WorldWideScience
 
 
1

REMOVING IODOBENZENE COMPOUNDS FROM ACETIC ACID  

UK PubMed Central (United Kingdom)

A method for removing iodobenzene compounds from an acetic acid is disclosed. The method comprises contacting an acetic acid with palladium supported on macroreticular ion-exchange resins. A process for producing acetic acid is also disclosed. The process comprises carbonylating methanol in the presence of a carbonylation catalyst and a triphenylphosphine oxide stabilizer to produce acetic acid which contains iodobenzene compounds and removing the iodobenzene compounds by contacting the acetic acid product with palladium.

WANG WEI

2

Removing iodobenzene compounds from acetic acid  

UK PubMed Central (United Kingdom)

A method for removing iodobenzene compounds from an acetic acid is disclosed. The method comprises contacting an acetic acid with palladium supported on macroreticular ion-exchange resins. A process for producing acetic acid is also disclosed. The process comprises carbonylating methanol in the presence of a carbonylation catalyst and a triphenylphosphine oxide stabilizer to produce acetic acid which contains iodobenzene compounds and removing the iodobenzene compounds by contacting the acetic acid product with palladium.

WANG WEI

3

METHOD FOR REMOVING IODINE COMPOUND FROM ACETIC ACID  

UK PubMed Central (United Kingdom)

The present invention discloses a method for removing iodine compounds from acetic acid, in which the iodine compound is removed by using a solid adsorbent in the form of an activated carbon fiber having a large strength, a large bulk density, and a large specific surface, so that the treatment of large amounts should be possible, that the acetic acid should not be contaminated during the extraction of foreign materials from the adsorbent, and that the adsorbent can be repeatedly used by regenerating it. The method includes the steps of: preparing a filter in the usual manner by using an activated carbon fiber as the adsorbent; and making acetic acid containing an iodide pass through the activated carbon fiber filter, whereby the iodide in acetic acid is removed by being adsorbed by the activated carbon fiber filter.

YANG O BONG; KIM YOUNG GUL; KIM JAE CHANG; LEE JAE SUNG; YANG HEE JUNG

4

Development of Acetic Acid Removal Technology for the UREX (plus) Process.  

Science.gov (United States)

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 su...

J. S. Watson R. M. Counce

2009-01-01

5

Treatment of gases to remove acetic acid and carbon monoxide in absorptive-catalytic mode  

Energy Technology Data Exchange (ETDEWEB)

The aim of the present study is to develop an efficient method for removing simultaneously present impurities of acetic acid and carbon monoxide from gases. Treatment of gases with manganese and cobalt oxide catalysts supported by mordenite to remove acetic acid and carbon monoxide present separately or simultaneously was studied.

Solov`ev, S.A.; Belokleitseva, G.M.; Vlasenko, V.M. [L.V. Pisarzhevskii Institute of Physical Chemistry, Kiev (Ukraine)

1995-02-20

6

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

7

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 a...

Moura, A. Vilela; Schuller, Dorit; Faia, A. Mendes; Côrte-Real, Manuela

8

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

9

PREPARATION OF ACETIC ACID AND ACETIC ANHYDRIDE  

UK PubMed Central (United Kingdom)

Disclosed is a process for the preparation of acetic acid and acetic anhydride. The process comprises carbonylating dimethyl carbonate. The carbonylation reaction for producing acetic acid is performed in the presence of water, while the carbonylation for producing acetic anhydride is performed essentially in the absence of water.

GUO SHAO-HUA; BRTKO WAYNE J; HALLINAN NOEL; SALISBURY BRIAN A

10

Preparation of acetic acid and acetic anhydride  

UK PubMed Central (United Kingdom)

Disclosed is a process for the preparation of acetic acid and acetic anhydride. The process comprises carbonylating dimethyl carbonate. The carbonylation reaction for producing acetic acid is performed in the presence of water, while the carbonylation for producing acetic anhydride is performed essentially in the absence of water.

GUO SHAO-HUA; BRTKO WAYNE J; HALLINAN NOEL; SALISBURY BRIAN A

11

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

12

PURIFICATION OF ACETIC ACID FROM WOOD ACETYLATION PROCESS  

UK PubMed Central (United Kingdom)

Disclosed is a method of purifying acetic acid containing terpene and terpenoid impurities, comprising: (a) supplying acetic acid containing terpene or terpenoid impurities and water to a distillation column (b) azeotropically removing terpene or terpenoid impurities from the mixture of acetic acid and water supplied to the column as distillate and (c) withdrawing a product stream from the column comprising acetic acid purified of terpene or terpenoid impurities.

WARNER R

13

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,

14

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

15

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

16

Comparative evaluation of 15% ethylenediamine tetra-acetic acid plus cetavlon and 5% chlorine dioxide in removal of smear layer: A scanning electron microscope study.  

UK PubMed Central (United Kingdom)

AIMS: The purpose of this study was to compare the efficacy of smear layer removal by 5% chlorine dioxide and 15% Ethylenediamine Tetra-Acetic Acid plus Cetavlon (EDTAC) from the human root canal dentin. MATERIALS AND METHODS: Fifty single rooted human mandibular anterior teeth were divided into two groups of 20 teeth each and control group of 10 teeth. The root canals were prepared till F3 protaper and initially irrigated with 2% Sodium hypochlorite followed by 1 min irrigation with 15% EDTAC or 5% Chlorine dioxide respectively. The control group was irrigated with saline. The teeth were longitudinally split and observed under Scanning electron microscope SEM (×2000). STATISTICAL ANALYSIS USED: The statistical analysis was done using General Linear Mixed Model. RESULTS: At the coronal thirds, no statistically significant difference was found between 15% EDTAC and 5% Chlorine dioxide in removing smear layer. In the middle and apical third region 15% EDTAC showed better smear layer removal ability than 5% Chlorine dioxide. CONCLUSION: Final irrigation with 15% EDTAC is superior to 5% chlorine dioxide in removing smear layer in the middle and apical third of radicular dentin.

Singh S; Arora V; Majithia I; Dhiman RK; Kumar D; Ather A

2013-01-01

17

Acetic acid dinbutyl phthalate technology  

UK PubMed Central (United Kingdom)

The invention discloses an acetic acid dinbutyl phthalate technology. A novel catalyst with solid acid rather than sulfuric acid is used and produced into filler and a reaction rectification tower iscomposed of three parts, wherein the upper part is a rectification section with backflow and rectification function and common filler is stilled used and tubular heat exchangers are arranged in the tower to condense the partly-ascending gas as the backflow liquid, thus backflow is realized in the rectification tower.

WANGLIN YU

18

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 fermenta...

Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

19

SYSTEM AND METHOD FOR ACETIC ACID DEHYDRATION  

UK PubMed Central (United Kingdom)

A cost effective and energy efficient distillation technique for recovering acetic acid from a waste water stream containing acetic acid and water generated during terephthalic acid production employs a liquid-liquid extraction column and a downstream dehydration distillation column that operates under azeotropic or conventional distillation conditions to recover the acetic acid. The liquid-liquid extraction column produces an extract containing extraction solvent and acetic acid which is fed to the dehydration distillation column where the extraction solvent and acetic acid are separated. The dehydration distillation column can employ a condenser system for energy recovery. The condenser system can be a steam generator that condenses vapor into a concentrated acetic acid stream and generates low pressure steam. Any remaining acetic acid in the water is treated.

JAMG JI YOUNG; WU KUANG YEU

20

System and method for acetic acid dehydration  

UK PubMed Central (United Kingdom)

Disclosed is a distillation system and method for recovering acetic acid from a feed stream containing acetic acid and water stream generated during terephthalic acid production. The invention includes a liquid-liquid extraction column and a dehydration distillation column utilizing azeotropic distillation or conventional to recover the acetic acid. The liquid-liquid extraction column is installed upstream from the dehydration distillation column. The liquid-liquid extraction column produces an extract of an extraction solvent and acetic acid which is sent to the dehydration distillation column to separate the extraction solvent and acetic acid. The dehydration distillation column may be used with or without a condenser system to recover the energy. The condenser system is a steam generator that condenses the vapor into a concentrated acetic acid stream while generating a low pressure steam. Any remaining acetic acid in water is sent to a waste water recycling facility.

YOUNG JAMG JI; YEU WU KUANG

 
 
 
 
21

Extractive fermentation of acetic acid  

Energy Technology Data Exchange (ETDEWEB)

In this technoeconomic evaluation of the manufacture of acetic acid by fermentation, the use of the bacterium: Acetobacter suboxydans from the old vinegar process was compared with expected performance of the newer Clostridium thermoaceticum bacterium. Both systems were projected to operate as immobilized cells in a continuous, fluidized bed bioreactor, using solvent extraction to recover the product. Acetobacter metabolizes ethanol aerobically to produce acid at 100 g/L in a low pH medium. This ensures that the product is in the form of a concentrated extractable free acid, rather than as an unextractable salt. Unfortunately, yields from glucose by way of the ethanol fermentation are poor, but near the biological limits of the organisms involved. Conversely, C. thermoaceticum is a thermophilic anaerobe that operates at high fermentation rates on glucose at neutral pH to produce acetate salts directly in substantially quantitative yields. However, it is severely inhibited by product, which restricts concentration to a dilute 20 g/L. An improved Acetobacter system operating with recycled cells at 50 g/L appears capable of producing acid at $0.38/lb, as compared with a $0.29/lb price for synthetic acid. However, this system has only a limited margin for process improvement. The present Clostridium system cannot compete, since the required selling price would be $0.42/lb. However, if the organism could be adapted to tolerate higher product concentrations at acid pH, selling price could be reduced to $0.22/lb, or about 80% of the price of synthetic acid.

Busche, R.M. [Bio En-Gene-Er Associates, Inc., Wilmington, DE (United States)

1991-12-31

22

Microbial removal of acetate selectively from sugar mixtures.  

Science.gov (United States)

Acetic acid is an unavoidable constituent of the biomass hydrolysates generated from acetylated hemicellulose and lignin, and acetate affects the performance of microbes used to convert these hydrolysates into biofuels or other biochemicals. In this study, acetate was selectively removed from synthetic mixtures of glucose and xylose using metabolically engineered Escherichia coli strains having mutations in the glucose phosphotransferase system (PTS) genes (ptsG, manZ, crr), glucokinase (glk), and xylose (xylA). In batch culture, ALS1060 (ptsG manZ glk xylA) consumed exclusively acetate to depletion, and then consumed the two sugars only at a very slow rate (a growth rate of about 0.01 h(-1)). We also examined the effects of an additional knockout of either malX, fruA, fruB, bglF, or crr, genes that are involved in other PTSs, and a batch process using KD840 (ptsG manZ glk crr xylA) demonstrated a further reduction in glucose or xylose consumption by E. coli. These results demonstrate the feasibility of using a substrate-selective approach for the pre-treatment of biomass hydrolysate for microbial processes. PMID:21225311

Lakshmanaswamy, Arun; Rajaraman, Eashwar; Eiteman, Mark A; Altman, Elliot

2011-01-12

23

Microbial removal of acetate selectively from sugar mixtures.  

UK PubMed Central (United Kingdom)

Acetic acid is an unavoidable constituent of the biomass hydrolysates generated from acetylated hemicellulose and lignin, and acetate affects the performance of microbes used to convert these hydrolysates into biofuels or other biochemicals. In this study, acetate was selectively removed from synthetic mixtures of glucose and xylose using metabolically engineered Escherichia coli strains having mutations in the glucose phosphotransferase system (PTS) genes (ptsG, manZ, crr), glucokinase (glk), and xylose (xylA). In batch culture, ALS1060 (ptsG manZ glk xylA) consumed exclusively acetate to depletion, and then consumed the two sugars only at a very slow rate (a growth rate of about 0.01 h(-1)). We also examined the effects of an additional knockout of either malX, fruA, fruB, bglF, or crr, genes that are involved in other PTSs, and a batch process using KD840 (ptsG manZ glk crr xylA) demonstrated a further reduction in glucose or xylose consumption by E. coli. These results demonstrate the feasibility of using a substrate-selective approach for the pre-treatment of biomass hydrolysate for microbial processes.

Lakshmanaswamy A; Rajaraman E; Eiteman MA; Altman E

2011-09-01

24

Cytenamide trifluoro­acetic acid solvate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cytenamide forms a 1:1 solvate with trifluoro­acetic acid (systematic name: 5H-dibenzo[a,d]cyclo­hepta­triene-5-carboxamide trifluoro­acetic acid solvate), C16H13NO·C2HF3O2. The compound crystallizes with one mol­ecule of cytenamide and one of trifluoro­acetic acid in the asymmetric unit; these are ...

Johnston, Andrea; Florence, Alastair J.; Fabbiani, Francesca J. A.; Shankland, Kenneth; Bedford, Colin T.; Bardin, Julie

25

Improvement of productivity in acetic acid fermentation with Clostridium thermoaceticum  

Energy Technology Data Exchange (ETDEWEB)

Production of acetic acid by a mutant strain of Clostridium thermoaceticum was compared in three types of membrane cell-recycle bioreactors. A modified fed-batch bioreactor (where the product is partially removed at the end of fermentation, but the cells are retained), and a two-stage CSTR (with product being removed continuously and the cells being recycled from the second to the first stage) resulted in better performance than a one-stage CSTR or batch fermenter. The difference in performance was greater at higher acetate concentration. With 45 g/L of glucose in the feed, productivity was 0.75-1.12 g/L-h and acetic acid concentrations were 34-38 g/L. This is more than double the batch system. The nutrient supply rate also appeared to have a strong influence on productivity of the microorganism.

Shah, M.M.; Cheryan, M. [Univ. of Illinois, Urbana, IL (United States)

1995-12-31

26

Acetic acid mediated interactions between alumina surfaces  

International Nuclear Information System (INIS)

[en] 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

27

Genera and species in acetic acid bacteria.  

UK PubMed Central (United Kingdom)

Taxonomic studies of acetic acid bacteria were historically surveyed. The genus Acetobacter was first introduced in 1898 with a single species, Acetobacter aceti. The genus Gluconobacter was proposed in 1935 for strains with intense oxidation of glucose to gluconic acid rather than oxidation of ethanol to acetic acid and no oxidation of acetate. The genus "Acetomonas" was described in 1954 for strains with polar flagellation and no oxidation of acetate. The proposals of the two generic names were due to confusion, and "Acetomonas" was a junior subjective synonym of Gluconobacter. The genus Acetobacter was in 1984 divided into two subgenera, Acetobacter and Gluconoacetobacter. The latter was elevated to the genus Gluconacetobacter in 1998. In the acetic acid bacteria, ten genera are presently recognized and accommodated to the family Acetobacteraceae, the Alphaproteobacteria: Acetobacteer, Gluconobacter, Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia and Granulibacter. In contrast, the genus Frateuria, strains of which were once named 'pseudacetic acid bacteria', was classified into the Gammaproteobacteria. The genus Gluconacetobacter was phylogenetically divided into two groups: the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group. The two groups were discussed taxonomically.

Yamada Y; Yukphan P

2008-06-01

28

Genera and species in acetic acid bacteria.  

Science.gov (United States)

Taxonomic studies of acetic acid bacteria were historically surveyed. The genus Acetobacter was first introduced in 1898 with a single species, Acetobacter aceti. The genus Gluconobacter was proposed in 1935 for strains with intense oxidation of glucose to gluconic acid rather than oxidation of ethanol to acetic acid and no oxidation of acetate. The genus "Acetomonas" was described in 1954 for strains with polar flagellation and no oxidation of acetate. The proposals of the two generic names were due to confusion, and "Acetomonas" was a junior subjective synonym of Gluconobacter. The genus Acetobacter was in 1984 divided into two subgenera, Acetobacter and Gluconoacetobacter. The latter was elevated to the genus Gluconacetobacter in 1998. In the acetic acid bacteria, ten genera are presently recognized and accommodated to the family Acetobacteraceae, the Alphaproteobacteria: Acetobacteer, Gluconobacter, Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia and Granulibacter. In contrast, the genus Frateuria, strains of which were once named 'pseudacetic acid bacteria', was classified into the Gammaproteobacteria. The genus Gluconacetobacter was phylogenetically divided into two groups: the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group. The two groups were discussed taxonomically. PMID:18199517

Yamada, Yuzo; Yukphan, Pattaraporn

2007-12-05

29

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

2009-01-01

30

4,4?-Bipyridine acetic acid disolvate  

Directory of Open Access Journals (Sweden)

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

31

PROCESSES FOR MAKING ETHANOL FROM ACETIC ACID  

UK PubMed Central (United Kingdom)

A process for selective formation of ethanol from acetic acid by hydrogenating acetic acid in the presence of first metal, a silicaceous support, and at least one support modifier. Preferably, the first metal is selected from the group consisting of copper, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, titanium, zinc, chromium, rhenium, molybdenum, and tungsten. In addition the catalyst may comprise a second metal preferably selected from the group consisting of copper, molybdenum, tin, chromium, iron, cobalt, vanadium, tungsten, palladium, platinum, lanthanum, cerium, manganese, ruthenium, rhenium, gold, and nickel.

JOHNSTON VICTOR J; CHEN LAIYUAN; KIMMICH BARBARA F; CHAPMAN JOSEFINA T; ZINK JAMES H; WEINER HEIKO; POTTS JOHN L; JEVTIC RADMILA

32

Evaluación de la capacidad de adsorción de desechos agroindustriales para la remoción de ácido acético/ Evaluation of the adsorption capacity of agro-industrial waste for acetic acid removal  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Se evaluó la utilización de desechos agroindustriales: la cascarilla de arroz y el pergamino de café como adsorbentes alternativos para la remoción de ácido acético. Para ello se realizó su caracterización determinando la cantidad de humedad y cenizas, índice de acidez, y el análisis a través de espectrometría de absorción en el infrarrojo y la difracción de rayos X. Se construyeron las isotermas de adsorción de ácido acético sobre cascarilla de arroz, pe (more) rgamino de café y carbón activado como referencia, mediante el contacto en agitación de soluciones de ácido acético a diferentes concentraciones, realizándose 8 experiencias en las cuales se variaron los factores: tamaño de partícula de los adsorbentes, tratamiento de los materiales adsorbentes, tiempo de agitación y rango de concentraciones de ácido acético. Las isotermas de cascarilla de arroz y pergamino de café se ajustaron al modelo de Langmuir a un rango de concentración de ácido acético entre 0,03 y 0,25 mol/L, 1 hora de agitación y lavados del adsorbente con agua a 70 ºC y bicarbonato de sodio al 5% a 70 ºC. Se concluyó que la adsorción del ácido acético sobre cascarilla de arroz y pergamino de café ocurre mediante la formación de enlaces de hidrógeno entre el ácido y la superficie de estosmateriales gracias a la presencia de celulosa, hemicelulosa, lignina y óxido de silicio en su estructura, alcanzando entre un 40% y 70% de los rendimientos obtenidos con el carbón activado. Abstract in english The use of agro-industrial waste was evaluated; namely, rice husks and coffee parchment as alternative adsorbents for acetic acid removal. To this end, material characterization was carried out determining the amount of humidity and ashes, the acid value, and by absorption spectrometry analysis in infrared and x-ray diffraction. Isotherms of acetic acid adsorption on rice husks, coffee parchment and activated charcoal as a reference, were constructed, by means of contact (more) in agitation of different concentrations of solutions of acetic acid. Eight experiments were made in which the factors were varied:adsorbents particle size, adsorbent materials treatment, agitation time and rank of acetic acid concentrations. The rice husk isotherms and coffee parchment adjusted to the Langmuir model within a rank of acetic acid concentration between 0.03 and 0.25 mol/L, 1 hour of agitation and water and 5% sodium bicarbonate washings at 70 ºC. It was concluded that adsorption of acetic acid on rice husks and coffee parchment occurs through hydrogen bond formation between the acid and the surface of these materials because of the presence of cellulose, hemicelluloses, lignin and silicon oxide in its structure, reaching between 40% and 70% of the yields obtained with the activated charcoal.

HERNÁNDEZ, ROSÁNGELES; CARRASCO, PEDRO; MUJICA, ROSA; ESPÍNOLA, MARÍA

2007-01-01

33

Supported Ag nanoparticles as trace iodide adsorbent from acetic acid  

Science.gov (United States)

Ag nanoparticles (AgNPs) were used as adsorbent to remove trace iodide from acetic acid. Under identical conditions, AgNPs adsorbent with 0.5 wt % Ag has the same performance as commercial adsorbent with 10 wt % Ag+. In addition, Ag loss of AgNPs adsorbent is remarkably lower than that of commercial adsorbent. The Ag content in AgNPs adsorbent affects its adsorption performance, and the optimal content is 1.0 wt %. Saturated AgNPs adsorbent can be regenerated by hydrogen reduction and reused with satisfying performance. The properties of AgNPs adsorbent are based on surface effect of nanoparticles, differing from commercial Ag+ type adsorbents. In a word, AgNPs adsorbent is of high efficiency, low Ag loss and easy recycling, thus making it "green adsorbent" for removing iodide from acetic acid.

Qian, Qingli; Shao, Shouyan; Yan, Fang; Ling, Chen; Yan, Fengwen; Cao, Hongbing; Guo, Cun-Yue; Yuan, Guoqing

2012-09-01

34

APPARATUS AND METHOD FOR RECOVERY OF ACETIC ACID FROM AN AQUEOUS SOLUTION THEREOF  

UK PubMed Central (United Kingdom)

The invention disclosed relates to an apparatus and method for recovering acetic acid from an aqueous feed stream containing acetic acid, in particular a stream generated during terephthalic acid production. The apparatus includes: a liquid-liquid extraction column to which water-rich feed streams are fed, having a guard bed situated near the top and within the extraction column for conversion by reaction with acetic acid of alcohol within the mixture to the corresponding ester and an azeotropic distillation column to remove residual water from acetic acid, to which water-poor feed streams are fed directly at a height of the azeotropic distillation column at which the mixture therein has a similar water concentration. The liquid-liquid extraction column produces an extract comprising an extraction solvent and acetic acid which is sent to the azeotropic distillation column to separate residual water and acetic acid.

JANG JI-YOUNG; WU KUANG-YEU; CHUANG KARL TZE-TANG

35

Apparatus and method for recovery of acetic acid from an aqueous solution thereof  

UK PubMed Central (United Kingdom)

The invention disclosed relates to an apparatus and method for recovering acetic acid from an aqueous feed stream containing acetic acid, in particular a stream generated during terephthalic acid production. The apparatus includes: a liquid-liquid extraction column to which water-rich feed streams are fed, having a guard bed situated near the top and within the extraction column for conversion by reaction with acetic acid of alcohol within the mixture to the corresponding ester and an azeotropic distillation column to remove residual water from acetic acid, to which water-poor feed streams are fed directly at a height of the azeotropic distillation column at which the mixture therein has a similar water concentration. The liquid-liquid extraction column produces an extract comprising an extraction solvent and acetic acid which is sent to the azeotropic distillation column to separate residual water and acetic acid.

JANG JI-YOUNG; WU KUANG-YEU; CHUANG KARL TZE-TANG

36

The PVT Properties of Acetic Acid.  

Science.gov (United States)

The PVT properties of acetic acid in the saturated and single-phase regions were measured at temperatures between 448.15 and 603.15 K, at pressures up to about 10 MPa. The experimental results were corrected for decomposition of the sample.

D. A. Lee G. B. Lewis I. J. Lawrenson

1977-01-01

37

2-(3-Hydroxybenzylamino)acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available There are two independent 2-(3-hydroxybenzylamino)acetic acid molecules, C9H11NO3, in the asymmetric unit of the title compound. The dihedral angle between the benzene rings of the two independent molecules is 58.12?(4)°. The crystal packing is stablized by intermolecular O—H...O and N—H...O hydrogen bonds.

Li-Hua Zhi; Wei-Na Wu

2011-01-01

38

Removal of nitrate by electrodialysis in the presence of acetate  

International Nuclear Information System (INIS)

In order to remove nitrate selectively from different salt-loaded water, we have studied the electrodialysis of a solution containing nitrate and acetate ions through an original ion exchange membrane. We have showed that NO3- was removed more effectively than CH3COO-. We realized electrodialysis of synthetic solutions containing first of all a single kind of anion, the ion nitrate or the ion acetate, and in the second place the mixture of both kinds of ions and at the same concentration. The ion-exchange membrane (MEA) was obtained from the company ERAS Labo [1], designed initially for use in alkaline fuel cells. We wanted to test its behavior for electrodialysis. The results show that this MEA behaves practically in the same way towards both kinds of ions when the solution contains only a single kind of anion, the migration rate being linked to the value of the current. But once the anions are mixed, we noticed that the migration of the ion nitrate of the central compartment into the anodic compartment was much faster than that of the ion acetate. NO3-migrating easily while the CH3COO- stops practically migrating during 10 min approximately of time of electrodialysis. This demonstrates a selectivity of this kind of membrane towards the anion nitrate. The ion mobility, the hydrated ionic radii as well as the conductivity of the ionic solution may influence the transfer through the utilized membrane.

2009-01-01

39

Study of manganese and cadmium acetates solvation in hexane-acetic acid solutions by slubility method  

Energy Technology Data Exchange (ETDEWEB)

Solubility of manganese (2) and cadmium (2) acetates in binary solvent acetic acid-hexane is measured at 298.15 K. Depending on the acetic acid concentration (c/sub HAc/) solubility value (S) of cadmium salt is determined by the equation: lgS/sub CdAc(sub 2)/=-5.50+2.91 c/sub HAc/(c/sub HAc/=0.55-1 mole parts). Cadmium acetate during dissolving binds on the average 5.6 acetic acid molecules.

Golubchikov, O.A.; Kadykov, V.V.; Kuvshinova, E.M.; Berezin, B.D.

1986-01-01

40

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 aqu...

Bhupesh C. Roy; M.J. Kabir; M.S. Rahman

 
 
 
 
41

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

42

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

43

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

44

Process for the Production of Acetic Acid  

UK PubMed Central (United Kingdom)

A process produces acetic acid by continuously carrying out a reaction of methanol with carbon monoxide in the presence of a Group VIII metal catalyst, an iodide salt, methyl iodide, and water in a reactor, continuously withdrawing a reaction mixture from the reactor, introducing the reaction mixture into an evaporation process at a pressure lower than that in the reaction to separate the reaction mixture into low-boiling components and high-boiling components containing the Group VIII metal and the iodide salt, and recycling the separated high-boiling components containing the Group VIII metal and the iodide salt to the reactor, in which the separated high-boiling components are brought into contact with hydrogen at temperatures of 80 DEG C.; or higher for 6 seconds or longer before the high-boiling components reaching the reactor, which hydrogen is introduced in an amount of 0.1 time by mole or more that of the Group VIII metal. According to the process, industrially, acetic acid is efficiently produced with high productivity, because the activity of a catalyst in a reactor may be increased without increasing a hydrogen partial pressure in the reactor more than necessary, and a shift reaction may be suppressed to thereby reduce by-products.

KOJIMA HIDETAKA

45

Rapid Economic, Acetic Acid, Papanicolaou Stain (REAP) -  

Directory of Open Access Journals (Sweden)

Full Text Available The universal stain for cervical cytological screening is Papanicolaou stain which has been used in different laboratories with many modifications. Aims: The study is designed to search for a superior and improved qualitative staining technique which is cheaper but rapid in cancer screening by cytology. The modified technique is referred as Rapid, economic, acetic acid Papanicolaou stain (REAP).Material & methods: 220 PAP smears from 110 patients ( 2 per subject) were collected . One set of smears was stained by conventional Papanicolaou stain & the other set by REAP stain. Pre- Orange G 6 & post- Orange G 6 and post- EA50 ethanol baths in REAP stain were replaced by 1% acetic acid. Tap water was used instead of Scott’s tap water to reduce cost. Hematoxylin was preheated in waterbath to 60? C before staining for rapid penetration. Methanol was used for final dehydration. Results: The two methods were compared in respect of optimal cytoplasmic & nuclear staining, stain preservation, cost & total time for the procedure. In REAP technique, cytoplasmic & nuclear staining was optimal in 100 & 105 cases respectively. The cost was reduced to 25% due to limited alcohol use. The staining-time was minimised to 3 minutes. Conclusion: REAP stain, in comparison to conventional Papanicolaou, provides a suitable, excellent & rapid alternative for cytological screening with minimum cost. The stain preservation is also good in REAP method.

Ranu RoyBiswas

2008-01-01

46

Conformational studies of hydantoin-5-acetic acid and orotic acid.  

Science.gov (United States)

Hydantoin-5-acetic acid [2-(2,5-dioxoimidazolidin-4-yl)acetic acid] and orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid) each contain one rigid acceptor-donor-acceptor hydrogen-bonding site and a flexible side chain, which can adopt different conformations. Since both compounds may be used as coformers for supramolecular complexes, they have been crystallized in order to examine their conformational preferences, giving solvent-free hydantoin-5-acetic acid, C(5)H(6)N(2)O(4), (I), and three crystals containing orotic acid, namely, orotic acid dimethyl sulfoxide monosolvate, C(5)H(4)N(2)O(4)·C(2)H(6)OS, (IIa), dimethylammonium orotate-orotic acid (1/1), C(2)H(8)N(+)·C(5)H(3)N(2)O(4)(-)·C(5)H(4)N(2)O(4), (IIb), and dimethylammonium orotate-orotic acid (3/1), 3C(2)H(8)N(+)·3C(5)H(3)N(2)O(4)(-)·C(5)H(4)N(2)O(4), (IIc). The crystal structure of (I) shows a three-dimensional network, with the acid function located perpendicular to the ring. Interestingly, the hydroxy O atom acts as an acceptor, even though the carbonyl O atom is not involved in any hydrogen bonds. However, in (IIa), (IIb) and (IIc), the acid functions are only slightly twisted out of the ring planes. All H atoms of the acidic functions are directed away from the rings and, with respect to the carbonyl O atoms, they show an antiperiplanar conformation in (I) and synperiplanar conformations in (IIa), (IIb) and (IIc). Furthermore, in (IIa), (IIb) and (IIc), different conformations of the acid O=C-C-N torsion angle are observed, leading to different hydrogen-bonding arrangements depending on their conformation and composition. PMID:22307261

Gerhardt, Valeska; Tutughamiarso, Maya; Bolte, Michael

2012-01-18

47

Conformational studies of hydantoin-5-acetic acid and orotic acid.  

UK PubMed Central (United Kingdom)

Hydantoin-5-acetic acid [2-(2,5-dioxoimidazolidin-4-yl)acetic acid] and orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid) each contain one rigid acceptor-donor-acceptor hydrogen-bonding site and a flexible side chain, which can adopt different conformations. Since both compounds may be used as coformers for supramolecular complexes, they have been crystallized in order to examine their conformational preferences, giving solvent-free hydantoin-5-acetic acid, C(5)H(6)N(2)O(4), (I), and three crystals containing orotic acid, namely, orotic acid dimethyl sulfoxide monosolvate, C(5)H(4)N(2)O(4)·C(2)H(6)OS, (IIa), dimethylammonium orotate-orotic acid (1/1), C(2)H(8)N(+)·C(5)H(3)N(2)O(4)(-)·C(5)H(4)N(2)O(4), (IIb), and dimethylammonium orotate-orotic acid (3/1), 3C(2)H(8)N(+)·3C(5)H(3)N(2)O(4)(-)·C(5)H(4)N(2)O(4), (IIc). The crystal structure of (I) shows a three-dimensional network, with the acid function located perpendicular to the ring. Interestingly, the hydroxy O atom acts as an acceptor, even though the carbonyl O atom is not involved in any hydrogen bonds. However, in (IIa), (IIb) and (IIc), the acid functions are only slightly twisted out of the ring planes. All H atoms of the acidic functions are directed away from the rings and, with respect to the carbonyl O atoms, they show an antiperiplanar conformation in (I) and synperiplanar conformations in (IIa), (IIb) and (IIc). Furthermore, in (IIa), (IIb) and (IIc), different conformations of the acid O=C-C-N torsion angle are observed, leading to different hydrogen-bonding arrangements depending on their conformation and composition.

Gerhardt V; Tutughamiarso M; Bolte M

2012-02-01

48

Tested Demonstrations: Buffer Capacity of Various Acetic Acid-Sodium Acetate Systems: A Lecture Experiment.  

Science.gov (United States)

Background information and procedures are provided for a lecture experiment which uses indicators to illustrate the concept of differing buffer capacities by titrating acetic acid/sodium acetate buffers with 1.0 molar hydrochloric acid and 1.0 molar sodium hydroxide. A table with data used to plot the titration curve is included. (JN)

Donahue, Craig J.; Panek, Mary G.

1985-01-01

49

ALLYL ACETATE PURIFICATION  

UK PubMed Central (United Kingdom)

A process for purifying allyl acetate is disclosed. An acetoxylation mixture is distilled at elevated pressure to remove propylene and generate a first bottoms mixture comprising allyl acetate, acetic acid, acrolein, allyl diacetate, and 3-acetoxypropionaldehyde. The first bottoms mixture is flash vaporized, and the resulting vapor is contacted with a solid acidic catalyst under conditions effective to decompose allyl diacetate and 3-acetoxypropionaldehyde. The flashed product, which comprises allyl acetate, acetic acid, and acrolein, is then distilled to remove acrolein and generate a second bottoms mixture comprising allyl acetate and acetic acid. The second bottoms mixture can be used to manufacture allyl alcohol.

HARRIS STEPHEN H; LIN SHAW-CHAN

50

Allyl acetate purification  

UK PubMed Central (United Kingdom)

A process for purifying allyl acetate is disclosed. An acetoxylation mixture is distilled at elevated pressure to remove propylene and generate a first bottoms mixture comprising allyl acetate, acetic acid, acrolein, allyl diacetate, and 3-acetoxypropionaldehyde. The first bottoms mixture is flash vaporized, and the resulting vapor is contacted with a solid acidic catalyst under conditions effective to decompose allyl diacetate and 3-acetoxypropionaldehyde. The flashed product, which comprises allyl acetate, acetic acid, and acrolein, is then distilled to remove acrolein and generate a second bottoms mixture comprising allyl acetate and acetic acid. The second bottoms mixture can be used to manufacture allyl alcohol.

HARRIS STEPHEN H; LIN SHAW-CHAN

51

Fluidized bed biomethanation of acetic acid  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of acetate biomethanation was studied in a high recycle ratio biological fluidized bed reactor behaving in practice as a completely mixed reactor. The active biofilm consisted of bacteria from a methane fermenter that after spontaneous immobilization on the bed particles (sand) were adapted to acetate as the only carbon source. The effects of temperature (13/sup 0/, 20/sup 0/, 25/sup 0/ and 35/sup 0/C), substrate concentration (500, 1000 and 1500 mg chemical oxygen demand (COD)1/sup -1/) and hydraulic retention time theta (1 to 8 h) on substrate consumption were studied. Maximum substrate consumption (as % COD reduction) amounted from 25% (13/sup 0/C, 1500 mg COD 1/sup -1/) to 93% (35/sup 0/C, 500 mg COD 1/sup -1/). At 35/sup 0/C the concentration of attached biomass presented a weakly increase with reactor substrate concentration (from 3.10 g VS 1/sup -1/ to 4.54 g VS 1/sup -1/ for 32 and 1150 mg COD 1/sup -1/, respectively). On the other hand when reducing theta, a sharp increase in biomass loss coefficient was observed showing that excess biofilm growth was continuously removed by shearing forces. Thus in the assayed conditions the attached biomass concentration was basically determined by the bed superficial velocity. Results show that diffusional resistances are negligible. Data are fairly well correlated by a variable order kinetic model. The apparent reaction order is a function of temperature and increases from 0.27 to 0.7 when temperature decreases from 35/sup 0/C to 13/sup 0/C.

Toldra, F.; Flors, A.; Lequerica, J.L.; Valles, S.

1986-02-01

52

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-12-15

53

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

54

CARBONYLATION PROCESS FOR THE PRODUCTION OF ACETIC ACID AND/OR METHYL ACETATE  

UK PubMed Central (United Kingdom)

A process for the manufacture of at least one of acetic acid and methyl acetate by the carbonylation of methanol, dimethyl ether and/or dimethyl carbonate with carbon monoxide in the presence of a zeolite catalyst of structure type MOR having a crystal size of no greater than about 3 microns.

CORMA CANOS AVELINO; HAINING GORDON JOHN; LAW DAVID JOHN

55

Predicting total soil lead from an acetic acid-sodium acetate buffered solution  

Energy Technology Data Exchange (ETDEWEB)

Total soil lead was predicted satisfactorily from the lead extracted by the Standard Morgan soil testing solution (sodium acetate with acetic acid, pH 4.8). A modified Morgan solution, utilizing EDTA as a chelating agent, extracted greater than 3 times as much lead as the regular Morgan's solution, but was no better in predicting total lead.

Nicklow, C.W. (Univ. of Massachusetts, Waltham); Norvell, W.A.; Spittler, T.

1981-01-01

56

Simultaneous acetic acid separation and monosaccharide concentration by reverse osmosis.  

UK PubMed Central (United Kingdom)

This study aimed to investigate the feasibility and efficiency of simultaneous acetic acid separation and sugar concentration in model lignocellulosic hydrolyzates by reverse osmosis. The effects of operation parameters such as pH, temperature, pressure and feed concentration on the solute retentions were examined with a synthetic xylose–glucose–acetic acid model solution. Results showed that the monosaccharides were almost completely rejected at above 20 bar, while the acetic acid retention increased with the increase in pH and pressure, and decreased with the temperature increase. The maximum separation factors of acetic acid over xylose and glucose reached as high as 211.5 and 228.4 at pH 2.93 (the initial pH of model lignocellulosic hydrolyzates), 40 °C and 20 bar. Furthermore, the concentration and diafiltration process were employed at optimal operation conditions. Consequently, a high sugar concentration and a beneficially lower acetic acid concentration were simultaneously achieved by reverse osmosis.

Zhou F; Wang C; Wei J

2013-03-01

57

Isolation of cellulose from rice straw and its conversion into cellulose acetate catalyzed by phosphotungstic acid.  

UK PubMed Central (United Kingdom)

Cellulose was isolated from rice straw by pretreatment with dilute alkaline and acid solutions successively, and it was further transferred into cellulose acetate in the presence of acetic anhydride and phosphotungstic acid (H3PW12O40·6H2O). The removal of hemicellulose and lignin was affected by the concentration of KOH and the immersion time in acetic acid solution, and 83wt.% content of cellulose in the treated rice straw was obtained after pretreatment with 4% KOH and immersion in acetic acid for 5h. Phosphotungstic acid was found to be an effective catalyst for the acetylation of the cellulose derived from rice straw. The degree of substitution (DS) values revealed a significant effect for the solubility of cellulose acetate, and the acetone-soluble cellulose acetate with DS values around 2.2 can be obtained by changing the amount of phosphotungstic acid and the time of acetylation. Both the structure of cellulose separated from rice straw and cellulose acetate were confirmed by FTIR and XRD.

Fan G; Wang M; Liao C; Fang T; Li J; Zhou R

2013-04-01

58

Isolation of cellulose from rice straw and its conversion into cellulose acetate catalyzed by phosphotungstic acid.  

Science.gov (United States)

Cellulose was isolated from rice straw by pretreatment with dilute alkaline and acid solutions successively, and it was further transferred into cellulose acetate in the presence of acetic anhydride and phosphotungstic acid (H3PW12O40·6H2O). The removal of hemicellulose and lignin was affected by the concentration of KOH and the immersion time in acetic acid solution, and 83wt.% content of cellulose in the treated rice straw was obtained after pretreatment with 4% KOH and immersion in acetic acid for 5h. Phosphotungstic acid was found to be an effective catalyst for the acetylation of the cellulose derived from rice straw. The degree of substitution (DS) values revealed a significant effect for the solubility of cellulose acetate, and the acetone-soluble cellulose acetate with DS values around 2.2 can be obtained by changing the amount of phosphotungstic acid and the time of acetylation. Both the structure of cellulose separated from rice straw and cellulose acetate were confirmed by FTIR and XRD. PMID:23544511

Fan, Guozhi; Wang, Min; Liao, Chongjing; Fang, Tao; Li, Jianfen; Zhou, Ronghui

2013-02-01

59

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

60

Acetic acid ulcer model - state of the art in 2010  

Directory of Open Access Journals (Sweden)

Full Text Available Two types of a chronic ulcer model, named acetic acid ulcers, have been developed in experimental animals to examine the healing process of gastro-duodenum ulcers, screen ulcer-healing drugs, and evaluate the adverse effects of various anti-inflammatory drugs and/or Helicobacter pylori (H. pylori) infection on the gastrointestinal mucosa. The model demonstrates ease and reliability for producing round, deep ulcers in the stomach and duodenum in mice, rats, Mongolian gerbils, guinea pigs, cats, dogs, miniature pigs, and monkeys. One of the characteristic features of acetic acid ulcers in rats is the spontaneous relapse of healed ulcers >100 days after ulceration, an endoscopical examination confirmed the phenomenon. Indomethacin significantly delays the healing of acetic acid ulcers, probably by reducing endogenous prostaglandins and inhibiting angiogenesis in ulcerated tissue. H. pylori significantly delays healing of acetic acid ulcers and causes relapse of healed ulcers at a high incidence in Mongolian gerbils. Antisecretory drugs (e.g. omeprazole, lansoprazole) and mucosal defensive drugs (e.g. sucralfate, irsogladine maleate, rebamipide) are known to enhance healing of acetic acid ulcers. In addition, we discussed the potential usefulness of acetic acid ulcer models for early gastric tumor therapy by changing a malignant tumor to a benign ulcer by applying acetic acid under the tumor tissue or topically to the luminal surface of tumor tissue using an endoscope.

Susumu Okabe; Kikuko Amagase; Koji Takeuchi

2010-01-01

 
 
 
 
61

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

1999-01-01

62

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

63

The antibacterial activity and stability of acetic acid.  

UK PubMed Central (United Kingdom)

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.

Fraise AP; Wilkinson MA; Bradley CR; Oppenheim B; Moiemen N

2013-08-01

64

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

International Nuclear Information System (INIS)

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

1993-01-01

65

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; E. A. Campanella

2006-01-01

66

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

67

Biosynthesis of Indole-3-Acetic Acid in Higher Plants ??????????????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

CONTENTS / p2 , Chapter1 General Introduction / p1 ,   1.1 Discovery of First Plant Hormone,Indole-3-Acetic Acid / p1 ,   1.2 Research of Indole-3-Acetic Acid Biosynthesis Pathway in Higher Plants / p2 ,   1.3 Auxin Receptor for Cell Elongation in Higher Plants / p8 ,   1.4 Purpose of This Study / p9 , Chapter2 Biosy...

??, ??; ????, ????; Tsurusaki, Ken'ichi; Tsurusaki, Ken-ichi

68

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

2013-01-01

69

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; M.J. Kabir; M.S. Rahman

2005-01-01

70

Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.  

Science.gov (United States)

Acetic acid bacteria (AAB) are Gram-negative, strictly aerobic microorganisms that show a unique resistance to ethanol (EtOH) and acetic acid (AcH). Members of the Acetobacter and Gluconacetobacter genera are capable of transforming EtOH into AcH via the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes and are used for the industrial production of vinegar. Several mechanisms have been proposed to explain how AAB resist high concentrations of AcH, such as the assimilation of acetate through the tricarboxylic acid (TCA) cycle, the export of acetate by various transporters and modifications of the outer membrane. However, except for a few acetate-specific proteins, little is known about the global proteome responses to AcH. In this study, we used 2D-DIGE to compare the proteome of Acetobacter pasteurianus LMG 1262(T) when growing in glucose or ethanol and in the presence of acetic acid. Interesting protein spots were selected using the ANOVA p-value of 0.05 as threshold and 1.5-fold as the minimal level of differential expression, and a total of 53 proteins were successfully identified. Additionally, the size of AAB was reduced by approximately 30% in length as a consequence of the acidity. A modification in the membrane polysaccharides was also revealed by PATAg specific staining. PMID:22155126

Andrés-Barrao, Cristina; Saad, Maged M; Chappuis, Marie-Louise; Boffa, Mauro; Perret, Xavier; Ortega Pérez, Ruben; Barja, François

2011-12-02

71

Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.  

UK PubMed Central (United Kingdom)

Acetic acid bacteria (AAB) are Gram-negative, strictly aerobic microorganisms that show a unique resistance to ethanol (EtOH) and acetic acid (AcH). Members of the Acetobacter and Gluconacetobacter genera are capable of transforming EtOH into AcH via the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes and are used for the industrial production of vinegar. Several mechanisms have been proposed to explain how AAB resist high concentrations of AcH, such as the assimilation of acetate through the tricarboxylic acid (TCA) cycle, the export of acetate by various transporters and modifications of the outer membrane. However, except for a few acetate-specific proteins, little is known about the global proteome responses to AcH. In this study, we used 2D-DIGE to compare the proteome of Acetobacter pasteurianus LMG 1262(T) when growing in glucose or ethanol and in the presence of acetic acid. Interesting protein spots were selected using the ANOVA p-value of 0.05 as threshold and 1.5-fold as the minimal level of differential expression, and a total of 53 proteins were successfully identified. Additionally, the size of AAB was reduced by approximately 30% in length as a consequence of the acidity. A modification in the membrane polysaccharides was also revealed by PATAg specific staining.

Andrés-Barrao C; Saad MM; Chappuis ML; Boffa M; Perret X; Ortega Pérez R; Barja F

2012-03-01

72

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.

Santosh Kumar Singh; Narendra Manne; Purna Chandra Ray; Manojit Pal

2008-01-01

73

Liquid-liquid equilibria of the ternary systems water + acetic acid + ethyl acetate and water + acetic acid + isophorene (3,5,5-trimethyl-2-cyclohexen-1-one)  

Energy Technology Data Exchange (ETDEWEB)

Liquid-liquid equilibria for the ternary systems water + acetic acid + ethyl acetate and water + acetic acid + isophorone (3,5,5-trimethyl-2-cyclohexen-1-one) were measured over the temperature range (283 to 313) K. The results were used to estimate the interaction parameters between each of the three compounds of the systems studied for the NRTL and UNIQUAC models. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the two models; experimental data were successfully reproduced. The UNIQUAC model was the most accurate in correlating the overall equilibrium composition of the studied systems. Also the NRTL model satisfactorily predicted the equilibrium composition. Isophorone experimentally resulted in a better extraction capacity for acetic acid and in a lower miscibility with water.

Colombo, A.; Battilana, P.; Ragaini, V.; Bianchi, C.L. [Milan Univ. (Italy). Dept. of Physical Chemistry and Electrochemistry; Carvoli, G. [Chemial S.p.A., Cavaglia (Italy)

1999-01-01

74

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  

Energy Technology Data Exchange (ETDEWEB)

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-d2 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 25C and the activation parameters are k = (5.5 +/- 0.2) x 10V s , H = 41 +/- 2 kJ mol , and S = 3 +/- 7 J mol K for NiCl2, k = (3 +/- 1) x 10V s , H = 37 +/- 5 kJ mol , and element of = -18 +/- 20 J mol K for Ni(NO3)2, and k = (3 +/- 1) x 10V s , H = 50 +/- 5 kJ mol , and S = 28 +/- 20 J mol K for Ni(OAc)2. Solvent exchange was proposed to proceed via a dissociative-interchange mechanisms. 34 references, 5 figures, 1 table

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

1985-11-07

75

Process for acid gas removal.  

UK PubMed Central (United Kingdom)

A process for the removal of acid gases from mixtures by contacting the said mixtures in an absorber (10) with a solvent which comprises a chemical absorbent, 5-55%w water, and, if desired, a physical absorbent, regenerating the loaded solvent (18) thus obtained by steam stripping in a regenerator (20), withdrawing the resulting water vapour (34) and desorbed gases from the regenerator (20) condensing the water vapour to yield a condensate, and recycling the regenerated solvent (16) to the absorber (10) afterat least part of the condensate (4 ) has been added back thereto.

VAN DE KRAATS EDUARD JOHAN; DARTON RICHARD CHARLES

76

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

UK PubMed Central (United Kingdom)

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.

Gullo M; Caggia C; De Vero L; Giudici P

2006-02-01

77

Manufacturing method of acetic acid; Sakusan no seizoho  

Energy Technology Data Exchange (ETDEWEB)

The acetic acid is made to be the organic chemistry base product, and a demand of the world has exceeded the 5.5 million tons/year. Or, the application is widely utilized as chemicals raw material such as vinyl acetate, solvent, and acetyl cellulose as reaction solvent and reagent. It has gone over to the field of diversity such as food, medicine, dye, coating material, fiber, plastic, and photograph in the last application tip. In the inside, it is used as a reaction solvent for the terephthalic acid manufacturing of polyester raw material. (NEDO)

Sato, E. [Showa Denko Corp., Tokyo (Japan)

1999-11-01

78

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

79

T09PAA101 Acetic Acid Glacial  

Science.gov (United States)

Text Version... 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) (hereinafter referred to as “PAA solutions”) as an antimicrobial to treat poultry carcasses, to ... More results from www.fda.gov/downloads/food/ingredientspackaginglabeling

80

Integrated process for making acetic acid and methanol from natural gas  

UK PubMed Central (United Kingdom)

An integrated process for making methanol, acetic acid, and a product from an associated process is disclosed. Syngas (120) is produced by combined steam reforming (109) and autothermal reforming (118) of natural gas (102) where a portion (112) of the natural gas bypasses the steam reformer (109) and is blended with the steam reformer effluent for supply to the autothermal reformer (ATR) (118) with CO2 recycle (110). A portion of the syngas is fed to CO2 removal (122) to obtain the recycle CO2 and cold box (130) to obtain a hydrogen stream (131) and a CO stream (135). The remaining syngas, hydrogen stream (131) and CO2 from an associated process are fed to methanol synthesis (140), which produces methanol and a purge stream (124) supplied to the CO2 removal unit. The methanol is supplied to an acetic acid unit (136) with the CO (135) to make acetic acid, which in turn is supplied to a vinyl acetate monomer (VAM) synthesis unit (148). Oxygen for both the ATR and VAM synthesis can be supplied by a common air separation unit (116), and utilities such as steam generation can further integrate the process.

THIEBAUT DANIEL MARCEL

 
 
 
 
81

Vapor-liquid equilibrium for the binary systems ethyl acetate-acetic acid and ethyl propionate-propionic acid  

Energy Technology Data Exchange (ETDEWEB)

Vapor-liquid equilibrium (VLE) data have been measured for mixtures of ethyl acetate with acetic acid at 338 and 346 K and for mixtures of ethyl propionate with propionic acid at 358 and 368 K. The measurements were carried out in a recirculation still similar to that of Dvorak and Boublik. The data have been consistency tested by means of a maximum-likelihood procedure providing at the same time the relevant UNIQUAC parameters. Vapor pressures of the pure substances have been measured, and the data have been correlated with the Antoine equation.

Macedo, E.A.; Rasmussen, P.

1982-10-01

82

Methanol plant retrofit for manufacture of acetic acid  

UK PubMed Central (United Kingdom)

The retrofitting of an existing methanol or methanol/ammonia plant to make acetic acid is disclosed. The existing plant has a reformer (10) to which natural gas or another hydrocarbon and steam (water) are fed. Syngas is formed in the reformer (10). All or part of the syngas is processed to separate out carbon dioxide (24), carbon monoxide (30) and hydrogen (32), and the separated carbon dioxide (24) is fed either to the existing methanol synthesis loop (12) for methanol synthesis, or back into the feed to the reformer (10) to enhance carbon monoxide formation in the syngas (18). Any remaining syngas (38) not fed to the carbon dioxide separator (22) can be converted to methanol in the existing methanol synthesis loop (12) along with carbon dioxide (24) from the separator (22) and/or imported carbon dioxide (25), and hydrogen (35) from the separator (28). The separated carbon monoxide (30) is then reacted with the methanol (36) to produce acetic acid (40) or an acetic acid precursor by a conventional process. Also disclosed is the reaction of separated hydrogen (32) with nitrogen (52), in a conventional manner, to produce ammonia. Also disclosed is the reaction of a portion of the acetic acid (40) in a conventional manner with oxygen (46) and ethylene (44) to form vinyl acetate monomer (48). The nitrogen for the added ammonia capacity in a retrofit of an original methanol plant comprising an ammonia synthesis loop (33), and the oxygen (46) for the vinyl acetate monomer process (42), are obtained from a new air separation unit (50).

VIDALIN KENNETH EBENNES; THIEBAUT DANIEL MARCEL

83

Recovery of gossypol acetic acid from cottonseed soapstock.  

UK PubMed Central (United Kingdom)

Gossypol is a yellow pigment found in the cotton plant and is of scientific and medical interest because of its anti-tumor, anti-fertility, and anti-viral properties. In order to support additional studies into the medicinal activity of gossypol, methods are needed to isolate large quantities of the compound in high purity. A process is described to recover gossypol from cottonseed soapstock, a low-value co-product of crude oil refining that can contain concentrations of gossypol as high as 8 percent. Soapstock is refluxed in acidic methyl ethyl ketone (MEK) to hydrolyze covalently bound gossypol. Upon cooling, the mixture separates into organic and aqueous phases with the gossypol distributing between the two phases. The MEK phase is recovered, and the aqueous phase is re-extracted with additional volumes of MEK. After combining and concentrating the MEK extracts, acetic acid is added to induce gossypol crystallization, which precipitates as an equimolar crystalline complex with acetic acid (gossypol acetic acid). From a soapstock sample containing 3.7% gossypol, 63% of the gossypol was recovered as an 87% gossypol acetic acid product. A single re-crystallization of this crude material yielded a 99% gossypol acetic acid product with an overall recovery of 58%. With different soapstock samples, the yield of crude product was positively correlated with the initial gossypol concentration in the soapstock. Recovery, however, was not well correlated with soapstock gossypol concentration, possibly due to the co-extraction of other components that influence the solubility of gossypol in the crystallization solution.

Dowd MK; Pelitire SM

2001-09-01

84

KRAFT MILL BIOREFINERY TO PRODUCE ACETIC ACID AND ETHANOL: TECHNICAL ECONOMIC ANALYSIS  

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Full Text Available The “near neutral hemicellulose extraction process” involves extraction of hemicellulose using green liquor prior to kraft pulping. Ancillary unit operations include hydrolysis of the extracted carbohydrates using sulfuric acid, removal of extracted lignin, liquid-liquid extraction of acetic acid, liming followed by separation of gypsum, fermentation of C5 and C6 sugars, and upgrading the acetic acid and ethanol products by distillation. The process described here is a variant of the “near neutral hemicellulose extraction process” that uses the minimal amount of green liquor to maximize sugar production while still maintaining the strength quality of the final kraft pulp. Production rates vary between 2.4 to 6.6 million gallons per year of acetic acid and 1.0 and 5.6 million gallons per year of ethanol, depending upon the pulp production rate. The discounted cash flow rate of return for the process is a strong function of plant size, and the capital investment depends on the complexity of the process. For a 1,000 ton per day pulp mill, the production cost for ethanol was estimated to vary between $1.63 and $2.07/gallon, and for acetic acid between $1.98 and $2.75 per gallon depending upon the capital equipment requirements for the new process. To make the process economically attractive, for smaller mill sizes the processing must be simplified to facilitate reductions in capital cost.

Haibo Mao; Joseph M. Genco; Adriaan van Heiningen; Hemant Pendse

2010-01-01

85

Acetic acid ulcer model - state of the art in 2010  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two types of a chronic ulcer model, named acetic acid ulcers, have been developed in experimental animals to examine the healing process of gastro-duodenum ulcers, screen ulcer-healing drugs, and evaluate the adverse effects of various anti-inflammatory drugs and/or Helicobacter pylori (H. pylori) i...

Susumu Okabe; Kikuko Amagase; Koji Takeuchi

86

Kinetics of acetic acid oxidation in supercritical water  

Energy Technology Data Exchange (ETDEWEB)

Acetic acid was oxidized in supercritical water in batch microreactors at temperatures between 380 and 440[degrees]C. The acetic acid concentrations ranged from 1.0 [times] 10[sup [minus]4] to 5.2 [times] 10[sup [minus]3] M, the oxygen concentrations ranged from 5.7 [times] 10[sup [minus]3] to 7.1 [times] 10[sup [minus]2] M, and the water density ranged from 6.7 to 25 M. Oxygen was always present in at least 3.5 times the stoichiometric amount required for complete oxidation. Analysis of the kinetics data showed that the global oxidation rate law was first order in acetic acid, 0.6 order in oxygen, and second order in water. The global rate constant has a pre-exponential factor of 10[sup 19.8] M[sup [minus]26] S[sup [minus]1] and an activation energy of 73.6 kcal/mol. This rate law also satisfactorily describes other sets of experimental data in the literature for the oxidation of acetic acid in supercritical water. 19 refs., 5 figs., 3 tabs.

Savage, P.E.; Smith, M.A. (Univ. of Michigan, Ann Arbor, MI (United States))

1995-01-01

87

Corrosion resistance of zirconium alloys in acetic acid environment  

International Nuclear Information System (INIS)

Studies on corrosion resistance of E100 (1%Nb) and E125(2.5%Nb) zirconium alloys and their welded joints in acetic acid media are carried out. The study results show that zirconium alloys are characterized by sufficiently good corrosion resistance. Insignificant corrosion of general character is identified in welded joints. 1 ref.

1995-01-01

88

First Acetic Acid Survey with CARMA in Hot Molecular Cores  

CERN Multimedia

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

89

Radiolysis of adsorbed acetic acid on Na-montmorillonite  

International Nuclear Information System (INIS)

In this work, the authors investigate the influence of doses and water content on the radiolysis of acetic acid adsorbed in a clay surface (Na-montmorillonite). The reaction was followed by the formation of CO2, also for other non-volatile radiolytic products from 14C-acetic acid. The main reaction observed was a decarboxylation reaction. The mechanism of this heterogeneous catalysis is complex. This reaction can be promoted by a loss of electrons from the carbonyl group of the acid and could be accepted by acid sites on clay. Other mechanisms that are currently under study involve energy transfer process and free radical initiator by the water radiolytic products trapped in the clay lattice.

1991-01-01

90

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 tet...

Santosh Kumar Singh; Narendra Manne; Purna Chandra Ray; Manojit Pal

91

High resolution acetic acid survey and water vapor radiometer  

Science.gov (United States)

Planets, comets, stars, galaxies and the interstellar medium (ISM) emit complex but distinct molecular spectra. These spectra reveal the chemical composition and physical conditions in the objects. For example, many biologically important molecules, such as acetic acid, formic acid, vinyl cyanide and ethyl cyanide, have been detected in hot molecular cores in the ISM. A diversity of molecules creates complicated and yet interesting astrochemistry in hot cores. However, the formation mechanisms of large molecules are still unclear. Hence large molecule observations are essential to understand hot core chemistry. Among these molecules, acetic acid is one of the most important large species in hot cores. It is a possible precursor of glycine, the simplest amino acid. It only has been detected in high-mass hot cores without oxygen/nitrogen chemical differentiation, which is key to hot core chemical models. Using the Combined Array for Research in Millimeter-wave Astronomy (CARMA), we have conducted an acetic acid survey in hot cores. In our survey, we have discovered a new acetic acid hot core, G19.61-0.23, which also shows no chemical differentiation. Therefore, we suggest that both large oxygen and nitrogen- bearing species play important roles in acetic acid formation. Ground-based interferometric observations are severely affected by atmospheric conditions. Phase correction is a technique to obtain high quality data and achieve great scientific goals. For our acetic acid survey, a better phase correction technique can not only detect weaker transitions of large molecules, but also increase the map resolution of hot cores. Water vapor radiometers (WVRs) are designed to improve the technique by observing tropospheric water vapor along the lines of sight of interferometers. We have numerically demonstrated the importance of phase correction for interferometric observations and examined the water vapor phase correction technique. Furthermore, we have built two WVR prototypes with new calibration, thermal regulation and backend systems. The WVR prototypes had been tested in a laboratory, on a roof and at the CARMA site to verify their performance. We conclude the WVR thermal stability and dynamic range are critical while the enormous and rapid fluctuations of the sky background emission overwhelm the WVR dynamic range and degrade the WVR sensitivity.

Shiao, Yu-Shao

2008-08-01

92

Lipase-catalyzed synthesis of geranyl acetate in n-hexane with membrane-mediated water removal.  

UK PubMed Central (United Kingdom)

The esterification of geraniol with acetic acid in n-hexane was investigated. A commercial lipase preparation from Candida antarctica was used as catalyst. The equilibrium conversion (no water removal) was found to be 94% for the reaction of 0.1 M alcohol and 0.1 M acid in n-hexane at 30 degrees C. This was shown by both hydrolysis and esterification reactions. The activation energy of reaction over the temperature range 10 degrees to 50 degrees C was found to be 16 kJ/mol. The standard heat of reaction was -28 kJ/mol. Membrane pervaporation using a cellulose acetate/ceramic composite membrane was then employed for selective removal of water from the reaction mixture. The membrane was highly effective at removing water while retaining all reaction components. Negligible transport of the solvent n-hexane was observed. Water removal by pervaporation increased the reaction rate by approximately 150% and increased steady-state conversion to 100%.

Bartling K; Thompson JU; Pfromm PH; Czermak P; Rezac ME

2001-12-01

93

Lipase-catalyzed synthesis of geranyl acetate in n-hexane with membrane-mediated water removal.  

Science.gov (United States)

The esterification of geraniol with acetic acid in n-hexane was investigated. A commercial lipase preparation from Candida antarctica was used as catalyst. The equilibrium conversion (no water removal) was found to be 94% for the reaction of 0.1 M alcohol and 0.1 M acid in n-hexane at 30 degrees C. This was shown by both hydrolysis and esterification reactions. The activation energy of reaction over the temperature range 10 degrees to 50 degrees C was found to be 16 kJ/mol. The standard heat of reaction was -28 kJ/mol. Membrane pervaporation using a cellulose acetate/ceramic composite membrane was then employed for selective removal of water from the reaction mixture. The membrane was highly effective at removing water while retaining all reaction components. Negligible transport of the solvent n-hexane was observed. Water removal by pervaporation increased the reaction rate by approximately 150% and increased steady-state conversion to 100%. PMID:11745145

Bartling, K; Thompson, J U; Pfromm, P H; Czermak, P; Rezac, M E

2001-12-20

94

Kinetic stability of the dysprosium(3) complex with tetraazaporphine in acetic acid-water and acetic acid-methanol mixtures  

International Nuclear Information System (INIS)

Water-soluble dysprosium tetraazaporphine with acetylacetonate-ion as extraligand is synthesized for the first time. Its kinetic stability in acetic acid solutions is investigated. It is shown that the complex is dissociated with formation of free tetraazaporphine. Kinetic parameters of dissociation reaction are determined

1999-01-01

95

[Conversion of acetic acid to methane by thermophiles  

Energy Technology Data Exchange (ETDEWEB)

The primary goal of this project is to obtain a better understanding of thermophilic microorganisms which convert acetic acid to CH[sub 4]. The previous funding period represents a departure from earlier research in this laboratory, which was more physiological and ecological. The present work is centered on the biochemistry of the thermophile Methanothrix sp. strain CALS-1. this organism presents a unique opportunity, with its purity and relatively rapid growth, to do comparative biochemical studies with the other major acetotrophic genus Methanosarcina. We previously found that Methanothrix is capable of using acetate at concentrations 100 fold lower than Methanosarcina. This finding suggests that there are significant differences in the pathways of methanogenesis from acetate in the two genera.

Zinder, S.H.

1993-01-01

96

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

97

The heat of dimerization of acetic acid and the heat of decomposition of ammonium acetate as determined by FTIR spectroscopy  

Science.gov (United States)

Using FTIR spectroscopy - (60.3±2.5) kJ·mol -1 has been obtained for the heat of dimerization of gaseous acetic acid and (110±4) kJ·mol -1 has been obtained for the heat of decomposition of solid ammonium acetate into the gases ammonia and acetic acid monomer. The former value agrees well with previous studies where errors due to wall adsorptions were avoided. The value for the decomposition of ammonium acetate is the first to be directly determined by experiment.

Jaffe, Daniel A.; Rose, Norman J.

98

(Conversion of acetic acid to methane by thermophiles: Progress report)  

Energy Technology Data Exchange (ETDEWEB)

The objective of this project is to provide an understanding of thermophilic anaerobic microorganisms capable of breaking down acetic acid, the precursor of two-thirds of the methane produced by anaerobic bioreactors. Recent results include: (1) the isolation of Methanothrix strain CALLS-1, which grows much more rapidly than mesophilic strains; (2) the demonstration that thermophilic cultures of Methanosarcina and Methanothrix show minimum thresholds for acetate utilization of 1--2.5 mM and 10--20{mu}m respectively, in agreement with ecological data indicating that Methanothrix is favored by low acetate concentration; (3) the demonstration of high levels of thermostable acetyl-coA synthetase and carbon monoxide dehydrogenase in cell-free extracts of Methanothrix strains CALS-1; (4) the demonstration of methanogenesis from acetate and ATP in cell free extracts of strain CALS-1. (5) the demonstration that methanogenesis from acetate required 2 ATP/methane, and, in contrast to Methanosarcina, was independent of hydrogen and other electron donors; (6) the finding that entropy effects must be considered when predicting the level of hydrogen in thermophilic syntrophic cultures. (7) the isolation and characterization of the Desulfotomaculum thermoacetoxidans. Current research is centered on factors which allow thermophilic Methanothrix to compete with Methanosarcina.

Zinder, S.

1991-01-01

99

[Conversion of acetic acid to methane by thermophiles: Progress report  

Energy Technology Data Exchange (ETDEWEB)

The objective of this project is to provide an understanding of thermophilic anaerobic microorganisms capable of breaking down acetic acid, the precursor of two-thirds of the methane produced by anaerobic bioreactors. Recent results include: (1) the isolation of Methanothrix strain CALLS-1, which grows much more rapidly than mesophilic strains; (2) the demonstration that thermophilic cultures of Methanosarcina and Methanothrix show minimum thresholds for acetate utilization of 1--2.5 mM and 10--20{mu}m respectively, in agreement with ecological data indicating that Methanothrix is favored by low acetate concentration; (3) the demonstration of high levels of thermostable acetyl-coA synthetase and carbon monoxide dehydrogenase in cell-free extracts of Methanothrix strains CALS-1; (4) the demonstration of methanogenesis from acetate and ATP in cell free extracts of strain CALS-1. (5) the demonstration that methanogenesis from acetate required 2 ATP/methane, and, in contrast to Methanosarcina, was independent of hydrogen and other electron donors; (6) the finding that entropy effects must be considered when predicting the level of hydrogen in thermophilic syntrophic cultures. (7) the isolation and characterization of the Desulfotomaculum thermoacetoxidans. Current research is centered on factors which allow thermophilic Methanothrix to compete with Methanosarcina.

Zinder, S.

1991-12-31

100

Liquid-Liquid equilibria of the water-acetic acid-butyl acetate system  

Directory of Open Access Journals (Sweden)

Full Text Available Experimental liquid-liquid equilibria of the water-acetic acid-butyl acetate system were studied at temperatures of 298.15± 0.20, 303.15± 0.20 and 308.15± 0.20 K. Complete phase diagrams were obtained by determining solubility and tie-line data. The reliability of the experimental tie-line data was ascertained by using the Othmer and Tobias correlation. The UNIFAC group contribution method was used to predict the observed ternary liquid-liquid equilibrium (LLE) data. It was found that UNIFAC group interaction parameters used for LLE did not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region.

Ince E.; Kirbaslar S. Ismail

2002-01-01

 
 
 
 
101

Liquid-Liquid equilibria of the water-acetic acid-butyl acetate system  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Experimental liquid-liquid equilibria of the water-acetic acid-butyl acetate system were studied at temperatures of 298.15± 0.20, 303.15± 0.20 and 308.15± 0.20 K. Complete phase diagrams were obtained by determining solubility and tie-line data. The reliability of the experimental tie-line data was ascertained by using the Othmer and Tobias correlation. The UNIFAC group contribution method was used to predict the observed ternary liquid-liquid equilibrium (LLE) data. I (more) t was found that UNIFAC group interaction parameters used for LLE did not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region.

Ince, E.; Kirbaslar, S. Ismail

2002-04-01

102

Acetic acid formation via the hydration of gas-phase ketene under ambient conditions  

Science.gov (United States)

We have monitored changes in the infrared spectrum of gas-phase ketene in the presence of water vapor at 295 K. The products observed from ketene hydration are acetic acid, acetic acid dimer, and acetic anhydride. The time-dependence of product formation supports a reaction mechanism in which ketene hydrates to form acetic acid, which then combines with another acetic acid monomer to form a dimer, or with ketene to form acetic anhydride. These results show that ketene can undergo hydration under atmospherically-relevant temperatures and relative humidities. This reaction could be a source of atmospheric carboxylic acids, especially in biomass burning plumes.

Kahan, Tara F.; Ormond, Thomas K.; Ellison, G. Barney; Vaida, Veronica

2013-04-01

103

Acetic acid treatment of pseudomonal wound infections - A review.  

UK PubMed Central (United Kingdom)

PURPOSE: Pseudomonas aeruginosa is a significant cause of burn wound infections and, skin and soft tissue infections. The antiseptic management is an integral part of the management of wound infections and is essential to control wound infection. Although commonly used, concerns have been raised. RESULTS: Available experimental data suggest that many commonly used antiseptic agents may be toxic to the cells involved in wound healing process and may affect the process of normal tissue repair. In view of this, the present review summarized the various organic acids commonly used as a substitute for antiseptics to control pseudomonal wound infections with special reference to acetic acid and their role in the process of wound healing. CONCLUSION: Acetic acid is to be kept in mind as one of the alternatives when infection is caused by multiple antibiotic resistant strains of P. aeruginosa. At a time when bacterial resistance to antibiotics is a matter of increasing concern, the value of topical agents such as acetic acid should not be forgotten.

Nagoba BS; Selkar SP; Wadher BJ; Gandhi RC

2013-07-01

104

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

SM Sharafi; I Rasooli; K Beheshti-Maal

105

Photoaffinity labeling of indole-3-acetic acid-binding proteins in maize  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The photoaffinity labeling agent 5-azidoindole-3-acetic acid, an analog of the endogenous plant hormone indole-3-acetic acid (an auxin), was used to identify indole-3-acetic acid-binding proteins in maize. Two peptides with subunit molecular masses of 24 and 22 kilodaltons are specifically labeled i...

Jones, Alan M.; Venis, Michael A.

106

Electrochemistry of caffeic acid in acetate-ethanolic solutions  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The electrochemical behaviour of caffeic acid in acetate solutions with and without added ethanol was studied by cyclic voltammetry. Solutions of pH and ethanol content close to the wine values (3.5 and 12%, respectively) were studied as a first model approach, pursuing work previously done. Studies at pH 7.4 and different ionic strengths were also done. It was found that cyclic voltammograms of caffeic acid acetate ethanolic solutions had oxidation peak potential values (more) (? 470 mV) at pH 3.5 irrespective of the previous excursions of potential with the same set of electrodes. However, the cathodic peaks potentials and currents strongly depended on the cyclic voltammogram of the corresponding solvent electrolyte which had previously been run. The separation of oxidation and reduction peak potentials evidenced the presence of dimmers of caffeic acid in solution, under the following conditions: 0.1 mol dm-3 acetate buffer pH 3.5 + 12% ethanol with the ionic strength increased by the addition of 0.05 mol dm-3 KCl; limits of the anodic potential: from -100 to + 700 mV and N2 bubbled through the solution for 10 minutes.

Mordido, S.C.; Rebelo, M.J.F.

2006-01-01

107

Electrochemistry of caffeic acid in acetate-ethanolic solutions  

Directory of Open Access Journals (Sweden)

Full Text Available The electrochemical behaviour of caffeic acid in acetate solutions with and without added ethanol was studied by cyclic voltammetry. Solutions of pH and ethanol content close to the wine values (3.5 and 12%, respectively) were studied as a first model approach, pursuing work previously done. Studies at pH 7.4 and different ionic strengths were also done. It was found that cyclic voltammograms of caffeic acid acetate ethanolic solutions had oxidation peak potential values (? 470 mV) at pH 3.5 irrespective of the previous excursions of potential with the same set of electrodes. However, the cathodic peaks potentials and currents strongly depended on the cyclic voltammogram of the corresponding solvent electrolyte which had previously been run. The separation of oxidation and reduction peak potentials evidenced the presence of dimmers of caffeic acid in solution, under the following conditions: 0.1 mol dm-3 acetate buffer pH 3.5 + 12% ethanol with the ionic strength increased by the addition of 0.05 mol dm-3 KCl; limits of the anodic potential: from -100 to + 700 mV and N2 bubbled through the solution for 10 minutes.

S.C. Mordido; M.J.F. Rebelo

2006-01-01

108

A solvent extraction approach to recover acetic acid from mixed waste acids produced during semiconductor wafer process.  

UK PubMed Central (United Kingdom)

Recovery of acetic acid (HAc) from the waste etching solution discharged from silicon wafer manufacturing process has been attempted by using solvent extraction process. For this purpose 2-ethylhexyl alcohol (EHA) was used as organic solvent. In the pre-treatment stage >99% silicon and hydrofluoric acid was removed from the solution by precipitation. The synthesized product, Na(2)SiF(6) having 98.2% purity was considered of commercial grade having good market value. The waste solution containing 279 g/L acetic acid, 513 g/L nitric acid, 0.9 g/L hydrofluoric acid and 0.030 g/L silicon was used for solvent extraction study. From the batch test results equilibrium conditions for HAc recovery were optimized and found to be 4 stages of extraction at an organic:aqueous (O:A) ratio of 3, 4 stages of scrubbing and 4 stages of stripping at an O:A ratio of 1. Deionized water (DW) was used as stripping agent to elute HAc from organic phase. In the whole batch process 96.3% acetic acid recovery was achieved. Continuous operations were successfully conducted for 100 h using a mixer-settler to examine the feasibility of the extraction system for its possible commercial application. Finally, a complete process flowsheet with material balance for the separation and recovery of HAc has been proposed.

Shin CH; Kim JY; Kim JY; Kim HS; Lee HS; Mohapatra D; Ahn JW; Ahn JG; Bae W

2009-03-01

109

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 polyes...

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

110

Indole-3-acetic acid metabolism in normal and dwarf micropropagated banana plants (Musa spp. AAA)  

Directory of Open Access Journals (Sweden)

Full Text Available Nanism is one of the most frequent type of mutant in micropropagated banana plants from the Cavendish subgroup. The present study aimed at studying some of the hormone factors involved in this type of mutation. Rhizomes from normal and dwarf plants from the cultivar Grand Naine were incubated for 5 d in the presence of [³H]-L-tryptophan, [³H]-indole-3-acetic acid and gibberellin, to quantify the endogenous levels of indole-3-acetic acid-ester, indole-3-acetic acid-amide, free indole-3-acetic acid, and cytokinins. The endogenous levels of indole-3-acetic acid and its ester- and amide-conjugated forms were measured in normal and dwarf plants incubated for 30 d with gibberellin, indole-3-acetic acid, and L- and D-tryptophan. In normal plants, the use of [³H]-L-tryptophan resulted in higher levels of radioactivity in the retention times corresponding to indole-3-acetic acid, indole-3-acetic acid-aspartate, indole-3-acetic acid-glycine and indole-3-acetic acid-alanine. These values were higher than those observed in dwarf plants. Higher quantities of radioactive indole-3-acetic acid and of amide-forms in dwarf plants occurred in rhizomes treated with [³H]-L-tryptophan and gibberellin simultaneously. The endogenous levels of total cytokinins were the same in both materials, while the levels of indole-3-acetic acid in normal plants were 1.5 times higher than in dwarf plants. Moreover, in these ones application of tryptophan and gibberellin coincided in an increase in the levels of free indole-3-acetic acid in dwarf plants and to a decrease in the levels of indole-3-acetic acid-ester and indole-3-acetic acid-amide.

Zaffari Gilmar Roberto; Peres Lázaro Eustáquio Pereira; Tcacenco Fernando Adami; Kerbauy Gilberto Barbante

2002-01-01

111

[Effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca].  

Science.gov (United States)

To get the tolerability and consumption of Klebsiella oxytoca on major inhibitors in lignocelluloses hydrolysate, we studied the effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca. The metabolites of furfural and 5-hydroxymethylfurfural were measured. The results show that when acetic acid, furfural and 5-hydroxymethylfurfural was individually added, tolerance threshold for Klebsiella oxytoca was 30 g/L, 4 g/L and 5 g/L, respectively. Acetic acid was likely used as substrate to produce 2,3-butanediol. The yield of 2,3-butanediol increased when acetic acid concentration was lower than 30 g/L. In the fermentation, more than 70% 5-hydroxymethylfurfural was converted to 2,5-furandimethanol. All furfural and the rest of 5-hydroxymethylfurfural were metabolized by Klebsiella oxytoca. It showed that in the detoxification process of 2,3-butanediol production using lignocelluloses hydrolysate, furfural should be given priority to remove and a certain concentration of acetic acid is not need to removal. PMID:23789276

Wu, Jing; Cheng, Keke; Li, Wenying; Feng, Jie; Zhang, Jian'an

2013-03-01

112

[Effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca].  

UK PubMed Central (United Kingdom)

To get the tolerability and consumption of Klebsiella oxytoca on major inhibitors in lignocelluloses hydrolysate, we studied the effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca. The metabolites of furfural and 5-hydroxymethylfurfural were measured. The results show that when acetic acid, furfural and 5-hydroxymethylfurfural was individually added, tolerance threshold for Klebsiella oxytoca was 30 g/L, 4 g/L and 5 g/L, respectively. Acetic acid was likely used as substrate to produce 2,3-butanediol. The yield of 2,3-butanediol increased when acetic acid concentration was lower than 30 g/L. In the fermentation, more than 70% 5-hydroxymethylfurfural was converted to 2,5-furandimethanol. All furfural and the rest of 5-hydroxymethylfurfural were metabolized by Klebsiella oxytoca. It showed that in the detoxification process of 2,3-butanediol production using lignocelluloses hydrolysate, furfural should be given priority to remove and a certain concentration of acetic acid is not need to removal.

Wu J; Cheng K; Li W; Feng J; Zhang J

2013-03-01

113

Determination of gaseous formic acid and acetic acid by pulsed ultraviolet photoacoustic spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

The quantitative determination of gaseous formic acid and acetic acid by photoacoustic spectroscopy (PAS) using pulsed laser excitation in the ultraviolet is reported. Instrumentation utilizing continuously tunable laser excitation in the 220-nm wavelength region is used to record time-resolved PA signals from samples of each acid. Detection limits of 140 ppbv for formic acid and 120 ppbv for acetic acid in dry nitrogen at one atmosphere total pressure are attained. Considerable background signal originating from atmospheric oxygen is found to impose limitations on the detection sensitive with air samples.

Cvijin, P.V.; Gilmore, D.A.; Atkinson, G.H.

1988-07-01

114

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

115

Benzylidene acetal type bridged nucleic acids: changes in properties upon cleavage of the bridge triggered by external stimuli.  

UK PubMed Central (United Kingdom)

Four classes of benzylidene acetal type bridged nucleic acids (BA-BNAs) were designed with 2',4'-bridged structures that cleaved upon exposure to appropriate external stimuli. Cleavage of 6-nitroveratrylidene and 2-nitrobenzylidene acetal type BNA bridges occurred upon photoirradiation and subsequent treatment with thiol caused changes in secondary structure to afford 4'-C-hydroxymethyl RNA. Benzylidene and 4-nitrobenzylidene acetal type BNA responded to acids and reducing agents, respectively, resulting in hydrolysis of the acetal-bridged structure. Cleavage of the bridge removed sugar conformational restrictions and changed the duplex- and triplex-forming properties of the BNA-modified oligonucleotides. Moreover, oligonucleotides incorporating a single BA-BNA modification had considerably improved stability toward 3'-exonuclease, which was lost upon cleavage of the bridge. Thus, these new BNAs may be useful as therapeutic and detection tools by sensing various environments.

Morihiro K; Kodama T; Obika S

2011-07-01

116

Benzylidene acetal type bridged nucleic acids: changes in properties upon cleavage of the bridge triggered by external stimuli.  

Science.gov (United States)

Four classes of benzylidene acetal type bridged nucleic acids (BA-BNAs) were designed with 2',4'-bridged structures that cleaved upon exposure to appropriate external stimuli. Cleavage of 6-nitroveratrylidene and 2-nitrobenzylidene acetal type BNA bridges occurred upon photoirradiation and subsequent treatment with thiol caused changes in secondary structure to afford 4'-C-hydroxymethyl RNA. Benzylidene and 4-nitrobenzylidene acetal type BNA responded to acids and reducing agents, respectively, resulting in hydrolysis of the acetal-bridged structure. Cleavage of the bridge removed sugar conformational restrictions and changed the duplex- and triplex-forming properties of the BNA-modified oligonucleotides. Moreover, oligonucleotides incorporating a single BA-BNA modification had considerably improved stability toward 3'-exonuclease, which was lost upon cleavage of the bridge. Thus, these new BNAs may be useful as therapeutic and detection tools by sensing various environments. PMID:21644240

Morihiro, Kunihiko; Kodama, Tetsuya; Obika, Satoshi

2011-06-03

117

A novel fermentation pathway in an Escherichia coli mutant producing succinic acid, acetic acid, and ethanol.  

Energy Technology Data Exchange (ETDEWEB)

Escherichia coli strain NZN111, which is unable to grow fermentatively because of insertional inactivation of the genes encoding pyruvate: formate lyase and the fermentative lactate dehydrogenase, gave rise spontaneously to a chromosomal mutation that restored its ability to ferment glucose. The mutant strain, named AFP111, fermented glucose more slowly than did its wild-type ancestor, strain W1485, and generated a very different spectrum of products. AFP111 produced succinic acid, acetic acid, and ethanol in proportions of approx 2:1:1. Calculations of carbon and electron balances accounted fully for the observed products; 1 mol of glucose was converted to 1 mol of succinic acid and 0.5 mol each of acetic acid and ethanol. The data support the emergence in E.coli of a novel succinic acid:acetic acid:ethanol fermentation pathway.

Donnelly, M. I.; Millard, C. S.; Clark, D. P.; Chen, M. J.; Rathke, J. W.; Southern Illinois Univ.

1998-04-01

118

Gas Cluster Ion Beam Etching under Acetic Acid Vapor for Etch-Resistant Material  

Science.gov (United States)

Gas cluster ion beam (GCIB) etching of etch-resistant materials under acetic acid vapor was studied for development of new manufacturing process of future nonvolatile memory. Etching depths of various etch-resistant materials (Pt, Ru, Ta, CoFe) with acetic acid vapor during O2-GCIB irradiations were 1.8--10.7 times higher than those without acetic acid. Also, etching depths of Ru, Ta, CoFe by Ar-GCIB with acetic acid vapor were 2.2--16.1 times higher than those without acetic acid. Even after etching of Pt, smoothing of Pt was realized using O2-GCIB under acetic acid. From XPS and angular distribution of sputtered Pt, it was shown that PtOx layer was formed on Pt after O2-GCIB irradiation. PtOx reacted with acetic acid by GCIB bombardments; as a result, increase of etching depth was observed.

Yamaguchi, Akira; Hinoura, Ryo; Toyoda, Noriaki; Hara, Ken-ichi; Yamada, Isao

2013-05-01

119

Anion exchange process in acetic acid medium as a reconversion method for reprocessing of J-rods  

International Nuclear Information System (INIS)

In the earlier reprocessing campaign of J-rods (thorium metal and oxide pellets contained in Al cans; irradiated in the Cirus reactor), two reconversion methods namely anion exchange process in hydrochloric acid medium and oxalate precipitation route were followed. The product solution of 233U contained about 5% iron in addition to thorium impurity. In both the methods, thorium could be removed whereas iron impurity remained. Removal of iron impurity from the 233U oxide product required a subsequent solvent extraction method. In the present method of anion exchange separation, in acetic acid medium, both thorium and iron impurities are removed avoiding a separate solvent extraction purification. (author). 4 refs.

1997-01-01

120

Utilization of catalytic hydrolysis of ethyl acetate for solvent removal during microencapsulation.  

UK PubMed Central (United Kingdom)

The objective of this study was to apply the specific acid-catalysed hydrolysis of ethyl acetate to completing solvent extraction during an emulsion-based microencapsulation process. The dispersed phase consisting of poly-D,L-lactide-co-glycolide and ethyl acetate was emulsified in an acid catalyst containing aqueous phase. Catalytic hydrolysis of ethyl acetate led to its continual leaching from the dispersed phase of the emulsion, thereby triggering microsphere hardening with high efficiency. Ketoprofen was successfully encapsulated into microspheres via this technique, and liquid chromatography-mass spectrometry showed that its structural integrity was preserved during microencapsulation. Compared to typical solvent extraction approaches, the acid-catalysis technique helped minimize the consumption of a quench liquid. Also, the resultant microspheres displayed excellent dispersibility and decreased propensity for aggregation. Furthermore, the new method provided better drug encapsulation efficiency and lower levels of residual ethyl acetate in microspheres. In conclusion, the acid-catalysis approach had great potential for the preparation of versatile microspheres and nanoparticles.

Lee M; Kang J; Sah H

2013-01-01

 
 
 
 
121

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

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

122

Indole-3-acetic acid and 2-(indol-3-ylmethyl)indol-3-yl acetic acid in the thermophilic archaebacterium Sulfolobus acidocaldarius.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Indole-3-acetic acid (IAA) and 2-(indol-3-ylmethyl)indol-3-yl acetic acid were identified in lipid extracts of Sulfolobus acidocaldarius; they occurred at concentrations of 0.57 and 0.59 mumol/g (dry weight), respectively. The amount of IAA found in these cells is more than a thousand times greater ...

White, R H

123

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

124

Characteristics of chitosan-lithium acetate-palmitic acid complexes  

Energy Technology Data Exchange (ETDEWEB)

A new host polymer electrolyte with sufficiently high ionic conductivity was developed using chitosan, palmitic acid and lithium acetate, using the solution cast technique. The new electrolyte fits the requirements of lithium polymer batteries, and takes into account the need for a long cycle life for safe practical use and environmental friendliness. The room temperature ionic conductivity of the complexes was measured by the technique of impedance spectroscopy. The conductivity of the LiOAc-doped chitosan polymer was also studied as a function of temperature between 3003 degrees K and 363 degrees K. 28 refs., 1 tab., 7 figs.

Yahya, M. Z. A. [MARA Univ. of Technology, Selangor (Malaysia); Arof, A. K. [Malaya Univ. Physics Dept., Kuala Lumpur (Malaysia)

2002-04-01

125

Indole 3-acetic acid production by ectomycorrhizal fungi.  

UK PubMed Central (United Kingdom)

Ability of 8 ectomycorrhizal fungi to synthesise indole 3-acetic acid from L-tryptophan and their growth rate were studied. Differences in the levels of IAA synthesis and biomass production among the 8 mycorrhizal fungi were observed. A positive correlation was recorded between IAA level and mycelial growth. The synthesis of IAA and mycelial biomass were maximum on 30th day after incubation. Pisolithus tinctorius and Laccaria laccata exhibited higher amounts of IAA production than other fungi, whereas Amanita muscaria and Rhizopogon luteolus showed least quantity of IAA.

Gopinathan S; Raman N

1992-02-01

126

Kinetic Modeling of Esterification of Ethylene Glycol with Acetic Acid  

International Nuclear Information System (INIS)

The reaction kinetics of the esterification of ethylene glycol with acetic acid in the presence of cation exchange resin has been studied and kinetic models based on empirical and Langmuir approach has been developed. The Langmuir based model involving eight kinetic parameters fits experimental data much better compared to empirical model involving four kinetic parameters. The effect of temperature and catalyst loading on the reaction system has been analyzed. Further, the activation energy and frequency factor of the rate constants for Langmuir based model has been estimated.

2010-10-26

127

Fluorinated piperidine acetic acids as gamma-secretase modulators.  

UK PubMed Central (United Kingdom)

We report herein a novel series of difluoropiperidine acetic acids as modulators of gamma-secretase. Synthesis of 2-aryl-3,3-difluoropiperidine analogs was facilitated by a unique and selective beta-difluorination with Selectfluor. Compounds 1f and 2c were selected for in vivo assessment and demonstrated selective lowering of Abeta42 in a genetically engineered mouse model of APP processing. Moreover, in a 7-day safety study, rats treated orally with compound 1f (250mg/kg per day, AUC(0-24)=2100microMh) did not exhibit Notch-related effects.

Stanton MG; Hubbs J; Sloman D; Hamblett C; Andrade P; Angagaw M; Bi G; Black RM; Crispino J; Cruz JC; Fan E; Farris G; Hughes BL; Kenific CM; Middleton RE; Nikov G; Sajonz P; Shah S; Shomer N; Szewczak AA; Tanga F; Tudge MT; Shearman M; Munoz B

2010-01-01

128

Actinide Removal from Nitric Acid Waste Streams.  

Science.gov (United States)

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 breakthroug...

A. C. Muscatello J. D. Navratil

1986-01-01

129

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

130

Prospective randomised single-blind controlled trial of glacial acetic acid versus glacial acetic acid, neomycin sulphate and dexamethasone spray in otitis externa and infected mastoid cavities.  

UK PubMed Central (United Kingdom)

OBJECTIVES: The literature reports the merits of antibacterial, antibiotic and steroid agents in treating otological infections but no controlled clinical trial has directly compared 2% glacial acetic acid (EarCalm; Stafford-Miller Ltd, Brentford, UK) against 2% glacial acetic acid, 0.1% dexamethasone and 3250 U/ml of neomycin sulphate (Otomize; Stafford-Miller Ltd) in the treatment of otitis externa and infected mastoid cavities. DESIGN: Prospective, single-blind randomised controlled trial. SETTING: Outpatients, Derby Royal Infirmary, Derby, UK. PATIENTS: Emergency and GP referrals with acute otitis externa (n = 53) and infected mastoid cavities (n = 56). MAIN OUTCOME MEASURES: Otoscopy was performed at initial randomisation and then at 2 and 4 weeks, the ear assessed for active and inactive disease. RESULTS: Patients with active otitis externa, 71% (15/21) resolved with glacial acetic acid, dexamethasone and of neomycin sulphate after 2 weeks, increasing to 86% (18/21) after 4 weeks treatment. Patients on glacial acetic acid had only 38% (12/32) resolution after 4 weeks (P < 0.0005). Two per cent glacial acetic acid, dexamethasone and neomycin sulphate resolved only 30% (8/27) of infected mastoid cavities compared to only 10% (3/29) on glacial acetic acid (P < 0.07). A further 2 weeks treatment this increased to 67%, (18/27) with glacial acetic acid, dexamethasone and neomycin sulphate and 48% (14/29) with glacial acetic acid. These results are not statistically significant. CONCLUSION: Glacial acetic acid, dexamethasone and neomycin sulphate is significantly more effective in treating otitis externa when compared with glacial acetic acid. This effect failed to be significant in the infected mastoid cavities group. We therefore recommend that in conjunction with aural toilet, antibiotic/steroid combination is more effective than an antibacterial agent for otitis externa. Larger numbers of infected mastoid cavities are required to be studied.

Johnston MN; Flook EP; Mehta D; Mortimore S

2006-12-01

131

SELECTIVE PREPARATION PROCESS OF ACETIC ACID AND CATALYSTS THEREFOR  

UK PubMed Central (United Kingdom)

A process for selectively preparing acetic acid from a feed gas substance such as ethane, ethylene or mixtures thereof, as well as oxygen, at an increased temperature, is disclosed. The feed gas substance is brought together with a catalyst which contains the elements Mo, Pd, X and Y in the gram-atomic ratio a:b:c:d in combination with oxygen, according to formula (I) in which MoaPdbXcYd. The symbols X and Y have the following meanings: X stands for one or several elements selected from the group composed of Cr, Mn, Nb, Ta, Ti, V, Te and/or W, in particular Nb, V and W; Y stands for one or several elements selected from the group composed of B, Al, Ga, In, Pt, Zn, Cd, Bi, Ce, Co, Cu, Rh, Ir, Au, Ag, Fe, Ru, Os, K, Rb, Cs, Mg, Ca, Sr, Ba, Sr, Ba, Zr, Hf, Ni, P, Pb, Sb, Si, Sn, Tl and U, in particular Ca, Sb, Te and Li.; Also disclosed is a catalyst for selectively preparing acetic acid which contains the elements Mo, Pd, X and Y in the gram-atomic ratio a:b:c:d in combination with oxygen. The indices a, b, c and x represent the gram-atomic ratio of the corresponding elements, and a = 1; b > 0, and d = 0.05-2.

BORCHERT HOLGER; DINGERDISSEN UWE

132

Unusal pattern of product inhibition: batch acetic acid fermentation  

Energy Technology Data Exchange (ETDEWEB)

The limited tolerance of microorganisms to their metabolic products results in inhibited growth and product formation. The relationship between the specific growth rate, micro, and the concentration of an inhibitory product has been described by a number of mathematical models. In most cases, micro was found to be inversely proportional to the product concentration and invariably the rate of substrate utilization followed the same pattern. In this communication, the authors report a rather unusual case in which the formation rate of a product, acetic acid, increased with a decreasing growth rate of the microorganism, Acetobacter aceti. Apparently, a similar behavior was mentioned in a review report with respect to Clostridium thermocellum in a batch culture but was not published in the freely circulating literature. The fermentation of ethanol to acetic acid, C/sub 2/H/sub 5/OH + O/sub 2/ = CH/sub 3/COOH + H/sub 2/O is clearly one of the oldest known fermentations. Because of its association with the commercial production of vinegar it has been a subject of extensive but rather technically oriented studies. Suprisingly, the uncommon uncoupling between the inhibited microbial growth and the product formation appears to have been unnoticed. 13 references.

Bar, R.; Gainer, J.L.; Kirwan, D.J.

1987-04-20

133

The dynamics of acetic acid in the anaerobic treatment of abattoir sewage; Dinamica del acido acetico en la depuracion anaerobia de aguas residuales de mataderos  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this experiment was to examine the production and consumption of acetic acid during the anaerobic treatment of sewage from a municipal abattoir. The experiment studied a 20-litre UASB reactor under three hydraulic retention time (HRT) conditions-4 days, 2.5 days and 1.6 days-measuring the acetic acid concentration in the reactor in fluent and effluent. The results obtained during the experiment with the three different HRTs are reported. The highest percentages of acetic acid removed ( an average of 44%) were obtained with an HRT of 4 days. The amount of acetic acid removed with and HRT of 2.5 days was 27%. (Author) 18 refs.

Vazquez Borges, E.; Acosta Viana, K. [Universidad Autonoma de Yucatan. Mexico (Mexico)

1999-05-01

134

Antimicrobial compositions comprising acetic acid, vinegar, or citric acid, and EDTA, and methods of use thereof  

UK PubMed Central (United Kingdom)

Disclosed is the use of a composition comprising EDTA and at least two of citric acid, acetic acid, and vinegar, wherein the pH of the composition is between 2.5 and 4.5, for reducing an existing bacterial infection or superinfection.

DOSCH MICHAEL H; OSTERMANN KURT

135

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

136

Recent advances in nitrogen-fixing acetic acid bacteria.  

UK PubMed Central (United Kingdom)

Nitrogen is an essential plant nutrient, widely applied as N-fertilizer to improve yield of agriculturally important crops. An interesting alternative to avoid or reduce the use of N-fertilizers could be the exploitation of plant growth-promoting bacteria (PGPB), capable of enhancing growth and yield of many plant species, several of agronomic and ecological significance. PGPB belong to diverse genera, including Azospirillum, Azotobacter, Herbaspirillum, Bacillus, Burkholderia, Pseudomonas, Rhizobium, and Gluconacetobacter, among others. They are capable of promoting plant growth through different mechanisms including (in some cases), the biological nitrogen fixation (BNF), the enzymatic reduction of the atmospheric dinitrogen (N(2)) to ammonia, catalyzed by nitrogenase. Aerobic bacteria able to oxidize ethanol to acetic acid in neutral or acid media are candidates of belonging to the family Acetobacteraceae. At present, this family has been divided into ten genera: Acetobacter, Gluconacetobacter, Gluconobacter, Acidomonas, Asaia, Kozakia, Saccharibacter, Swaminathania, Neoasaia, and Granulibacter. Among them, only three genera include N(2)-fixing species: Gluconacetobacter, Swaminathania and Acetobacter. The first N(2)-fixing acetic acid bacterium (AAB) was described in Brazil. It was found inside tissues of the sugarcane plant, and first named as Acetobacter diazotrophicus, but then renamed as Gluconacetobacter diazotrophicus. Later, two new species within the genus Gluconacetobacter, associated to coffee plants, were described in Mexico: G. johannae and G. azotocaptans. A salt-tolerant bacterium named Swaminathania salitolerans was found associated to wild rice plants. Recently, N(2)-fixing Acetobacter peroxydans and Acetobacter nitrogenifigens, associated with rice plants and Kombucha tea, respectively, were described in India. In this paper, recent advances involving nitrogen-fixing AAB are presented. Their natural habitats, physiological and genetic aspects, as well as their association with different plants and contribution through BNF are described as an overview.

Pedraza RO

2008-06-01

137

Recent advances in nitrogen-fixing acetic acid bacteria.  

Science.gov (United States)

Nitrogen is an essential plant nutrient, widely applied as N-fertilizer to improve yield of agriculturally important crops. An interesting alternative to avoid or reduce the use of N-fertilizers could be the exploitation of plant growth-promoting bacteria (PGPB), capable of enhancing growth and yield of many plant species, several of agronomic and ecological significance. PGPB belong to diverse genera, including Azospirillum, Azotobacter, Herbaspirillum, Bacillus, Burkholderia, Pseudomonas, Rhizobium, and Gluconacetobacter, among others. They are capable of promoting plant growth through different mechanisms including (in some cases), the biological nitrogen fixation (BNF), the enzymatic reduction of the atmospheric dinitrogen (N(2)) to ammonia, catalyzed by nitrogenase. Aerobic bacteria able to oxidize ethanol to acetic acid in neutral or acid media are candidates of belonging to the family Acetobacteraceae. At present, this family has been divided into ten genera: Acetobacter, Gluconacetobacter, Gluconobacter, Acidomonas, Asaia, Kozakia, Saccharibacter, Swaminathania, Neoasaia, and Granulibacter. Among them, only three genera include N(2)-fixing species: Gluconacetobacter, Swaminathania and Acetobacter. The first N(2)-fixing acetic acid bacterium (AAB) was described in Brazil. It was found inside tissues of the sugarcane plant, and first named as Acetobacter diazotrophicus, but then renamed as Gluconacetobacter diazotrophicus. Later, two new species within the genus Gluconacetobacter, associated to coffee plants, were described in Mexico: G. johannae and G. azotocaptans. A salt-tolerant bacterium named Swaminathania salitolerans was found associated to wild rice plants. Recently, N(2)-fixing Acetobacter peroxydans and Acetobacter nitrogenifigens, associated with rice plants and Kombucha tea, respectively, were described in India. In this paper, recent advances involving nitrogen-fixing AAB are presented. Their natural habitats, physiological and genetic aspects, as well as their association with different plants and contribution through BNF are described as an overview. PMID:18177965

Pedraza, Raúl O

2007-12-05

138

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 fo...

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

139

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

140

Leaching of spent lead acid battery paste components by sodium citrate and acetic acid.  

UK PubMed Central (United Kingdom)

A sustainable method, with minimal pollution and low energy cost in comparison with the conventional smelting methods, is proposed for treating components of spent lead-acid battery pastes in aqueous organic acid(s). In this study, PbO, PbO2, and PbSO4, the three major components in a spent lead paste, were individually reacted with a mixture of aqueous sodium citrate and acetic acid solution. Pure lead citrate precursor of Pb3(C6H5O7)2 · 3H2O is the only product crystallized in each leaching experiment. Conditions were optimized for individual lead compounds which were then used as the basis for leaching real industrial spent paste. In this work, efficient leaching process is achieved and raw material cost is reduced by using aqueous sodium citrate and acetic acid, instead of aqueous sodium citrate and citric acid as reported in a pioneering hydrometallurgical method earlier. Acetic acid is not only cheaper than citric acid but is also more effective in aiding dissolution of the lead compounds thus speeding up the leaching process in comparison with citric acid. Lead citrate is readily crystallized from the aqueous solution due to its low solubility and can be combusted to directly produce leady oxide as a precursor for making new battery pastes.

Zhu X; He X; Yang J; Gao L; Liu J; Yang D; Sun X; Zhang W; Wang Q; Kumar RV

2013-04-01

 
 
 
 
141

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 positive. The sensitivity of acetic acid test was 72.4%, specificity 54% and false negative rate 15.2%, as compared to papanicolaou test which had a sensitivity of 13.2%, specificity of 96.3% and false negative rate of 24.4%. The advantage of the acetic acid test lies in its easy technique, low cost and high sensitivity which are important factors for determining the efficacy of any screening programme in developing countries.

Londhe M; George S; Seshadri L

1997-01-01

142

Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid  

Energy Technology Data Exchange (ETDEWEB)

Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid were developed. High titer antibodies, having a well-defined high specificity, have been raised by coupling the side-chain of both molecules to human serum albumin. Serotonin is first converted into N-hemisuccinate, and then treated like 5-HIAA, namely, conjugated with HSA for the immunogen. Synthesis of /sup 125/I iodinated analogues was performed by coupling 5-HIAA or N-succinyl serotonin to glycyltyrosine, without any contact between both molecules and the oxidizing reagents. Chemical conversions of biological samples (by succinylation for 5-HT and amidation for 5-HIAA) were carried out. This critical step makes the antigen molecules resemble the immunogen more closely, thus allowing an appreciable gain in specificity and sensitivity. These assays allow the rapid determination of 5-HT and 5-HIAA in small amounts of tissue, blood, cerebral spinal fluid or perfusate without any purification, with a sensitivity threshold of 50 pg.

Delaage, M.A. (Centre National de la Recherche Scientifique, 13 - Marseille (France)); Puizillout, J.J. (INSERM, 13 - Marseille (France))

1981-01-01

143

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

144

Actinide removal from nitric acid waste streams  

Energy Technology Data Exchange (ETDEWEB)

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.

Muscatello, A.C.; Navratil, J.D.

1987-10-15

145

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.

SM Sharafi; I Rasooli; K Beheshti-Maal

2010-01-01

146

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

UK PubMed Central (United Kingdom)

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. MATERIALS 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. RESULTS: 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 12°C for more than a month. Longer preservation was possible at -70°C. CONCLUSION: 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.

Sharafi S; Rasooli I; Beheshti-Maal K

2010-03-01

147

Smear layer removal with citric acid solution  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to evaluate efficacy in smear layer removal of 17% EDTA and 10% citric acid, using SEM. Material and method: Twenty human, extracted teeth with a single root canal were examined. Whilst instrumentation with step-back technique and manual K files, root canals were irrigated with 2 ml of 2.5% NaOCl, between each file size. After instrumentatio n, specimens were divided into two groups. The first group was irrigated with a final flush of 17% EDTA, during one minute, and the second group was irrigated with a 10% citric acid. Results: Irrigation with 17% EDTA and 10% citric acid removed smear layer from the root canals walls. There was not statistically significant differences (p>0.05) in cleaning ability between EDTA and citric acid groups.

Petrovi? Violeta; Živkovi? Slavoljub

2005-01-01

148

Solvent effect on the acid-catalyzed hydrolysis reaction of poly(vinyl acetate)  

Energy Technology Data Exchange (ETDEWEB)

Poly(vinyl acetate) was hydrolyzed in acetic acid / water medium with hydrochloric acid as the catalyst to produce random poly(vinyl acetate-co-vinyl alcohol) copolymers. Mole fractions of vinyl alcohol (VA) and vinyl acetate (VAc) at various water/(acetic acid) ratio were determined via titration and NMR, and the equilibrium constant K{sub 2q} of the reaction was studied. K{sub eq} was constant, 0.75 ({+-}0.06), when the reaction solvent was dominated by acetic acid, but it showed a deviation when the water mole fraction in the reaction medium was larger than 0.70. We attribute the deviation to the hydrophobic interaction.

Park, S.S.; Huh, S.J. [University of Ulsan College of Medicine (Korea, Republic of); Yoon, H.S.; Woo, K.W. [Seoul National University, Seoul (Korea, Republic of)

1998-03-01

149

Removal of ovarian hormones affects the ageing process of acetate metabolism  

Directory of Open Access Journals (Sweden)

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.

Yoshihisa Urita; Toshiyasu Watanabe; Tsunehiko Imai; Yasuyuki Miura; Naohiro Washizawa; Masaki Sanaka; Hitoshi Nakajima; Motonobu Sugimoto

2009-01-01

150

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

Directory of Open Access Journals (Sweden)

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; Prado René Gamberini; Hossne William Saad

2006-01-01

151

Investigation of radiolytic gas formation in nitric acid and acetic acid solutions  

International Nuclear Information System (INIS)

Gas-formation processes by ?-radiolysis of aqueous solutions, containing HNO3, NaNO3 and CH3COOH are studied. H2, O2, N2, N2O, CO2 and CH4 are determined by chromatographic and spectrographic methods among the radiolysis products. It is shown that introduction of acetic acid into nitric acid solutions leads to essential increase in gas release and growth of radiation-chemical yield of nitrogen oxide

1997-01-01

152

Genome-wide identification of Saccharomyces cerevisiae genes required for tolerance to acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S. cerevisiae tolerance to acetic acid is essential for the rational selection of optimal fermentation conditions and the engineering of more robust industrial strains to be used in processes in which yeast is explored as cell factory. Results The yeast genes conferring protection against acetic acid were identified in this study at a genome-wide scale, based on the screening of the EUROSCARF haploid mutant collection for susceptibility phenotypes to this weak acid (concentrations in the range 70-110 mM, at pH 4.5). Approximately 650 determinants of tolerance to acetic acid were identified. Clustering of these acetic acid-resistance genes based on their biological function indicated an enrichment of genes involved in transcription, internal pH homeostasis, carbohydrate metabolism, cell wall assembly, biogenesis of mitochondria, ribosome and vacuole, and in the sensing, signalling and uptake of various nutrients in particular iron, potassium, glucose and amino acids. A correlation between increased resistance to acetic acid and the level of potassium in the growth medium was found. The activation of the Snf1p signalling pathway, involved in yeast response to glucose starvation, is demonstrated to occur in response to acetic acid stress but no evidence was obtained supporting the acetic acid-induced inhibition of glucose uptake. Conclusions Approximately 490 of the 650 determinants of tolerance to acetic acid identified in this work are implicated, for the first time, in tolerance to this weak acid. These are novel candidate genes for genetic engineering to obtain more robust yeast strains against acetic acid toxicity. Among these genes there are number of transcription factors that are documented regulators of a large percentage of the genes found to exert protection against acetic acid thus being considered interesting targets for subsequent genetic engineering. The increase of potassium concentration in the growth medium was found to improve the expression of maximal tolerance to acetic acid, consistent with the idea that the adequate manipulation of nutrient concentration of industrial growth medium can be an interesting strategy to surpass the deleterious effects of this weak acid in yeast cells.

Mira Nuno P; Palma Margarida; Guerreiro Joana F; Sá-Correia Isabel

2010-01-01

153

Vinegar as a burn-down herbicide: Acetic acid concentrations, application volumes, and adjuvants  

Science.gov (United States)

Acetic acid acts as a contact herbicide, injuring and killing plants by first destroying the cell membranes, which causes the rapid desiccation of the plant tissues. Vinegars with acetic acid concentrations of 11% or greater can burn the skin and cause serious to severe eye injury, including blindn...

154

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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....

Voss, Bodil; Schjødt, Niels Christian; Grunwaldt, Jan-Dierk; Andersen, Simon Ivar; Woodley, John

155

Production and Optimization of Indole Acetic Acid by Indigenous Micro Flora using Agro Waste as Substrate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Indole Acetic Acid (IAA) producing bacterium was isolated from the Rhizosphere soil and identified as Rhizobium sp. and Bacillus sp., Optimization of Indole acetic acid production was carried out at different cultural conditions, such as pH, temperature and substrate with Rhizobium ...

M. Sudha; R. Shyamala Gowri; P. Prabhavathi; P. Astapriya; S. Yamuna Devi; A. Saranya

156

Spectroscopic Evidence for Complexing of Acetic Acid with Bovine Serum Albumin, Gramicidin, and Dimethylformamide  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Acetic acid has a major effect on the absorption spectra of bovine serum albumin, gramicidin, and dimethylformamide in the region, 255 to 200 m?. Increasing the concentration of acetic acid causes progressively decreasing absorbency accompanied by a large and progressively increasing red shift of th...

Cann, John R.

157

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

158

Influence of acetic acid on a pap smear of dysplastic lesion.  

UK PubMed Central (United Kingdom)

BACKGROUND: Cervical cancer prevention is performed by taking Pap smears. The correct execution of the smear is crucial as an inadequate smear might result in underdiagnosis. The second means of cervical cancer prevention is visual inspection of the cervix uteri with acetic acid, while often both methods are combined. We investigated whether the application of acetic acid compromises the Pap smear. PATIENTS AND METHODS: A total of 100 patients with dysplasia were prospectively included; Pap smears were obtained before and after the application of acetic acid. RESULTS: We observed an alteration of the result of the Pap smear after acetic acid application in 41%. However, these alterations did not result in a dysplastic case being classed as a normal smear or vice versa. CONCLUSION: The application of acetic acid to the transformation zone of the cervix uteri may enhance changes of the Pap smear in dysplasia, however, the changes affect subgroups of dysplasia and thus do not change therapeutic management.

Hoellen F; Bohlmann MK; Brade J; Rody A; Diedrich K; Husstedt WD; Hornemann A

2013-03-01

159

[Diversity of endophytic bacteria in rice seeds and their secretion of indole acetic acid].  

UK PubMed Central (United Kingdom)

OBJECTIVE: This study aimed to investigate the diversity of endophytic bacteria isolated from rice seeds, and screen indole acetic acid secrecting srtains. METHOD: Conventional culture-dependent methods were used to isolate the endopytic bacteria from rice seeds. Phylogenetic analysis was done based on partial 16s rRNA gene sequences. The ability to indole acetic acid secretion of tested strains was analyzed qualitatively and quantitatively by colorimetry. RESULT: In total 66 isolates were identified as belonging to 26 species of 15 genera of 5 phyla. Of them 26 strains were chosen to test indole acetic acid secretion. Four isolates had more ability of indole acetic acid secretion; they belonged to the genera of Staphylococcus, Rhizobium, Microbacterium and Methylobacterium. CONCLUSION: The endophytic bacteria in rice seeds are diverse. Some of them could produce indole acetic acid.

Jiang X; Gao J; Xu F; Cao Y; Tang X; Zhang X

2013-03-01

160

Ethenzamide-gentisic acid-acetic acid (2/1/1).  

UK PubMed Central (United Kingdom)

In the title co-crystal solvate, 2-ethoxy-benzamide-2,5-dihydroxy-benzoic acid-ethanoic acid (2/1/1), 2C(9)H(11)NO(2)·C(7)H(6)O(4)·C(2)H(4)O(2), two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxy-benzamide) and gentisic acid (systematic name: 2,5-dihydroxy-benzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component mol-ecular assembly held together by N-H?O and O-H?O hydrogen bonds. This assembly features two symmetry-independent mol-ecules of ethenzamide, forming supra-molecular acid-amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O-H?O [O?O = 2.5446?(15) and 2.5327?(15)?Å] and less strong N-H?O [N?O = 2.9550?(17) and 2.9542?(17)?Å] hydrogen bonds. The overall crystal packing features several C-H?O and ?-? stacking inter-actions [centroid-centroid distance = 3.7792?(11)?Å].

Aitipamula S; Chow PS; Tan RB

2010-01-01

 
 
 
 
161

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

Science.gov (United States)

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 symmetry-independent mol­ecules of ethenzamide, forming supra­molecular acid–amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O—H?O [O?O = 2.5446?(15) and 2.5327?(15)?Å] and less strong N—H?O [N?O = 2.9550?(17) and 2.9542?(17)?Å] hydrogen bonds. The overall crystal packing features several C—H?O and ?–? stacking inter­actions [centroid–centroid distance = 3.7792?(11)?Å].

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

2010-01-01

162

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 symmetry-independent molecules of ethenzamide, forming supramolecular acid–amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O—H...O [O...O = 2.5446?(15) and 2.5327?(15)?Å] and less strong N—H...O [N...O = 2.9550?(17) and 2.9542?(17)?Å] hydrogen bonds. The overall crystal packing features several C—H...O and ?–? stacking interactions [centroid–centroid distance = 3.7792?(11)?Å].

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

2010-01-01

163

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

International Nuclear Information System (INIS)

[en] 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)

2011-01-01

164

Neptunium salts with certain acetic acid derivatives, synthesis and properties  

International Nuclear Information System (INIS)

A study was performed to develop preparation of neptunium (V) salts with aminoacetic, glycolic, and trichloroacetic acids. Crystalline NpO2(CH2OHCOO). H2O (I) and NpO2(CC13COO).H2O (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,? - 99.83(4)degrees] were determined, and IR and electronic absorption spectra were measured. The main band of NpO+2ion (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 NpO2. At 210 degrees C, compound II is converted into intermediate NpOC12, which then decomposes to NpO2. Main physiochemical properties of I and II were compared with properties of Np(V) acetate.

1995-01-01

165

Mechanism of anodic dissolution of iron in acetic acid solution  

International Nuclear Information System (INIS)

[en] 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 O2. Acidic solution (20%) of sodium acetate (pH=3.7) and Fe59 isotope produced by neutron irradiation were used to measure the corrosion rate of iron containing 0.005% carbon. The iron dissolves electrochemically as Fe?Fe2++2e, measured by the ER methods. The Fe3++e?Fe2+ reaction and the autocatalytic dissolution of iron were proved as well. The elementary steps of the chemical reaction: 4Fe2++O2+4H+?4Fe3++2H2O were experimentally verified. It has been demonstrated by both methods that the reduction of Fe3+ ions at the electrode as well as the oxidation of Fe2+ ions by chemical reaction are processes of high speed so they may cause high corrosion rate. (Sz.J.)

1982-01-01

166

Metabolic regulation of the plant hormone indole-3-acetic acid  

Energy Technology Data Exchange (ETDEWEB)

The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research questions. A critical issue concerning the biosynthesis if IAA in plants is that redundant pathways for IAA biosynthesis exist in plants. We showed that these redundant pathways and their relative contribution to net IAA production are under both developmental and environmental control. We worked on three fundamental problems related to how plants get their IAA: 1) An in vitro biochemical approach was used to define the tryptophan dependent pathway to IAA using maize endosperm, where relatively large amounts of IAA are produced over a short developmental period. Both a stable isotope dilution and a protein MS approach were used to identify intermediates and enzymes in the reactions. 2) We developed an in vitro system for analysis of tryptophan-independent IAA biosynthesis in maize seedlings and we used a metabolite profiling approach to isolate intermediates in this reaction. 3) Arabidopsis contains a small family of genes that encode potential indolepyruvate decarboxylase enzymes. We cloned these genes and studied plants that are mutant in these genes and that over-express each member in the family in terms of the level and route of IAA biosynthesis. Together, these allowed further development of a comprehensive picture of the pathways and regulatory components that are involved in IAA homeostasis in higher plants.

Jerry D. Cohen

2009-11-01

167

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

168

Acetic Acid Bacteria, Newly Emerging Symbionts of Insects?  

Science.gov (United States)

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 sacchari have been found to be associated with the bacterial genera Acetobacter, Gluconacetobacter, Gluconobacter, Asaia, and Saccharibacter and the novel genus Commensalibacter. AAB establish symbiotic associations with the insect midgut, a niche characterized by the availability of diet-derived carbohydrates and oxygen and by an acidic pH, selective factors that support AAB growth. AAB have been shown to actively colonize different insect tissues and organs, such as the epithelia of male and female reproductive organs, the Malpighian tubules, and the salivary glands. This complex topology of the symbiosis indicates that AAB possess the keys for passing through body barriers, allowing them to migrate to different organs of the host. Recently, AAB involvement in the regulation of innate immune system homeostasis of Drosophila has been shown, indicating a functional role in host survival. All of these lines of evidence indicate that AAB can play different roles in insect biology, not being restricted to the feeding habit of the host. The close association of AAB and their insect hosts has been confirmed by the demonstration of multiple modes of transmission between individuals and to their progeny that include vertical and horizontal transmission routes, comprising a venereal one. Taken together, the data indicate that AAB represent novel secondary symbionts of insects.

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

169

Acetic acid bacteria, newly emerging symbionts of insects.  

Science.gov (United States)

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 sacchari have been found to be associated with the bacterial genera Acetobacter, Gluconacetobacter, Gluconobacter, Asaia, and Saccharibacter and the novel genus Commensalibacter. AAB establish symbiotic associations with the insect midgut, a niche characterized by the availability of diet-derived carbohydrates and oxygen and by an acidic pH, selective factors that support AAB growth. AAB have been shown to actively colonize different insect tissues and organs, such as the epithelia of male and female reproductive organs, the Malpighian tubules, and the salivary glands. This complex topology of the symbiosis indicates that AAB possess the keys for passing through body barriers, allowing them to migrate to different organs of the host. Recently, AAB involvement in the regulation of innate immune system homeostasis of Drosophila has been shown, indicating a functional role in host survival. All of these lines of evidence indicate that AAB can play different roles in insect biology, not being restricted to the feeding habit of the host. The close association of AAB and their insect hosts has been confirmed by the demonstration of multiple modes of transmission between individuals and to their progeny that include vertical and horizontal transmission routes, comprising a venereal one. Taken together, the data indicate that AAB represent novel secondary symbionts of insects. PMID:20851977

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

2010-09-17

170

Acetic acid bacteria, newly emerging symbionts of insects.  

UK PubMed Central (United Kingdom)

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 sacchari have been found to be associated with the bacterial genera Acetobacter, Gluconacetobacter, Gluconobacter, Asaia, and Saccharibacter and the novel genus Commensalibacter. AAB establish symbiotic associations with the insect midgut, a niche characterized by the availability of diet-derived carbohydrates and oxygen and by an acidic pH, selective factors that support AAB growth. AAB have been shown to actively colonize different insect tissues and organs, such as the epithelia of male and female reproductive organs, the Malpighian tubules, and the salivary glands. This complex topology of the symbiosis indicates that AAB possess the keys for passing through body barriers, allowing them to migrate to different organs of the host. Recently, AAB involvement in the regulation of innate immune system homeostasis of Drosophila has been shown, indicating a functional role in host survival. All of these lines of evidence indicate that AAB can play different roles in insect biology, not being restricted to the feeding habit of the host. The close association of AAB and their insect hosts has been confirmed by the demonstration of multiple modes of transmission between individuals and to their progeny that include vertical and horizontal transmission routes, comprising a venereal one. Taken together, the data indicate that AAB represent novel secondary symbionts of insects.

Crotti E; Rizzi A; Chouaia B; Ricci I; Favia G; Alma A; Sacchi L; Bourtzis K; Mandrioli M; Cherif A; Bandi C; Daffonchio D

2010-11-01

171

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

172

Scaleable production and separation of fermentation-derived acetic acid. Final CRADA report.  

Energy Technology Data Exchange (ETDEWEB)

Half of U.S. acetic acid production is used in manufacturing vinyl acetate monomer (VAM) and is economical only in very large production plants. Nearly 80% of the VAM is produced by methanol carbonylation, which requires high temperatures and exotic construction materials and is energy intensive. Fermentation-derived acetic acid production allows for small-scale production at low temperatures, significantly reducing the energy requirement of the process. The goal of the project is to develop a scaleable production and separation process for fermentation-derived acetic acid. Synthesis gas (syngas) will be fermented to acetic acid, and the fermentation broth will be continuously neutralized with ammonia. The acetic acid product will be recovered from the ammonium acid broth using vapor-based membrane separation technology. The process is summarized in Figure 1. The two technical challenges to success are selecting and developing (1) microbial strains that efficiently ferment syngas to acetic acid in high salt environments and (2) membranes that efficiently separate ammonia from the acetic acid/water mixture and are stable at high enough temperature to facilitate high thermal cracking of the ammonium acetate salt. Fermentation - Microbial strains were procured from a variety of public culture collections (Table 1). Strains were incubated and grown in the presence of the ammonium acetate product and the fastest growing cultures were selected and incubated at higher product concentrations. An example of the performance of a selected culture is shown in Figure 2. Separations - Several membranes were considered. Testing was performed on a new product line produced by Sulzer Chemtech (Germany). These are tubular ceramic membranes with weak acid functionality (see Figure 3). The following results were observed: (1) The membranes were relatively fragile in a laboratory setting; (2) Thermally stable {at} 130 C in hot organic acids; (3) Acetic acid rejection > 99%; and (4) Moderate ammonia flux. The advantages of producing acetic acid by fermentation include its appropriateness for small-scale production, lower cost feedstocks, low energy membrane-based purification, and lower temperature and pressure requirements. Potential energy savings of using fermentation are estimated to be approximately 14 trillion Btu by 2020 from a reduction in natural gas use. Decreased transportation needs with regional plants will eliminate approximately 200 million gallons of diesel consumption, for combined savings of 45 trillion Btu. If the fermentation process captures new acetic acid production, savings could include an additional 5 trillion Btu from production and 7 trillion Btu from transportation energy.

Snyder, S. W.; Energy Systems

2010-02-08

173

Acid treatment removes zinc sulfide scale restriction  

Energy Technology Data Exchange (ETDEWEB)

This paper reports that removal of zinc sulfide (ZnS) scale with acid restored an offshore Louisiana well's production to original rates. The zinc sulfide scale was determined to be in the near well bore area. The selected acid had been proven to control iron sulfide (FeS) scales in sour wells without causing harm to surface production equipment, tubing, and other downhole hardware. The successful removal of the blockage re-established previous production rates with a 105% increase in flowing tubing pressure. On production for a number of months, a high rate, high-pressure offshore well was experiencing unusually rapid pressure and rate declines. A small sample of the restrictive material was obtained during the wire line operations. The well was subsequently shut in while a laboratory analysis determined that zinc sulfide was the major component of the obstruction.

Biggs, K. (Kerr McGee Corp., Lafayette, LA (US)); Allison, D. (Otis Engineering Corp., Lafayette, LA (US)); Ford, W.G.F. (Halliburton Co., Duncan, OK (United States))

1992-08-31

174

Removal of fluoride from aqueous nitric acid  

International Nuclear Information System (INIS)

[en] Several methods for removing fluoride from aqueous nitric acid were investigated and compared with the frequently used aluminum nitrate-calcium nitrate (Ca2+-Al3+) 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 103 (vs approx. 500 for the Ca2+-Al3+ 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-HNO3 vapors distilled through the columns; fluoride DFs on the order of 106 and 104, respectively, were obtained. A silica gel column was very effective in adsorbing HF from HF-HNO3 solutions, producing a fluoride DF of approx. 104

1981-01-01

175

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; Prof. Suchen B. Thakore

2013-01-01

176

Absorption cross section for the 5?OH stretch of acetic acid and peracetic acid  

Science.gov (United States)

We report measurements of the absorption cross sections for the vibrational O-H stretch (5?OH) overtone transitions in glacial acetic acid and peracetic acid. The photochemistry that results from overtone excitation has been shown to lead to OH radical production in molecules containing O-H (HNO3, H2O2). In addition the overtone excitation has been observed to result in light initiated chemical reaction. A Cavity ring-down spectroscopy (CRDS) instrument comprising of an Nd:YAG pumped dye laser and 620nm high reflectivity mirrors (R=99.995%) was used to measure the cross sections. The dye laser wavelength was calibrated using water vapor spectrum and the HITRAN 2008 database. The instrument’s minimum detectable absorption is ?min =4.5 *10-9cm-1 Hz-1/2 at 2? noise level near the peak of the absorption feature. This measurement is the first for acetic acid at this excitation level. Preliminary results for acetic acid show the peak occurs near 615nm. Procedures for separating the monomer and dimer contribution will be presented. We would like to acknowledge support from NSF award #0803016 and NOAA-EPP award #NA06OAR4810187.

Begashaw, I. G.; Collingwood, M.; Bililign, S.

2009-12-01

177

Plutonium removal from nitric acid waste streams  

International Nuclear Information System (INIS)

Separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery from nitric acid waste streams generated by plutonium purifications operations. Capacity and breakthrough studies show anion exchange with Dowex 1x4 (50-100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO (tri-n-octylphosphine oxide) on XAD-4 removes the final traces of plutonium, including hydrolytic polymer. (author) 12 refs.; 3 figs.; 4 tabs.

1988-01-01

178

Plutonium removal from nitric acid waste streams  

International Nuclear Information System (INIS)

Separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery from nitric acid waste streams generated by plutonium purifications operations. Capacity and breakthrough studies show anion exchange with Dowex 1.4 (50-100 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.

1986-01-01

179

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

UK PubMed Central (United Kingdom)

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.

Gullo M; Giudici P

2008-06-01

180

An experimental study for efficacy of acetic acid as a sclerosing agent  

International Nuclear Information System (INIS)

To evaluate the efficacy of acetic acid as a sclerosing agent by observation of histologic change in urinary bladder epithelium after the instillation of acetic acid. Urinary bladder of the rabbit was catheterized with a Foley catheter, and acetic acid of 10%, 20%, 30%, 40% and 50% concentration was instilled for 5 minutes. After evacuation of the acid, the bladder was irrigated three times with normal saline. After two days, gross and histologic examinations of the bladder were performed. A bladder into which 10% acetic acid had been instilled revealed a nearly normal epithelium without denudation. In two cases, 20% acetic acid was instilled;one revealed partial denudation of the epithelium and the other revealed complete denudation. Mild to moderate interstitial edema and vascular congestion of the bladder wall were evident in all cases in which acid at a concentration of 30% or more had been instilled. In all cases in which the concentration of acid was greater than 30%, the epithelium was completely denuded. An acetic acid concentration of 40% or more is sufficient to completely destroy the epithelium of rabbit urinary bladder, and may be effective as a new sclerosing agent in cases of renal or hepatic cyst.

1997-01-01

 
 
 
 
181

An experimental study for efficacy of acetic acid as a sclerosing agent  

Energy Technology Data Exchange (ETDEWEB)

To evaluate the efficacy of acetic acid as a sclerosing agent by observation of histologic change in urinary bladder epithelium after the instillation of acetic acid. Urinary bladder of the rabbit was catheterized with a Foley catheter, and acetic acid of 10%, 20%, 30%, 40% and 50% concentration was instilled for 5 minutes. After evacuation of the acid, the bladder was irrigated three times with normal saline. After two days, gross and histologic examinations of the bladder were performed. A bladder into which 10% acetic acid had been instilled revealed a nearly normal epithelium without denudation. In two cases, 20% acetic acid was instilled;one revealed partial denudation of the epithelium and the other revealed complete denudation. Mild to moderate interstitial edema and vascular congestion of the bladder wall were evident in all cases in which acid at a concentration of 30% or more had been instilled. In all cases in which the concentration of acid was greater than 30%, the epithelium was completely denuded. An acetic acid concentration of 40% or more is sufficient to completely destroy the epithelium of rabbit urinary bladder, and may be effective as a new sclerosing agent in cases of renal or hepatic cyst.

Kim, Young Chan; Oh, Ju Hyung; Yoon, Yup; Ko, Young Tae; Choi, Woo Suk; Kim, Eui Jong; Lim, Joo Won [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)

1997-08-01

182

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

Directory of Open Access Journals (Sweden)

Full Text Available 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

183

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...

BiBi Fathemeh Mirjalili; Mohamad Ali Zolfigol; Abdolhamid Bamoniri

184

Extraction and its mechanism of diluted acetic acid by N-O, O-dialkylphosphoamidates  

International Nuclear Information System (INIS)

The N-O, O-dialkylphosphoamidates (R(1)O)2P(O)(NHR(2))(R(1), R(2): alkyl) which have the key group of both amine and TBP are used to extract acetic acid from acetic acid dilute solution. This kind of extractants can give larger distribution coefficients than amine and TBP. With the 31PNMR and IR spectra, the extraction mechanism of acetic acid dilute solution is studied. Two kinds of extraction mechanism, which are hydrogen bond complexing mechanism and ion salinization mechanism, are proposed.

1996-01-01

185

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

186

Acetic acid used for the elimination of Pseudomonas aeruginosa from burn and soft tissue wounds.  

Science.gov (United States)

Acetic acid was used topically at concentrations of between 0.5% and 5% to eliminate Pseudomonas aeruginosa from the burn wounds or soft tissue wounds of 16 patients. In-vitro studies indicated the susceptibility of P. aeruginosa to acetic acid; all strains exhibited a minimum inhibitory concentration of 2 per cent. P. aeruginosa was eliminated from the wounds of 14 of the 16 patients within two weeks of treatment. Acetic acid was shown to be an inexpensive and efficient agent for the elimination of P. aeruginosa from burn and soft tissue wounds. PMID:8355236

Sloss, J M; Cumberland, N; Milner, S M

1993-06-01

187

Oriented production of acetic acid in sludge anaerobic fermentation by methane-bacterium specific inhibitor  

UK PubMed Central (United Kingdom)

The present invention provides a method of directional acetic acid production in anaerobic sludge fermentation using methanogenic bacteria-specific inhibitors which belongs to the sludge recycling field. This invention prepares the methanogenic bacteria-specific inhibitor, 2-bromethylsulfonate sodium into solution of certain concentration and adds the solution into the pretreated sludge. When the concentration of 2-bromethylsulfonate sodium is 5-20 mmol/L and the initial pH is 6-8, the maxmium concentration of acetic acid can achieve 1.84g/L after 15-20 day's fermentation, which is more than five times of the yield of acetic acid under natural conditions. The addition of 2-bromethylsulfonate sodium into anaerobic digestion system will inhibit methanogens and facilitates the accumulation of organic acids, especially acetic acid.

CHEN JIAN LIU

188

Severe renal function impairment in adult patients acutely poisoned with concentrated acetic acid.  

UK PubMed Central (United Kingdom)

Acetic acid is a widely used organic acid with corrosive properties that depend on its concentration. If acetic acid is ingested in concentrations above 30 % it may severely damage the upper gastrointestinal tract and cause intravascular haemolysis, which can result in severe kidney and liver disorders and disseminated intravascular coagulation. In this retrospective study, we analysed acetic acid ingestion data collected at the University Clinic for Toxicology of Skopje, Macedonia from 1 January 2002 to 31 December 2011. The analysis included systemic complications, kidney damage, and the outcomes in particular. Over the ten years, 84 patients were reported at the Clinic to have ingested highly concentrated acetic acid. Twenty-eight developed kidney disorders, while the remaining 56 had no complications. Fatal outcome was reported for 11 patients, seven of whom had systemic complications and four severe gastrointestinal complications.

Chibishev A; Sikole A; Pereska Z; Chibisheva V; Simonovska N; Orovchanec N

2013-03-01

189

1-Methylpyrrolidine-2-acetic Acid is not a Precursor of Tropane Alkaloids.  

UK PubMed Central (United Kingdom)

1-Methylpyrrolidine-2-acetic acid and related compounds were studied as precursors in the biosynthesis of the tropane alkaloids in Erythroxylum coca and Datura innoxia. (R,S)-[1',2-(13)C2,2-(14)C,(15)N]-1-methylpyrrolidine-2- acid, (R,S)-[1',2'-(13)C2,1'-(14)C]-1-methylpyrrolidine-2-acetic acid, (R,S) [1',2'-(13)C2,1-(14)C]-1-methylpyrrolidine-2-acetate, and (R,S)-+2'-(14)C] methylpyrrolidine-2-acetic acid N-acetylcysteamine thioester were synthesized an intact plants by leaf-planting or hydroponic-feeding. Specific incorporation of compounds into ( - )-hyoscyamine, ( - )-scopolamine, ( - )-cocaine and the biosynthetically related cuscohygrine were very low. These results indicate that 1-methylpyrrolidine acid is not an efficient precursor of tropane alkaloids.

Huang MN; Abraham TW; Kim SH; Leete E

1996-02-01

190

1-Methylpyrrolidine-2-acetic Acid is not a Precursor of Tropane Alkaloids.  

Science.gov (United States)

1-Methylpyrrolidine-2-acetic acid and related compounds were studied as precursors in the biosynthesis of the tropane alkaloids in Erythroxylum coca and Datura innoxia. (R,S)-[1',2-(13)C2,2-(14)C,(15)N]-1-methylpyrrolidine-2- acid, (R,S)-[1',2'-(13)C2,1'-(14)C]-1-methylpyrrolidine-2-acetic acid, (R,S) [1',2'-(13)C2,1-(14)C]-1-methylpyrrolidine-2-acetate, and (R,S)-+2'-(14)C] methylpyrrolidine-2-acetic acid N-acetylcysteamine thioester were synthesized an intact plants by leaf-planting or hydroponic-feeding. Specific incorporation of compounds into ( - )-hyoscyamine, ( - )-scopolamine, ( - )-cocaine and the biosynthetically related cuscohygrine were very low. These results indicate that 1-methylpyrrolidine acid is not an efficient precursor of tropane alkaloids. PMID:8835455

Huang, M N; Abraham, T W; Kim, S H; Leete, E

1996-02-01

191

Beneficial effect of acetic acid vapor on management of carbon monoxide poisoning: clinical and experimental data  

Energy Technology Data Exchange (ETDEWEB)

The effects of accidental carbon monoxide poisoning, resulting primarily from the use of coal for heating and cooking, were observed in 30 patients. One group of patients was brought directly to the hospital and received acetic inhalation in addition to oxygen therapy. A second group of patients accidentally exposed to CO gas was managed at home by trained paramedical personnel who administered acetic acid inhalation therapy. In all human subjects poisoned with CO gas, acetic acid inhalation reduced the time in minutes to regain consciousness from a semicomatose state as compared with patients receiving no treatment or oxygen therapy alone. The optimal rate of acetic acid administration for reversal of the signs and symptoms of CO poisoning was three inhalations per minute at 2-min intervals. In vivo and in vitro experiments demonstrated additional effects of acetic acid in several species of CO poisoned animals: these included increases in red blood cell masses, shifting of the COHb dissociation curve to the right, and promotion of CO dissociation from Hb. Acetic acid also improved the respiration, carotid blood flow, and bile secretion rate in CO intoxicated animals. The data of this investigation advocate immediate acetic acid vapor inhalation therapy in victims accidentally poisoned with carbon monoxide.

Lee, P.H.; Kwon, S.P.; Kang, B.S.; Kang, D.H.; Lee, K.S.; Oh, H.K.; Lee, W.

1981-12-01

192

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

193

Indole-3-acetic acid and 2-(indol-3-ylmethyl)indol-3-yl acetic acid in the thermophilic archaebacterium Sulfolobus acidocaldarius.  

UK PubMed Central (United Kingdom)

Indole-3-acetic acid (IAA) and 2-(indol-3-ylmethyl)indol-3-yl acetic acid were identified in lipid extracts of Sulfolobus acidocaldarius; they occurred at concentrations of 0.57 and 0.59 mumol/g (dry weight), respectively. The amount of IAA found in these cells is more than a thousand times greater than that found in a typical extract of a plant in which IAA serves as a plant growth hormone. Neither of these compounds was detected in the other archaebacteria that were analyzed; these included Sulfolobus sulfataricus, Halobacterium salinarium, and several strains of methanogenic bacteria. This is the first report of the natural occurrence of 2-(indol-3-ylmethyl)indol-3-yl acetic acid.

White RH

1987-12-01

194

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 parameters viz., plant height, plant spread, number of primary shoots, secondary shoots and survival percentage. Maximum plant height (134.2 cm), plant spread (46.3 cm), primary shoots (6.3), secondary shoots (25) and survival percentage (94.72%) were recorded when the rose cuttings were applied with NAA at the rate of 50 mg L-1. Among the plant growth regulators, Naphthalene Acetic Acid (NAA) was found to be superior to indole-3-acetic acid (IAA) for its stronger effect regarding all parameters. The optimum level of Naphthalene Acetic Acid (NAA) was found in the range of 50 and 75 mg L-1, while no such conclusion could be drawn for indole-3-acetic acid (IAA) as all growth parameters were linearly increased up to the highest concentrations of IAA i.e., 100 mg L-1. Regarding growing media, the leaf mould appeared the best in terms of its positive effect on establishment of rose cuttings by giving the maximum plant height (125.1 cm), plant spread (37 cm), primary shoots (5.2), secondary shoots (19.48) and survival percentage (85.67%), followed by soil + leaf mould, while soil media was least effective.

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

2007-01-01

195

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

196

Adsorption of acetic acid at platinum and gold electrodes: a combined infrared spectroscopic and radiotracer study  

Energy Technology Data Exchange (ETDEWEB)

The potential-dependent specific adsorption of acetic acid and acetate at polycrystalline platinum- and gold-aqueous interfaces has been examined by potential-difference infrared spectroscopy (PDIRS) in conjunction with quantitative surface concentration measurements using the radiotracer technique. Both the infrared and radiotracer measurements utilize a similar thin-layer solution arrangement. Extensive adsorption of acetic acid occurs at both platinum and gold, which increases at more positive potentials and reaches a maximum at the onset of anodic oxide formation. The PDIR spectra contain several features identified with solution acetic acid in the 1200-1800-cm/sup -1/ region, including v/sub C==O/ and v/sub C-O/ bands at 1710 and 1280 cm/sup -1/, respectively, arising from adsorption-induced changes in the thin-layer solution composition as well as a single band, at 1415 and 1400 cm/sup -1/ on platinum and gold, restively, due to adsorbed acetic acid. The intensity of the former bands can by employed to evaluate the extent of adsorption as a function of potential; the results are in semiquantitative agreement with the surface concentration-potential data from radiotracer measurements. In view of the infrared spectra together with the observed absence of acetate adsorption, the most likely modes of acetic acid adsorption involve hydrogen bonding between the carbonyl oxygen and inner-layer water molecules, of by self-association to form dimers or chain structures

Corrigan, D.S.; Krauskopf, E.K.; Rice, L.M.; Wieckowski, A.; Weaver, M.J.

1988-03-24

197

Preparation and Characterization of Modified Cellulose Acetate Membrane to Remove Europium(III) and Cesium from Their Wastes  

International Nuclear Information System (INIS)

In this work, modified cellulose acetate based membranes were prepared by blending cellulose acetate (CA) with polyethylene glycol (PEG) and acrylamide (AAm) in different concentrations. Characterization of the prepared membranes such as swelling behavior and IR were investigated. Batch technique was used to investigate the removal of Eu(III) and Cs from their wastes. Effect of ph, contact time, monomer concentrations, temperature and adsorbed dose on the removal process was determined in the absence and presence of polymeric additives. The results showed good adsorption capacities of Eu(III) and Cs on the prepared modified cellulose acetate membrane compared to pure cellulose acetate. The adsorption capacity of Eu(llI) and Cs increases as a function of concentration of PEG and AAm. The percent removal of Eu(III) on CA, CNAAm and CAIPEG was 64, 82 and 98 %, respectively, while the percent removal of Cs on CA, CA/AAm and CA/PEG was 53, 78 and 89 %, respectively. Batch desorption and regeneration experiments revealed that 0.5 M HCl performed well in eluting Eu(III) and Cs and caused very low damage to the prepared membranes. Reuse of the prepared membrane after one sorption cycle resulted reduction in the sorption capacity in less than about 13% for Eu and 12% for Cs. This is suggesting that the prepared membrane is a multiple-use adsorbent. The adsorption isotherm behavior of the prepared membranes fit Langmuir isotherm.

2010-01-01

198

Preparation and characterization of modified cellulose acetate membrane to remove europium (III) and cesium from their wastes  

International Nuclear Information System (INIS)

In this work, modified cellulose acetate based membranes were prepared by blending cellulose acetate (CA) with polyethyleneglycol (PEG) and acrylamide (AAm) in various concentrations. Characterizations of the prepared membranes such as swelling behavior and IR were investigated. Batch technique were used to investigate the removal of Eu(III) and Cs from their wastes. Effect of pH, contact time, concentrations, temperature and adsorbent dosage on the removal process was determined in absence and presence of polymeric additives. The results showed good adsorption capacities of Eu(III) and Cs on modified cellulose acetate membrane compared to pure cellulose acetate. The adsorption capacity of Eu(III) and Cs increases as a function of concentration of PEG and AAm. The percent removal of Eu(III) on CA, CA/AAm and CA/PEG was 64, 82 and 98 respectively, while the percentage removal of Cs on CA, CA/AAm and CA/PEG was 53, 78 and 89 respectively. Batch desorption and regeneration experiments revealed that 0.5 M HCl performed well in eluting Eu(III) and Cs and caused very low damage to the prepared membranes. Reuse of the prepared membrane after one sorption cycle resulted in less than about 13% (for Eu), 12% (for Cs) reduction in the sorption capacity of the isotopes suggesting that the prepared membrane is a multiple-use adsorbent. The adsorption isotherm behavior of the prepared membranes fit Langmuir isotherm. (author)

2008-01-01

199

THE EFFECTS OF ANIMAL AGE AND ACETIC ACID CONCENTRATION ON PIGSKIN GELATIN CHARACTERISTICS  

Directory of Open Access Journals (Sweden)

Full Text Available This research was aimed to study the influence of animal age and concentration of the acetic acid solution on physical and chemical properties of pigskin gelatin. The experiment used Completely Randomized Design (CRD) with two factors. The first factor was animal age consisted of 3 levels (5, 7 and 9 months). The second factor was concentration of acetic acid solution consisted of 3 levels (2, 4 and 6 percents). The result showed that animal age had significant effect (P0.05) on the yields, gel strength, viscosity, protein content and pH value. It was concluded that pigskin gelatin from ages of 5, 7 and 9 months and acetic acid concentration of 2, 4 and 6% had similar characteristics to the commercial gelatin, but the optimum production of gelatin was combination of pigskin gelatin from 7 months and of 2% acetic acid.

M. Sompie; S. Triatmojo; A. Pertiwiningrum; Y. Pranoto

2012-01-01

200

The use of basic polymer sorbents for the recovery of acetic acid from dilute aqueous solution  

Energy Technology Data Exchange (ETDEWEB)

Measurements were made of preferential uptakes of acetic acid from aqueous solution onto basic polymer sorbents. Individual uptakes of water and acetic acid were measured as well. The sorption equilibria were interpreted through a chemical complexation model yielding sorption affinities and capacities for acetic acid. Basicity scales, such as pKa and Gutmann Donor Number (DN) based upon the monomeric functional group chemistry, were shown to explain the trends in sorption affinities. The use of different solvents to leach sorbed acetic acid from basic polymer sorbents was investigated as a means of regenerating the sorbents. It was found that regeneration can be improved by using solvents of high donicity. Aqueous ammonia proved to be effective for regenerating moderately strong base sorbents. 83 refs., 51 figs., 11 tabs.

Garcia, A.A.; King, C.J.

1988-01-01

 
 
 
 
201

The Syntheses of Some Novel (Naphthalen-1-yl-selenyl)acetic Acid Derivatives  

Directory of Open Access Journals (Sweden)

Full Text Available Some new (naphthalen-1-yl-selenyl)acetic acids derivatives 7a-d have been synthesized by two different methods, using naphthylselenols or naphthylselenocyanates. The structures of the products were investigated by spectroscopic methods.

Serkan Yavuz; Ali Dişli; Yılmaz Yıldırır; Lemi Türker

2005-01-01

202

Kinetic model for methanogenesis of acetic acid in a multireactor system  

Energy Technology Data Exchange (ETDEWEB)

Bioconversion of acetic acid to methane by a crude culture of methanogens in a continuous multireactor system was investigateed. Culture of methanogens was drawn from an active cow-dung digester (12 days) and was grown in a semisynthetic medium (pH 6.3, 37/sup 0/C) with acetic acid as the sole carbon source. The solubilities of CO/sub 2/, HCO/sub 3//sup -/ and CO/sub 3//sup 2 -/ increased with the rise in pH and exercised considerable influence on the gas composition. Various mechanisms for methanogenesis of acetic acid based on the available pathways were considered. Experimental data were compared with these mechansims, the best fit was determined, and the corresponding rate expression was identified. This mechanism predicted that, of the total methane produced, 72% comes from acetic acid directly and 28% via the CO/sub 2/ reduction route.

Bhadra, A.; Mukhopadhyay, S.N.; Ghose, T.K.

1984-01-01

203

Dehydration of acetic acid-water mixtures with near critical and supercritical fluid solvents  

Energy Technology Data Exchange (ETDEWEB)

Equilibrium tie lines and phase densities are presented for acetic acid-water mixtures with near critical propane at 361K and 52 bar. Experimental measurements were obtained with a static technique; the equilibrium phases were directly sampled with high-pressure liquid sample injection valves at the temperature and pressure of interest. The data obtained in this work indicate that near critical propane can be used to facilitate the production of glacial acetic acid from dilute acetic acid-water solutions. Both these experimental data and the authors earlier results for acetic acid-water mixtures with supercritical carbon dioxide have been used to test an equation of state which has recently been developed by Grenzheuser and Gmehling for systems which contain associating fluids. Results indicate that the equation's pure component parameters need to be refitted to represent the critical region more accurately.

McCully, M.A.; Mullins, J.C.; Thies, M.C.; Hartley, I.J.

1988-10-01

204

Hydrothermal synthesis of CuInSe2 nanoparticles in acetic acid  

Science.gov (United States)

The CuInSe2 nanoparticles for thin-film solar cells were successfully synthesized using a simple hydrothermal method with acetic acid as a mineralizer. The CuInSe2 nanoparticles with high purity were formed with acetic acid concentration of 5 M, reaction temperature of 200 °C, and reaction time of 12 h. The concentrations of acetic acid significantly affected the phase, morphology, and size of the prepared particles. The crystallinity and the particle size also increased as a function of the reaction temperature and the reaction time. Room-temperature Raman spectra shows that the single-phased of CuInSe2 nanoparticles were obtained via the hydrothermal synthesis with acetic acid. We proposed the one-step reaction mechanism for the CuInSe2 nanoparticles based on the X-ray diffraction and the scanning electron microscopy data.

Shim, Jang Bo; Kim, Chang Gyoun; Jeon, Dong Ju; Chung, Taek-Mo; An, Ki-Seok; Lee, Sun Suk; Lim, Jong Sun; Jeong, Seok Jong; Park, Bo Keun; Lee, Young Kuk

2013-06-01

205

2-(1H-Pyrazol-4-yl)acetic acids as CRTh2 antagonists.  

UK PubMed Central (United Kingdom)

High throughput screening identified the pyrazole-4-acetic acid substructure as CRTh2 receptor antagonists. Optimisation of the compounds uncovered a tight SAR but also identified some low nanomolar inhibitors.

Andrés M; Bravo M; Buil MA; Calbet M; Castro J; Domènech T; Eichhorn P; Ferrer M; Gómez E; Lehner MD; Moreno I; Roberts RS; Sevilla S

2013-06-01

206

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

International Nuclear Information System (INIS)

[en] 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

1975-01-01

207

Recovery of acetic acid from dilute aqueous solutions using catalytic dehydrative esterification with ethanol.  

UK PubMed Central (United Kingdom)

We have developed a direct esterification of aqueous acetic acid with ethanol (molar ratio=1:1) catalyzed by polystyrene-supported or homogeneous sulfonic acids toward the recovery of acetic acid from wastewater in chemical plants. The equilibrium yield was significantly increased by the addition of toluene, which had a high ability to extract ethyl acetate from the aqueous phase. It was shown that low-loading and alkylated polystyrene-supported sulfonic acid efficiently accelerated the reaction. These results suggest that the construction of hydrophobic reaction environments in water was critical in improving the chemical yield. Addition of inorganic salts was also effective for the reaction under not only biphasic conditions (toluene-water) but also toluene-free conditions, because the mutual solubility of ethyl acetate and water was suppressed by the salting-out effect. Among the tested salts, CaCl(2) was found to be the most suitable for this reaction system.

Yagyu D; Ohishi T; Igarashi T; Okumura Y; Nakajo T; Mori Y; Kobayashi S

2013-03-01

208

75 FR 40736 - Acetic Acid; Exemption from the Requirement of a Tolerance  

Science.gov (United States)

...out in the mitochondria of the cells of plants and animals including...acetic acid destroys or damages the cell membrane of the plants which causes rapid...Some Microbials, Antioxidants, Emulsifiers, Stabilizers,...

2010-07-14

209

The antimicrobial effect of acetic acid--an alternative to common local antiseptics?  

UK PubMed Central (United Kingdom)

Acetic acid has been commonly used in medicine for more than 6000 years for the disinfection of wounds and especially as an antiseptic agent in the treatment and prophylaxis of the plague. The main goal of this study was to prove the suitability of acetic acid, in low concentration of 3%, as a local antiseptic agent, especially for use in salvage procedures in problematic infections caused by organisms such as Proteus vulgaris, Acinetobacter baumannii or Pseudomonas aeruginosa. This study was designed to compare the in vitro antimicrobial effect of acetic acid with those of common local antiseptics such as povidone-iodine 11% (Betaisodona), polyhexanide 0.04% (Lavasept), mafenide 5% and chlohexidine gluconate 1.5% cetrimide 15% (Hibicet). Former studies suggest the bactericidal effect of acetic acid, but these data are very heterogeneous; therefore, a standardised in vitro study was conducted. To cover the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacterial strains were tested: Escherichia coli, P. vulgaris, P. aeruginosa, A. baumannii, Enterococcus faecalis, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA) and beta-haemolytic Streptococcus group A and B. The tests showed excellent bactericidal effect of acetic acid, particularly with problematic Gram-negative bacteria such as P. vulgaris, P. aeruginosa and A. baumannii. The microbiological spectrum of acetic acid is wide, even when tested at a low concentration of 3%. In comparison to our currently used antiseptic solutions, it showed similar - in some bacteria, even better - bactericidal properties. An evaluation of the clinical value of topical application of acetic acid is currently underway. It can be concluded that acetic acid in a concentration of 3% has excellent bactericidal effect and, therefore, seems to be suitable as a local antiseptic agent, but further clinical studies are necessary.

Ryssel H; Kloeters O; Germann G; Schäfer T; Wiedemann G; Oehlbauer M

2009-08-01

210

The antimicrobial effect of acetic acid--an alternative to common local antiseptics?  

Science.gov (United States)

Acetic acid has been commonly used in medicine for more than 6000 years for the disinfection of wounds and especially as an antiseptic agent in the treatment and prophylaxis of the plague. The main goal of this study was to prove the suitability of acetic acid, in low concentration of 3%, as a local antiseptic agent, especially for use in salvage procedures in problematic infections caused by organisms such as Proteus vulgaris, Acinetobacter baumannii or Pseudomonas aeruginosa. This study was designed to compare the in vitro antimicrobial effect of acetic acid with those of common local antiseptics such as povidone-iodine 11% (Betaisodona), polyhexanide 0.04% (Lavasept), mafenide 5% and chlohexidine gluconate 1.5% cetrimide 15% (Hibicet). Former studies suggest the bactericidal effect of acetic acid, but these data are very heterogeneous; therefore, a standardised in vitro study was conducted. To cover the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacterial strains were tested: Escherichia coli, P. vulgaris, P. aeruginosa, A. baumannii, Enterococcus faecalis, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA) and beta-haemolytic Streptococcus group A and B. The tests showed excellent bactericidal effect of acetic acid, particularly with problematic Gram-negative bacteria such as P. vulgaris, P. aeruginosa and A. baumannii. The microbiological spectrum of acetic acid is wide, even when tested at a low concentration of 3%. In comparison to our currently used antiseptic solutions, it showed similar - in some bacteria, even better - bactericidal properties. An evaluation of the clinical value of topical application of acetic acid is currently underway. It can be concluded that acetic acid in a concentration of 3% has excellent bactericidal effect and, therefore, seems to be suitable as a local antiseptic agent, but further clinical studies are necessary. PMID:19286325

Ryssel, H; Kloeters, O; Germann, G; Schäfer, Th; Wiedemann, G; Oehlbauer, M

2009-03-16

211

Asaia lannaensis sp. nov., a new acetic acid bacterium in the Alphaproteobacteria.  

UK PubMed Central (United Kingdom)

Asaia lannaensis sp. nov. was described for two strains isolated from flowers of the spider lily collected in Chiang Mai, Thailand. The isolates produced acetic acid from ethanol on ethanol/calcium carbonate agar, differing from the type strains of Asaia bogorensis, Asaia siamensis, and Asaia krungthepensis, but did not grow in the presence of 0.35% acetic acid (v/v). The new species is the fourth of the genus Asaia, the family Acetobacteraceae.

Malimas T; Yukphan P; Takahashi M; Kaneyasu M; Potacharoen W; Tanasupawat S; Nakagawa Y; Tanticharoen M; Yamada Y

2008-03-01

212

Asaia lannaensis sp. nov., a new acetic acid bacterium in the Alphaproteobacteria.  

Science.gov (United States)

Asaia lannaensis sp. nov. was described for two strains isolated from flowers of the spider lily collected in Chiang Mai, Thailand. The isolates produced acetic acid from ethanol on ethanol/calcium carbonate agar, differing from the type strains of Asaia bogorensis, Asaia siamensis, and Asaia krungthepensis, but did not grow in the presence of 0.35% acetic acid (v/v). The new species is the fourth of the genus Asaia, the family Acetobacteraceae. PMID:18323663

Malimas, Taweesak; Yukphan, Pattaraporn; Takahashi, Mai; Kaneyasu, Mika; Potacharoen, Wanchern; Tanasupawat, Somboon; Nakagawa, Yasuyoshi; Tanticharoen, Morakot; Yamada, Yuzo

2008-03-07

213

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

2010-01-01

214

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.

Youssef A. Attia; Abdul E. Abd El-Hamid; Hany F. Ellakany; Fulvia Bovera; Mohammed A. Al-Harthi; Sharehan A. Ghazaly

2013-01-01

215

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

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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; Y. Du; C. Li; S. Zhu; Y. Qiu; J. Jiang

2011-01-01

216

Isolation of a strain of Clostridium thermoaceticum capable of growth and acetic acid production at pH 4. 5  

Energy Technology Data Exchange (ETDEWEB)

Using a series of pH controlled batch fermentations operated in a fed-batch mode and adaptation and selection techniques where pH and acetic acid provided the selective pressures, we isolated a culture of Clostridium thermoaceticum that can grow and produce acetic acid at pH 4.5. At pH 4.5 the fastest mass doubling time was 36 h, and the highest acetic acid concentration reached was 4.5 g/liter. Generally, as the pH was decreased from 6.0 and the initial acetic acid concentration increased, the mass doubling time increased, and the final acetic acid concentration decreased. These observations can be explained in terms of inhibition by the free acetic acid concentration at a given pH, relative to the total acetic acid concentration (free acid plus acetate ion). We have thus reached one of the criteria determined by us to be required for an economically viable fermentation acetic acid process, i.e., pH 4.5. A second requirement for a mass doubling time of about 7 h (0.1/h dilution rate) can probably be reached by selection in continuous culture. The final requirement for an acetic acid concentration of 50 g/liter will be the most difficult to achieve in view of the organism's sensitivity to low concentrations of free acetic acid. (Refs. 4).

Schwartz, R.D.; Keller, F.A. Jr.

1982-01-01

217

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

Energy Technology Data Exchange (ETDEWEB)

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/sub 2/, with the stoichiometry obtained for conversion approximating that predicted from the following reaction: 4CO + 2H/sub 2/O ..-->.. CH/sub 3/CO/sub 2/H + 2CO/sub 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. /sup 14/CO was incorporated, with equal distribution between the carboxyl and methyl carbons of acetic acid when the initial cultivation gas phase was 100% CO whereas /sup 14/CO/sub 2/ preferentially entered the carboxyl carbon when the initial gas phase was 100% CO/sub 2/. Significantly, in the presence of saturating levels of CO, /sup 14/CO/sub 2/ preferentially entered the methyl carbon, whereas saturating levels of CO/sub 2/ yielded /sup 14/CO-derived labeling predominantly in the carboxyl carbon. These findings are discussed in relation to the path of carbon flow to acetic acid.

Martin, D.R.; Misra, A.; Drake, H.L.

1985-06-01

218

Improved Processes to Remove Naphthenic Acids  

Energy Technology Data Exchange (ETDEWEB)

In the past three years, we followed the work plan as we suggested in the proposal and made every efforts to fulfill the project objectives. Based on our large amount of creative and productive work, including both of experimental and theoretic aspects, we received important technical breakthrough on naphthenic acid removal process and obtained deep insight on catalytic decarboxylation chemistry. In detail, we established an integrated methodology to serve for all of the experimental and theoretical work. Our experimental investigation results in discovery of four type effective catalysts to the reaction of decarboxylation of model carboxylic acid compounds. The adsorption experiment revealed the effectiveness of several solid materials to naphthenic acid adsorption and acidity reduction of crude oil, which can be either natural minerals or synthesized materials. The test with crude oil also received promising results, which can be potentially developed into a practical process for oil industry. The theoretical work predicted several possible catalytic decarboxylation mechanisms that would govern the decarboxylation pathways depending on the type of catalysts being used. The calculation for reaction activation energy was in good agreement with our experimental measurements.

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

2005-12-09

219

Acetic acid modulates spike rate and spike latency to salt in peripheral gustatory neurons of rats.  

UK PubMed Central (United Kingdom)

Sour and salt taste interactions are not well understood in the peripheral gustatory system. Therefore, we investigated the interaction of acetic acid and NaCl on taste processing by rat chorda tympani neurons. We recorded multi-unit responses from the severed chorda tympani nerve (CT) and single-cell responses from intact narrowly tuned and broadly tuned salt-sensitive neurons in the geniculate ganglion simultaneously with stimulus-evoked summated potentials to signal when the stimulus contacted the lingual epithelium. Artificial saliva served as the rinse and solvent for all stimuli [0.3 M NH(4)Cl, 0.5 M sucrose, 0.1 M NaCl, 0.01 M citric acid, 0.02 M quinine hydrochloride (QHCl), 0.1 M KCl, 0.003-0.1 M acetic acid, and 0.003-0.1 M acetic acid mixed with 0.1 M NaCl]. We used benzamil to assess NaCl responses mediated by the epithelial sodium channel (ENaC). The CT nerve responses to acetic acid/NaCl mixtures were less than those predicted by summing the component responses. Single-unit analyses revealed that acetic acid activated acid-generalist neurons exclusively in a concentration-dependent manner: increasing acid concentration increased response frequency and decreased response latency in a parallel fashion. Acetic acid suppressed NaCl responses in ENaC-dependent NaCl-specialist neurons, whereas acetic acid-NaCl mixtures were additive in acid-generalist neurons. These data suggest that acetic acid attenuates sodium responses in ENaC-expressing-taste cells in contact with NaCl-specialist neurons, whereas acetic acid-NaCl mixtures activate distinct receptor/cellular mechanisms on taste cells in contact with acid-generalist neurons. We speculate that NaCl-specialist neurons are in contact with type I cells, whereas acid-generalist neurons are in contact with type III cells in fungiform taste buds.

Breza JM; Contreras RJ

2012-11-01

220

Genome shuffling to improve fermentation properties of acetic acid bacterium by the improvement of ethanol tolerance  

UK PubMed Central (United Kingdom)

Whole?cell biocatalysts are commonly limited by low tolerance of extreme process conditions such as alcoholic strength, temperature, pH and concentration of solute. Here, we describe the use of genome shuffling to improve the ethanol tolerance of acetic acid bacterium, which is a poorly characterised industrial strain. The best strain A3?11 was constructed and selected after three rounds of shuffling from the wild?type strain of acetic acid bacterium. A3?11 could grow in liquid medium with 13% ethanol. During the vinegar fermentation, the organic acid components produced were distinctly improved by A3?11. It was found that the content of acetic acid was twice as much as the control. Furthermore, the concentration of tartaric acid was 4.04?fold more than the control. Notably, A3?11 increased in butanedioic acid production by up to 71.73% compared with the control.

Wei K; Cao X; Li X; Wang C; Hou L

2012-10-01

 
 
 
 
221

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

Directory of Open Access Journals (Sweden)

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; Grubi? Goran; Glamo?i? Dragan M.

2004-01-01

222

Nutrient salts promote light-induced degradation of indole-3-acetic Acid in tissue culture media.  

UK PubMed Central (United Kingdom)

The disappearance of indole-3-acetic acid (IAA) from cell-free liquid culture medium was followed in response to nutrient salts found in Murashige-Skoog salt base, light, and pH range of 4 to 7. The loss of IAA was accelerated by light or Murashige-Skoog salts. However, the combination of both light and Murashige-Skoog salts acted synergistically to catalyze the destruction of over 80% of the original IAA within 7 days of continuous incubation. Under these same conditions, the loss of IAA was decreased to approximately 50% by adjusting the initial pH of the medium to 7. Iron was identified as the single major contributor to light-catalyzed destruction of IAA. Removal of nitrates, which represented 87% of the molar salt composition, also reduced the light-catalyzed loss of IAA. Treatments that protected IAA from degradation, such as darkness or removal of iron from the medium, suppressed the growth of muskmelon (Cucumis melo. Naud., var. reticulatus) callus tissue cultured for 30 days. Treatments in the light that rapidly degraded IAA resulted in maximum growth. Consequently, the brief exposure to IAA prior to degradation was apparently sufficient to initiate physiological changes required for growth. Possible approaches to the preservation of IAA during incubation are discussed.

Dunlap JR; Robacker KM

1988-10-01

223

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

UK PubMed Central (United Kingdom)

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.

Michniak BB; Player MR; Sowell JW Sr

1996-02-01

224

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

225

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

Directory of Open Access Journals (Sweden)

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; M. PANDEESWARAN; D. S. BHUVANESHWARI; K. P. ELANGO

2006-01-01

226

Performance of dairy cows fed high levels of acetic acid or ethanol.  

UK PubMed Central (United Kingdom)

Ethanol and acetic acid are common end products from silages. The main objective of this study was to determine whether high concentrations of ethanol or acetic acid in total mixed ration would affect performance in dairy cows. Thirty mid-lactation Holstein cows were grouped in 10 blocks and fed one of the following diets for 7 wk: (1) control (33% Bermuda hay + 67% concentrates), (2) ethanol [control diet + 5% ethanol, dry matter (DM) basis], or (3) acetic acid (control diet + 5% acetic acid, DM basis). Ethanol and acetic acid were diluted in water (1:2) and sprayed onto total mixed rations twice daily before feeding. An equal amount of water was mixed with the control ration. To adapt animals to these treatments, cows were fed only half of the treatment dose during the first week of study. Cows fed ethanol yielded more milk (37.9 kg/d) than those fed the control (35.8 kg/d) or acetic acid (35.3 kg/d) diets, mainly due to the higher DM intake (DMI; 23.7, 22.2, and 21.6 kg/d, respectively). The significant diet × week interaction for DMI, mainly during wk 2 and 3 (when acetic acid reached the full dose), was related to the decrease in DMI observed for the acetic acid treatment. There was a diet × week interaction in excretion of milk energy per DMI during wk 2 and 3, due to cows fed acetic acid sustained milk yield despite lower DMI. Energy efficiency was similar across diets. Blood metabolites (glucose, insulin, nonesterified fatty acids, ethanol, and ?-glutamyl transferase activity) and sensory characteristics of milk were not affected by these treatments. Animal performance suggested similar energy value for the diet containing ethanol compared with other diets. Rumen conversion of ethanol to acetate and a concomitant increase in methane production might be a plausible explanation for the deviation of the predicted energy value based on the heat of combustion. Therefore, the loss of volatile compounds during the drying process in the laboratory should be considered when calculating energy content of fermented feedstuffs.

Daniel JL; Amaral RC; Sá Neto A; Cabezas-Garcia EH; Bispo AW; Zopollatto M; Cardoso TL; Spoto MH; Santos FA; Nussio LG

2013-01-01

227

Combined sorption/transport of sodium dodecyl sulfate and hydrochloric acid in a blend of cellulose acetate butyrate with cellulose acetate hydrogen phthalate  

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The transport of hydrochloric acid (0.001-0.1 M) and sodium dodecyl sulfate (0.001-0.1 M) has been measured through a membrane consisting of a blend of cellulose acetate butyrate and cellulose acetate hydrogen phthalate. The cellulose derivative blend is suggested to suffer an alteration in the degr...

Valente, Artur J. M.; Burrows, Hugh D.; Polishchuk, Alexandre Ya.; Miguel, Maria G.; Lobo, Victor M. M.

228

Production of carrier-free /sup 18/F-labeled acetic acid via a recoil labeling method  

Energy Technology Data Exchange (ETDEWEB)

Via recoil activation, carrier-free /sup 18/F-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, /sup 18/F-labeled acetic acid could be found. This system is assumed to be more applicable for the production of other /sup 18/F-labeled carboxylic acids. Under optimized irradiation conditions we expect to produce some mCi of labeled monofluoroacetic acid.

Donnerhack, A.; Sattler, E.L.

1980-06-01

229

Acetic acid compared with i-scan imaging for detecting Barrett's esophagus: a randomized, comparative trial.  

UK PubMed Central (United Kingdom)

BACKGROUND: Traditional surveillance in patients with Barrett's esophagus (BE) has relied on random biopsies. Targeted biopsies that use advanced imaging modalities may significantly improve detection of specialized columnar epithelium (SCE). OBJECTIVE: We compared the efficacy of targeted biopsies that used i-scan or acetic acid to random biopsies in the detection of SCE. DESIGN: Patients with visible columnar lined epithelium or known BE were randomized at a 1:1 ratio to undergo acetic acid application or i-scan with targeted biopsies. SETTING: Targeted biopsies were performed based on surface architecture according to the Guelrud classification followed by 4-quadrant biopsies. PATIENTS: A total of 95 patients were randomized. INTERVENTION: A total of 46 patients underwent acetic acid staining, and 49 underwent i-scan imaging. Random biopsies were performed in 86 patients. MAIN OUTCOME MEASUREMENTS: The primary outcome was the yield of SCE as confirmed by histologic assessment. RESULTS: The diagnostic yield for SCE was significantly higher with targeted biopsies than with random biopsies in both groups combined (63% vs 24%; P = .0001). The yield of targeted biopsies was significantly greater with both i-scan (66% vs 21%; P = .009) and acetic acid (57% vs 26%; P = .012) technologies and did not differ between these groups. The accuracy for predicting SCE was 96% (k = .92) for i-scan and 86% (k = .70) for acetic acid analysis. LIMITATIONS: No dysplastic lesions were found. CONCLUSION: The i-scan or acetic acid-guided biopsies have a significantly higher diagnostic yield for identifying SCE, with significantly fewer biopsies, as compared with a protocol of random biopsies. Acetic acid and i-scan showed comparable results diagnosing SCE in our study. (Clinical trial registration number: NCT01442506.).

Hoffman A; Korczynski O; Tresch A; Hansen T; Rahman F; Goetz M; Murthy S; Galle PR; Kiesslich R

2013-08-01

230

Radiofrequency Thermal Ablation: Increase in Lesion Diameter with Continuous Acetic Acid Infusion  

International Nuclear Information System (INIS)

Purpose. To evaluate the influence of continuous infusion of acetic acid 50% during radiofrequency ablation (RFA) on the size of the thermal lesion produced. Methods. Radiofrequency (RF) was applied to excised bovine liver by using an expandable needle electrode with 10 retractable tines (LeVeen Needle Electrode, RadioTherapeutics, Sunnyvale, CA) connected to a commercially available RF generator (RF 2000, RadioTherapeutics, Sunnyvale, CA). Experiments were performed using three different treatment modalities: RF only (n = 15), RF with continuous saline 0.9% infusion (n = 15), and RF with continuous acetic acid 50% infusion (n = 15). RF duration, power output, tissue impedance, and time to a rapid rise in impedance were recorded. The ablated lesions were evaluated both macroscopically and histologically. Results. The ablated lesions appeared as spherical or ellipsoid, well-demarcated pale areas with a surrounding brown rim with both RF only and RF plus saline 0.9% infusion. In contrast, thermolesions generated with RF in combination with acetic acid 50% infusion were irregular in shape and the central portion was jelly-like. Mean diameter of the coagulation necrosis was 22.3 ± 2.1 mm (RF only), 29.2 ± 4.8 mm (RF + saline 0.9%) and 30.7 ± 5.7 mm (RF + acetic acid 50%), with a significant increase in the RF plus saline 0.9% and RF plus acetic acid 50% groups compared with RF alone. Time to a rapid rise in impedance was significantly prolonged in the RF plus saline 0.9% and RF plus acetic acid 50% groups compared with RF alone. Conclusions. A combination of RF plus acetic acid 50% infusion is able to generate larger thermolesions than RF only or RF combined with saline 0.9% infusion.

2005-01-01

231

Laboratory Studies of the Tropospheric Loss Processes for Acetic and Peracetic Acid  

Science.gov (United States)

Organic acids are ubiquitous components of tropospheric air and contribute to acid precipitation, particularly in remote regions. These species are present in the troposphere as the result of direct emissions from anthropogenic and biogenic sources, and as the result of photochemical processing of hydrocarbons. Production of organic acids can occur following ozonolysis of unsaturated hydrocarbons, while both organic acids and peroxyacids are formed from the reactions of HO2 with acylperoxy radicals. For example, both acetic and peracetic acid are known products of the reaction of HO2 with acetylperoxy radicals. In this paper, data relevant to the gas-phase tropospheric destruction of both acetic and peracetic acid are reported, including studies of their UV absorption spectra and of their rate coefficients for reaction with OH radicals. The data, the first of their kind for peracetic acid, show that the gas-phase lifetime of this species will be on the order of 10 days, with OH reaction occurring more rapidly than photolysis. Data on the rate coefficient for reaction of OH with acetic acid appear to resolve some conflicting data in the previous literature, and show 1) that reaction of OH with the acetic acid dimer is slow compared to the monomer and 2) that the rate coefficient possesses a negative temperature dependence near room temperature.

Orlando, J. J.; Tyndall, G. S.

2002-12-01

232

Simultaneous removal of ethyl acetate and toluene in air streams using compost-based biofilters.  

UK PubMed Central (United Kingdom)

Biofitration was successfully applied to treat air streams containing a mixture of ethyl acetate and toluene. The experiment was performed by two identical bench-scale biofilters, which were acclimated by ethyl acetate and toluene, respectively. During a 3 month steady-state performance, the two biofilters showed equivalent elimination capacity (EC) for toluene (50 g/m(3) bed/h of pure toluene). However, the biofilter acclimated with ethyl acetate showed a much higher EC for ethyl acetate (400 g/m(3) bed/h of pure ethyl acetate) than that acclimated with toluene (250 g/m(3) bed/h). The concurrent biofiltration of toluene was inhibited by the presence of ethyl acetate. The results also showed that more nitrogen and phosphorus were consumed in the process of the biofiltration of toluene compared with the treatment of ethyl acetate. After the 3 month experiment, the pH of the media treating ethyl acetate dropped from 6.71 to 5.50, whereas the pH of the media treating toluene increased from 6.71 to 7.08.

Liu Y; Quan X; Sun Y; Chen J; Xue D; Chung JS

2002-11-01

233

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

234

Catalyst for synthesizing acetonitrile by using acetic acid and ammonia and manufacturing method thereof  

UK PubMed Central (United Kingdom)

The invention relates to the field of chemical catalyst preparation, and discloses a catalyst for synthesizing acetonitrile by using acetic acid and ammonia and a manufacturing method thereof. The catalyst comprises the following substances in percentage by weight: 85 to 90 percent of gamma-Al2O3, 1 to 5 percent of K2MoO4 or H3PMo12O4, 1 to 3 percent of KNO3, 3 to 8 percent of solid acid and 2 to 6 percent of NaSiO3. The catalyst is prepared by the steps of mixing and stirring, curing, granulating, roasting, cooling and the like. Because the catalyst is adopted in the process of synthesizing the acetonitrile by using the acetic acid and the ammonia, the reaction temperature is reduced, the conversion rate of the acetic acid is improved, the selectivity of the acetonitrile is improved and the economic benefit is improved.

CHUANBI LI; YANWEI LI; YUN SHAO; YUEHONG WU; WEI ZHANG

235

Modeling of yeast Brettanomyces bruxellensis growth at different acetic acid concentrations under aerobic and anaerobic conditions.  

UK PubMed Central (United Kingdom)

Glucose utilization by Brettanomyces bruxellensis at different acetic acid concentrations under aerobic and anaerobic conditions was investigated. The presence of the organic acid disturbs the growth and fermentative activity of the yeast when its concentration exceeds 2 g l(-1). A mathematical model is proposed for the kinetic behavior analysis of yeast growing in batch culture. A Matlab algorithm was used for estimation of model parameters, whose confidence intervals were also calculated at a 0.95 probability level using a t-Student distribution for f degrees of freedom. The model successfully simulated the batch kinetics observed at different concentrations of acetic acid under both oxygen conditions.

Yahara GA; Javier MA; Tulio MJ; Javier GR; Guadalupe AU

2007-11-01

236

The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii.  

UK PubMed Central (United Kingdom)

Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13)C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13)C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2), C(3) and C(4). The incorporation of [U-(14)C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production.

Rodrigues F; Sousa MJ; Ludovico P; Santos H; Côrte-Real M; Leão C

2012-01-01

237

The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii.  

Science.gov (United States)

Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13)C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13)C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2), C(3) and C(4). The incorporation of [U-(14)C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production. PMID:23285028

Rodrigues, Fernando; Sousa, Maria João; Ludovico, Paula; Santos, Helena; Côrte-Real, Manuela; Leão, Cecília

2012-12-28

238

Acetalization of hexanal with 2-ethyl hexanol catalyzed by solid acids  

Energy Technology Data Exchange (ETDEWEB)

The catalyst activity of solid acids such as niobium phosphate and Amberlyst 35, an ion exchange resin, was evaluated in the acetalization of hexanal with 2-ethyl-hexanol. The catalyst loading and the reaction temperature were evaluated in the hexanal conversions. The possibility of recycling niobium phosphate was also studied, showing that it was possible to reuse this catalyst without significant loss in its catalytic activity. The yield in acetal was above 90% under mild conditions. (author)

Barros, Alessandro O.; Faisca, Aline T.; Lachter, Elizabeth R.; Nascimento, Regina S.V.; San Gil, Rosane A.S., E-mail: lachter@iq.ufrj.b [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica

2011-07-01

239

Acetalization of hexanal with 2-ethyl hexanol catalyzed by solid acids  

International Nuclear Information System (INIS)

The catalyst activity of solid acids such as niobium phosphate and Amberlyst 35, an ion exchange resin, was evaluated in the acetalization of hexanal with 2-ethyl-hexanol. The catalyst loading and the reaction temperature were evaluated in the hexanal conversions. The possibility of recycling niobium phosphate was also studied, showing that it was possible to reuse this catalyst without significant loss in its catalytic activity. The yield in acetal was above 90% under mild conditions. (author)

2011-01-01

240

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 l?1) and recombinant protein (5.5 g l?1) concentrations obtained were increased by up to 37 and 20%, respectively.

Wong, M.; Woodley, John

2010-01-01

 
 
 
 
241

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

UK PubMed Central (United Kingdom)

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 cm(2) 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 NH(4)OH 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 l(-1)) and recombinant protein (5.5 g l(-1)) concentrations obtained were increased by up to 37 and 20%, respectively.

Wong M; Woodley JM; Lye GJ

2010-08-01

242

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

Science.gov (United States)

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 cm(2) 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 NH(4)OH 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 l(-1)) and recombinant protein (5.5 g l(-1)) concentrations obtained were increased by up to 37 and 20%, respectively. PMID:20383737

Wong, Michael; Woodley, John M; Lye, Gary J

2010-04-11

243

Studies on trace metal redistribution during extraction of model soils by acetic acid/sodium acetate  

Energy Technology Data Exchange (ETDEWEB)

A number of model soils synthesized with various known amounts of natural minerals and humic acid were employed to study copper and lead redistribution during extraction by 1 M HOAc/NaOAc. The adsorption intensities of the individual constituent phases were measured from adsorption isotherms, and the redistribution behavior was studied by the standard additions method. Humic acid and pyrolusite were found to exhibit the highest binding affinity for Cu and Pb, respectively, and their relative importance relies upon both their binding ability and their abundance. In view of the diverse compositions and various competing reactions involved, it is recommended that redistribution behavior will vary widely among both natural soil systems and given methods.

Shan Xiao-quan; Tu Qiang; Qian Jin [Research Center for Eco-Environment Sciences, Beijing (China)

1994-12-31

244

Simulation of the radiation-chemical transformations of acetic acid in aqueous solutions  

International Nuclear Information System (INIS)

A general model for the radiolysis of acetic acid and its aqueous solutions is proposed. The model adequately describes experimental data on the degradation of the acid and the formation of gases (H2, CO2, and CH4) in aqueous solutions at various pH values

2007-01-01

245

Asaia bogorensis gen. nov., sp. nov., an unusual acetic acid bacterium in the alpha-Proteobacteria.  

UK PubMed Central (United Kingdom)

Eight Gram-negative, aerobic, rod-shaped and peritrichously flagellated strains were isolated from flowers of the orchid tree (Bauhinia purpurea) and of plumbago (Plumbago auriculata), and from fermented glutinous rice, all collected in Indonesia. The enrichment culture approach for acetic acid bacteria was employed, involving use of sorbitol medium at pH 3.5. All isolates grew well at pH 3.0 and 30 degrees C. They did not oxidize ethanol to acetic acid except for one strain that oxidized ethanol weakly, and 0.35% acetic acid inhibited their growth completely. However, they oxidized acetate and lactate to carbon dioxide and water. The isolates grew well on mannitol agar and on glutamate agar, and assimilated ammonium sulfate for growth on vitamin-free glucose medium. The isolates produced acid from D-glucose, D-fructose, L-sorbose, dulcitol and glycerol. The quinone system was Q-10. DNA base composition ranged from 59.3 to 61.0 mol% G + C. Studies of DNA relatedness showed that the isolates constitute a single species. Phylogenetic analysis based on their 16S rRNA gene sequences indicated that the isolates are located in the acetic acid bacteria lineage, but distant from the genera Acetobacter, Gluconobacter, Acidomonas and Gluconacetobacter. On the basis of the above characteristics, the name Asaia bogorensis gen. nov., sp. nov. is proposed for these isolates. The type strain is isolate 71T (= NRIC 0311T = JCM 10569T).

Yamada Y; Katsura K; Kawasaki H; Widyastuti Y; Saono S; Seki T; Uchimura T; Komagata K

2000-03-01

246

Asaia bogorensis gen. nov., sp. nov., an unusual acetic acid bacterium in the alpha-Proteobacteria.  

Science.gov (United States)

Eight Gram-negative, aerobic, rod-shaped and peritrichously flagellated strains were isolated from flowers of the orchid tree (Bauhinia purpurea) and of plumbago (Plumbago auriculata), and from fermented glutinous rice, all collected in Indonesia. The enrichment culture approach for acetic acid bacteria was employed, involving use of sorbitol medium at pH 3.5. All isolates grew well at pH 3.0 and 30 degrees C. They did not oxidize ethanol to acetic acid except for one strain that oxidized ethanol weakly, and 0.35% acetic acid inhibited their growth completely. However, they oxidized acetate and lactate to carbon dioxide and water. The isolates grew well on mannitol agar and on glutamate agar, and assimilated ammonium sulfate for growth on vitamin-free glucose medium. The isolates produced acid from D-glucose, D-fructose, L-sorbose, dulcitol and glycerol. The quinone system was Q-10. DNA base composition ranged from 59.3 to 61.0 mol% G + C. Studies of DNA relatedness showed that the isolates constitute a single species. Phylogenetic analysis based on their 16S rRNA gene sequences indicated that the isolates are located in the acetic acid bacteria lineage, but distant from the genera Acetobacter, Gluconobacter, Acidomonas and Gluconacetobacter. On the basis of the above characteristics, the name Asaia bogorensis gen. nov., sp. nov. is proposed for these isolates. The type strain is isolate 71T (= NRIC 0311T = JCM 10569T). PMID:10758893

Yamada, Y; Katsura, K; Kawasaki, H; Widyastuti, Y; Saono, S; Seki, T; Uchimura, T; Komagata, K

2000-03-01

247

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

248

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

Energy Technology Data Exchange (ETDEWEB)

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

249

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

International Nuclear Information System (INIS)

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- and 200 ppm Na+. Of key interest was the impact of Cl- 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- 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.

2003-01-01

250

Impact of acetic acid concentration of fermented liquid feed on growth performance of piglets  

DEFF Research Database (Denmark)

Feeding fermented liquid feed (FLF) to pigs has proven to benefit gastrointestinal health of the animals. However, growth performance data of piglets and growing pigs fed FLF are variable and often a lower feed intake compared to feeding non-FLF or dry feed has been observed. Accumulation of microbial metabolites, namely acetic acid, possibly in combination with low feed pH, has been suggested to be determinant in reducing feed intake by impairing palatability. However, this hypothesis has never been investigated. A study was carried out to determine the impact of increasing levels of acetic acid in FLF on feed intake of weaners. Three experimental FLF diets were prepared to contain varying levels of acetic acid (30, 60, and 120 mM). Twenty piglets per treatment, weaned at 4 weeks of age and housed individually, were fed the experimental diets during six weeks starting at weaning. Feed intake and body weight were registered weekly. The results showed that high acetic acid concentration in FLF, accompanied by a slight lower pH level, tended to decrease feed intake without affecting body weight gain. This discrepancy could partly be explained by the difficulty in measuring accurately feed intake on dry matter basis when feeding liquid feed to pigs. In conclusion, concentrations of acetic acid, at the levels normally measured in FLF, are not expected to affect markedly growth performance of piglets

Canibe, Nuria; Pedersen, Anni Øyan

2010-01-01

251

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

Directory of Open Access Journals (Sweden)

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,

A Alavi; Sh Moradi,; N Mirkheshti; A Ghadiri; F Hadizadeh

2007-01-01

252

Attenuation of acetic acid-induced gastric ulcer formation in rats by glucosylceramide synthase inhibitors.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Ceramide has been suggested to play a role in apoptosis during gastric ulcerogenesis. The present study is designed to investigate whether accumulated ceramide could serve as the effector molecules of ulcer formation in a rat model of acetic acid-induced gastric ulcer. METHODS: The effect of fumonisin B1, an inhibitor of ceramide synthase, and of d,l,-threo-1-phenyl-2-hexadecanoylamino-3-morpholino-1-propanol (PPMP) and N-butyldeoxynojirimycin (NB-DNJ), both inhibitors of glucosylceramide synthase, on the accumulation of ceramide and formation of gastric ulcer were examined in the rat model of acetic acid-induced gastric ulcer. RESULTS: Fumonisin B1 attenuated acetic acid-induced gastric ulcer formation, associated with a decrease in the number of apoptotic cells. Our results showed that it is neither the C18- nor the C24-ceramide itself, but the respective metabolites that were ulcerogenic, because PPMP and NB-DNJ attenuated gastric mucosal apoptosis and the consequent mucosal damage in spite of their reducing the degradation of ceramide. CONCLUSION: The ceramide pathway, in particular, the metabolites of ceramide, significantly contributes to acetic acid-induced gastric damage, possibly via enhancing apoptosis. On the other hand, PPMP and NB-DNJ treatment attenuated gastric mucosal apoptosis and ulcer formation despite increasing the ceramide accumulation, suggesting that it was not the ceramides themselves, but their metabolites that contributed to the ulcer formation in the acetic acid-induced gastric ulcer model.

Nakashita M; Suzuki H; Miura S; Taki T; Uehara K; Mizushima T; Nagata H; Hibi T

2013-02-01

253

Coproduction of acetic acid and electricity by application of microbial fuel cell technology to vinegar fermentation.  

UK PubMed Central (United Kingdom)

The coproduction of a useful material and electricity via a novel application of microbial fuel cell (MFC) technology to oxidative fermentation was investigated. We focused on vinegar production, i.e., acetic acid fermentation, as an initial and model useful material that can be produced by oxidative fermentation in combination with MFC technology. The coproduction of acetic acid and electricity by applying MFC technology was successfully demonstrated by the simultaneous progress of acetic acid fermentation and electricity generation through a series of repeated batch fermentations. Although the production rate of acetic acid was very small, it increased with the number of repeated batch fermentations that were conducted. We obtained nearly identical (73.1%) or larger (89.9%) acetic acid yields than that typically achieved by aerated fermentation (75.8%). The open-cycle voltages measured before and after fermentation increased with the total fermentation time and reached a maximum value of 0.521 V prior to the third batch fermentation. The maximum current and power densities measured in this study (19.1 ?A/cm² and 2.47 ?W/cm², respectively) were obtained after the second batch fermentation.

Tanino T; Nara Y; Tsujiguchi T; Ohshima T

2013-08-01

254

Acetic acid detection threshold in synthetic wine samples of a portable electronic nose.  

Science.gov (United States)

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. PMID:23262483

Macías, Miguel Macías; Manso, Antonio García; Orellana, Carlos Javier García; Velasco, Horacio Manuel González; Caballero, Ramón Gallardo; Chamizo, Juan Carlos Peguero

2012-12-24

255

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

256

Brettanomyces bruxellensis: effect of oxygen on growth and acetic acid production.  

UK PubMed Central (United Kingdom)

The influence of the oxygen supply on the growth, acetic acid and ethanol production by Brettanomyces bruxellensis in a glucose medium was investigated with different air flow rates in the range 0-300 l h(-1 ) x (0-0.5 vvm). This study shows that growth of this yeast is stimulated by moderate aeration. The optimal oxygen supply for cellular synthesis was an oxygen transfer rate (OTR) of 43 mg O(2) l(-1) x h(-1). In this case, there was an air flow rate of 60 l h(-1) (0.1 vvm). Above this value, the maximum biomass concentration decreased. Ethanol and acetic acid production was also dependent on the level of aeration: the higher the oxygen supply, the greater the acetic acid production and the lower the ethanol production. At the highest aeration rates, we observed a strong inhibition of the ethanol yield. Over 180 l h(-1) x (0.3 vvm, OTR =105 mg O(2) l(-1) x h(-1)), glucose consumption was inhibited and a high concentration of acetic acid (6.0 g x l(-1)) was produced. The ratio of "ethanol + acetic acid" produced per mole of consumed glucose using carbon balance calculations was analyzed. It was shown that this ratio remained constant in all cases. This makes it possible to establish a stoichiometric equation between oxygen supply and metabolite production.

Aguilar Uscanga MG; Délia ML; Strehaiano P

2003-04-01

257

Acetic acid detection threshold in synthetic wine samples of a portable electronic nose.  

UK PubMed Central (United Kingdom)

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.

Macías MM; Manso AG; Orellana CJ; Velasco HM; Caballero RG; Chamizo JC

2013-01-01

258

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

Directory of Open Access Journals (Sweden)

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; Antonio García Manso; Carlos Javier García Orellana; Horacio Manuel González Velasco; Ramón Gallardo Caballero; Juan Carlos Peguero Chamizo

2012-01-01

259

Pitting Corrosion of Tin by Acetate Anion in Acidic Media  

Directory of Open Access Journals (Sweden)

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

260

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

Directory of Open Access Journals (Sweden)

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

 
 
 
 
261

Xylitol dehydrogenase of acetic acid bacteria and gene thereof  

UK PubMed Central (United Kingdom)

Xylitol is produced by allowing xylitol dehydrogenase or cells instoduced with a DNA coding for xylitol dehydrogenase, which is a protein of the following (A) or (B) to act on D-xylulose, and collecting produced xylitol: (A) a protein which has the amino acid sequence of SEQ ID NO: 4; (B) a protein which has the amino acid sequence of SEQ ID NO: 4 including substitution, deletion, insertion, addition, or inversion of one or several amino acids, and has xylitol dehydrogenase activity.

Sugiyama Masakazu c/o Ajinomoto Co.Inc.; Tonouchi Naoto c/o Ajinomoto Co.Inc.; Suzuki Shunichi c/o Ajinomoto Co.Inc.; Yokozeki Kenzo c/o Ajinomoto Co.Inc.

262

Performance of Granular Activated Carbon to 2,4-Dichlorophenoxy Acetic Acid Aemoval from Aqueous Environments  

Directory of Open Access Journals (Sweden)

Full Text Available Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives: 2, 4-dichlorophenoxy acetic acid is a well-known herbicide which can be dangerous for  both human and animal health in different ways such as its presence in drinking water. This study aimed at Performance of granular activated carbon to 2-4-D removal from aqueous solution and assessing the relationship between COD and 2-4-D concentration Materials and Methods: This study is a lab-scale study. Firstly, different 2-4-D concentrations were prepared from Stock solution (1000 mg/L), and then their CODs were measured. Optimum pH for 2-4-D removal was determined and its absorption rate at different concentrations was measured. Results: Results showed a clear relationship between COD and 2-4-D concentration. On the other hand, COD removal increased as time elapsed, so that maximum removal 90% and 84% at initial 2-4-D concentrations of 50 and 100 mg/L were observed at contact time of 50 min respectively. Optimum pH for all concentrations was determined as 6. Conclusion: According to present study it can be concluded that activated carbon have be up to 90% of 2-4-D removal from water environment. In addition, a significant relationship was observed between COD and 2-4-D concentration, so that direct measurement of COD can be used instead of 2-4-D measurement. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;}

Meghdad Pirsaheb; Kiumars Sharafi; Abdollah Dargahi

2012-01-01

263

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

Energy Technology Data Exchange (ETDEWEB)

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

264

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

International Nuclear Information System (INIS)

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.

1998-01-01

265

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

Science.gov (United States)

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. PMID:23430312

Giannattasio, Sergio; Guaragnella, Nicoletta; Zdralevi?, Maša; Marra, Ersilia

2013-02-20

266

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

Directory of Open Access Journals (Sweden)

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.; Ra?enovi? A.; Malina J.

2010-01-01

267

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

Directory of Open Access Journals (Sweden)

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(acetate)4 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; BERNABÉ L RIVAS; CÉSAR PAREDES

2010-01-01

268

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

Scientific Electronic Library Online (English)

Full Text Available 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 at 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). (more) 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

2013-09-01

269

The lifespan-promoting effect of acetic acid and Reishi polysaccharide.  

UK PubMed Central (United Kingdom)

Using Caenorhabditis elegans as a model organism, various natural substances and commercial health-food supplements were screened to evaluate their effects on longevity. Among the substances tested, acetic acid and Reishi polysaccharide fraction 3 (RF3) were shown to increase the expression of the lifespan and longevity-related transcription factor DAF-16 in C. elegans. We have shown that RF3 activates DAF-16 expression via TIR-1 receptor and MAPK pathway whereas acetic acid inhibits the trans-membrane receptor DAF-2 of the insulin/IGF-1 pathway to indirectly activate DAF-16 expression. In addition, a mixture of acetic acid and RF3 possesses a combined effect 30-40% greater than either substance used alone. A proteomic analysis of C. elegans using 2-DE and LC-MS/MS was then carried out, and 15 differentially expressed proteins involved in the lifespan-promoting activity were identified.

Chuang MH; Chiou SH; Huang CH; Yang WB; Wong CH

2009-11-01

270

Acetic acid induces a programmed cell death process in the food spoilage yeast Zygosaccharomyces bailii.  

Science.gov (United States)

Here we show that 320-800 mM acetic acid induces in Zygosaccharomyces bailii a programmed cell death (PCD) process that is inhibited by cycloheximide, is accompanied by structural and biochemical alterations typical of apoptosis, and occurs in cells with preserved mitochondrial and plasma membrane integrity (as revealed by rhodamine 123 (Rh123) and propidium iodide (PI) staining, respectively). Mitochondrial ultrastructural changes, namely decrease of the cristae number, formation of myelinic bodies and swelling were also seen. Exposure to acetic acid above 800 mM resulted in killing by necrosis. The occurrence of an acetic acid-induced active cell death process in Z. bailii reinforces the concept of a physiological role of the PCD in the normal yeast life cycle. PMID:12702251

Ludovico, Paula; Sansonetty, Filipe; Silva, Manuel T; Côrte-Real, Manuela

2003-03-01

271

Acetic acid induces a programmed cell death process in the food spoilage yeast Zygosaccharomyces bailii.  

UK PubMed Central (United Kingdom)

Here we show that 320-800 mM acetic acid induces in Zygosaccharomyces bailii a programmed cell death (PCD) process that is inhibited by cycloheximide, is accompanied by structural and biochemical alterations typical of apoptosis, and occurs in cells with preserved mitochondrial and plasma membrane integrity (as revealed by rhodamine 123 (Rh123) and propidium iodide (PI) staining, respectively). Mitochondrial ultrastructural changes, namely decrease of the cristae number, formation of myelinic bodies and swelling were also seen. Exposure to acetic acid above 800 mM resulted in killing by necrosis. The occurrence of an acetic acid-induced active cell death process in Z. bailii reinforces the concept of a physiological role of the PCD in the normal yeast life cycle.

Ludovico P; Sansonetty F; Silva MT; Côrte-Real M

2003-03-01

272

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

UK PubMed Central (United Kingdom)

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.

Giannattasio S; Guaragnella N; Zdralevi? M; Marra E

2013-01-01

273

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

UK PubMed Central (United Kingdom)

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.

Thippeswamy BS; Mahendran S; Biradar MI; Raj P; Srivastava K; Badami S; Veerapur VP

2011-03-01

274

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

Science.gov (United States)

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

2010-12-24

275

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

Scientific Electronic Library Online (English)

Full Text Available 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 at 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). (more) 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

2013-01-01

276

A nitrilo-tri-acetic-acid/acetic acid route for the deposition of epitaxial cerium oxide films as high temperature superconductor buffer layers  

International Nuclear Information System (INIS)

A water based cerium oxide precursor solution using nitrilo-tri-acetic-acid (NTA) and acetic acid as complexing agents is described in detail. This precursor solution is used for the deposition of epitaxial CeO2 layers on Ni-5at%W substrates by dip-coating. The influence of the complexation behavior on the formation of transparent, homogeneous solutions and gels has been studied. It is found that ethylenediamine plays an important role in the gelification. The growth conditions for cerium oxide films were Ar-5% gas processing atmosphere, a solution concentration level of 0.25 M, a dwell time of 60 min at 900 oC and 5-30 min at 1050 oC. X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM), pole figures and spectroscopic ellipsometry were used to characterize the CeO2 films with different thicknesses. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) was used to determine the carbon residue level in the surface of the cerium oxide film, which was found to be lower than 0.01%. Textured films with a thickness of 50 nm were obtained. - Graphical abstract: Study of the complexation and hydrolysis behavior of Ce4+ ions in the presence of nitrilo-tri-acetic acid and the subsequent development of an aqueous chemical solution deposition route suited for the processing of textured CeO2 buffer layers on Ni-W tapes.

2010-01-01

277

EFFECT OF INDOLE ACETIC ACID (IAA) ON FRUIT DROP AND FRUIT QUALITY OF DATE PALM CULTIVARS  

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Full Text Available Effect of Indole-3-Acetic Acid (IAA) on fruit drop and fruit quality of date palm cultivars was assessed during 2011 at Agriculture Research Institute, Rata Kulachi D.I.Khan, Pakistan. The experiment was laid out in Randomized Complete Block (RCB) Design with two factors factorial arrangement and replicated three times. The concentrations of Indole Acetic Acid (IAA) were used as 50, 100, 150 and 200 ppm at Hababuke stage (immature green stage) and the cultivars used were Dhakki and Gulistan. The application of IAA significantly influenced the growth, yield components and reduced the fruit drop of date palm cultivars. Among cultivars, Dhakki cultivar showed more fruit length (4.97 cm), fruit diameter (3.03 cm), fruit weight (30.8 g) and pulp weight (29.16 g) when treated with 150 ppm Indole Acetic Acid, while the lower percent fruit drop (23.00%) and higher bunch weight (21.27 kg) was recorded in cultivar Gulistan with application of 150 ppm Indole Acetic Acid concentration. Cultivars effect was also significant for percent fruit drop, fruit length, fruit diameter, fruit weight, pulp weight and bunch weight. In case of interactions only length and pulp weight was found significant among all other parameter in both cultivars. Results revealed that application of Indole Acetic Acid as foliar spray @ 150 ppm showed good result to minimize the percent fruit drop of date palm cultivars and also affects other desirable parameters significantly. Therefore, the concentration of Indole Acetic Acid (IAA) @ 150 ppm should be applied as foliar spray at kimri stage (unripe stage) to minimize the fruit drop and to improve the fruit quality attributes of date palm cultivars.

Saeed Ahmed; Muhammad Sajid; Asif Latif; Nazeer Ahmed; Muhammad Junaid; Nasir Mahmood; Muhammad Umair

2013-01-01

278

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; Iliyasu Musa Omoniye; Wilson Oliver Hamman; Augustine Oseloka Ibegbu; Uduak Emmanuel Umana

2012-01-01

279

Synthesis and biological activity of thiazolyl-acetic acid derivatives as possible antimicrobial agents.  

Science.gov (United States)

5a-h, a series of (5-substituted-2-methyl-1,3-thiazole-4-yl) acetic acids as heterocyclic acetic acid derivatives, was designed and synthesized from ethyl acetoacetate. The synthesized compounds were screened for their antimicrobial activities against bacterial and fungal strains, and their characteristics were investigated by assays under various temperature and pH conditions. Cytotoxicity was evaluated with the use of sheep erythrocytes and human neonate dermal fibroblasts. Similarly, agents such as lauric acid 6 and parabens 7a-b, which are used as preservative agents for commercial cosmetics and detergents, were assayed for comparison. Although the structure of 5a is simple, comprising a thiazole attached with an octyl group and acetic acid moiety, the compound showed stronger and broader antibacterial and antifungal activities among the 5 series against the tested microbes other than gram-negative bacteria. Interestingly, 5a overcame the weak antifungal activity of parabens 7a-b. Also, the cytotoxicity of 5a was less than that of parabens 7a-b, especially to human dermal fibroblasts. These results suggest that thiazolyl-acetic acid 5a is a potentially effective biocide, and that it could be used as a preservative agent in commercially sold cosmetics and detergents, facilitated by the hydrophilic and charge properties of its carboxylic acid moiety. PMID:23796637

Shirai, Akihiro; Fumoto, Yasuko; Shouno, Tomoaki; Maseda, Hideaki; Omasa, Takeshi

2013-01-01

280

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

Directory of Open Access Journals (Sweden)

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

2011-01-01

 
 
 
 
281

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

Energy Technology Data Exchange (ETDEWEB)

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/m{sup 3} d) and high space time yield (30-35 kg COD/m{sup 3} 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 CO{sub 2} 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 CO{sub 2} content during biogas combustion is minimized and usage of other acidifying agents is omitted.

Vaiopoulou, E., E-mail: vaiop@env.duth.gr [Department of Environmental Engineering, Democritus University of Thrace, Vas. Sofias 12, 67 100 Xanthi (Greece); Melidis, P., E-mail: pmelidis@env.duth.gr [Department of Environmental Engineering, Democritus University of Thrace, Vas. Sofias 12, 67 100 Xanthi (Greece); Aivasidis, A., E-mail: aavazid@env.duth.gr [Department of Environmental Engineering, Democritus University of Thrace, Vas. Sofias 12, 67 100 Xanthi (Greece)

2011-02-28

282

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

283

Removal of cadmium from phosphoric acid-containing solutions  

UK PubMed Central (United Kingdom)

Process for the removal of cadmium from an aqueous, acidic, cadmium containing solution by electrodepositing the cadmium on conducting particulates present in a packed or fluidized bed cathode compartment of an electrolysis cell in which the aqueous; acidic, cadmium-containing solution contains phosphoric acid. The process is of particular interest for the removal of cadmium from phosphoric acid solutions which are obtained during the production of phosphorus-containing fertilizers from phosphorus rock.

Engels Karl Rainer; Nieuwhof Arjen; Spijkerman Johannes Bernardus Jozef

284

Enhancing the efficacy of photodynamic cancer therapy by radicals from plant auxin (indole-3-acetic acid).  

UK PubMed Central (United Kingdom)

Indole-3-acetic acid (plant auxin) has low toxicity but dramatically enhances the killing of mammalian cells on illuminating phenothiazinium dyes with red light. Suitable dyes include toluidine blue, used in cancer diagnosis because of localization in tumors, and methylene blue, used in experimental photodynamic therapy of cancer. The photosensitized oxidation of indole acetic acid forms a free radical that fragments in microseconds, forming reactive cytotoxins. Unlike conventional photodynamic therapy, requiring excitation of oxygen to the reactive singlet state, the treatment is effective even at the low oxygen levels common in tumors and with much lower light doses than normally used.

Folkes LK; Wardman P

2003-02-01

285

Design and synthesis of alkoxyindolyl-3-acetic acid analogs as peroxisome proliferator-activated receptor-?/? agonists.  

UK PubMed Central (United Kingdom)

A series of carbazole or phenoxazine containing alkoxyindole-3-acetic acid analogs were prepared as PPAR?/? agonists and their transactivation activities for PPAR receptor subtypes (?, ? and ?) were investigated. Structure-activity relationship studies disclosed the effect of the lipophilic tail, attaching position of the alkoxy group and N-benzyl substitution at indole. Compound 1b was the most potent for PPAR? and 3b for PPAR?. Molecular modeling suggested two different binding modes of our alkoxyindole-3-acetic acid analogs providing the insight into their PPAR activity.

Gim HJ; Li H; Lee E; Ryu JH; Jeon R

2013-01-01

286

Synthesis and Evaluation of Some New Pyrazolo Phenoxy Acetic Acid Derivatves for their Antitubercular Activity  

Directory of Open Access Journals (Sweden)

Full Text Available The present research work is aimed to synthesize some novel substituted pyrazolo phenoxy acetic acid. The ten new derivatives of phenoxy acetic acid (Scheme) were synthesized during the course of research work. The structures of compounds have been established by means of FT IR, 1H-NMR and elemental analysis. All the compounds were evaluated for anti-tubercular activity Middle brook 7H9 agar medium against H37Rv Strain.Out of ten compounds P1, P2,P6, P7, P8, P10 shown maximum anti-tubercular activity .

S.R.Pattan; R.L.Hullolikar; J. S.Pattan; B.P.Kapadnis; N.S. Dighe; S.S.Dengale; Ana Nikalje; S.A.Nirmal

2009-01-01

287

Excess molar volumes of binary and ternary mixtures of water, acetic acid and ethylene glycol  

Energy Technology Data Exchange (ETDEWEB)

The excess molar volumes of Water + Ethylene glycol binary mixture at 313.15 K, Acetic Acid + Ethylene Glycol binary mixture at 283.15 K, 293.15 K, 303.15 K, 313.15 K and Water + Acetic Acid + Ethylene Glycol ternary mixture at 283.15 K, 293.15 K were measured by using a vibration tube densimeter. The binary data were correlated to the Redlich-Kister polynomials and the excess volumes of ternary system were estimated by utilizing the parameters regressed from the experimental excess volumes of the binary and ternary mixtures.

Bae, H.K.; Song, H.C.; Lee, J.W. [Yeungnam University, Kyongsan (Korea, Republic of)

1998-02-01

288

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; S.B.Thakore

2012-01-01

289

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 (PAcetobacter aceti resulted in the production of acetic acid at a concentration of 61.4g/100g DM. The present study demonstrates an improved process of enzymatic hydrolysis of apple pomace to yield sugars and concomitant bioconversion to produce ethanol and acetic acid. PMID:23334018

Parmar, Indu; Rupasinghe, H P Vasantha

2012-12-20

290

The use of basic polymer sorbents for the recovery of acetic acid from dilute aqueous solution  

Energy Technology Data Exchange (ETDEWEB)

Measurements were made of uptakes of acetic acid and water from aqueous solution onto basic polymer sorbents. Sorption equilibria were interpreted through a chemical complexation model, yielding sorption affinities and saturation capacities for acetic acid. Basicity scales, such as pK/sub a/ and Gutmann donor number (DN), based upon the monomeric functional group chemistry were shown to explain the trends in sorption affinities. Solvent leaching was investigated as a means of regenerating the sorbents. It was found that regeneration can be improved by using solvents of high donicity. Aqueous ammonia proved to be effective for regenerating moderately strong base sorbents.

Garcia, A.A.; Kina, C.J.

1989-02-01

291

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 methof 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

292

PROCESS FOR PRODUCTION OF SUPPORTED CATALYST FOR ACETIC ACID PRODUCTION  

UK PubMed Central (United Kingdom)

A process for production of a supported catalyst that, when used for production of lower aliphatic carboxylic acids from oxygen and lower olefins, improves yields of the lower aliphatic carboxylic acids and minimizes production of carbon dioxide gas (CO2) by-product compared to the prior art. A compound comprising at least one element selected from elements of Groups 8, 9 and 10 of the Periodic Table, at least one chloride of an element selected from copper, silver and zinc, and a chloroauric acid salt, are loaded on a carrier, after which there are further loaded a compound comprising at least one element selected from gallium, indium, thallium, germanium, tin, lead, phosphorus, arsenic, antimony, bismuth, sulfur, selenium, tellurium and polonium, and a heteropoly acid.

MIYAJI ATSUYUKI

293

Survival of Listeria innocua in rainbow trout protein recovered by isoelectric solubilization and precipitation with acetic and citric acids.  

UK PubMed Central (United Kingdom)

During mechanical fish processing, a substantial amount of protein is discarded as by-products. Isoelectric solubilization and precipitation (ISP) is a process that uses extreme pH shifts to solubilize and precipitate protein from by-products to recover previously discarded protein. Typically, strong acids are used for pH reduction, but these acids do not have a pasteurization effect (6 log reduction) on bacterial load; therefore, organic acids were used during ISP processing to test the impact on Listeria innocua concentrations. Headed and gutted rainbow trout (Oncorhynchus mykiss) were inoculated with L. innocua, homogenized, and brought to the target pH with granular citric acid (pH 2.0 and 2.5) or glacial acetic acid (pH 3.0 and 3.5). Proteins were solubilized for 10 min at 4°C, and insoluble components (e.g., skin and insoluble protein) were removed by centrifugation. The remaining solution was pH shifted to the protein isoelectric point (pH 5.5) with sodium hydroxide, and precipitated protein was separated from the water. Microbial cells for each component (proteins, insolubles, and water) were enumerated on modified Oxford agar (MOX) and tryptic soy agar with 6% yeast extract (TSAYE). The sums of the surviving cells from each component were compared with the initial inoculum levels. No significant differences were observed between results obtained from TSAYE and from MOX (P > 0.05). Significant reductions in microbial populations were detected, regardless of pH or acid type (P < 0.05). The greatest reduction was at pH 3.0 with glacial acetic acid, resulting in a mean reduction of 6.41 log CFU/g in the recovered protein and 5.88 log CFU/g in the combined components. These results demonstrate the antimicrobial potential of organic acids in ISP processing.

Otto RA; Paker I; Bane L; Beamer S; Jaczynski J; Matak KE

2011-08-01

294

SYNTHESIS AND CHARACTERIZATION OF Zn(II) COMPLEX WITH THE ACETATE AND OROTIC ACID MK LIGANDS  

Directory of Open Access Journals (Sweden)

Full Text Available Semi-empirical calculations were used to characterize the orotic acid structure. The structures optimised using the PM3, AM1, and CNDO methods were compared with the crystallographic data. Orotic acid is a polydentate ligand due to the net charge on the atoms from the functional group. A compound was synthesized by reacting orotic acid with zinc acetate dihydrated in a neutral and non-aqueous media. This compound was characterized by elemental analysis, spectroscopy, and thermal analysis. The orotic acid replaces water molecules from zinc acetate dihydrate and coordinates through an exo-cyclic oxygen. Based on the probable structure, PM3 semi-empirical calculations of the complex of Zn(II) were performed. The semi-empirical calculations suggest that the orotic acid coordinated through C2=O group, where acetate groups maintained the bidentate coordination and the Zn- H3Or distance is greater than that the Zn- H2O distance for the Zn(II) acetate dihydrate.

GLORIA V SEGUEL; BERNABÉ L RIVAS; CÉSAR PAREDES

2010-01-01

295

SYNTHESIS AND CHARACTERIZATION OF Zn(II) COMPLEX WITH THE ACETATE AND OROTIC ACID MK LIGANDS  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Semi-empirical calculations were used to characterize the orotic acid structure. The structures optimised using the PM3, AM1, and CNDO methods were compared with the crystallographic data. Orotic acid is a polydentate ligand due to the net charge on the atoms from the functional group. A compound was synthesized by reacting orotic acid with zinc acetate dihydrated in a neutral and non-aqueous media. This compound was characterized by elemental analysis, spectroscopy, and (more) thermal analysis. The orotic acid replaces water molecules from zinc acetate dihydrate and coordinates through an exo-cyclic oxygen. Based on the probable structure, PM3 semi-empirical calculations of the complex of Zn(II) were performed. The semi-empirical calculations suggest that the orotic acid coordinated through C2=O group, where acetate groups maintained the bidentate coordination and the Zn- H3Or distance is greater than that the Zn- H2O distance for the Zn(II) acetate dihydrate.

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

2010-01-01

296

Removal of water from aqueous carboxylic acid streams.  

UK PubMed Central (United Kingdom)

Water is removed from an aqueous carboxylic acid stream containing stream by the use of a polyanhydride. The aqueous carboxylic acid contains 50% by weight, preferably 80% and in particular 95% by weight of carboxylic acid. The process is particular applicable to an acid stream containing acrylic acid to product acrylic acid of high purity. The polyanhydride can be a copolymer of maleic anhydride and diisobutylene cross-linked with divinylbenzene. The polyanhydride can be regenerated for use.

TENG HARRY HO I; BREMER NOEL JEROME; SHAW WILFRID GARSIDE

297

??????????????????? Synthesis of Acidic Ionic Liquids and Catalysts Application of Benzaldehyde Acetal  

Directory of Open Access Journals (Sweden)

Full Text Available   ??????N-???????????3?????????????????????????????????????????????????????????N-????-N(????)??-????????????????????????????????????????????????????????????????????????????2.8%?????2 h?????125???????????????88.59%?????????4?????????????  Three novel ionic liquids were synthesized using benzyl chloride, N-ethyl imidazole and pyridine as raw materials, the structure of these products were charactered, and these materials were applied to catalytic synthesis of benzaldehyde acetal. Compared with the traditional catalyst, the N-ethyl imidazole-N (p-sulfo) benzalhydantoin-chloride imidazole salt ionic liquids have good catalytic activity. The synthesis reaction of benzaldehyde acetal catalyzed by the acidic ionic liquid was studied. The result shows that the yield of benzaldehyde acetal was 88.59% under the following conditions: Molar percentage of catalyst relative to the reactants 2.8%, reaction temperature 125?C and reaction time 2 h. The catalytic activity maintains stable even the acidic ionic liquid was used 4 times.

???; ???

2012-01-01

298

Photoluminescence properties of poly(thiophene-3yl-acetic acid 8-quinolinyl ester) in solution and in acid medium  

International Nuclear Information System (INIS)

The photoluminescence characteristics and quantum yields of poly(thiophene-3-yl-acetic acid 8-quinolinyl ester) have been studied. Fluorescence measurements indicate that fluorescence quantum efficiency increases with decreasing the concentration of polymer solution. The quantum yield of the polymer in the solution is higher than that of the Rhodamine B dye at lower concentration. The behaviour of photoluminescence property is studied under different acidic conditions. The fluorescence quenching is observed in the acid medium without any shift in the wavelength.

2009-01-01

299

Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress.  

UK PubMed Central (United Kingdom)

When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile.

Lindberg L; Santos AX; Riezman H; Olsson L; Bettiga M

2013-01-01

300

Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress  

Science.gov (United States)

When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L?1, while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L?1 acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile.

Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

2013-01-01

 
 
 
 
301

Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress.  

Science.gov (United States)

When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile. PMID:24023914

Lindberg, Lina; Santos, Aline Xs; Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

2013-09-04

302

Role of the glyoxylate pathway in acetic acid production by Acetobacter aceti.  

UK PubMed Central (United Kingdom)

Wild-type Acetobacter aceti NBRC 14818 possesses genes encoding isocitrate lyase (aceA) and malate synthase (glcB), which constitute the glyoxylate pathway. In contrast, several acetic acid bacteria that are utilized for vinegar production lack these genes. Here, an aceA-glcB knockout mutant of NBRC 14818 was constructed and used for investigating the role of the glyoxylate pathway in acetate productivity. In medium containing ethanol as a carbon source, the mutant grew normally during ethanol oxidation to acetate, but exhibited slower growth than that of the wild-type strain as the accumulated acetate was oxidized. The mutant grew similarly to that of the wild-type strain in medium containing glucose as a carbon source, indicating that the glyoxylate pathway was not necessary for glucose utilization. However, in medium containing both ethanol and glucose, the mutant exhibited significantly poorer growth and lower glucose consumption compared to the wild-type strain. Notably, the mutant oxidized ethanol nearly stoichiometrically to acetate, which was retained in the medium for a longer period of time than the acetate produced by wild-type strain. The features of the aceA-glcB knockout mutant revealed here indicate that the lack of the glyoxylate pathway is advantageous for industrial vinegar production by A. aceti.

Sakurai K; Yamazaki S; Ishii M; Igarashi Y; Arai H

2013-01-01

303

Role of the glyoxylate pathway in acetic acid production by Acetobacter aceti.  

Science.gov (United States)

Wild-type Acetobacter aceti NBRC 14818 possesses genes encoding isocitrate lyase (aceA) and malate synthase (glcB), which constitute the glyoxylate pathway. In contrast, several acetic acid bacteria that are utilized for vinegar production lack these genes. Here, an aceA-glcB knockout mutant of NBRC 14818 was constructed and used for investigating the role of the glyoxylate pathway in acetate productivity. In medium containing ethanol as a carbon source, the mutant grew normally during ethanol oxidation to acetate, but exhibited slower growth than that of the wild-type strain as the accumulated acetate was oxidized. The mutant grew similarly to that of the wild-type strain in medium containing glucose as a carbon source, indicating that the glyoxylate pathway was not necessary for glucose utilization. However, in medium containing both ethanol and glucose, the mutant exhibited significantly poorer growth and lower glucose consumption compared to the wild-type strain. Notably, the mutant oxidized ethanol nearly stoichiometrically to acetate, which was retained in the medium for a longer period of time than the acetate produced by wild-type strain. The features of the aceA-glcB knockout mutant revealed here indicate that the lack of the glyoxylate pathway is advantageous for industrial vinegar production by A. aceti. PMID:22902276

Sakurai, Kenta; Yamazaki, Shoko; Ishii, Masaharu; Igarashi, Yasuo; Arai, Hiroyuki

2012-08-16

304

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

305

[Concentrations and acidity contributions of acetate and formate in precipitation at 14 stations of China].  

UK PubMed Central (United Kingdom)

To investigate the concentrations of organic acids in precipitation in China and their contributions to the total acidity of precipitation, samples were taken at 14 stations of regional representativeness in 2007 and analyzed for acetate and formate using ion chromatography. In this paper, data of acetate and formate in precipitation at 14 stations are presented, wet depositions of these organic acids are calculated, and contributions of them to the total free acidity (TFA) of precipitation are estimated. Based on the measurements, the mean concentrations of formate at different stations were in the range of 0.96-3.43 micromol/L, and those of acetate in the range of 0-5.13 micromol/L, close to the levels at remote sites in other countries and at the lower ends of concentration ranges from previous measurements in China. Comparisons indicate that the concentrations of the organic acids at remote sites are lower than those at sites in the vicinity of urban areas. The annual wet depositions of formate and acetate were estimated to be in the ranges of 0.38-4.18 mmol/(m2 x a) and 0.06-5.87 mmol/(m2 x a), respectively, with larger depositions in southern China and smaller depositions in northern China. The relative contributions of the two organic acids to the TFA of precipitation were estimated to be in the range of 0.02%-51.6%, with an overall average of 2.95%. This suggests that although acid rain in China is mainly caused by emissions of sulfur and nitrogen oxides, organic acids can significantly contribute to the acidification of precipitation in some regions and during some periods, hence need to be included in observational studies of acid rain.

He XH; Xu XB; Yu XL; Tang J

2010-04-01

306

Kinetics of reaction between Pu(IV) and (hydroxyamino) acetic acid in nitric acid solution  

International Nuclear Information System (INIS)

In order to understand the (hydroxyamino) acetic acid (HAAA) of reduction performance to Pu(IV), the kinetics of reaction between Pu(IV) and HAAA in nitrous acid solution was determined by spectrophotometrically method. The rate equation is -dc(Pu(IV))/dt=kc(Pu(IV))c1.50 (HAAA)c-1.00(H+) c-0.63(NO3-), where reaction rate constant k=(42.1±4.2)(mol/L)-0.13·s-1 at 15.8 degree C. The activation energy Ea is (78.0±1.6) kJ/mol. Effects of c(HAAA), c(H+), c(Fe3+), c(UO22+), ionic strength and temperature on reduction rate of Pu(IV) were investigated. Pu(IV) can be reduced to Pu(III) rapidly by HAAA under usual conditions. The reaction rate can be accelerated by increasing concentration of HAAA, decreasing HNO3 concentration and ionic strength as well as rising temperature. The influence of UO22+ on reaction rate is negligible. The application of HAAA in the separation between Pu and U is promising. (authors)

2009-01-01

307

Relationship between changes in the total concentration of acetic acid bacteria and major volatile compounds during the acetic acid fermentation of white wine  

UK PubMed Central (United Kingdom)

BACKGROUND: In the scope of the wine vinegar production, this paper provides comprehensive information about the evolution of some volatile compounds during the biological acetification cycle. These data were compared with the acidity, cell concentration and ethanol concentration. Such information may allow a better understanding of the complex biological processes involved. RESULTS: The volatile compounds 2?phenylethanol, diethyl succinate (diethyl butanedioate), meso?2,3?butanediol (meso?butane?2,3?diol), levo?2,3?butanediol (levo?butane?2,3?diol), methanol and ethyl acetate exhibited no significant changes between the starting wine and produced vinegar, whereas the rest [acetoin (3?hydroxybutan?2?one) excepted] ethyl lactate (ethyl 2?hydroxypropanoate), isoamyl alcohols (3?methylbutan?1?ol and 2?methylbutan?1?ol), isobutanol (2?methylpropan?1?ol), 1?propanol (propan?1?ol), and acetaldehyde were consumed in substantial amounts during the process. Additionally, their specific evolution patterns alongside bacterial cell concentrations, acidity and ethanol concentration are shown. CONCLUSION: Concentrations of acetic acid bacteria at the end of the acetification cycle were found to vary because of cell lysis, a result of the high acidity and low ethanol concentration of the medium. Variations were similar to those in some volatile compounds, which suggests their involvement in the metabolism of acetic bacteria. The results testify to the usefulness of this pioneering study and suggest that there should be interest in similar, more detailed studies for a better knowledge of the presence of certain volatile compounds and metabolic activity in cells effecting the acetification of wine. Copyright

Baena?Ruano Silvia; Santos?Dueñas InésM; Mauricio JuanC; García?García Isidoro

2010-12-01

308

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

Directory of Open Access Journals (Sweden)

Full Text Available We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ~1200 and ~1400 Gmol/yr, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

F. Paulot; D. Wunch; J. D. Crounse; G. C. Toon; D. B. Millet; P. F. DeCarlo; C. Vigouroux; N. M. Deutscher; G. González Abad; J. Notholt; T. Warneke; J. W. Hannigan; C. Warneke; J. A. de Gouw; E. J. Dunlea; M. De Mazière; D. W. T. Griffith; P. Bernath; J. L. Jimenez; P. O. Wennberg

2010-01-01

309

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

Directory of Open Access Journals (Sweden)

Full Text Available We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ~1200 and ~1400 Gmol yr?1, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

F. Paulot; D. Wunch; J. D. Crounse; G. C. Toon; D. B. Millet; P. F. DeCarlo; C. Vigouroux; N. M. Deutscher; G. González Abad; J. Notholt; T. Warneke; J. W. Hannigan; C. Warneke; J. A. de Gouw; E. J. Dunlea; M. De Mazière; D. W. T. Griffith; P. Bernath; J. L. Jimenez; P. O. Wennberg

2011-01-01

310

The effect of volatile fatty acids (VFAs) on nutrient removal in SBR with biomass adapted to dairy wastewater.  

UK PubMed Central (United Kingdom)

This study aims to determine the effect of volatile fatty acids on nitrates and orthophosphate removal in a sequencing batch reactor (SBR) with activated sludge biomass adapted to process dairy wastewater. The research also determine whether it is the type of fatty acid applied that is responsible for the effectiveness of denitrification and dephosphatation at varying nitrate:orthophosphate ratios, or whether these processes are additionally affected by the presence of microorganisms that have adapted to the specific carbon composition of the wastewater being treated. At the beginning of an operating cycle SBRs were dosed with VFAs to provide a source of carbon. A comparative analysis was performed of nitrate and orthophosphate removal at initial nitrate concentrations of 1.22, 7.3 and 15.2 mgN(NO3)L?¹. Doses of fatty acids were approximately 10.5 mg?¹COD·mgP(PO4). They consisted of acetic, propionic, butyric, isobutyric, valeric, isovaleric and caproic acids. Increases of nitrate concentration from 1.22 to 15.2 mg N(NO3)L?¹ were observed to reduce the quantity of removed orthophosphate depending on the fatty acid applied, from 7.2-9.2 mgP(PO4)L to 4.5 - 6.7 mgP(PO4)L. Every increase in the removed nitrates by 5.0 mgN(NO3)L?¹ was accompanied by a decrease in the removed orthophosphate of around 1 mgP(PO4)L?¹. The reactor containing acetic acid was found to remove the highest amount of orthophosphate irrespective of the nitrates concentration. Acids present in significant amount in dairy wastewaters (i.e. acetic, propionic and butyric) were more effective source of carbon in the denitrification process compared to low concentration acids.

Janczukowicz W; Rodziewicz J; Czaplicka K; K?odowska I; Mielcarek A

2013-01-01

311

Indole-3-acetic acid and fusicoccin cause cytosolic acidification of corn coleoptile cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Microelectrodes were used to measure simultaneously the effects of indole-3-acetic acid (IAA) on membrane potential and cytosolic pH of corn coleoptile cells. IAA caused an initial depolarization followed by hyperpolarization, the latter displaying rhythmic oscillations. The extent of the changes in...

Felle, Hubert; Brummer, Benno; Bertl, Adam; Parish, Roger W.

312

Hydrolysis of rice straw and rice husk to pentoses and the production of acetic acid  

Energy Technology Data Exchange (ETDEWEB)

The hemicellulose component of rice straw and rice hulls was quantatively hydrolyzed to pentoses with 1-2% H2SO4 at high temperature. This pentose solution consisted mainly of xylose, arabinose, and glucose. It was then fermented to produce acetic acid by an anaerobic, thermophilic strain of Clostridium thermoaceticum.

Yu, N.; Yin, F.S.; Hwang, A.L.; Hao, P.L.C.; Wang, S.D.; Yeh, Y.L.

1981-01-01

313

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Štrkalj A.; Ra?enovi? A.; Malina J.

314

Vinegar (20% acetic acid) broadcast application for broadleaf weed control in spring-transplanted onions  

Science.gov (United States)

Organic weed control research was conducted in southeast Oklahoma to determine the effect of broadcast over-the-top applications of acetic acid (vinegar) on weed control efficacy, crop injury and onion yields. The experiment included 6 weed control treatments (2 application volumes, 2 hand-weeding ...

315

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...

316

Vibrational spectral studies of solutions at elevated temperatures and pressures. IX. Acetic acid  

Energy Technology Data Exchange (ETDEWEB)

Raman spectra of glacial acetic acid from 350 to 3700 cm/sup -1/ have been measured at temperatures up to 275/sup 0/C and at a pressure of 9 MPa. Raman spectra of aqueous solutions of acetic acid from 3.9 to 16 molar have been measured up to 200/sup 0/C at a pressure of 7 MPa. The spectral region 800 to 1850 cm/sup -1/ for both glacial acetic acid and its aqueous solutions have been studied in detail since this region is significantly affected by variations in temperature and concentration. An interpretation of the bands in this spectral region was made with the aid of factor analysis, difference spectroscopy, band resolution techniques and the existing extensive literature. The results suggest that the major equilibrium in glacial acetic acid is between cyclic and linear dimers; however, in aqueous solutions in the concentration range studied, mono- and di-hydrated dimers and cyclic dimers are the predominant species.

Semmler, J.; Irish, D.E.

1988-09-01

317

EXTRACTION AND ELECTROSPINNING OF ZEIN EXTRACTED FROM CORN GLUTEN MEAL USING ACETIC ACID  

Science.gov (United States)

It has been demonstrated that zein fibers can be produced using the electrospinning technique. Fibers electrospun from acetic acid solution under suitable conditions provide fibers with a more consistent morphology (round 0.5-2.0 micro fibers) compared to fibers produced from aqueous ethanol soluti...

318

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; Mohammad Ali Asadi; Rohullah Dehghani; Ali Zarei Mahmoudabadi; Fariba Rayegan; Hossein Hooshyar; Ahmad Khorshidi

2010-01-01

319

Trifluoroacetic anhydride promoted tandem conjugate addition of boronic acids/acetal ring opening.  

UK PubMed Central (United Kingdom)

A new stereoselective tandem reaction consisting of the metal-free conjugate addition of boronic acids followed by an intramolecular ring opening of a cyclic acetal has been disclosed. Optically pure polysubstituted tetrahydropyrans have been synthesized diastereoselectively by this new reaction. Two new C-C bonds and up to three stereocenters are formed in a single step, allowing the generation of quaternary stereocenters.

Roscales S; Csáky AG

2012-03-01

320

1-[3-(4-Nitrophenyl)propanoyl]urea acetic acid monosolvate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The title compound, C10H11N3O4·C2H4O2, was prepared by an electrochemical technique. In the crystal, acetic acid molecules are involved in hydrogen bonding to two separate propanoylurea molecules, acting as a donor in an O—H...O interaction and as an acceptor in two N—H...O interact...

Soraya Merzouki; Chabane Mouats; El-Eulmi Bendeif; Sebastien Pillet; Karim Bouchouit

 
 
 
 
321

Racimisation of (R) –Alpha – Ethyl -2-Oxo-1-Pyrrolidine Acetic acid with Thionyl Chloride  

Directory of Open Access Journals (Sweden)

Full Text Available We report the new synthetic methodology and Racimisation of (R)-Alpha-ethyl-2-oxo-1-pyrrolidine acetic acid with thionyl chloride resulting compound is charactarised and confirmed by SOR, racimisation is occurs by using thionyl chloride, the resulting of the yield is 83%.

K.Chandra sekhara reddy; I.V.Kasi viswanath

2013-01-01

322

Effect of Indole Acetic Acid on in vitro Growth and Biomass Production of Some Soil Fungi  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Effect of different concentrations of Indole Acetic Acid (IAA) was studied on growth of four species of soil fungi namely; Aspergillus oryzae, A. terreus, A. niger and Alternaria alternata. The hormone was applied in various concentrations. Increased growth rate and bioma...

Ghazala Nasim; Memoona Rahman; Asad Shabbir

323

Antinociceptive activity of lectins from Diocleinae seeds on acetic acid-induced writhing test in mice.  

UK PubMed Central (United Kingdom)

Diocleinae lectins administered per oral route in mice inhibited the abdominal constrictions induced by acetic acid. The percentage of the lectins antinociception varied from 61% for Canavalia grandiflora (ConGf) to 20% for Dioclea violacea. ConGf inhibited contortions at all doses tested but not in a dose-dependent manner, involving carbohydrate recognition.

Holanda FR; Coelho-de-Sousa AN; Assreuy AM; Leal-Cardoso JH; Pires AF; do Nascimento KS; Teixeira CS; Cavada BS; Santos CF

2009-01-01

324

Production of the Phytohormone Indole-3-Acetic Acid by Estuarine Species of the Genus Vibrio?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Strains of Vibrio spp. isolated from roots of the estuarine grasses Spartina alterniflora and Juncus roemerianus produce the phytohormone indole-3-acetic acid (IAA). The colorimetric Salkowski assay was used for initial screening of IAA production. Gas chromatography-mass spectroscopy (GC-MS) was th...

Gutierrez, Casandra K.; Matsui, George Y.; Lincoln, David E.; Lovell, Charles R.

325

Synthesis of (2-methyl-4-nitro-1-[15N1]imidazolyl)acetic acid  

International Nuclear Information System (INIS)

[en] 1,4-Dinitro-2-methylimidazole reacts under mild conditions with glycine to yield (2-methyl-4-nitro-1-imidazolyl)acetic acid. The use of [15N]glycine gives a product having a labelled nitrogen in 1 position of 4-nitroimidazole. (Author)

1992-01-01

326

Gluconobacter as Well as Asaia Species, Newly Emerging Opportunistic Human Pathogens among Acetic Acid Bacteria ? †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Acetic acid bacteria (AAB) are broadly used in industrial food processing. Among them, members of the genera Asaia, Acetobacter, and Granulibacter were recently reported to be human opportunistic pathogens. We isolated AAB from clinical samples from three patients and describe here the clinical and ...

Alauzet, Corentine; Teyssier, Corinne; Jumas-Bilak, Estelle; Gouby, Anne; Chiron, Raphael; Rabaud, Christian; Counil, François

327

Improved synthesis of 3-(dialkylaminomethyl)-indole in acetic acid aqueous solution under ultrasound irradiation.  

UK PubMed Central (United Kingdom)

Synthesis of Mannich bases related to gramine via Mannich reaction of secondary amine, formaldehyde and indole or N-methylindole can be carried out in 69-98% yields in acetic acid aqueous solution at 35°C under ultrasound irradiation. Compared with the method using stirring, the present procedure provided several advantages such as milder conditions, shorter reaction time and higher yield.

Li JT; Sun SF; Sun MX

2011-01-01

328

Improved synthesis of 3-(dialkylaminomethyl)-indole in acetic acid aqueous solution under ultrasound irradiation.  

Science.gov (United States)

Synthesis of Mannich bases related to gramine via Mannich reaction of secondary amine, formaldehyde and indole or N-methylindole can be carried out in 69-98% yields in acetic acid aqueous solution at 35°C under ultrasound irradiation. Compared with the method using stirring, the present procedure provided several advantages such as milder conditions, shorter reaction time and higher yield. PMID:20646952

Li, Ji-Tai; Sun, Shao-Feng; Sun, Ming-Xuan

2010-06-02

329

Removal of benzylidene acetal and benzyl ether in carbohydrate derivatives using triethylsilane and Pd/C.  

UK PubMed Central (United Kingdom)

Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzyl ethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH(3)OH at room temperature. A variety of carbohydrate diol derivatives were prepared from their benzylidene derivatives in excellent yield.

Santra A; Ghosh T; Misra AK

2013-01-01

330

Removal of benzylidene acetal and benzyl ether in carbohydrate derivatives using triethylsilane and Pd/C.  

Science.gov (United States)

Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzyl ethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH(3)OH at room temperature. A variety of carbohydrate diol derivatives were prepared from their benzylidene derivatives in excellent yield. PMID:23400301

Santra, Abhishek; Ghosh, Tamashree; Misra, Anup Kumar

2013-01-14

331

Removal of benzylidene acetal and benzyl ether in carbohydrate derivatives using triethylsilane and Pd/C  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzyl ethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH3OH at room temperature. A variety of carbohydrate diol derivatives were prepared ...

Santra, Abhishek; Ghosh, Tamashree; Misra, Anup Kumar

332

Removal of benzylidene acetal and benzyl ether in carbohydrate derivatives using triethylsilane and Pd/C  

Directory of Open Access Journals (Sweden)

Full Text Available Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzyl ethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH3OH at room temperature. A variety of carbohydrate diol derivatives were prepared from their benzylidene derivatives in excellent yield.

Abhishek Santra; Tamashree Ghosh; Anup Kumar Misra

2013-01-01

333

Pentose oxidation by acetic Acid bacteria led to a finding of membrane-bound purine nucleosidase.  

UK PubMed Central (United Kingdom)

D-Ribose and 2-deoxy-D-ribose were oxidized to 4-keto-D-ribonate and 2-deoxy-4-keto-D-ribonate respectively by oxidative fermentation, and the chemical structures of the oxidation products were confirmed to be as expected. Both pentoses are important sugar components of nucleic acids. When examined, purine nucleosidase activity predominated in the membrane fraction of acetic acid bacteria. This is perhaps the first finding of membrane-bound purine nucleosidase.

Adachi O; Hours RA; Akakabe Y; Shinagawa E; Ano Y; Yakushi T; Matsushita K

2013-05-01

334

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 m...

Hossein Tajik; Esmaeal Tamaddonfard; Nasrin Hamzeh-Gooshchi

335

Microbial process for the preparation of acetic acid as well as solvent for its extraction from the fermentation broth  

Energy Technology Data Exchange (ETDEWEB)

A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched di-alkyl amines. This solvent is substantially devoid of mono-alkyl amines and alcohols. Solvent mixtures formed of such a modified solvent with a desired cosolvent, preferably a low boiling hydrocarbon which forms an azeotrope with water are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.

Gaddy, James L. (Fayetteville, AR); Clausen, Edgar C. (Fayetteville, AR); Ko, Ching-Whan (Fayetteville, AR); Wade, Leslie E. (Corpus Christi, TX); Wikstrom, Carl V. (Fayetteville, AR)

2002-01-01

336

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

UK PubMed Central (United Kingdom)

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.

Harner NK; Bajwa PK; Habash MB; Trevors JT; Austin GD; Lee H

2013-10-01

337

Dichromate dosimetry. The effect of acetic acid on the radiolytic reduction yield  

International Nuclear Information System (INIS)

The radiation chemical yield for the reduction of dichromate, Cr(VI)?Cr3+, in an acidic aqueous perchloric acid solution of potassium dichromate, may be increased from 0.04 to > 0.2 ?mol J-1 by adding acetic acid. The increased yield, G[-(Cr2O7)2-] is about the same in N2- and O2-saturated solutions. The molar linear absorption coefficient at 350 nm also is the same in both solutions (?sub(m) = 2800 M-1 cm-1) at pH 0.4. The proposed mechanism to explain the enhanced response in N2-saturated solutions involves the efficient reaction of acetic acid with hydroxyl radicals by the abstraction of H from the methyl group; the resulting acid radicals react with relatively high yield to reduce Cr(VI). In O2-saturated solution, the acetic acid radical apparently goes through an acetic acid peroxyl radical by a bimolecular reaction to the tetroxide intermediate of acetic acid, which releases H2O2 with relatively high yield by a Bennett-type reaction. This additional H2O2, as a reducing agent, reacts slowly with dichromate and boosts the value of G[-(Cr2O7)2-]. The negative slope of the response (?? vs dose) continues to increase during the period immediately after irradiation of oxygenated solution, due to slow reaction of radiolytically-produced H2O2 with dichromate. There is also in both O2- and N2-saturated solution a long-term slow reaction involving oxidation of the organic substrate (in this case, acetic acid). Because of these instabilities, the solutions cannot readily be used for dosimetry without the presence of silver ions, which in the oxidized state, Ag2+, act to stabilize the solution after irradiation. The addition of silver dichromate at a concentration of 0.1 mM decreases the yield to G:-(Cr2O7) 2-] = 0.17 ?mol J-1, but greatly improves the stability of the solution after irradiation. The absorbed dose range for the modified dichromate dosimeter when analyzed spectrophotometrically at 350 nm wavelength is approx. 2 x 102-2 x 103Gy. (author)

1988-01-01

338

Dichromate dosimetry. The effect of acetic acid on the radiolytic reduction yield  

Energy Technology Data Exchange (ETDEWEB)

The radiation chemical yield for the reduction of dichromate, Cr(VI)->Cr/sup 3+/, in an acidic aqueous perchloric acid solution of potassium dichromate, may be increased from 0.04 to > 0.2 ..mu..mol J/sup -1/ by adding acetic acid. The increased yield, G(-(Cr/sub 2/O/sub 7/)/sup 2-/) is about the same in N/sub 2/- and O/sub 2/-saturated solutions. The molar linear absorption coefficient at 350 nm also is the same in both solutions (epsilonsub(m) = 2800 M/sup -1/ cm/sup -1/) at pH 0.4. The proposed mechanism to explain the enhanced response in N/sub 2/-saturated solutions involves the efficient reaction of acetic acid with hydroxyl radicals by the abstraction of H from the methyl group; the resulting acid radicals react with relatively high yield to reduce Cr(VI). In O/sub 2/-saturated solution, the acetic acid radical apparently goes through an acetic acid peroxyl radical by a bimolecular reaction to the tetroxide intermediate of acetic acid, which releases H/sub 2/O/sub 2/ with relatively high yield by a Bennett-type reaction. This additional H/sub 2/O/sub 2/, as a reducing agent, reacts slowly with dichromate and boosts the value of G(-(Cr/sub 2/O/sub 7/)/sup 2-/). The negative slope of the response (..delta..ALPHA vs dose) continues to increase during the period immediately after irradiation of oxygenated solution, due to slow reaction of radiolytically-produced H/sub 2/O/sub 2/ with dichromate. There is also in both O/sub 2/- and N/sub 2/-saturated solution a long-term slow reaction involving oxidation of the organic substrate (in this case, acetic acid). Because of these instabilities, the solutions cannot readily be used for dosimetry without the presence of silver ions, which in the oxidized state, Ag/sup 2+/, act to stabilize the solution after irradiation. (Abstract Truncated)

Al-Sheikhly, M.; Hussmann, M.H.; McLaughlin, W.L.

1988-01-01

339

Studies on manganese nodule leached residue 4. Physicochemical characterization and catalytic activity of acetic acid treated manganese nodule leached residue.  

Science.gov (United States)

The catalytic activity of water-washed manganese nodule leached residue (WMNLR) samples improved by treating with acetic acid. The effects of acetic acid treatment on the physicochemical properties and catalytic activity of manganese nodule leached residue have been studied. The surface area, surface oxygen, surface hydroxyl groups, surface acidity, electron donating properties, etc., increase gradually with acid treatment up to 0.5 M and thereafter show a decreasing trend. The rate constant of H2O2 decomposition, catalytic activity of CO oxidation, and esterification of acetic acid also show a similar trend to that of surface properties. PMID:16084522

Dash, S S; Mallik, S; Parida, K M; Mohapatra, B K

2005-08-09

340

Studies on manganese nodule leached residue 4. Physicochemical characterization and catalytic activity of acetic acid treated manganese nodule leached residue.  

UK PubMed Central (United Kingdom)

The catalytic activity of water-washed manganese nodule leached residue (WMNLR) samples improved by treating with acetic acid. The effects of acetic acid treatment on the physicochemical properties and catalytic activity of manganese nodule leached residue have been studied. The surface area, surface oxygen, surface hydroxyl groups, surface acidity, electron donating properties, etc., increase gradually with acid treatment up to 0.5 M and thereafter show a decreasing trend. The rate constant of H2O2 decomposition, catalytic activity of CO oxidation, and esterification of acetic acid also show a similar trend to that of surface properties.

Dash SS; Mallik S; Parida KM; Mohapatra BK

2006-02-01

 
 
 
 
341

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 100?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

342

The Formation of Acetic Acid (CH3COOH) in Interstellar Ice Analogs  

Science.gov (United States)

Binary ice mixtures of methane (CH4) and carbon dioxide (CO 2) ices were irradiated at 12 K with energetic electrons to mimic the energy transfer processes that occur in the track of the trajectories of MeV cosmic-ray particles. The formation of trans-acetic acid (CH3COOH) was established through the appearance of new bands in the infrared spectrum at 1780, 1195, 1160, 1051, and 957 cm-1 two dimeric forms of acetic acid were assigned via absorptions at 1757 and 1723 cm-1 . During warm-up of the ice sample, the mass spectrometer recorded peaks of m/z values of 60 and 45 associated with the C2H 4O2+ and COOH+ molecular ion and fragment, respectively. The kinetic fits of the column densities of the acetic acid molecule suggest that the initial step of the formation process appears to be the cleavage of a carbon-hydrogen bond from methane to generate the methyl radical plus atomic hydrogen. The hydrogen atom holds excess kinetic energy allowing it to overcome entrance barriers required to add to a carbon dioxide molecule, generating the carboxyl radical (HOCO). This radical can recombine with the methyl radical to form acetic acid molecule. Similar processes are expected to form acetic acid in the interstellar medium, thus providing alternatives to gas-phase processes for the generation of complex chemical species whose fractional abundances compared to molecular hydrogen of typically a few×10-9 cannot be accounted for by solely gas-phase chemistry.

Bennett, Chris J.; Kaiser, Ralf I.

2007-05-01

343

Antiseptic therapy with a polylacticacid-acetic acid matrix in burns.  

UK PubMed Central (United Kingdom)

Bacterial colonization and infection are still the major causes of delayed healing and graft rejection following burns and they are furthermore the basis for second and third hit sepsis. Topical treatment is necessary to reduce the incidence of burn wound infection. Silver sulphadiazine (SD-Ag) is a frequently used microbicidal agent. However, this treatment causes adverse reactions and side-effects. Additionally, in recent years multiresistant bacteria, which have not been treated sufficiently, are on the rise. On the basis of experimental data and clinical application of a polylacticacid-acetic acid matrix, we performed this study to establish the effectiveness of the antiseptic therapy with the topical application of a polylacticacid-acetic acid matrix to provide an alternative method for burn treatment, using SD-Ag as a reference. Twenty patients with IIb° or III° burns from the Plastic Surgery and Burns Unit were treated within a matched pair comparative setting. One burned area was treated with SD-Ag, the other corresponding area with the polylacticacid-acetic acid matrix. All patients underwent a necrectomy 4-5 days after the trauma. The excised burned skin was sent to our microbiological laboratory to determine the different bacteria per gram in this tissue. Despite the number of 20 patients, statistical significance was not achieved, there were tendencies to a better antiseptic effectiveness of the polylacticacid-acetic acid matrix. These results suggest that the polylacticacid-acetic acid matrix should be studied in greater depth and could be used as a valid alternative for the topical treatment of burns, as it is equivalent or even more effective than SD-Ag.

Ryssel H; Gazyakan E; Germann G; Hellmich S; Riedel K; Reichenberger MA; Radu CA

2010-09-01

344

Antiseptic therapy with a polylacticacid-acetic acid matrix in burns.  

Science.gov (United States)

Bacterial colonization and infection are still the major causes of delayed healing and graft rejection following burns and they are furthermore the basis for second and third hit sepsis. Topical treatment is necessary to reduce the incidence of burn wound infection. Silver sulphadiazine (SD-Ag) is a frequently used microbicidal agent. However, this treatment causes adverse reactions and side-effects. Additionally, in recent years multiresistant bacteria, which have not been treated sufficiently, are on the rise. On the basis of experimental data and clinical application of a polylacticacid-acetic acid matrix, we performed this study to establish the effectiveness of the antiseptic therapy with the topical application of a polylacticacid-acetic acid matrix to provide an alternative method for burn treatment, using SD-Ag as a reference. Twenty patients with IIb° or III° burns from the Plastic Surgery and Burns Unit were treated within a matched pair comparative setting. One burned area was treated with SD-Ag, the other corresponding area with the polylacticacid-acetic acid matrix. All patients underwent a necrectomy 4-5 days after the trauma. The excised burned skin was sent to our microbiological laboratory to determine the different bacteria per gram in this tissue. Despite the number of 20 patients, statistical significance was not achieved, there were tendencies to a better antiseptic effectiveness of the polylacticacid-acetic acid matrix. These results suggest that the polylacticacid-acetic acid matrix should be studied in greater depth and could be used as a valid alternative for the topical treatment of burns, as it is equivalent or even more effective than SD-Ag. PMID:20731796

Ryssel, Henning; Gazyakan, Emre; Germann, Günter; Hellmich, Susanne; Riedel, Katrin; Reichenberger, Matthias A; Radu, Christian A

2010-08-19

345

2,4-dicholorophenoxy acetic acid reduced odor herbicidal mixture  

UK PubMed Central (United Kingdom)

A nonionic surfactant blend is described for use with odoriferous compatible herbicides. The nonionic surfactant blend includes an effective amount of an acidulated soybean soapstock. The acidulated soybean soapstock includes a range of total fatty acids of about 94%-to-96% by volume and a moisture content of not more than about 5% by volume. The present invention also includes a method for reducing odor of a herbicide. The method includes providing an effective quantity of the improved nonionic surfactant blend for combination with the herbicide.

GEDNALSKE JOE V; HERZFELD ROBERT W

346

Analysis of the stable carbon isotope composition of formic and acetic acids.  

UK PubMed Central (United Kingdom)

Formic and acetic acids are ubiquitous in the environment and in many biological processes. Analysis of the stable carbon isotope composition (?(13)C) of formic and acetic acids is important to understanding their biogeochemical cycles. However, it has been faced with poor accuracy and high detection limits due to their low carbon number, high hydrophilicity, and semi-volatility. Here we developed an analytical technique by needle trap and gas chromatography-isotope ratio mass spectrometry (GC-IRMS). The organic acids in aqueous solution were extracted using a NeedlEx needle through purge-and-trap and were analyzed by GC-IRMS for ?(13)C. The procedures incur no isotope fractionation. Defined as the point at which the mean ?(13)C is statistically the same as the given value and the analytical error starts rising, the method's detection limits are 200 and 100 mg/L for formic and acetic acids, respectively, with an uncertainty of approximately 0.5‰ in direct extraction and analysis. They were lowered to 1 mg/L with precision of 0.9‰ after samples were subjected to preconcentration. The method was successfully applied to natural samples as diverse as precipitation, vinegars, ant plasma, and vehicle exhaust, which vary considerably in concentration and matrix of the organic acids. It is applicable to the organic acids in not only aqueous solution but also gaseous phase.

Lee X; Zhang L; Huang D; An N; Yang F; Jiang W; Fang B

2013-05-01

347

Determination of ethanol in acetic acid-containing samples by a biosensor based on immobilized Gluconobacter cells  

Directory of Open Access Journals (Sweden)

Full Text Available Reshetilov AN, Kitova AE, Arkhipova AV, Kratasyuk VA, Rai MK. 2012. Determination of ethanol in acetic acid containing samples by a biosensor based on immobilized Gluconobacter cells. Nusantara Bioscience 4: 97-100. A biosensor based on Gluconobacter oxydans VKM B-1280 bacteria was used for detection of ethanol in the presence of acetic acid. It was assumed that this assay could be useful for controlling acetic acid production from ethanol and determining the final stage of the fermentation process. Measurements were made using a Clark electrode-based amperometric biosensor. The effect of pH of the medium on the sensor signal and the analytical parameters of the sensor (detection range, sensitivity) were investigated. The residual content of ethanol in acetic acid samples was analyzed. The results of the study are important for monitoring the acetic acid production process, as they represent a method of tracking its stages

ANATOLY N. RESHETILOV; ANNA E. KITOVA; ALENA V. ARKHIPOVA; VALENTINA A. KRATASYUK; MAHENDRA RAI

2012-01-01

348

Extraction and sorption of acetic acid at pH above pK{sub a} to form calcium magnesium acetate  

Energy Technology Data Exchange (ETDEWEB)

The use of rock salt for deicing roads has many negative effects on automobiles, highway systems, and the environment. Calcium magnesium acetate, hence-forth denoted CMA, has been identified as a more desirable, environmentally benign solid deicer for high-ways, airport runaways, and similar applications. CMA is also of interest as an additive for scavenging sulfur in combustion processes so as to reduce emissions of sulfur oxides and as a catalyst for coal gasification. Different extractants (trioctylphosphine oxide and secondary, tertiary, and quaternary amines) and solid sorbents (tertiary and quaternary amines) were investigated as agents for recovery of acetic acid as part of a process for production of CMA from fermentation acetic acid. The pH and temperature dependencies for uptake of acetic acid by these extractants and sorbents were measured, along with the degrees of regeneration by aqueous suspensions of slaked dolomitic lime. These results enable identification of agents having optimal basicity. Among the extractants, the secondary amine Amberlite LA-2 gave the best combined performance for extraction and regeneration. Among the sorbents, a tertiary amine, Amberlite IRA-35, gave the best performance. Trioctylphosphine oxide does not maintain capacity in the pH range (about 6) most attractive for acetic acid fermentation. Slurred crushed dolomite is not sufficiently basic to accomplish regeneration.

Reisinger, H.; King, C.J. [Lawrence Berkeley Lab., CA (United States)

1995-03-01

349

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

350

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

351

Enhanced biofuel production through coupled acetic acid and xylose consumption by engineered yeast.  

UK PubMed Central (United Kingdom)

The anticipation for substituting conventional fossil fuels with cellulosic biofuels is growing in the face of increasing demand for energy and rising concerns of greenhouse gas emissions. However, commercial production of cellulosic biofuel has been hampered by inefficient fermentation of xylose and the toxicity of acetic acid, which constitute substantial portions of cellulosic biomass. Here we use a redox balancing strategy to enable efficient xylose fermentation and simultaneous in situ detoxification of cellulosic feedstocks. By combining a nicotinamide adenine dinucleotide (NADH)-consuming acetate consumption pathway and an NADH-producing xylose utilization pathway, engineered yeast converts cellulosic sugars and toxic levels of acetate together into ethanol under anaerobic conditions. The results demonstrate a breakthrough in making efficient use of carbon compounds in cellulosic biomass and present an innovative strategy for metabolic engineering whereby an undesirable redox state can be exploited to drive desirable metabolic reactions, even improving productivity and yield.

Wei N; Quarterman J; Kim SR; Cate JH; Jin YS

2013-01-01

352

[Conversion of acetic acid to methane by thermophiles]. Progress report, May 15, 1989--May 14, 1993  

Energy Technology Data Exchange (ETDEWEB)

The primary goal of this project is to obtain a better understanding of thermophilic microorganisms which convert acetic acid to CH{sub 4}. The previous funding period represents a departure from earlier research in this laboratory, which was more physiological and ecological. The present work is centered on the biochemistry of the thermophile Methanothrix sp. strain CALS-1. this organism presents a unique opportunity, with its purity and relatively rapid growth, to do comparative biochemical studies with the other major acetotrophic genus Methanosarcina. We previously found that Methanothrix is capable of using acetate at concentrations 100 fold lower than Methanosarcina. This finding suggests that there are significant differences in the pathways of methanogenesis from acetate in the two genera.

Zinder, S.H.

1993-06-01

353

Synthesis and Antiradical/Antioxidant Activities of Caffeic Acid Phenethyl Ester and Its Related Propionic, Acetic, and Benzoic Acid Analoguesc  

Directory of Open Access Journals (Sweden)

Full Text Available Caffeic acid phenethyl ester (CAPE) is a bioactive component isolated from propolis. A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed. The effect of the presence of the double bond and of the conjugated system on the antioxidant effect is evaluated with the analogues obtained from 3-(3,4-dihydroxyphenyl) propanoic acid. Those obtained from 2-(3,4-dihydroxyphenyl) acetic acid and 3,4-dihydroxybenzoic acid allow the evaluation of the effect of the presence of two carbons between the carbonyl and aromatic system.

Luc M. LeBlanc; Aurélie F. Paré; Jacques Jean-François; Martin J. G. Hébert; Marc E. Surette; Mohamed Touaibia

2012-01-01

354

Removal of radium from sand filters by inorganic acids  

International Nuclear Information System (INIS)

Sand filters are used in water treatment stations to remove particulate matter from underground water, where iron and manganese are collected forming thin oxide films. These oxides of iron and manganese adsorb radium from underground water. Radium concentration increases in time on the filters, and consequently the level of radioactivity increases in the station. The removal of adsorbed radium on sand using inorganic acids was studied. Good efficiency of radium removal was obtained by controlling different parameters like temperature, time, pH, addition of competitive cations and anions. It was found that hydrochloric acid is the best for radium removal from sand filters. Maximum removal obtained was about 60% at 5M BaCl2 and 2M HCl at 50 deg C for 180-minute contact time. Kinetic parameters of the removal process were studied and compared with literature data. (author)

2006-01-01

355

Iron Dissolution of Dust Source Materials during Simulated Acidic Processing: The Effect of Sulfuric, Acetic, and Oxalic Acids.  

UK PubMed Central (United Kingdom)

Atmospheric organic acids potentially display different capacities in iron (Fe) mobilization from atmospheric dust compared with inorganic acids, but few measurements have been made on this comparison. We report here a laboratory investigation of Fe mobilization of coal fly ash, a representative Fe-containing anthropogenic aerosol, and Arizona test dust, a reference source material for mineral dust, in pH 2 sulfuric acid, acetic acid, and oxalic acid, respectively. The effects of pH and solar radiation on Fe dissolution have also been explored. The relative capacities of these three acids in Fe dissolution are in the order of oxalic acid > sulfuric acid > acetic acid. Oxalate forms mononuclear bidentate ligand with surface Fe and promotes Fe dissolution to the greatest extent. Photolysis of Fe-oxalate complexes further enhances Fe dissolution with the concomitant degradation of oxalate. These results suggest that ligand-promoted dissolution of Fe may play a more significant role in mobilizing Fe from atmospheric dust compared with proton-assisted processing. The role of atmospheric organic acids should be taken into account in global-biogeochemical modeling to better access dissolved atmospheric Fe deposition flux at the ocean surface.

Chen H; Grassian VH

2013-09-01

356

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; Ommee Benjama

2007-01-01

357

Removal of acidic or basic ?-amino acids in water by poorly water soluble scandium complexes.  

Science.gov (United States)

To recognize ?-amino acids with highly polar side chains in water, poorly water soluble scandium complexes with both Lewis acidic and basic portions were synthesized as artificial receptors. A suspension of some of these receptor molecules in an ?-amino acid solution could remove acidic and basic ?-amino acids from the solution. The compound most efficient at preferentially removing basic ?-amino acids (arginine, histidine, and lysine) was the receptor with 7,7'-[1,3-phenylenebis(carbonylimino)]bis(2-naphthalenesulfonate) as the ligand. The neutral ?-amino acids were barely removed by these receptors. Removal experiments using a mixed amino acid solution generally gave results similar to those obtained using solutions containing a single amino acid. The results demonstrated that the scandium complex receptors were useful for binding acidic and basic ?-amino acids. PMID:23050492

Hayashi, Nobuyuki; Jin, Shigeki; Ujihara, Tomomi

2012-10-10

358

Removal of acidic or basic ?-amino acids in water by poorly water soluble scandium complexes.  

UK PubMed Central (United Kingdom)

To recognize ?-amino acids with highly polar side chains in water, poorly water soluble scandium complexes with both Lewis acidic and basic portions were synthesized as artificial receptors. A suspension of some of these receptor molecules in an ?-amino acid solution could remove acidic and basic ?-amino acids from the solution. The compound most efficient at preferentially removing basic ?-amino acids (arginine, histidine, and lysine) was the receptor with 7,7'-[1,3-phenylenebis(carbonylimino)]bis(2-naphthalenesulfonate) as the ligand. The neutral ?-amino acids were barely removed by these receptors. Removal experiments using a mixed amino acid solution generally gave results similar to those obtained using solutions containing a single amino acid. The results demonstrated that the scandium complex receptors were useful for binding acidic and basic ?-amino acids.

Hayashi N; Jin S; Ujihara T

2012-11-01

359

Novel wine yeast with mutations in YAP1 that produce less acetic acid during fermentation.  

Science.gov (United States)

Acetic acid, a byproduct formed during yeast alcoholic fermentation, is the main component of volatile acidity (VA). When present in high concentrations in wine, acetic acid imparts an undesirable 'vinegary' character that results in a significant reduction in quality and sales. Previously, it has been shown that saké yeast strains resistant to the antifungal cerulenin produce significantly lower levels of VA. In this study, we used a classical mutagenesis method to isolate a series of cerulenin-resistant strains, derived from a commercial diploid wine yeast. Four of the selected strains showed a consistent low-VA production phenotype after small-scale fermentation of different white and red grape musts. Specific mutations in YAP1, a gene encoding a transcription factor required for oxidative stress tolerance, were found in three of the four low-VA strains. When integrated into the genome of a haploid wine strain, the mutated YAP1 alleles partially reproduced the low-VA production phenotype of the diploid cerulenin-resistant strains, suggesting that YAP1 might play a role in (regulating) acetic acid production during fermentation. This study offers prospects for the development of low-VA wine yeast starter strains that could assist winemakers in their effort to consistently produce wine to definable quality specifications. PMID:23146134

Cordente, Antonio G; Cordero-Bueso, Gustavo; Pretorius, Isak S; Curtin, Christopher D

2012-11-12

360

The potential of ¹¹C-acetate PET for monitoring the Fatty acid synthesis pathway in Tumors.  

UK PubMed Central (United Kingdom)

Positron emission tomography (PET) is a molecular imaging modality that provides the opportunity to rapidly and non-invasively visualize tumors derived from multiple organs. In order to do so, PET utilizes radiotracers, such as ¹?F-FDG and ¹¹C-acetate, whose uptake coincides with altered metabolic pathways within tumors. Increased expression and activity of enzymes in the fatty acid synthesis pathway is a frequent hallmark of cancer cells. As a result, this pathway has become a prime target for therapeutic intervention. Although multiple drugs have been developed that both directly and indirectly interfere with fatty acid synthesis, an optimal means to assess their efficacy is lacking. Given that ¹¹Cacetate is directly linked to the fatty acid synthesis pathway, this probe provides a unique opportunity to monitor lipogenic tumors by PET. Herein, we review the relevance of the fatty acid synthesis pathway in cancer. Furthermore, we address the potential utility of ¹¹C-acetate PET in imaging tumors, especially those that are not FDG-avid. Last, we discuss several therapeutic interventions that could benefit from ¹¹C-acetate PET to monitor therapeutic response in patients with certain types of cancers.

Deford-Watts LM; Mintz A; Kridel SJ

2013-03-01

 
 
 
 
361

Novel wine yeast with mutations in YAP1 that produce less acetic acid during fermentation.  

UK PubMed Central (United Kingdom)

Acetic acid, a byproduct formed during yeast alcoholic fermentation, is the main component of volatile acidity (VA). When present in high concentrations in wine, acetic acid imparts an undesirable 'vinegary' character that results in a significant reduction in quality and sales. Previously, it has been shown that saké yeast strains resistant to the antifungal cerulenin produce significantly lower levels of VA. In this study, we used a classical mutagenesis method to isolate a series of cerulenin-resistant strains, derived from a commercial diploid wine yeast. Four of the selected strains showed a consistent low-VA production phenotype after small-scale fermentation of different white and red grape musts. Specific mutations in YAP1, a gene encoding a transcription factor required for oxidative stress tolerance, were found in three of the four low-VA strains. When integrated into the genome of a haploid wine strain, the mutated YAP1 alleles partially reproduced the low-VA production phenotype of the diploid cerulenin-resistant strains, suggesting that YAP1 might play a role in (regulating) acetic acid production during fermentation. This study offers prospects for the development of low-VA wine yeast starter strains that could assist winemakers in their effort to consistently produce wine to definable quality specifications.

Cordente AG; Cordero-Bueso G; Pretorius IS; Curtin CD

2013-02-01

362

Kolbe electrolysis of acetic acid in a polymer electrolyte membrane reactor  

Energy Technology Data Exchange (ETDEWEB)

A polymer electrolyte membrane (PEM) reactor is described for use in Kolbe electrolysis: the anodic oxidation of an alkyl carboxylic acid with subsequent decarboxylation and coupling to yield a dimer, 2RCOOH {r_arrow} R-R + 2CO{sub 2} + 2e{sup {minus}} + 2H{sup +}. Platinized Nafion 117 is the PEM and functions simultaneously as the electrolyte and separator. Results demonstrating the feasibility of Kolbe electrolysis in a PEM reactor are presented for the oxidation of gaseous acetic acid (in a nitrogen diluent) to ethane and carbon dioxide, with hydrogen evolution at the counter electrode. The investigation includes the following effects on current density, current efficiency, and product selectivity: acetic acid partial pressure (P{sub total} {approx} 1 atm), cell voltage and temperature, phase of the catholyte (liquid water or humidified nitrogen), and the procedure used to prepare the membrane-electrode assembly. Current densities from 0.06 to 0.4 A/cm{sup 2} with Kolbe current efficiencies of 10 to 90% were obtained for cell voltages ranging from 4 to 10 V. The best results were obtained using PEMs platinized by a nonequilibrium impregnation-reduction method; a 75% current efficiency at 0.3 A/cm{sup 1} with a cell voltage of 6 V were measured at the following reaction conditions: 42 C reactor, 58 mm Hg acetic acid (50 C acetic acid dew point), and 42 C liquid water to the cathode. These initial results are encouraging for Kolbe electrolysis in a PEM cell; additional work, however, is needed to determine if the PEM strategy may be employed using a liquid-phase reactant. In addition, optimal reaction conditions and downstream mass-transfer separation requirements remain to be determined, both of which are reactant specific.

Hicks, M.T.; Fedkiw, P.S. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Chemical Engineering

1998-11-01

363

Dynamics of three organic acids (malic, acetic and succinic acid) in sunflower exposed to cadmium and lead.  

Science.gov (United States)

Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg x L(-1) Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb10 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely. PMID:23819268

Niu, Zhixin; Li, Xiaodong; Sun, Lina; Sun, Tieheng

2013-01-01

364

Dynamics of three organic acids (malic, acetic and succinic acid) in sunflower exposed to cadmium and lead.  

UK PubMed Central (United Kingdom)

Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg x L(-1) Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb10 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely.

Niu Z; Li X; Sun L; Sun T

2013-01-01

365

Main and interaction effects of acetic acid, furfural, and p-hydroxybenzoic acid on growth and ethanol productivity of yeasts  

Energy Technology Data Exchange (ETDEWEB)

The influence of the factors acetic acid, furfural, and p-hydroxybenzoic acid on the ethanol yield (Y{sub EtOH}) of Saccharomyces cerevisiae, bakers` yeast, S. cerevisiae ATCC 96581, and Candida shehatae NJ 23 was investigated using a 2{sup 3}-full factorial design with 3 centerpoints. The results indicated that acetic acid inhibited the fermentation by C. shehatae NJ 23 markedly more than by bakers` yeast, whereas no significant difference in tolerance towards the compounds was detected between the S. cerevisiae strains. Furfural and the lignin derived compound p-hydroxybenzoic acid did not affect any of the yeasts at the cell mass concentration used. The results indicated that the linear model was not adequate to describe the experimental data. Based on the results from the 2{sup 3}-full factorial experiment, an extended experiment was designed based on a central composite design to investigate the influence of the factors on the specific growth rate ({mu}), biomass yield (Y{sub x}), volumetric ethanol productivity (Q{sub EtOH}), and Y{sub EtOH}. Bakers` yeast was chosen in the extended experiment due to its better tolerance towards acetic acid, which makes it a more interesting organism for use in industrial fermentations of lignocellulosic hydrolysates.

Palmqvist, E.; Grage, H.; Meinander, N.Q.; Hahn-Haegerdal, B. [Univ. of Lund (Sweden)

1999-04-05

366

The role of glass composition in the behaviour of glass acetic acid and glass lactic acid cements.  

Science.gov (United States)

Cements have recently been described, made from glass ionomer glass reacted with acetic and lactic acid instead of polymeric carboxylic acid. From their behaviour a theory relating to a possible secondary setting mechanism of glass ionomer has been adduced. However, only one glass (G338) was used throughout. In this study a much simpler glass ionomer glass (MP4) was compared with G338. This produced very different results. With acetic acid G338 formed cement which became resistant to water over a period of hours, as previously reported, MP4 formed cement which was never stable to water. With lactic acid G338 behaved similarly to G338 with acetic acid, again as reported, but MP4 produced a cement which was completely resistant to water at early exposure and unusually became slightly less resistant if exposure was delayed for 6 h or more. These findings indicate that the theories relating to secondary setting in glass ionomer maturation may need revision. PMID:17619992

Shahid, Saroash; Billington, R W; Pearson, G J

2007-07-10

367

Anodic generation of cerium(IV) at glassy carbon in acetic acid and coulometric titrations with the generated reagent  

International Nuclear Information System (INIS)

Conditions for electrochemical generation of cerium(IV) at glassy carbon in acetic acid in the presence of alkali-metal acetates and sodium perchlorate, respectively, were investigated. A high current efficiency was achieved in anodic oxidation of cerium(III) in acetate supporting electrolytes. Coulometric titration methods for the determination of reducing substances with the generated oxidant were also developed. The end-points were determined by the biamperometric and bipotentiometric methods. The error of the determinations was less than ± 2%.

1993-01-01

368

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

1146-01-00

369

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 2.5–50 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

370

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

UK PubMed Central (United Kingdom)

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 O-H···O and intramolecular C-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 SD; Balachandran S

2013-05-01

371

Synthesis of 2, 4-- dichloro phenoxy acetic acid [ Carboxy- 14 C] as herbicide  

International Nuclear Information System (INIS)

[en] One of the important herbicide, that can be used for the practical mechanism investigations and studies of metabolism functions of different plants is 2,4 dichlorophenoxy acetic acid compound. In this article, the production method for labeling the titled compound is explained. At the first stage of this research work, barium[14C] carbonate is converted into potassium [14C] by using potassium azid at a reasonable temperature. Then, after a few synthesis reaction, the compound 2,4 dichlorophenoxy methyl iodide is produced via 2,4 dichlorophenoxy as a starting material. At the next stage, the real material as a herbicide: 2,4 dichlorophenoxy acetic acid [carboxy- 14C] is prepared and produced, by the coupling reaction between 2,4 dichlorophenoxy methyl iodide and potassium [14C] cyanide, and then the resulting nitrile has been hydrolyzed

2005-01-01

372

Preparation and preservation of freeze-dried cells of acetic acid bacteria with aldehyde oxidase activity.  

UK PubMed Central (United Kingdom)

Freeze-dried cells of acetic acid bacteria were prepared to use as an additive for manufacturing and processing foods. When the freeze-dried cells were stored for 1 week at 5 degrees C, however, more than 50% of the original activity of aldehyde oxidase (AOX) was lost. It was found that this decrease in AOX was caused by damage to both the membrane-bound aldehyde dehydrogenase and terminal oxidase activities involved in the aldehyde oxidase electron transport system of acetic acid bacteria. The addition of 30% sucrose to the cell suspension prepared in a McIlvaine buffer (pH 6) before lyophilization was found to be effective for preventing the decrease of AOX activity. Cells freeze-dried in this way lost no AOX activity at all during first 3 weeks of storage at 5 degrees C and, even after 9 weeks, 80% of the original activity remained.

Nomura Y; Yamamoto M; Matsushita K; Kumagai H

1998-06-01

373

Preparation and preservation of freeze-dried cells of acetic acid bacteria with aldehyde oxidase activity.  

Science.gov (United States)

Freeze-dried cells of acetic acid bacteria were prepared to use as an additive for manufacturing and processing foods. When the freeze-dried cells were stored for 1 week at 5 degrees C, however, more than 50% of the original activity of aldehyde oxidase (AOX) was lost. It was found that this decrease in AOX was caused by damage to both the membrane-bound aldehyde dehydrogenase and terminal oxidase activities involved in the aldehyde oxidase electron transport system of acetic acid bacteria. The addition of 30% sucrose to the cell suspension prepared in a McIlvaine buffer (pH 6) before lyophilization was found to be effective for preventing the decrease of AOX activity. Cells freeze-dried in this way lost no AOX activity at all during first 3 weeks of storage at 5 degrees C and, even after 9 weeks, 80% of the original activity remained. PMID:9692195

Nomura, Y; Yamamoto, M; Matsushita, K; Kumagai, H

1998-06-01

374

Dynamics of indole-3-acetic acid during germination of Picea abies seeds.  

UK PubMed Central (United Kingdom)

High performance liquid chromatography and combined gas chromatography-mass spectrometry were used to identify indole-3-acetic acid (IAA) and indole-3-ethanol as endogenous constituents of germinating Norway spruce (Picea abies (L.) Karst.) seeds. Indole-3-methanol was tentatively identified by multiple ion monitoring. The free IAA content of the seeds rose from about 20 ng g(-1) to about 60 ng g(-1) (dry weight) during the first five days of germination and thereafter declined to around 20 ng g(-1). Indole-3-acetic acid released by alkaline hydrolysis, which was initially present at about 110 ng g(-1), decreased to 5-10 ng g(-1) during the first week of germination. The IAA content of seed lots differing in germination behavior was investigated. The findings are discussed in relation to the metabolism of IAA in conifer seeds.

Sandberg G; Ernstsen A

1987-06-01

375

Dynamics of indole-3-acetic acid during germination of Picea abies seeds.  

Science.gov (United States)

High performance liquid chromatography and combined gas chromatography-mass spectrometry were used to identify indole-3-acetic acid (IAA) and indole-3-ethanol as endogenous constituents of germinating Norway spruce (Picea abies (L.) Karst.) seeds. Indole-3-methanol was tentatively identified by multiple ion monitoring. The free IAA content of the seeds rose from about 20 ng g(-1) to about 60 ng g(-1) (dry weight) during the first five days of germination and thereafter declined to around 20 ng g(-1). Indole-3-acetic acid released by alkaline hydrolysis, which was initially present at about 110 ng g(-1), decreased to 5-10 ng g(-1) during the first week of germination. The IAA content of seed lots differing in germination behavior was investigated. The findings are discussed in relation to the metabolism of IAA in conifer seeds. PMID:14975830

Sandberg, G; Ernstsen, A

1987-06-01

376

Halogenated indole-3-acetic acids as oxidatively activated prodrugs with potential for targeted cancer therapy.  

UK PubMed Central (United Kingdom)

Substituted indole-3-acetic acid (IAA) derivatives, plant auxins with potential for use as prodrugs in enzyme-prodrug directed cancer therapies, were oxidised with horseradish peroxidase (HRP) and toxicity against V79 Chinese hamster lung fibroblasts was determined. Rate constants for oxidation by HRP compound I were also measured. Halogenated IAAs were found to be the most cytotoxic, with typical surviving fractions of <10(-3) after incubation for 2h with 100 microM prodrug and HRP.

Rossiter S; Folkes LK; Wardman P

2002-09-01

377

Radiation heterogeneous processes of 14C-acetic acid adsorbed in Na-Montmorillonite  

International Nuclear Information System (INIS)

This research addresses itself to the study of the mechanism of the acetic acid decarboxylation in Na-Montmorillonite exposed to ionizing radiation. The results obtained indicated that the decarboxylation reaction is enhanced several times by the irradiation. This behavior is probably due to an oxidation reaction at the edges of the clay. Also it is by energy transfer from the clay to adsorbed molecules by an interaction of non-equilibrium charge carriers with the adsorbed molecules. (author) 9 refs.; 1 tab.

1992-01-01

378

Oxidation of ethane to ethylene and acetic acid by MoVNbO catalysts  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The influence of niobium on the physicochemical properties of the Mo-V-O system and on its catalytic properties in the oxidation of ethane to ethylene and acetic acid is examined. Solids based on MoV0.4Ox and MoV0.4Nb0.12Oy composition and calcined at 350 or 400°C were studied by X-ray diffraction, ...

Roussel, Martial; Bouchard, Michel; Bordes-Richard, Elisabeth; Karim, Khalid; Al-Sayari, Saleh

379

1-[3-(4-Nitro­phen­yl)propano­yl]urea acetic acid monosolvate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The title compound, C10H11N3O4·C2H4O2, was prepared by an electrochemical technique. In the crystal, acetic acid mol­ecules are involved in hydrogen bonding to two separate propano­ylurea mol­ecules, acting as a donor in an O—H?O inter­action and as an acceptor in two N—H?O inter­actions. The propan...

Merzouki, Soraya; Mouats, Chabane; Bendeif, El-Eulmi; Pillet, Sebastien; Bouchouit, Karim

380

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; NELSON NAINGGOLAN

2006-01-01

 
 
 
 
381

N-(7-Methyl-1,8-naphthyridin-2-yl)acetamide–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; Rui Ma; Qing-Di Zhou; Shao-Ming Chi

2013-01-01

382

Study of acetic acid production by immobilized acetobacter cells: oxygen transfer  

Energy Technology Data Exchange (ETDEWEB)

The immobilization of living Acetobacter cells by adsorption onto a large-surface-area ceramic support was studied in a pulsed flow reactor. The high oxygen transfer capability of the reactor enabled acetic acid production rates up to 10.4 g/L/h to be achieved. Using a simple mathematical model incorporating both internal and external mass transfer coefficients, it was shown that oxygen transfer in the microbial film controls the reactor productivity. (Refs. 10).

Ghommidh, C.; Navarro, J.M.; Durand, G.

1982-03-01

383

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals.  

Science.gov (United States)

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 treatment plants, demonstrated considerably higher removal rates per unit biomass (i.e. suspended solids for the sludges and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast to the pharmaceutical removal, the nitrification capacity per unit biomass was lower for the carriers than the sludges, which suggests that neither the nitrite nor the ammonia oxidizing bacteria are primarily responsible for the observed differences in pharmaceutical removal. The low ability of ammonia oxidizing bacteria to degrade or transform the target pharmaceuticals was further demonstrated by the limited pharmaceutical removal in an experiment with continuous nitritation and biofilm carriers from a partial nitritation/anammox sludge liquor treatment process. PMID:22209263

Falås, P; Baillon-Dhumez, A; Andersen, H R; Ledin, A; la Cour Jansen, J

2011-12-11

384

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals.  

UK PubMed Central (United Kingdom)

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 treatment plants, demonstrated considerably higher removal rates per unit biomass (i.e. suspended solids for the sludges and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast to the pharmaceutical removal, the nitrification capacity per unit biomass was lower for the carriers than the sludges, which suggests that neither the nitrite nor the ammonia oxidizing bacteria are primarily responsible for the observed differences in pharmaceutical removal. The low ability of ammonia oxidizing bacteria to degrade or transform the target pharmaceuticals was further demonstrated by the limited pharmaceutical removal in an experiment with continuous nitritation and biofilm carriers from a partial nitritation/anammox sludge liquor treatment process.

Falås P; Baillon-Dhumez A; Andersen HR; Ledin A; la Cour Jansen J

2012-03-01

385

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals  

DEFF Research Database (Denmark)

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 treatment plants, demonstrated considerably higher removal rates per unit biomass (i.e. suspended solids for the sludges and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast to pharmaceutical removal, the nitrification capacity per unit biomass was lower for the carriers than the sludges, which suggests that neither the nitrite nor the ammonia oxidizing bacteria are primarily responsible for the observed differences in pharmaceutical removal. The low ability of ammonia oxidizing bacteria to degrade or transform the target pharmaceuticals was further demonstrated by the limited pharmaceutical removal in an experiment with continuous nitritation and biofilm carriers from a partial nitritation/anammox sludge liquor treatment process.

Falås, Per; Baillon-Dhumez, Aude

2012-01-01

386

Removal of trace contaminants from recycle nitric acid  

Energy Technology Data Exchange (ETDEWEB)

Extensive recycle of nitric acid and water in a nuclear fuel reprocessing plant can result in the build-up of deleterious trace impurities; identified materials of serious concern include fluoride, chloride, and organic materials. Methods for removal of these deleterious materials must be developed to allow increased aqueous recycle. Fluoride at 10 to 100 /mu/g/ml can be removed from 10 M HNO/sub 3/ using a silica gel column. Chloride can be removed from 10 M HNO/sub 3/ by sparging with ozonized air, a method that is rapid even at room temperature. Carbonaceous material can be removed by pressurized aqueous combustion and by ozonation. 11 refs.

Clark, W.E.; Howerton, W.B.; Mailen, J.C.

1981-05-01

387

Reductions of aldehydes and ketones with a readily available N-heterocyclic carbene borane and acetic acid.  

UK PubMed Central (United Kingdom)

Acetic acid promotes the reduction of aldehydes and ketones by the readily available N-heterocyclic carbene borane, 1,3-dimethylimidazol-2-ylidene borane. Aldehydes are reduced over 1-24 h at room temperature with 1 equiv of acetic acid and 0.5 equiv of the NHC-borane. Ketone reductions are slower but can be accelerated by using 5 equiv of acetic acid. Aldehydes can be selectively reduced in the presence of ketones. On a small scale, products are isolated by evaporation of the reaction mixture and direct chromatography.

Lamm V; Pan X; Taniguchi T; Curran DP

2013-01-01

388

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

389

Exponential drop of radiocesium activity in mushrooms due to the effect of acetic acid  

UK PubMed Central (United Kingdom)

The capability of vinegary pickle (2% solution of acetic acid) as a decontaminant for mushrooms has been studied. The complete sporocarps of Xerocomus badius, Suillus luteus and Lepista saeve in dry weight, the native state and after defrosting were investigated. The mushroom samples gathered in forest ecosystems were contaminated by the post-Chernobyl radiocesium. The activity concentrations of ¹³?Cs were determined by the semiconductor gammaspectroscopy. It was proved that the reduction in activity has been affected by the frequency of replacement of acetic acid. However, the number of replacements is limited due to a change of the mushroom consistency. The vinegary pickle is already effective after the first treatment, i.e. the activity in the dry weight was reduced by 73%, and in the native state by 59%. The radiocesium activity follows an exponential curve with the exponents of 0.766 (the dry weight with the values exceeding the maximum permissible level of contamination), 0.266 (the dry weight with low activities) and 0.040 (mushrooms in the native state with the activities near the maximum permissible level of contamination) for the repeated effect of the fresh solution of acetic acid.

Dvo?ák P; Kunová V; Be?ová K

2006-01-01

390

Energy metabolism of a unique acetic acid bacterium, Asaia bogorensis, that lacks ethanol oxidation activity.  

Science.gov (United States)

Acetic acid bacteria (AAB) are known as a vinegar producer on account of their ability to accumulate a high concentration of acetic acid due to oxidative fermentation linking the ethanol oxidation respiratory chain. Reactions in oxidative fermentation cause poor growth because a large amount of the carbon source is oxidized incompletely and the harmful oxidized products are accumulated almost stoichiometrically in the culture medium during growth, but a newly identified AAB, Asaia, has shown unusual properties, including scanty acetic acid production and rapid growth, as compared with known AAB as Acetobacter, Gluconobacter, and Gluconacetobacter. To understand these unique properties of Asaia in more detail, the respiratory chain and energetics of this strain were investigated. It was found that Asaia lacks quinoprotein alcohol dehydrogenase, but has other sugar and sugar alcohol-oxidizing enzymes specific to the respiratory chain of Gluconobacter, especially quinoprotein glycerol dehydrogenase. It was also found that Asaia has a cyanide-sensitive cytochrome bo(3)-type ubiquinol oxidase as sole terminal oxidase in the respiratory chain, and that it exhibits a higher H(+)/O ratio. PMID:18391448

Ano, Yoshitaka; Toyama, Hirohide; Adachi, Osao; Matsushita, Kazunobu

2008-04-07

391

Energy metabolism of a unique acetic acid bacterium, Asaia bogorensis, that lacks ethanol oxidation activity.  

UK PubMed Central (United Kingdom)

Acetic acid bacteria (AAB) are known as a vinegar producer on account of their ability to accumulate a high concentration of acetic acid due to oxidative fermentation linking the ethanol oxidation respiratory chain. Reactions in oxidative fermentation cause poor growth because a large amount of the carbon source is oxidized incompletely and the harmful oxidized products are accumulated almost stoichiometrically in the culture medium during growth, but a newly identified AAB, Asaia, has shown unusual properties, including scanty acetic acid production and rapid growth, as compared with known AAB as Acetobacter, Gluconobacter, and Gluconacetobacter. To understand these unique properties of Asaia in more detail, the respiratory chain and energetics of this strain were investigated. It was found that Asaia lacks quinoprotein alcohol dehydrogenase, but has other sugar and sugar alcohol-oxidizing enzymes specific to the respiratory chain of Gluconobacter, especially quinoprotein glycerol dehydrogenase. It was also found that Asaia has a cyanide-sensitive cytochrome bo(3)-type ubiquinol oxidase as sole terminal oxidase in the respiratory chain, and that it exhibits a higher H(+)/O ratio.

Ano Y; Toyama H; Adachi O; Matsushita K

2008-04-01

392

Evaluation of Cervical Biopsies Guided by Visual Inspection With Acetic Acid.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To evaluate the accuracy of visual inspection with acetic acid (VIA) in determining the site, the size, and the number of cervical biopsies in patients with positive cervical cytology. METHODS: This study included 486 patients with positive cervical cytology who presented to the Gynaecological Oncology Unit of Minia Maternity University Hospital, Egypt, in the period between January 2008 and September 2011. Visual inspection with acetic acid was done for all patients. They were classified into 2 groups according to the results of VIA. Group 1 included VIA-negative women, whereas group 2 included VIA-positive women. All patients were reexamined with colposcopy to prove or disprove the presence of lesions. Cervical biopsies were taken from patients with positive VIA or colposcopically confirmed lesions using punch biopsy forceps. Biopsies were sent for histologic examination. RESULTS: In group 1, 100 patients were VIA-negative, 66 of them were histopathologically free, whereas 34 patients had positive biopsy results. Group 2 included 386 patients: 31 were histologically free, 239 had cervical intraepithelial neoplasia (CIN) 1, whereas 116 had CIN 2 or worse. CONCLUSIONS: Visual inspection with acetic acid is a good test for aiding the diagnosis of CIN and may be helpful in determining the site, the size, and the number of biopsies in patients with positive cytologic results. Instead of colposcopy, VIA can be used in developing countries where colposcopic services are not available.

Sanad AS; Ibrahim EM; Gomaa W

2013-06-01

393

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

Directory of Open Access Journals (Sweden)

Full Text Available 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, Mass, IR, 1H NMR and 13C NMR and spectroscopic techniques. All the compounds were screened for their antioxidant activities by applying in vitro methods like 2,2-diphenyl-1-picryl hydrazyl (DPPH) free radical scavenging assay and inhibition of microsomal lipid peroxidation (LPO) assay. Butylated hydroxy anisole (BHA) was used as a reference antioxidant compound and the comparative study with newly synthesized compounds was also done. Among the analogues, compound 9 bearing electron donating methoxy substituent in addition to the phenolic moiety showed predominant activity. It is conceivable from these studies that the coupling of aniline and substituted anilines is the most important feature for the significant antioxidant activity of indole-3-acetic acid analogues studied.

Nagaraja Naik; Honnaiah Vijay Kumar; Salakatte Thammaiah Harini

2011-01-01

394

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

International Nuclear Information System (INIS)

[en] 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

395

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

396

Interaction of acetic acid and phenylacetaldehyde as attractants for trapping pest species of moths (Lepidoptera: Noctuidae).  

UK PubMed Central (United Kingdom)

BACKGROUND: Phenylacetaldehyde is a flower volatile and attractant for many nectar-seeking moths. Acetic acid is a microbial fermentation product that is present in insect sweet baits. It is weakly attractive to some moths and other insects, but can be additive or synergistic with other compounds to make more powerful insect lures. RESULTS: Acetic acid and phenylacetaldehyde presented together in traps made a stronger lure than either chemical alone for moths of the alfalfa looper Autographa californica (Speyer) and the armyworm Spodoptera albula (Walker). However, this combination of chemicals reduced captures of the cabbage looper moth Trichoplusia ni (Hübner), the silver Y moth Autographa gamma (L.), MacDunnoughia confusa (Stephens) and the soybean looper moth Chrysodeixis includens (Walker) by comparison with phenylacetaldehyde alone. CONCLUSION: These results indicate both positive and negative interactions of acetic acid, a sugar fermentation odor cue, and phenylacetaldehyde, a floral scent cue, in eliciting orientation responses of moths. This research provides a new two-component lure for the alfalfa looper A. californica and for the armyworm S. albula for potential use in pest management.

Landolt PJ; Tóth M; Meagher RL; Szarukán I

2013-02-01

397

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; Ritesh Kumar Jaiswal; Sudarshan Maurya; Udai Pratap Singh

2013-01-01

398

Relationships between the resistance of yeasts to acetic, propanoic and benzoic acids and to methyl paraben and pH.  

UK PubMed Central (United Kingdom)

Minimum inhibitory concentrations of acetic, propanoic and benzoic acids and methyl paraben were determined at pH 3.50 for 22 isolates of 11 yeast species, differing in their resistance to preservatives. Growth in the presence of benzoic acid enhanced the resistance of yeast