of the cured epoxy blends decreased with the increase in LER content. The residue ratio at 500 °C of the cured epoxy blends (R500, however, increased with the LER content. The maximum adhesive shear strength of the cured epoxy blends was obtained at 20 wt% of LER. The water absorption of epoxy blends increased with increasing the content of LER. SEM photos showed that increasing the content of LER increased inhomogeneity and porosity of epoxy blends.

Fangeng Chen

2012-05-01

333

Allergic Contact Dermatitis Syndrome Due to Tocopherol Acetate, in Addition to Glycyrrhetinic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Natural vitamin E is suggested to have an antioxidant function. However, the synthetic form of vitamin E, DL-tocopherol, which has been widely used in topical ointments, may cause allergic contact dermatitis. Here, we report a case of allergic contact dermatitis with erythema multiforme-like eruption caused by a topical ointment. Patch testing indicated a positive allergic reaction to an anti-inflammatory ointment the patient had been using and its ingredient, DL-alpha-tocopheryl acetate (vitamin E. In addition, a positive reaction to glycyrrhetinic acid was observed. Both vitamin E and glycyrrhetinic acid are useful ingredients of topical applications. However, the possibility that both can cause contact dermatitis, albeit rarely, should be considered.

Masaaki Ito

2012-03-01

334

Photodissociation of organic molecules in star-forming regions II: Acetic acid  

CERN Document Server

Fragments from organic molecule dissociation (such as reactive ions and radicals) can form interstellar complex molecules like amino acids. The goal of this work is to experimentally study photoionization and photodissociation processes of acetic acid (CH$_3$COOH), a glycine (NH$_2$CH$_2$COOH) precursor molecule, by soft X-ray photons. The measurements were taken at the Brazilian Synchrotron Light Laboratory (LNLS), employing soft X-ray photons from a toroidal grating monochromator (TGM) beamline (100 - 310 eV). Mass spectra were obtained using the photoelectron photoion coincidence (PEPICO) method. Kinetic energy distribution and abundances for each ionic fragment have been obtained from the analysis of the corresponding peak shapes in the mass spectra. Absolute photoionization and photodissociation cross sections were also determined. We have found, among the channels leading to ionization, that only 4-6% of CH$_3$COOH survive the strong ionization field. CH$_3$CO$^+$, COOH$^+$ and CH$_3^+$ ions are the mai...

Pilling, S; Boechat-Roberty, H M

2006-01-01

335

SYNTHESIS OF 2-METHYL4QUINOLONE-3-ACETIC ACIDS WITH POTENTIAL ANTIBACTERIAL ACTIVITY  

Directory of Open Access Journals (Sweden)

Full Text Available A number of quinolone-3-acetic acids were synthesized by cyclocondensation of substituted anilines with diethyl acetylsuccinate in the presence of phosphorous pentoxide and followed by base hydrolysis of the resultant esters to form respective acids. All synthesized compounds were found to exhibit antibacterial activities against a range of gram-positive (Bacillus subtilis, Staphylococcus aureus and gram-negative bacteria (Shigella sonnei, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi by broth dilution method. All the compounds exhibited antibacterial activities comparable to fluoroquinolones and in some cases even better activity was found. These findings suggest a great potential of these compounds for screening and use as antibacterial compounds for further studies with a battery of bacteria.

Fauzia Anjum Chattha

2012-01-01

336

An intercomparison of measurement systems for vapor and particulate phase concentrations of formic and acetic acids  

Science.gov (United States)

During June 1986, eight systems for measuring vapor phase and four for measuring particulate phase concentrations of formic acid (HCOOH) and acetic acid (CH3COOH) were intercompared in central Virginia. HCOOH and CH3COOH vapors were sampled by condensate, mist, Chromosorb 103 GC resin, NaOH-coated annular denuders, NaOH-impregnated quartz filters, K2CO3 and NaCO3-impregnated cellulose filters, and Nylasorb membranes. Atmospheric aerosol was collected on Teflon and Nuclepore filters using both hi-vol and lo-vol systems to measure particulate phase concentrations. Performances of the mist chamber and K2CO3-impregnated filter techniques were evaluated using zero air and ambient air spiked with HCOOH(g) and CH3COOH(g), and formaldehyde from permeation sources. The advantages and drawbacks of these methods are reported and discussed.

Keene, William C.; Talbot, Robert W.; Andreae, Meinrat O.; Beecher, Kristene; Berresheim, Harold

1989-01-01

337

Biorefining of wheat straw using an acetic and formic acid based organosolv fractionation process.  

Science.gov (United States)

To assess the potential of acetic and formic acid organosolv fractionation of wheat straw as basis of an integral biorefinery concept, detailed knowledge on yield, composition and purity of the obtained streams is needed. Therefore, the process was performed, all fractions extensively characterized and the mass balance studied. Cellulose pulp yield was 48% of straw dry matter, while it was 21% and 27% for the lignin and hemicellulose-rich fractions. Composition analysis showed that 67% of wheat straw xylan and 96% of lignin were solubilized during the process, resulting in cellulose pulp of 63% purity, containing 93% of wheat straw cellulose. The isolated lignin fraction contained 84% of initial lignin and had a purity of 78%. A good part of wheat straw xylan (58%) ended up in the hemicellulose-rich fraction, half of it as monomeric xylose, together with proteins (44%), minerals (69%) and noticeable amounts of acids used during processing. PMID:24508905

Snelders, Jeroen; Dornez, Emmie; Benjelloun-Mlayah, Bouchra; Huijgen, Wouter J J; de Wild, Paul J; Gosselink, Richard J A; Gerritsma, Jort; Courtin, Christophe M

2014-03-01

338

Fermentative Conversion of Cellulose to Acetic Acid and Cellulolytic Enzyme Production by a Bacterial Mixed Culture Obtained from Sewage Sludge †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A simple procedure that uses a cellulose-enriched culture started from sewage sludge was developed for producing cellulolytic enzymes and converting cellulose to acetic acid rather than CH4 and CO2. In this procedure, the culture which converts cellulose to CH4 and CO2 was mixed with a synthetic medium and cellulose and heated to 80°C for 15 min before incubation. The end products formed were acetic acid, propionic acid, CO2, and traces of ethanol and H2. Supernatants from 6- to 10-day-old c...

Khan, A. W.; Wall, Duncan; Den Berg, L.

1981-01-01

339

Formation of N,N-Dimethylglycine, Acetic Acid, and Butyric Acid from Betaine by Eubacterium limosum  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two bacterial strains that grow anaerobically on betaine were isolated from enrichment cultures and identified as strains of Eubacterium limosum. In a mineral medium supplemented with yeast extract and Casitone, the doubling time of E. limosum strain 11A on betaine was 6 h at 37°C. The molar growth yield amounted to 9 g of dry cell mass per mol. Betaine was fermented in accordance with the following equation: 7 betaine + 2 CO2 ? 7 N,N-dimethylglycine + 1.5 acetate + 1.5 butyrate. E. limosu...

Mu?ller, E.; Fahlbusch, K.; Walther, R.; Gottschalk, G.

1981-01-01

340

Citrate- vs. acetate-based dialysate in bicarbonate haemodialysis: consequences on haemodynamics, coagulation, acid-base status, and electrolytes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background A concentrate for bicarbonate haemodialysis acidified with citrate instead of acetate has been marketed in recent years. The small amount of citrate used (one-fifth of the concentration adopted in regional anticoagulation) protects against intradialyser clotting while minimally affecting the calcium concentration. The aim of this study was to compare the impact of citrate- and acetate-based dialysates on systemic haemodynamics, coagulation, acid-base statu...

2009-01-01

 
 
 
 
341

NMR "1"1B, "1"9F of hydroxofluoroborate solutions in acetic and peracetic acids  

International Nuclear Information System (INIS)

Hydroxofluoroborate solutions in acetic and peracetic acids are studied by the "1"1B, "1"9F NMR method. The reactions of substitutions of acetate- and peracetate ions for nucleophilic hydroxogroups with the formation of the respective complexes are shown to occur in these solutions, with monodentate coordination of BF_3CH_3COO"-- and BF_3CH_3COOO"-- groups being accomplished in this case

1985-08-01

342

Removal of acidic pharmaceuticals within a nitrifying recirculating biofilter.  

Science.gov (United States)

The fate of pharmaceutically active compounds (PhACs) in wastewater treatment systems is an area of increasing concern. Little research has been done to understand this issue in rural or decentralized communities. The objective of this research was to examine the ability of a bench scale nitrifying recirculating biofilter (RBF) to remove four acidic PhACs: gemfibrozil, naproxen, ibuprofen and diclofenac from secondary treated municipal wastewater at concentrations of 20 and 200?g/L. The average removals in this study were between 92 and 99% for ibuprofen, 89 and 99% for naproxen, 62 and 92% for gemfibrozil and 40 and 76% for diclofenac, which is consistent with literature. Ibuprofen and naproxen were largely removed through biological transformation; whereas gemfibrozil and diclofenac showed more variable removal, likely due to both biological transformation and sorption processes. PhAC removal in the RBFs was repeatable between trials, robust and responsive to system upsets, and the presence of PhACs as a single compound versus mixtures had no impact on PhAC removal efficiency. In summary, this study indicates that RBFs as a nitrifying stage of a multi-stage filtration process could be a viable technology for removal of some acidic pharmaceuticals in small onsite wastewater treatment facilities. PMID:24727009

Krkošek, W H; Payne, S J; Gagnon, G A

2014-05-30

343

The Effect of Pre-chilling with Acetic and Lactic Acid on Shelf-life of Broiler Carcasses  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of pre-chilling in acetic and lactic acid solutions on shelf-life of broiler carcass was investigated. Broiler carcasses were subjected to a 10-min pre-chill treatment with acetic acid, lactic acid and combination of them and examined for their sensorial properties, microbiological quality, pH values and ammonia levels. Treating with organic acids decreased initial microbial load of the carcasses, but not changed their colour, odour and appearance. Controls were spoiled on the 4th day of the storage. The shelf-life of carcasses treated with organic acids were 2-4 days longer. Especially, treatments with 0.6 % lactic acid and 1.0 % acetic acid enhanced the shelf-life twice more. Microbial counts (especially pseudomonas, NH3 amount and pH values of carcass were increased parallel to sensorial alterations. The data from the present study suggest that the treatment of broiler carcasses with pre-chill water containing acetic or lactic acid can help to decontaminate and to increase the shelf-life of carcasses without altering the colour and appearance of the skin.

Kamil Bostan

2001-01-01

344

Developmental toxicity of mixtures: the water disinfection by-products dichloro-, dibromo- and bromochloro acetic acid in rat embryo culture  

Science.gov (United States)

The chlorination of drinking water results in production of numerous disinfection by-products (DBPs). One of the important classes of DBPs is the haloacetic acids. We have previously shown that the haloacetic acids (HAs), dichloro (DCA), dibromo (DBA) and bromochloro (BCA) acetic...

345

Production of acetic acid and glycerol from salted and dried whey in a membrane cell recycle bioreactor  

Energy Technology Data Exchange (ETDEWEB)

The use of salted whey (liquid by-product from the dairy industry containing 7.5% NaCl) as a substrate for either acetic acid or glycerol production was investigated using two yeast strains. One was Kluyveromyces fragilis. The other organism (strain L) can utilize whey lactose that was isolated from waste whey (disposal stream). 8% NaCl, 3% Na{sub 2}SO{sub 3} and pH 8.5 at 32{sup o}C were the optimum operating conditions for maximum acetic acid production (25.84 gl{sup -1}) from salted whey using immobilized cells of yeast strain L. Also, strain L have a higher yield of acetic acid (0.497 g acetic acid per gram lactose) as compared with K. fragilis (0.322 g acetic acid per gram lactose). 1% Na{sub 2}SO{sub 3} at pH 7 and whey supplemented with peptone and malt extract were the optimal conditions for maximum batch glycerol production (13.2 gl{sup -1}) from salted whey using immobilized cells of K. fragilis. The extreme values, 18.7 gl{sup -1} for glycerol concentration and 39.78 for the percent yield of glycerol (based on sugar concentration) in a membrane cell recycle bioreactor were higher than those obtained for the immobilized cell batch reactors (13.2 gl{sup -1} and 28, respectively). (Author)

Mostafa, N.A. [Minia Univ. (Egypt). Dept. of Chemical Engineering

2001-07-01

346

PHOTOLYSIS RATES OF (2,4,5-TRICHLOROPHENOXY)ACETIC ACID AND 4-AMINO-3,5,6-TRICHLOROPICOLINIC ACID IN NATURAL WATERS  

Science.gov (United States)

Photoreactions of (2,45-trichlorophenoxy) acetic acid (2,4,5-T) and 4-amino-3,5,6-trichloropicolinic acid (picloram) were studied in distilled water, natural water samples, fulvic acid solutions, and solutions containing iron (III) and/or hydrogen peroxide to determine the effect...

347

Biomonitoring of 2-(2-alkoxyethoxy)ethanols by analysing urinary 2-(2-alkoxyethoxy)acetic acids.  

Science.gov (United States)

2-Methoxyacetic and 2-ethoxyacetic acids are well known toxic metabolites of 2-alkoxyethanols. The use of 2-alkoxyethanols is now restricted, and the regulations have forced manufacturers to find substitutive solvents, 2-(2-alkoxyethoxy)ethanols. 2-(2-Alkoxyethoxy)ethanols resemble 2-alkoxyethanols, and their most hazardous similarity is their ability to metabolize to the 2-(2-alkoxyethoxy)acetic acids. In the present study, floor lacquerers' (n = 22) inhalation and total exposure to 2-(2-alkoxy)ethoxyethanols was measured. The measurements of inhalation exposure were done with charcoal tubes, and total exposure was biomonitored by urinalysis of 2-(2-alkoxyethoxy)acetic acids. The 8h inhalation exposures of floor lacquerers to 2-(2-methoxyethoxy)ethanol (DEGME), 2-(2-ethoxyethoxy)ethanol (DEGEE) and 2-(2-butoxyethoxy)ethanol (DEGBE) were in average 0.23 +/- 0.07 ppm (average+/-S.D., n = 3), 0.08 +/- 0.07 ppm (n = 16), and 0.05 +/- 0.03 ppm (n = 16), respectively. The excretions of 2-(2-methoxyethoxy)acetic acid (MEAA), 2-(2-ethoxyethoxy)acetic acid (EEAA) and 2-(2-butoxyethoxy)acetic acid (BEAA) were in average 4.9 +/- 4.3 mmol/mol creatinine, 9.3 +/- 8.0 mmol/mol creatinine and 9.2 +/- 7.4 mmol/mol creatinine, respectively. A linear relationship was found between the urinary 2-(2-alkoxyethoxy)acetic acid concentrations and the preceding 8-h occupational exposure to 2-(2-alkoxyethoxy)ethanol. PMID:15705492

Laitinen, J; Pulkkinen, J

2005-03-28

348

Studies on the complexes of uranium(IV), thorium(IV) and lanthanum(III) acetates with p-aminobenzoic acid, m-aminobenzoic acid, benzilic acid and phthalic acid  

International Nuclear Information System (INIS)

Complexes of acetates of U(IV), Th(IV) and La(III) with the ligands p-aminobenzoic acid, m-aminobenzoic acid, benzilic acid and phthalic acid have been prepared. Colour and chemical analytical data are recorded. They are characterised on the basis of IR and reflectance spectra and magnetic susceptibility data. (M.G.B.)

1979-12-01

349

Sol-gel process for preparing YBa2Cu4O8 precursors from Y, Ba, and Cu acidic acetates/ammonia/ascorbic acid systems  

International Nuclear Information System (INIS)

Sols were prepared by addition of ammonia to acidic acetate solutions of Y3+, Ba2+, and Cu2+. Ascorbic acid was added to a part of the sol. The resultant sols were gelled to a shard, a film, or microspheres by evaporation at 60 C or by extraction of water from drops of emulsion suspended in 2-ethylhexanol-1. Addition of ethanol to the sols facilitated the formation of gel films, fabricated by a dipping technique, on glass or silver substrates. At 100 C, gels that were formed in the presence of ascorbic acid were perfectly amorphous, in contrast to the crystalline acetate gels. Conversion of the amorphous ascorbate gels to final products was easier than for the acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings

1995-09-18

350

Effect of humic acid on the underpotential deposition-stripping voltammetry of copper in acetic acid soil extract solutions at mercaptoacetic acid-modified gold electrodes  

International Nuclear Information System (INIS)

Electrochemical measurements were undertaken for the investigation of the underpotential deposition-stripping process of copper at bare and modified gold electrodes in 0.11 M acetic acid, the first fraction of the European Union's Bureau Communautaire de References (BCR) sequential extraction procedure for fractionating metals within soils and sediments. Gold electrodes modified with mercaptoacetic acid showed higher sensitivity for the detection of copper than bare gold electrodes, both in the absence and in the presence of humic acid in acetic acid solutions, using the underpotential deposition-stripping voltammetry (UPD-SV) method. In the presence of 50 mg l-1 of humic acid, the mercaptoacetic acid modified electrode proved to be 1.5 times more sensitive than the bare gold electrode. The mercaptoacetic acid monolayer formed on the gold surface provided efficient protection against the adsorption of humic acid onto the gold electrode surface. Variation of the humic acid concentration in the solution showed little effect on the copper stripping signal at the modified electrode. UPD-SV at the modified electrode was applied to the analysis of soil extract samples. Linear correlation of the electrochemical results with atomic spectroscopic results yielded the straight-line equation y (?g l-1) = 1.10x - 44 (ppb) (R=0.992, n=6), indicating good agreement between the two methods

2004-05-24

351

Changes in Growth, Auxin- and Ribonucleic Acid Metabolism in Wheat Coleoptile Sections Following Pulse Treatment with Indole-3-Acetic Acid  

DEFF Research Database (Denmark)

Growth reactions of wbeat coleoptile sections following a brief pretreament in indole-3-acetic acid (LAA) were studied. The growth versus concentration curves 24 hours after the treatment showed a minimum value surrounded by bigber values. The minimum was never at concentrations lower than 10-5M lAA but it could be found at higher concentrations after short pretreatment periods. The growth versus time curves reveated that the hormone treatment cansed the growth rate initially to increase but later on to decrease. The decrease was followed by a second increase for some treatments. Analysis of IAA content after the pretreatment showed that the attered growth patterns could be ascribed to declining auxin content with time, but not to thc actual concentration in the sections. The results indicate that the metabolic activation brought about by IAA leads to its own disappearance. Such a phenomenon was mirroretl in effects of IAA on hte net synthesis of ribonucleic acid.

Truelsen, T.A.; Galston, A.W.

1966-01-01

352

Protective Effect of Alpha-lipoic Acid Against Lead Acetate-Induced Oxidative Stress in the Bone Marrow of Rats  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was designed to investigate the effects of alpha Lipoic Acid (LA against lead acetate induced changes in free radical scavenging enzymes and lipid hydroperoxides in bone marrow of rats. Rats were exposed to lead acetate in their drinking water (500 ppm for 14 days and alpha lipoic acid was given concurrently (25, 50 and 100 mg kg-1. Blood lead levels, lipid hydroperoxides, protein carbonyl contents and oxidative marker enzymes were estimated. Lead acetate in drinking water had elicited a significant (p-1 b.wt. LA. The potency of alpha lipoic acid on the reversal of lead induced changes in oxidative biomarkers in bone marrow confirms the importance of lead induced oxidative stress in bone and suggests a therapeutic approach.

Srikumar Chakravarthi

2011-01-01

353

Metal-organic coordination architectures of azole heterocycle ligands bearing acetic acid groups: Synthesis, structure and magnetic properties  

Science.gov (United States)

Four new coordination complexes with azole heterocycle ligands bearing acetic acid groups, [Co( L1) 2] n ( 1) , [Cu L1N 3] n ( 2), [Cu( L2) 2·0.5C 2H 5OH·H 2O] n ( 3) and [Co( L2) 2] n ( 4) (here, H L1=1H-imidazole-1-yl-acetic acid, H L2=1H-benzimidazole-1-yl-acetic acid) have been synthesized and structurally characterized. Single-crystal structure analysis shows that 3 and 4 are 2D complexes with 4 4-sql topologies, while another 2D complex 1 has a (4 3) 2(4 6)-kgd topology. And 2 is a 3D complex composed dinuclear ?1,1-bridging azido Cu II entities with distorted rutile topology. The magnetic properties of 1 and 2 have been studied.

Hu, Bo-Wen; Zhao, Jiong-Peng; Yang, Qian; Hu, Tong-Liang; Du, Wen-Ping; Bu, Xian-He

2009-10-01

354

Engineering efficient xylose metabolism into an acetic acid-tolerant Zymomonas mobilis strain by introducing adaptation-induced mutations.  

Science.gov (United States)

The impact of the two adaptation-induced mutations in an improved xylose-fermenting Zymomonas mobilis strain was investigated. The chromosomal mutation at the xylose reductase gene was critical to xylose metabolism by reducing xylitol formation. Together with the plasmid-borne mutation impacting xylose isomerase activity, these two mutations accounted for 80 % of the improvement achieved by adaptation. To generate a strain fermenting xylose in the presence of high acetic acid concentrations, we transferred the two mutations to an acetic acid-tolerant strain. The resulting strain fermented glucose + xylose (each at 5 % w/v) with 1 % (w/v) acetic acid at pH 5.8 to completion with an ethanol yield of 93.4 %, outperforming other reported strains. This work demonstrated the power of applying molecular understanding in strain improvement. PMID:22669340

Agrawal, Manoj; Wang, Yun; Chen, Rachel Ruizhen

2012-10-01

355

Effect of acetic acid on ZnO:In transparent conductive oxide prepared by ultrasonic spray pyrolysis  

International Nuclear Information System (INIS)

Undoped and indium doped zinc oxide (ZnO) transparent conductive oxide were prepared by a low-cost Ultrasonic Spray Pyrolysis. The influence of acetic acid on properties of the ZnO thin films was investigated. The complex formed by [CH3COO?] and [Zn2+] in precursor solution was better for the growth of ZnO film. The acetic acid added in precursor solution can supply [CH3COO?] for both [Zn2+] and [In3+] to form complexes. That made the [Zn2+] and [In3+] have similar statement, which can promote the indium doping in the ZnO films. The surface morphology, structural and electrical properties of the ZnO thin films were influenced by the acetic acid adding. The total transmittance of the ZnO thin films is above 80% in the wide wavelength region from 400 nm to 2000 nm.

2011-12-01

356

Removal of coagulant aluminum from water treatment residuals by acid.  

Science.gov (United States)

Sediment sludge during coagulation and sedimentation in drinking water treatment is called "water treatment residuals (WTR)". Polyaluminum chloride (PAC) is mainly used as a coagulant in Japan. The recycling of WTR has been desired; one method for its reuse is as plowed soil. However, WTR reuse in this way is inhibited by the aluminum from the added PAC, because of its high adsorption capacity for phosphate and other fertilizer components. The removal of such aluminum from WTR would therefore be advantageous for its reuse as plowed soil; this research clarified the effect of acid washing on aluminum removal from WTR and on plant growth in the treated soil. The percentage of aluminum removal from raw WTR by sulphuric acid solution was around 90% at pH 3, the percentage decreasing to 40% in the case of a sun-dried sample. The maximum phosphate adsorption capacity was decreased and the available phosphorus was increased by acid washing, with 90% of aluminum removal. The enhancement of Japanese mustard spinach growth and the increased in plant uptake of phosphates following acid washing were observed. PMID:24835954

Okuda, Tetsuji; Nishijima, Wataru; Sugimoto, Mayo; Saka, Naoyuki; Nakai, Satoshi; Tanabe, Kazuyasu; Ito, Junki; Takenaka, Kenji; Okada, Mitsumasa

2014-09-01

357

Synthesis Of Some New Benzimidazole Acetic Acid Derivatives And Evaluation For Their Antimicrobial And Antitubercular Activities  

Directory of Open Access Journals (Sweden)

Full Text Available  Substituted benzimidazole  have received considerable attention during last few decades as they are endowed with variety of biological activities and have wide range of therapeutic properties. A literature survey indicates that benzimidazole derivatives possess different biological activities such as anti-microbial activity, anti-ulcer ,antiparasitic, antiprotozoal , antiviral and antitubercular.         Physical properties shown that, Benzimidazoles have high melting points, Benzimidazoles are usually soluble in polar solvents and sparingly soluble in non polar solvent,Benzimidazoles are weakly basic, being some what less basic than imidazole, Benzimidazoles are also sufficiently acidic to be generally soluble in aqueous alkali . The acidic properties of benzimidazoles, like those of imidazole, seem to be due to stabilization of the ion by resonance. The pKa value of benzimidazoles (pKa=5.30A new series of benzimidazoles acetic acid derivatives were synthesized by reacting 2(2-substituted phenyl ethenyl 1H benzimidazole with chloroacetic acid under reflux. The structures of these compounds were established by means of IR, 1H-NMR, 13C-NMR and elemental analysis. All compounds were evaluated for antibacterial, antifungal and antitubercular activities.       Most of the compounds have shown significant antibacterial, antifungal and antitubercular activity when compared with the standard drug Stryptomycin.

Sachin Kale

2013-05-01

358

Spectrophotometric determination of beryllium with sulfochlorophenol S in organo-aqueous acetic-acid media  

International Nuclear Information System (INIS)

The possibility has been shown of photometric determination of beryllium with sulphochlorophenol S using an acetic acid-propanol mixture (1:1), containing 0.5-1.5 vol% of water, as the reaction medium. Under such conditions, the reaction between beryllium and sulphochlorophenol S is sensitive and selective with respect to some easily hydrolized elements (Sn, Bi, Sb, Hg) as well as to Ga, In, Tl, Zn in the presence of HCl. The following excess amounts do not interfere with the determination of 0.45 ?g Be: Hg-1.2x10"4, Sb-6.2x10"3, In-2.5x10"3, Tl-2.0x10"3, Zn-1.4x10"3, Ga-1.2x10"3. The reaction between beryllium and sulphochlorophenol S is selective with respect to a number of complexing agents. Beryllium can be determined in the presence of 150000-200000 times its weight amounts of tartaric, citric and boric acids, 5000-sulphosalycilic acid, 6000-oxalic acid, 6000-dimethyl glyoxime, 150-8-hydroxyquinoline

1981-01-01

359

Native lignin structure of Miscanthus x giganteus and its changes during acetic and formic acid fractionation.  

Science.gov (United States)

Milled wood lignin (MWL) and acetic and formic acid lignin (AL and FL) from Miscanthus x giganteus bark were produced, respectively, before and after organosolv fractionations under optimal conditions, in terms of organic and hydrochloric acid concentrations, liquid/wood ratio, and reaction time. In order to study the M. x giganteus native lignin structure and its modifications during the fractionation process, the lignins were studied by two-dimensional heteronuclear single quantum coherence (2D-(HSQC)), (13)C- and (31)P nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR), size-exclusion chromatography (SEC) both before and after thioacidolysis, and elemental analysis. In addition, chemical composition analysis was performed on ash, Klason lignin, and carbohydrate content. The analyses demonstrated that M. x giganteus native lignin (MWL) is highly acylated at the C(gamma) of the lignin side chain (46%), possibly with p-coumarate and/or acetate groups. This is newsworthy since several earlier studies showed that acylation at the gamma-carbon commonly occurs in C(3) and CAM grasses, whereas M. x giganteus is a C(4) grass. Furthermore, M. x giganteus showed a low S/G ratio (0.7) and a predominance of beta-O-4' linkages (up to 93% of all linkages). AL and FL lose part of these linkages during organosolv fractionation (up to 21 and 32%, respectively). The p-coumarate groups resist fractionation processes and are still present in high quantities in AL and FL. During the fractionation process, lignin is acetylated (acetic acid process) and condensed, with the G units condensing more than S units. M. x giganteus MWL contains a high content of carbohydrates (22.8%), suggesting that it is a lignin-carbohydrate complex (LCC). AL and FL showed low carbohydrate contents because of the breaking down of the LCC structures. AL and FL have high molecular weights and low polydispersities, and are high in phenolic content, qualities that make these suitable for different applications. These results suggest that refinement of M. x giganteus via organosolv processes could potentially turn this grass into a valuable source of both fiber and lignin. PMID:19552425

Villaverde, Juan José; Li, Jiebing; Ek, Monica; Ligero, Pablo; de Vega, Alberto

2009-07-22

360

Reaction of 13N produced by recoil deuterons in pile-irradiated acetic acid-d4 and malonic acid-d4  

International Nuclear Information System (INIS)

The reaction of 13N to form 13N-labelled compounds was studied in acetic acid-d4 as a function of the halogenoacetic acid concentration and in malonic acid-d4 as a function of the intermolecular distance of target malonic acid-d4 at 195 and 295+-6 K. The yield of (13N)glycine formed in acetic acid-d4 were markedly enhanced by iodoacetic acid and slightly by chloroacetic acid. In malonic acid-d4, the yield of 13NH3 was directly proportional to the cubic root of the molar ratio, while the yields of H13N3, (13N)aminomalonic acid and HC13N were inversely proportional to the cubic root of the molar ratio. The mechanism of the formation of the 13N compounds are discussed. (author)

1987-06-30

 
 
 
 
361

A contribution to the distinction of biogenic vinegar and vinegar made from synthetic acetic acid by determining the specific 14C-radioactivity  

International Nuclear Information System (INIS)

The method of Simon et al. for the separation of the acetic acid from vinegar prior to the determination of the specific 14C-radioactivity has been modified. The precipitation as calcium acetate and the preparation of free acetic acid by addition of diphosphoric acid has been replaced by an extraction procedure with diisopropylether which is faster and cheaper. On the Austrian market glacial acetic acid (Merck, p.A.) having the natural specific 14C-radioactivity was found. The natural specific 14C-radioactivity is therefore necessary but not sufficient to prove the biogenic origin of vinegar. (orig.)

1977-01-01

362

Translocation of radiolabeled indole-3-acetic acid and indole-3-acetyl-myo-inositol from kernel to shoot of Zea mays L  

Science.gov (United States)

Either 5-[3H]indole-3-acetic acid (IAA) or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm of kernels of dark-grown Zea mays seedlings. The distribution of total radioactivity, radiolabeled indole-3-acetic acid, and radiolabeled ester conjugated indole-3-acetic acid, in the shoots was then determined. Differences were found in the distribution and chemical form of the radiolabeled indole-3-acetic acid in the shoot depending upon whether 5-[3H]indole-3-acetic acid or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm. We demonstrated that indole-3-acetyl-myo-inositol applied to the endosperm provides both free and ester conjugated indole-3-acetic acid to the mesocotyl and coleoptile. Free indole-3-acetic acid applied to the endosperm supplies some of the indole-3-acetic acid in the mesocotyl but essentially no indole-3-acetic acid to the coleoptile or primary leaves. It is concluded that free IAA from the endosperm is not a source of IAA for the coleoptile. Neither radioactive indole-3-acetyl-myo-inositol nor IAA accumulates in the tip of the coleoptile or the mesocotyl node and thus these studies do not explain how the coleoptile tip controls the amount of IAA in the shoot.

Chisnell, J. R.; Bandurski, R. S.

1988-01-01

363

Bio-available amino acids extraction from soil by demineralized water and 0.5 M ammonium acetate.  

Science.gov (United States)

The extraction and comparison of soil bio-available amino acids using either demineralised water (DEMI H(2)O) or 0.5 M ammonium acetate (0.5 M AAc) solution is reported. Results show that the extraction by 0.5 M AAc is a better method to assess the concentration of bio-available amino acids in soil than DEMI H(2)O due to higher extraction efficiency and better amino acid protection against microbial degradation during processing. PMID:15838591

Formánek, P; Klejdus, B; Vranová, V

2005-06-01

364

Removal of iodine species with concentrated nitric acid, (3)  

International Nuclear Information System (INIS)

In the reprocessing of FBR spent fuel, the removal of radioactive iodine by the Iodox process (the absorption by highly concentrated nitric acid) has been studied, but also the steps to concentrate and solidify the iodine for storage must be examined. The behavior of iodine in these steps must be made clear for the evaluation of iodine removal. The results of the fundamental experiments in this connection using 131I as a tracer are described. The effects of parameters on iodine removal, i.e. nitric acid concentration and iodine concentration, were examined, and a method to minimize the quantity of released iodine was studied. (1) Higher concentration of nitric acid is better for iodine concentration. (2) It is desirable that the quantity of NOx in nitric acid is as low as possible. (3) It is not necessary to consider the release of iodine during solidification at the temperature lower than 190 deg C. Since (1) and (2) above contradict, some new special treatment of nitric acid has to be developed. When the solution is solidified at temperature higher than 190 deg C, the thermal decomposition of I2O5 must be considered. (J.P.N.)

1979-02-01

365

Anticoccidial effects of acetic acid on performance and pathogenic parameters in broiler chickens challenged with Eimeria tenella  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objective of the present study was to evaluate the anticoccidial effect of the different concentrations of the acetic acid in the broiler chickens in comparison with the amprolium anticoccidial. A total of 198 chicks were placed 11 per pen with three pens per treatment. The different concentrations (1%, 2% and 3%) of acetic acid and amproilum (at the dose rate of 125ppm) were given to the experimental groups in drinking water from 10-19th days of age. One group was kept as infected non me...

2011-01-01

366

Soni-removal of nucleic acids from inclusion bodies.  

Science.gov (United States)

Inclusion bodies (IBs) are commonly formed in Escherichiacoli due to over expression of recombinant proteins in non-native state. Isolation, denaturation and refolding of these IBs is generally performed to obtain functional protein. However, during this process IBs tend to form non-specific interactions with sheared nucleic acids from the genome, thus getting carried over into downstream processes. This may hinder the refolding of IBs into their native state. To circumvent this, we demonstrate a methodology termed soni-removal which involves disruption of nucleic acid-inclusion body interaction using sonication; followed by solvent based separation. As opposed to conventional techniques that use enzymes and column-based separations, soni-removal is a cost effective alternative for complete elimination of buried and/or strongly bound short nucleic acid contaminants from IBs. PMID:24747565

Neerathilingam, Muniasamy; Mysore, Sumukh; Gandham, Sai Hari A

2014-05-23

367

Acetic Acid Bacteria Genomes Reveal Functional Traits for Adaptation to Life in Insect Guts  

Science.gov (United States)

Acetic acid bacteria (AAB) live in sugar rich environments, including food matrices, plant tissues, and the gut of sugar-feeding insects. By comparing the newly sequenced genomes of Asaia platycodi and Saccharibacter sp., symbionts of Anopheles stephensi and Apis mellifera, respectively, with those of 14 other AAB, we provide a genomic view of the evolutionary pattern of this bacterial group and clues on traits that explain the success of AAB as insect symbionts. A specific pre-adaptive trait, cytochrome bo3 ubiquinol oxidase, appears ancestral in AAB and shows a phylogeny that is congruent with that of the genomes. The functional properties of this terminal oxidase might have allowed AAB to adapt to the diverse oxygen levels of arthropod guts.

Chouaia, Bessem; Gaiarsa, Stefano; Crotti, Elena; Comandatore, Francesco; Degli Esposti, Mauro; Ricci, Irene; Alma, Alberto; Favia, Guido; Bandi, Claudio; Daffonchio, Daniele

2014-01-01

368

A new polymorph of 2-(2H-benzotriazol-2-yl)acetic acid.  

Science.gov (United States)

A new polymorph of 2-(benzotriazol-2-yl)acetic acid, C(8)H(7)N(3)O(2), crystallizes in the space group C2/c (Z = 8). The non-planar mol-ecule has a synplanar conformation of the carb-oxy group. The crystal structure features helices parallel to the b axis sustained by O-H?N hydrogen bonding which are similar to those in the known polymorph [Giordano & Zagari (1978 ?). J. Chem. Soc. Perkin Trans. 2, pp. 312-315]. However, in the title structure, columns are formed by ?-? stacking inter-actions between benzotriazole fragments of centrosymmetrically related adjacent mol-ecules [centroid-centroid distances = 3.593?(10) and 3.381?(10)?Å] whereas ?-? stacking inter-actions are not observed in the other polymorph. In the crystal of the title compound, C-H?O inter-actions are also observed. PMID:23125639

Alieva, Guloy; Ashurov, Jamshid; Mukhamedov, Nasir; Parpiev, Nusrat

2012-10-01

369

[Effect of detergents on the hydroxylation of indolyl-3-acetic acid by an Aspergillus niger culture].  

Science.gov (United States)

A possibility to increase the hydroxylating activity of Aspergillus niger IBFM F-212 under the action of detergents was studied during transformation of indolyl-3-acetic acid (IAA). The following non-ionogenic surface-active compounds were mainly used: Tweens, Spans, polyethyleneglycol (PEG-400). The effect of the detergents was studied at the stages of growth, transformation and preincubation. At the stage of growth, the best effect was produced by Tween-80. At the stages of transformation and preincubation, the hydroxylating activity increased 1.5 times under the action of a number of Spans and PEG-400. No total positive effect of the detergents on the enzyme activity was found at the stages of growth and transformation. The results suggest that the cellular permeability changes under the action of detergents and the hydroxylating activity of the culture increases as the result. PMID:7412617

Baklashova, T G; Koshcheenko, K A

1980-01-01

370

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

Science.gov (United States)

Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263+/-0.02 g cellulose L-1 for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

Aydin, Y. Andelib; Aksoy, Nuran Deveci

2010-06-01

371

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

International Nuclear Information System (INIS)

Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263±0.02 g cellulose L-1 for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

2010-06-17

372

Exponential decay activities of radiocesium In mushrooms by the help of acetic acid  

International Nuclear Information System (INIS)

Gross activity of radiocesium in food from environmental ecosystems is decreasing slower than it was supposed and therefore it is subject for public repeatedly. Belong there mushrooms, game and wood fruits. Interest in this problems is and substantial improvement tighten up admissible levels of radioactive contamination of food (137Cs and 134Cs) for irradiation after Chernobyl in public notice for Czech republic is 600 Bq/kg. It is in unity with European Union. We can search possibilities to decrease content of radiocesium in food. Mainly mushrooms cumulate considerable quantity of radiocesium. Were examined samples Boletus badius of three other condition. Samples come from two other localities. Activity of radiocesium was detected by gamma-spectrometry (f.Canberra). For decrease content of radiocesium was using elution in 2% solution of acetate acid. Curve of graphic analysis have exponential nature. (authors)

2004-06-01

373

Study on the IAA (Indole acetic acid) Productivity of Soil Yeast Strain Isolats  

International Nuclear Information System (INIS)

Twelve isolated soil yeast were tested in IAA production in peptone yeast glucose broth (PYG). All strains were screened for the Indole Acetic Acid (IAA) producing activity in PYG broth supplemented with or without L-Tryptophan (L-TRP) as precusor. IAA production was assayed calorimetrically using Salkowski's reagent. The concentration of IAA produced by yeast strains was measured by spectrophotometric method at 530nm. Y6 strain was the highest IAA producer (79ppm) at 9 days incubation period without tryptophan. Y3, Y10 and Y12 strains that were incubated without L-TRP also had the higher ability in the production of IAA than other yeast isolates. The selected yeasts having high IAA production activity were characterized by morphological study and biochemical tests including sugar assimilation and fermentation tests.

2011-12-01

374

Photoinduced excited state proton rearrangement of 6-hydroxyquinoline along a hydrogen-bonded acetic acid wire  

Science.gov (United States)

6-Hydroxyquinoline (6-HQ) in benzene emits normal fluorescence around 357 nm. In the presence of acetic acid (HOAc), it exhibits two more bands at ˜419 nm and a large Stokes shifted one at ˜583 nm with decreased intensity of the normal fluorescence. It appears to form (1:1) and (1:2) complexes-(1:2) 6-HQ/HOAc undergoes an excited state proton rearrangement ( via HOAc wire) resulting in keto tautomer (emitting at ˜583 nm). This appears to be in line with recent findings where ammonia wires facilitate proton/hydrogen translocation (Science, 302, 1736, 2003). However, (1:1) 6-HQ/HOAc exhibits intermediate emission (˜419 nm) presumably due to ESIPT.

Mehata, Mohan Singh

2007-03-01

375

Large-scale gaseous acetic acid treatment to disinfect alfalfa seeds inoculated with Escherichia coli.  

Science.gov (United States)

Most outbreaks of foodborne illness related to sprout consumption are ascribed to bacterial contamination of its seeds, and they need disinfection before sprouting. Recently, gaseous acetic acid (GAA) treatment received great attention as a method for seed disinfection. In this study, the effect of GAA treatment on alfalfa seed disinfection was evaluated in a large-scale device to simulate practical applications. Alfalfa seeds (3?kg) inoculated with Escherichia coli were treated with 8.7% (vol/vol) GAA at 55°C for 1-3?h. The population of E. coli was significantly reduced (palfalfa seeds was not affected by the treatments under all the conditions. The results indicated that the GAA treatment has a potential for practical application to reduce the risk of foodborne illness caused by consumption of sprouts. PMID:24400985

Nei, Daisuke; Enomoto, Katsuyoshi; Yamamoto, Kazutaka

2014-04-01

376

(Liquid + liquid) equilibria of (water + butyric acid + cyclohexyl acetate) ternary system  

International Nuclear Information System (INIS)

(Liquid + liquid) equilibrium (LLE) data for the ternary system (water + butyric acid + cyclohexyl acetate) have been determined experimentally at T (298.15, 308.15 and 318.15) K. Complete phase diagrams were obtained by determining solubility and the tie-line data. Tie-line compositions were correlated by the Othmer-Tobias method. The UNIFAC method was used to predict the phase equilibrium in the system using the interaction parameters determined from experimental data between CH, CH2, CH3, COOH, CH3COO and H2O groups. It is found that UNIFAC group interaction parameters used for LLE could not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region

2005-02-01

377

Highly dispersed supported ruthenium oxide as an aerobic catalyst for acetic acid synthesis  

DEFF Research Database (Denmark)

The increasing need for shifting to renewable feedstocks in the chemical industry has driven research toward using green aerobic, selective oxidation reactions to produce bulk chemicals. Here, we report the use of a ruthenium mixed oxide/hydroxide (RuOx) on different support materials for the selective aerobic oxidation of ethanol to acetic acid. The RuOx was deposited onto different oxide supports using a new gas-phase reaction, which in all cases resulted in homogeneous nanoparticulate films. The RuOx particle size ranged from 0.3 to 1.5nm. The catalytic activity was evaluated on TiO2, Mg6Al2(CO3)(OH)16·4(H2O), MgAl2O4, Na2Ti6O13 nanotubes, ZnO, γ-Al2O3, WO3, CeO2, and Ce0.5Zr0.5O2 supports. The CeO2 supported RuOx had the highest activity, and selectivity toward acetic acid, of all the materials when normalized with respect to Ru-loading. This high activity was independent of the surface area of the support and the loading of RuOx under the tested conditions. This was attributed to the highly uniform size of the RuOx deposits, demonstrating that the deposition is suitable for producing small nanoparticles at high loadings. To elucidate the reason for the promotional effect of CeO2, Ce0.5Zr0.5O2 was investigated as a high oxygen storage capacity support, however, this did not result in higher catalytic activity. The high activity of CeO2 supports compared to the low activity ZnO appear correlated to the presence of high valence Ru(VI) species analogous to that observed in literature.

Laursen, Anders Bo; Gorbanev, Yury

2012-01-01

378

Role of Visual Inspection of Cervix with Acetic Acid (VIA in Detecting Precancerous Lesions of Cervix  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Carcinoma of cervix is the most common malignancy in female and a major public health problem worldwide. It is the leading cause of death from cancer among women in low resource settings. In Bangladesh, mortality rate is high as most of the cases with cervical cancer are diagnosed in advanced stage. World Health Organization considers cervical cancer as a preventable disease as it can be identified in preinvasive stage. Considerable efforts have been given in detection and treatment of the condition all over the world. A number of cervical cancer screening tests are available. Among them, visual inspection of cervix with acetic acid is rational and can be competently performed by physicians with proper training. Objective: To find out the feasibility of the visual inspection of cervix with acetic acid for the detection of the precancerous lesions of the cervix in our country. Materials and Methods: This cross sectional, analytical study was carried out among the patients attending the outpatient department of Bangabandhu Sheikh Mujib Medical University (BSMMU who were VIA positive and sent for colposcopy in the colposcopy clinic in the department of Obstetrics and Gynecology in BSMMU from June to December 2004. Two hundred samples were considered for this study. Results: Out of 200 cases, colposcopically 85% had CIN and invasive lesions, 4% had inflammatory lesions while 11% had normal findings. Colposcopy directed punch biopsy revealed positive lesions in 81%, 4% had inflammatory lesions while 15% had normal findings. Conclusion: The study concluded that VIA and colposcopy are the important methods in the evaluation of cervical premalignancy. VIA may be an important tool for screening of cervical cancer in low resource settings as it is simple, easy to perform and cost-effective. After screening, VIA positive cases must be referred for colposcopic evaluation. We can screen cervical cancer by VIA all over the country and thus reduce morbidity and mortality rate.

Kamrun Nessa

2014-01-01

379

Pickled egg production: effect of brine acetic Acid concentration and packing conditions on acidification rate.  

Science.gov (United States)

U.S. federal regulations require that acidified foods must reach a pH of 4.6 or lower within 24 h of packaging or be kept refrigerated until then. Processes and formulations should be designed to satisfy this requirement, unless proper studies demonstrate the safety of other conditions. Our objective was to determine the effect of brine acetic acid concentration and packing conditions on the acidification rate of hard-boiled eggs. Eggs were acidified (60/40 egg-to-brine ratio) at various conditions of brine temperature, heat treatment to filled jars, and postpacking temperature: (i) 25°C/none/25°C (cold fill), (ii) 25°C/none/2°C (cold fill/refrigerated), (iii) 85°C/none/25°C (hot fill), and (iv) 25°C/100°C for 16 min/25°C (water bath). Three brine concentrations were evaluated (7.5, 4.9, and 2.5% acetic acid) and egg pH values (whole, yolk, four points within egg) were measured from 4 to 144 h, with eggs equilibrating at pH 3.8, 4.0, and 4.3, respectively. Experiments were conducted in triplicate, and effects were considered significant when P < 0.05. Multiple linear regression analysis was conducted to evaluate the effect on pH values at the center of the yolk. Regression analysis showed that brine concentration of 2.5% decreased the acidification rate, while packing conditions of the hot fill trial increased it. Inverse prediction was used to determine the time for the center of the yolk and the total yolk to reach a pH value of 4.6. These results demonstrate the importance of conducting acidification studies with proper pH measurements to determine safe conditions to manufacture commercially stable pickled eggs. PMID:24780334

Acosta, Oscar; Gao, Xiaofan; Sullivan, Elizabeth K; Padilla-Zakour, Olga I

2014-05-01

380

Removal of iodine species with concentrated nitric acid, (7)  

International Nuclear Information System (INIS)

For the Iodox process, which is atrractive for the iodine removal from off-gas stream in nuclear fuel reprocessing, a new iodine treatment process has been examined by laboratory-scale experiment. The process includes the step of stripping iodine from solution by the nitrogen oxide produced from nitric acid with formaldehyde, formic acid or sucrose. (1) As nitric acid is decomposed from azeotropic composition to 12N, about 90% of I2 is evolved from the solution of IO3-. (2) The addition of formaldehyde or formic acid as a decomposing agent lowers the iodine residue in solution to less than 1% with the progressing decomposition of nitric acid to about 2N. (3) With sucrose as a decomposing agent, it takes a few hours to complete the reaction, which results in iodine reflux from a condenser. (J.P.N.)

1980-09-01

 
 
 
 
381

Variability of acid-base status in acetate-free biofiltration 84% versus bicarbonate dialysis.  

Science.gov (United States)

The ultimate goal of hemodialysis (HD) treatment is to achieve the highest level of efficacy in the presence of maximal clinical tolerance. With an aim to offer good hemodynamic stability, as observed during the acetate-free biofiltration 14% (AFB 14%) to patients who are intolerant to bicarbonate dialysis (BD) and with less cost, we have developed since June 1994, a new HD technique, namely AFB 84%. This study was carried out to analyze acid-base variations during the AFB 84% in comparison to BD in hemodynamically stable patients on regular HD. This was a prospective randomized crossover study carried out on 12 patients (6 males and 6 females) for a total of 144 HD sessions (72 BD and 72 AFB 84%). Patients with decompensated cardiomyopathy, respiratory diseases or uncontrolled hypertension were not included in the trial. All the patients were treated with BD or AFB 84%; the latter is characterized by the absence of acetate in the dialysate and a complete correction of buffer balance by post-dilutional infusion of bicarbonate-based replacement solution. The comparison of pre-dialysis arterial acid-base and blood-gas parameters revealed no significant differences of pH, HCO(3)(-) and paCO(2) levels between the two techniques. Analysis of post-dialysis parameters showed that, among patients dialyzed with BD, there was over correction of metabolic acidosis with a tendency towards metabolic alkalosis. In contrast, in patients dialyzed with AFB 84%, we observed a significant improvement in pH and HCO(3)(-) levels but the increase in paCO(2) level was not significant. A comparison of these parameters between the two techniques showed statistically significant difference in pH, HCO(3)(-) and paCO(2) levels, but not for paO(2) level. AFB 84% can offer some important advantages with the complete absence of acetate from the substitution fluids, and permits a better correction of metabolic acidosis than BD, without causing alkalosis. PMID:18310870

Harzallah, Kais; Hichri, Nourredine; Mazigh, Chakib; Tagorti, Mohamed; Hmida, Ahmed; Hmida, Jalel

2008-03-01

382

Variability of Acid-Base Status in Acetate-Free Biofiltration 84% versus Bicarbonate Dialysis  

Directory of Open Access Journals (Sweden)

Full Text Available The ultimate goal of hemodialysis (HD treatment is to achieve the highest level of efficacy in the presence of maximal clinical tolerance. With an aim to offer good hemodynamic stability, as observed during the acetate-free biofiltration 14% (AFB 14% to patients who are intolerant to bicarbonate dialysis (BD and with less cost, we have developed since June 1994, a new HD technique, namely AFB 84%. This study was carried out to analyze acid-base variations during the AFB 84% in comparison to BD in hemodynamically stable patients on regular HD. This was a prospective randomized crossover study carried out on 12 patients (6 males and 6 females for a total of 144 HD sessions (72 BD and 72 AFB 84%. Patients with decompensated cardiomyopathy, respiratory diseases or uncontrolled hypertension were not included in the trial. All the patients were treated with BD or AFB 84%; the latter is characterized by the absence of acetate in the dialysate and a complete correction of buffer balance by post-dilutional infusion of bicarbonate-based replacement solution. The comparison of pre-dialysis arterial acid-base and blood-gas parameters revealed no significant differences of pH, HCO 3 - and paCO 2 levels between the two techniques. Analysis of post-dialysis parameters showed that, among patients dialyzed with BD, there was over correction of metabolic acidosis with a tendency towards metabolic alkalosis. In contrast, in patients dialyzed with AFB 84%, we observed a significant improvement in pH and HCO 3 - levels but the increase in paCO2 level was not significant. A comparison of these parameters between the two techniques showed statistically significant difference in pH, HCO3 - and paCO2 levels, but not for paO2 level. AFB 84% can offer some important advantages with the complete absence of acetate from the substitution fluids, and permits a better correction of metabolic acidosis than BD, without causing alkalosis.

Harzallah Kais

2008-01-01

383

Seasonality Influence in the Distribution of Formic and Acetic Acids in the Urban Atmosphere of São Paulo City, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Ambient levels and diurnal profiles of formic and acetic acids were measured in the atmosphere of São Paulo City in winter and spring 1996. A comparison between two different urban sites was done. Results demonstrate that carboxylic acid levels were affected by seasonality in the site with high vehicular emission density, while no seasonal influence was observed for the other site studied. Ranges of mixing ratios from 0.64 to 11.8 ppbv for formic acid and 0.51 to 10.7 ppbv for acetic acid were recorded. The results concerning the carboxylic acid concentrations were discussed with respect to direct emission and in situ photochemical production.

Souza Silvia R.

2001-01-01

384

Enhancement of organic solar cells efficiency with acetic acid modulated poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) buffer layers.  

Science.gov (United States)

Bulk-heterojunction organic solar cells (OSCs) based on poly(3-hexylthiophene) as a donor material and (6.6) phenyl-C61-butyric acid methyl ester as an acceptor material were investigated using a poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) buffer layer that was modulated with acetic acid. The 1.71 x 10(-1) omega x cm resistivity of the pristine PEDOT:PSS film decreased to 2.29 x 10(-2) omega x cm when acetic acid was applied. This modified PEDOT:PSS buffer layer improved the power conversion efficiency (PCE) of OSCs by reducing their already low series resistance and contact resistance. The PCE of OSCs in which the PEDOT:PSS buffer layers had been treated with acetic acid was 2.91%, an improvement over the 1.82% PCE for cells with pristine PEDOT:PSS layers. We optimized the ratio of acetic acid and PEDOT:PSS solution for high PCE of OSCs in this manuscript. The value of this modification method for hole transporting layer is clearly demonstrated and be applicable to other organic devices. PMID:24758027

Oh, Sang Hoon; Heo, Seung Jin; Kim, Hyun Jae

2014-07-01

385

Effect of acetic acid present in bagasse hydrolysate on the activities of xylose reductase and xylitol dehydrogenase in Candida guilliermondii.  

Science.gov (United States)

The first two steps in xylose metabolism are catalyzed by NAD(P)H-dependent xylose reductase (XR) (EC 1.1.1.21) and NAD(P)-dependent xylitol dehydrogenase (XDH) (EC 1.1.1.9), which lead to xylose-->xylitol-->xylulose conversion. Xylitol has high commercial value, due to its sweetening and anticariogenic properties, as well as several clinical applications. The acid hydrolysis of sugarcane bagasse allows the separation of a xylose-rich hemicellulosic fraction that can be used as a substrate for Candida guilliermondii to produce xylitol. However, the hydrolysate contains acetic acid, an inhibitor of microbial metabolism. In this study, the effect of acetic acid on the activities of XR and XDH and on xylitol formation by C. guilliermondii were studied. For this purpose, fermentations were carried out in bagasse hydrolysate and in synthetic medium. The activities of XR and XDH were higher in the medium containing acetic acid than in control medium. Moreover, none of the fermentative parameters were significantly altered during cell culture. It was concluded that acetic acid does not interfere with xylitol formation since the increase in XR activity is proportional to XDH activity, leading to a greater production of xylitol and its subsequent conversion to xylulose. PMID:15107950

Lima, Luanne Helena Augusto; das Graças de Almeida Felipe, Maria; Vitolo, Michele; Torres, Fernando Araripe Gonçalves

2004-11-01

386

[Aminomethyl derivatives of (benzisothiazolin-3-one-2-yl)acetic acid amides and 2-(1,2-benzisothiazoline-3-one-2-yl)propionic acid amides].  

Science.gov (United States)

In the search for pharmacological active new derivatives of 1,2-benzisothiazolin-3-on amides of (3-oxo-1,2-benzisothiazolin-2-yl)acetic acid and 3-(3-oxo-1,2-benzisothiazolin-2-yl)propionic acid were obtained. In the reaction of these amides with formaldehyde and various second aryl amines the title compounds are formed. Morpholinmethylamide of (3-oxo-1,2-benzisothiazolin-2-yl)acetic acid showed activity against Trichomonas vaginalis. In the reaction of ethyl esters of (3-oxo-1,2-benzisothiazolin-2-yl) acetic- and -propionic acids with hydrazine hydrate products of ring-opening of isothiazole-2,2'-dithio-bis [N- (ethoxycarbonylmethyl)benzamide] and 2,2'-dithio-bis[N-(ethoxycarbonylethyl)benzamide are formed. PMID:1811228

S?awik, T

1991-11-01

387

Primary and secondary kinetic isotope effects in the acid-catalyzed dehydration of 1,1'-diadamantylmethylcarbinol in aqueous acetic acid  

International Nuclear Information System (INIS)

The sulfuric acid catalyzed dehydration of 1,1'-diadamantyl-methylcarbinol in anhydrous acetic acid proceeds exclusively to 1,1'-bis(1-adamantyl)ethylene. The secondary deuterium isotope effect of 1.32 found for this reaction shows that carbonium ion formation from the protonated alcohol is rate determining. In the presence of water, however, capture of the carbonium ion competes with deprotonation, introducing a primary isotope effect. Consequently, the overall KIE rises, reaching 3.18 for 80% aqueous acetic acid. Analysis of the KIE for 80 to 100% aqueous acetic acid is consistent with a simple classical mechanism involving reversible formation of the intermediate carbonium ion. The primary isotope effect upon deprotonation is at the most 2.98, indicative of an asymmetric transition state close to the carbonium ion

1981-01-16

388

Oxidation of fatty acid may be enhanced by a combination of pomegranate fruit phytochemicals and acetic acid in HepG2 cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigated whether the combination of phytochemicals and acetic acid in the form of fruit vinegar provides an additive effect on changes of mRNA levels related to fatty acid oxidation in human hepatocyte (HepG2). Among the seven fruit vinegars (Rubuscoreanus, Opuntia, blueberry, cherry, red ginseng, mulberry, and pomegranate) studied, treatment of HepG2 with pomegranate vinegar (PV) at concentrations containing 1 mM acetic acid showed the highest in vitro potentiating effect on the mRNA ...

Kim, Ji Yeon; Ok, Elly; Kim, You Jin; Choi, Kyoung-sook; Kwon, Oran

2013-01-01

389

Gluconacetobacter medellinensis sp. nov., cellulose- and non-cellulose-producing acetic acid bacteria isolated from vinegar.  

Science.gov (United States)

The phylogenetic position of a cellulose-producing acetic acid bacterium, strain ID13488, isolated from commercially available Colombian homemade fruit vinegar, was investigated. Analyses using nearly complete 16S rRNA gene sequences, nearly complete 16S-23S rRNA gene internal transcribed spacer (ITS) sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, allocated the micro-organism to the genus Gluconacetobacter, and more precisely to the Gluconacetobacter xylinus group. Moreover, the data suggested that the micro-organism belongs to a novel species in this genus, together with LMG 1693(T), a non-cellulose-producing strain isolated from vinegar by Kondo and previously classified as a strain of Gluconacetobacter xylinus. DNA-DNA hybridizations confirmed this finding, revealing a DNA-DNA relatedness value of 81?% between strains ID13488 and LMG 1693(T), and values strain LMG 1693(T) and the type strains of the closest phylogenetic neighbours. Additionally, the classification of strains ID13488 and LMG 1693(T) into a single novel species was supported by amplified fragment length polymorphism (AFLP) and (GTG)5-PCR DNA fingerprinting data, as well as by phenotypic data. Strains ID13488 and LMG 1693(T) could be differentiated from closely related species of the genus Gluconacetobacter by their ability to produce 2- and 5-keto-d-gluconic acid from d-glucose, their ability to produce acid from sucrose, but not from 1-propanol, and their ability to grow on 3?% ethanol in the absence of acetic acid and on ethanol, d-ribose, d-xylose, sucrose, sorbitol, d-mannitol and d-gluconate as carbon sources. The DNA G+C content of strains ID13488 and LMG 1693(T) was 58.0 and 60.7 mol%, respectively. The major ubiquinone of LMG 1693(T) was Q-10. Taken together these data indicate that strains ID13488 and LMG 1693(T) represent a novel species of the genus Gluconacetobacter for which the name Gluconacetobacter medellinensis sp. nov. is proposed. The type strain is LMG 1693(T) (?=?NBRC 3288(T)?=?Kondo 51(T)). PMID:22729025

Castro, Cristina; Cleenwerck, Ilse; Trcek, Janja; Zuluaga, Robin; De Vos, Paul; Caro, Gloria; Aguirre, Ricardo; Putaux, Jean-Luc; Gañán, Piedad

2013-03-01

390

Removal of paralytic shellfish toxins by probiotic lactic Acid bacteria.  

Science.gov (United States)

Paralytic shellfish toxins (PSTs) are non-protein neurotoxins produced by saltwater dinoflagellates and freshwater cyanobacteria. The ability of Lactobacillus rhamnosus strains GG and LC-705 (in viable and non-viable forms) to remove PSTs (saxitoxin (STX), neosaxitoxin (neoSTX), gonyautoxins 2 and 3 (GTX2/3), C-toxins 1 and 2 (C1/2)) from neutral and acidic solution (pH 7.3 and 2) was examined using HPLC. Binding decreased in the order of STX ~ neoSTX > C2 > GTX3 > GTX2 > C1. Removal of STX and neoSTX (77%-97.2%) was significantly greater than removal of GTX3 and C2 (33.3%-49.7%). There were no significant differences in toxin removal capacity between viable and non-viable forms of lactobacilli, which suggested that binding rather than metabolism is the mechanism of the removal of toxins. In general, binding was not affected by the presence of other organic molecules in solution. Importantly, this is the first study to demonstrate the ability of specific probiotic lactic bacteria to remove PSTs, particularly the most toxic PST-STX, from solution. Further, these results warrant thorough screening and assessment of safe and beneficial microbes for their usefulness in the seafood and water industries and their effectiveness in vivo. PMID:25046082

Vasama, Mari; Kumar, Himanshu; Salminen, Seppo; Haskard, Carolyn A

2014-07-01

391

Removal of plutonium from nitric acid-oxalic acid solutions using anion exchange method  

International Nuclear Information System (INIS)

An anion exchange method using Amberlyst A-26 (MP) resin was developed for removal of Pu from nitric acid-oxalic acid solutions without destroying oxalate. The method consists of sorption of Pu(IV) on Amberlyst A-26, a macroporous anion exchange resin, from nitric acid-oxalic acid medium in the presence of Al(NO3)3. Pu(IV) breakthrough capacity of Amberlyst A-26 using synthetic feed solution was determined. (author)

1999-01-01

392

Calibration and intercomparison of acetic acid measurements using proton-transfer-reaction mass spectrometry (PTR-MS)  

Science.gov (United States)

Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitations of available measurement techniques. This paper demonstrates that, when properly calibrated, proton-transfer-reaction mass spectrometry (PTR-MS) can be a valuable technique for fast response, accurate quantification of acetic acid in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv-1) at a drift tube field strength of 132 Townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Acetic acid was measured with PTR-MS on Appledore B Island, ME, during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign and validated based on acetic acid measured in parallel using tandem mist chambers coupled with ion chromatography (MC/IC). Mixing ratios ranged from a minimum of 0.075 ± 0.004 ppbv to 3.555 ± 0.171 ppbv, with a median mixing ratio of 0.530 ± 0.025 ppbv. An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?), an intercept of 0.049 ± 0.020 (2?) ppbv, and an R2 of 0.78.

Haase, K. B.; Keene, W. C.; Pszenny, A. A. P.; Mayne, H. R.; Talbot, R. W.; Sive, B. C.

2012-11-01

393

Calibration and intercomparison of acetic acid measurements using proton-transfer-reaction mass spectrometry (PTR-MS  

Directory of Open Access Journals (Sweden)

Full Text Available Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitations of available measurement techniques. This paper demonstrates that, when properly calibrated, proton-transfer-reaction mass spectrometry (PTR-MS can be a valuable technique for fast response, accurate quantification of acetic acid in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv?1 at a drift tube field strength of 132 Townsend (Td. Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Acetic acid was measured with PTR-MS on Appledore B Island, ME, during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT campaign and validated based on acetic acid measured in parallel using tandem mist chambers coupled with ion chromatography (MC/IC. Mixing ratios ranged from a minimum of 0.075 ± 0.004 ppbv to 3.555 ± 0.171 ppbv, with a median mixing ratio of 0.530 ± 0.025 ppbv. An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?, an intercept of 0.049 ± 0.020 (2? ppbv, and an R2 of 0.78.

K. B. Haase

2012-11-01

394

The Effect of Curcumin (Active Substance of Turmericon the Acetic Acid-Induced Visceral Nociception in Rats  

Directory of Open Access Journals (Sweden)

Full Text Available In the present study, the effect of chronic oral administration of curcumin in the presence or absence of morphine and noloxone was investigated on the visceral nociception induced by acetic acid in rats. Intraperitoneal injection of acetic acid (1 mL, 2% produced contractions in the abdominal musculature (writhes. The latency time to the beginning of the first writhe was measured and the total number of writhes in the 1 h after acetic acid injection was counted. The latency time to the beginning of the first writhe was significantly (p<0.05 increased and the number of writhes was significantly (p<0.05 decreased by curcumin (20 and 40 mg kg-1 body weight. The same results were obtained after subcutaneous injection of morphine (1 mg kg-1 b.wt.. Naloxone at the dose of 1 mg kg-1 body weight had no effect on pain intensity. Curcumin significantly (p<0.05 enhanced the effect of morphine on the visceral pain responses, however did not reverse the effect of naloxone. Present data suggest that in the acetic acid-induced visceral nociception of rats, curcumin may produce an antinociceptive effect and the endogenous analgesic opioid system is involved in the curcumin-induced antinociception.

Hossein Tajik

2008-01-01

395

Production of acetic acid by hydrothermal two-step process of vegetable wastes for use as a road deicer  

International Nuclear Information System (INIS)

This study aimed to produce acetic acid from vegetable wastes by a new hydrothermal two-step process. A continuous flow reaction system with a maximum treatment capacity of 2 kg/h of dry biomass developed by us was used. Five kinds of vegetables of carrots, white radish, chinese cabbage, cabbage and potato were selected as the representation of vegetable wastes. First, batch experiments with the selected vegetables were performed under the condition of 300 deg. C, 1 min for the first step, and 300 deg. C, 1 min and 70% oxygen supply for the second step, which is the optimum condition for producing acetic acid in the case of using starch as test material. The highest yields of acetic acid from five vegetables were almost the same as those obtained from starch. Subsequently, similar the highest yield of acetic acid and experimental conditions from vegetables were also obtained successfully using the continuous flow reaction system. These results should be useful for developing an industrial scale process

2008-07-01

396

Metal-organic coordination architectures of azole heterocycle ligands bearing acetic acid groups: Synthesis, structure and magnetic properties  

International Nuclear Information System (INIS)

Four new coordination complexes with azole heterocycle ligands bearing acetic acid groups, [Co(L1)2]n (1), [CuL1N3]n (2), [Cu(L2)2.0.5C2H5OH.H2O]n (3) and [Co(L2)2]n (4) (here, HL1=1H-imidazole-1-yl-acetic acid, HL2=1H-benzimidazole-1-yl-acetic acid) have been synthesized and structurally characterized. Single-crystal structure analysis shows that 3 and 4 are 2D complexes with 44-sql topologies, while another 2D complex 1 has a (43)2(46)-kgd topology. And 2 is a 3D complex composed dinuclear ?1,1-bridging azido CuII entities with distorted rutile topology. The magnetic properties of 1 and 2 have been studied. - Graphical Abstract: The synthesis, crystal structure, and magnetic properties of the new coordination complexes with azole heterocycle ligands bearing acetic acid groups are reported.

2009-10-01

397

5-MERCAPTOTETRAZOLE-1-ACETIC Acid as a Novel Capping Ligand for Stabilization of Metal Nanoparticles in Water  

Science.gov (United States)

The novel stabilizing ligand, 5-mercaptotetrazole-1-acetic acid, has been applied for synthesis of silver and palladium nanoparticles in aqueous media. The morphology of the synthesized particles and some properties were determined by TEM, FTIR and UV-visible spectroscopy, thermogravimetric analysis and quantum-chemical calculations.

Nichick, M. N.; Voitekhovich, S. V.; Matulis, V. E.; Komsa, D. N.; Lesnikovich, A. I.; Ivashkevich, O. A.

2013-05-01

398

Competitive fragmentation pathways of acetic acid dimer explored by synchrotron VUV photoionization mass spectrometry and electronic structure calculations  

International Nuclear Information System (INIS)

In present study, photoionization and dissociation of acetic acid dimers have been studied with the synchrotron vacuum ultraviolet photoionization mass spectrometry and theoretical calculations. Besides the intense signal corresponding to protonated cluster ions (CH3COOH)n·H+, the feature related to the fragment ions (CH3COOH)H+·COO (105 amu) via ?-carbon-carbon bond cleavage is observed. By scanning photoionization efficiency spectra, appearance energies of the fragments (CH3COOH)·H+ and (CH3COOH)H+·COO are obtained. With the aid of theoretical calculations, seven fragmentation channels of acetic acid dimer cations were discussed, where five cation isomers of acetic acid dimer are involved. While four of them are found to generate the protonated species, only one of them can dissociate into a C–C bond cleavage product (CH3COOH)H+·COO. After surmounting the methyl hydrogen-transfer barrier 10.84 ± 0.05 eV, the opening of dissociative channel to produce ions (CH3COOH)+ becomes the most competitive path. When photon energy increases to 12.4 eV, we also found dimer cations can be fragmented and generate new cations (CH3COOH)·CH3CO+. Kinetics, thermodynamics, and entropy factors for these competitive dissociation pathways are discussed. The present report provides a clear picture of the photoionization and dissociation processes of the acetic acid dimer in the range of the photon energy 9–15 eV.

2012-09-28

399

EPR spectroscopy investigation of copper (II) complexes with (0.0-dialkyl dithiophosphate)-acetic and undecanoic acids  

International Nuclear Information System (INIS)

By electron paramagnetic resonance spectroscopy the copper (II) complexes with (0.0-dialkyl dithiophosphate)-acetic and undecanoic acids were investigated. It was determined that these complexes divided on two structure types: dimeric (with four bridge ligands) and monomeric. In all cases ligands was coordinated by carboxylic groups.

1992-01-01

400

ETHANOL, ACETIC ACID, AND WATER ADSORPTION FROM BINARY AND TERNARY LIQUID MIXTURES ON HIGH-SILICA ZEOLITES  

Science.gov (United States)

Adsorption isotherms were measured for ethanol, acetic acid, and water adsorbed on high-silica ZSM-5 zeolite powder from binary and ternary liquid mixtures at room temperature. Ethanol and water adsorption on two high-silica ZSM-5 zeolites with different aluminum contents and a h...

 
 
 
 
401

Importance of the surrounding colonic mucosa in distinguishing between hyperplastic and adenomatous polyps during acetic acid chromoendoscopy  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: To examine the characteristics of colonic polyps, where it is difficult to distinguish adenomatous polyps from hyperplastic polyps, with the aid of acetic acid chromoendosc