Identification of novel potential acetate-oxidizing bacteria in an acetate-fed methanogenic chemostat based on DNA stable isotope probing.

Science.gov (United States)

Wang, Hui-Zhong; Gou, Min; Yi, Yue; Xia, Zi-Yuan; Tang, Yue-Qin

2018-05-11

Acetate is a significant intermediate of anaerobic fermentation. There are two pathways for converting acetate to CH 4 and CO 2 : acetoclastic methanogenesis by acetoclastic methanogens, and syntrophic acetate oxidation by acetate-oxidizing bacteria (AOB) and hydrogenotrophic methanogens. Detailed investigations of syntrophic acetate-oxidizing bacteria (SAOB) should contribute to the elucidation of the microbial mechanisms of methanogenesis. In this study, we investigated the major phylogenetic groups of acetate-utilizing bacteria (AUB) in a mesophilic methanogenic chemostat fed with acetate as the sole carbon source by using DNA stable isotope probing (SIP) technology. The results indicated that acetoclastic methanogenesis and acetate oxidization/hydrogenotrophic methanogenesis coexisted in the mesophilic chemostat fed with acetate, operated at a dilution rate of 0.1 d -1 . OTU Ace13(9-17) (KU869530), Ace13(9-4) (KU667241), and Ace13(9-23) (KU667236), assigned to the phyla Firmicutes and Bacteroidetes, were probably potential SAOB in the chemostat, which needs further investigation. Species in the phyla Proteobacteria, Deferribacteres, Acidobacteria, Spirochaetes and Actinobacteria were probably capable of utilizing acetate for their growth. Methanoculleus was likely to be the preferred hydrogenotrophic methanogen for syntrophy with AOB in the chemostat.

Proton conductivity and relaxation properties of chitosan-acetate films

International Nuclear Information System (INIS)

Prokhorov, E.; Luna-Bárcenas, G.; González-Campos, J.B.; Kovalenko, Yu.; García-Carvajal, Z.Y.; Mota-Morales, J.

2016-01-01

Graphical abstract: Temperature dependence of conductivity, the number of density and proton mobility in chitosan-acetate film. - Highlights: • DD, conductivity, Vogel temperature dependent on the concentration of acetic acid. • Proton conductivity of CS-acetate films interpreted using two Grotthuss mechanisms. • Transformation between two mechanisms observed at the glass transition temperature. - Abstract: The effect of aqueous acetic acid solution concentration during the preparation of chitosan-acetate (CS-acetate) films on the conductivity and relaxation properties were studied by dielectric and FTIR spectroscopies, TGA measurements and X-Ray diffraction. Analyses of the experimental results on the degree of deacetylation, water absorption, conductivity, Vogel temperature and activation energy demonstrate a strong dependence of these parameters on the concentration of the acid acetic solutions from which the films have been obtained. The proton conductivity and relaxation properties of CS-acetate films have been interpreted using two Grotthuss “structural diffusion” and “pack-acid” mechanisms. The transformation between these two mechanisms observed at temperature higher than CS-acetate glass transition temperature is due to an increase in the thermal motion of CS chains, water evaporation, hydrogen bond between water molecules and side groups of CS breaking and formation of new bonds between NH 3 + and acetate ions. Additionally, application of the Rice and Roth model allowed estimating the temperature dependence of proton number and their mobility in CS-acetate films. A systematic interpretation on the appropriate conductivity mechanism will help trigger the design of smart materials used in flexible electronic, solid polymer electrolytes for fuel cells and solid polymer batteries based on CS-acetate films.

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

Directory of Open Access Journals (Sweden)

VALENTINA A. KRATASYUK

2012-11-01

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

78 FR 14095 - Determination That GEREF (Sermorelin Acetate) Injection, 0.5 Milligrams Base/Vial and 1.0...

Science.gov (United States)

2013-03-04

...] Determination That GEREF (Sermorelin Acetate) Injection, 0.5 Milligrams Base/Vial and 1.0 Milligrams Base/Vial, and GEREF (Sermorelin Acetate) Injection, 0.05 Milligrams Base/Amp, Were Not Withdrawn From Sale for...

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

Science.gov (United States)

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

2002-12-06

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

Ulipristal acetate versus leuprolide acetate for uterine fibroids.

Science.gov (United States)

Donnez, Jacques; Tomaszewski, Janusz; Vázquez, Francisco; Bouchard, Philippe; Lemieszczuk, Boguslav; Baró, Francesco; Nouri, Kazem; Selvaggi, Luigi; Sodowski, Krzysztof; Bestel, Elke; Terrill, Paul; Osterloh, Ian; Loumaye, Ernest

2012-02-02

The efficacy and side-effect profile of ulipristal acetate as compared with those of leuprolide acetate for the treatment of symptomatic uterine fibroids before surgery are unclear. In this double-blind noninferiority trial, we randomly assigned 307 patients with symptomatic fibroids and excessive uterine bleeding to receive 3 months of daily therapy with oral ulipristal acetate (at a dose of either 5 mg or 10 mg) or once-monthly intramuscular injections of leuprolide acetate (at a dose of 3.75 mg). The primary outcome was the proportion of patients with controlled bleeding at week 13, with a prespecified noninferiority margin of -20%. Uterine bleeding was controlled in 90% of patients receiving 5 mg of ulipristal acetate, in 98% of those receiving 10 mg of ulipristal acetate, and in 89% of those receiving leuprolide acetate, for differences (as compared with leuprolide acetate) of 1.2 percentage points (95% confidence interval [CI], -9.3 to 11.8) for 5 mg of ulipristal acetate and 8.8 percentage points (95% CI, 0.4 to 18.3) for 10 mg of ulipristal acetate. Median times to amenorrhea were 7 days for patients receiving 5 mg of ulipristal acetate, 5 days for those receiving 10 mg of ulipristal acetate, and 21 days for those receiving leuprolide acetate. Moderate-to-severe hot flashes were reported for 11% of patients receiving 5 mg of ulipristal acetate, for 10% of those receiving 10 mg of ulipristal acetate, and for 40% of those receiving leuprolide acetate (P<0.001 for each dose of ulipristal acetate vs. leuprolide acetate). Both the 5-mg and 10-mg daily doses of ulipristal acetate were noninferior to once-monthly leuprolide acetate in controlling uterine bleeding and were significantly less likely to cause hot flashes. (Funded by PregLem; ClinicalTrials.gov number, NCT00740831.).

Development of Biocomposites with Antioxidant Activity Based on Red Onion Extract and Acetate Cellulose

Directory of Open Access Journals (Sweden)

Carol López de Dicastillo

2015-08-01

Full Text Available Antioxidant biocomposites have been successfully developed from cellulose acetate, eco-friendly triethyl citrate plasticizer and onion extract as a source of natural antioxidants. First, an onion extraction process was optimized to obtain the extract with highest antioxidant power. Extracts under absolute ethanol and ethanol 85% were the extracts with the highest antioxidant activity, which were the characterized through different methods, DPPH (2,2-diphenyl-1-picrylhydrazyl and ABTS (2,2ʹ-azinobis(3-ethylbenzothiazoline-6-sulphonate, that measure radical scavenger activity, and polyphenolic and flavonoid content. Afterwards, the extract was incorporated in cellulose acetate as polymer matrix owing to develop an active material intended to oxidative sensitive food products packaging. Different concentrations of onion extract and plasticizer were statistically studied by using response surface methodology in order to analyze the influence of both factors on the release of active compounds and therefore the antioxidant activity of these materials.

Improved adaptation of test with lanthanum nitrate for the colorimetric estimation of acetate

Energy Technology Data Exchange (ETDEWEB)

Szumilo, T [Akademia Medyczna, Lublin (Poland)

1976-01-01

A colorimetric method for the determination of acetate based on the production of the blue complex between iodine and lanthanum alkaline acetate has been developed. Optimum concentrations of reagents (acetate, lanthanum nitrate, iodine and ammonia) as well as the volume of acetate were selected to achieve best colour intensity. Coloured complex was stabilized by dilution of reagent mixture with water to the final volume convenient for determinaton. Absorbance of the complex can be measured immediately after dilution and any changes can be observed during at least 15 minutes. Elevation of temperature over 60/sup 0/decreases absorbance. The method fulfills the Beer's law in the range 1,5-3,5 ..mu..moles of acetate, precision of the method 2/sup +/ = 3,7%. Apart from acetate - propionate and fluoroacetate complex is 620 nm, propionate complex - at 590 nm. Propionate complex displayed any relationship between concentration and absorbance. Potassium, sodium, lithium and barium acetates give the identical results as acetic acid, whereas zinc and cupric acetates failed to react. Other derivatives tested, e.g. chloroacetate, trichloroacetate, iodoacetate, chloroporpionate and butyrate are unable to form the coloured complexes. Many compounds interfere with the formation of acetate complex, therefore, in material containing impurities acetate can be determined after purificaton by means of described in literature methods.

Biodegradable starch-based polymeric materials

Science.gov (United States)

Suvorova, Anna I.; Tyukova, Irina S.; Trufanova, Elena I.

2000-05-01

The effects of low-molecular-weight additives, temperature and mechanical action on the structure and properties of starch are discussed. Special attention is given to mixtures of starch with synthetic polymers, e.g., co-polymers of ethylene with vinyl acetate, vinyl alcohol, acrylic acid, cellulose derivatives and other natural polymers. These mixtures can be used in the development of novel environmentally safe materials (films, coatings, packaging materials) and various articles for short-term use. The bibliography includes 105 references.

Anion recognition using newly synthesized hydrogen bonding disubstituted phenylhydrazone-based receptors: poly(vinyl chloride)-based sensor for acetate.

Science.gov (United States)

Gupta, Vinod K; Goyal, Rajendra N; Sharma, Ram A

2008-08-15

A potentiometric acetate-selective sensor, based on the use of butane-2,3-dione,bis[(2,4-dinitrophenyl)hydrazone] (BDH) as a neutral carrier in poly(vinyl chloride) (PVC) matrix, is reported. Effect of various plasticizers and cation excluder, cetryaltrimethylammonium bromide (CTAB) was studied. The best performance was obtained with a membrane composition of PVC:BDH:CTAB ratio (w/w; mg) of 160:8:8. The sensor exhibits significantly enhanced selectivity toward acetate ions over a wide concentration range 5.0 x 10(-6) to 1.0 x 10(-1)M with a lower detection limit of 1.2 x 10(-6)M within pH range 6.5-7.5 with a response time of Fast and stable response, good reproducibility and long-term stability are demonstrated. The sensor has a response time of 15s and can be used for at least 65 days without any considerable divergence in their potential response. Selectivity coefficients determined with the separate solution method (SSM) and fixed interference method (FIM) indicate that high selectivity for acetate ion. The proposed electrode shows fairly good discrimination of acetate from several inorganic and organic anions. It was successfully applied to direct determination of acetate within food preservatives. Total concentration of acetic acid in vinegar samples were determined by direct potentiometry and the values agreed with those mentioned by the manufacturers.

Influence of an acetate- and a lactate-based balanced infusion solution on acid base physiology and hemodynamics: an observational pilot study.

Science.gov (United States)

Hofmann-Kiefer, Klaus F; Chappell, Daniel; Kammerer, Tobias; Jacob, Matthias; Paptistella, Michaela; Conzen, Peter; Rehm, Markus

2012-07-06

The current pilot study compares the impact of an intravenous infusion of Ringer's lactate to an acetate-based solution with regard to acid-base balance. The study design included the variables of the Stewart approach and focused on the effective strong ion difference. Because adverse hemodynamic effects have been reported when using acetate buffered solutions in hemodialysis, hemodynamics were also evaluated. Twenty-four women who had undergone abdominal gynecologic surgery and who had received either Ringer's lactate (Strong Ion Difference 28 mmol/L; n = 12) or an acetate-based solution (Strong Ion Difference 36.8 mmol/L; n = 12) according to an established clinical protocol and its precursor were included in the investigation. After induction of general anesthesia, a set of acid-base variables, hemodynamic values and serum electrolytes was measured three times during the next 120 minutes. Patients received a mean dose of 4,054 ± 450 ml of either one or the other of the solutions. In terms of mean arterial blood pressure and norepinephrine requirements there were no differences to observe between the study groups. pH and serum HCO3- concentration decreased slightly but significantly only with Ringer's lactate. In addition, the acetate-based solution kept the plasma effective strong ion difference more stable than Ringer's lactate. Both of the solutions provided hemodynamic stability. Concerning consistency of acid base parameters none of the solutions seemed to be inferior, either. Whether the slight advantages observed for the acetate-buffered solution in terms of stability of pH and plasma HCO3- are clinically relevant, needs to be investigated in a larger randomized controlled trial.

Electrospun phase change fibers based on polyethylene glycol/cellulose acetate blends

International Nuclear Information System (INIS)

Chen, Changzhong; Wang, Linge; Huang, Yong

2011-01-01

Highlights: → Ultrafine PEG/CA phase change fibers were fabricated by electrospinning. → PEG content dramatically influenced the fiber morphology and phase change behaviors. → The electrospun fibers have excellent thermal properties for thermal energy storage. - Abstract: Ultrafine phase change fibers based on polyethylene glycol (PEG)/cellulose acetate (CA) blends in which PEG acts as a model phase change material (PCM) and CA acts as a supporting material, were successfully prepared via electrospinning. The effect of PEG content on the morphology, crystalline properties, phase change behaviors and tensile properties of the composite fibers was studied systematically by field-emission scanning electron microscopy (FE-SEM), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and a tensile tester, respectively. The SEM observation indicates that maximum PEG content in the fibers could reach up to 70 wt%, and the morphology and average diameter of the composite fibers vary with PEG content. Thermal analysis results show that the latent heats of the phase change fibers increase with the increasing of PEG content in the fibers, and the PEG/CA fibers with high enthalpies have a good capability to regulate their interior temperature as the ambient temperature alters. Therefore, the developed phase change fibers have enormous applicable potentials in thermal energy storage and temperature regulation.

Recycling acetic acid from polarizing film of waste liquid crystal display panels by sub/supercritical water treatments.

Science.gov (United States)

Wang, Ruixue; Chen, Ya; Xu, Zhenming

2015-05-19

Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate) and organic materials (polarizing film and liquid crystal). The organic materials should be removed first since containing polarizing film and liquid crystal is to the disadvantage of the indium recycling process. In the present study, an efficient and environmentally friendly process to obtain acetic acid from waste LCD panels by sub/supercritical water treatments is investigated. Furthermore, a well-founded reaction mechanism is proposed. Several highlights of this study are summarized as follows: (i) 99.77% of organic matters are removed, which means the present technology is quite efficient to recycle the organic matters; (ii) a yield of 78.23% acetic acid, a quite important fossil energy based chemical product is obtained, which can reduce the consumption of fossil energy for producing acetic acid; (iii) supercritical water acts as an ideal solvent, a requisite reactant as well as an efficient acid-base catalyst, and this is quite significant in accordance with the "Principles of Green Chemistry". In a word, the organic matters of waste LCD panels are recycled without environmental pollution. Meanwhile, this study provides new opportunities for alternating fossil-based chemical products for sustainable development, converting "waste" into "fossil-based chemicals".

Acetate Kinase Isozymes Confer Robustness in Acetate Metabolism

DEFF Research Database (Denmark)

Chan, Siu Hung Joshua; Nørregaard, Lasse; Solem, Christian

2014-01-01

transcription structure, determining enzyme characteristics and effect on growth physiology. The results show that the two ACKs are most likely individually transcribed. AckA1 has a much higher turnover number and AckA2 has a much higher affinity for acetate in vitro. Consistently, growth experiments of mutant...... physiological roles in L. lactis to maintain a robust acetate metabolism for fast growth at different extracellular acetate concentrations. The existence of ACK isozymes may reflect a common evolutionary strategy in bacteria in an environment with varying concentrations of acetate.......Acetate kinase (ACK) (EC no: 2.7.2.1) interconverts acetyl-phosphate and acetate to either catabolize or synthesize acetyl-CoA dependent on the metabolic requirement. Among all ACK entries available in UniProt, we found that around 45% are multiple ACKs in some organisms including more than 300...

The use of sodium alginate-based coating and cellulose acetate in papaya post-harvest preservation

Directory of Open Access Journals (Sweden)

Denise Andrade Silva

2014-02-01

Full Text Available This study aimed to evaluate the ripening of papaya fruit (Carica papaya L. at room temperature (±25°C and10°C with 80% relative humidity, coated with edible film based on sodium alginate (1% and cellulose acetate film (3% by dipping the fruit in the suspensions for 1 min. On the application of the treatment and every three days during 12 days of storage, fruit were evaluated for weight loss, firmness, total carotenoid content, lycopene content and vitamin C content of the pulp. The cellulose acetate film extended the shelf-life of papayas, without affecting their quality. This treatment delayed fruit ripening, whose changes in all the parameters analyzed were significantly slower than fruit treated with sodium alginate-based coating. The coating with cellulose acetate at 3% was more effective in the preservation of papaya stored for 12 days under both temperatures.

Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery

Directory of Open Access Journals (Sweden)

Lyndon Jones

2012-01-01

Full Text Available Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials.

Silane Modification of Cellulose Acetate Dense Films as Materials for Acid Gas Removal

KAUST Repository

Achoundong, Carine S. K.; Bhuwania, Nitesh; Burgess, Steven K.; Karvan, Oguz; Johnson, Justin R.; Koros, William J.

2013-01-01

The modification of cellulose acetate (CA) films via grafting of vinyltrimethoxysilane (VTMS) to -OH groups, with subsequent condensation of hydrolyzed methoxy groups on the silane to form a polymer network is presented. The technique is referred to as GCV-modification. The modified material maintains similar H2S/CH4 and CO2/CH 4 selectivities compared to the unmodified material; however the pure CO2 and H2S permeabilities are 139 and 165 barrers, respectively, which are more than an order of magnitude higher than the neat polymer. The membranes were tested at feed pressures of up to 700 psia in a ternary 20 vol. %H2S/20 vol. % CO2/60 vol. % CH 4 mixture. Even under aggressive feed conditions, GCV-modified CA showed comparable selectivities and significantly higher permeabilities. Furthermore, GCV-modified membrane had a lower Tg, lower crystallinity, and higher flexibility than neat CA. The higher flexibility is due to the vinyl substituent provided by VTMS, thereby reducing brittleness, which could be helpful in an asymmetric membrane structure. © 2013 American Chemical Society.

Silane Modification of Cellulose Acetate Dense Films as Materials for Acid Gas Removal

KAUST Repository

Achoundong, Carine S. K.

2013-07-23

The modification of cellulose acetate (CA) films via grafting of vinyltrimethoxysilane (VTMS) to -OH groups, with subsequent condensation of hydrolyzed methoxy groups on the silane to form a polymer network is presented. The technique is referred to as GCV-modification. The modified material maintains similar H2S/CH4 and CO2/CH 4 selectivities compared to the unmodified material; however the pure CO2 and H2S permeabilities are 139 and 165 barrers, respectively, which are more than an order of magnitude higher than the neat polymer. The membranes were tested at feed pressures of up to 700 psia in a ternary 20 vol. %H2S/20 vol. % CO2/60 vol. % CH 4 mixture. Even under aggressive feed conditions, GCV-modified CA showed comparable selectivities and significantly higher permeabilities. Furthermore, GCV-modified membrane had a lower Tg, lower crystallinity, and higher flexibility than neat CA. The higher flexibility is due to the vinyl substituent provided by VTMS, thereby reducing brittleness, which could be helpful in an asymmetric membrane structure. © 2013 American Chemical Society.

Development of seasonal heat storage based on stable supercooling of a sodium acetate water mixture

DEFF Research Database (Denmark)

Furbo, Simon; Fan, Jianhua; Andersen, Elsa

2012-01-01

A number of heat storage modules for seasonal heat storages based on stable supercooling of a sodium acetate water mixture have been tested by means of experiments in a heat storage test facility. The modules had different volumes and designs. Further, different methods were used to transfer heat...... to and from the sodium acetate water mixture in the modules. By means of the experiments: • The heat exchange capacity rates to and from the sodium acetate water mixture in the heat storage modules were determined for different volume flow rates. • The heat content of the heat storage modules were determined....... • The reliability of the supercooling was elucidated for the heat storage modules for different operation conditions. • The reliability of a cooling method used to start solidification of the supercooled sodium acetate water mixture was elucidated. The method is making use of boiling CO2 in a small tank in good...

Acetic acid removal from corn stover hydrolysate using ethyl acetate and the impact on Saccharomyces cerevisiae bioethanol fermentation.

Science.gov (United States)

Aghazadeh, Mahdieh; Ladisch, Michael R; Engelberth, Abigail S

2016-07-08

Acetic acid is introduced into cellulose conversion processes as a consequence of composition of lignocellulose feedstocks, causing significant inhibition of adapted, genetically modified and wild-type S. cerevisiae in bioethanol fermentation. While adaptation or modification of yeast may reduce inhibition, the most effective approach is to remove the acetic acid prior to fermentation. This work addresses liquid-liquid extraction of acetic acid from biomass hydrolysate through a pathway that mitigates acetic acid inhibition while avoiding the negative effects of the extractant, which itself may exhibit inhibition. Candidate solvents were selected using simulation results from Aspen Plus™, based on their ability to extract acetic acid which was confirmed by experimentation. All solvents showed varying degrees of toxicity toward yeast, but the relative volatility of ethyl acetate enabled its use as simple vacuum evaporation could reduce small concentrations of aqueous ethyl acetate to minimally inhibitory levels. The toxicity threshold of ethyl acetate, in the presence of acetic acid, was found to be 10 g L(-1) . The fermentation was enhanced by extracting 90% of the acetic acid using ethyl acetate, followed by vacuum evaporation to remove 88% removal of residual ethyl acetate along with 10% of the broth. NRRL Y-1546 yeast was used to demonstrate a 13% increase in concentration, 14% in ethanol specific production rate, and 11% ethanol yield. This study demonstrated that extraction of acetic acid with ethyl acetate followed by evaporative removal of ethyl acetate from the raffinate phase has potential to significantly enhance ethanol fermentation in a corn stover bioethanol facility. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:929-937, 2016. © 2016 American Institute of Chemical Engineers.

Development of ethylene direct oxidation process acetic acid new manufacturing method; Echiren jikisanho sakusan shinseizoho no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

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

1999-03-05

Though existing acetic acid manufacturing which made the ethylene to be the starting material was two steps oxidation method of the via acetaldehyde, this study persons developed the new manufacturing method by the ethylenic direct oxyacid. In system of reaction, the following were realized by the development of palladium/heteropolyacid system composite catalyst: High activity and selectivity. In the purification system, the process of becoming, when the water consequentially forms azeotrope for the separation between acetic acid and extracting agent that extracting agent of alkyl acetate was done, that it was used and extracted, was developed. In the equipment material aspect, it is sufficient as a 316 stainless steel unlike other acetic acid manufacturing method. As an equipment scale, it has made to be the optium size for 5-200 thousand t/year, and that the location that it is more small-scale than methanol, carbonylation method and approaches the consumption ground is possible are features. The industrial plant for 100 thousand t/year based on this study carries out business operation in Oita since November, 1997. (translated by NEDO)

FTIR studies of chitosan acetate based polymer electrolytes

International Nuclear Information System (INIS)

Osman, Z.; Arof, A.K.

2003-01-01

Chitosan is the product when partially deacetylated chitin dissolves in dilute acetic acid. As such, depending on the degree of deacetylation, the carbonyl, C=O-NHR band can be observed at ∼1670 cm -1 and the amine, NH 2 band at 1590 cm -1 . When lithium triflate is added to chitosan to form a film of chitosan acetate-salt complex, the bands assigned to chitosan in the complex and the spectrum as a whole shift to lower wavenumbers. The carbonyl band is observed to shift to as low as 1645 cm -1 and the amine band to as low as 1560 cm -1 . These indicate chitosan-salt interactions. Also present are the bands due to lithium triflate i.e. ∼761, 1033, 1182 and 1263 cm -1 . When chitosan and ethylene carbonate (EC) are dissolved in acetic acid to form a film of plasticized chitosan acetate, the bands in the infrared spectrum of the films do not show any significant shift indicating that EC does not interact with chitosan. EC-LiCF 3 SO 3 interactions are indicated by the shifting of the C-O bending band from 718 cm -1 in the spectrum of EC to 725 cm -1 in the EC-salt spectrum. The Li + -EC is also evident in the ring breathing region at 893 cm -1 in the pure EC spectrum. This band has shifted to 898 cm -1 in the EC-salt spectrum. C=O stretching in the doublet observed at 1774 and 1803 cm -1 in the spectrum of pure EC has shifted to 1777 and 1808 cm -1 in the EC-salt spectrum

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

International Nuclear Information System (INIS)

Stumpf, Aisha S.G.; Bergmann, Carlos P.; Vicenzi, Juliane; Fetter, Rebecca; Mundstock, Karina S.

2009-01-01

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

A 9-vinyladenine-based molecularly imprinted polymeric membrane for the efficient recognition of plant hormone 1H-indole-3-acetic acid

International Nuclear Information System (INIS)

Chen Changbao; Chen Yanjun; Zhou Jie; Wu Chunhui

2006-01-01

9-Vinyladenine was synthesized as a novel functional monomer for molecular imprinting techniques and its structure was established with elemental analysis and 1 H NMR spectroscopy. The binding mechanism between this functional monomer 9-vinyladenine and the plant hormone 1 H-indole-3-acetic acid in acetonitrile was studied with UV-vis spectrophotometry. Based on this study, using 1 H-indole-3-acetic acid as a template molecule, a specific 9-vinyladenine-based molecularly imprinted polymeric membrane was prepared. Then, the resultant polymeric membrane morphologies were visualized with scanning electron microscopy, and the membrane permselectivity for 1 H-indole-3-acetic acid, 1 H-indole-3-butyric acid and kinetin was tested with separate experiments and competitive diffusion experiments. These results showed that the imprinted polymeric membrane prepared with 9-vinyladenine exhibited higher transport selectivity for the template molecule 1 H-indole-3-acetic acid than 1 H-indole-3-butyric acid or kinetin. The membrane prepared with 9-vinyladenine also took on higher permselectivity for 1 H-indole-3-acetic acid in comparison with the imprinted membrane made with methacrylic acid. It is predicted that the 9-vinyladenine-based molecularly imprinted membrane may be applicable to the assay of 1 H-indole-3-acetic acid or for the preparation of a molecularly imprinted polymer sensor for the analysis of 1 H-indole-3-acetic acid in plant samples

Life cycle inventory of sodium acetate and expanded graphite: Short report

Energy Technology Data Exchange (ETDEWEB)

Jungbluth, N. [ESU-Services Ltd., Uster (Switzerland); Nguyen, B. [Haute Ecole d' Ingenierie et de Gestion du canton de Vaud, Laboratoire d' Energetique Solaire et de Physique du BATiment, HEIG-VD / LESBAT, Yverdon-les-Bains (Switzerland)

2008-07-01

This short report for the Laboratory for Solar Energy and Building Physics at the University of Applied Sciences in Yverdon, Switzerland, takes a look at work being done on the issue of solar energy storage. The use of sodium acetate as a phase-change material is reviewed and considered as being a good way of optimising solar heating systems. The goal of this study was to assess if the energy gain resulting from the use of sodium acetate is balanced out or not by its embodied energy. The study investigated sodium acetate with and without expanded graphite. The paper discusses the life cycle inventory analysis of the two materials and provides some aggregated key indicators for further analysis. In general the ecoinvent methodology has been followed in order to achieve full consistency with the background data used and to provide an assessment of the materials' impact on the environment.

Cyclic Acetalization of Furfural on Porous Aluminosilicate Acid Catalysts

Directory of Open Access Journals (Sweden)

Hartati Hartati

2016-12-01

Full Text Available Porous aluminosilicate materials included microporous and mesoporous ZSM-5, hierarchical aluminosilicates, and mesoporous aluminosilicate were tested for acetalization of furfural (furan-2-carbaldehyde with propylene glycol. The existing synthesis methods for aluminosilicate and ZSM-5 were modified to produce aluminosilicate material with hierarchical porous structure. Catalytic activity in acetalization of furfural by propylene glycol were conducted by refluxed of the mixture of furfural, propylene glycol and catalyst, using toluene as solvent and nitrobenzene as internal standard, at 106 °C for 4 h. The result showed that a combination of two structure directing agents, tetrapropylammonium hydroxide (TPAOH and cetyltrimethylammonium bromide (CTAB and modification of catalytic crystallization produced an active aluminosilicate framework that provides a wide access for a bulky reactants and strong acid sites to catalyze the reaction. The pore structure and the strength of the Brønsted acid sites were crucial for the high conversion of furfural to produce a cyclic acetal.

Preparation, thermal and flammability properties of a novel form-stable phase change materials based on high density polyethylene/poly(ethylene-co-vinyl acetate)/organophilic montmorillonite nanocomposites/paraffin compounds

International Nuclear Information System (INIS)

Cai Yibing; Song Lei; He Qingliang; Yang Dandan; Hu Yuan

2008-01-01

The paraffin is one of important thermal energy storage materials with many desirable characteristics (i.e., high heat of fusion, varied phase change temperature, negligible supercooling, self-nucleating, no phase segregation and cheap, etc.), but has low thermal stability and flammable. Hence, a novel form-stable phase change materials (PCM) based on high density polyethylene (HDPE)/poly(ethylene-co-vinyl acetate) (EVA)/organophilic montmorillonite (OMT) nanocomposites and paraffin are prepared by twin-screw extruder technique. The structures of the HDPE-EVA/OMT nanocomposites and the form-stable PCM are evidenced by the X-ray diffraction (XRD), transmission electronic microscopy (TEM) and scanning electronic microscope (SEM). The results of XRD and TEM show that the HDPE-EVA/OMT nanocomposites form the ordered intercalated nanomorphology. The form-stable PCM consists of the paraffin, which acts as a dispersed phase change material and the HDPE-EVA/OMT nanocomposites, which acts as the supporting material. The paraffin disperses in the three-dimensional net structure formed by HDPE-EVA/OMT nanocomposites. The thermal stability, latent heat and flammability properties are characterized by thermogravimetry analysis (TGA), dynamic Fourier-transform infrared (FTIR), differential scanning calorimeter (DSC) and cone calorimeter, respectively. The TGA and dynamic FTIR analyses indicate that the incorporation of suitable amount of OMT into the form-stable PCM increase the thermal stability. The DSC results show that the latent heat of the form-stable PCM has a certain degree decrease. The cone calorimeter shows that the heat release rate (HRR) has remarkably decreases with loading of OMT in the form-stable PCM, contributing to the improved flammability properties

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

Directory of Open Access Journals (Sweden)

B. A. Mandagarán

2006-03-01

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.

Acetic acid extraction from aqueous solutions using fatty acids

NARCIS (Netherlands)

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

2014-01-01

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

Corrosion Behavior of PEO Coatings Formed on AZ31 Alloy in Phosphate-Based Electrolytes with Calcium Acetate Additive

Science.gov (United States)

Ziyaei, E.; Atapour, M.; Edris, H.; Hakimizad, A.

2017-07-01

The PEO coating started on magnesium AZ31 using a unipolar DC power source. The coating was generated in the electrolyte based on Na3PO4·12H2O and KOH with calcium acetate as additive. The x-ray diffraction method showed some phases containing calcium and phosphate, which was created in the presence of additive. Also, the EDS tests of the sample's surfaces proved the existence of calcium on the surface. Based on the electrochemical tests results, the most corrosion resistance belongs to the sample with calcium acetate additive. In fact, the results of the EIS tests showed the coating with calcium acetate has the highest resistance but the lowest capacitance. However, this state belongs to the surface morphology, the lower porosity, and surface chemical composition.

γ radiolysis of cellulose acetate

International Nuclear Information System (INIS)

Ali, S.M.; Clay, P.G.

1979-01-01

The major degradative process in γ-irradiated cellulose acetate is chain scission. For the dry powder the G/sub s/ value (number of scissions per 100 eV of energy absorbed) was found to be 7.1. The water-swollen material was found to degrade at the higher rate of G/sub s/ = 9.45. Additions of ethanol and methanol to the water brought about reductions in G/sub s/, whereas dissolved nitrous oxide produced an increase in G/sub s/. The useful life of cellulose acetate reverse osmosis membranes exposed to γ radiation was estimated by observations of the water permeation rate during irradiation. Membrane breakdown occurred at 15 Mrad in pure water, but the dose to breakdown was extended to 83 Mrad in the presence of 4% methanol. 3 figures, 1 table

Inhibition of Ice Growth and Recrystallization by Zirconium Acetate and Zirconium Acetate Hydroxide

Science.gov (United States)

Mizrahy, Ortal; Bar-Dolev, Maya; Guy, Shlomit; Braslavsky, Ido

2013-01-01

The control over ice crystal growth, melting, and shaping is important in a variety of fields, including cell and food preservation and ice templating for the production of composite materials. Control over ice growth remains a challenge in industry, and the demand for new cryoprotectants is high. Naturally occurring cryoprotectants, such as antifreeze proteins (AFPs), present one solution for modulating ice crystal growth; however, the production of AFPs is expensive and inefficient. These obstacles can be overcome by identifying synthetic substitutes with similar AFP properties. Zirconium acetate (ZRA) was recently found to induce the formation of hexagonal cavities in materials prepared by ice templating. Here, we continue this line of study and examine the effects of ZRA and a related compound, zirconium acetate hydroxide (ZRAH), on ice growth, shaping, and recrystallization. We found that the growth rate of ice crystals was significantly reduced in the presence of ZRA and ZRAH, and that solutions containing these compounds display a small degree of thermal hysteresis, depending on the solution pH. The compounds were found to inhibit recrystallization in a manner similar to that observed in the presence of AFPs. The favorable properties of ZRA and ZRAH suggest tremendous potential utility in industrial applications. PMID:23555701

Apparent interfacial shear strength of short-flax-fiber/starch acetate composites

DEFF Research Database (Denmark)

Andersons, J.; Modniks, J.; Joffe, R.

2016-01-01

The paper deals with an indirect industry-friendly method for identification of the interfacial shear strength (IFSS) in a fully bio-based composite. The IFSS of flax fiber/starch acetate is evaluated by a modified Bowyer and Bader method based on an analysis of the stress-strain curve of a short......-fiber-reinforced composite in tension. A shear lag model is developed for the tensile stress-strain response of short-fiber-reinforced composites allowing for an elastic-perfectly plastic stress transfer. Composites with different fiber volume fractions and a variable content of plasticizer have been analyzed. The apparent...... IFSS of flax/starch acetate is within the range of 5.5-20.5 MPa, depending on composition of the material. The IFSS is found to be greater for composites with a higher fiber loading and to decrease with increasing content of plasticizer. The IFSS is equal or greater than the yield strength of the neat...

Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor.

Science.gov (United States)

Mounir, Majid; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe

2016-02-01

The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV01, respectively, was evaluated in this study. The simultaneous production of gluconic and acetic acids was also examined in this study. Biochemical and molecular identification based on a 16s rDNA sequence analysis confirmed that these strains can be classified as Acetobacter pasteurianus. To assess the ability of the isolated strains to grow and produce acetic acid and gluconic acid at high temperatures, a semi-continuous fermentation was performed in a 20-L bioreactor. The two strains abundantly grew at a high temperature (41°C). At the end of the fermentation, the AF01 and CV01 strains yielded acetic acid concentrations of 7.64% (w/v) and 10.08% (w/v), respectively. Interestingly, CV01 was able to simultaneously produce acetic and gluconic acids during acetic fermentation, whereas AF01 mainly produced acetic acid. In addition, CV01 was less sensitive to ethanol depletion during semi-continuous fermentation. Finally, the enzymatic study showed that the two strains exhibited high ADH and ALDH enzyme activity at 38°C compared with the mesophilic reference strain LMG 1632, which was significantly susceptible to thermal inactivation. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Experimental studies on seasonal heat storage based on stable supercooling of a sodium acetate water mixture

DEFF Research Database (Denmark)

Furbo, Simon; Dragsted, Janne; Fan, Jianhua

2011-01-01

to transfer heat to and from the module have been tested. Further, a solidification start method, based on a strong cooling of a small part of the salt water mixture in the module by boiling CO2 in a small brass tank in good thermal contact to the outer side of the module wall, has been tested. Tests......Laboratory tests of a 230 l seasonal heat storage module with a sodium acetate water mixture have been carried out. The aim of the tests is to elucidate how best to design a seasonal heat storage based on the salt water mixture, which supercools in a stable way. The module can be a part...... of a seasonal heat storage, that will be suitable for solar heating systems which can fully cover the yearly heat demand of Danish low energy buildings. The tested module has approximately the dimensions 2020 mm x 1285 mm x 80 mm. The module material is steel and the wall thickness is 2 mm. Different methods...

The behaviour of tungsten electrodes in a mixture of acetic acid and acetic anhydride

International Nuclear Information System (INIS)

Pastor, T.J.; Vajgand, V.H.

1976-01-01

Tungsten electrodes have advantageously been used for potentiometric end-point detection in perchloric acid titration of bases in a mixture of acetic acid and acetic anhydride. They have also given good results in biamperometric detection of the equivalence point in continuous coulometric titration of small quantities of bases and acids in the same solvent. Tungsten electrodes in the presence of quinhydrone behave like platinum electrodes, but in biamperometric end-point determination in the absence of quinhydrone it is better to remove the oxide layer from their surface. Some other factors affecting their behaviour have also been studied. Errors in determination do not exceed +-2% even in titration of very small quantities of substances. (author)

Aluminium, extractable from soil samples by the acid ammonium acetate soil-testing method

Directory of Open Access Journals (Sweden)

Osmo Mäkitie

1968-05-01

Full Text Available The extractant, 0.5 M acetic acid –0.5 M ammonium acetate at pH 4.65, which is used in soil-testing, extracts relatively high amounts of aluminium from acid soils. The mean values of acetate-extractable aluminium at pH 4.65, 1.75 meq Al/100 g of soil, and of exchangeable aluminium (M KCI extraction, 0.41 meq Al were obtained from a material of 30 samples of acid soils (Table 2. Several other acetic acid ammonium acetate extractants, from M acetic acid to M ammonium acetate solution were also used for studying the extractability of soil aluminium. The soil-testing extractant can be used for the estimation of the soluble amounts of aluminium in acid soils, however, further studies are needed for a better interpretation of the ammonium acetate extractable (at pH 4.65 aluminium in our soils.

Characterization of cellulose acetate obtained from sugarcane bagasse by 1H-NMR

International Nuclear Information System (INIS)

Cerqueira, Daniel A.; Rodrigues Filho, Guimes; Carvalho, Rui A.; Valente, Artur J.M.

2009-01-01

Cellulose from sugarcane bagasse was used for synthesizing cellulose acetate with different degrees of substitution, which were characterized by 1 H-NMR through the relationship between the peak areas of the hydrogen atoms present at the acetate groups (-(C=O)OCH 3 ) and the peaks of the hydrogen bonded to the carbon atoms of the glycosidic rings. Suppression was carried out in order to remove the peak of residual water in the materials and the peak related to impurities in cellulose triacetate. Degree of substitution values obtained through the resonance deconvolution were compared to those obtained by chemical determination through an acid-base titration. The determined degrees of substitution of the cellulose samples were 2.94 and 2.60. (author)

Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

Science.gov (United States)

Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

2011-01-01

A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

Guiding principle for crystalline Si photovoltaic modules with high tolerance to acetic acid

Science.gov (United States)

Masuda, Atsushi; Hara, Yukiko

2018-04-01

A guiding principle for highly reliable crystalline Si photovoltaic modules, especially those with high tolerance to acetic acid generated by hydrolysis reaction between water vapor and an ethylene-vinyl acetate (EVA) encapsulant, is proposed. Degradation behavior evaluated by the damp heat test strongly depends on Ag finger electrodes and also EVA encapsulants. The acetic acid concentration in EVA on the glass side directly determines the degradation behavior. The most important factor for high tolerance is the type of Ag finger electrode materials when using an EVA encapsulant. Photovoltaic modules using newly developed crystalline Si cells with improved Ag finger electrode materials keep their maximum power of 80% of the initial value even after the damp heat test at 85 °C and 85% relative humidity for 10000 h. The pattern of dark regions in electroluminescence images is also discussed on the basis of the dynamics of acetic acid in the modules.

In situ electron microscopy of Braille microsystems: photo-actuation of ethylene vinyl acetate/carbon nanotube composites

Science.gov (United States)

Czaniková, Klaudia; Krupa, Igor; Račko, Dušan; Šmatko, Vasilij; Campo, Eva M.; Pavlova, Ewa; Omastová, Mária

2015-02-01

The development of new types of tactile displays based on the actuation of composite materials can aid the visually impaired. Micro/nano systems based on ethylene vinyl acetate (EVA) polymeric matrices enriched with multiwalled carbon nanotubes (MWCNT) can produce ensembles capable of light-induced actuation. In this report, we investigate two types of commercial EVA copolymers matrices containing 28 and 50 wt% vinyl-acetate (VA). Non-covalent modification of carbon nanotubes was achieved through a compatibilization technique that appends the pyrenenyl and cholesteryl groups on the carbon nanotubes (CNTs) surface. EVA/MWCNT nanocomposites were prepared by casting from a solution. These composites were shaped into Braille elements using molds. The deformation of the Braille element (BE) under light-emitting diode (LED) illumination was observed for the first time by in situ scanning electron microscopy (SEM). The superior actuation performance promoted by the EVA/MWCNT nanocomposites indicates that these materials will be useful in the future as light-driven micro/nano system actuators.

In situ electron microscopy of Braille microsystems: photo-actuation of ethylene vinyl acetate/carbon nanotube composites

International Nuclear Information System (INIS)

Czaniková, Klaudia; Krupa, Igor; Račko, Dušan; Omastová, Mária; Šmatko, Vasilij; Campo, Eva M; Pavlova, Ewa

2015-01-01

The development of new types of tactile displays based on the actuation of composite materials can aid the visually impaired. Micro/nano systems based on ethylene vinyl acetate (EVA) polymeric matrices enriched with multiwalled carbon nanotubes (MWCNT) can produce ensembles capable of light-induced actuation. In this report, we investigate two types of commercial EVA copolymers matrices containing 28 and 50 wt% vinyl-acetate (VA). Non-covalent modification of carbon nanotubes was achieved through a compatibilization technique that appends the pyrenenyl and cholesteryl groups on the carbon nanotubes (CNTs) surface. EVA/MWCNT nanocomposites were prepared by casting from a solution. These composites were shaped into Braille elements using molds. The deformation of the Braille element (BE) under light-emitting diode (LED) illumination was observed for the first time by in situ scanning electron microscopy (SEM). The superior actuation performance promoted by the EVA/MWCNT nanocomposites indicates that these materials will be useful in the future as light-driven micro/nano system actuators. (paper)

Solidification behavior and thermal conductivity of bulk sodium acetate trihydrate composites with thickening agents and graphite

DEFF Research Database (Denmark)

Dannemand, Mark; Johansen, Jakob Berg; Furbo, Simon

2016-01-01

Sodium acetate trihydrate is a promising phase change material for long term storage of solar thermal energy if supercooling is actively utilized. Well performing thermal energy storages need to be able to charge and discharge energy at a high rate. The relatively low thermal conductivity....... Investigations of the solidification behavior, the formation of cavities and thermal conductivity of composites based on sodium acetate trihydrate crystalizing with or without supercooling are presented in this paper. The thermal conductivity was measured with an ISOMET hot disc surface measurement probe....... Samples that crystalized without supercooling tended to form solid crystals near the heat transfer surface and cavities away from the heat transfer surface. The measured thermal conductivity was up to 0.7 W/m K in solid sodium acetate trihydrate. Samples that crystalized from supercooled state formed...

Normal Uptake of 11C-Acetate in Pancreas, Liver, Spleen, and Suprarenal Gland in PET

Directory of Open Access Journals (Sweden)

Bogdan Malkowski

2017-01-01

Full Text Available Purpose. C11-Acetate is radiotracer being considered an alternative to 18F-fluorodeoxyglucose. Evaluation of C11-acetate biodistribution in human parenchymal organs is described. Methods and Materials. 60 consecutive patients referred to C11-acetate PET CT suspected of renal or prostate cancer relapse with negative results (no recurrent tumor were included in the study. Acquisition from the base of skull to upper thigh was made 20 min after i.v. injection of 720 MBq of C11-acetate. The distribution was evaluated by measuring the uptake in pancreas (uncinate process and body separately, liver, spleen, and left suprarenal gland. Clinical data of included patients showed no abnormalities in these organs. Results. Biodistributions of C11-acetate radiotracer were compared in different organs. Standardized uptake values of 11C-acetate were significantly higher in pancreatic parenchyma (SUV mean 6,4 than in liver (SUV mean 3,3, spleen (SUV mean 4,5, or suprarenal gland (SUV mean 2,7 tissues. No significant difference was found between pancreatic head (SUV mean 6,4 and body (SUV mean 5,9 uptake. In case of all aforementioned organs, there were no differences either between both sexes or between formerly diagnosed tumors (renal and prostate. Conclusions. Evaluation of C11-acetate uptake differences in parenchymal organs will allow establishing normal patterns of distribution. High pancreatic uptake may be used in quantitative assessment of organ function in diffuse nonneoplastic pathology.

Measurement of the isotope ratio of acetic acid in vinegar by HS-SPME-GC-TC/C-IRMS.

Science.gov (United States)

Hattori, Ryota; Yamada, Keita; Shibata, Hiroki; Hirano, Satoshi; Tajima, Osamu; Yoshida, Naohiro

2010-06-23

Acetic acid is the main ingredient of vinegar, and the worth of vinegar often depends on the fermentation of raw materials. In this study, we have developed a simple and rapid method for discriminating the fermentation of the raw materials of vinegar by measuring the hydrogen and carbon isotope ratio of acetic acid using head space solid-phase microextraction (HS-SPME) combined with gas chromatography-high temperature conversion or combustion-isotope ratio mass spectrometry (GC-TC/C-IRMS). The measurement of acetic acid in vinegar by this method was possible with repeatabilities (1sigma) of +/-5.0 per thousand for hydrogen and +/-0.4 per thousand for carbon, which are sufficient to discriminate the origin of acetic acid. The fermentation of raw materials of several vinegars was evaluated by this method.

The Effect of Cellulose Acetate Concentration from Coconut Nira on Ultrafiltration Membrane Characters

Science.gov (United States)

Vaulina, E.; Widyaningsih, S.; Kartika, D.; Romdoni, M. P.

2018-04-01

Cellulose acetate is one of material in produce ultrafiltration membrane. Many efforts have been done to produce cellulose acetate from natural product to replace commercial one. In this research, ultrafiltration membrane has been produced from coconut flower water (nira). Ultrafiltration membrane is widely used in separation processes. This research aims to determine the characteristics of ultrafiltration membrane at a various concentration of cellulose acetate. The ultrafiltration membrane is conducted by phase inversion method at various concentration of cellulose acetate. The cellulose acetate concentration was 20%, 23% and 25% (w/w) with formamide as additives. The results showed that the greater the concentration of cellulose acetate, the smaller the flux value. The highest flux was a membrane with 20% cellulose acetate concentration with water flux value 55.34 L/(m2. h). But the greater the concentration of cellulose acetate the greater the rejection. The highest rejection value was on a membrane with 25% cellulose acetate concentration of 82.82%. While from the tensile strength test and the pore size analysis, the greater the cellulose acetate concentration the greater the tensile strength and the smaller the pore size

Long term thermal energy storage with stable supercooled sodium acetate trihydrate

DEFF Research Database (Denmark)

Dannemand, Mark; Schultz, Jørgen M.; Johansen, Jakob Berg

2015-01-01

Utilizing stable supercooling of sodium acetate trihydrate makes it possible to store thermal energy partly loss free. This principle makes seasonal heat storage in compact systems possible. To keep high and stable energy content and cycling stability phase separation of the storage material must...... it expands and will cause a pressure built up in a closed chamber which might compromise stability of the supercooling. This can be avoided by having an air volume above the phase change material connected to an external pressure less expansion tank. Supercooled sodium acetate trihydrate at 20 °C stores up...

Triacetin-based acetate supplementation as a chemotherapeutic adjuvant therapy in glioma.

Science.gov (United States)

Tsen, Andrew R; Long, Patrick M; Driscoll, Heather E; Davies, Matthew T; Teasdale, Benjamin A; Penar, Paul L; Pendlebury, William W; Spees, Jeffrey L; Lawler, Sean E; Viapiano, Mariano S; Jaworski, Diane M

2014-03-15

Cancer is associated with epigenetic (i.e., histone hypoacetylation) and metabolic (i.e., aerobic glycolysis) alterations. Levels of N-acetyl-L-aspartate (NAA), the primary storage form of acetate in the brain, and aspartoacylase (ASPA), the enzyme responsible for NAA catalysis to generate acetate, are reduced in glioma; yet, few studies have investigated acetate as a potential therapeutic agent. This preclinical study sought to test the efficacy of the food additive Triacetin (glyceryl triacetate, GTA) as a novel therapy to increase acetate bioavailability in glioma cells. The growth-inhibitory effects of GTA, compared to the histone deacetylase inhibitor Vorinostat (SAHA), were assessed in established human glioma cell lines (HOG and Hs683 oligodendroglioma, U87 and U251 glioblastoma) and primary tumor-derived glioma stem-like cells (GSCs), relative to an oligodendrocyte progenitor line (Oli-Neu), normal astrocytes, and neural stem cells (NSCs) in vitro. GTA was also tested as a chemotherapeutic adjuvant with temozolomide (TMZ) in orthotopically grafted GSCs. GTA-induced cytostatic growth arrest in vitro comparable to Vorinostat, but, unlike Vorinostat, GTA did not alter astrocyte growth and promoted NSC expansion. GTA alone increased survival of mice engrafted with glioblastoma GSCs and potentiated TMZ to extend survival longer than TMZ alone. GTA was most effective on GSCs with a mesenchymal cell phenotype. Given that GTA has been chronically administered safely to infants with Canavan disease, a leukodystrophy due to ASPA mutation, GTA-mediated acetate supplementation may provide a novel, safe chemotherapeutic adjuvant to reduce the growth of glioma tumors, most notably the more rapidly proliferating, glycolytic and hypoacetylated mesenchymal glioma tumors. © 2013 UICC.

Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

Energy Technology Data Exchange (ETDEWEB)

Senna, Magdy M., E-mail: magdysenna@hotmail.com [Radiation Chemistry Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt); Mostafa, Abo El-Khair B. [Chemistry Department, College for Girls, Ain Shams University, Cairo (Egypt); Mahdy, Sanna R.; El-Naggar, Abdel Wahab M. [Radiation Chemistry Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

2016-11-01

Highlights: • Semi-interpenetrating (IPN) blend hydrogels were synthesized by EB irradiation. • The hydrogels were based on starch/cellulose acetate/carboxymethyl cellulose blends. • The gelation, swelling, thermal and mechanical properties of hydrogels were studied. • The thermal stability was studied by determining kinetic energy by different methods. - Abstract: Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

International Nuclear Information System (INIS)

Senna, Magdy M.; Mostafa, Abo El-Khair B.; Mahdy, Sanna R.; El-Naggar, Abdel Wahab M.

2016-01-01

Highlights: • Semi-interpenetrating (IPN) blend hydrogels were synthesized by EB irradiation. • The hydrogels were based on starch/cellulose acetate/carboxymethyl cellulose blends. • The gelation, swelling, thermal and mechanical properties of hydrogels were studied. • The thermal stability was studied by determining kinetic energy by different methods. - Abstract: Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

Drug-loaded Cellulose Acetate and Cellulose Acetate Butyrate Films ...

African Journals Online (AJOL)

The purpose of this research work was to evaluate the contribution of formulation variables on release properties of matrix type ocular films containing chloramphenicol as a model drug. This study investigated the use of cellulose acetate and cellulose acetate butyrate as film-forming agents in development of ocular films.

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

DEFF Research Database (Denmark)

Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

2009-01-01

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

Kinetic Modelling and Experimental Study of Small Esters: Methyl Acetate and Ethyl Acetate

KAUST Repository

Ahmed, Ahfaz; Mehl, Marco; Lokachari, Nitin; Nilsson, Elna J.K.; Konnov, Alexander A.; Wagnon, Scott W.; Pitz, William J.; Curran, Henry J.; Roberts, William L.; Sarathy, Mani

2017-01-01

A detailed chemical kinetic mechanism comprising methyl acetate and ethyl acetate has been developed based on the previous work by Westbrook et al. [1]. The newly developed kinetic mechanism has been updated with new reaction rates from recent theoretical studies. To validate this model, shock tube experiments measuring ignition delay time have been conducted at 15 & 30 bar and equivalence ratio 0.5, 1.0 and 2.0. Another set of experiments measuring laminar burning velocity was also performed on a heat flux burner at atmospheric pressure over wide range of equivalence ratios [~0.7-1.4]. The new mechanism shows significant improvement in prediction of experimental data over earlier model across the range of experiments.

Kinetic Modelling and Experimental Study of Small Esters: Methyl Acetate and Ethyl Acetate

KAUST Repository

Ahmed, Ahfaz

2017-12-14

A detailed chemical kinetic mechanism comprising methyl acetate and ethyl acetate has been developed based on the previous work by Westbrook et al. [1]. The newly developed kinetic mechanism has been updated with new reaction rates from recent theoretical studies. To validate this model, shock tube experiments measuring ignition delay time have been conducted at 15 & 30 bar and equivalence ratio 0.5, 1.0 and 2.0. Another set of experiments measuring laminar burning velocity was also performed on a heat flux burner at atmospheric pressure over wide range of equivalence ratios [~0.7-1.4]. The new mechanism shows significant improvement in prediction of experimental data over earlier model across the range of experiments.

Variability of Acid-Base Status in Acetate-Free Biofiltration 84% versus Bicarbonate Dialysis

Directory of Open Access Journals (Sweden)

Harzallah Kais

2008-01-01

Full Text Available The ultimate goal of hemodialysis (HD treatment is to achieve the highest level of efficacy in the presence of maximal clinical tolerance. With an aim to offer good hemodynamic stability, as observed during the acetate-free biofiltration 14% (AFB 14% to patients who are intolerant to bicarbonate dialysis (BD and with less cost, we have developed since June 1994, a new HD technique, namely AFB 84%. This study was carried out to analyze acid-base variations during the AFB 84% in comparison to BD in hemodynamically stable patients on regular HD. This was a prospective randomized crossover study carried out on 12 patients (6 males and 6 females for a total of 144 HD sessions (72 BD and 72 AFB 84%. Patients with decompensated cardiomyopathy, respiratory diseases or uncontrolled hypertension were not included in the trial. All the patients were treated with BD or AFB 84%; the latter is characterized by the absence of acetate in the dialysate and a complete correction of buffer balance by post-dilutional infusion of bicarbonate-based replacement solution. The comparison of pre-dialysis arterial acid-base and blood-gas parameters revealed no significant differences of pH, HCO 3 - and paCO 2 levels between the two techniques. Analysis of post-dialysis parameters showed that, among patients dialyzed with BD, there was over correction of metabolic acidosis with a tendency towards metabolic alkalosis. In contrast, in patients dialyzed with AFB 84%, we observed a significant improvement in pH and HCO 3 - levels but the increase in paCO2 level was not significant. A comparison of these parameters between the two techniques showed statistically significant difference in pH, HCO3 - and paCO2 levels, but not for paO2 level. AFB 84% can offer some important advantages with the complete absence of acetate from the substitution fluids, and permits a better correction of metabolic acidosis than BD, without causing alkalosis.

Poly(ethylene glycol)-grafted cyclic acetals based polymer networks with non-water-swellable, biodegradable and surface hydrophilic properties

Energy Technology Data Exchange (ETDEWEB)

Yin, Ruixue, E-mail: qdruinyan@hotmail.com [Complex and Intelligent Research Center, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai (China); Zhang, Nan; Wu, Wentao [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Wang, Kemin, E-mail: kemin-wang@hotmail.com [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China)

2016-05-01

Cyclic acetals based biomaterial without acidic products during hydrolytic degradation is a promising candidate for tissue engineering applications; however, low hydrophilicity is still one limitation for its biomedical application. In this work, we aim to achieve non-water-swellable cyclic acetal networks with improved hydrophilicity and surface wettability by copolymerization of cyclic acetal units based monomer, 5-ethyl-5-(hydroxymethyl)-β,β-dimethyl-1, 3-dioxane-2-ethanol diacrylate (EHD) and methoxy poly(ethylene glycol) monoacrylate (mPEGA) under UV irradiation, to avoid swelling of conventional hydrogels which could limit their applicability in particular of the mechanical properties and geometry integrity. Various EHD/mPEGA networks were fabricated with different concentrations of mPEGA from 0 to 30%, and the results showed photopolymerization behavior, mechanical property and thermal stability could not be significantly affected by addition of mPEGA, while the surface hydrophilicity was dramatically improved with the increase of mPEGA and could achieve a water contact angle of 37° with 30% mPEGA concentration. The obtained EHD/mPEGA network had comparative degradation rate to the PECA hydrogels reported previously, and MTT assay indicated it was biocompatible to L929 cells. - Highlights: • Cyclic acetals contained EHD/mPEGA networks were fabricated by photopolymerization. • It can be degraded under simulated physiological condition without acidic products. • Surface hydrophilicity was increased without swelling in water.

High purity neodymium acetate from mixed rare earth carbonates

International Nuclear Information System (INIS)

Queiroz, Carlos A. da Silva; Rocha, Soraya M. Rizzo da; Vasconcellos, Mari E. de; Lobo, Raquel M.; Seneda, Jose A.; Pedreira, Walter dos R.

2011-01-01

A simple and economical chemical process for obtaining high purity neodymium acetate is discussed. The raw material in the form rare earth carbonate is produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography technique with a strong cationic resin, proper to water treatment, and without the use of retention ions was used for the fractionating of the rare earth elements (REE). In this way, it was possible to obtain 99.9% pure Nd 2 O 3 in yields greater than or equal 80%, with the elution of the REE using ammonium salt of ethylenediaminetetraacetic acid (EDTA) solution in pH controlled. The complex of EDTA-neodymium was transformed into neodymium oxide, which was subsequently dissolved in acetic acid to obtain the neodymium acetates. Molecular absorption spectrophotometry was used to monitor the neodymium content during the process and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the neodymium acetates. The typical neodymium acetates obtained contain the followings contaminants in μg g -1 : Sc(5.1); Y (0.9); La (1.0); Ce (6.1); Pr (34,4); Sm (12.8); Eu (1.1); Gd (15.4); Tb (29.3); Dy (5.2), Ho(7.4); Er (14.6); Tm (0.3); Yb (2.5); Lu (1.0). The high purity neodymium acetates obtained from this procedure have been applied, replacing the imported product, in research and development area on rare earth catalysts. (author)

Photodissociation spectroscopy of the Mg+-acetic acid complex

Science.gov (United States)

Abate, Yohannes; Kleiber, P. D.

2006-11-01

We have studied the structure and photodissociation of Mg+-acetic acid clusters. Ab initio calculations suggest four relatively strongly bound ground state isomers for the [MgC2H4O2]+ complex. These isomers include the cis and trans forms of the Mg+-acetic acid association complex with Mg+ bonded to the carbonyl O atom of acetic acid, the Mg+-acetic acid association complex with Mg+ bonded to the hydroxyl O atom of acetic acid, or to a Mg+-ethenediol association complex. Photodissociation through the Mg+-based 3p←3s absorption bands in the near UV leads to direct (nonreactive) and reactive dissociation products: Mg+, MgOH+, Mg(H2O )+, CH3CO+, and MgCH3+. At low energies the dominant reactive quenching pathway is through dehydration to Mg(H2O)+, but additional reaction channels involving C-H and C-C bond activation are also open at higher energies.

A case of anaphylactoid reaction to acetate in acetate-containing bicarbonate dialysate.

Science.gov (United States)

Misaki, Taro; Suzuki, Yumiko; Naito, Yoshitaka; Shiooka, Tempei; Isozaki, Taisuke

2015-05-01

A 35-year-old man with end-stage kidney disease due to chronic glomerulonephritis was admitted to our hospital to start maintenance hemodialysis (HD). One hour after starting the first session of HD, he experienced general pruritus, urticaria, and dyspnea. Signs and symptoms were resolved by discontinuing HD and administrating an antihistamine drug; HD-associated anaphylactoid reactions were therefore suspected. Over the next few HD sessions, we changed the dialysis membrane, anticoagulant, HD circuit and needle, in that order, but general pruritus and urticaria again appeared within 3 h after starting each session of HD. Finally, when we changed the dialysate from acetate-containing bicarbonate dialysate to acetate-free bicarbonate dialysate, urticaria was clearly less than that seen in previous HD sessions, and subsided after discontinuation of HD. Subsequently, 20 mg of oral prednisolone (PSL) was administered 1 h before starting HD, and the patient did not experience general pruritus, urticaria, or dyspnea after starting the session. When administered acetate-containing bicarbonate dialysate after oral PSL pretreatment, the patient again experienced general pruritus, urticaria and dyspnea. Few reports have been published on the occurrence of anaphylactoid reactions during HD using acetate dialysate. We report a rare case of anaphylactoid reactions with acetate in acetate-containing bicarbonate dialysate that were reduced with the use of acetate-free bicarbonate dialysate and oral PSL pretreatment.

Electrodes Modification Based on Metal-Free Phthalocyanine: Example of Electrochemical Sensors for the Detection of Acetic Acid

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Amadou L. Ndiaye

2015-01-01

Full Text Available Electroanalytical properties of tetra-tert-butyl phthalocyanine (PcH2-tBu modified electrodes are studied by cyclic voltammetry (CV. The modified electrodes are obtained by CV deposition techniques on gold (Au and glassy carbon (C screen-printed electrodes (SPEs and used for the electrochemical detection of acetic acid (AA. Based on the CV experiments, the electrodeposition mechanism is detailed. The modified PcH2-tBu electrodes reveal one oxidation and one reduction peak within the potential window of the working electrodes. In the presence of the analyte (acetic acid, the modified electrodes show sensitivity in the range of 10 mM to 400 mM. For the PcH2-tBu modified Au electrode, a limit of detection (LOD of 5.89 mM (based on the +0.06 V peak was obtained while for the PcH2-tBu modified C electrode a LOD of 17.76 mM (based on the +0.07 V peak was achieved. A signal decay of 17%, based on 20 experiments, is obtained when gold is used as working electrode. If carbon is used as working electrode a value of 7% is attained. A signal decay is observed after more than 50 cycles of experiments and is more pronounced when higher concentrations of acetic acid are used. A mechanism of sensing is proposed at the end.

Ethylene vinyl acetate (EVA) as a new drug carrier for 3D printed medical drug delivery devices

DEFF Research Database (Denmark)

Genina, Natalja; Hollander, Jenny; Jukarainen, Harri

2016-01-01

The main purpose of this work was to investigate the printability of different grades of ethylene vinyl acetate (EVA) copolymers as new feedstock material for fused-deposition modeling (FDM™)-based 3D printing technology in fabrication of custom-made T-shaped intrauterine systems (IUS......) and subcutaneous rods (SR). The goal was to select an EVA grade with optimal properties, namely vinyl acetate content, melting index, flexural modulus, for 3D printing of implantable prototypes with the drug incorporated within the entire matrix of the medical devices. Indomethacin was used as a model drug...... affected the drug release profiles from the filaments and printed prototype products: faster release from the prototypes over 30 days in the in vitro tests. To conclude, this study indicates that certain grades of EVA were applicable feedstock material for 3D printing to produce drug-loaded implantable...

Metabolic pathway engineering based on metabolomics confers acetic and formic acid tolerance to a recombinant xylose-fermenting strain of Saccharomyces cerevisiae

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Ishii Jun

2011-01-01

Full Text Available Abstract Background The development of novel yeast strains with increased tolerance toward inhibitors in lignocellulosic hydrolysates is highly desirable for the production of bio-ethanol. Weak organic acids such as acetic and formic acids are necessarily released during the pretreatment (i.e. solubilization and hydrolysis of lignocelluloses, which negatively affect microbial growth and ethanol production. However, since the mode of toxicity is complicated, genetic engineering strategies addressing yeast tolerance to weak organic acids have been rare. Thus, enhanced basic research is expected to identify target genes for improved weak acid tolerance. Results In this study, the effect of acetic acid on xylose fermentation was analyzed by examining metabolite profiles in a recombinant xylose-fermenting strain of Saccharomyces cerevisiae. Metabolome analysis revealed that metabolites involved in the non-oxidative pentose phosphate pathway (PPP [e.g. sedoheptulose-7-phosphate, ribulose-5-phosphate, ribose-5-phosphate and erythrose-4-phosphate] were significantly accumulated by the addition of acetate, indicating the possibility that acetic acid slows down the flux of the pathway. Accordingly, a gene encoding a PPP-related enzyme, transaldolase or transketolase, was overexpressed in the xylose-fermenting yeast, which successfully conferred increased ethanol productivity in the presence of acetic and formic acid. Conclusions Our metabolomic approach revealed one of the molecular events underlying the response to acetic acid and focuses attention on the non-oxidative PPP as a target for metabolic engineering. An important challenge for metabolic engineering is identification of gene targets that have material importance. This study has demonstrated that metabolomics is a powerful tool to develop rational strategies to confer tolerance to stress through genetic engineering.

Development of sodium acetate trihydrate-ethylene glycol composite phase change materials with enhanced thermophysical properties for thermal comfort and therapeutic applications.

Science.gov (United States)

Kumar, Rohitash; Vyas, Sumita; Kumar, Ravindra; Dixit, Ambesh

2017-07-12

The heat packs using phase change materials (PCMs) are designed for possible applications such as body comfort and medical applications under adverse situations. The development and performance of such heat packs rely on thermophysical properties of PCMs such as latent heat, suitable heat releasing temperature, degree of supercooling, effective heat releasing time, crystallite size, stability against spontaneous nucleation in metastable supercooled liquid state and thermal stability during heating and cooling cycles. Such PCMs are rare and the available PCMs do not exhibit such properties simultaneously to meet the desired requirements. The present work reports a facile approach for the design and development of ethylene glycol (EG) and aqueous sodium acetate trihydrate (SAT) based composite phase change materials, showing these properties simultaneously. The addition of 2-3 wt% EG in aqueous SAT enhances the softness of SAT crystallites, its degree of supercooling and most importantly the effective heat releasing time by ~10% with respect to aqueous SAT material. In addition, the maximum heat releasing temperature of aqueous SAT has been tailored from 56.5 °C to 55 °C, 54.9 °C, 53.5 °C, 51.8 °C and 43.2 °C using 2%, 3%, 5%, 7% and 10 wt% EG respectively, making the aqueous SAT-EG composite PCMs suitable for desired thermal applications.

Controlled Morphology and Mechanical Characterisation of Electrospun Cellulose Acetate Fibre Webs

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B. Ghorani

2013-01-01

Full Text Available The purpose was to interpret the varying morphology of electrospun cellulose acetate (CA fibres produced from single and binary solvent systems based on solubility parameters to identify processing conditions for the production of defect-free CA fibrous webs by electrospinning. The Hildebrand solubility parameter ( and the radius of the sphere in the Hansen space ( of acetone, acetic acid, water, N,N-dimethylacetamide (DMAc, methanol, and chloroform were examined and discussed for the electrospinning of CA. The Hildebrand solubility parameter ( of acetone and DMAc were found to be within an appropriate range for the dissolution of CA. The suitability of the binary solvent system of acetone: DMAc (2 : 1 for the continuous electrospinning of defect-free CA fibres was confirmed. Electrospun webs exhibited improved tensile strength and modulus after heat and alkali treatment (deacetylation of the as-spun material, and no major fibre morphological degradation occurred during the deacetylation process.

Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

Science.gov (United States)

Wang, Bin; Shao, Yanchun; Chen, Fusheng

2015-02-01

Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided.

Biosynthetic origin of acetic acid using SNIF-NMR

International Nuclear Information System (INIS)

Boffo, Elisangela Fabiana; Ferreira, Antonio Gilberto

2006-01-01

The main purpose of this work is to describe the use of the technique Site-Specific Natural Isotopic Fractionation of hydrogen (SNIF-NMR), using 2 H and 1 H 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 C 3 , C 4 , and CAM biosynthetic mechanisms, blends of C 3 and C 4 (agrins) and synthetic acetic acid. (author)

Antioxidant Microemulsion-based Ethylene Vinyl Acetate Film Containing Mangiferin and Surfactants

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Boonnattakorn Rungkan

2016-01-01

Full Text Available Mangiferin, a natural antioxidant additive, was incorporated into an ethylene vinyl acetate copolymer (EVA containing 18% vinyl acetate (VA using the emulsion solvent evaporation technique. Sorbitan ester (Span®20 and polymeric surfactant (Pluronic®P−123 were compared. Mangiferin was finely dispersed in the suspension with the addition of surfactants studied. Span®20 was chosen as the surfactant for film preparation in the next step due to the dispersing and film forming properties. Effects of vinyl acetate (VA contents on the film properties were investigated. The EVA films with 12% VA had the highest tensile strength and oxygen barrier, followed by 18, 25 and 40% VA, respectively. Addition of Span®20 had only a slight effect on mechanical and barrier properties of the films, but markedly increased the release of mangiferin from the EVA matrices except in the 40% VA films. The maximum concentrations of mangiferin released from the 40, 25, 18 and 12% VA films into 95% ethanol were 83.30, 66.84, 51.77 and 34.57 μg·mL−11, respectively. The release concentrations from the 40 and 25% VA films was 2.4 and 1.9 folds of that from the 12% VA film, respectively. The antioxidant activity of the EVA films containing mangiferin and Span®20 was 80% radical-scavenging capacity (RSC for the 40 and 25% VA and 60% RSC for the 18 and 12% VA. The release of mangiferin from the EVA matrices may be controlled by appropriate selection of the surfactants and vinyl acetate contents.

Protective effects of piperine on lead acetate induced-nephrotoxicity in rats

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Sri Agus Sudjarwo

2017-11-01

Full Text Available Objective(s: In this study, we investigated the protective effects of piperine on lead acetate-induced renal damage in rat kidney tissue. Materials and Methods: Forty male rats were divided into 5 groups: negative control (rats were given aquadest daily, positive control (rats were given lead acetate 30 mg/kg BW orally once a day for 60 days, and the treatment group (rats were given piperine 50 mg; 100 mg and 200 mg/kg BW orally once a day for 65 days, and on 5th day, were given lead acetate 30 mg/kg BW one hr after piperine administration for 60 days. On day 65 levels of blood urea nitrogen (BUN, creatinine, malondialdehyde (MDA, Superoxide Dismutase (SOD, and Glutathione Peroxidase (GPx were measured. Also, kidney samples were collected for histopathological studies. Results: The results revealed that lead acetate toxicity induced a significant increase in the levels of BUN, creatinine, and MDA; moreover, a significant decrease in SOD and GPx. Lead acetate also altered kidney histopathology (kidney damage, necrosis of tubules compared to the negative control. However, administration of piperine significantly improved the kidney histopathology, decreased the levels of BUN, creatinine, and MDA, and also significantly increased the SOD and GPx in the kidney of lead acetate-treated rats. Conclusion: From the results of this study it was concluded that piperine could be a potent natural herbal product exhibiting nephroprotective effect against lead acetate induced nephrotoxicity in rats.

Cellulose acetate-based molecularly imprinted polymeric membrane for separation of vanillin and o-vanillin

OpenAIRE

Zhang,Chunjing; Zhong,Shian; Yang,Zhengpeng

2008-01-01

Cellulose acetate-based molecularly imprinted polymeric membranes were prepared using vanillin as template molecule. The microscopic structure of the resultant polymeric membranes was characterized by SEM and FTIR spectroscopy, and the selective binding properties and separation capacity of the membranes for vanillin and o-vanillin were tested with binding experiments and separate experiments, respectively. The results showed that the vanillin-imprinted polymeric membranes displayed higher bi...

Preparation of neodymium acetate for use in nuclear area and nanotechnology

Energy Technology Data Exchange (ETDEWEB)

Queiroz, C.A.S.; Seneda, J.A., E-mail: cqueiroz@ipen.br, E-mail: jaseneda@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Filho, W. R. Pedreira, E-mail: walter.pedreira@fundacentro.gov.br [Fundação Jorge Duprat Figueiredo, de Segurança e Medicina do Trabalho (FUNDACENTRO), Sao Paulo, SP (Brazil)

2017-07-01

Neodymium and its compounds are being increasingly applied in the manufacture of new materials. In nuclear area neodymium isotopes are used in a variety of scientific applications. Nd-142 has been used to produce short-lived Tm and Yb isotopes. Nd-146 has been suggested to produce Pm-147 and Nd-150 has been used to study double beta decay. Due to the several modern applications using nanomaterials, more and more highly rare earth compounds have been demanded. The researches at IPEN uses the experience gained in rare earth separation for the preparation of some pure acetates, purity > 99.9% for application in nanotechnology research. A simple and economical chemical process to obtaining neodymium acetate of high purity is studied. The raw material in the form of mixed rare earths carbonate comes from Brazilian monazite. It is used the technique of strong cationic exchange resin, proper to water treatment, to the neodymium's fractionation and it is achieved a purity of 99.9% in Nd{sub 2}O{sub 3} and yield greater than or equal 80%, with the elution of rare earths by EDTA solution in pH controlled. The complex of EDTA-neodymium is transformed in neodymium oxide, subsequently the oxide is dissolved in acetic acid to obtain the neodymium acetate. The solid salt was characterized via molecular absorption spectrophotometry, mass spectrometry, thermal analysis, chemical analysis and X ray diffraction. In summary the analytical data collected allowed to conclude that the stoichiometric formula for the neodymium acetate prepared is Nd(CH {sub 3}COOH)3.1.5H{sub 2}O. (author)

21 CFR 184.1185 - Calcium acetate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium acetate. 184.1185 Section 184.1185 Food and... Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be...

The Cholesterol-Lowering Effect of Alisol Acetates Based on HMG-CoA Reductase and Its Molecular Mechanism

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Fei Xu

2016-01-01

Full Text Available This study measured the impact of alisol B 23-acetate and alisol A 24-acetate, the main active ingredients of the traditional Chinese medicine Alismatis rhizoma, on total cholesterol (TC, triglyceride (TG, high density lipoprotein-cholesterol (HDL-C, and low density lipoprotein-cholesterol (LDL-C levels of hyperlipidemic mice. The binding of alisol B 23-acetate and alisol A 24-acetate to the key enzyme involved in the metabolism of TC, 3-hydroxy-3-methylglutary-coenzyme A (HMG-CoA reductase, was studied using the reagent kit method and the western blotting technique combined with a molecular simulation technique. According to the results, alisol acetates significantly lower the TC, TG, and LDL-C concentrations of hyperlipidemic mice, while raising HDL-C concentrations. Alisol acetates lower HMG-CoA reductase activity in a dose-dependent fashion, both in vivo and in vitro. Neither of these alisol acetates significantly lower the protein expression of HMG-CoA. This suggests that alisol acetates lower the TC level via inhibiting the activity of HMG-CoA reductase by its prototype drug, which may exhibit an inhibition effect via directly and competitively binding to HMG-CoA. The side chain of the alisol acetate was the steering group via molecular simulation.

Acetic acid dressings: Finding the Holy Grail for infected wound management

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Kapil S Agrawal

2017-01-01

Full Text Available Background: Wounds have since long, contributed majorly to the health-care burden. Infected long-standing non-healing wounds place many demands on the treating surgeon and are devastating for the patients physically, nutritionally, vocationally, financially, psychologically and socially. Acetic acid has long been included among agents used in the treatment of infected wounds. In this study, we have evaluated the use of acetic acid for topical application in the treatment of infected wounds. Materials and Methods: A total of 100 patients with infected wounds were treated with topical application of 1% acetic acid as dressing material after appropriate cleaning. A specimen of wound swab was collected before first application and further on days 3, 7, 10 and 14. Daily dressings of wounds were done similarly. Minimum inhibitory concentration (MIC of acetic acid against various organisms isolated was determined. Results: The patients treated ranged between 9 and 60 years, with the mean age 33 years. Nearly 70% of patients were male. Aetiologies of wounds: infective 35, diabetic 25, trauma 20, burns 10, venous ulcers 5 and infected graft donor site 5. Various microorganisms isolated include Pseudomonas aeruginosa (40%, Staphylococcus aureus (2%, Acinetobacter (12%, Escherichia Coli (5%, Proteus mirabilis (3%, Klebsiella (18%, methicillin-resistant S. aureus (10%, Streptococcus (2% and Enterococcus (1%, Citrobacter (1%. Few wounds (6% also isolated fungi. About 28%, 64% and 8% of patients isolated no growth on culture after 7, 14 and 21 days, respectively. MIC of all isolated organisms was ≤0.5%. Conclusion: pH of the wound environment plays a pivotal role in wound healing. Acetic acid with concentration of 1% has shown to be efficacious against wide range of bacteria as well as fungi, simultaneously accelerating wound healing. Acetic acid is non-toxic, inexpensive, easily available and efficient topical agent for effective elimination of wound

Obtaining of inulin acetate

OpenAIRE

Khusenov, Arslonnazar; Rakhmanberdiev, Gappar; Rakhimov, Dilshod; Khalikov, Muzaffar

2014-01-01

In the article first obtained inulin ester inulin acetate, by etherification of inulin with acetic anhydride has been exposed. Obtained product has been studied using elementary analysis and IR spectroscopy.

Luminescence properties of uranyl-acetate species

Energy Technology Data Exchange (ETDEWEB)

Brinkmann, Hannes; Moll, Henry [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology; Stumpf, Thorsten [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry

2017-06-01

Time-resolved laser-induced fluorescence spectroscopy (TRLFS) was applied to characterize uranium(VI)- acetate species based on their luminescence properties. In contrast to previous interpretations, no indications were detected for the existence of the 1: 3 complex.

Acetate in Oz: Some Strategic Moves

Directory of Open Access Journals (Sweden)

Colin Webb

2005-08-01

Full Text Available I would like to add my voice to the words of congratulations and thanks to the British Library for organising this forum, and for their generosity in making it possible for me to come across the world to be part of it. The issues we are discussing today have an importance extending beyond cellulose acetate, as they reflect our ability as custodians to deal with common threats to the documentary heritage we are charged with preserving. As I will argue later, we need to see this situation in the context of the full range of preservation management issues that face our institutions. While it imposes a burden and a challenge on us as preservation managers, it also presents opportunities to sort out some things that have needed attention for some time. I have been asked to talk about problems with cellulose acetate microfilm collections in Australia, and specifically the strategies – both national and local – that have been adopted or at least explored in response to those problems. In the time I have I will not be going into any of these in great detail, but I hope I can give you some sense of the situation down under, and perhaps draw out a few issues that might make this more than just an ‘us too’ session! One thing to emphasise from the start is that we have had a number of goes at dealing with acetate microfilm collections: it is not a newly discovered problem in Australia. One significant context in which we have been working is that of a national strategy for all kinds of cellulose acetate collection materials. Explaining this national strategy will form a major part of my presentation, with issues and approaches specific to microfilm discussed towards the end.

Hydroxide as general base in the saponification of ethyl acetate.

Science.gov (United States)

Mata-Segreda, Julio F

2002-03-13

The second-order rate constant for the saponification of ethyl acetate at 30.0 degrees C in H(2)O/D(2)O mixtures of deuterium atom fraction n (a proton inventory experiment) obeys the relation k(2)(n) = 0.122 s(-1) M(-1) (1 - n + 1.2n) (1 - n + 0.48n)/(1 - n + 1.4n) (1 - n + 0.68n)(3). This result is interpreted as a process where formation of the tetrahedral intermediate is the rate-determining step and the transition-state complex is formed via nucleophilic interaction of a water molecule with general-base assistance from hydroxide ion, opposite to the direct nucleophilic collision commonly accepted. This mechanistic picture agrees with previous heavy-atom kinetic isotope effect data of Marlier on the alkaline hydrolysis of methyl formate.

Characterization of acetate-utilizing methanogenic bacteria, depending on varying acetate concentrations, in a biogas plant. Phase 1

International Nuclear Information System (INIS)

Ahring, B.K.

1994-12-01

The present report contains the results of a project concerning behaviour of acetate-utilizing methanogenic bacteria in mesophilic and thermophilic biogas plants, collected in 1992 - 1994 period. Labelled acetates (2-C 14 -CH 3 COOH) have been used to characterize the types of methane bacteria populations in the Danish biogas plants, the optimum acetate concentration for these bacteria and acetate metabolism in mesophilic and thermophilic biogas reactors with low acetate concentrations. 2 publications are included. (EG)

ACETIC ACID AND A BUFFER

DEFF Research Database (Denmark)

2009-01-01

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

Additive effects of acetic acid upon hydrothermal reaction of amylopectin

International Nuclear Information System (INIS)

Sugano, Motoyuki; Katoh, Harumi; Komatsu, Akihiro; Kobayashi, Hiroshi; Okado, Kohta; Kakuta, Yusuke; Hirano, Katsumi

2012-01-01

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

Ethanol-induced activation of adenine nucleotide turnover. Evidence for a role of acetate

International Nuclear Information System (INIS)

Puig, J.G.; Fox, I.H.

1984-01-01

Consumption of alcohol causes hyperuricemia by decreasing urate excretion and increasing its production. Our previous studies indicate that ethanol administration increases uric acid production by increasing ATP degradation to uric acid precursors. To test the hypothesis that ethanol-induced increased urate production results from acetate metabolism and enhanced adenosine triphosphate turnover, we gave intravenous sodium acetate, sodium chloride and ethanol (0.1 mmol/kg per min for 1 h) to five normal subjects. Acetate plasma levels increased from 0.04 +/- 0.01 mM (mean +/- SE) to peak values of 0.35 +/- 0.07 mM and to 0.08 +/- 0.01 mM during acetate and ethanol infusions, respectively. Urinary oxypurines increased to 223 +/- 13% and 316 +/- 44% of the base-line values during acetate and ethanol infusions, respectively. Urinary radioactivity from the adenine nucleotide pool labeled with [8-14C] adenine increased to 171 +/- 27% and to 128 +/- 8% of the base-line values after acetate and ethanol infusions. These data indicate that both ethanol and acetate increase purine nucleotide degradation by enhancing the turnover of the adenine nucleotide pool. They support the hypothesis that acetate metabolism contributes to the increased production of urate associated with ethanol intake

A randomized controlled study on the effects of acetate-free biofiltration on organic anions and acid-base balance in hemodialysis patients.

Science.gov (United States)

Sánchez-Canel, Juan J; Hernández-Jaras, Julio; Pons-Prades, Ramón

2015-02-01

Metabolic acidosis correction is achieved by the transfer of bicarbonate and other buffer anions in dialysis. The aim of this study was to evaluate changes in the main anions of intermediary metabolism on standard hemodiafiltration (HDF) and on acetate-free biofiltration (AFB). A prospective, in-center, crossover study was carried out with 22 patients on maintenance dialysis. Patients were randomly assigned to start with 12 successive sessions of standard HDF with bicarbonate (34 mmol/L) and acetate dialysate (3 mmol/L) or 12 successive sessions of AFB without base in the dialysate. Acetate increased significantly during the standard HDF session from 0.078 ± 0.062 mmol/L to 0.156 ± 0.128 mmol/L (P acid-base equilibrium through a bicarbonate substitution fluid. It also prevents hyperacetatemia and restores internal homeostasis with less production of intermediary metabolites. © 2014 The Authors. Therapeutic Apheresis and Dialysis © 2014 International Society for Apheresis.

Preparation of Thermoplastic Poly (vinyl Alcohol), Ethylene Vinyl Acetate and Vinyl Acetate Versatic Ester Blends for Exterior Masonry Coating

International Nuclear Information System (INIS)

EL-Nahas, H.H.; Gad, Y.H.; Magida, M.M.

2013-01-01

Blend systems including ethylene vinyl acetate (EVA), poly (vinyl alcohol) (PVA) and vinyl acetate versatic copolymer latex (VAcVe) were prepared and used as exterior coatings. Mechanical and thermal properties of the blends were investigated using a testo meter, shore hardness tester, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The water resistance of the samples was measured. Effect of ionizing irradiation on gel content, tensile strength and surface hardness were also followed. The blend offers binder base for exterior masonry coating systems having superior water resistant and mechanical properties

Chromium base high performance materials: Where and how do they come from?

Science.gov (United States)

Choi, In-Kap

1996-08-01

The origin of chromium base performance materials (CBPM) is described. CBPM may include (1) trivalent chromium chemicals such as chromic acetate, chromic chloride, chromic bromide, chromic fluoride, chromic iodide, chromic phosphate, and chromic sulfate; (2) hexavalent chromium chemicals such as chromic acid, lithium chromate, sodium chromate, sodium dichromate, and potassium dichromate; (3) oxide forms of chromium such as black chrome, chromium dioxide, chromium oxide, and chromium hydroxide; and (4) other chromium compounds such as chromium aluminide, chromium boride, chromium carbide, chromium molybdate, chromium nitride, chromium silicide, chromium tungstate and lanthanum chromite. Extensive reviews of production processes, properties, and applications/end uses of CBPM are made.

Tailor-made starch-based conjugates containing well-defined poly(vinyl acetate and its derivative poly(vinyl alcohol

Directory of Open Access Journals (Sweden)

2011-06-01

Full Text Available Reversible addition-fragmentation chain transfer (RAFT polymerization was adopted to synthesize starch-based conjugates that possessed controllable architecture and properties. Starch-based xanthate agent was prepared and applied as chain transfer agent to conduct the living/controlled polymerization (LCP of vinyl acetate, which generated tailor-made conjugates of starch and well-defined poly(vinyl acetate (SVAc. The relevant derivatives, conjugates of starch and chain length-controlled poly(vinyl alcohol (SVA, were obtained subsequently. Various characterizations such as Fourier transform infrared spectra (FTIR, ultraviolet-visible spectroscopy (UV, proton nuclear magnetic resonance (1H NMR, gel permeation chromatography (GPC, X-ray diffraction (XRD, Thermogravimetric analysis (TGA, and dynamic mechanical thermal analysis (DMTA were performed to examine the structure of intermediates and the starch-based conjugates. Static contact angle measurements revealed that the hydrophilic character of starch-based conjugates was tunable. Well-defined SVAc was amphiphilic and it was able to self-assemble into size controllable micelles, which was verified by contact angles, transmission electron microscopy (TEM and dynamic light scattering (DLS tests. SVA exhibited much higher capability to form physically cross-linked hydrogel than starch did. Both the characteristic of SVAc and SVA were chain length-dependent.

Resinas acetálicas: diversas aplicaciones en odontoestomatología

OpenAIRE

Puigpelat Martí, Ana M.; Casanellas Bassols, Josep M. (Josep Maria)

1994-01-01

La resina acetálica o Polioxime­tileno (POM) es un nuevo material estético de reciente aplicación en el campo de la Odontoestomatolo­gía. En este artículo presentamos al­gunas de las aplicaciones donde la estética desempeña una función importante. Una de las aplicaciones de las re­sinas acetálicas es el campo de la Prótesis Parcial Removible, cuan­do queremos sustituir los retene­dores vestibulares convencionales (metálicos) por retenedores más es­téticos. Otra posible aplicación puede ser la...

Experimental investigations on heat content of supercooled sodium acetate trihydrate by a simple heat loss method

DEFF Research Database (Denmark)

Kong, Weiqiang; Dannemand, Mark; Johansen, Jakob Berg

2016-01-01

Sodium acetate trihydrate is a phase change material that can be used for long term heat storage in solar heating systems because of its relatively high heat of fusion, a melting temperature of 58 °C and its ability to supercool stable. In practical applications sodium acetate trihydrate tend to ......, 0.3–0.5 % (wt.%) Xanthan Gum or 1–2% (wt.%) of some solid or liquid polymers as additives had significantly higher heat contents compared to samples of sodium acetate trihydrate suffering from phase separation....

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

Science.gov (United States)

Tanino, Takanori; Nara, Youhei; Tsujiguchi, Takuya; Ohshima, Takayuki

2013-08-01

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 μA/cm² and 2.47 μW/cm², respectively) were obtained after the second batch fermentation. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Synthesis of acetic acid via methanol hydrocarboxylation with CO2 and H2.

Science.gov (United States)

Qian, Qingli; Zhang, Jingjing; Cui, Meng; Han, Buxing

2016-05-11

Acetic acid is an important bulk chemical that is currently produced via methanol carbonylation using fossil based CO. Synthesis of acetic acid from the renewable and cheap CO2 is of great importance, but state of the art routes encounter difficulties, especially in reaction selectivity and activity. Here we report a route to produce acetic acid from CO2, methanol and H2. The reaction can be efficiently catalysed by Ru-Rh bimetallic catalyst using imidazole as the ligand and LiI as the promoter in 1,3-dimethyl-2-imidazolidinone (DMI) solvent. It is confirmed that methanol is hydrocarboxylated into acetic acid by CO2 and H2, which accounts for the outstanding reaction results. The reaction mechanism is proposed based on the control experiments. The strategy opens a new way for acetic acid production and CO2 transformation, and represents a significant progress in synthetic chemistry.

Effect of antimicrobial agents on cellulose acetate nano composites properties

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo, E-mail: francisco.rodriguez.m@usach.cl [Center for the Development of Nanoscience and Nanotechnology (CEDENNA). Universidad de Santiago de Chile. Faculty of Technology. Department of Food Science and Technology. Food Packaging Laboratory. Santiago (Chile)

2011-07-01

Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

Effect of antimicrobial agents on cellulose acetate nano composites properties

International Nuclear Information System (INIS)

Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo

2011-01-01

Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

Cellulose acetate membranes functionalized with resveratrol by covalent immobilization for improved osseointegration

Science.gov (United States)

Pandele, A. M.; Neacsu, P.; Cimpean, A.; Staras, A. I.; Miculescu, F.; Iordache, A.; Voicu, S. I.; Thakur, V. K.; Toader, O. D.

2018-04-01

Covalent immobilization of resveratrol onto cellulose acetate polymeric membranes used as coating on a Mg-1Ca-0.2Mn-0.6Zr alloy is presented for potential application in the improvement of osseointegration processes. For this purpose, cellulose acetate membrane is hydrolysed in the presence of potassium hydroxide, followed by covalent immobilization of aminopropyl triethoxy silane. Resveratrol was immobilized onto membranes using glutaraldehyde as linker. The newly synthesised functional membranes were thoroughly characterized for their structural characteristics determination employing X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FT-IR), Raman spectroscopy, thermogravimetric analysis (TGA/DTG) and scanning electron microscopy (SEM) techniques. Subsequently, in vitro cellular tests were performed for evaluating the cytotoxicity biocompatibility of synthesized materials and also the osseointegration potential of obtained derivatised membrane material. It was demonstrated that both polymeric membranes support viability and proliferation of the pre-osteoblastic MC3T3-E1 cells, thus providing a good protection against the potential harmful effects of the compounds released from coated alloys. Furthermore, cellulose acetate membrane functionalized with resveratrol exhibits a significant increase in alkaline phosphatase activity and extracellular matrix mineralization, suggesting its suitability to function as an implant surface coating for guided bone regeneration.

Synthesis, characterization and thermogravimetric study of zinc and cadmium acetates-polyaniline hybrids

International Nuclear Information System (INIS)

Fernandes de Farias, Robson

2004-01-01

By dissolution of respective acetates and conducting polymer in dimethylformamide, homogeneous zinc acetate and cadmium acetate-polyaniline (PANI) hybrids were synthesized and characterized by infrared spectroscopy, thermogravimetry and SEM microscopy. The infrared spectra suggests that there are interactions between PANI and the metal cations involving both, imine and amine nitrogens in a typical Lewis acid-base reaction. The thermogravimetric degradation profile of the synthesized hybrids resembles those exhibited by PANI samples

Optimisation of continuous gas fermentation by immobilisation of acetate-producing Acetobacterium woodii.

Science.gov (United States)

Steger, Franziska; Rachbauer, Lydia; Windhagauer, Matthias; Montgomery, Lucy F R; Bochmann, Günther

2017-08-01

Hydrogen from water electrolysis is often suggested as a way of storing the excess energy from wind and solar power plants. However, unlike natural gas, hydrogen is difficult to store and distribute. One solution is to convert the hydrogen into other fuels or bulk chemicals. In this study we investigated fermentation in which homoacetogenic clostridia apply the Wood-Ljungdahl pathway to generate acetate from H 2 and CO 2 . Acetate can be used as a bulk chemical or further transformed into biofuels. Autotrophic growth with CO 2 as the sole carbon source is slow compared to heterotrophic growth, so the aim of this work was to improve continuous gas fermentation by immobilising the acetate-producing clostridia, thus preventing their wash out from the bioreactor. Two homoacetogenic bacterial strains (Acetobacterium woodii and Moorella thermoacetica) were tested for their acetate production potential, with A. woodii proving to be the better strain with maximum acetate concentration of 29.57 g l -1 . Due to its stability during fermentation and good bacterial immobilisation, linen was chosen as immobilisation material for continuous fermentation. This study demonstrates the successful continuous fermentation of acetate from H 2 and CO 2 using A. woodii immobilised on a low-cost surface at high volumetric productivity of 1.21 ± 0.05 g acetate l -1 d -1 . This has great industrial potential and future studies should focus on the scale-up of this process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Acetate self-mixing and direct thermal reaction for preparation of LiCoO2

International Nuclear Information System (INIS)

Jung, Bum-Young; Kang, Hyun-Koo; Jeong, In-Seong; Han, Kyoo-Seung; Lee, Youngil; Choo, Jaebum; Ryu, Kwang Sun

2004-01-01

Layered LiCoO 2 as a cathode material for rechargeable lithium battery is prepared using the acetate self-mixing method. Using this method, the preparation procedure consists of just two steps: spontaneous and homogeneous mixing of molten acetates at 80 deg. C, as well as direct thermal reaction at high temperature without any pulverization, grinding, agglomeration, particle morphology controlling, particle size controlling, and even artificial stirring of reactants. When lithium and cobalt acetates are exposed to the temperature of 80 deg. C, they can be fluidized substances by themselves without any solvents and spontaneously mixed together. In this way, layered LiCoO 2 phase is prepared by just simple heat treatment. The heating at 350 deg. C is interposed to accomplish steady intermediate phase translation without any intermittent cooling. The 7 Li MAS NMR and Raman spectra upon the thermal exposure of the reactants demonstrate the feature of the spontaneous mixing process of the molten reactants. The LiCoO 2 prepared by the acetate self-mixing method show quite prospective properties as a cathode material for lithium rechargeable battery, an initial discharge capacity of 149.5 mAh/g and the discharge capacity retention of 98.9% and 97.5% after 10 and 20 cycles, respectively

Sucrose acetate isobutyrate-based nanogels as liquid fiducial tissue markers with potential use in image guided radiotherapy

DEFF Research Database (Denmark)

Bruun, Linda Maria; Schaarup-Jensen, Henrik; Jølck, Rasmus Irming

The poster presents the development of a liquid fiducial tissue marker based on sucrose acetate isobutyrate (SAIB) and uniform, coated gold nanoparticles (AuNPs). The PNIPAM-coated AuNP-SAIB gel provided high CT contrast and high in vivo stability and was assessed to be a suitable tissue marker f...

Bacteria contributing to behaviour of radiocarbon in sodium acetate

International Nuclear Information System (INIS)

Ishii, N.; Uchida, S.

2011-01-01

An acetate-utilising bacterium was isolated and identified from deionised water that was used for flooding of paddy soils in this study's batch culture experiments. Bacteria in the deionised water samples formed colonies on agar plates containing [1,2- 14 C] sodium acetate, and the autoradiograms showed that all the colonies were positive for 14 C utilisation. Then one of the acetate-utilising bacteria was isolated. The isolate was characterised by phylogenetic analysis, cell morphology, Gram staining and growth at 30 deg. C. Phylogenetic analysis based on 16 S rRNA sequencing showed that the isolate belonged to the genus Burkholderia. The bacterium was gram-negative rods and grew at 30 deg. C under aerobic conditions. Based on these characteristics, the isolate was identified as Burkholderia gladioli. Because B. gladioli is often found in soil, water and the rhizosphere, attention must be paid to the relationships between bacteria and the behaviour of 14 C to for the safety assessment of geological disposal of transuranic waste. (authors)

Effect of acetic acid on rice seeds coated with rice husk ash

Directory of Open Access Journals (Sweden)

Lizandro Ciciliano Tavares

2013-06-01

Full Text Available Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência, five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed and five concentrations of acetic acid (0, 3, 6, 9 and 12 mM, with 4 replications, totaling 50 treatments. The variables first count of germination, germination, shoot and root length, dry weight of shoots and roots were recorded. The results showed that coating rice seeds with rice husk ash up to 5 g kg-1 seed does not influence the performance of rice seeds of cultivars IRGA 424 and BRS Querência when exposed to concentrations of 12 mM acetic acid. The presence of acetic acid in the substrates used for seed germination reduced the vigor and viability of seeds of cultivars IRGA 424 and BRS Querência, as well as seedling development, affecting mainly the roots of BRS Querência.

21 CFR 582.6185 - Calcium acetate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is generally...

Water promoted allylic nucleophilic substitution reactions of (E)-1,3 diphenylallyl acetate

KAUST Repository

Ghorpade, Seema Arun; Sawant, Dinesh N; Makki, Arwa; Sekar, N; Eppinger, Jö rg

2017-01-01

Transition metal free, water based, greener protocol for allylic alkylation, allylic amination, O-allylation of (E)-1,3-diphenylallyl acetate is described. The developed methodology is applicable for a wide range of nucleophiles furnishing excellent yields of corresponding products up to 87% under mild reaction conditions. A Distinct effect of water and base is explored for allylic nucleophilic substitution reactions of (E)-1,3-diphenylallyl acetate.

Water promoted allylic nucleophilic substitution reactions of (E)-1,3 diphenylallyl acetate

KAUST Repository

Ghorpade, Seema Arun

2017-11-30

Transition metal free, water based, greener protocol for allylic alkylation, allylic amination, O-allylation of (E)-1,3-diphenylallyl acetate is described. The developed methodology is applicable for a wide range of nucleophiles furnishing excellent yields of corresponding products up to 87% under mild reaction conditions. A Distinct effect of water and base is explored for allylic nucleophilic substitution reactions of (E)-1,3-diphenylallyl acetate.

Application of Taguchi method for separation of uranium from acetate bearing wastewater using hydroxamic acid based sorbent

International Nuclear Information System (INIS)

Satpati, S.K.; Hareendran, K.; Roy, S.B.; Vaidya, A.; Bankar, V.; Dasgupta, K.; Pal, S.

2016-01-01

Separation and recovery of uranium from effluent of nuclear facility has drawn immense attention in separation science research. The acetic acid based uranium solution effluent generated in uranium metal powder production facility was targeted for the study. Solid state separation technique has been employed using hydroxamic acid based chelating sorbent because of several advantages. In the study, the sorbent performances have been evaluated for its important parameters like isotherm, efficiency and kinetics. The equilibrium adsorption capacity (q e ) and distribution coefficient (K d ) of U(VI) have been evaluated as 3.24 mg/g sorbent and 805 ml/g sorbent respectively. Uranium has been recovered using HCl solution. Uranium removal from the feed was found to be more than 95% and the recovery of uranium was more than 99% from the adsorbed phase. Elution process is faster than sorption process. Taguchi optimization method has been applied for designing experimental study and also to identify the optimum operational conditions for uranium separation process.The developed process is useful for separation and recovery of uranium from acetate bearing wastewater generated in uranium processing facilities

Trapping social wasps (Hymenoptera: Vespidae) with acetic acid and saturated short chain alcohols.

Science.gov (United States)

Landolt, P J; Smithhisler, C S; Reed, H C; McDonough, L M

2000-12-01

Nineteen compounds were evaluated in combination with a solution of acetic acid as baits for trapping the German yellowjacket, Vespula germanica (F.), the western yellowjacket Vespula pensylvanica (Sausssure), and the golden paper wasp Polistes aurifer Saussure. Compounds with three to six carbon chains or branched chains and with a hydroxy functional group were selected for testing based on their similarity to isobutanol. They were compared with isobutanol with acetic acid, which is a known wasp attractant. None of the compounds tested were superior to isobutanol when presented with acetic acid as a lure for these species of wasps. However, traps baited with either the S-(-)- or the racemic mixture of 2-methyl-1-butanol in combination with acetic acid captured similar numbers of both species of yellowjackets, compared with isobutanol with acetic acid. Polistes aurifer responded strongly to the S-(-)-enantiomer and to the racemic mixture of 2-methyl-1-butanol with acetic acid and not to the R-(+)-enantiomer with acetic acid.

Lewis base activation of Lewis acids: catalytic, enantioselective addition of glycolate-derived silyl ketene acetals to aldehydes.

Science.gov (United States)

Denmark, Scott E; Chung, Won-Jin

2008-06-20

A catalytic system involving silicon tetrachloride and a chiral, Lewis basic bisphosphoramide catalyst is effective for the addition of glycolate-derived silyl ketene acetals to aldehydes. It was found that the sense of diastereoselectivity could be modulated by changing the size of the substituents on the silyl ketene acetals. In general, the trimethylsilyl ketene acetals derived from methyl glycolates with a large protecting group on the alpha-oxygen provide enantiomerically enriched alpha,beta-dihydroxy esters with high syn-diastereoselectivity, whereas the tert-butyldimethylsilyl ketene acetals derived from bulky esters of alpha-methoxyacetic acid provide enantiomerically enriched alpha,beta-dihydroxy esters with high anti-diastereoselecitvity.

21 CFR 582.1005 - Acetic acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is generally...

Anhydrous formic acid and acetic anhydride as solvent or additive in nonaqueous titrations.

Science.gov (United States)

Buvári-Barcza, A; Tóth, I; Barcza, L

2005-09-01

The use and importance of formic acid and acetic anhydride (Ac2O) is increasing in nonaqueous acid-base titrations, but their interaction with the solutes is poorly understood. This paper attempts to clarify the effect of the solvents; NMR and spectrophotometric investigations were done to reveal the interactions between some bases and the mentioned solvents. Anhydrous formic acid is a typical protogenic solvent but both the relative permittivity and acidity are higher than those of acetic acid (mostly used in assays of bases). These differences originate from the different chemical structures: liquid acetic acid contains basically cyclic dimers while formic acid forms linear associates. Ac2O is obviously not an acidic but an aprotic (very slightly protophilic) solvent, which supposedly dissociates slightly into acetyl (CH3CO+) and acetate (AcO-) ions. In fact, some bases react with Ac2O forming an associate: the Ac+ group is bound to the delta- charged atom of the reactant while AcO- is associated with the delta+ group at appropriate distance.

Acetate enhances startup of a H₂-producing microbial biocathode.

Science.gov (United States)

Jeremiasse, Adriaan W; Hamelers, Hubertus V M; Croese, Elsemiek; Buisman, Cees J N

2012-03-01

H(2) can be produced from organic matter with a microbial electrolysis cell (MEC). To decrease MEC capital costs, a cathode is needed that is made of low-cost material and produces H(2) at high rate. A microbial biocathode is a low-cost candidate, but suffers from a long startup and a low H(2) production rate. In this study, the effects of cathode potential and carbon source on microbial biocathode startup were investigated. Application of a more negative cathode potential did not decrease the startup time of the biocathode. If acetate instead of bicarbonate was used as carbon source, the biocathode started up more than two times faster. The faster startup was likely caused by a higher biomass yield for acetate than for bicarbonate, which was supported by thermodynamic calculations. To increase the H(2) production rate, a flow through biocathode fed with acetate was investigated. This biocathode produced 2.2 m(3) H(2) m(-3)  reactor day(-1) at a cathode potential of -0.7 V versus NHE, which was seven times that of a parallel flow biocathode of a previous study. Copyright © 2011 Wiley Periodicals, Inc.

Air-oxidized linalyl acetate - an emerging fragrance allergen?

Science.gov (United States)

Hagvall, Lina; Berglund, Victoria; Bråred Christensson, Johanna

2015-04-01

Linalyl acetate is a fragrance chemical that is prone to autoxidation. Exposure to linalyl acetate occurs through cosmetic products and essential oils, but is difficult to assess, as linalyl acetate is not labelled in the EU. To investigate the frequencies of contact allergy to oxidized linalyl acetate among dermatitis patients, and to investigate the autoxidation of linalyl acetate in terms of hydroperoxide formation and sensitization potency. Hydroperoxide formation in air-exposed linalyl acetate was determined with high-performance liquid chromatography. The sensitization potencies of hydroperoxides were determined with the local lymph node assay. One thousand seven hundred and seventeen patients were patch tested with oxidized linalyl acetate at 6.0% in petrolatum. Of the patients, 2.2% showed positive reactions to oxidized linalyl acetate. Forty-three per cent of the positive patients also had positive patch test reactions to other fragrance markers. Linalyl acetate hydroperoxides were detected early in the autoxidation process, and accumulated to a concentration of 37% after 42 weeks of air exposure. The linalyl acetate hydroperoxides were classified as moderate sensitizers. The frequency of positive reactions to oxidized linalyl acetate is comparable to that of previously studied oxidized fragrance terpenes. Oxidized linalyl acetate could thus be a common fragrance contact allergen. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process.

Science.gov (United States)

Ahsan, Laboni; Jahan, M Sarwar; Ni, Yonghao

2014-03-01

This work investigated the feasibility of recovering and concentrating sugars and acetic acid (HAc) from prehydrolysis liquor (PHL) of the kraft-based dissolving pulp process prior to fermentation of hemicellulosic sugars, by the combination of activated carbon adsorption, nanofiltration (NF) and reverse osmosis (RO) processes. To reduce the fouling PHL was subjected to adsorption on activated carbon, then the treated PHL (TPHL) passed through a nanofiltration (NF DK) membrane to retain the sugars, and the permeate of acetic acid rich solution was passed through a reverse osmosis membrane (RO SG). It was found that for NF process sugars were concentrated from 48 to 227g/L at a volume reduction factor (VRF) of 5 while 80 to 90% of acetic acid was permeated. For the reverse osmosis process, 68% of acetic acid retention was achieved at pH 4.3 and 500 psi pressure and the HAc concentration increased from 10 to 50g/L. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Identification of syntrophic acetate-oxidizing bacteria in anaerobic digesters by combined protein-based stable isotope probing and metagenomics.

Science.gov (United States)

Mosbæk, Freya; Kjeldal, Henrik; Mulat, Daniel G; Albertsen, Mads; Ward, Alastair J; Feilberg, Anders; Nielsen, Jeppe L

2016-10-01

Inhibition of anaerobic digestion through accumulation of volatile fatty acids occasionally occurs as the result of unbalanced growth between acidogenic bacteria and methanogens. A fast recovery is a prerequisite for establishing an economical production of biogas. However, very little is known about the microorganisms facilitating this recovery. In this study, we investigated the organisms involved by a novel approach of mapping protein-stable isotope probing (protein-SIP) onto a binned metagenome. Under simulation of acetate accumulation conditions, formations of (13)C-labeled CO2 and CH4 were detected immediately following incubation with [U-(13)C]acetate, indicating high turnover rate of acetate. The identified (13)C-labeled peptides were mapped onto a binned metagenome for improved identification of the organisms involved. The results revealed that Methanosarcina and Methanoculleus were actively involved in acetate turnover, as were five subspecies of Clostridia. The acetate-consuming organisms affiliating with Clostridia all contained the FTFHS gene for formyltetrahydrofolate synthetase, a key enzyme for reductive acetogenesis, indicating that these organisms are possible syntrophic acetate-oxidizing (SAO) bacteria that can facilitate acetate consumption via SAO, coupled with hydrogenotrophic methanogenesis (SAO-HM). This study represents the first study applying protein-SIP for analysis of complex biogas samples, a promising method for identifying key microorganisms utilizing specific pathways.

Identification of syntrophic acetate-oxidizing bacteria in anaerobic digesters by combined protein-based stable isotope probing and metagenomics

Science.gov (United States)

Mosbæk, Freya; Kjeldal, Henrik; Mulat, Daniel G; Albertsen, Mads; Ward, Alastair J; Feilberg, Anders; Nielsen, Jeppe L

2016-01-01

Inhibition of anaerobic digestion through accumulation of volatile fatty acids occasionally occurs as the result of unbalanced growth between acidogenic bacteria and methanogens. A fast recovery is a prerequisite for establishing an economical production of biogas. However, very little is known about the microorganisms facilitating this recovery. In this study, we investigated the organisms involved by a novel approach of mapping protein-stable isotope probing (protein-SIP) onto a binned metagenome. Under simulation of acetate accumulation conditions, formations of 13C-labeled CO2 and CH4 were detected immediately following incubation with [U-13C]acetate, indicating high turnover rate of acetate. The identified 13C-labeled peptides were mapped onto a binned metagenome for improved identification of the organisms involved. The results revealed that Methanosarcina and Methanoculleus were actively involved in acetate turnover, as were five subspecies of Clostridia. The acetate-consuming organisms affiliating with Clostridia all contained the FTFHS gene for formyltetrahydrofolate synthetase, a key enzyme for reductive acetogenesis, indicating that these organisms are possible syntrophic acetate-oxidizing (SAO) bacteria that can facilitate acetate consumption via SAO, coupled with hydrogenotrophic methanogenesis (SAO-HM). This study represents the first study applying protein-SIP for analysis of complex biogas samples, a promising method for identifying key microorganisms utilizing specific pathways. PMID:27128991

Calcination of calcium acetate and calcium magnesium acetate: effect of the reacting atmosphere

Energy Technology Data Exchange (ETDEWEB)

Adanez, J.; Diego, L.F. de; Garcia-Labiano, F. [Instituto de Carboquimica, Zaragoza (Spain). Dept. of Energy and Environment

1999-04-01

The calcination process of the calcium acetate (CA) and calcium magnesium acetate (CMA) was investigated as a previous step for coal gas desulfurisation during sorbent injection at high temperatures because the excellent results demonstrated by these sorbents as sulfur removal agents both in combustion and gasification processes. As pore structure developed during calcination is one of the most important characteristics of the sorbent related with the later reaction with the gaseous pollutants, several calcination tests were conducted in a drop tube reactor at temperatures from 700{degree}C to 1100{degree}C, and residence times from 0.8 to 2.4 s. Four different gas atmospheres were used for comparative purposes: inert, oxidising, reducing, and non-calcining (pure CO{sub 2}). Despite the advantage of the high porous cenospheric structure developed by these sorbents during their injection at high temperature, calcination of the CaCO{sub 3} was not complete even at the longest residence time, 2.4 s, and the highest temperature, 1100{degree}C, tested. An important effect of the reacting atmosphere on the calcination conversion and on the sorbent pore structure was detected. The CO{sub 2} concentration around the particle, both that fed in the reacting gases or that generated by organic material combustion, seems to be responsible for the final calcination conversions obtained in each case, also affecting the sintering suffered by the sorbents. 19 refs., 10 figs.

Simultaneous determination of triacetin, acetic ether, butyl acetate and amorolfine hydrochloride in amorolfine liniment by HPLC.

Science.gov (United States)

Gao, Yuan; Li, Li; Zhang, Jianjun; Shu, Wenjuan; Gao, Liqiong

2012-04-01

A simple, rapid, specific and precise reversed-phase high-performance liquid chromatographic method was developed for simultaneous estimation of triacetin, acetic ether, butyl acetate and amorolfine in marketed pharmaceutical liniment. Chromatographic separation was performed on a Shimadzu VP-ODS C(18) column using the mixture of citric acid-hydrochloric acid-sodium hydrate buffer (pH 3.0), acetonitrile and methanol (32:30:38) as the mobile phase at a flow rate of 1.0 mL/min with UV-detection at 215 nm. The method separated the four components simultaneously in less than 10 min. The validation of the method was performed with respect to specificity, linearity, accuracy, and precision. The calibration curves were linear in the range of 35.1-81.9 μ/mL for triacetin, 431.1-1005.9 μ/mL for acetic ether, 167.0-389.7 μ/mL for butyl acetate and 151.0-352.3 μ/mL for amorolfine. The mean 100% spiked recovery for triacetin, acetic ether, butyl acetate and amorolfine is 99.43 ± 0.42, 101.5 ± 1.09, 101.4 ± 1.02 and 100.8 ± 0.69, respectively. The intra-day and inter-day relative standard deviation values were liniment.

Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

Science.gov (United States)

Senna, Magdy M.; Mostafa, Abo El-Khair B.; Mahdy, Sanna R.; El-Naggar, Abdel Wahab M.

2016-11-01

Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

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

Directory of Open Access Journals (Sweden)

Sá-Correia Isabel

2010-10-01

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

Acetate metabolism in Methanothrix soehngenii

NARCIS (Netherlands)

Jetten, M.S.M.

1991-01-01

Acetate is quantitatively the most important intermediate in the anaerobic degradation of soluble organic matter. The conversion rate of acetate by methanogenic bacteria is proposed to be the rate limiting step in this degradation The study of acetoclastic methanogens, therefore is of

21 CFR 184.1005 - Acetic acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation of...

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

Science.gov (United States)

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

1986-01-01

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

Hydrolyses of alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester

DEFF Research Database (Denmark)

Kirkeby, S; Moe, D

1983-01-01

Using simultaneous coupling azo dye techniques kidney enzymes active against alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester are characterized. The enzymes show identical distribution in the section. The banding patterns in zymograms are the same after...

Acetate formation in the energy metabolism of parasitic helminths and protists.

Science.gov (United States)

Tielens, Aloysius G M; van Grinsven, Koen W A; Henze, Katrin; van Hellemond, Jaap J; Martin, William

2010-03-15

Formation and excretion of acetate as a metabolic end product of energy metabolism occurs in many protist and helminth parasites, such as the parasitic helminths Fasciola hepatica, Haemonchus contortus and Ascaris suum, and the protist parasites, Giardia lamblia, Entamoeba histolytica, Trichomonas vaginalis as well as Trypanosoma and Leishmania spp. In all of these parasites acetate is a main end product of their energy metabolism, whereas acetate formation does not occur in their mammalian hosts. Acetate production might therefore harbour novel targets for the development of new anti-parasitic drugs. In parasites, acetate is produced from acetyl-CoA by two different reactions, both involving substrate level phosphorylation, that are catalysed by either a cytosolic acetyl-CoA synthetase (ACS) or an organellar acetate:succinate CoA-transferase (ASCT). The ACS reaction is directly coupled to ATP synthesis, whereas the ASCT reaction yields succinyl-CoA for ATP formation via succinyl-CoA synthetase (SCS). Based on recent work on the ASCTs of F. hepatica, T. vaginalis and Trypanosoma brucei we suggest the existence of three subfamilies of enzymes within the CoA-transferase family I. Enzymes of these three subfamilies catalyse the ASCT reaction in eukaryotes via the same mechanism, but the subfamilies share little sequence homology. The CoA-transferases of the three subfamilies are all present inside ATP-producing organelles of parasites, those of subfamily IA in the mitochondria of trypanosomatids, subfamily IB in the mitochondria of parasitic worms and subfamily IC in hydrogenosome-bearing parasites. Together with the recent characterisation among non-parasitic protists of yet a third route of acetate formation involving acetate kinase (ACK) and phosphotransacetylase (PTA) that was previously unknown among eukaryotes, these recent developments provide a good opportunity to have a closer look at eukaryotic acetate formation. (c) 2010 Australian Society for Parasitology

Synthesis and characterization of composite based on cellulose acetate and hydroxyapatite application to the absorption of harmful substances.

Science.gov (United States)

Azzaoui, Khalil; Lamhamdi, Abdelatif; Mejdoubi, El Miloud; Berrabah, Mohammed; Hammouti, Belkheir; Elidrissi, Abderrahman; Fouda, Moustafa M G; Al-Deyab, Salem S

2014-10-13

The aim of this work is to develop composite materials with hydroxyapatite (HAp) mineral and organic matrix such as cellulosic polymers. We use cellulose acetate with different percentages, and then inorganic-organic films were fabricated by evaporation of solvent. The composite films were characterized using emission scanning electron microscopy (FEG-SEM), thermo-gravimetric analysis (TGA) and Fourier transform infra-red (FT-IR) spectra. Test results show that these films are uniform and have good ductility. A strong interaction existed between HAp and cellulosic polymers, and the method allows the production of very fine particles size of about 92 nm. We have developed a new chromatographic method for the quantification of bisphenol A (BPA) in samples of baby food. The result of this study demonstrates how to use this type of composite materials to remove pollutants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Captive solvent [11C]acetate synthesis in GMP conditions

International Nuclear Information System (INIS)

Soloviev, Dmitri; Tamburella, Claire

2006-01-01

Reliable procedure for the production of 1-[ 11 C]acetate in GMP conditions was developed based on a combination of the captive-solvent Grignard reaction conducted in the sterile catheter followed by the convenient solid-phase extraction purification on a series of ion-exchange cartridges. The described procedure proved to be reliable in more than 30 patient productions. The process provides stable radiochemical yields (65% EOB) of sodium acetate (1-[ 11 C]) of the Ph.Eur. quality (radiochemical purity better than 95%) in a short time (5 min)

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

International Nuclear Information System (INIS)

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

2006-01-01

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)

Low and high acetate amendments are equally as effective at promoting complete dechlorination of trichloroethylene (TCE).

Science.gov (United States)

Wei, Na; Finneran, Kevin T

2013-06-01

Experiments with trichloroethylene-contaminated aquifer material demonstrated that TCE, cis-DCE, and VC were completely degraded with concurrent Fe(III) or Fe(III) and sulfate reduction when acetate was amended at stoichiometric concentration; competing TEAPs did not inhibit ethene production. Adding 10× more acetate did not increase the rate or extent of TCE reduction, but only increased methane production. Enrichment cultures demonstrated that ~90 μM TCE or ~22 μM VC was degraded primarily to ethene within 20 days with concurrent Fe(III) or Fe(III) + sulfate reduction. The dechlorination rates were comparable between the low and high acetate concentrations (0.36 vs 0.34 day(-1), respectively), with a slightly slower rate in the 10× acetate amended incubations. Methane accumulated to 13.5 (±0.5) μmol/tube in the TCE-degrading incubations with 10× acetate, and only 1.4 (±0.1) μmol/tube with low acetate concentration. Methane accumulated to 16 (±1.5) μmol/tube in VC-degrading enrichment with 10× acetate and 2 (±0.1) μmol/tube with stoichiometric acetate. The estimated fraction of electrons distributed to methanogenesis increased substantially when excessive acetate was added. Quantitative PCR analysis indicated that 10× acetate did not enhance Dehalococcoides biomass but rather increased the methanogen abundance by nearly one order of magnitude compared to that with stoichiometric acetate. The data suggest that adding low levels of substrate may be equally if not more effective as high concentrations, without producing excessive methane. This has implications for field remediation efforts, in that adding excess electron donor may not benefit the reactions of interest, which in turn will increase treatment costs without direct benefit to the stakeholders.

Electrospinning of Nano-Porous Cellulose Acetate Fibers Under Humidified Condition

Directory of Open Access Journals (Sweden)

Hamid Fattahi Juybari

2016-01-01

Full Text Available Electrospinning as a simple method was used to produce cellulose acetate porous fibers. Motivation for production of fibers with small diameter in the submicron and nano scales was to achieve the material with a large surfacearea with porosity formation in the structure of electrospun fibers. In this study, porous cellulose acetate (CA fibers were produced by electrospinning process from solution of CA/acetone/water. The porosity of the fiber was controlled by adjustment of the temperature and humidity of electrospinning chamber. Scanning electron microscopy (SEM and densitometry were employed to evaluate the morphology and porosity of the samples. The results showed that the morphology and porosity of cellulose acetate fibers depend on the polymer solution concentration and relative humidity of electrospinning atmosphere. Cellulose acetate fibers were electrospun best at the concentrations of 12 to 18 wt% and relative humidity range of 40 to 80%. The highest porosity was obtained at the relative humidity of 80% and concentration of 15 wt%. In addition, by increasing the relative humidity of electrospinning environment and polymer concentration, the average diameter of the fibers was increased. With increasing the polymer concentration, there was less likelihood in thermodynamic instability and phase separation. In contrast, increases in relative humidity led to diffusion of more water into the electrospinning jet, giving rise to phase separation. Our observations revealed that the skin of fibers was formed at the earlier stage of the process and prevented the stretch in electrospinning jet.

Graphene-Fiber-Based Supercapacitors Favor N-Methyl-2-pyrrolidone/Ethyl Acetate as the Spinning Solvent/Coagulant Combination.

Science.gov (United States)

He, Nanfei; Pan, Qin; Liu, Yixin; Gao, Wei

2017-07-26

One-dimensional flexible fiber supercapacitors (FSCs) have attracted great interest as promising energy-storage units that can be seamlessly incorporated into textiles via weaving, knitting, or braiding. The major challenges in this field are to develop tougher and more efficient FSCs with a relatively easy and scalable process. Here, we demonstrate a wet-spinning process to produce graphene oxide (GO) fibers from GO dispersions in N-methyl-2-pyrrolidone (NMP), with ethyl acetate as the coagulant. Upon chemical reduction of GO, the resulting NMP-based reduced GO (rGO) fibers (rGO@NMP-Fs) are twice as high in the surface area and toughness but comparable in tensile strength and conductivity as that of the water-based rGO fibers (rGO@H 2 O-Fs). When assembled into parallel FSCs, rGO@NMP-F-based supercapacitors (rGO@NMP-FSCs) offered a specific capacitance of 196.7 F cm -3 (147.5 mF cm -2 ), five times higher than that of rGO@H 2 O-F-based supercapacitors (rGO@H 2 O-FSCs) and also higher than most existing wet-spun rGO-FSCs, as well as those FSCs built with metal wires, graphene/carbon nanotube (CNT) fibers, or even pseudocapacitive materials. In addition, our rGO@NMP-FSCs can provide good bending and cycling stability. The energy density of our rGO@NMP-FSCs reaches ca. 6.8 mWh cm -3 , comparable to that of a Li thin-film battery (4 V/500 μAh).

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

Science.gov (United States)

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

1988-01-01

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

Insights into the mechanism of acetic acid hydrogenation to ethanol on Cu(111) surface

International Nuclear Information System (INIS)

Zhang, Minhua; Yao, Rui; Jiang, Haoxi; Li, Guiming; Chen, Yifei

2017-01-01

Highlights: • The scission of C–OH bond of acetic acid is the rate-determined step in acetic acid hydrogenation to ethanol on Cu(111). • Acetic acid adsorption and reaction barrier of C–OH scission of acetic acid are factors related to acetic acid conversion. • Acetaldehyde adsorption and reaction barriers of O–H formation of C_2–oxygenates are factors related to ethanol selectivity. - Abstract: Density functional theory (DFT) calculations were employed to theoretically explain the reaction mechanism of acetic acid hydrogenation to ethanol on Cu catalyst. The activation barriers of key elementary steps and the adsorption configurations of key intermediates involved in acetic acid hydrogenation on Cu(111) surface were investigated. The results indicated that the direct dissociation of acetic acid to acetyl (CH_3COOH → CH_3CO + OH) is the rate-determined step. The activation barrier of acetic acid scission to acetyl and the adsorption energy of acetic acid are two descriptors which could determine the conversion of acetic acid. The descriptors might have effects on the ethanol selectivity including: the adsorption energy of acetaldehyde and the activation barriers for O−H bond formation of C_2-oxygenates (CH_3CO + H → CH_3COH, CH_3CHO + H → CH_3CHOH and CH_3CH_2O + H → CH_3CH_2OH). These proposed descriptors could be used as references to design new Cu-based catalysts that have excellent catalytic performance.

Employing natural reagents from turmeric and lime for acetic acid determination in vinegar sample

Directory of Open Access Journals (Sweden)

Sam-ang Supharoek

2018-04-01

Full Text Available A simple, rapid and environmentally friendly sequential injection analysis system employing natural extract reagents was developed for the determination of acetic acid following an acid–base reaction in the presence of an indicator. Powdered lime and turmeric were utilized as the natural base and indicator, respectively. Mixing lime and turmeric produced an orange to reddish-brown color solution which absorbed the maximum wavelength at 455 nm, with absorbance decreasing with increasing acetic acid concentration. Influential parameters including lime and turmeric concentrations, reagent and sample aspirated volumes, mixing coil length and dispensing flow rate were investigated and optimized. A standard calibration graph was plotted for 0–5.0 mmol/L acetic acid with r2 = 0.9925. Relative standard deviations (RSD at 2.0 and 4.0 mmol/L acetic acid were less than 3% (n = 7, with limit of detection (LOD and limit of quantification (LOQ at 0.12 and 0.24 mmol/L, respectively. The method was successfully applied to assay acetic acid concentration in cooking vinegar samples. Results achieved were not significantly different from those obtained following a batchwise standard AOAC titration method. Keywords: Acetic acid assay, Natural reagent, Turmeric, Lime, Sequential injection analysis

21 CFR 182.8892 - α-Tocopherol acetate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true α-Tocopherol acetate. 182.8892 Section 182.8892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...-Tocopherol acetate. (a) Product. α-Tocopherol acetate. (b) Conditions of use. This substance is generally...

Models construction for acetone-butanol-ethanol fermentations with acetate/butyrate consecutively feeding by graph theory.

Science.gov (United States)

Li, Zhigang; Shi, Zhongping; Li, Xin

2014-05-01

Several fermentations with consecutively feeding of acetate/butyrate were conducted in a 7 L fermentor and the results indicated that exogenous acetate/butyrate enhanced solvents productivities by 47.1% and 39.2% respectively, and changed butyrate/acetate ratios greatly. Then extracellular butyrate/acetate ratios were utilized for calculation of acids rates and the results revealed that acetate and butyrate formation pathways were almost blocked by corresponding acids feeding. In addition, models for acetate/butyrate feeding fermentations were constructed by graph theory based on calculation results and relevant reports. Solvents concentrations and butanol/acetone ratios of these fermentations were also calculated and the results of models calculation matched fermentation data accurately which demonstrated that models were constructed in a reasonable way. Copyright © 2014 Elsevier Ltd. All rights reserved.

Glatiramer Acetate-associated Refractory Immune Thrombocytopenic Purpura

Directory of Open Access Journals (Sweden)

Iftach Sagy

2016-04-01

Full Text Available We present a case of glatiramer acetate-associated refractory immune thrombocytopenic purpura (ITP in a female patient with multiple sclerosis. A search of MEDLINE/PubMed did not find any connection between glatiramer acetate and thrombocytopenia, specifically ITP. The autoimmune reaction was resistant to conservative ITP treatment, and was eventually managed only by splenectomy. To the best of our knowledge, this is the first report of glatiramer acetate-associated ITP. Physicians should be aware of this condition, and consider performing routine blood counts at the beginning of glatiramer acetate treatment.

Treating carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

Corbett, R L; Corbett, E G

1939-03-21

A process is given for the production of aliphatic compounds by heat treatment of carbonaceous material. The latter are impregnated with a dilute solution of a catalyst, such as chromium copper or nickel acetate or nitrate, or ammonium or urea acetate and subjected to destructive distillation in a retort in the presence of a reducing gas and steam, at a pressure not greater than fifteen atmospheres.

Porosity and density measurements of sodium acetate trihydrate for thermal energy storage

DEFF Research Database (Denmark)

Dannemand, Mark; Delgado, Monica; Lazaro, Ana

2018-01-01

Sodium acetate trihydrate (SAT) can be used as phase change material in latent heat storage with or without utilizing supercooling. The change of density between liquid to solid state leads to formation of cavities inside the bulk SAT during solidification. Samples of SAT which had solidified from...

Vapour pressures and vapour-liquid equilibria of propyl acetate and isobutyl acetate with ethanol or 2-propanol at 0.15 MPa. Binary systems

Directory of Open Access Journals (Sweden)

Susial Pedro

2012-01-01

Full Text Available Vapour pressures of propyl acetate, isobutyl acetate and 2-propanol from 0.004 to 1.6 MPa absolute pressure and VLE data for the binary systems propyl acetate+ethanol, propyl acetate+2-propanol, isobutyl acetate+ethanol and isobutyl acetate+2-propanol at 0.15 MPa have been determined. The experimental VLE data were verified with the test of van Ness and the Fredenslund criterion. The propyl acetate+ethanol or +2-propanol binary systems have an azeotropic point at 0.15 MPa. The different versions of the UNIFAC and ASOG group contribution models were applied.

Synthesis of acetic acid via methanol hydrocarboxylation with CO2 and H2

OpenAIRE

Qian, Qingli; Zhang, Jingjing; Cui, Meng; Han, Buxing

2016-01-01

Acetic acid is an important bulk chemical that is currently produced via methanol carbonylation using fossil based CO. Synthesis of acetic acid from the renewable and cheap CO2 is of great importance, but state of the art routes encounter difficulties, especially in reaction selectivity and activity. Here we report a route to produce acetic acid from CO2, methanol and H2. The reaction can be efficiently catalysed by Ru?Rh bimetallic catalyst using imidazole as the ligand and LiI as the promot...

21 CFR 582.5892 - a-Tocopherol acetate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false a-Tocopherol acetate. 582.5892 Section 582.5892 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5892 a-Tocopherol acetate. (a) Product. a-Tocopherol acetate. (b) Conditions of use. This...

Electrodeposition of CdTe thin film from acetate-based ionic liquid bath

Science.gov (United States)

Waldiya, Manmohansingh; Bhagat, Dharini; Mukhopadhyay, Indrajit

2018-05-01

CdTe being a direct band gap semiconductor, is mostly used in photovoltaics. Here we present, the synthesis of CdTe thin film on fluorine doped tin oxide (FTO) substrate potentiostatically using 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]) ionic liquid (IL) bath at 90 °C. Major advantages of using electrodeposition involves process simplicity, large scalability & economic viability. Some of the benefits offered by IL electrolytic bath are low vapour pressure, wide electrochemical window, and good ionic mobility. Cd(CH3COO)2 (anhydrous) and TeO2 were used as the source precursors. The IL electrolytic bath temperature was kept at 90 °C for deposition, owing to the limited solubility of TeO2 in [Bmim][Ac] IL at room temperature. Cathodic electrodeposition was carried out using a three electrode cell setup at a constant potential of -1.20 V vs. platinum (Pt) wire. The CdTe/FTO thin film were annealed in argon (Ar) atmosphere. Optical study of nanostructured CdTe film were done using UV-Vis-IR and Raman spectroscopy. Raman analysis confirms the formation of CdTe having surface optics (SO) mode at 160.6 cm-1 and transverse optics (TO) mode at 140.5 cm-1. Elemental Te peaks at 123, 140.5 and 268 cm-1 were also observed. The optical band gap of Ar annealed CdTe thin film were found to be 1.47 eV (absorbance band edge ˜ 846 nm). The optimization of deposition parameters using acetate-based IL electrolytic bath to get nearly stoichiometric CdTe thin film is currently being explored.

Antibiofilm Properties of Acetic Acid

DEFF Research Database (Denmark)

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

2014-01-01

Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the inf......Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal...... of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram......-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms....

Insights into the mechanism of acetic acid hydrogenation to ethanol on Cu(111) surface

Energy Technology Data Exchange (ETDEWEB)

Zhang, Minhua; Yao, Rui; Jiang, Haoxi; Li, Guiming [Key Laboratory for Green Chemical Technology of Ministry of Education, R& D Center for Petrochemical Technology, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China); Chen, Yifei, E-mail: yfchen@tju.edu.cn [Key Laboratory for Green Chemical Technology of Ministry of Education, R& D Center for Petrochemical Technology, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China)

2017-08-01

Highlights: • The scission of C–OH bond of acetic acid is the rate-determined step in acetic acid hydrogenation to ethanol on Cu(111). • Acetic acid adsorption and reaction barrier of C–OH scission of acetic acid are factors related to acetic acid conversion. • Acetaldehyde adsorption and reaction barriers of O–H formation of C{sub 2}–oxygenates are factors related to ethanol selectivity. - Abstract: Density functional theory (DFT) calculations were employed to theoretically explain the reaction mechanism of acetic acid hydrogenation to ethanol on Cu catalyst. The activation barriers of key elementary steps and the adsorption configurations of key intermediates involved in acetic acid hydrogenation on Cu(111) surface were investigated. The results indicated that the direct dissociation of acetic acid to acetyl (CH{sub 3}COOH → CH{sub 3}CO + OH) is the rate-determined step. The activation barrier of acetic acid scission to acetyl and the adsorption energy of acetic acid are two descriptors which could determine the conversion of acetic acid. The descriptors might have effects on the ethanol selectivity including: the adsorption energy of acetaldehyde and the activation barriers for O−H bond formation of C{sub 2}-oxygenates (CH{sub 3}CO + H → CH{sub 3}COH, CH{sub 3}CHO + H → CH{sub 3}CHOH and CH{sub 3}CH{sub 2}O + H → CH{sub 3}CH{sub 2}OH). These proposed descriptors could be used as references to design new Cu-based catalysts that have excellent catalytic performance.

Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

International Nuclear Information System (INIS)

Rapp, F.; Schneider, A.; Elsner, P.

2014-01-01

Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO 2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength)

Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

Science.gov (United States)

Rapp, F.; Schneider, A.; Elsner, P.

2014-05-01

Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength).

Investigation of ATR-FTIR spectroscopy as an alternative to the Water Leach Free Acidity test for cellulose acetate-based film

DEFF Research Database (Denmark)

Johansen, Karin Bonde; Shashoua, Yvonne

2005-01-01

Cellulose acetate film loses acetate groups on ageing which results in the formation of damaging acetic acid. Water-Leach Free Acidity Test (WLFAT) is the definitive technique to quantify acidity, but requires 1g film and 26 hours. ATR-FTIR spectroscopy is a non-destructive, rapid technique which...

The influence of surface oxygen and hydroxyl groups on the dehydrogenation of ethylene, acetic acid and hydrogenated vinyl acetate on pure Pd(1 0 0): A DFT study

Energy Technology Data Exchange (ETDEWEB)

Huang, Yanping [Key Laboratory for Green Chemical Technology of Ministry of Education, R& D Center for Petrochemical Technology, Tianjin University, Tianjin (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China); Dong, Xiuqin [Key Laboratory for Green Chemical Technology of Ministry of Education, R& D Center for Petrochemical Technology, Tianjin University, Tianjin (China); Yu, Yingzhe, E-mail: yzhyu@tju.edu.cn [Key Laboratory for Green Chemical Technology of Ministry of Education, R& D Center for Petrochemical Technology, Tianjin University, Tianjin (China); Zhang, Minhua, E-mail: mhzhangtj@163.com [Key Laboratory for Green Chemical Technology of Ministry of Education, R& D Center for Petrochemical Technology, Tianjin University, Tianjin (China)

2016-12-01

Highlights: • All dehydrogenation reactions in vinyl acetate synthesis on Pd(1 0 0) were studied. • The energy barriers of the transition state of the three reactions were calculated. • The influence of surface Os and OHs on all dehydrogenation actions was discussed. - Abstract: On the basis of a Langmuir–Hinshelwood-type mechanism, the dehydrogenation of ethylene, acetic acid and hydrogenated vinyl acetate (VAH) on pure Pd(1 0 0) with surface oxygen atoms (Os) and hydroxyl groups (OHs) was studied with density functional theory (DFT) method. Our calculation results show that both Os and OHs can consistently reduce the activation energies of dehydrogenation of ethylene, acetic acid and VAH to some degree with only one exception that OHs somehow increase the activation energy of VAH. Based on Langmuir–Hinshelwood mechanism, the three dehydrogenation reactions in presence of surface Os and OHs are almost consistently favored, compared with the corresponding processes on clean Pd(1 0 0) surfaces, and thus a Langmuir–Hinshelwood-type mechanism may not be excluded beforehand when investigating the microscopic performance of the oxygen-assisted vinyl acetate synthesis on Pd(1 0 0) catalysts.

Omics analysis of acetic acid tolerance in Saccharomyces cerevisiae.

Science.gov (United States)

Geng, Peng; Zhang, Liang; Shi, Gui Yang

2017-05-01

Acetic acid is an inhibitor in industrial processes such as wine making and bioethanol production from cellulosic hydrolysate. It causes energy depletion, inhibition of metabolic enzyme activity, growth arrest and ethanol productivity losses in Saccharomyces cerevisiae. Therefore, understanding the mechanisms of the yeast responses to acetic acid stress is essential for improving acetic acid tolerance and ethanol production. Although 329 genes associated with acetic acid tolerance have been identified in the Saccharomyces genome and included in the database ( http://www.yeastgenome.org/observable/resistance_to_acetic_acid/overview ), the cellular mechanistic responses to acetic acid remain unclear in this organism. Post-genomic approaches such as transcriptomics, proteomics, metabolomics and chemogenomics are being applied to yeast and are providing insight into the mechanisms and interactions of genes, proteins and other components that together determine complex quantitative phenotypic traits such as acetic acid tolerance. This review focuses on these omics approaches in the response to acetic acid in S. cerevisiae. Additionally, several novel strains with improved acetic acid tolerance have been engineered by modifying key genes, and the application of these strains and recently acquired knowledge to industrial processes is also discussed.

Effect of acetic acid on wet patterning of copper/molybdenum thin films in phosphoric acid solution

International Nuclear Information System (INIS)

Seo, Bo.-Hyun; Lee, Sang-Hyuk; Park, In-Sun; Seo, Jong Hyun; Choe, HeeHwan; Jeon, Jae-Hong; Hong, Munpyo; Lee, Yong Uk; Winkler, Joerg

2011-01-01

Copper metallization is a key issue for high performance thin film transistor (TFT) technology. A phosphoric acid based copper etchant is a potentially attractive alternative to the conventional hydrogen peroxide based etchant due to its longer-life expectancy time and higher stability in use. In this paper, it is shown that amount of the acetic acid in the phosphoric based copper etchant plays an important role in controlling the galvanic reaction between the copper and the molybdenum. As the concentration of acetic acid in the phosphoric mixture solution increased from 0 M to 0.4 M, the measured galvanic current density dropped from 32 mA/cm 2 to 26 mA/cm 2 , indicating that the acetic acid induces the lower galvanic reaction between the copper and the molybdenum in the solution. From the XPS analysis, with the addition of the acetic acid, the thickness of the protective MoO 2 passive film covering the molybdenum surface grew and the dissolution rate of the molybdenum thin film decreased. However, the dissolution rate of the copper thin film increased as the concentration of acetic acid in the mixture solution increased.

Effect of acetic acid on wet patterning of copper/molybdenum thin films in phosphoric acid solution

Energy Technology Data Exchange (ETDEWEB)

Seo, Bo.-Hyun; Lee, Sang-Hyuk; Park, In-Sun [Department of Materials Engineering, Korea Aerospace University, Hwajeon, Goyang, Gyonggi-do 412-791 (Korea, Republic of); Seo, Jong Hyun, E-mail: jhseo@kau.ac.kr [Department of Materials Engineering, Korea Aerospace University, Hwajeon, Goyang, Gyonggi-do 412-791 (Korea, Republic of); Choe, HeeHwan; Jeon, Jae-Hong [School of Electronics, Telecommunications and Computer Engineering, Korea Aerospace University, Hwajeon, Goyang, Gyonggi-do 412-791 (Korea, Republic of); Hong, Munpyo [Display and Semiconductor Physics, Korea University (Korea, Republic of); Lee, Yong Uk [PETEC (The Printable Electronics Technology Centre) (United Kingdom); Winkler, Joerg [PLANSEE Metal GmbH, Metallwerk-Plansee-Str. 71A-6600, Reutte (Austria)

2011-08-01

Copper metallization is a key issue for high performance thin film transistor (TFT) technology. A phosphoric acid based copper etchant is a potentially attractive alternative to the conventional hydrogen peroxide based etchant due to its longer-life expectancy time and higher stability in use. In this paper, it is shown that amount of the acetic acid in the phosphoric based copper etchant plays an important role in controlling the galvanic reaction between the copper and the molybdenum. As the concentration of acetic acid in the phosphoric mixture solution increased from 0 M to 0.4 M, the measured galvanic current density dropped from 32 mA/cm{sup 2} to 26 mA/cm{sup 2}, indicating that the acetic acid induces the lower galvanic reaction between the copper and the molybdenum in the solution. From the XPS analysis, with the addition of the acetic acid, the thickness of the protective MoO{sub 2} passive film covering the molybdenum surface grew and the dissolution rate of the molybdenum thin film decreased. However, the dissolution rate of the copper thin film increased as the concentration of acetic acid in the mixture solution increased.

Practical Stannylation of Allyl Acetates Catalyzed by Nickel with Bu3 SnOMe.

Science.gov (United States)

Komeyama, Kimihiro; Itai, Yuuhei; Takaki, Ken

2016-06-27

A practical and scalable nickel-catalyzed allylic stannylation of allyl acetates with Bu3 SnOMe is described. A variety of acyclic and cyclic allyl acetates, even with base-sensitive moieties, undergoes the stannylation by using NiBr2 /4,4'-di-tert-butylbipyridine (dtbpy)/Mn catalyst system to afford highly functionalized allyl stannanes with excellent regioselectivity and yields. Furthermore, the scope of protocol is also extended by the reaction of propargyl acetates, giving rise to propargyl or allenyl stannanes. Additionally, a unique diastereoselectivity using the nickel catalyst different from the palladium was demonstrated for the stannylation of cyclic allyl acetates. In the reaction, inexpensive and stable nickel complexes, abundant reductant (Mn), and atom-economical stannyl source were used. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanocomposite photoactuators based on an ethylene vinyl acetate copolymer filled with carbon nanotubes

Czech Academy of Sciences Publication Activity Database

Czaniková, K.; Torras, N.; Esteve, J.; Krupa, I.; Kasák, P.; Pavlova, Ewa; Račko, D.; Chodák, I.; Omastová, M.

2013-01-01

Roč. 186, September (2013), s. 701-710 ISSN 0925-4005 Institutional support: RVO:61389013 Keywords : actuator * carbon nanotubes * ethylene vinyl acetate copolymer Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.840, year: 2013

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

DEFF Research Database (Denmark)

Gorbanev, Yury; Kegnæs, Søren; Hanning, Christopher William

2012-01-01

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...

Lead Acetate Based Hybrid Perovskite Through Hot Casting for Planar Heterojunction Solar Cells

Science.gov (United States)

Shin, Gwang Su; Choi, Won-Gyu; Na, Sungjae; Gökdemir, Fatma Pinar; Moon, Taeho

2018-03-01

Flawless coverage of a perovskite layer is essential in order to achieve realistic high-performance planar heterojunction solar cells. We present that high-quality perovskite layers can be efficiently formed by a novel hot casting route combined with MAI (CH3NH3I) and non-halide lead acetate (PbAc2) precursors under ambient atmosphere. Casting temperature is controlled to produce various perovskite microstructures and the resulted crystalline layers are found to be comprised of closely packed islands with a smooth surface structure. Lead acetate employed perovskite solar cells are fabricated using PEDOT:PSS and PCBM charge transporting layers, in p- i- n type planar architecture. Especially, the outstanding open-circuit voltage demonstrates the high crystallinity and dense coverage of the produced perovskite layers by this facile route.

Fixing of metallic acetates on an anion-exchange resin; Fixation d'acetates metalliques dans une resine echangeuse d'anions

Energy Technology Data Exchange (ETDEWEB)

Brigaudeau-Vaissiere, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etude Nucleaires

1966-06-01

After giving a brief review of the theoretical principles governing the fixation of anionic complexes of metallic elements on an anion exchange resin, we consider the particular case of uranyl acetate. By plotting the partition curves we have been able to calculate the exchange constants in the resin. By studying the changes in the logarithm of the limiting partition coefficient as a function of the logarithm of the free acetate ion concentration, it has been possible to calculate the dissociation constants for the complexes in solution. The fixation of a large number of metallic acetates has been studied. All the tests have been negative except in the case of mercury. For this reason we have been able to consider the possibility of separating uranium from a certain number of elements. Some of these separations are possible even in the presence of interfering anions such as chlorides which have a greater affinity for the resin than have the acetate ions. In the case of water-ethanol and water-isopropanol mixtures, we have improved the conditions under which copper acetate and mercury acetate may be fixed. This study has enabled us to calculate the dissociation constant for the CuAc{sub 3}{sup -} complex in the mixtures water +40% (by weight) isopropanol and water +50% (by weight) isopropanol. It should also make it possible to use separation conditions which could not hitherto be applied in aqueous media. (author) [French] Apres avoir rappele les principes theoriques de la fixation des complexes anioniques des elements metalliques dans une resine echangeuse d'anions, nous avons etudie tout particulierement le cas de l'acetate d'uranyle. Le trace des courbes de partage nous a permis de calculer les constantes d'echange dans la resine. L'etude des variations du logarithme du coefficient limite de partage avec le logarithme de la concentration des ions acetate libres nous a conduits aux calculs des constantes de dissociation des complexes en solution. La fixation d

Insights into the mechanism of acetic acid hydrogenation to ethanol on Cu(111) surface

Science.gov (United States)

Zhang, Minhua; Yao, Rui; Jiang, Haoxi; Li, Guiming; Chen, Yifei

2017-08-01

Density functional theory (DFT) calculations were employed to theoretically explain the reaction mechanism of acetic acid hydrogenation to ethanol on Cu catalyst. The activation barriers of key elementary steps and the adsorption configurations of key intermediates involved in acetic acid hydrogenation on Cu(111) surface were investigated. The results indicated that the direct dissociation of acetic acid to acetyl (CH3COOH → CH3CO + OH) is the rate-determined step. The activation barrier of acetic acid scission to acetyl and the adsorption energy of acetic acid are two descriptors which could determine the conversion of acetic acid. The descriptors might have effects on the ethanol selectivity including: the adsorption energy of acetaldehyde and the activation barriers for Osbnd H bond formation of C2-oxygenates (CH3CO + H → CH3COH, CH3CHO + H → CH3CHOH and CH3CH2O + H → CH3CH2OH). These proposed descriptors could be used as references to design new Cu-based catalysts that have excellent catalytic performance.

Glycerol transesterification with ethyl acetate to synthesize acetins using ethyl acetate as reactant and entrainer

Directory of Open Access Journals (Sweden)

Amin Shafiei

2017-03-01

Full Text Available Transesterification of glycerol with ethyl acetate was performed over acidic catalysts in the batch and semi-batch systems. Ethyl acetate was used as reactant and entrainer to remove the produced ethanol during the reaction, through azeotrope formation. Since the azeotrope of ethyl acetate and ethanol forms at 70 oC, all the experiments were performed at this temperature. Para-toluene sulfonic acid, sulfuric acid, and Amberlyst 36 were used as catalyst. The effect of process parameters including ethyl acetate to glycerol molar ratio (6-12, reaction time (3-9 h, and the catalyst to glycerol weight (2.5-9.0%, on the conversion and products selectivities were investigated. Under reflux conditions, 100% glycerol conversion was obtained with 45%, 44%, and 11% selectivity to monoacetin, diacetin, and triacetin, respectively. Azeotropic reactive distillation led to 100% conversion of glycerol with selectivities of 3%, 48% and 49% for monoacetin, diacetin, and triacetin. During the azeotropic reactive distillation, it was possible to remove ethanol to shift the equilibrium towards diacetin and triacetin. Therefore, the total selectivity to diacetin and triacetin was increased from 55% to 97% through azeotropic distillation.

Fermentation characteristics of Fusarium oxysporum grown on acetate

DEFF Research Database (Denmark)

Panagiotou, Gianni; Pachidou, Fotini; Petroutsos, Dimitris

2008-01-01

In this study, the growth characteristics of Fusarium oxysporum were evaluated in minimal medium using acetate or different mixtures of acetate and glucose as carbon source. The minimum inhibitory concentration (MIC) of acetic acid that F oxysporum cells could tolerate was 0.8% w/v while glucose ...

Modification of wheat starch with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures I. Thermophysical and pasting properties.

Science.gov (United States)

Subarić, Drago; Ačkar, Durđica; Babić, Jurislav; Sakač, Nikola; Jozinović, Antun

2014-10-01

The aim of this research was to investigate the influence of modification with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures on thermophysical and pasting properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetic anhydride, and azelaic acid and acetic anhydride in 4, 6 and 8 % (w/w). Thermophysical, pasting properties, swelling power, solubility and amylose content of modified starches were determined. The results showed that modifications with mixtures of afore mentioned dicarboxylic acids with acetic anhydride decreased gelatinisation and pasting temperatures. Gelatinisation enthalpy of Golubica starch increased, while of Srpanjka starch decreased by modifications. Retrogradation after 7 and 14 day-storage at 4 °C decreased after modifications of both starches. Maximum, hot and cold paste viscosity of both starches increased, while stability during shearing at high temperatures decreased. % setback of starches modified with azelaic acid/acetic anhydride mixture decreased. Swelling power and solubility of both starches increased by both modifications.

Interaction of dispersed polyvynil acetate with silicate in finishing materials

Directory of Open Access Journals (Sweden)

Runova, R. F.

1996-12-01

Full Text Available This article focuses on the processes of interaction between calcium silicate hydrates and dispersed polyvinyl acetate in tight films with the aim of developing compounds meant for restoration and finishing works. The basis of this development relies on the concept concerning the determining role of the crystal-chemical factor of the silicate phase in the formation of organic-mineral compounds of increased durability. The characteristics of dispersed calcium silicate hydrates are portrayed. The preparation conditions, accounting for the synthesis of the product of submicrocrystalline structure, conforming with the stoichiometry CaO∙SiO₂ =0.8-2.0 have been determined. The interaction has been studied for compounds achieved by mixing ingredients in a rapid whirling mixer, and subjected to hardening at T=20+2 T. With the aid of XRD, DTA and Infra-Red Spectrometry methods the formation process of the sophisticated polymer silicate phase in the material was observed for a period of 90 days. The properties of the film were investigated and its high resistance against the influence of external factors was established. On this basis a conclusion concerning the quite high effectiveness of substituting portland cement with dispersed calcium silicate hydrate in polymer cement compounds has been made. White colour and other various special properties determine the suitability for repair and finishing works on facades of buildings.

Este artículo está orientado a estudiar los procesos de interacción entre los silicatos cálcicos hidratados y el acetato de polivinilo disperso en capas impermeables, con el objeto de desarrollar compuestos destinados para la restauración. El fundamento de estos estudios es determinar el papel que los factores cristaloquímicos de las fases silicato tienen en la formación de compuestos órganominerales de elevada durabilidad. Se han descrito las características de los silicatos cálcicos hidratados

Influence of calcium acetate on rye bread volume

Directory of Open Access Journals (Sweden)

Katharina FUCKERER

2016-01-01

Full Text Available Abstract The positive accepted savoury taste of rye bread is dependent on acetate concentration in the dough of such breads. In order to study how calcium acetate influences rye bread properties, the pH of rye doughs fortified with calcium acetate and the resulting volume of the breads were measured. Furthermore, CO2 formation of yeast with added calcium acetate and yeast with different pH levels (4, 7, 9 were measured. Thereby, it was determined that the addition of calcium acetate increased the pH of dough from 4.42 to 5.29 and significantly reduced the volume of the breads from 1235.19 mL to 885.52 mL. It could be proven that bread volume was affected by a 30.9% lower CO2 amount production of yeast, although bread volume was not affected by changing pH levels. Due to reduced bread volume, high concentrations of calcium acetate additions are not recommended for improving rye bread taste.

Histopathological Alterations after Single Epidural Injection of Ropivacaine, Methylprednizolone Acetate, or Contrast Material in Swine

International Nuclear Information System (INIS)

Kitsou, Maria-Chrysanthi; Kostopanagiotou, Georgia; Kalimeris, Konstantinos; Vlachodimitropoulos, Demetrios; Soultanis, Konstantinos; Batistaki, Chrysanthi; Kelekis, Alexis

2011-01-01

Purpose: The consequences from the injection of different types of drugs in the epidural space remains unknown. Increasing evidence suggests that localized inflammation, fibrosis, and arachnoiditis can complicate sequential epidural blockades, or even epidural contrast injection. We investigate the in vivo effect of epidural injections in the epidural space in an animal model. Materials and Methods: A group of ten male adult pigs, five punctures to each at distinct vertebral interspaces under general anesthesia, were examined, testing different drugs, used regularly in the epidural space (iopamidol, methylprednisolone acetate, ropivacaine). Each site was marked with a percutaneous hook wire marker. Histological analysis of the epidural space, the meninges, and the underlying spinal cord of the punctured sites along with staining for caspase-3 followed 20 days later. Results: The epidural space did not manifest adhesions or any other pathology, and the outer surface of the dura was not impaired in any specimen. The group that had the contrast media injection showed a higher inflammation response compared to the other groups (P = 0.001). Positive staining for caspase-3 was limited to <5% of neurons with all substances used. Conclusion: No proof of arachnoiditis and/or fibrosis was noted in the epidural space with the use of the above-described drugs. A higher inflammation rate was noted with the use of contrast media.

Study of alkaline-earth element complexes in anhydrous acetic acid

International Nuclear Information System (INIS)

Petit, N.

1968-10-01

We have studied the complexes of alkaline-earth elements in anhydrous acetic acid. Using glass-electrode potentiometry we have studied the titration of alkaline earth acetates with perchloric acid which is the strongest acid in anhydrous acetic acid. These titrations have shown that the basic strength of these acetates increases as follows: Mg 4 ); the mixed acetate-acid sulfate complex of barium: Ba (OAc)(HSO 4 ); the mixed acetate-chloride of barium: Ba (OAc)(Cl). (author) [fr

Employing natural reagents from turmeric and lime for acetic acid determination in vinegar sample.

Science.gov (United States)

Supharoek, Sam-Ang; Ponhong, Kraingkrai; Siriangkhawut, Watsaka; Grudpan, Kate

2018-04-01

A simple, rapid and environmentally friendly sequential injection analysis system employing natural extract reagents was developed for the determination of acetic acid following an acid-base reaction in the presence of an indicator. Powdered lime and turmeric were utilized as the natural base and indicator, respectively. Mixing lime and turmeric produced an orange to reddish-brown color solution which absorbed the maximum wavelength at 455 nm, with absorbance decreasing with increasing acetic acid concentration. Influential parameters including lime and turmeric concentrations, reagent and sample aspirated volumes, mixing coil length and dispensing flow rate were investigated and optimized. A standard calibration graph was plotted for 0-5.0 mmol/L acetic acid with r 2  = 0.9925. Relative standard deviations (RSD) at 2.0 and 4.0 mmol/L acetic acid were less than 3% (n = 7), with limit of detection (LOD) and limit of quantification (LOQ) at 0.12 and 0.24 mmol/L, respectively. The method was successfully applied to assay acetic acid concentration in cooking vinegar samples. Results achieved were not significantly different from those obtained following a batchwise standard AOAC titration method. Copyright © 2017. Published by Elsevier B.V.

Detoxification of biomass derived acetate via metabolic conversion to ethanol, acetone, isopropanol, or ethyl acetate

Science.gov (United States)

Sillers, William Ryan; Van Dijken, Hans; Licht, Steve; Shaw, IV, Arthur J.; Gilbert, Alan Benjamin; Argyros, Aaron; Froehlich, Allan C.; McBride, John E.; Xu, Haowen; Hogsett, David A.; Rajgarhia, Vineet B.

2017-03-28

One aspect of the invention relates to a genetically modified thermophilic or mesophilic microorganism, wherein a first native gene is partially, substantially, or completely deleted, silenced, inactivated, or down-regulated, which first native gene encodes a first native enzyme involved in the metabolic production of an organic acid or a salt thereof, thereby increasing the native ability of said thermophilic or mesophilic microorganism to produce lactate or acetate as a fermentation product. In certain embodiments, the aforementioned microorganism further comprises a first non-native gene, which first non-native gene encodes a first non-native enzyme involved in the metabolic production of lactate or acetate. Another aspect of the invention relates to a process for converting lignocellulosic biomass to lactate or acetate, comprising contacting lignocellulosic biomass with a genetically modified thermophilic or mesophilic microorganism.

21 CFR 177.1350 - Ethylene-vinyl acetate copolymers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate copolymers. 177.1350 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1350 Ethylene-vinyl acetate copolymers. Ethylene-vinyl acetate copolymers may be safely used as articles or components of articles...

Synthesis and crystal structure analysis of uranyl triple acetates

Energy Technology Data Exchange (ETDEWEB)

Klepov, Vladislav V., E-mail: vladislavklepov@gmail.com [Institute for Energy and Climate Research (IEK-6), Forschungszentrum Jülich GmbH, 52428 Jülich (Germany); Department of Chemistry, Samara National Research University, 443086 Samara (Russian Federation); Serezhkina, Larisa B.; Serezhkin, Victor N. [Department of Chemistry, Samara National Research University, 443086 Samara (Russian Federation); Alekseev, Evgeny V., E-mail: e.alekseev@fz-juelich.de [Institute for Energy and Climate Research (IEK-6), Forschungszentrum Jülich GmbH, 52428 Jülich (Germany); Institut für Kristallographie, RWTH Aachen University, 52066 Aachen (Germany)

2016-12-15

Single crystals of triple acetates NaR[UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 3}·6H{sub 2}O (R=Mg, Co, Ni, Zn), well-known for their use as reagents for sodium determination, were grown from aqueous solutions and their structural and spectroscopic properties were studied. Crystal structures of the mentioned phases are based upon (Na[UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 3}){sup 2–} clusters and [R(H{sub 2}O){sub 6}]{sup 2+} aqua-complexes. The cooling of a single crystal of NaMg[UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 3}·6H{sub 2}O from 300 to 100 K leads to a phase transition from trigonal to monoclinic crystal system. Intermolecular interactions between the structural units and their mutual packing were studied and compared from the point of view of the stereoatomic model of crystal structures based on Voronoi-Dirichlet tessellation. Using this method we compared the crystal structures of the triple acetates with Na[UO{sub 2}(CH{sub 3}COO){sub 3}] and [R(H{sub 2}O){sub 6}][UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 2} and proposed reasons of triple acetates stability. Infrared and Raman spectra were collected and their bands were assigned. - Graphical abstract: Single crystals of uranium based triple acetates, analytical reagents for sodium determination, were synthesized and structurally, spectroscopically and topologically characterized. The structures were compared with the structures of compounds from preceding families [M(H{sub 2}O){sub 6})][UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 2} (M = Mg, Co, Ni, Zn) and Na[UO{sub 2}(CH{sub 3}COO){sub 3}]. Analysis was performed with the method of molecular Voronoi-Dirichlet polyhedra to reveal a large contribution of the hydrogen bonds into intermolecular interactions which can be a reason of low solubility of studied complexes.

Desmopressin Acetate in Intracranial Haemorrhage

Directory of Open Access Journals (Sweden)

Thomas Kapapa

2014-01-01

Full Text Available Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N=4 or multiple (N=6 doses of acetylsalicylic acid and 3 patients (control group who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P≤0.05. Results. (1 Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2 The platelet function worsened again after three hours. (3 There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients.

LDEF materials data bases

Science.gov (United States)

Funk, Joan G.; Strickland, John W.; Davis, John M.

1993-01-01

The Long Duration Exposure Facility (LDEF) and the accompanying experiments were composed of and contained a wide variety of materials representing the largest collection of materials flown in low Earth orbit (LEO) and retrieved for ground based analysis to date. The results and implications of the mechanical, thermal, optical, and electrical data from these materials are the foundation on which future LEO space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been charged with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the spacecraft user community in an easily accessed, user-friendly form. This paper discusses the format and content of the three data bases developed or being developed to accomplish this task. The hardware and software requirements for each of these three data bases are discussed along with current availability of the data bases. This paper also serves as a user's guide to the MAPTIS LDEF Materials Data Base.

The Effects of Lead Acetate on Sexual Behavior and the Level of Testosterone in Adult Male Rats

Directory of Open Access Journals (Sweden)

Mokhtar Mokhtari

2011-01-01

Full Text Available Background: In the present study, the oral effect of lead acetate on the parameters related to sexualbehavior as well as changes in the level of testosterone hormone in adult male rats have beeninvestigated.Materials and Methods: Forty adult male Wistar rats were allocated into five equal groups. Thecontrol group received nothing, the sham group received distilled water and the experimentalgroups received 25, 50 and 100mg/kg lead acetate orally, respectively for 28 days. The changesin testosterone hormone level and following sexual behavior parameters were investigated: mountlatency (ML, intromission latency (IL, post ejaculatory interval (PEI, mount frequency (MF,ejaculatory latency (EL, intromission frequency (IF, copulatory efficacy (CE and intercopulatoryinterval (ICI.Results: The levels of testosterone hormone in the groups that received 50 and 100 mg/kg leadacetate showed significant decreases in compared to the control group. Additionally, the same dosesof lead acetate caused significant increases in ML, IL, PEI and EL compared to the control group.No significant change was observed in MF, but a significant decrease was detected in IF and CEin the experimental group that received 100 mg/kg lead acetate when compared with the controlgroup. ICI showed significant decreases in the experimental groups that received 50 and 100 mg/kglead acetate compared to the control group.Conclusion: It can be concluded that ingestion of lead acetate affects some behavioral activitiesand the testosterone level of male rats. These effects might be conducted via the alteration of leydigcells following lead acetate poisoning.

Short-term effect of acetate and ethanol on methane formation in biogas sludge.

Science.gov (United States)

Refai, Sarah; Wassmann, Kati; Deppenmeier, Uwe

2014-08-01

Biochemical processes in biogas plants are still not fully understood. Especially, the identification of possible bottlenecks in the complex fermentation processes during biogas production might provide potential to increase the performance of biogas plants. To shed light on the question which group of organism constitutes the limiting factor in the anaerobic breakdown of organic material, biogas sludge from different mesophilic biogas plants was examined under various conditions. Therefore, biogas sludge was incubated and analyzed in anaerobic serum flasks under an atmosphere of N2/CO2. The batch reactors mirrored the conditions and the performance of the full-scale biogas plants and were suitable test systems for a period of 24 h. Methane production rates were compared after supplementation with substrates for syntrophic bacteria, such as butyrate, propionate, or ethanol, as well as with acetate and H2+CO2 as substrates for methanogenic archaea. Methane formation rates increased significantly by 35 to 126 % when sludge from different biogas plants was supplemented with acetate or ethanol. The stability of important process parameters such as concentration of volatile fatty acids and pH indicate that ethanol and acetate increase biogas formation without affecting normally occurring fermentation processes. In contrast to ethanol or acetate, other fermentation products such as propionate, butyrate, or H2 did not result in increased methane formation rates. These results provide evidence that aceticlastic methanogenesis and ethanol-oxidizing syntrophic bacteria are not the limiting factor during biogas formation, respectively, and that biogas plant optimization is possible with special focus on methanogenesis from acetate.

Addressing a Common Misconception: Ammonium Acetate as Neutral pH "Buffer" for Native Electrospray Mass Spectrometry

Science.gov (United States)

Konermann, Lars

2017-09-01

Native ESI-MS involves the transfer of intact proteins and biomolecular complexes from solution into the gas phase. One potential pitfall is the occurrence of pH-induced changes that can affect the analyte while it is still surrounded by solvent. Most native ESI-MS studies employ neutral aqueous ammonium acetate solutions. It is a widely perpetuated misconception that ammonium acetate buffers the analyte solution at neutral pH. By definition, a buffer consists of a weak acid and its conjugate weak base. The buffering range covers the weak acid pKa ± 1 pH unit. NH4 + and CH3-COO- are not a conjugate acid/base pair, which means that they do not constitute a buffer at pH 7. Dissolution of ammonium acetate salt in water results in pH 7, but this pH is highly labile. Ammonium acetate does provide buffering around pH 4.75 (the pKa of acetic acid) and around pH 9.25 (the pKa of ammonium). This implies that neutral ammonium acetate solutions electrosprayed in positive ion mode will likely undergo acidification down to pH 4.75 ± 1 in the ESI plume. Ammonium acetate nonetheless remains a useful additive for native ESI-MS. It is a volatile electrolyte that can mimic the solvation properties experienced by proteins under physiological conditions. Also, a drop from pH 7 to around pH 4.75 is less dramatic than the acidification that would take place in pure water. It is hoped that the habit of referring to pH 7 solutions as ammonium acetate "buffer" will disappear from the literature. Ammonium acetate "solution" should be used instead. [Figure not available: see fulltext.

In situ acetate separation in microbial electrosynthesis from CO

NARCIS (Netherlands)

Bajracharya, Suman; Burg, van den Bart; Vanbroekhoven, Karolien; Wever, De Heleen; Buisman, Cees J.N.; Pant, Deepak; Strik, David P.B.T.B.

2017-01-01

Bioelectrochemical reduction of carbon dioxide (CO₂) to multi-carbon organic compounds particularly acetate has been achieved in microbial electrosynthesis (MES) using the reducing equivalents produced at the electrically polarized cathode. MES based on CO₂ reduction

Aerobic oxidation of aqueous ethanol using heterogeneous gold catalysts: Efficient routes to acetic acid and ethyl acetate

DEFF Research Database (Denmark)

Jørgensen, Betina; Christiansen, Sofie Egholm; Thomsen, M.L.D.

2007-01-01

The aerobic oxidation of aqueous ethanol to produce acetic acid and ethyl acetate was studied using heterogeneous gold catalysts. Comparing the performance of Au/MgAl2O4 and Au/TiO2 showed that these two catalysts exhibited similar performance in the reaction. By proper selection of the reaction...

Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge

OpenAIRE

Ito, Tsukasa; Yoshiguchi, Kazumi; Ariesyady, Herto Dwi; Okabe, Satoshi

2011-01-01

Major acetate-utilizing bacterial and archaeal populations in methanogenic anaerobic digester sludge were identified and quantified by radioisotope- and stable-isotope-based functional analyses, microautoradiography-fluorescence in situ hybridization (MAR-FISH) and stable-isotope probing of 16S rRNA (RNA-SIP) that can directly link 16S rRNA phylogeny with in situ metabolic function. First, MAR-FISH with 14C-acetate indicated the significant utilization of acetate by only two major groups, uni...

Steam Reforming of Acetic Acid over Co-Supported Catalysts: Coupling Ketonization for Greater Stability

Energy Technology Data Exchange (ETDEWEB)

Davidson, Stephen D. [Energy and Environmental; Spies, Kurt A. [Energy and Environmental; Mei, Donghai [Energy and Environmental; Kovarik, Libor [Energy and Environmental; Kutnyakov, Igor [Energy and Environmental; Li, Xiaohong S. [Energy and Environmental; Lebarbier Dagle, Vanessa [Energy and Environmental; Albrecht, Karl O. [Energy and Environmental; Dagle, Robert A. [Energy and Environmental

2017-09-11

We report on the markedly improved stability of a novel 2-bed catalytic system, as compared to a conventional 1-bed steam reforming catalyst, for the production of H2 from acetic acid. The 2-bed catalytic system comprises of i) a basic oxide ketonization catalyst for the conversion of acetic acid to acetone, and a ii) Co-based steam reforming catalyst, both catalytic beds placed in sequence within the same unit operation. Steam reforming catalysts are particularly prone to catalytic deactivation when steam reforming acetic acid, used here as a model compound for the aqueous fraction of bio-oil. Catalysts comprising MgAl2O4, ZnO, CeO2, and activated carbon (AC) both with and without Co-addition were evaluated for conversion of acetic acid and acetone, its ketonization product, in the presence of steam. It was found that over the bare oxide support only ketonization activity was observed and coke deposition was minimal. With addition of Co to the oxide support steam reforming activity was facilitated and coke deposition was significantly increased. Acetone steam reforming over the same Co-supported catalysts demonstrated more stable performance and with less coke deposition than with acetic acid feedstock. DFT analysis suggests that over Co surface CHxCOO species are more favorably formed from acetic acid versus acetone. These CHxCOO species are strongly bound to the Co catalyst surface and could explain the higher propensity for coke formation from acetic acid. Based on these findings, in order to enhance stability of the steam reforming catalyst a dual-bed (2-bed) catalyst system was implemented. Comparing the 2-bed and 1-bed (Co-supported catalyst only) systems under otherwise identical reaction conditions the 2-bed demonstrated significantly improved stability and coke deposition was decreased by a factor of 4.

Theoretical problems associated with the use of acetic anhydride as a co-solvent for the non-aqueous titration of hydrohalides of organic bases and quaternary ammonium salts.

Science.gov (United States)

Völgyi, Gergely; Béni, Szabolcs; Takács-Novák, Krisztina; Görög, Sándor

2010-01-05

A potentiometric titration study of organic base hydrohalides and quaternary ammonium salts using perchloric acid as the titrant and a mixture of acetic anhydride and acetic acid as the solvent was carried out and the titration mixture was analysed by NMR in order to clarify the chemistry of the reactions involved. It was found that in contrast to the general belief the formation of acetyl halides and titratable free acetate ion does not take place prior to the titration but NMR spectra proved the formation of acetyl halides in the course of the titration. This observation and the fact that the shape of the titration curves depends on the nature of the hydrohaloic acid bound to the base or of the anion in the quaternary ammonium salts led to the conclusion that the titrating agent is acetyl perchlorate formed in situ during the titration. Equations of the reactions involved in the titration process are shown in the paper.

Vinyl acetate polymerization by ionizing radiation

International Nuclear Information System (INIS)

Mesquita, Andrea Cercan

2002-01-01

The aim of this work is the synthesis and characterization of the poly(vinyl acetate) using the ionizing radiation. Six polymerizations of vinyl acetate were carried out using three techniques of polymerization: in bulk, emulsion and solution. In the technique of solution polymerization were used two solvents, the alcohol ethyl and the methylethylketone, in two proportions 1:0.5 and 1:1 related to the monomer. The solutions were irradiated with gamma rays from a 60 Co source, with dose rate between 5.25 kGy/h and 6.26 kGy/h. The polymers obtained were characterized by Fourier Transform Infrared Spectroscopy (FTIR). The glass transition temperature (Tg) was investigated by Differential Scanning Calorimeter (DSC). The molecular weight was analyzed by the technique of Gel Permeation Chromatography (GPC). Tests of density, hardness and Vicat softening temperature were carried out. The infrared spectroscopy and others results confirmed that the polymers obtained by polymerization of vinyl acetate in bulk, emulsion and solution, using ionizing radiation, really correspond at poly(vinyl acetate). (author)

Aqueous-Phase Acetic Acid Ketonization over Monoclinic Zirconia

Energy Technology Data Exchange (ETDEWEB)

Cai, Qiuxia [Institute for Integrated Catalysis, Pacific Northwest; College; Lopez-Ruiz, Juan A. [Institute for Integrated Catalysis, Pacific Northwest; Cooper, Alan R. [Institute for Integrated Catalysis, Pacific Northwest; Wang, Jian-guo [College; Albrecht, Karl O. [Institute for Integrated Catalysis, Pacific Northwest; Mei, Donghai [Institute for Integrated Catalysis, Pacific Northwest

2017-12-13

The effect of aqueous phase on the acetic acid ketonization over monoclinic zirconia has been investigated using first-principles based density functional theory (DFT) calculations. To capture the aqueous phase chemistry over the solid zirconia catalyst surface, the aqueous phase is represented by 111 explicit water molecules with a liquid water density of 0.93 g/cm3 and the monoclinic zirconia is modeled by the most stable surface structure . The dynamic nature of aqueous phase/ interface was studied using ab initio molecular dynamics simulation, indicating that nearly half of the surface Zr sites are occupied by either adsorbed water molecules or hydroxyl groups at 550 K. DFT calculations show that the adsorption process of acetic acid from the liquid water phase to the surface is nearly thermodynamically neutral with a Gibbs free energy of -2.3 kJ/mol although the adsorption strength of acetic acid on the surface in aqueous phase is much stronger than in vapor phase. Therefore it is expected that the adsorption of acetic acid will dramatically affects aqueous phase ketonization reactivity over the monoclinic zirconia catalyst. Using the same ketonization mechanism via the β-keto acid intermediate, we have compared acetic acid ketonization to acetone in both vapor and aqueous phases. Our DFT calculation results show although the rate-determining step of the β-keto acid formation via the C-C coupling is not pronouncedly affected, the presence of liquid water molecules will dramatically affect dehydrogenation and hydrogenation steps via proton transfer mechanism. This work was financially supported by the United States Department of Energy (DOE)’s Bioenergy Technologies Office (BETO) and performed at the Pacific Northwest National Laboratory (PNNL). PNNL is a multi-program national laboratory operated for DOE by Battelle Memorial Institute. Computing time and advanced catalyst characterization use was granted by a user proposal at the William R. Wiley

Biotechnological applications of acetic acid bacteria.

Science.gov (United States)

Raspor, Peter; Goranovic, Dusan

2008-01-01

The acetic acid bacteria (AAB) have important roles in food and beverage production, as well as in the bioproduction of industrial chemicals. In recent years, there have been major advances in understanding their taxonomy, molecular biology, and physiology, and in methods for their isolation and identification. AAB are obligate aerobes that oxidize sugars, sugar alcohols, and ethanol with the production of acetic acid as the major end product. This special type of metabolism differentiates them from all other bacteria. Recently, the AAB taxonomy has been strongly rearranged as new techniques using 16S rRNA sequence analysis have been introduced. Currently, the AAB are classified in ten genera in the family Acetobacteriaceae. AAB can not only play a positive role in the production of selected foods and beverages, but they can also spoil other foods and beverages. AAB occur in sugar- and alcohol-enriched environments. The difficulty of cultivation of AAB on semisolid media in the past resulted in poor knowledge of the species present in industrial processes. The first step of acetic acid production is the conversion of ethanol from a carbohydrate carried out by yeasts, and the second step is the oxidation of ethanol to acetic acid carried out by AAB. Vinegar is traditionally the product of acetous fermentation of natural alcoholic substrates. Depending on the substrate, vinegars can be classified as fruit, starch, or spirit substrate vinegars. Although a variety of bacteria can produce acetic acid, mostly members of Acetobacter, Gluconacetobacter, and Gluconobacter are used commercially. Industrial vinegar manufacturing processes fall into three main categories: slow processes, quick processes, and submerged processes. AAB also play an important role in cocoa production, which represents a significant means of income for some countries. Microbial cellulose, produced by AAB, possesses some excellent physical properties and has potential for many applications. Other

Heterotrophic and mixotrophic growth of Micractinium pusillum Fresenius in the presence of acetate and glucose: effect of light and acetate gradient concentration.

Science.gov (United States)

Bouarab, L; Dauta, A; Loudiki, M

2004-06-01

The main objective of this study was to determine the importance of secondary mechanism of organic carbon utilization (mixotrophic and heterotrophic modes) in addition to CO2 fixation (photoautotrophic mode) in the green alga, Micractinium pusillum Fresenius (chlorophyta), isolated from a waste stabilization pond. The growth was studied in the presence of acetate and glucose. The incorporation rate of 14C- acetate was measured in the light and in the dark at different concentrations. Finally, in order to underline the role of photosynthesis and respiration processes in the acetate assimilation, the effect of two specific metabolic inhibitors, a specific inhibitor of photosystem II (DCMU) and an uncoupler respiratory (DNP), has been studied. The obtained results showed that M. pusillum grows in the presence of organic substrates, i.e., glucose and acetate, in the light (mixotrophic growth) as well as in the dark (Heterotrophic growth). The growth was much more important in the light than in the dark and more in the presence of glucose than of acetate. In the light, the presence of acetate led to a variation of growth parameters mumax, iotaopt, and beta. The effect of acetate gradient on the growth of the microalga was severe as soon as its concentration in the medium was higher. The acetate uptake followed a Michaelis-Menten kinetic in the light as well as in the dark. The capacity of assimilation was slightly higher in the dark. The utilization of DNP and DCMU indicates that acetate incorporation is an active process depending on both anabolic (photosynthesis) and catabolic (respiration) metabolisms, corroborating the model of the Michaelis-Menten kinetic.

Indole-3-acetic acid/diol based pH-sensitive biological macromolecule for antibacterial, antifungal and antioxidant applications.

Science.gov (United States)

G, Chitra; D S, Franklin; S, Sudarsan; M, Sakthivel; S, Guhanathan

2017-02-01

Indole-3-acetic acid (IAA)/diol based pH-sensitive biopolymeric hydrogels with tunable biological properties (cytotoxicity, anti-oxidant and anti-fungal) have been synthesized via condensation polymerization. The present study focused on the synthesis of heterocyclic hydrogel using citric acid (CA), indole-3-acetic acid (IAA) and diethylene glycol (DEG) by condensation polymerization. The hydrogels revealed a pH-sensitive swelling behaviour, with increased swelling in acidic media, then turns to decreased the swelling in the basic media. The hydrogel samples were tested for antifungal activity against Aspergillus fumigates, Rhizopusoryzae and Candida albicans at different concentrations using ketoconazole as positive control and DMSO as negative control for antifungal activity. Antioxidant activity increasing nature in DPPH than NO radical compared with rutin and confirmed non toxic property using cytotoxicity analysis. The biopolymeric hydrogels were characterized by Fourier transform infrared (FT-IR) spectroscopy, 1 H NMR, 13 C NMR, TGA, DSC followed by scanning electron microscopy (SEM). Such hydrogels with antioxidant properties is recommended for medical applications such as bandages, catheters, drains and tubes to prevent infection. Copyright © 2016 Elsevier B.V. All rights reserved.

Methanogenesis from acetate by Methanosarcina barkeri: Catalysis of acetate formation from methyl iodide, CO/sub 2/, and H/sub 2/ by the enzyme system involved

Energy Technology Data Exchange (ETDEWEB)

Laufer, K; Eikmanns, B; Frimmer, U; Thauer, R K

1987-04-01

Cell suspensions of Methanosarcina barkeri grown on acetate catalyze the formation of methane and CO/sub 2/ from acetate as well as an isotopic exchange between the carboxyl group of acetate and CO/sub 2/. Here we report that these cells also mediate the synthesis of acetate from methyl iodide, CO/sub 2/, and reducing equivalents (H/sub 2/ or CO), the methyl group of acetate being derived from methyl iodide and the carboxyl group from CO/sub 2/. Methyl chloride and methyltosylate but not methanol can substitute for methyl iodide in this reaction. Acetate formation from methyl iodide, CO/sub 2/, and reducing equivalents is coupled with the phosphorylation of ADP. Evidence is presented that methyl iodide is incorporated into the methyl group of acetate via a methyl corrinoid intermediate (deduced from inhibition experiments with propyl iodide) and that CO/sub 2/ is assimilated into the carboxyl group via a C/sub 1/ intermediate which does not exchange with free formate or free CO. The effects of protonophores, of the proton-translocating ATPase inhibitor N,N'-dicyclohexylcarbodiimide, and of arsenate on acetate formation are interpreted to indicate that the reduction of CO/sub 2/ to the oxidation level of the carboxyl group of acetate requires the presence of an electrochemical proton potential and that acetyl-CoA or acetyl-phosphate rather than free acetate is the immediate product of the condensation reaction. These results are dicsussed with respect to the mechanism of methanogenesis from acetate.

Ulipristal acetate versus placebo for fibroid treatment before surgery.

Science.gov (United States)

Donnez, Jacques; Tatarchuk, Tetyana F; Bouchard, Philippe; Puscasiu, Lucian; Zakharenko, Nataliya F; Ivanova, Tatiana; Ugocsai, Gyula; Mara, Michal; Jilla, Manju P; Bestel, Elke; Terrill, Paul; Osterloh, Ian; Loumaye, Ernest

2012-02-02

The efficacy and safety of oral ulipristal acetate for the treatment of symptomatic uterine fibroids before surgery are uncertain. We randomly assigned women with symptomatic fibroids, excessive uterine bleeding (a score of >100 on the pictorial blood-loss assessment chart [PBAC, an objective assessment of blood loss, in which monthly scores range from 0 to >500, with higher numbers indicating more bleeding]) and anemia (hemoglobin level of ≤10.2 g per deciliter) to receive treatment for up to 13 weeks with oral ulipristal acetate at a dose of 5 mg per day (96 women) or 10 mg per day (98 women) or to receive placebo (48 women). All patients received iron supplementation. The coprimary efficacy end points were control of uterine bleeding (PBAC score of <75) and reduction of fibroid volume at week 13, after which patients could undergo surgery. At 13 weeks, uterine bleeding was controlled in 91% of the women receiving 5 mg of ulipristal acetate, 92% of those receiving 10 mg of ulipristal acetate, and 19% of those receiving placebo (P<0.001 for the comparison of each dose of ulipristal acetate with placebo). The rates of amenorrhea were 73%, 82%, and 6%, respectively, with amenorrhea occurring within 10 days in the majority of patients receiving ulipristal acetate. The median changes in total fibroid volume were -21%, -12%, and +3% (P=0.002 for the comparison of 5 mg of ulipristal acetate with placebo, and P=0.006 for the comparison of 10 mg of ulipristal acetate with placebo). Ulipristal acetate induced benign histologic endometrial changes that had resolved by 6 months after the end of therapy. Serious adverse events occurred in one patient during treatment with 10 mg of ulipristal acetate (uterine hemorrhage) and in one patient during receipt of placebo (fibroid protruding through the cervix). Headache and breast tenderness were the most common adverse events associated with ulipristal acetate but did not occur significantly more frequently than with placebo

Acetate production from whey lactose using co-immobilized cells of homolactic and homoacetic bacteria in a fibrous-bed bioreactor

Energy Technology Data Exchange (ETDEWEB)

Huang, Y.; Yang, S.T. [Ohio State Univ., Columbus, OH (United States). Dept. of Chemical Engineering

1998-11-20

Acetate was produced from whey lactose in batch and fed-batch fermentations using co-immobilized cells of Clostridium formicoaceticum and Lactococcus lactis. The cells were immobilized in a spirally wound fibrous sheet packed in a 0.45-L column reactor, with liquid circulated through a 5-L stirred-tank fermentor. Industrial-grade nitrogen sources, including corn steep liquor, casein hydrolysate, and yeast hydrolysate, were studied as inexpensive nutrient supplements to whey permeate and acid whey. Supplementation with either 2.5% (v/v) corn steep liquor or 1.5 g/L casein hydrolysate was adequate for the cocultured fermentation. The overall acetic acid yield from lactose was 0.9 g/g, and the productivity was 0.25 g/(L h). Both lactate and acetate at high concentrations inhibited the homoacetic fermentation. To overcome these inhibitions, fed-batch fermentations were used to keep lactate concentration low and to adapt cells to high-concentration acetate. The final acetate concentration obtained in the fed-batch fermentations were used to keep lactate concentration low and to adapt cells to high-concentration acetate. The final acetate concentration obtained in the fed-batch fermentation was 75 g/L, which was the highest acetate concentration ever produced by C. formicoaceticum. Even at this high acetate concentration, the overall productivity was 0.18 g/(L h) based on the total medium volume and 1.23 g/(L h) based on the fibrous-bed reactor volume. The cells isolated from the fibrous-bed bioreactor at the end of this study were more tolerant to acetic acid than the original culture used to seed the bioreactor, indicating that adaptation and natural selection of acetate-tolerant strains occurred. This cocultured fermentation process could be used to produce a low-cost acetate deicer from whey permeate and acid whey.

Optical Sensor based Chemical Modification as a Porous Cellulose Acetate Film and Its Application for Ethanol Sensor

Science.gov (United States)

Mulijani, S.; Iswantini, D.; Wicaksono, R.; Notriawan, D.

2018-03-01

A new approach to design and construction of an optical ethanol sensor has been developed by immobilizing a direct dye at a porous cellulosic polymer fllm. This sensor was fabricated by binding Nile Red to a cellulose acetate membrane that had previously been subjected to an exhaustive base hydrolysis. The prepared optical ethanol sensor was enhanced by adding pluronic as a porogen in the membrane. The addition of pluronic surfactant into cellulose acetate membrane increased the hydrophilic and porous properties of membrane. Advantageous features of the design include simple and easy of fabrication. Variable affecting sensor performance of dye concentration have been fully evaluated and optimized. The rapid response results from the porous structure of the polymeric support, which minimizes barriers to mass transport. Signal of optical sensor based on reaction of dye nile red over the membrane with ethanol and will produce the purple colored product. Result was obtained that maximum intensity of dye nile red reacted with alcohol is at 630-640 nm. Linear regression equation (r2), limit of detection, and limit of quantitation of membrane with 2% dye was 0.9625, 0.29%, and 0.97%. Performance of optical sensor was also evaluated through methanol, ethanol and propanol. This study was purposed to measure the polarity and selectivity of optic sensor toward the alcohol derivatives. Fluorescence intensity of optic sensor membrane for methanol 5%, ethanol 5% and propanol 5% was 15113.56, 16573.75 and 18495.97 respectively.

Enzymatic production of biodiesel from microalgal oil using ethyl acetate as an acyl acceptor.

Science.gov (United States)

Alavijeh, Razieh Shafiee; Tabandeh, Fatemeh; Tavakoli, Omid; Karkhane, Aliasghar; Shariati, Parvin

2015-01-01

Microalgae have become an important source of biomass for biodiesel production. In enzymatic transesterification reaction, the enzyme activity is decreased in presence of alcohols. The use of different acyl acceptors such as methyl/ethyl acetate is suggested as an alternative and effective way to overcome this problem. In this study, ethyl acetate was used for the first time in the enzymatic production of biodiesel by using microalga, Chlorella vulgaris, as a triglyceride source. Enzymatic conversion of such fatty acids to biodiesel was catalyzed by Novozym 435 as an efficient immobilized lipase which is extensively used in biodiesel production. The best conversion yield of 66.71% was obtained at the ethyl acetate to oil molar ratio of 13:1 and Novozym 435 concentration of 40%, based on the amount of oil, and a time period of 72 h at 40℃. The results showed that ethyl acetate have no adverse effect on lipase activity and the biodiesel amount was not decreased even after seven transesterification cycles, so ethyl acetate has a great potential to be substituted for short-chain alcohols in transesterification reaction.

In situ oligomerization of 2-(thiophen-3-yl)acetate intercalated into Zn{sub 2}Al layered double hydroxide

Energy Technology Data Exchange (ETDEWEB)

Tronto, Jairo, E-mail: jairotronto@ufv.br [Universidade Federal de Viçosa, Instituto de Ciências Exatas e Tecnológicas, Campus de Rio Parsanaíba, Rodovia BR 354 km 310, Cx. Postal 22, CEP, 38.810-000 Rio Paranaíba, MG (Brazil); Pinto, Frederico G.; Costa, Liovando M. da [Universidade Federal de Viçosa, Instituto de Ciências Exatas e Tecnológicas, Campus de Rio Parsanaíba, Rodovia BR 354 km 310, Cx. Postal 22, CEP, 38.810-000 Rio Paranaíba, MG (Brazil); Leroux, Fabrice; Dubois, Marc [Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6296, ICCF, BP 80026, F-6317 Clermont-Ferrand (France); Valim, João B. [Universidade de São Paulo, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Departamento de Química, Av. dos Bandeirantes 3900, CEP 14.040-901, Ribeirão Preto, SP (Brazil)

2015-01-15

A layered double hydroxide (LDH) with cation composition Zn{sub 2}Al was intercalated with 2-(thiophen-3-yl)acetate (3-TA) monomers. To achieve in situ polymerization and/or oligomerization of the intercalated monomers, soft thermal treatments were carried out, and subsequent hybrid LDH materials were analyzed by means of several characterization techniques using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), {sup 13}C CP–MAS nuclear magnetic resonance (NMR), electron spin resonance (EPR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), inductively coupled plasma optical emission spectroscopy (ICP–OES), and elemental analysis. PXRD analysis suggested that the intercalated monomers formed a bilayer. Thermal treatment of the hybrid LDH assembly above 120 °C provokes partially the breakdown of the layered structure, generating the phase zincite. EPR results indicated that vicinal monomers (oligomerization) were bound to each other after hydrothermal or thermal treatment, leading to a polaron response characteristic of electron conductivity localized on a restricted number of thiophene-based monomer segments. Localized unpaired electrons exist in the material and interact with the {sup 27}Al nuclei of the LDH layers by superhyperfine coupling. These unpaired electrons also interact with the surface of ZnO (O{sup 2−} vacancies), formed during the thermal treatments. - Graphical abstract: We synthesized a layered double hydroxide (LDH) with cation composition Zn{sub 2}Al, intercalated with 2-(thiophen-3-yl)acetate (3-TA) monomers, by coprecipitation at constant pH. We thermally treated the material, to achieve in situ polymerization and/or oligomerization of the intercalated monomers. - Highlights: • A Zn{sub 2}Al–LDH was intercalated with 2-(thiophen-3-yl)acetate monomers. • To achieve in situ oligomerization of the monomers, thermal treatments were made. �

Growth of Chlamydomonas reinhardtii in acetate-free medium when co-cultured with alginate-encapsulated, acetate-producing strains of Synechococcus sp. PCC 7002.

Science.gov (United States)

Therien, Jesse B; Zadvornyy, Oleg A; Posewitz, Matthew C; Bryant, Donald A; Peters, John W

2014-01-01

The model alga Chlamydomonas reinhardtii requires acetate as a co-substrate for optimal production of lipids, and the addition of acetate to culture media has practical and economic implications for algal biofuel production. Here we demonstrate the growth of C. reinhardtii on acetate provided by mutant strains of the cyanobacterium Synechococcus sp. PCC 7002. Optimal growth conditions for co-cultivation of C. reinhardtii with wild-type and mutant strains of Synechococcus sp. 7002 were established. In co-culture, acetate produced by a glycogen synthase knockout mutant of Synechococcus sp. PCC 7002 was able to support the growth of a lipid-accumulating mutant strain of C. reinhardtii defective in starch production. Encapsulation of Synechococcus sp. PCC 7002 using an alginate matrix was successfully employed in co-cultures to limit growth and maintain the stability. The ability of immobilized strains of the cyanobacterium Synechococcus sp. PCC 7002 to produce acetate at a level adequate to support the growth of lipid-accumulating strains of C. reinhartdii offers a potentially practical, photosynthetic alternative to providing exogenous acetate into growth media.

Esterification of phenyl acetic acid with p-cresol using metal cation exchanged montmorillonite nanoclay catalysts.

Science.gov (United States)

Bhaskar, M; Surekha, M; Suma, N

2018-02-01

The liquid phase esterification of phenyl acetic acid with p -cresol over different metal cation exchanged montmorillonite nanoclays yields p -cresyl phenyl acetate. Different metal cation exchanged montmorillonite nanoclays (M n +  = Al 3+ , Zn 2+ , Mn 2+ , Fe 3+ , Cu 2+ ) were prepared and the catalytic activity was studied. The esterification reaction was conducted by varying molar ratio of the reactants, reaction time and catalyst amount on the yield of the ester. Among the different metal cation exchanged catalysts used, Al 3+ -montmorillonite nanoclay was found to be more active. The characterization of the material used was studied under different techniques, namely X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The product obtained, p -cresyl phenyl acetate, was identified by thin-layer chromotography and confirmed by Fourier transform infrared, 1 H NMR and 13 C NMR. The regeneration activity of used catalyst was also investigated up to fourth generation.

Properties of Calcium Acetate Manufactured with Etching Waste Solution and Limestone Sludge as a Cementitious High-Early-Strength Admixture

OpenAIRE

Kim, Deuck-Mo; Ryu, Hwa-Sung; Shin, Sang-Heon; Park, Won-Jun

2016-01-01

Concrete is one of the most widely used construction materials. There are several methods available to improve its performance, with one of them being the use of high-early-strength admixtures (HESAs). Typical HESAs include calcium nitrate, calcium chloride, and calcium formate (CF). Industrial by-products, such as acetic acid and lime stone sludge (LSS), can be used together to produce calcium acetate (CA), which can subsequently be used as a cementitious HESA. In this study, calcium carbona...

Water/ice phase transition: The role of zirconium acetate, a compound with ice-shaping properties

Science.gov (United States)

Marcellini, Moreno; Fernandes, Francisco M.; Dedovets, Dmytro; Deville, Sylvain

2017-04-01

Few compounds feature ice-shaping properties. Zirconium acetate is one of the very few inorganic compounds reported so far to have ice-shaping properties similar to that of ice-shaping proteins, encountered in many organisms living at low temperature. When a zirconium acetate solution is frozen, oriented and perfectly hexagonal ice crystals can be formed and their growth follows the temperature gradient. To shed light on the water/ice phase transition while freezing zirconium acetate solution, we carried out differential scanning calorimetry measurements. From our results, we estimate how many water molecules do not freeze because of their interaction with Zr cations. We estimate the colligative properties of the Zr acetate on the apparent critical temperature. We further show that the phase transition is unaffected by the nature of the base which is used to adjust the pH. Our results provide thus new hints on the ice-shaping mechanism of zirconium acetate.

Heterotrophic utilization of acetate and glucose in Swartvlei, South Africa

International Nuclear Information System (INIS)

Robarts, R.D.

1979-01-01

The utilization of dissolved organic compounds in Swartvlei was measured by the addition of single concentrations of 14 C-labelled acetate and glucose to water samples. The results indicated acetate uptake was greatest in the aerobic zone while glucose was predominantly utilized in the anaerobic zone. With the exception of two months, integral glucose uptake was usually greater than the uptake of acetate. In August and September 1971 acetate was indicated as being utilized predominantly by flagellates and in December 1971 by dinoflagellates. During the remainder of the study, bacteria were assumed to be responsible for the uptake of acetate. The extensive weed beds which surround the upper reaches of Swartvlei may be a major source of acetate and glucose in the pelagic water column

Wax inhibitor based on ethylene vinyl acetate with methyl methacrylate and diethanolamine for crude oil pipeline

Science.gov (United States)

Anisuzzaman, S. M.; Abang, S.; Bono, A.; Krishnaiah, D.; Karali, R.; Safuan, M. K.

2017-06-01

Wax precipitation and deposition is one of the most significant flow assurance challenges in the production system of the crude oil. Wax inhibitors are developed as a preventive strategy to avoid an absolute wax deposition. Wax inhibitors are polymers which can be known as pour point depressants as they impede the wax crystals formation, growth, and deposition. In this study three formulations of wax inhibitors were prepared, ethylene vinyl acetate, ethylene vinyl acetate co-methyl methacrylate (EVA co-MMA) and ethylene vinyl acetate co-diethanolamine (EVA co-DEA) and the comparison of their efficiencies in terms of cloud point¸ pour point, performance inhibition efficiency (%PIE) and viscosity were evaluated. The cloud point and pour point for both EVA and EVA co-MMA were similar, 15°C and 10-5°C, respectively. Whereas, the cloud point and pour point for EVA co-DEA were better, 10°C and 10-5°C respectively. In conclusion, EVA co-DEA had shown the best % PIE (28.42%) which indicates highest percentage reduction of wax deposit as compared to the other two inhibitors.

Alternate fuels and chemicals from synthesis gas: Vinyl acetate monomer. Final report

Energy Technology Data Exchange (ETDEWEB)

Richard D. Colberg; Nick A. Collins; Edwin F. Holcombe; Gerald C. Tustin; Joseph R. Zoeller

1999-01-01

There has been a long-standing desire on the part of industry and the U.S. Department of Energy to replace the existing ethylene-based vinyl acetate monomer (VAM) process with an entirely synthesis gas-based process. Although there are a large number of process options for the conversion of synthesis gas to VAM, Eastman Chemical Company undertook an analytical approach, based on known chemical and economic principles, to reduce the potential candidate processes to a select group of eight processes. The critical technologies that would be required for these routes were: (1) the esterification of acetaldehyde (AcH) with ketene to generate VAM, (2) the hydrogenation of ketene to acetaldehyde, (3) the hydrogenation of acetic acid to acetaldehyde, and (4) the reductive carbonylation of methanol to acetaldehyde. This report describes the selection process for the candidate processes, the successful development of the key technologies, and the economic assessments for the preferred routes. In addition, improvements in the conversion of acetic anhydride and acetaldehyde to VAM are discussed. The conclusion from this study is that, with the technology developed in this study, VAM may be produced from synthesis gas, but the cost of production is about 15% higher than the conventional oxidative acetoxylation of ethylene, primarily due to higher capital associated with the synthesis gas-based processes.

Acetate causes alcohol hangover headache in rats.

Directory of Open Access Journals (Sweden)

Christina R Maxwell

2010-12-01

Full Text Available The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache.We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats.Ethanol initially decreased sensitivity to mechanical stimuli on the face (analgesia, followed 4 to 6 hours later by inflammatory pain. Inhibiting alcohol dehydrogenase extended the analgesia whereas inhibiting aldehyde dehydrogenase decreased analgesia. Neither treatment had nociceptive effects. Direct administration of acetate increased nociceptive behaviors suggesting that acetate, not acetaldehyde, accumulation results in hangover-like hypersensitivity in our model. Since adenosine accumulation is a result of acetate formation, we administered an adenosine antagonist that blocked hypersensitivity.Our study shows that acetate contributes to hangover headache. These findings provide insight into the mechanism of hangover headache and the mechanism of headache induction.

Homogeneity characterization of ethylene-co-vinyl acetate copolymer (EVA) and hydrophobic silica nanocomposite by low field NMR

International Nuclear Information System (INIS)

Stael, Giovanni Chaves; Tavares, Maria I.B.

2005-01-01

This project proposes the characterization of a polymeric matrix composite material using nanometric scale hydrophobic silica as charge element, with the ethylene-vinyl acetate (EVA), by using the spin-lattice relaxation time measurement applying the low field NMR

Addressing Cellulose Acetate Microfilm from a British Library perspective

Directory of Open Access Journals (Sweden)

Helen Shenton

2005-08-01

Full Text Available This paper is about cellulose acetate microfilm from the British Library perspective. It traces how acetate microfilm became an issue for the British Library and describes cellulose acetate deterioration. This is followed by details of what has already been done about the situation and what action is planned for the future.

Obestatin Accelerates the Healing of Acetic Acid-Induced Colitis in Rats

Directory of Open Access Journals (Sweden)

Aleksandra Matuszyk

2016-01-01

Full Text Available Obestatin, a 23-amino acid peptide derived from the proghrelin, has been shown to exhibit some protective and therapeutic effects in the gut. The aim of present study was to determine the effect of obestatin administration on the course of acetic acid-induced colitis in rats. Materials and Methods. Studies have been performed on male Wistar rats. Colitis was induced by a rectal enema with 3.5% acetic acid solution. Obestatin was administered intraperitoneally twice a day at a dose of 8 nmol/kg, starting 24 h after the induction of colitis. Seven or 14 days after the induction of colitis, the healing rate of the colon was evaluated. Results. Treatment with obestatin after induction of colitis accelerated the healing of colonic wall damage and this effect was associated with a decrease in the colitis-evoked increase in mucosal activity of myeloperoxidase and content of interleukin-1β. Moreover, obestatin administration significantly reversed the colitis-evoked decrease in mucosal blood flow and DNA synthesis. Conclusion. Administration of exogenous obestatin exhibits therapeutic effects in the course of acetic acid-induced colitis and this effect is related, at least in part, to the obestatin-evoked anti-inflammatory effect, an improvement of local blood flow, and an increase in cell proliferation in colonic mucosa.

Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge.

Science.gov (United States)

Ito, Tsukasa; Yoshiguchi, Kazumi; Ariesyady, Herto Dwi; Okabe, Satoshi

2011-12-01

Major acetate-utilizing bacterial and archaeal populations in methanogenic anaerobic digester sludge were identified and quantified by radioisotope- and stable-isotope-based functional analyses, microautoradiography-fluorescence in situ hybridization (MAR-FISH) and stable-isotope probing of 16S rRNA (RNA-SIP) that can directly link 16S rRNA phylogeny with in situ metabolic function. First, MAR-FISH with (14)C-acetate indicated the significant utilization of acetate by only two major groups, unidentified bacterial cells and Methanosaeta-like filamentous archaeal cells, in the digester sludge. To identify the acetate-utilizing unidentified bacteria, RNA-SIP was conducted with (13)C(6)-glucose and (13)C(3)-propionate as sole carbon source, which were followed by phylogenetic analysis of 16S rRNA. We found that bacteria belonging to Synergistes group 4 were commonly detected in both 16S rRNA clone libraries derived from the sludge incubated with (13)C-glucose and (13)C-propionate. To confirm that this bacterial group can utilize acetate, specific FISH probe targeting for Synergistes group 4 was newly designed and applied to the sludge incubated with (14)C-acetate for MAR-FISH. The MAR-FISH result showed that bacteria belonging to Synergistes group 4 significantly took up acetate and their active population size was comparable to that of Methanosaeta in this sludge. In addition, as bacteria belonging to Synergistes group 4 had high K(m) for acetate and maximum utilization rate, they are more competitive for acetate over Methanosaeta at high acetate concentrations (2.5-10  mM). To our knowledge, it is the first time to report the acetate-utilizing activity of uncultured bacteria belonging to Synergistes group 4 and its competitive significance to acetoclastic methanogen, Methanosaeta.

Vanadium based materials as electrode materials for high performance supercapacitors

Science.gov (United States)

Yan, Yan; Li, Bing; Guo, Wei; Pang, Huan; Xue, Huaiguo

2016-10-01

As a kind of supercapacitors, pseudocapacitors have attracted wide attention in recent years. The capacitance of the electrochemical capacitors based on pseudocapacitance arises mainly from redox reactions between electrolytes and active materials. These materials usually have several oxidation states for oxidation and reduction. Many research teams have focused on the development of an alternative material for electrochemical capacitors. Many transition metal oxides have been shown to be suitable as electrode materials of electrochemical capacitors. Among them, vanadium based materials are being developed for this purpose. Vanadium based materials are known as one of the best active materials for high power/energy density electrochemical capacitors due to its outstanding specific capacitance and long cycle life, high conductivity and good electrochemical reversibility. There are different kinds of synthetic methods such as sol-gel hydrothermal/solvothermal method, template method, electrospinning method, atomic layer deposition, and electrodeposition method that have been successfully applied to prepare vanadium based electrode materials. In our review, we give an overall summary and evaluation of the recent progress in the research of vanadium based materials for electrochemical capacitors that include synthesis methods, the electrochemical performances of the electrode materials and the devices.

Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

Directory of Open Access Journals (Sweden)

Xiao Li-guang

2016-01-01

Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

Identification of acetates in elasmopalpulus lignosellus pheromone glands using a newly created mass spectral database and kóvats retention indices

OpenAIRE

Jham, Gulab N.; Silva, Alexsandro A. da; Lima, Eraldo R.; Viana, Paulo A.

2007-01-01

Based on a specially created mass spectral database utilizing 23 tetradecenyl and 22 hexadecenyl acetate standards along with Kóvats retention indices obtained on a very polar stationary phase [poly (biscyanopropyl siloxane)] (SP 2340), (Z)-9-hexadecenyl acetate, (Z)-11-hexadecenyl acetate and (E)-8-hexadecenyl acetate were identified in active pheromone extracts of Elasmopalpus lignosellus. This identification was more efficient than our previous study using gas chromatography/mass spectrome...

Immobilization Patterns and Dynamics of Acetate-Utilizing Methanogens Immobilized in Sterile Granular Sludge in Upflow Anaerobic Sludge Blanket Reactors

Science.gov (United States)

Schmidt, Jens Ejbye; Ahring, Birgitte Kjær

1999-01-01

Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fed upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After several months of reactor operation, the methanogens were immobilized, either separately or together. The fastest immobilization was observed in the reactor containing M. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only M. mazeii S-6 immobilized, while the lowest effluent concentration of acetate was observed in the reactor where both types of methanogens were immobilized together. No changes were observed in the kinetic parameters (Ks and μmax) of immobilized M. concilii GP-6 or M. mazeii S-6 compared with suspended cultures, indicating that immobilization does not affect the growth kinetics of these methanogens. An enzyme-linked immunosorbent assay using polyclonal antibodies against either M. concilii GP-6 or M. mazeii S-6 showed significant variations in the two methanogenic populations in the different reactors. Polyclonal antibodies were further used to study the spatial distribution of the two methanogens. M. concilii GP-6 was immobilized only on existing support material without any specific pattern. M. mazeii S-6, however, showed a different immobilization pattern: large clumps were formed when the concentration of acetate was high, but where the acetate concentration was low this strain was immobilized on support material as single cells or small clumps. The data clearly show that the two aceticlastic methanogens immobilize differently in UASB systems, depending on the conditions found throughout the UASB reactor. PMID:10049862

Recovery of acetic acid from waste streams by extractive distillation.

Science.gov (United States)

Demiral, H; Yildirim, M Ercengiz

2003-01-01

Wastes have been considered to be a serious worldwide environmental problem in recent years. Because of increasing pollution, these wastes should be treated. However, industrial wastes can contain a number of valuable organic components. Recovery of these components is important economically. Using conventional distillation techniques, the separation of acetic acid and water is both impractical and uneconomical, because it often requires large number of trays and a high reflux ratio. In practice special techniques are used depending on the concentration of acetic acid. Between 30 and 70% (w/w) acetic acid contents, extractive distillation was suggested. Extractive distillation is a multicomponent-rectification method similar in purpose to azeotropic distillation. In extractive distillation, to a binary mixture which is difficult or impossible to separate by ordinary means, a third component termed an entrainer is added which alters the relative volatility of the original constituents, thus permitting the separation. In our department acetic acid is used as a solvent during the obtaining of cobalt(III) acetate from cobalt(II) acetate by an electrochemical method. After the operation, the remaining waste contains acetic acid. In thiswork, acetic acid which has been found in this waste was recovered by extractive distillation. Adiponitrile and sulfolane were used as high boiling solvents and the effects of solvent feed rate/solution feed rate ratio and type were investigated. According to the experimental results, it was seem that the recovery of acetic acid from waste streams is possible by extractive distillation.

RIFM fragrance ingredient safety assessment, acetic acid, C7-9-branched alkyl esters, C8-rich, CAS Registry Number 108419-32-5.

Science.gov (United States)

Api, A M; Belsito, D; Botelho, D; Browne, D; Bruze, M; Burton, G A; Buschmann, J; Calow, P; Dagli, M L; Date, M; Dekant, W; Deodhar, C; Fryer, A D; Joshi, K; La Cava, S; Lapczynski, A; Liebler, D C; O'Brien, D; Parakhia, R; Patel, A; Penning, T M; Ritacco, G; Romine, J; Salvito, D; Schultz, T W; Sipes, I G; Thakkar, Y; Tsang, S; Wahler, J

2017-12-01

The use of this material under current conditions is supported by existing information. This material was evaluated for genotoxicity, repeated dose toxicity, developmental and reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, as well as environmental safety. Data show that this material is not genotoxic. Data from the suitable read across analog isoamyl acetate (CAS# 123-92-2) show that this material does not have skin sensitization potential. The reproductive and local respiratory toxicity endpoints were completed using the TTC (Threshold of Toxicological Concern) for a Cramer Class I material (0.03 mg/kg/day and 1.4 mg/day, respectively). The repeated dose and developmental endpoint was completed using data on the target material, which provided a MOE > 100. The phototoxicity/photoallergenicity endpoint was completed based on suitable UV spectra. The environmental endpoint was completed as described in the RIFM Framework. Copyright © 2017 Elsevier Ltd. All rights reserved.

Disorder effects in Mn(12)-acetate at 83 K.

Science.gov (United States)

Cornia, Andrea; Fabretti, Antonio Costantino; Sessoli, Roberta; Sorace, Lorenzo; Gatteschi, Dante; Barra, Anne-Laure; Daiguebonne, Carole; Roisnel, Thierry

2002-07-01

The structure of hexadeca-mu-acetato-tetraaquadodeca-mu(3)-oxo-dodecamanganese bis(acetic acid) tetrahydrate, [Mn(12)O(12)(CH(3)COO)(16)(H(2)O)(4)] x 2CH(3)COOH x 4H(2)O, known as Mn(12)-acetate, has been determined at 83 (2) K by X-ray diffraction methods. The fourfold (S(4)) molecular symmetry is disrupted by a strong hydrogen-bonding interaction with the disordered acetic acid molecule of solvation, which displaces one of the acetate ligands in the cluster. Up to six Mn(12) isomers are potentially present in the crystal lattice, which differ in the number and arrangement of hydrogen-bonded acetic acid molecules. These results considerably improve the structural information available on this molecular nanomagnet, which was first synthesized and characterized by Lis [Acta Cryst. (1980), B36, 2042-2046].

Effect of lead acetate on follicular count of mice ovary and the protective role of garlic extract

International Nuclear Information System (INIS)

Waseem, N.; Hamid, S.; Butt, S.A.

2014-01-01

Objective: The study was conducted to evaluate the effects of lead acetate and protective role of garlic extract on the histomorphology of the ovarian follicles in an animal model. Study Design: Laboratory based randomized control trial Place and Duration of Study: Department of Anatomy, Army Medical College in collaboration with National Institute of Health from April-June 2013 Material and Methods: Thirty female BALBc mice were selected. Mice were randomly divided into three groups. 10 animals were placed in each group. Group A being the control was given normal diet. Group B was given lead acetate at a dose of 30 mg/kg/day. Group C was given lead acetate 30mg/kg/day and garlic extract 500 mg/kg/day through oral lavage tube for 60 days. Animals were sacrificed and dissected at the end of 60th day. Length and width of the ovary were measured, right ovary was processed, embedded and stained for histological study. Primary, secondary and graafian follicles were counted and noted. Results: There was reduction in the number of primary and graafian follicles in group B when compared to group A. In group C there was relatively increase in number of follicles, when compared to group B. Number of secondary follicles was almost same in all the groups. The length of ovary was higher in group A as compared to group B. In group C results were same as group A regarding length of the ovary. Width of ovary was same between the respective groups. Conclusion: The follicular count was markedly affected in lead acetate treated group which improved when co treated with garlic extract in experimental group C. Hence, garlic had a protective role against lead induced changes in mice ovary. (author)

Evaluation of ECG-gated [(11)C]acetate PET for measuring left ventricular volumes, mass, and myocardial external efficiency.

Science.gov (United States)

Hansson, Nils Henrik; Tolbod, Lars; Harms, Johannes; Wiggers, Henrik; Kim, Won Yong; Hansen, Esben; Zaremba, Tomas; Frøkiær, Jørgen; Jakobsen, Steen; Sørensen, Jens

2016-08-01

Noninvasive estimation of myocardial external efficiency (MEE) requires measurements of left ventricular (LV) oxygen consumption with [(11)C]acetate PET in addition to LV stroke volume and mass with cardiovascular magnetic resonance (CMR). Measuring LV geometry directly from ECG-gated [(11)C]acetate PET might enable MEE evaluation from a single PET scan. Therefore, we sought to establish the accuracy of measuring LV volumes, mass, and MEE directly from ECG-gated [(11)C]acetate PET. Thirty-five subjects with aortic valve stenosis underwent ECG-gated [(11)C]acetate PET and CMR. List mode PET data were rebinned into 16-bin ECG-gated uptake images before measuring LV volumes and mass using commercial software and compared to CMR. Dynamic datasets were used for calculation of mean LV oxygen consumption and MEE. LV mass, volumes, and ejection fraction measured by CMR and PET correlated strongly (r = 0.86-0.92, P PET (P PET-based MEE, corrected for bias, correlated fairly with PET/CMR-based MEE (r = 0.60, P PET-based MEE bias was strongly associated with LV wall thickness. Although analysis-related improvements in accuracy are recommended, LV geometry estimated from ECG-gated [(11)C]acetate PET correlate excellently with CMR and can indeed be used to evaluate MEE.

Density, refraction index and vapor–liquid equilibria of N-methyl-2-hydroxyethylammonium butyrate plus (methyl acetate or ethyl acetate or propyl acetate) at several temperatures

International Nuclear Information System (INIS)

Alvarez, V.H.; Mattedi, S.; Aznar, M.

2013-01-01

Highlights: ► Densities, refraction indices and VLE were measured for ester + m-2-HEAB mixtures. ► V E , apparent molar volumes and thermal expansion coefficients were calculated. ► Peng–Robinson EoS + Wong–Sandler mixing rule + COSMO-SAC predicted the data. -- Abstract: This paper reports the densities, refraction indices, and vapor liquid equilibria for binary systems ester + N-methyl-2-hydroxyethylammonium butyrate (m-2-HEAB): methyl acetate (1) + m-2-HEAB (2), ethyl acetate (1) + m-2-HEAB and propyl acetate (1) + m-2-HEAB (2). The excess molar volumes, deviations in the refraction index, apparent molar volumes, and thermal expansion coefficients for the binary systems were fitted to polynomial equations. The Peng–Robinson equation of state, coupled with the Wong–Sandler mixing rule, is used to describe the experimental data. Since the predictive activity coefficient model COSMO-SAC is used in the Wong–Sandler mixing rule, the resulting thermodynamic model is a completely predictive one. The prediction results for the density and for the vapor–liquid equilibria have a deviation lower than 1.0% and 1.1%, respectively

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

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false 5-Hydroxyindole acetic acid/serotonin test system... Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A 5-hydroxyindole acetic acid/serotonin test system is a device intended to measure 5-hydroxyindole acetic acid...

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Dried Musa paradiciaca (banana) stem and veins of the leaves, which were hitherto discarded as a waste, were collected and used as starting material for the preparation of cellulose and cellulose acetate. This cellulose acetate was mixed with polystyrene to form blend of cellulose acetate–polystyrene in order to provide ...

Immobilization patterns and dynamics of acetate-utilizing methanogens in sterile granular sludge from upflow anaerobic sludge blanket (UASB) reactors

DEFF Research Database (Denmark)

Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

1999-01-01

Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fea upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After......, but where the acetate concentration was low this strain was immobilized on support material as single cells or small clumps, The data clearly show that the two aceticlastic methanogens immobilize differently in UASB systems, depending on the conditions found throughout the UASB reactor....

Immobilization patterns and dynamics of acetate-utilizing methanogens immobilized in sterile granular sludge in upflow anaerobic sludge blanket reactors

DEFF Research Database (Denmark)

Schmidt, Jens Ejbye; Ahring, Birgitte Kiær

1999-01-01

Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fea upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After......, but where the acetate concentration was low this strain was immobilized on support material as single cells or small clumps, The data clearly show that the two aceticlastic methanogens immobilize differently in UASB systems, depending on the conditions found throughout the UASB reactor....

A novel multifunctional biomedical material based on polyacrylonitrile: Preparation and characterization

Energy Technology Data Exchange (ETDEWEB)

Wu, Huan-ling [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Jiuzhou College of Pharmacy, Yancheng Institute of Industry Technology, Yancheng 224005 (China); Bremner, David H. [School of Science, Engineering and Technology, Kydd Building, Abertay University, Dundee DD1 1HG, Scotland (United Kingdom); Li, He-yu; Shi, Qi-quan; Wu, Jun-zi; Xiao, Rui-qiu [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Zhu, Li-min, E-mail: lzhu@dhu.edu.cn [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China)

2016-05-01

Wet spun microfibers have great potential in the design of multifunctional controlled release materials. Curcumin (Cur) and vitamin E acetate (Vit. E Ac) were used as a model drug system to evaluate the potential application of the drug-loaded microfiber system for enhanced delivery. The drugs and polyacrylonitrile (PAN) were blended together and spun to produce the target drug-loaded microfiber using an improved wet-spinning method and then the microfibers were successfully woven into fabrics. Morphological, mechanical properties, thermal behavior, drug release performance characteristics, and cytocompatibility were determined. The drug-loaded microfiber had a lobed “kidney” shape with a height of 50–100 μm and width of 100–200 μm. The addition of Cur and Vit. E Ac had a great influence on the surface and cross section structure of the microfiber, leading to a rough surface having microvoids. X-ray diffraction and Fourier transform infrared spectroscopy indicated that the drugs were successfully encapsulated and dispersed evenly in the microfilament fiber. After drug loading, the mechanical performance of the microfilament changed, with the breaking strength improved slightly, but the tensile elongation increased significantly. Thermogravimetric results showed that the drug load had no apparent adverse effect on the thermal properties of the microfibers. However, drug release from the fiber, as determined through in-vitro experiments, is relatively low and this property is maintained over time. Furthermore, in-vitro cytocompatibility testing showed that no cytotoxicity on the L929 cells was found up to 5% and 10% respectively of the theoretical drug loading content (TDLC) of curcumin and vitamin E acetate. This study provides reference data to aid the development of multifunctional textiles and to explore their use in the biomedical material field. - Highlights: • Based on a wet spinning technique, a series of filaments which can be used as biomaterial

A novel multifunctional biomedical material based on polyacrylonitrile: Preparation and characterization

International Nuclear Information System (INIS)

Wu, Huan-ling; Bremner, David H.; Li, He-yu; Shi, Qi-quan; Wu, Jun-zi; Xiao, Rui-qiu; Zhu, Li-min

2016-01-01

Wet spun microfibers have great potential in the design of multifunctional controlled release materials. Curcumin (Cur) and vitamin E acetate (Vit. E Ac) were used as a model drug system to evaluate the potential application of the drug-loaded microfiber system for enhanced delivery. The drugs and polyacrylonitrile (PAN) were blended together and spun to produce the target drug-loaded microfiber using an improved wet-spinning method and then the microfibers were successfully woven into fabrics. Morphological, mechanical properties, thermal behavior, drug release performance characteristics, and cytocompatibility were determined. The drug-loaded microfiber had a lobed “kidney” shape with a height of 50–100 μm and width of 100–200 μm. The addition of Cur and Vit. E Ac had a great influence on the surface and cross section structure of the microfiber, leading to a rough surface having microvoids. X-ray diffraction and Fourier transform infrared spectroscopy indicated that the drugs were successfully encapsulated and dispersed evenly in the microfilament fiber. After drug loading, the mechanical performance of the microfilament changed, with the breaking strength improved slightly, but the tensile elongation increased significantly. Thermogravimetric results showed that the drug load had no apparent adverse effect on the thermal properties of the microfibers. However, drug release from the fiber, as determined through in-vitro experiments, is relatively low and this property is maintained over time. Furthermore, in-vitro cytocompatibility testing showed that no cytotoxicity on the L929 cells was found up to 5% and 10% respectively of the theoretical drug loading content (TDLC) of curcumin and vitamin E acetate. This study provides reference data to aid the development of multifunctional textiles and to explore their use in the biomedical material field. - Highlights: • Based on a wet spinning technique, a series of filaments which can be used as biomaterial

Acetate adaptation of clostridia tyrobutyricum for improved fermentation production of butyrate.

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Jaros, Adam M; Rova, Ulrika; Berglund, Kris A

2013-12-01

Clostridium tyrobutyricum ATCC 25755 is an acidogenic bacterium capable of utilizing xylose for the fermentation production of butyrate. Hot water extraction of hardwood lingocellulose is an efficient method of producing xylose where autohydrolysis of xylan is catalysed by acetate originating from acetyl groups present in hemicellulose. The presence of acetic acid in the hydrolysate might have a severe impact on the subsequent fermentations. In this study the fermentation kinetics of C. tyrobutyricum cultures after being classically adapted for growth at 26.3 g/L acetate equivalents were studied. Analysis of xylose batch fermentations found that even in the presence of high levels of acetate, acetate adapted strains had similar fermentation kinetics as the parental strain cultivated without acetate. The parental strain exposed to acetate at inhibitory conditions demonstrated a pronounced lag phase (over 100 hours) in growth and butyrate production as compared to the adapted strain (25 hour lag) or non-inhibited controls (0 lag). Additional insight into the metabolic pathway of xylose consumption was gained by determining the specific activity of the acetate kinase (AK) enzyme in adapted versus control batches. AK activity was reduced by 63% in the presence of inhibitory levels of acetate, whether or not the culture had been adapted.

Identification of acetates in elasmopalpulus lignosellus pheromone glands using a newly created mass spectral database and kóvats retention indices

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Gulab N. Jham

2007-08-01

Full Text Available Based on a specially created mass spectral database utilizing 23 tetradecenyl and 22 hexadecenyl acetate standards along with Kóvats retention indices obtained on a very polar stationary phase [poly (biscyanopropyl siloxane] (SP 2340, (Z-9-hexadecenyl acetate, (Z-11-hexadecenyl acetate and (E-8-hexadecenyl acetate were identified in active pheromone extracts of Elasmopalpus lignosellus. This identification was more efficient than our previous study using gas chromatography/mass spectrometry with a dimethyl disulfide derivative where we could only identify the first two acetates. The acetate composition of the pheromone gland differed from region to region in Brazil and from that from the Tifton (GA, USA population, suggesting polymorphism or a different sub-species.

The Key to Acetate: Metabolic Fluxes of Acetic Acid Bacteria under Cocoa Pulp Fermentation-Simulating Conditions

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Adler, Philipp; Frey, Lasse Jannis; Berger, Antje; Bolten, Christoph Josef; Hansen, Carl Erik

2014-01-01

Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel 13C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present. PMID:24837393

Analysis of Mechanical and Thermogravimetric Properties of Composite Materials Based on PVA/MWCNT and Styrene-Acrylic Copolymer/MWCNT

Science.gov (United States)

Volynets, N. I.; Poddubskaya, O. G.; Demidenko, M. I.; Lyubimov, A. G.; Kuzhir, P. P.; Suslyaev, V. I.; Pletnev, M. A.; Zicans, Janis

2017-08-01

Mechanical and thermogravimetric properties of polymer composite materials with various concentrations of multiwalled carbon nanotubes effectively shielding radiation in the radio frequency (20 Hz - 1 MHz) and microwave (26-36 GHz) frequency ranges are studied. As a matrix, widely available polymeric materials, such as polyvinyl acetate and styrene-acrylate, were used in the form of dispersions. From the analysis of the obtained experimental data, it was shown that the introduction of carbon nanotubes into the polymer matrix makes it possible to increase mechanical properties and thermal stability of composite materials.

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

International Nuclear Information System (INIS)

Tao, Y.; Cao, X.; Peng, Y.; Liu, Y.; Zhang, R.

2012-01-01

We report on a cataluminescence sensor for the determination of gaseous acetic acid. It is based on a 60-nm thick sol-gel film of In 2 O 3 on a ceramic support. SEM, XPS and surface profiling were applied for its characterization. It is found that aluminum ions of the ceramic substrate penetrate into the film and produce a synergetic catalytic effect. The sensor displays high sensitivity and specificity for acetic acid, a low detection limit, a wide linear range and a fast response. No (or only very low) interference was observed by formic acid, ammonia, acrolein, benzene, formaldehyde, ethanol, and acetaldehyde. The sensor was successfully applied to the determination of acetic acid in spiked air samples. We also discuss a conceivable mechanism (based on the reaction products) for the cataluminescence resulting from the oxidation reaction on the surface of the sensor film. (author)

Radiation sterilization of hydrocortisone acetate

International Nuclear Information System (INIS)

Charef, A.; Boussaha, A.

1989-09-01

The feasibility of using high energy ionizing radiation for the sterilization of hydrocortisone acetate was investigated. Hydrocortisone acetate in the form of powder was exposed to different dose levels of gamma radiation using a Cobalt-60 source. The irradiated samples were examined by various physico-chemical techniques in order to detect possible radiolysis products. It was of interest to know if one could insure sterility and retain biological properties of the drug by suitable choice of radiation dose. The results showed that a 10 KGy radiation dose causes no change in the physico-chemical properties of the drug and is sufficient to obtain contaminant-free product

Development of a green supercapacitor composed entirely of environmentally friendly materials.

Science.gov (United States)

Dyatkin, Boris; Presser, Volker; Heon, Min; Lukatskaya, Maria R; Beidaghi, Majid; Gogotsi, Yury

2013-12-01

Owing to recent power- and energy-density advances, higher efficiencies, and almost unlimited lifetimes, electrical double-layer capacitors (EDLCs, also known as supercapacitors) are now used in a wide range of energy harvesting and storage systems, which include portable power and grid applications. Despite offering key performance advantages, many device components pose significant environmental hazards once disposed. They often contain fluorine, sulfur, and cyanide groups, which are harmful if discarded by using conventional landfill or incineration methods, and they are constructed by using multiple metallic parts, which contribute to a high ash content. We explore designs for a fully operational supercapacitor that incorporates materials completely safe to dispose of and easy to incinerate. The components, which include material alternatives for the current collector, electrolyte, separator, particle binder, and packaging, are all mutually compatible, and most of them exhibit better performance than commonly used materials. We selected a graphite foil as current collector, sodium acetate as electrolyte, an ester as porous membrane based on acetate cellulose, and polymers based on polyvinyl alcohol as environmentally benign solutions for device components. The presented materials all originate from simple and inexpensive source compounds, which decreases the environmental impact of their manufacture and renders them more viable for integration into commercial devices for large-scale stationary and transportation energy storage applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Materials And Processes Technical Information System (MAPTIS) LDEF materials data base

Science.gov (United States)

Funk, Joan G.; Strickland, John W.; Davis, John M.

1993-01-01

A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated from LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux) and author(s) or principal investigator(s). Tne LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which has been computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. The LDEF Materials Data Base is described and step-by-step example searches using the data base are included. Information on how to become an authorized user of the system is included.

Ultrasonic cleaning of conveyor belt materials using Listeria monocytogenes as a model organism.

Science.gov (United States)

Tolvanén, Riina; Lunden, Janne; Korkeala, Hannu; Wirtanen, Gun

2007-03-01

Persistent Listeria monocytogenes contamination of food industry equipment is a difficult problem to solve. Ultrasonic cleaning offers new possibilities for cleaning conveyors and other equipment that are not easy to clean. Ultrasonic cleaning was tested on three conveyor belt materials: polypropylene, acetal, and stainless steel (cold-rolled, AISI 304). Cleaning efficiency was tested at two temperatures (30 and 45 degrees C) and two cleaning times (30 and 60 s) with two cleaning detergents (KOH, and NaOH combined with KOH). Conveyor belt materials were soiled with milk-based soil and L. monocytogenes strains V1, V3, and B9, and then incubated for 72 h to attach bacteria to surfaces. Ultrasonic cleaning treatments reduced L. monocytogenes counts on stainless steel 4.61 to 5.90 log units; on acetal, 3.37 to 5.55 log units; and on polypropylene, 2.31 to 4.40 log units. The logarithmic reduction differences were statistically analyzed by analysis of variance using Statistical Package for the Social Sciences software. The logarithmic reduction was significantly greater in stainless steel than in plastic materials (P conveyor belt materials.

Different characteristic effects of ageing on starch-based films plasticised by 1-ethyl-3-methylimidazolium acetate and by glycerol.

Science.gov (United States)

Zhang, Binjia; Xie, Fengwei; Zhang, Tianlong; Chen, Ling; Li, Xiaoxi; Truss, Rowan W; Halley, Peter J; Shamshina, Julia L; McNally, Tony; Rogers, Robin D

2016-08-01

The focus of this study was on the effects of plasticisers (the ionic liquid 1-ethyl-3-methylimidazolium acetate, or [Emim][OAc]; and glycerol) on the changes of starch structure on multiple length scales, and the variation in properties of plasticised starch-based films, during ageing. The films were prepared by a simple melt compression moulding process, followed by storage at different relative humidity (RH) environments. Compared with glycerol, [Emim][OAc] could result in greater homogeneity in [Emim][OAc]-plasticised starch-based films (no gel-like aggregates and less molecular order (crystallites) on the nano-scale). Besides, much weaker starch-starch interactions but stronger starch-[Emim][OAc] interactions at the molecular level led to reduced strength and stiffness but increased flexibility of the films. More importantly, [Emim][OAc] (especially at high content) was revealed to more effectively maintain the plasticised state during ageing than glycerol: the densification (especially in the amorphous regions) was suppressed; and the structural characteristics especially on the nano-scale were stabilised (especially at a high RH), presumably due to the suppressed starch molecular interactions by [Emim][OAc] as confirmed by Raman spectroscopy. Such behaviour contributed to stabilised mechanical properties. Nonetheless, the crystallinity and thermal stability of starch-based films with both plasticisers were much less affected by ageing and moisture uptake during storage (42 days), but mostly depended on the plasticiser type and content. As starch is a typical semi-crystalline bio-polymer containing abundant hydroxyl groups and strong hydrogen bonding, the findings here could also be significant in creating materials from other similar biopolymers with tailored sensitivity and properties to the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

The method of quantitative determination of iodine in acetic acid

International Nuclear Information System (INIS)

Sukhomlinov, A.B.; Kalinchenko, N.B.

1988-01-01

Method for separate determination of J 2 and J - concentrations in acetic acid is suggested. Iodine concentration in acetic acid is determined by measuring potential of iodine-selective electrode first in the initial solution of acetic acid, where molecular iodine dissociation equals 0.5, and then in acetic acid, with alkali (NaOH) addition up to pH > 3, where molecular iodine dissociation equals 1. Determination is conducted in 5x10 -7 -5x10 -6 mol/l concentration range with relative standard deviation not more than 0.1. 1 fig

Investigation of size effect on film type haptic actuator made with cellulose acetate

International Nuclear Information System (INIS)

Kim, Sang-Youn; Kim, Jaehwan; Kim, Ki-Baek

2014-01-01

The most important factor in haptic interaction with hand-held devices is to develop a thin film type actuator which can be easily inserted into the devices and create vibrotactile signals with wide frequency bandwidth. This paper reports a film type vibrotactile actuator which is tiny enough to be embedded into small hand-held devices. The vibration mechanism and experiment results for the suggested vibrotactile actuator are explained. The aim of the actuator is to convey a vibrotactile force greater than a human’s vibrotactile threshold with broad frequency bandwidth to users. To achieve the requirement, we fabricate a film type vibrotactile actuator with cellulose acetate. When an AC voltage is applied to the actuator, the cellulose acetate film gets charged and then generates vibration. The suggested vibrotactile actuator is fabricated in two sizes: 50 mm × 25 mm and 25 mm × 25 mm. For each size of actuator, three kinds of actuator are fabricated with different pillar materials to support the cellulose acetate films. An experiment for measuring vibrational amplitude is conducted over a wide frequency range of actuation voltage. It is known that the proposed film type actuator is feasible for haptic application in the small hand-held devices. (paper)

High Acetic Acid Production Rate Obtained by Microbial Electrosynthesis from Carbon Dioxide.

Science.gov (United States)

Jourdin, Ludovic; Grieger, Timothy; Monetti, Juliette; Flexer, Victoria; Freguia, Stefano; Lu, Yang; Chen, Jun; Romano, Mark; Wallace, Gordon G; Keller, Jurg

2015-11-17

High product specificity and production rate are regarded as key success parameters for large-scale applicability of a (bio)chemical reaction technology. Here, we report a significant performance enhancement in acetate formation from CO2, reaching comparable productivity levels as in industrial fermentation processes (volumetric production rate and product yield). A biocathode current density of -102 ± 1 A m(-2) and an acetic acid production rate of 685 ± 30 (g m(-2) day(-1)) have been achieved in this study. High recoveries of 94 ± 2% of the CO2 supplied as the sole carbon source and 100 ± 4% of electrons into the final product (acetic acid) were achieved after development of a mature biofilm, reaching an elevated product titer of up to 11 g L(-1). This high product specificity is remarkable for mixed microbial cultures, which would make the product downstream processing easier and the technology more attractive. This performance enhancement was enabled through the combination of a well-acclimatized and enriched microbial culture (very fast start-up after culture transfer), coupled with the use of a newly synthesized electrode material, EPD-3D. The throwing power of the electrophoretic deposition technique, a method suitable for large-scale production, was harnessed to form multiwalled carbon nanotube coatings onto reticulated vitreous carbon to generate a hierarchical porous structure.

21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate-vinyl alcohol copolymers... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1360 Ethylene-vinyl acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2...

The Cost-Effectiveness of Emergency Hormonal Contraception with Ulipristal Acetate versus Levonorgestrel for Minors in France.

Directory of Open Access Journals (Sweden)

Ramona Schmid

Full Text Available To evaluate the cost-effectiveness of ulipristal acetate and levonorgestrel in minors in France, and analyze whether it is worthwhile to provide ulipristal acetate to minors free of charge.The cost-effectiveness of two emergency contraceptive methods was compared based on a decision-analytical model. Pregnancy rates, outcomes of unintended pregnancies, and resource utilization were derived from the literature. Resources and their costs were considered until termination or a few days after delivery. Deterministic and probabilistic sensitivity analyses were performed.The cost of an unintended pregnancy in a French minor is estimated to be 1,630 € (range 1,330 € - 1,803 €. Almost 4 million € (3.1 € - 13.7 € million in unintended pregnancy spending in 2010 could have been saved by the use of ulipristal acetate instead of levonorgestrel. The incremental cost of ulipristal acetate compared to levonorgestrel is 3.30 € per intake, or 418 € per pregnancy avoided (intake within 72 hours. In the intake within 24 hours subgroup, ulipristal acetate was found to be more efficacious at a lower cost compared to levonorgestrel.Ulipristal acetate dominates levonorgestrel when taken within 24 hours after unprotected intercourse, i.e., it is more effective at a lower cost. When taken within 72 hours, ulipristal acetate is a cost- effective alternative to levonorgestrel, given that the cost of avoiding an additional pregnancy with ulipristal acetate is less than the average cost of these pregnancies. In the light of these findings, it is worthwhile to provide free access to minors.

Precious-metal-base advanced materials

International Nuclear Information System (INIS)

Nowicki, T.; Carbonnaux, C.

1993-01-01

Precious metals constitute also the base of several advanced materials used in the industry in hundreds of metric tons. Platinum alloys have been used as structural materials for equipments in the glass industry. The essential reason for this is the excellent resistance of platinum alloys to oxidation and electrolytical corrosion in molten glasses at temperatures as high as 1200-1500 C. The major drawback is a weak creep resistance. The unique way for significant improvement of platinum base materials creep resistance is a strengthening by an oxide dispersion (ODS). In the case of CLAL's patented ''Plativer'' materials, 0.05 wt% of Y 2 O 3 is incorporated within the alloy matrix by the flame spraying process. Further improvement of platinum base materials is related, in the authors opinion, to the development of precious metals base intermetallics. Another interesting applications of precious metals are silver base electrical contacts. They are in fact silver matrix composites containing varying amounts of well-dispersed particles of constituents such as CdO, SnO 2 , Ni, WC or C. In the case of such materials, particular properties are required and tested : resistance to arc erosion, resistance to welding and contact resistance. Many other technically fascinating precious metals base materials exist: brazing alloys for assembling metals, superconductors and ceramics; dental materials including magnetic biocompatible alloys; silver composites for superconductor wire jackets. The observation of current evolution indicates very clearly that precious metals cannot be replaced by common metals because of their unique characteristics due to their atomic level properties

Characterization of acetate transport in colorectal cancer cells and potential therapeutic implications

Science.gov (United States)

Ferro, Suellen; Azevedo-Silva, João; Casal, Margarida; Côrte-Real, Manuela; Baltazar, Fatima; Preto, Ana

2016-01-01

Acetate, together with other short chain fatty acids has been implicated in colorectal cancer (CRC) prevention/therapy. Acetate was shown to induce apoptosis in CRC cells. The precise mechanism underlying acetate transport across CRC cells membrane, that may be implicated in its selectivity towards CRC cells, is not fully understood and was addressed here. We also assessed the effect of acetate in CRC glycolytic metabolism and explored its use in combination with the glycolytic inhibitor 3-bromopyruvate (3BP). We provide evidence that acetate enters CRC cells by the secondary active transporters MCT1 and/or MCT2 and SMCT1 as well as by facilitated diffusion via aquaporins. CRC cell exposure to acetate upregulates the expression of MCT1, MCT4 and CD147, while promoting MCT1 plasma membrane localization. We also observed that acetate increases CRC cell glycolytic phenotype and that acetate-induced apoptosis and anti-proliferative effect was potentiated by 3BP. Our data suggest that acetate selectivity towards CRC cells might be explained by the fact that aquaporins and MCTs are found overexpressed in CRC clinical cases. Our work highlights the importance that acetate transport regulation has in the use of drugs such as 3BP as a new therapeutic strategy for CRC. PMID:28874966

Vacuum FTIR study on the hygroscopicity of magnesium acetate aerosols

Science.gov (United States)

Wang, Na; Cai, Chen; He, Xiang; Pang, Shu-Feng; Zhang, Yun-Hong

2018-03-01

Hygroscopicity and volatility of secondary organic aerosol (SOA) are two important properties, which determine the composition, concentration, size, phase state of SOA and thus chemical and optical properties for SOA. In this work, magnesium acetate (Mg(Ac)2) aerosol was used as a simple SOA model in order to reveal relationship between hygroscopicity and volatility. A novel approach was set up based on a combination of a vacuum FTIR spectrometer and a home-made relative humidity (RH) controlling system. The striking advantage of this approach was that the RH and the compositions of aerosols could be obtained from a same IR spectrum, which guaranteed the synchronism between RH and spectral features on a sub-second scale. At the constant RH of 90% and 80% for 3000 s, the water content within Mg(Ac)2 aerosol particles decreased about 19.0% and 9.4% while there were 13.4% and 6.0% of acetate loss. This was attributed to a cooperation between volatile of acetic acid and Mg2 + hydrolysis in Mg(Ac)2 aerosols, which greatly suppressed the hygroscopicity of Mg(Ac)2 aerosols. When the RH changed with pulsed mode between 70% and 90%, hygroscopicity relaxation was observed for Mg(Ac)2 aerosols. Diffuse coefficient of water in the relaxation process was estimated to be 5 × 10- 12 m2·s- 1 for the Mg(Ac)2 aerosols. Combining the IR spectra analysis, the decrease in the diffuse coefficient of water was due to the formation of magnesium hydroxide accompanying acetic acid evaporation in the aerosols.

Performance of magnetorheological elastomer based green epoxidized natural rubber/sucrose acetate isobutyrate hybrid matrix

Science.gov (United States)

Khairi, Muntaz Hana Ahmad; Amri Mazlan, Saiful; Aziz, Siti Aishah Abdul; Ubaidillah; Tan Shilan, Salihah

2018-04-01

This study introduces a sucrose acetate isobutyrate (SAIB) as a novel additive of magnetorheological elastomers (MREs). The MREs utilized an epoxidized natural rubber (ENR) as the matrix and carbonyl iron particles (CIPs) as their filler. The CIPs were fixed at 60 wt%. The viscosity of the compound was observed using a viscometer. Meanwhile, the microstructures were observed by using field emission scanning electron microscope (FESEM). Rheological properties regarding shear storage modulus were measured by using a rheometer (MCR 302, Anton Paar). The experimental results demonstrated that the MREs-based ENR/SAIB had a decrement in their viscosity by 40% reduction. Moreover, the magnetorheological (MR) effect increased by 23% as the increment of magnetic fields. The morphological photograph showed that the CIPs embedded well within the matrix. The fabricated MREs samples were strain dependent, where all MREs samples exhibit the deteriorating trend when increasing the strain amplitude.

Synthesis and physical-chemical properties of 3-benzyl-8-propylxanthinyl-7-acetic acid and its derivatives

Directory of Open Access Journals (Sweden)

E. K. Mikhalchenko

2017-04-01

Full Text Available Introduction. Heterocyclic compounds play an important role in the metabolic processes of human organism. Structures of vitamins, nucleotides, chromoproteins are based on Nitrogen-containing heterocycles (purine, pyrimidine, thiazole etc. Thus, it was obvious to use these organic substances as basic molecules for synthetic research of biologically active compounds which could be used for treatment of different pathological processes. In their research, some scientist pay special attention to xanthine derivatives that are well-known low toxic natural compounds with wide spectrum of pronounced pharmacological properties (antioxidant, diuretic, antibacterial, anti-inflammatory etc. Insertion of carboxyl group in the structure of xanthine molecule is a prospective ability of its synthetic potential increasing. Aim of our research was the development of method of 3-benzyl-8-propylxanthinyl-7-acetic acid and its derivatives synthesis and studying their physical-chemical properties. Materials and methods. Melting points were determined using capillary method on DMP (M. 1Н NMR-spectra were recorded by Varian Mercury VX-200 device (company «Varian», USA solvent – (DMSO-d6, internal standard – ТМS. Elemental analysis of obtained compounds was produced on device Elementar Vario L cube. Results and discussion. We selected 3-benzyl-8-propyl xanthine as initial compound for our study. By its interaction with chloroacetic acid, chloroacetamide or propyl chloroacetate in DMF in the presence of calculated amount of NaHCO3 we synthesized 3-benzyl-8-propylxanthinyl-7-acetic acid its ester and amide. At the same time we found that obtaining of xanthinyl-7-acetic acid by hydrolysis of its ester produced with higher yield. On the next stage of our research we synthesized a number of water-soluble salts of 3-benzyl-8-propylxanthinyl-7-acetic acid by reaction of acid with different primary and secondary amines. The structures of all obtained compounds were

Acetate transiently inhibits myocardial contraction by increasing mitochondrial calcium uptake.

Science.gov (United States)

Schooley, James F; Namboodiri, Aryan M A; Cox, Rachel T; Bünger, Rolf; Flagg, Thomas P

2014-12-09

There is a close relationship between cardiovascular disease and cardiac energy metabolism, and we have previously demonstrated that palmitate inhibits myocyte contraction by increasing Kv channel activity and decreasing the action potential duration. Glucose and long chain fatty acids are the major fuel sources supporting cardiac function; however, cardiac myocytes can utilize a variety of substrates for energy generation, and previous studies demonstrate the acetate is rapidly taken up and oxidized by the heart. In this study, we tested the effects of acetate on contractile function of isolated mouse ventricular myocytes. Acute exposure of myocytes to 10 mM sodium acetate caused a marked, but transient, decrease in systolic sarcomere shortening (1.49 ± 0.20% vs. 5.58 ± 0.49% in control), accompanied by a significant increase in diastolic sarcomere length (1.81 ± 0.01 μm vs. 1.77 ± 0.01 μm in control), with a near linear dose response in the 1-10 mM range. Unlike palmitate, acetate caused no change in action potential duration; however, acetate markedly increased mitochondrial Ca(2+) uptake. Moreover, pretreatment of cells with the mitochondrial Ca(2+) uptake blocker, Ru-360 (10 μM), markedly suppressed the effect of acetate on contraction. Lehninger and others have previously demonstrated that the anions of weak aliphatic acids such as acetate stimulate Ca(2+) uptake in isolated mitochondria. Here we show that this effect of acetate appears to extend to isolated cardiac myocytes where it transiently modulates cell contraction.

Improving ethanol yield in acetate-reducing Saccharomyces cerevisiae by cofactor engineering of 6-phosphogluconate dehydrogenase and deletion of ALD6.

Science.gov (United States)

Papapetridis, Ioannis; van Dijk, Marlous; Dobbe, Arthur P A; Metz, Benjamin; Pronk, Jack T; van Maris, Antonius J A

2016-04-26

Acetic acid, an inhibitor of sugar fermentation by yeast, is invariably present in lignocellulosic hydrolysates which are used or considered as feedstocks for yeast-based bioethanol production. Saccharomyces cerevisiae strains have been constructed, in which anaerobic reduction of acetic acid to ethanol replaces glycerol formation as a mechanism for reoxidizing NADH formed in biosynthesis. An increase in the amount of acetate that can be reduced to ethanol should further decrease acetic acid concentrations and enable higher ethanol yields in industrial processes based on lignocellulosic feedstocks. The stoichiometric requirement of acetate reduction for NADH implies that increased generation of NADH in cytosolic biosynthetic reactions should enhance acetate consumption. Replacement of the native NADP(+)-dependent 6-phosphogluconate dehydrogenase in S. cerevisiae by a prokaryotic NAD(+)-dependent enzyme resulted in increased cytosolic NADH formation, as demonstrated by a ca. 15% increase in the glycerol yield on glucose in anaerobic cultures. Additional deletion of ALD6, which encodes an NADP(+)-dependent acetaldehyde dehydrogenase, led to a 39% increase in the glycerol yield compared to a non-engineered strain. Subsequent replacement of glycerol formation by an acetate reduction pathway resulted in a 44% increase of acetate consumption per amount of biomass formed, as compared to an engineered, acetate-reducing strain that expressed the native 6-phosphogluconate dehydrogenase and ALD6. Compared to a non-acetate reducing reference strain under the same conditions, this resulted in a ca. 13% increase in the ethanol yield on glucose. The combination of NAD(+)-dependent 6-phosphogluconate dehydrogenase expression and deletion of ALD6 resulted in a marked increase in the amount of acetate that was consumed in these proof-of-principle experiments, and this concept is ready for further testing in industrial strains as well as in hydrolysates. Altering the cofactor

Preparation of PbO nanoparticles by microwave irradiation and their application to Pb(II)-selective electrode based on cellulose acetate

International Nuclear Information System (INIS)

Li Shengying; Yang Wu; Chen Miao; Gao Jinzhang; Kang Jingwan; Youli, Q.

2005-01-01

Nanosized lead oxide particles were prepared by thermal decomposition of lead hydroxycarbonate synthesized under microwave irradiation. Urea and lead nitrate were used as the starting materials. Microstructure and morphology of the products were investigated by means of XRD, AFM, TEM, and IR absorption spectra. The results indicated that well crystallized, finely dispersed and spherical α-PbO nanoparticles with a size of ca. 30 nm were obtained. Meanwhile, an orthogonal phase β-PbO with a size of ca. 38 nm was also obtained when the calcinations temperature was up to 600 deg. C. In addition, a Pb(II)-selective electrode based on cellulose acetate was prepared using nanosized α-PbO powders synthesized. The electrode exhibited a Nernstian slope of 29±1 mV per decade in a linear range of 2.5x10 -5 mol L -1 to 1.0x10 -1 mol L -1 for Pb 2+ ion. The detection limit of this electrode is down to 8.0x10 -6 mol L -1 . This sensor has a short response time of about 10 s and could be used in a pH range of 2.0-8.0. High selectivity was obtained over a wide variety of metal ions

Selective Hydrogenolysis of Furfural Derivative 2-Methyltetrahydrofuran into Pentanediol Acetate and Pentanol Acetate over Pd/C and Sc(OTf)3 Cocatalytic System.

Science.gov (United States)

Zhang, Kun; Li, Xing-Long; Chen, Shi-Yan; Xu, Hua-Jian; Deng, Jin; Fu, Yao

2018-02-22

It is of great significance to convert platform molecules and their derivatives into high value-added alcohols, which have multitudinous applications. This study concerns systematic conversion of 2-methyltetrahydrofuran (MTHF), which is obtained from furfural, into 1-pentanol acetate (PA) and 1,4-pentanediol acetate (PDA). Reaction parameters, such as the Lewis acid species, reaction temperature, and hydrogen pressure, were investigated in detail. 1 H NMR spectroscopy and reaction dynamics study were also conducted to help clarify the reaction mechanism. Results suggested that cleavage of the primary alcohol acetate was less facile than that of the secondary alcohol acetate, with the main product being PA. A PA yield of 91.8 % (150 °C, 3 MPa H 2 , 30 min) was achieved by using Pd/C and Sc(OTf) 3 as a cocatalytic system and an 82 % yield of PDA was achieved (150 °C, 30 min) by using Sc(OTf) 3 catalyst. Simultaneously, the efficient conversion of acetic esters into alcohols by simple saponification was carried out and led to a good yield. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.

Science.gov (United States)

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

2012-03-16

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. Copyright © 2011 Elsevier B.V. All rights reserved.

Development of Acetic Acid Removal Technology for the UREX+Process

International Nuclear Information System (INIS)

Counce, Robert M.; Watson, Jack S.

2009-01-01

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 downstream steps can be avoided. 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

Development of Acetic Acid Removal Technology for the UREX+Process

Energy Technology Data Exchange (ETDEWEB)

Robert M. Counce; Jack S. Watson

2009-06-30

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.

Utilization of composite membrane polyethyleneglycol-polystyrene-cellulose acetate from pineapple leaf fibers in lowering levels of methyl orange batik waste

Science.gov (United States)

Delsy, E. V. Y.; Irmanto; Kazanah, F. N.

2017-02-01

Pineapple leaves are agricultural waste from the pineapple that the fibers can be utilized as raw material in cellulose acetate membranes. First, made pineapple leaf fibers into pulp and then converted into cellulose acetate by acetylation process in four stages consisting of activation, acetylation, hydrolysis and purification. Cellulose acetate then used as the raw material to manufacture composite membrane with addition of polystyrene and poly (ethylene glycol) as porogen. Composite membrane is made using phase inversion method with dichloromethane-acetone as a solvent. The result of FTIR analysis (Fourier transform infra-red) showed that the absorption of the carbonyl group (C=O) is at 1643.10 cm-1 and acetyl group (C-O ) at 1227.01 cm-1, with a molecular weight of 8.05 x 104 g/mol and the contents (rate) of acetyl is 37.31%. PS-PEG-CA composite membrane had also been characterized by measuring the water flux values and its application to decrease methyl orange content (level) in batik waste. The results showed that the water flux value is of 25.62 L/(m2.hour), and the decrease percentage of methyl orange content in batik waste is 71.53%.

ReaxFF molecular dynamics simulation of intermolecular structure formation in acetic acid-water mixtures at elevated temperatures and pressures

Science.gov (United States)

Sengul, Mert Y.; Randall, Clive A.; van Duin, Adri C. T.

2018-04-01

The intermolecular structure formation in liquid and supercritical acetic acid-water mixtures was investigated using ReaxFF-based molecular dynamics simulations. The microscopic structures of acetic acid-water mixtures with different acetic acid mole fractions (1.0 ≥ xHAc ≥ 0.2) at ambient and critical conditions were examined. The potential energy surface associated with the dissociation of acetic acid molecules was calculated using a metadynamics procedure to optimize the dissociation energy of ReaxFF potential. At ambient conditions, depending on the acetic acid concentration, either acetic acid clusters or water clusters are dominant in the liquid mixture. When acetic acid is dominant (0.4 ≤ xHAc), cyclic dimers and chain structures between acetic acid molecules are present in the mixture. Both structures disappear at increased water content of the mixture. It was found by simulations that the acetic acid molecules released from these dimer and chain structures tend to stay in a dipole-dipole interaction. These structural changes are in agreement with the experimental results. When switched to critical conditions, the long-range interactions (e.g., second or fourth neighbor) disappear and the water-water and acetic acid-acetic acid structural formations become disordered. The simulated radial distribution function for water-water interactions is in agreement with experimental and computational studies. The first neighbor interactions between acetic acid and water molecules are preserved at relatively lower temperatures of the critical region. As higher temperatures are reached in the critical region, these interactions were observed to weaken. These simulations indicate that ReaxFF molecular dynamics simulations are an appropriate tool for studying supercritical water/organic acid mixtures.

Acetic acid sclerotheraphy of renal cysts

International Nuclear Information System (INIS)

Hong, Hoon Pyo; Oh, Joo Hyeong; Yoon, Yup; Kong, Keun Young; Kim, Eui Jong; Goo, Jang Sung

1998-01-01

Sclerotherapy for renal cysts was performed, using 50% acetic acid as new sclerosing agent. We report the methods and results of this procedure. Fifteen patients underwent sclerotherapy for renal cyst, using 50% acetic acid. Because four patients were lost to follow-up, only 11 of the 15 were included in this study. The renal cysts, including one infected case, were diagnosed by ultrasonograpy (n=3D10) ormagnetic resonance imaging (n=3D1). The patient group consisted of four men and seven women(mean age, 59 years; range, 23-77). At first, the cyst was completely aspirated, and 25 volume% of aspirated volume was replaced with 50% sterile acetic acid through the drainage catheter. During the follwing 20 minutes, the patient changed position, and the acetic acid was then removed from the cyst. Finally, the drainage catheter was removed, after cleaning the cyst with saline. After treatment of infection by antibiotics and catheter drainage for 7 days, sclerotherapy in the infected case followed the same procedure. In order to observe changes in the size of renal cysts and recurrence, all patients were followed up by ultrasound between 2 and 8 months. We defined response to therapy as follows:complete regression as under 5 volume%, partial regression as 5-50 volume% and no response as more than 50 volume% of initial cyst volume. No clinically significant complication occured during the procedures or follow-up periods. All cysts regressed completely during follow-up of 8 months. Complete regression occurred as follows: two cysts at 2 months, seven cysts at 4 months, two cysts at 6 months. Two cysts showed residues at the last follow-up, at 4 and 6 months, respectively. The volume of residual cysts decreased to under 5 volume% of initial volume, however. Completely regressed cysts did not recurr during follow-up. Acetic acid sclerotherapy for renal cysts showed good results, regardless of the dilution of sclerosing agent with residual cyst fluid, and no significant

Depot Medroxyprogesterone Acetate (Depo-Provlera) as a Contrac ...

African Journals Online (AJOL)

Depot Medroxyprogesterone Acetate (Depo-Provlera) as a Contrac·eptive Preparation. Basil Bloch. Abstract. Experience with depot medroxyprogesterone acetate as a contraceptive preparation in 7 335 patients for a total of 38 714 months over a 3-year period is described. The discontinuation rate was 18.3% and the ...

Preparation, thermogravimetric study and infrared spectra of rare earth acetates

International Nuclear Information System (INIS)

Graehlert, X.; Starke, M.

1992-01-01

The anhydrous and the hydrated acetates of Ho, Er, Tm, Yb and Lu have been prepared. The compounds obtained have been investigated by thermogravimetric analysis and infrared spectroscopy. The thermal decomposition of the rare earth acetates may proceed via various steps. It depends on both the number of crystal water molecules in the acetates and the rare earth element's behaviour. (orig.)

Application of a modified BCR sequential extraction (three-step) procedure for the determination of extractable trace metal contents in a sewage sludge amended soil reference material (CRM 483), complemented by a three-year stability study of acetic acid and EDTA extractable metal content.

Science.gov (United States)

Rauret, G; López-Sánchez, J F; Sahuquillo, A; Barahona, E; Lachica, M; Ure, A M; Davidson, C M; Gomez, A; Lück, D; Bacon, J; Yli-Halla, M; Muntau, H; Quevauviller, P

2000-06-01

This paper provides additional data on a sewage sludge amended soil certified reference material, CRM 483, which was certified in 1997 for its EDTA and acetic acid extractable contents of some trace metals, following standardised extraction procedures. The additional work aimed to test the long-term stability of the material and the applicability of an improved version of the BCR three-step sequential extraction procedure on the sewage sludge amended soil (CRM 483). The paper demonstrates the CRM 483 long-term stability for EDTA and acetic acid extractable contents of Cd, Cr, Cu, Ni, Pb and Zn and gives the results (obtained in the framework of an interlaboratory study) for the extractable contents of the same elements in the CRM 483, following the BCR three-step sequential extraction scheme. The aqua regia extractable contents following the ISO 11466 Standard are also given. The data are given as indicative (not certified) values.

Survival of Acetate in Biodegraded Stream Water DOM: New Insights Based on NMR Spectroscopy

Science.gov (United States)

Whitty, S.; Waggoner, D. C.; Bowen, J. C.; Cory, R. M.; Kaplan, L.; Hatcher, P.

2017-12-01

DOM is a complex chemical mixture of high- (HMW) and low-molecular-weight (LMW) organic molecules that serve as the primary energy sources for heterotrophic bacteria in freshwater environments. However, there are still large uncertainties on the composition of DOM that is labile and thus rapidly metabolized. The current thinking is that labile DOM is primarily composed of monosaccharides, amino acids, and other LMW organic acids such as formic, acetic, or propionic among others, although some humic substances also are biologically labile. To test the contribution of LMW organic acids to the labile fraction of DOM, freshwater samples were collected from five streams within the Rio Tempisquito watershed in Costa Rica and subjected to differing degrees of biodegradation using a series of plug-flow bioreactors with residence times ranging from 0.5-150 min. Varying the residence times of bioreactors allows for separation and identification of labile from less labile to more recalcitrant DOM. The stream water fed into the bioreactors had DOC concentrations that ranged from 0.7-1.2 ppm C and the GF/F-filtered stream water as well as the bioreactor effluents were analyzed directly without pre-treatment using proton nuclear magnetic resonance spectroscopy (1H NMR). Small molecules dominated the 1H NMR spectra with the greatest changes, as a function of bioreactor residence time, in the carbohydrate, terminal methyl, and long-chain methylene structures. In contrast, acetate remained relatively constant after 150 min of bioreactor residence time, thus raising the question of why this inherently labile volatile fatty acid was not consumed by stream microbes colonizing bioreactors that otherwise metabolized approximately 35% of the total dissolved organic carbon present in the stream water. We suggest that acetate may resist biodegradation because it is complexed strongly with inorganic cations.

Biomaterial properties evaluation of poly(vinyl acetate- alt-maleic anhydride)/chitosan nanocapsules

Science.gov (United States)

Raţă, Delia Mihaela; Popa, Marcel; Chailan, Jean-François; Zamfir, Carmen Lăcrămioara; Peptu, Cătălina Anişoara

2014-08-01

Nanocapsules with diameter around 100 nm based on a natural polymer (chitosan) and a synthetic polymer poly(vinyl acetate- alt-maleic anhydride) [poly(MAVA)] by interfacial condensation method were prepared. The present study proposes a new type of biocompatible nanocapsules based on poly(vinyl acetate- alt-maleic anhydride-chitosan) (MCS) able to become a reliable support for inclusion and release of drugs. The spherical shape of the nanocapsules was evidenced by scanning electron microscopy. Nanocapsules presented a good Norfloxacin loading and release capacity. Haemocompatibility tests have demonstrated that the nanocapsules present a low toxicity and a good compatibility with sanguine medium. The biocompatibility properties of the nanocapsules after their intraperitoneal administration in rats were evidenced by histopathological examination of different organs (brain, liver, kidney, and lung). The results are encouraging and the nanocapsules can be used as controlled drug delivery systems.

Chromium (VI) reduction in acetate- and molasses-amended natural media: empirical model development

Energy Technology Data Exchange (ETDEWEB)

Hansen, Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boukhalfa, Hakim [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Karra, Satish [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wang, Dongping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vesselinov, Velimir Valentinov [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-11-21

Stimulating indigenous microbes to reduce heavy metals from highly toxic oxidized species to more benign reduced species is a promising groundwater remediation technique that has already seen successful field applications. Designing such a bio-remediation scheme requires a model incorporating the kinetics of nonlinear bio-geochemical interactions between multiple species. With this motivation, we performed a set of microcosm experiments in natural sediments and their indigenous pore water and microbes, generating simultaneous time series for concentrations of Cr(VI), an electron donor (both molasses and acetate were considered), and biomass. Molasses was found to undergo a rapid direct abiotic reaction which eliminated all Cr(VI) before any biomass had time to grow. This was not found in the acetate microcosms, and a distinct zero-order bio-reduction process was observed. Existing models were found inappropriate and a new set of three coupled governing equations representing these process dynamics were developed and their parameters calibrated against the time series from the acetate-amended microcosms. Cell suspension batch experiments were also performed to calibrate bio-reduction rates in the absence of electron donor and sediment. The donor used to initially grow the cells (molasses or acetate) was found not to impact the reduction rate constants in suspension, which were orders of magnitude larger than those explaining the natural media microcosm experiments. This suggests the limited utility of kinetics determined in suspension for remedial design. Scoping studies on the natural media microcosms were also performed, suggesting limited impact of foreign abiotic material and minimal effect of diffusion limitation in the vertical dimension. These analyses may be of independent value to future researchers.

Adding 11C-acetate to 18F-FDG at PET Examination Has an Incremental Value in the Diagnosis of Hepatocellular Carcinoma

Directory of Open Access Journals (Sweden)

Patricia Larsson

2012-04-01

Full Text Available Objective: The sensitivity of FDG at PET examination of Hepatocellular Carcinoma (HCC is restricted. In a few studies, all done in Oriental patients, PET-examination with 11C-acetate has shown a higher accuracy than with FDG. In the current study, the uptake of 11C-acetate has been compared with the uptake of FDG in the primary HCC in a cohort of Occidental patients. Material and Methods: 44 patients underwent PET-examination with both tracers with a mean of 9 days between the examinations. 26 patients had a microscopical diagnosis and 18 were diagnosed with multimodal radiological methods. At least one relevant radiological examination was available for comparison. Results: At visual evaluation, 13 of the HCC’s were positive at PET-examination using FDG and 34 were positive using 11C-acetate (p<0.001. Median tumor SUVmean of 11C-acetate was 4.7 and of FDG was 1.9 (p<0.001. There was also a higher uptake of 11C-acetate by the surrounding liver tissue than of FDG. Median liver SUVmean of 11C-acetate was 3.2 and of FDG it was 1.7 (p<0.001. This corresponded to a median tumour/liver tissue ratio for 11C-acetate of 1.4 and for FDG of 1.0 (p<0.05. Previous reports of a negative correlation between the uptake of the tracers were weakly supported. In 4 large tumors some portions being hot using one of the tracers were cold using the other tracer and vice versa. Conclusion: Adding registration with 11C-acetate to registration with FDG at PET-examination has an incremental value in the diagnosis of HCC. A higher tumor uptake of 11C-acetate cannot be taken full advantage of because of a higher uptake also by the surrounding liver tissue. (MIRT 2012;21:6-12

Solubility of perfumery and fragrance raw materials based on cyclohexane in 1-octanol under ambient and high pressures up to 900 MPa

International Nuclear Information System (INIS)

Domanska, Urszula; Morawski, Piotr; Piekarska, Maria

2008-01-01

The (solid + liquid) phase equilibria (SLE) of binary mixtures containing 1-octanol and fragrance raw materials based on cyclohexane were investigated. The systems {1-octanol (1) + cyclohexyl carboxylic acid (CCA), or cyclohexyl acetic acid (CAA), or cyclohexyl acetate (CA), or 2-cyclohexyl ethyl acetate (2CEA), or 2-cyclohexyl ethanol (2CE)(2)} have been measured by a dynamic method in wide range of temperatures from (220 to 320) K and ambient pressure. For all systems SLE diagrams were detected as eutectic mixtures with complete miscibility in the liquid phase. The experimental data were correlated by means of the Wilson and NRTL equations, utilizing parameters derived from the (solid + liquid) equilibrium. The root-mean-square deviations of the solubility temperatures for all calculated data are dependent upon the particular system and the particular equation used. Additionally, the SLE in binary mixture that contain {1-octanol (1) + CCA (2)} has been measured under very high pressures up to about 900 MPa at the temperature range from T = (303.15 to 353.15) K. The thermostatted apparatus for the measurements of transition pressures from the (liquid + solid) state was used. The freezing and melting temperatures at a constant composition increase monotonously with pressure. The high pressure experimental results obtained at isothermal conditions (p-x) were interpolated to more convenient T-x diagram. Data of the (pressure + temperature) composition relation at the high pressure (solid + liquid) phase equilibria was correlated by the polynomial based on the Yang model. The basic thermodynamic properties of pure substances viz. the melting point, enthalpy of fusion, enthalpy of solid-solid phase transition, and glass transition, have been determined by the differential scanning calorimetry (DSC)

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

DEFF Research Database (Denmark)

Voss, Bodil; Schjødt, Niels Christian; Grunwaldt, Jan-Dierk

2011-01-01

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....... 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....

EPR-based material modelling of soils

Science.gov (United States)

Faramarzi, Asaad; Alani, Amir M.

2013-04-01

In the past few decades, as a result of the rapid developments in computational software and hardware, alternative computer aided pattern recognition approaches have been introduced to modelling many engineering problems, including constitutive modelling of materials. The main idea behind pattern recognition systems is that they learn adaptively from experience and extract various discriminants, each appropriate for its purpose. In this work an approach is presented for developing material models for soils based on evolutionary polynomial regression (EPR). EPR is a recently developed hybrid data mining technique that searches for structured mathematical equations (representing the behaviour of a system) using genetic algorithm and the least squares method. Stress-strain data from triaxial tests are used to train and develop EPR-based material models for soil. The developed models are compared with some of the well-known conventional material models and it is shown that EPR-based models can provide a better prediction for the behaviour of soils. The main benefits of using EPR-based material models are that it provides a unified approach to constitutive modelling of all materials (i.e., all aspects of material behaviour can be implemented within a unified environment of an EPR model); it does not require any arbitrary choice of constitutive (mathematical) models. In EPR-based material models there are no material parameters to be identified. As the model is trained directly from experimental data therefore, EPR-based material models are the shortest route from experimental research (data) to numerical modelling. Another advantage of EPR-based constitutive model is that as more experimental data become available, the quality of the EPR prediction can be improved by learning from the additional data, and therefore, the EPR model can become more effective and robust. The developed EPR-based material models can be incorporated in finite element (FE) analysis.

[Determination of soil exchangeable base cations by using atomic absorption spectrophotometer and extraction with ammonium acetate].

Science.gov (United States)

Zhang, Yu-ge; Xiao, Min; Dong, Yi-hua; Jiang, Yong

2012-08-01

A method to determine soil exchangeable calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) by using atomic absorption spectrophotometer (AAS) and extraction with ammonium acetate was developed. Results showed that the accuracy of exchangeable base cation data with AAS method fits well with the national standard referential soil data. The relative errors for parallel samples of exchangeable Ca and Mg with 66 pair samples ranged from 0.02%-3.14% and 0.06%-4.06%, and averaged to be 1.22% and 1.25%, respectively. The relative errors for exchangeable K and Na with AAS and flame photometer (FP) ranged from 0.06%-8.39% and 0.06-1.54, and averaged to be 3.72% and 0.56%, respectively. A case study showed that the determination method for exchangeable base cations by using AAS was proven to be reliable and trustable, which could reflect the real situation of soil cation exchange properties in farmlands.

Acetate-intercalated Ni–In layered double hydroxides with low infrared emissivity: Synthesis, delamination and restacked to form the multilayer films

International Nuclear Information System (INIS)

Wang, Yongjuan; Zhou, Yuming; Zhang, Tao; He, Man; Bu, Xiaohai; Yang, Xiaoming

2014-01-01

The low-emissive membrane materials have potential applications in infrared detecting technologies. Herein, we report a novel LDHs film with low infrared emissivity, which was based on the deposition of the exfoliated LDH nanosheets. The monodispersed hexagonal plate-like particles of Ni–In–CO 3 2− LDHs were prepared by coprecipitation method with hydrothermal treatment under optimized conditions. In order to exfoliate the LDHs into nanosheets, acetate-intercalated Ni–In LDHs were prepared by anion-exchange of Ni–In–CO 3 2− LDHs. The as-prepared acetate-intercalated LDHs exhibited excellent delaminating behavior in water and unilamellar nanosheets were easily obtained. The resulting positive-charged nanosheets were assembled onto quartz substrates to produce the multilayer films. The infrared emissivity values of all the samples were characterized. It was found that the incorporation of Ni 2+ and In 3+ in the host layer significantly reduced the infrared emissivity value. Moreover, the value was further reduced by the fabrication of multilayer ultrathin films, which can be ascribed to the dense orderly structure and smooth surface morphology.

Raman spectroscopy of poly (3-hydroxybutyrate) modified with poly (vinyl acetate) by radiation- induced copolymerization

International Nuclear Information System (INIS)

Gonzalez, Maykel; Galego Fernandez, Norma; Ortiz del Toro, Pedro; Rapado, Manuel; Paredes

2007-01-01

Poly (3-hydroxybutyrate) (PHB) is an important material used in the field of medicine. However in common conditions, PHB has some deficiencies. It is very brittle and slightly hydrophobic polymer. This somewhat limit its applications. Radiation chemistry can be used to improve its chemical properties. In the present study, the substrate, modified by radiation-induced graft copolymerization with vinyl acetate (VAc), was characterized using FTIR and Raman spectroscopy. FTIR spectroscopy did not reveal any significant bands but Raman spectroscopy revealed the formation of a new band that characterize the material

Improved compaction of ZnO nano-powder triggered by the presence of acetate and its effect on sintering.

Science.gov (United States)

Dargatz, Benjamin; Gonzalez-Julian, Jesus; Guillon, Olivier

2015-04-01

The retention of nanocrystallinity in dense ceramic materials is still a challenge, even with the application of external pressure during sintering. The compaction behavior of high purity and acetate enriched zinc oxide (ZnO) nano-powders was investigated. It was found that acetate in combination with water plays a key role during the compaction into green bodies at moderate temperatures. Application of constant pressure resulted in a homogeneous green body with superior packing density (86% of theoretical value) at moderate temperature (85 °C) in the presence of water. In contrast, no improvement in density could be achieved if pure ZnO powder was used. This compaction behavior offers superior packing of the particles, resulting in a high relative density of the consolidated compact with negligible coarsening. Dissolution accompanying creep diffusion based matter transport is suggested to strongly support reorientation of ZnO particles towards densities beyond the theoretical limit for packing of ideal monosized spheres. Finally, the sintering trajectory reveals that grain growth is retarded compared to conventional processing up to 90% of theoretical density. Moreover, nearly no radial shrinkage was observed after sinter-forging for bodies performed with this advanced processing method.

Effect of acetic acid on Saccharomyces carlsbergensis ATCC 6269 batch ethanol production monitored by flow cytometry.

Science.gov (United States)

Freitas, Cláudia; Neves, Elisabete; Reis, Alberto; Passarinho, Paula C; da Silva, Teresa Lopes

2012-11-01

Bioethanol produced from lignocellulosic materials has been considered a sustainable alternative fuel. Such type of raw materials have a huge potential, but their hydrolysis into mono-sugars releases toxic compounds such as weak acids, which affect the microorganisms' physiology, inhibiting the growth and ethanol production. Acetic acid (HAc) is the most abundant weak acid in the lignocellulosic materials hydrolysates. In order to understand the physiological changes of Saccharomyces carlsbergensis when fermenting in the presence of different acetic acid (HAc) concentrations, the yeast growth was monitored by multi-parameter flow cytometry at same time that the ethanol production was assessed. The membrane potential stain DiOC(6)(3) fluorescence intensity decreased as the HAc concentration increased, which was attributed to the plasmic membrane potential reduction as a result of the toxic effect of the HAc undissociated form. Nevertheless, the proportion of cells with permeabilized membrane did not increase with the HAc concentration increase. Fermentations ending at lower external pH and higher ethanol concentrations depicted the highest proportions of permeabilized cells and cells with increased reactive oxygen species levels. Flow cytometry allowed monitoring, near real time (at-line), the physiological states of the yeast during the fermentations. The information obtained can be used to optimize culture conditions to improve bioethanol production.

[Conversion of acetic acid to methane by thermophiles

Energy Technology Data Exchange (ETDEWEB)

Zinder, S.H.

1993-01-01

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.

Isolation and Characterization of Acetate-Utilizing Anaerobes from a Freshwater Sediment.

Science.gov (United States)

Scholten, J.C.M.; Stams, A.J.M.

2000-12-01

Acetate-degrading anaerobic microorganisms in freshwater sediment were quantified by the most probable number technique. From the highest dilutions a methanogenic, a sulfate-reducing, and a nitrate-reducing microorganism were isolated with acetate as substrate. The methanogen (culture AMPB-Zg) was non-motile and rod-shaped with blunted ends (0.5-1 mm x 3-4 mm long). Doubling times with acetate at 30-35 degrees C were 5.6-8.1 days. The methanogen grew only on acetate. Analysis of the 16S rRNA sequence showed that AMPB-Zg is closely related to Methanosaeta concilii. The isolated sulfate-reducing bacterium (strain ASRB-Zg) was rod-shaped with pointed ends (0.5-0.7 mm x 1.5-3.5 mm long), weakly motile, spore forming, and gram positive. At the optimum growth temperature of 30 degrees C the doubling times with acetate were 3.9-5.3 days. The bacterium grew on a range of organic acids, such as acetate, butyrate, fumarate, and benzoate, but did not grow autotrophically with H2, CO2, and sulfate. The closest relative of strain ASRB-Zg is Desulfotomaculum acetoxidans. The nitrate-reducing bacterium (strain ANRB-Zg) was rod-shaped (0.5-0.7 mm x 0.7-1 mm long), weakly motile, and gram negative. Optimum growth with acetate occurred at 20-25 degrees C. The bacterium grew on a range of organic substrates, such as acetate, butyrate, lactate, and glucose, and did grow autotrophically with H2, CO2, and oxygen but not with nitrate. In the presence of acetate and nitrate, thiosulfate was oxidized to sulfate. Phylogenetically, the closest relative of strain ANRB-Zg is Variovorax paradoxus.

DFT-Based Explanation of the Effect of Simple Anionic Ligands on the Regioselectivity of the Heck Arylation of Acrolein Acetals

DEFF Research Database (Denmark)

Henriksen, Signe Teuber; Tanner, David Ackland; Cacchi, Sandro

2009-01-01

The Heck arylation of acrolein acetal has been studied computationally and compared to the corresponding reaction with allyl ethers. The reaction can be controlled to give either cinnamaldehydes or arylpropanoic esters by addition of different coordinating anions, acetate, or chloride. The comput...... reaction conditions. The difference between the two substrate classes could be rationalized in terms of relative hydride donating power of the two substrates....

Development of functional extruded snacks by utilizing paste shrimp (Acetes spp.): process optimization and quality evaluation.

Science.gov (United States)

Kumar, Raushan; Xavier, Ka Martin; Lekshmi, Manjusha; Dhanabalan, Vignaesh; Thachil, Madonna T; Balange, Amjad K; Gudipati, Venkateshwarlu

2018-04-01

Functional extruded snacks were prepared using paste shrimp powder (Acetes spp.), which is rich in protein. The process variables required for the preparation of extruded snacks was optimized using response surface methodology. Extrusion temperature (130-144 °C), level of Acetes powder (100-200 g kg -1 ) and feed moisture (140-200 g kg -1 ) were selected as design variables, and expansion ratio, porosity, hardness, crispness and thiobarbituric acid reactive substance value were taken as the response variables. Extrusion temperature significantly influenced all the response variables, while Acetes inclusion influenced all variables except porosity. Feed moisture content showed a significant quadratic effect on all responses and an interactive effect on expansion ratio and hardness. Shrimp powder incorporation increased the protein and mineral content of the final product. The extruded snack made with the combination of extrusion temperature 144.59 °C, feed moisture 178.5 g kg -1 and Acetes inclusion level 146.7 g kg -1 was found to be the best one based on sensory evaluation. The study suggests that use of Acetes species for the development of extruded snacks will serve as a means of utilization of Acetes as well as being a rich source of proteins for human consumption, which would otherwise remain unexploited as a by-catch. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Leuprorelin Acetate in Prostate Cancer: a European Update

Directory of Open Access Journals (Sweden)

Persad R

2002-01-01

Full Text Available This review provides an update on leuprorelin acetate, the world's most widely prescribed depot luteinising hormone-releasing hormone analogue. Leuprorelin acetate has been in clinical use in the palliative treatment of prostate cancer for more than 20 years, but advances continue to be made in terms of convenience and flexibility of administration, and in the incorporation of leuprorelin acetate into novel treatment regimens. The drug is administered in the form of a depot injection containing leuprorelin acetate microspheres, and is at least as effective in suppressing testosterone secretion as orchiectomy. In patients with prostate cancer, serum testosterone levels are reduced to castrate levels (= 50 ng/dl within 2-3 weeks of the first one-month depot injection of 3.75 mg or three-month depot injection of 11.25 mg. Both the one-month and three-month formulations are effective in delaying tumour progression and alleviating symptoms of locally advanced and metastatic prostate cancer. Tolerability is generally good, with side-effects reflecting effective testosterone suppression. Recent studies have investigated the place of leuprorelin acetate as part of continuous or intermittent maximal androgen blockade (MAB and in neoadjuvant therapy (ie, to reduce the size of the prostate and downsize the tumour before radiotherapy. Additional formulations and presentations are in development, including a six-month injection, with the aim of adding to the clinical flexibility and patient acceptability of this important palliative treatment for prostate cancer.

Citrate dialysate does not induce oxidative stress or inflammation in vitro as compared to acetate dialysate

Directory of Open Access Journals (Sweden)

Rafael Pérez-García

2017-11-01

, acetate-based dialysate increases oxidative stress and the total number of microvesicles and may induce another pro-inflammatory stimuli in uremic patients on haemodialysis. Citrate dialysates do not induce this activation, which could make them a suitable alternative in clinical practice. Resumen: El líquido de diálisis con citrato no induce in vitro estrés oxidativo ni inflamación en comparación con el acetato.El incremento de la acetatemia durante la sesión de hemodiálisis se ha asociado a una serie de alteraciones: aumento del estrés oxidativo, de las citocinas proinflamatorias y de la síntesis de óxido nítrico. El ácido cítrico puede jugar un papel alternativo al acetato como estabilizante del líquido de diálisis (LD. El citrato en comparación con el acetato tiene un patrón diferente en cuanto a la activación leucocitaria y del complemento. El objetivo de este estudio es comparar el acetato con el citrato en el LD respecto a su efecto inflamatorio en las células inmunocompetentes de la sangre. Material y métodos: El efecto del acetato o citrato fue investigado en sangre completa de pacientes urémicos y controles sanos in vitro, enfrentada a 4 tipos de LD: el LD 1, con 1 mmol/L de citrato y libre de acetato; LD 2, con 0,8 mmol/L de citrato y 0,3 mmol/L de acetato; LD 3, con 3 mmol/L de acetato sin citrato y LD 4, con 4 mmol/L de acetato sin citrato. Los tipos de células utilizados fueron: cultivo de monocitos humanos (THP-1; células mononucleares de sangre periférica (PBMC de controles sanos y pacientes urémicos en HD. Se determinó ICAM-1, la cuantificación de los niveles de especies reactivas de oxígeno (ROS y la cuantificación de microvesículas totales. Resultados: Los LD con acetato (L3 y L4 indujeron un incremento en la densidad de expresión de ICAM-1 en las células THP-1, no así los de citrato; con células inmunocompetentes de sujetos sanos los LD con acetato (L3 y L4 respecto a los con citrato (L1 y L2 observamos un

UV recording with vinyl acetate and muicle dye film

Science.gov (United States)

Toxqui-Lopez, S.; Olivares-Pérez, A.; Santacruz-Vazquez, V.; Fuentes-Tapia, I.; Ordoñez-Padilla, J.

2015-03-01

Nowadays, there are many types of holographic recording medium some of them are photopolymer systems that generally consist of a polymeric host matrix, photopolymerizable momomer, photosensitizing dye and charge transfer agent but some of them have an undesirable feature, the toxicity of their components. Therefore, the present research study material recording, vinyl acetate is selected as polymeric matrix and natural dye from "muicle plant" is used as the photoinitiation these components are not toxic. The films are fabricated using gravity settling method at room temperature by this method, uniform films is obtained with good optical quality. To characterize the medium, been obtained when the coherent reed light (632.8 nm) was sent normally to the grating.

21 CFR 529.1003 - Flurogestone acetate-impregnated vaginal sponge.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Flurogestone acetate-impregnated vaginal sponge... § 529.1003 Flurogestone acetate-impregnated vaginal sponge. (a) Specifications. Each vaginal sponge... ewes during their normal breeding season. (2) Limitations. Using applicator provided, insert sponge...

Acetalization of furfural with zeolites under benign reaction conditions

DEFF Research Database (Denmark)

Rubio-Caballeroa, Juan Miguel; Shunmugavel, Saravanamurugan; Maireles-Torres, Pedro

2014-01-01

Acetalization is a viable method to protect carbonyl functionalities in organic compounds and offers apotential synthetic strategy for synthesizing derived chemicals. In this work, several families of commer-cial zeolites have been employed as solid acid catalysts in the acetalization of furfural...

["Candidatus contubernalis alkalaceticum," an obligately syntrophic alkaliphilic bacterium capable of anaerobic acetate oxidation in a coculture with Desulfonatronum cooperativum].

Science.gov (United States)

Zhilina, T N; Zavarzina, D G; Kolganova, T V; Turova, T P; Zavarzin, G A

2005-01-01

From the silty sediments of the Khadyn soda lake (Tuva), a binary sulfidogenic bacterial association capable of syntrophic acetate oxidation at pH 10.0 was isolated. An obligately syntrophic, gram-positive, spore-forming alkaliphilic rod-shaped bacterium performs acetate oxidation in a syntrophic association with a hydrogenotrophic, alkaliphilic sulfate-reducing bacterium; the latter organism was previously isolated and characterized as the new species Desulfonatronum cooperativum. Other sulfate-reducing bacteria of the genera Desulfonatronum and Desulfonatronovibrio can also act as the hydrogenotrophic partner. Apart from acetate, the syntrophic culture can oxidize ethanol, propanol, isopropanol, serine, fructose, and isobutyric acid. Selective amplification of 16S rRNA gene fragments of the acetate-utilizing syntrophic component of the binary culture was performed; it was found to cluster with clones of uncultured gram-positive bacteria within the family Syntrophomonadaceae. The acetate-oxidizing bacterium is thus the first representative of this cluster obtained in a laboratory culture. Based on its phylogenetic position, the new acetate-oxidizing syntrophic bacterium is proposed to be assigned, in a Candidate status, to a new genus and species: "Candidatus Contubernalis alkalaceticum."

Final report on the safety assessment of ethoxyethanol and ethoxyethanol acetate.

Science.gov (United States)

Johnson, Wilbur

2002-01-01

Ethoxyethanol is an ether alcohol described as a solvent and viscosity-decreasing agent for use in cosmetics. Ethoxyethanol Acetate is the ester of Ethoxyethanol and acetic acid described as a solvent for use in cosmetics. Although these ingredients have been used in the past, neither ingredient is in current use. Ethoxyethanol is produced by reacting ethylene oxide with ethyl alcohol. Ethoxyethanol Acetate is produced via an esterification of Ethoxyethanol and acetic acid, acetic acid anhydride, or acetic chloride. Ethoxyethanol is metabolized to ethoxyacetaldehyde, which is further metabolized to ethoxyacetic acid, which is also a metabolite of Ethoxyethanol Acetate. Low to moderate acute inhalation toxicity is seen in animals studies. Acute oral toxicity studies in several species reported kidney damage, including extreme tubular degeneration. Kidney damage was also seen in acute dermal toxicity studies in rats and rabbits. Minor liver and kidney damage was also seen in short-term studies of rats injected subcutaneously with Ethoxyethanol, but was absent in dogs dosed intravenously. Mixed toxicity results were also seen in subchronic tests in mice and rats. Ethoxyethanol and Ethoxyethanol Acetate were mild to moderate eye irritants in rabbits; mild skin irritants in rabbits, and nonsensitizing in guinea pigs. Most genotoxicity tests were negative, but chromosome aberrations and sister-chromatid exchanges were among the positive results seen. Numerous reproductive and developmental toxicity studies, across several species, involving various routes of administration, indicate that Ethoxyethanol and Ethoxyethanol Acetate are reproductive toxicants and teratogens. Mild anemia was reported in individuals exposed occupationally to Ethoxyethanol, which resolved when the chemical was not used. Reproductive effects have been noted in males exposed occupationally to Ethoxyethanol. Although there are insufficient data to determine the potential carcinogenic effects of

Uptake of radiocarbon from plant rhizosphere based on geological disposal of TRU waste. Root-uptake of radiocarbon carbon derived from acetic acid

International Nuclear Information System (INIS)

Ogiyama, Shinichi; Takeda, Hiroshi; Uchida, Shigeo; Suzuki, Hiroyuki; Inubushi, Kazuyuki

2008-01-01

Hydroponic experiments were conducted to examine root-uptake of 14 C in the form of acetic acid by 3 kinds of plants (marigold, tall fescue, and paddy rice) based on buried transuranic (TRU) waste disposal. Also, chamber experiment was conducted to examine loss of 14 C as vaporized carbon dioxide (CO 2 ) from the experimental tessera (spatially heterogeneous environment). The distribution of radioactivity in the plant, mediums, and carbon dioxide ( 14 CO 2 ) in the chamber were determined, and the distribution of 14 C in the plant was visualized by the autoradiography. The plants absorbed and assimilated 14 C through the roots. The amount of 14 C in marigold and tall fescue were higher than that of paddy rice. However, the amounts of 14 C-acetic acid absorbed by all the plants through their roots were considered to be very small. More so, 14 CO 2 gas was released from the culture solution to the atmosphere; however, it was not enough for the plant to perform photosynthesis. Assimilation of 14 C in the plant shoots would be because of 14 C movement of inorganic forms such as CO 2 and HCO 3 - via the roots. Thus, the results indicated that the plants absorbed 14 C through the roots and assimilated it into the shoots or edible parts not because of uptake of 14 C-acetic acid but because of uptake of 14 C in inorganic forms. (author)

Analysis of Veterinary Drug and Pesticide Residues Using the Ethyl Acetate Multiclass/Multiresidue Method in Milk by Liquid Chromatography-Tandem Mass Spectrometry

Directory of Open Access Journals (Sweden)

Husniye Imamoglu

2016-01-01

Full Text Available A rapid and simple multiclass, ethyl acetate (EtOAc multiresidue method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS detection was developed for the determination and quantification of 26 veterinary drugs and 187 total pesticide residues in milk. Sample preparation was a simple procedure based on liquid–liquid extraction with ethyl acetate containing 0.1% acetic acid, followed by centrifugation and evaporation of the supernatant. The residue was dissolved in ethyl acetate with 0.1% acetic acid and centrifuged prior to LC-MS/MS analysis. Chromatographic separation of analytes was performed on an Inertsil X-Terra C18 column with acetic acid in methanol and water gradient. The repeatability and reproducibility were in the range of 2 to 13% and 6 to 16%, respectively. The average recoveries ranged from 75 to 120% with the RSD (n=18. The developed method was validated according to the criteria set in Commission Decision 2002/657/EC and SANTE/11945/2015. The validated methodology represents a fast and cheap alternative for the simultaneous analysis of veterinary drug and pesticide residues which can be easily extended to other compounds and matrices.

Surface properties of copper based cermet materials

International Nuclear Information System (INIS)

Voinea, M.; Vladuta, C.; Bogatu, C.; Duta, A.

2008-01-01

The paper presents the characterization of the surface properties of copper based cermets obtained by two different techniques: spray pyrolysis deposition (SPD) and electrodeposition. Copper acetate was used as precursor of Cu/CuO x cermet. The surface morphology was tailored by adding copolymers of maleic anhydride with controlled hydrophobia. The films morphology of Cu/CuO x was assessed using contact angle measurements and AFM analysis. The porous structures obtained via SPD lead to higher liquid adsorption rate than the electrodeposited films. A highly polar liquid - water is recommended as testing liquid in contact angle measurements, for estimating the porosity of copper based cermets, while glycerol can be used to distinguish among ionic and metal predominant structures. Thus, contact angle measurements can be used for a primary evaluation of the films morphology and, on the other hand, of the ratio between the cermet components

Fate and residues of trenbolone acetate in edible tissues from sheep amd calves implanted with tritium-labeled trenbolone acetate

Energy Technology Data Exchange (ETDEWEB)

Evrard, P.; Maghuin-Rogister, G.; Rico, A.G. (Univ. of Liege (Belgium))

1989-06-01

In order to study the fate and residues of trenbolone acetate in edible tissues, two groups of six animals from two ruminant species (ewes and calves) were implanted with (3H)trenbolone acetate. The distribution of extractable radioactive residues was measured in liver, kidney and muscle. We found that the largest proportion of residues was not extractable and thus was considered as covalently bound residues. The proportion of the main extractable metabolites (17 alpha-trenbolone, trendione, 17 beta-trenbolone) was measured. The evaluation of the distribution of trenbolone acetate metabolites directly soluble in water showed that unknown metabolite(s) were predominant. The covalent binding to nucleic acids was measured. It was so low that it was not detectable. The results are discussed in light of the data presented in the scientific report on anabolic agents in animal production from the European scientific working group.

Fate and residues of trenbolone acetate in edible tissues from sheep amd calves implanted with tritium-labeled trenbolone acetate

International Nuclear Information System (INIS)

Evrard, P.; Maghuin-Rogister, G.; Rico, A.G.

1989-01-01

In order to study the fate and residues of trenbolone acetate in edible tissues, two groups of six animals from two ruminant species (ewes and calves) were implanted with [3H]trenbolone acetate. The distribution of extractable radioactive residues was measured in liver, kidney and muscle. We found that the largest proportion of residues was not extractable and thus was considered as covalently bound residues. The proportion of the main extractable metabolites (17 alpha-trenbolone, trendione, 17 beta-trenbolone) was measured. The evaluation of the distribution of trenbolone acetate metabolites directly soluble in water showed that unknown metabolite(s) were predominant. The covalent binding to nucleic acids was measured. It was so low that it was not detectable. The results are discussed in light of the data presented in the scientific report on anabolic agents in animal production from the European scientific working group

Conjugation chemistry through acetals toward a dextran-based delivery system for controlled release of siRNA

KAUST Repository

Cui, Lina; Cohen, Jessica L.; Chu, Crystal K.; Wich, Peter R.; Kierstead, Paul H.; Frechet, Jean

2012-01-01

allows the release of therapeutics under acidic conditions, such as that of the endocytic compartments of cells, regenerating the original free polysaccharide in the end. The physical and chemical behavior of these acetal groups can be adjusted

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

Energy Technology Data Exchange (ETDEWEB)

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

2002-04-01

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

Solubility of fragrance raw materials in water: Experimental study, correlations, and Mod. UNIFAC (Do) predictions

International Nuclear Information System (INIS)

Domanska, Urszula; Paduszynski, Kamil; Niszczota, Zaneta K.

2011-01-01

The (liquid + liquid) and (solid + liquid) phase equilibria of nine binary mixtures containing fragrance raw materials (FRM) such as aliphatic ketones and compounds based on cyclohexane with water were investigated. The systems {2-heptanone, or 2-nonanone, or 2-undecanone, or 2-tridecanone, or cyclohexyl carboxylic acid (CCA), or cyclohexyl acetic acid (CAA), or 2-cyclohexyl ethanol (2CE) or cyclohexyl acetate (CA), or 2-cyclohexyl ethyl acetate (2CEA) + water (2)} have been measured by a dynamic method in wide range of temperatures from (290 to 360) K and ambient pressure. For all systems immiscibility in the liquid phase was detected. The experimental data was correlated by means of the NRTL equation, utilizing parameters derived from the (liquid + liquid) equilibrium. Additionally, the binary mixtures were predicted with the Mod. UNIFAC (Do) model, with known from literature parameters, with very good results.

Development of Chitosan Acetate Films for Transdermal Delivery of ...

African Journals Online (AJOL)

Methods: Chitosan acetate was chemically modified with acetaldehyde and the solution was prepared with 1 % acetic acid, in which was dissolved propranolol hydrochloride, was cast as films in Petri dish and characterised by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and ...

Single and combined effects of acetic acid, furfural, and sugars on the growth of the pentose-fermenting yeast Meyerozyma guilliermondii.

Science.gov (United States)

Perna, Michelle Dos Santos Cordeiro; Bastos, Reinaldo Gaspar; Ceccato-Antonini, Sandra Regina

2018-02-01

The tolerance of the pentose-fermenting yeast Meyerozyma guilliermondii to the inhibitors released after the biomass hydrolysis, such as acetic acid and furfural, was surveyed. We first verified the effects of acetic acid and cell concentrations and initial pH on the growth of a M. guilliermondii strain in a semi-synthetic medium containing acetic acid as the sole carbon source. Second, the single and combined effects of furfural, acetic acid, and sugars (xylose, arabinose, and glucose) on the sugar uptake, cell growth, and ethanol production were also analysed. Growth inhibition occurred in concentrations higher than 10.5 g l -1 acetic acid and initial pH 3.5. The maximum specific growth rate (µ) was 0.023 h -1 and the saturation constant (ks) was 0.75 g l -1 acetic acid. Initial cell concentration also influenced µ. Acetic acid (initial concentration 5 g l -1 ) was co-consumed with sugars even in the presence of 20 mg l -1 furfural without inhibition to the yeast growth. The yeast grew and fermented sugars in a sugar-based medium with acetic acid and furfural in concentrations much higher than those usually found in hemicellulosic hydrolysates.

Potentiometric titrations in anhydrous acetic acid

International Nuclear Information System (INIS)

Le Port, L.

1966-03-01

The method used for studying anhydrous acetic acid is potentiometry with a glass electrode. We have in this way studied the titration of common inorganic acids (HClO 4 - HBr - H 2 SO 4 - HCl - HNO 3 - H 3 PO 4 ) and of some metallic salts. Furthermore we have shown that complex acids are formed between HCl and some metallic chlorides. An analysis of the titration curves for the inorganic acids against pyridinium chloride has made it possible to calculate a certain number of values for the dissociation pK of these acids and of the corresponding pyridinium salts. The titration of metallic perchlorates constitutes a method of studying the stability of acetates; we have thus been able to draw up a classification for some of these acetates. The metallic chlorides studied fall into two groups according to their behaviour in weak or strong acids. The differences have been explained on the basis of the role played by solvolysis. In the third part we have studied the acidic properties of mixtures of HCl with certain metallic chlorides. This work has demonstrated the existence, in certain cases, of acid complexes of the type (HCl) m MCl n . (author) [fr

The ratio of acetate-to-glucose oxidation in astrocytes from a single 13C NMR spectrum of cerebral cortex.

Science.gov (United States)

Marin-Valencia, Isaac; Hooshyar, M Ali; Pichumani, Kumar; Sherry, A Dean; Malloy, Craig R

2015-01-01

The (13) C-labeling patterns in glutamate and glutamine from brain tissue are quite different after infusion of a mixture of (13) C-enriched glucose and acetate. Two processes contribute to this observation, oxidation of acetate by astrocytes but not neurons, and preferential incorporation of α-ketoglutarate into glutamate in neurons, and incorporation of α-ketoglutarate into glutamine in astrocytes. The acetate:glucose ratio, introduced previously for analysis of a single (13) C NMR spectrum, provides a useful index of acetate and glucose oxidation in the brain tissue. However, quantitation of relative substrate oxidation at the cell compartment level has not been reported. A simple mathematical method is presented to quantify the ratio of acetate-to-glucose oxidation in astrocytes, based on the standard assumption that neurons do not oxidize acetate. Mice were infused with [1,2-(13) C]acetate and [1,6-(13) C]glucose, and proton decoupled (13) C NMR spectra of cortex extracts were acquired. A fit of those spectra to the model indicated that (13) C-labeled acetate and glucose contributed approximately equally to acetyl-CoA (0.96) in astrocytes. As this method relies on a single (13) C NMR spectrum, it can be readily applied to multiple physiologic and pathologic conditions. Differences in (13) C labeling of brain glutamate and glutamine have been attributed to metabolic compartmentation. The acetate:glucose ratio, introduced for description of a (13) C NMR (nuclear magnetic resonance) spectrum, is an index of glucose and acetate oxidation in brain tissue. A simple mathematical method is presented to quantify the ratio of acetate-to-glucose oxidation in astrocytes from a single NMR spectrum. As kinetic analysis is not required, the method is readily applicable to analysis of tissue extracts. α-KG = alpha-ketoglutarate; CAC = citric acid cycle; GLN = glutamine; GLU = glutamate. © 2014 International Society for Neurochemistry.

Effects of culture conditions on acetic acid production by bacteria ...

African Journals Online (AJOL)

SARAH

2015-11-30

Nov 30, 2015 ... acid under certain culture conditions similar to cocoa fermentation stress. However ... Keywords: Acetic acid bacteria, acetic acid production, Cocoa fermentation, culture conditions ..... American Society Microbiology Press, pp.

Evolution of the zinc compound nanostructures in zinc acetate single-source solution

International Nuclear Information System (INIS)

Wang Ying; Li Yinhua; Zhou Zhengzhi; Zu Xihong; Deng Yulin

2011-01-01

A series of nanostructured zinc compounds with different nanostructures such as nanobelts, flake-like, flower-like, and twinning crystals was synthesized using zinc acetate (Zn(Ac) 2 ) as a single-source. The evolution of the zinc compounds from layered basic zinc acetate (LBZA) to bilayered basic zinc acetate (BLBZA) and twinned ZnO nano/microcrystal was studied. The low-angle X-ray diffraction spectra indicate the layered spacing is 1.34 and 2.1 nm for LBZA and BLBZA, respectively. The Fourier transform infrared (FTIR) spectra results confirmed that the bonding force of acetate anion with zinc cations decreases with the phase transformation from Zn(Ac) 2 to BLBZA, and finally to LBZA. The OH − groups gradually replaced the acetate groups coordinated to the matrix zinc cation, and the acetate groups were released completely. Finally, the Zn(OH) 2 and ZnO were formed at high temperature. The conversion process from Zn(Ac) 2 to ZnO with release of acetate anions can be described as Zn(Ac) 2 → BLBZA → LBZA → Zn(OH) 2 → ZnO.

ATP-Citrate Lyase Controls a Glucose-to-Acetate Metabolic Switch

Directory of Open Access Journals (Sweden)

Steven Zhao

2016-10-01

Full Text Available Mechanisms of metabolic flexibility enable cells to survive under stressful conditions and can thwart therapeutic responses. Acetyl-coenzyme A (CoA plays central roles in energy production, lipid metabolism, and epigenomic modifications. Here, we show that, upon genetic deletion of Acly, the gene coding for ATP-citrate lyase (ACLY, cells remain viable and proliferate, although at an impaired rate. In the absence of ACLY, cells upregulate ACSS2 and utilize exogenous acetate to provide acetyl-CoA for de novo lipogenesis (DNL and histone acetylation. A physiological level of acetate is sufficient for cell viability and abundant acetyl-CoA production, although histone acetylation levels remain low in ACLY-deficient cells unless supplemented with high levels of acetate. ACLY-deficient adipocytes accumulate lipid in vivo, exhibit increased acetyl-CoA and malonyl-CoA production from acetate, and display some differences in fatty acid content and synthesis. Together, these data indicate that engagement of acetate metabolism is a crucial, although partial, mechanism of compensation for ACLY deficiency.

ATP-Citrate Lyase Controls a Glucose-to-Acetate Metabolic Switch.

Science.gov (United States)

Zhao, Steven; Torres, AnnMarie; Henry, Ryan A; Trefely, Sophie; Wallace, Martina; Lee, Joyce V; Carrer, Alessandro; Sengupta, Arjun; Campbell, Sydney L; Kuo, Yin-Ming; Frey, Alexander J; Meurs, Noah; Viola, John M; Blair, Ian A; Weljie, Aalim M; Metallo, Christian M; Snyder, Nathaniel W; Andrews, Andrew J; Wellen, Kathryn E

2016-10-18

Mechanisms of metabolic flexibility enable cells to survive under stressful conditions and can thwart therapeutic responses. Acetyl-coenzyme A (CoA) plays central roles in energy production, lipid metabolism, and epigenomic modifications. Here, we show that, upon genetic deletion of Acly, the gene coding for ATP-citrate lyase (ACLY), cells remain viable and proliferate, although at an impaired rate. In the absence of ACLY, cells upregulate ACSS2 and utilize exogenous acetate to provide acetyl-CoA for de novo lipogenesis (DNL) and histone acetylation. A physiological level of acetate is sufficient for cell viability and abundant acetyl-CoA production, although histone acetylation levels remain low in ACLY-deficient cells unless supplemented with high levels of acetate. ACLY-deficient adipocytes accumulate lipid in vivo, exhibit increased acetyl-CoA and malonyl-CoA production from acetate, and display some differences in fatty acid content and synthesis. Together, these data indicate that engagement of acetate metabolism is a crucial, although partial, mechanism of compensation for ACLY deficiency. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Acetic Acid Bacteria as Symbionts of Insects

KAUST Repository

Crotti, Elena; Chouaia, Bessem; Alma, Alberto; Favia, Guido; Bandi, Claudio; Bourtzis, Kostas; Daffonchio, Daniele

2016-01-01

Acetic acid bacteria (AAB) are being increasingly described as associating with different insect species that rely on sugar-based diets. AAB have been found in several insect orders, among them Diptera, Hemiptera, and Hymenoptera, including several vectors of plant, animal, and human diseases. AAB have been shown to associate with the epithelia of different organs of the host, they are able to move within the insect’s body and to be transmitted horizontally and vertically. Here, we review the ecology of AAB and examine their relationships with different insect models including mosquitoes, leafhoppers, and honey bees. We also discuss the potential use of AAB in symbiont-based control strategies, such as “Trojan-horse” agents, to block the transmission of vector-borne diseases.

Acetic Acid Bacteria as Symbionts of Insects

KAUST Repository

Crotti, Elena

2016-06-14

Acetic acid bacteria (AAB) are being increasingly described as associating with different insect species that rely on sugar-based diets. AAB have been found in several insect orders, among them Diptera, Hemiptera, and Hymenoptera, including several vectors of plant, animal, and human diseases. AAB have been shown to associate with the epithelia of different organs of the host, they are able to move within the insect’s body and to be transmitted horizontally and vertically. Here, we review the ecology of AAB and examine their relationships with different insect models including mosquitoes, leafhoppers, and honey bees. We also discuss the potential use of AAB in symbiont-based control strategies, such as “Trojan-horse” agents, to block the transmission of vector-borne diseases.

Formulation of cyclodextrin inclusion complex-based orally disintegrating tablet of eslicarbazepine acetate for improved oral bioavailability

International Nuclear Information System (INIS)

Desai, Samixa; Poddar, Aditi; Sawant, Krutika

2016-01-01

The present investigation was aimed towards developing a beta-cyclodextrin (β-CD) solid dispersion (SD) based orally disintegrating tablet (ODT) of eslicarbazepine acetate (ESL), for improving the dissolution and providing fast onset of anti-epileptic action. Optimum ratio of ESL and β-CD was determined by Job's plot. Thereafter, solid dispersions were prepared by solvent evaporation method and evaluated for yield, assay, Differential scanning calorimetry (DSC), Fourier transform infra red spectroscopy (FTIR), X-ray diffraction (XRD), and in vitro dissolution. Optimized SD was compressed into ODT by direct compression using super disintegrants and evaluated for wetting time, drug content, in vitro drug release and in vivo studies. The results of DSC, FTIR and XRD analysis supported the formation of inclusion complex. An improved dissolution with 99.95 ± 2.80% drug release in 60 min was observed in comparison to 24.85 ± 2.96% release from a plain drug suspension. Tablets with crosspovidone as a super disintegrant showed the least disintegration time of 24.66 ± 1.52 s and higher in vitro drug release against marketed tablets. In vivo studies indicated that the formulated tablets had 2 times higher bioavailability than marketed tablets. Thus, the developed β-CD–ESL SD-ODT could provide faster onset of action and higher bioavailability, which would be beneficial in case of epileptic seizures. - Highlights: • β-cyclodextrin–eslicarbazepine acetate complex developed with enhanced solubility. • Formulated Orally disintegrating tablets (ODT) disintegrated within 30 s. • Bioavailability from ODT was 2 times higher than marketed tablets. • Onset of action for ODT was also faster than marketed tablets. • Formulated ODT would aid epileptic patients incapable of swallowing tablets.

Formulation of cyclodextrin inclusion complex-based orally disintegrating tablet of eslicarbazepine acetate for improved oral bioavailability

Energy Technology Data Exchange (ETDEWEB)

Desai, Samixa; Poddar, Aditi; Sawant, Krutika, E-mail: dr_krutikasawant@yahoo.co.in

2016-01-01

The present investigation was aimed towards developing a beta-cyclodextrin (β-CD) solid dispersion (SD) based orally disintegrating tablet (ODT) of eslicarbazepine acetate (ESL), for improving the dissolution and providing fast onset of anti-epileptic action. Optimum ratio of ESL and β-CD was determined by Job's plot. Thereafter, solid dispersions were prepared by solvent evaporation method and evaluated for yield, assay, Differential scanning calorimetry (DSC), Fourier transform infra red spectroscopy (FTIR), X-ray diffraction (XRD), and in vitro dissolution. Optimized SD was compressed into ODT by direct compression using super disintegrants and evaluated for wetting time, drug content, in vitro drug release and in vivo studies. The results of DSC, FTIR and XRD analysis supported the formation of inclusion complex. An improved dissolution with 99.95 ± 2.80% drug release in 60 min was observed in comparison to 24.85 ± 2.96% release from a plain drug suspension. Tablets with crosspovidone as a super disintegrant showed the least disintegration time of 24.66 ± 1.52 s and higher in vitro drug release against marketed tablets. In vivo studies indicated that the formulated tablets had 2 times higher bioavailability than marketed tablets. Thus, the developed β-CD–ESL SD-ODT could provide faster onset of action and higher bioavailability, which would be beneficial in case of epileptic seizures. - Highlights: • β-cyclodextrin–eslicarbazepine acetate complex developed with enhanced solubility. • Formulated Orally disintegrating tablets (ODT) disintegrated within 30 s. • Bioavailability from ODT was 2 times higher than marketed tablets. • Onset of action for ODT was also faster than marketed tablets. • Formulated ODT would aid epileptic patients incapable of swallowing tablets.

Measurement of acetates in air using differential ion mobility spectrometer

Science.gov (United States)

Szczurek, Andrzej; Maciejewska, Monika; Zajiczek, Żaneta; Maziejuk, Mirosław

2017-11-01

Volatile organic compounds are one of the most important group of air pollutants. Potential health and environmental problems resulting from their emission prompted the requirement for monitoring these species. It motivates development of new measurement techniques which are fast, cost effective, reliable and field deployable. One of novel approaches is ion mobility spectrometry. It dwells on ion separation in electric field, based on differences in ion mobility. Many variants of this method are developed. In this wok, differential ion mobility spectrometry (DMS) was considered in respect of acetate measurements in air. It was demonstrated that DMS offers linear response to methyl, ethyl, propyl and butyl acetate in concentration range from 0.3 ppm to 7 ppm. Positive ions spectrum has to be utilised for this purpose. We showed that fragments of DMS spectrum which secure linearity are compound-specific. The obtained results are promising from the application point of view.

Megestrol acetate in patients with AIDS-related cachexia.

Science.gov (United States)

Von Roenn, J H; Armstrong, D; Kotler, D P; Cohn, D L; Klimas, N G; Tchekmedyian, N S; Cone, L; Brennan, P J; Weitzman, S A

1994-09-15

To compare the effects of oral suspensions of megestrol acetate, 800 mg/d, and placebo on body weight in patients with acquired immunodeficiency syndrome (AIDS)-related weight loss. Randomized, double-blind, placebo-controlled trial. Outpatient community and university patient care setting. Consecutive patients with AIDS who had substantial weight loss and anorexia were enrolled. Of 271 patients, 270 and 195 were evaluable for safety and efficacy, respectively. Patients were randomly assigned to receive placebo or megestrol acetate (100 mg, 400 mg, or 800 mg) daily for 12 weeks. The primary efficacy criterion was weight gain. Patients were evaluated at 4-week intervals for changes in weight and body composition, caloric intake, sense of well-being, toxic effects, and appetite. For evaluable patients receiving 800 mg of megestrol acetate per day, 64.2% gained 2.27 kg (5 pounds) or more compared with 21.4% of patients receiving placebo (P < 0.001). An intent-to-treat analysis showed significant differences (P = 0.002) between those receiving placebo and those receiving 800 mg of megestrol acetate for the number of patients who gained 2.27 kg (5 pounds) or more (8 of 32 [25%] compared with 38 of 61 [62.3%], respectively). Compared with patients receiving placebo at the time of maximum weight change, evaluable patients receiving megestrol acetate, 800 mg/d, reported improvement in overall well-being and had an increase in mean weight gain (-0.725 compared with 3.54 kg [-1.6 compared with +7.8 pounds]; P < 0.001), lean body mass (-0.772 compared with +1.14 kg [-1.7 compared with +2.5 pounds]; P < 0.001), appetite grade (P < 0.001), and caloric intake (-107 compared with +645.6 calories/d; P = 0.001). In patients with AIDS-related weight loss, megestrol acetate can stimulate appetite, food intake, and statistically significant weight gain that is associated with a patient-reported improvement in an overall sense of well-being.

Assessment of ethylene vinyl-acetate copolymer samples exposed to γ-rays via linearity analyses

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Lucas N. de; Nascimento, Eriberto O. do; Schimidt, Fernando [Instituto Federal de Educação, Ciência e Tecnologia de Goiás (IFG), Goiânia, GO (Brazil); Antonio, Patrícia L.; Caldas, Linda V.E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

Materials with the potential to become dosimeters are of interest in radiation physics. In this research, the materials were analyzed and compared in relation to their linearity ranges. Samples of ethylene vinyl-acetate copolymer (EVA) were irradiated with doses from 10 Gy to 10 kGy using a {sup 60}Co Gamma-Cell system 220 and evaluated with the FTIR technique. The linearity analyses were applied through two methodologies, searching for linear regions in their response. The results show that both applied analyses indicate linear regions in defined dose interval. The radiation detectors EVA can be useful for radiation dosimetry in intermediate and high doses. (author)

Solubility of perfumery and fragrance raw materials based on cyclohexane in 1-octanol under ambient and high pressures up to 900 MPa

Energy Technology Data Exchange (ETDEWEB)

Domanska, Urszula [Physical Chemistry Division, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)], E-mail: ula@ch.pw.edu.pl; Morawski, Piotr; Piekarska, Maria [Physical Chemistry Division, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

2008-04-15

The (solid + liquid) phase equilibria (SLE) of binary mixtures containing 1-octanol and fragrance raw materials based on cyclohexane were investigated. The systems {l_brace}1-octanol (1) + cyclohexyl carboxylic acid (CCA), or cyclohexyl acetic acid (CAA), or cyclohexyl acetate (CA), or 2-cyclohexyl ethyl acetate (2CEA), or 2-cyclohexyl ethanol (2CE)(2){r_brace} have been measured by a dynamic method in wide range of temperatures from (220 to 320) K and ambient pressure. For all systems SLE diagrams were detected as eutectic mixtures with complete miscibility in the liquid phase. The experimental data were correlated by means of the Wilson and NRTL equations, utilizing parameters derived from the (solid + liquid) equilibrium. The root-mean-square deviations of the solubility temperatures for all calculated data are dependent upon the particular system and the particular equation used. Additionally, the SLE in binary mixture that contain {l_brace}1-octanol (1) + CCA (2){r_brace} has been measured under very high pressures up to about 900 MPa at the temperature range from T = (303.15 to 353.15) K. The thermostatted apparatus for the measurements of transition pressures from the (liquid + solid) state was used. The freezing and melting temperatures at a constant composition increase monotonously with pressure. The high pressure experimental results obtained at isothermal conditions (p-x) were interpolated to more convenient T-x diagram. Data of the (pressure + temperature) composition relation at the high pressure (solid + liquid) phase equilibria was correlated by the polynomial based on the Yang model. The basic thermodynamic properties of pure substances viz. the melting point, enthalpy of fusion, enthalpy of solid-solid phase transition, and glass transition, have been determined by the differential scanning calorimetry (DSC)

Effect of acetic acid on lipid accumulation by glucose-fed activated sludge cultures

Energy Technology Data Exchange (ETDEWEB)

Mondala, Andro; Hernandez, Rafael; French, Todd; McFarland, Linda; Sparks, Darrell; Holmes, William; Haque, Monica

2012-01-01

The effect of acetic acid, a lignocellulose hydrolysis by-product, on lipid accumulation by activated sludge cultures grown on glucose was investigated. This was done to assess the possible application of lignocellulose as low-cost and renewable fermentation substrates for biofuel feedstock production. Results: Biomass yield was reduced by around 54% at a 2 g L -1 acetic acid dosage but was increased by around 18% at 10 g L -1 acetic acid dosage relative to the control run. The final gravimetric lipid contents at 2 and 10 g L -1 acetic acid levels were 12.5 + 0.7% and 8.8 + 3.2% w/w, respectively, which were lower than the control (17.8 + 2.8% w/w). However, biodiesel yields from activated sludge grown with acetic acid (5.6 + 0.6% w/w for 2 g L -1 acetic acid and 4.2 + 3.0% w/w for 10 g L -1 acetic acid) were higher than in raw activated sludge (1-2% w/w). The fatty acid profiles of the accumulated lipids were similar with conventional plant oil biodiesel feedstocks. Conclusions: Acetic acid enhanced biomass production by activated sludge at high levels but reduced lipid production. Further studies are needed to enhance acetic acid utilization by activated sludge microorganisms for lipid biosynthesis.

Development of starch-based materials

NARCIS (Netherlands)

Habeych Narvaez, E.A.

2009-01-01

Starch-based materials show potential as fully degradable plastics. However, the current
applicability of these materials is limited due to their poor moisture tolerance and
mechanical properties. Starch is therefore frequently blended with other polymers to make
the material more

Cellobiose as a model system to reveal cellulose dissolution mechanism in acetate-based ionic liquids: Density functional theory study substantiated by NMR spectra.

Science.gov (United States)

Cao, Bobo; Du, Jiuyao; Du, Dongmei; Sun, Haitao; Zhu, Xiao; Fu, Hui

2016-09-20

Cellulose dissolution mechanism in acetate-based ionic liquids was systematically studied in Nuclear Magnetic Resonance (NMR) spectra and Density Functional Theory (DFT) methods by using cellobiose and 1-butyl-3-methylimidazolium acetate (BmimAc) as a model system. The solubility of cellulose in ionic liquid increased with temperature increase in the range of 90-140°C. NMR spectra suggested OAc(-) preferred to form stronger hydrogen bonds with hydrogen of hydroxyl in cellulose. Electrostatic potential method was employed to predict the most possible reaction sites and locate the most stable configuration. Atoms in molecules (AIM) theory was used to study the features of bonds at bond critical points and the variations of bond types. Simultaneously, noncovalent interactions were characterized and visualized by employing reduced density gradient analysis combined with Visual Molecular Dynamics (VMD) program. Natural bond orbital (NBO) theory was applied to study the noncovalent nature and characterize the orbital interactions between cellobiose and Bmim[OAc]. Copyright © 2016 Elsevier Ltd. All rights reserved.

Materials data base for fusion reactors-I

International Nuclear Information System (INIS)

Iwata, S.; Nogami, A.; Ishino, S.; Mishima, Y.; Takao, Y.; Aruga, T.; Shiraishi, K.

1982-01-01

The materials data base is a set of experimental and/or calculated data being compiled to meet the broad needs for materials data by taking advantage of the data base management systems. In this paper the objective of such computerized data base is described and the characteristics of fusion reactor materials are discussed from the viewpoint of the data base development. The near-term emphasis of the development has been put on the irradiation data for 316 type stainless steels. Through the test of this small data base, it can be concluded that this approach is promising for materials data base management and for the establishment of the interface between fusion reactor designer and materials investigator. (orig.)

Lactate Biosensor Based on Cellulose Acetate Membrane Bound Lactate Oxidase

Directory of Open Access Journals (Sweden)

Suman

2007-05-01

Full Text Available Lactate biosensor was fabricated by immobilizing lactate oxidase in cellulose acetate membrane and by mounting over the sensing part of Pt electrode (working and connected to Ag/AgCl electrode (reference along with auxillary electrode through potentiostat. The enzyme electrode was anodically polarized at +400 mV to generate electrons from H2O2, which was formed from oxidation of serum lactate by immobilized lactate oxidase. The minimum detection limit of the electrode was 0.1mmoles/L and sensitivity of the sensor was 0.008 mA/mM/L lactate. Assay coefficients of variation were < 2% .A good correlation (r=0.99 was found between lactate values obtained by colorimetric method and lactate biosensor. The self-life of the biosensor was 18 days at 4ºC and enzyme electrode can be re-used 150 times without any significant loss in enzyme activity.

Polyphosphazine-based polymer materials

Science.gov (United States)

Fox, Robert V.; Avci, Recep; Groenewold, Gary S.

2010-05-25

Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

Characterization of cellulose acetate obtained from sugarcane bagasse by {sup 1}H-NMR; Caracterizacao de acetato de celulose obtido a partir do bagaco de cana-de-acucar por {sup 1}H-RMN

Energy Technology Data Exchange (ETDEWEB)

Cerqueira, Daniel A.; Rodrigues Filho, Guimes, E-mail: d.a.cerqueira@gmail.co [Universidade Federal de Uberlendia (IQ/UFU), MG (Brazil). Inst. de Quimica; Carvalho, Rui A. [Universidade de Coimbra (UC) (Portugal). Dept. de Bioquimica; Valente, Artur J.M. [Universidade de Coimbra (UC) (Portugal). Dept. de Quimica

2009-07-01

Cellulose from sugarcane bagasse was used for synthesizing cellulose acetate with different degrees of substitution, which were characterized by {sup 1}H-NMR through the relationship between the peak areas of the hydrogen atoms present at the acetate groups (-(C=O)OCH{sub 3} ) and the peaks of the hydrogen bonded to the carbon atoms of the glycosidic rings. Suppression was carried out in order to remove the peak of residual water in the materials and the peak related to impurities in cellulose triacetate. Degree of substitution values obtained through the resonance deconvolution were compared to those obtained by chemical determination through an acid-base titration. The determined degrees of substitution of the cellulose samples were 2.94 and 2.60. (author)

Catalytic oxidation of butyl acetate over silver-loaded zeolites

International Nuclear Information System (INIS)

Wong, Cheng Teng; Abdullah, Ahmad Zuhairi; Bhatia, Subhash

2008-01-01

The performance of silver-loaded zeolite (HY and HZSM-5) catalysts in the oxidation of butyl acetate as a model volatile organic compound (VOC) was studied. The objective was to find a catalyst with superior activity, selectivity towards deep oxidation product and stability. The catalyst activity was measured under excess oxygen condition in a packed bed reactor operated at gas hourly space velocity (GHSV) = 15,000-32,000 h -1 , reaction temperature between 150 and 500 deg. C and butyl acetate inlet concentration of 1000-4000 ppm. Both AgY and AgZSM-5 catalysts exhibited high activity in the oxidation of butyl acetate. Despite lower silver content, AgY showed better activity, attributed to better metal dispersion, surface characteristics and acidity, and its pore system. Total conversion of butyl acetate was achieved at above 400 deg. C. The oxidation of butyl acetate followed a simple power law model. The reaction orders, n and m were evaluated under differential mode by varying the VOC partial pressure between 0.004 and 0.018 atm and partial pressure of oxygen between 0.05 and 0.20 atm. The reaction rate was independent of oxygen concentration and single order with respect to VOC concentration. The activation energies were 19.78 kJ/mol for AgY and 32.26 kJ/mol for AgZSM-5, respectively

Iron oxides alter methanogenic pathways of acetate in production water of high-temperature petroleum reservoir.

Science.gov (United States)

Pan, Pan; Hong, Bo; Mbadinga, Serge Maurice; Wang, Li-Ying; Liu, Jin-Feng; Yang, Shi-Zhong; Gu, Ji-Dong; Mu, Bo-Zhong

2017-09-01

Acetate is a key intermediate in anaerobic crude oil biodegradation and also a precursor for methanogenesis in petroleum reservoirs. The impact of iron oxides, viz. β-FeOOH (akaganéite) and magnetite (Fe 3 O 4 ), on the methanogenic acetate metabolism in production water of a high-temperature petroleum reservoir was investigated. Methane production was observed in all the treatments amended with acetate. In the microcosms amended with acetate solely about 30% of the acetate utilized was converted to methane, whereas methane production was stimulated in the presence of magnetite (Fe 3 O 4 ) resulting in a 48.34% conversion to methane. Methane production in acetate-amended, β-FeOOH (akaganéite)-supplemented microcosms was much faster and acetate consumption was greatly improved compared to the other conditions in which the stoichiometric expected amounts of methane were not produced. Microbial community analysis showed that Thermacetogenium spp. (known syntrophic acetate oxidizers) and hydrogenotrophic methanogens closely related to Methanothermobacter spp. were enriched in acetate and acetate/magnetite (Fe 3 O 4 ) microcosms suggesting that methanogenic acetate metabolism was through hydrogenotrophic methanogenesis fueled by syntrophic acetate oxidizers. The acetate/β-FeOOH (akaganéite) microcosms, however, differed by the dominance of archaea closely related to the acetoclastic Methanosaeta thermophila. These observations suggest that supplementation of β-FeOOH (akaganéite) accelerated the production of methane further, driven the alteration of the methanogenic community, and changed the pathway of acetate methanogenesis from hydrogenotrophic methanogenesis fueled by syntrophic acetate oxidizers to acetoclastic.

Antinociceptive activities of crude methanolic extract and phases, n-butanolic, chloroformic and ethyl acetate from Caulerpa racemosa (Caulerpaceae

Directory of Open Access Journals (Sweden)

Everton T. Souza

Full Text Available In this study, we attempted to identify the possible antinociceptive actions of n-butanolic phase, chloroformic phase, ethyl acetate phase and crude methanolic extract obtained from Caulerpa racemosa. This seaweed is cosmopolitan in world, mainly in tropical regions. The n-butanolic, chloroformic, ethyl acetate phases and crude methanolic extract, all administered orally in the concentration of 100 mg/kg, reduced the nociception produced by acetic acid by 47.39%, 70.51%, 76.11% and 72.24%, respectively. In the hotplate test the chloroformic and ethyl acetate phase were activite in this models. In the neurogenic phase on formalin test, were observed that crude methanolic extract (51.77%, n-butanolic phase (35.12%, chloroformic phase (32.70% and indomethacin (32.06% were effective in inhibit the nociceptive response. In the inflammatory phase, only the ethyl acetate phase (75.43% and indomethacin (47.83% inhibited significantly the nociceptive response. Based on these data, we can infer that the ethyl acetate phase shows a significant anti-inflammatory profile, whose power has not yet been determined. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s responsible for the antinociceptive action and also to identify other active principles present in Caulerpa racemosa.

Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

Science.gov (United States)

Tu, Yunjie; Schuler, Andrew J

2013-04-16

Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure.

New kaolinite phases expanded through intercalation with potassium acetate

International Nuclear Information System (INIS)

Frost, R.L.; Kristof, J.; Kloprogge, J.T.

1998-01-01

Full text: Changes in the hydroxyl surfaces of potassium acetate-intercalated kaolinite have been studied over the ambient to predehydroxylation temperature range using a combination of X-ray diffraction and Raman spectroscopy. Upon intercalation, the kaolinite expanded along the c-axis direction to 13.88 Angstroms. Upon heating the intercalation complex over the 50 to 300 deg C range, X-ray diffraction shows the existence of three additional intercalation phases with d-spacings of 9.09, 9.60, and 11.47 Angstroms. The amount of each phase is temperature dependent. These expansions are reversible and upon cooling the intercalation complex returned to its original spacing. The 13.88 Angstroms phase only existed in the presence of water. It is proposed that the expanded kaolinite intercalation phases result from the orientation of the acetate within the intercalation complex. The Raman spectra of the hydroxyl-stretching region (Frost and van der Gaast, 1997) of potassium acetate-intercalated kaolinite has been obtained under an atmosphere of both air and nitrogen using a thermal stage over the 25 to 300 deg C temperature range (Johansson et al., 1998). Raman spectra of the C-C, C=O stretching and O-C-O bending modes show that at least two types of acetate are present in the intercalation complex. These are assigned to two different orientations of the acetate. At 25 deg C, a new band at 3606 cm -1 attributed to the inner surface hydroxyl hydrogen bonded to the acetate ion is observed with a concomitant loss of intensity in the bands attributed to the inner surface hydroxyls (Frost and Kristof, 1997, Frost et al.,1997). Heating the intercalation complex to 50 deg C results in two hydroxyl-stretching frequencies at 3594 and 3604 cm -1 . This change in frequencies is ascribed to phase changes of the potassium acetate-intercalated kaolinite. At 100 deg C, the bands shift to 3600 and 3613 cm -1 . These shifts in frequencies are assigned to new kaolinite expanded phases. At

Modelling and Simulation of the Batch Hydrolysis of Acetic ...

African Journals Online (AJOL)

The kinetic modelling of the batch synthesis of acetic acid from acetic anhydride was investigated. The kinetic data of the reaction was obtained by conducting the hydrolysis reaction in a batch reactor. A dynamic model was formulated for this process and simulation was carried out using gPROMS® an advanced process ...

Evaluation of Turmeric (Curcuma longa) effects in preventing consequences of lead acetate in male rats

OpenAIRE

Ali-Reza Ayoubi; Reza Valizadeh; Arash Omidi; Mohsen Abolfazli

2014-01-01

Background and Aim: Diabetes is one of the mortality factors in the world. Nutritional and environmental pollution with heavy metals, especially lead, exacerbates diabetic condition. The curcumin in Turmeric has antioxidant properties and therapeutic effects on the treatment of some diseases such as diabetes. Materials and Methods: In an interventional experiment designed to investigate the protective effect of turmeric powder on consequences of lead acetate on some blood parameters in the...

Diamond-based materials for biomedical applications

CERN Document Server

Narayan, Roger

2013-01-01

Carbon is light-weight, strong, conductive and able to mimic natural materials within the body, making it ideal for many uses within biomedicine. Consequently a great deal of research and funding is being put into this interesting material with a view to increasing the variety of medical applications for which it is suitable. Diamond-based materials for biomedical applications presents readers with the fundamental principles and novel applications of this versatile material. Part one provides a clear introduction to diamond based materials for medical applications. Functionalization of diamond particles and surfaces is discussed, followed by biotribology and biological behaviour of nanocrystalline diamond coatings, and blood compatibility of diamond-like carbon coatings. Part two then goes on to review biomedical applications of diamond based materials, beginning with nanostructured diamond coatings for orthopaedic applications. Topics explored include ultrananocrystalline diamond for neural and ophthalmologi...

Modeling of acetate-type fermentation of sugar-containing wastewater under acidic pH conditions.

Science.gov (United States)

Huang, Liang; Pan, Xin-Rong; Wang, Ya-Zhou; Li, Chen-Xuan; Chen, Chang-Bin; Zhao, Quan-Bao; Mu, Yang; Yu, Han-Qing; Li, Wen-Wei

2018-01-01

In this study, a kinetic model was developed based on Anaerobic Digestion Model No. 1 to provide insights into the directed production of acetate and methane from sugar-containing wastewater under low pH conditions. The model sufficiently described the dynamics of liquid-phase and gaseous products in an anaerobic membrane bioreactor by comprehensively considering the syntrophic bioconversion steps of sucrose hydrolysis, acidogenesis, acetogenesis and methanogenesis under acidic pH conditions. The modeling results revealed a significant pH-dependency of hydrogenotrophic methanogenesis and ethanol-producing processes that govern the sucrose fermentative pathway through changing the hydrogen yield. The reaction thermodynamics of such acetate-type fermentation were evaluated, and the implications for process optimization by adjusting the hydraulic retention time were discussed. This work sheds light on the acid-stimulated acetate-type fermentation process and may lay a foundation for optimization of resource-oriented processes for treatment of food wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Skin impression with acetate tape in Demodex canis and Scarcoptes scabiei var. vulpes diagnosis

Directory of Open Access Journals (Sweden)

D.T. Pereira

2015-02-01

Full Text Available This study compares the efficacy of skin impression with acetate tape and the deep skin scraping test to find D. canis and S. scabiei in dogs. During six months, 134 samples were collected by both techniques from 115 dogs treated at the dermatology service of the Veterinary Hospital of the Federal University of Santa Maria (HVU-UFSM. Of these patients, 27 had demodicosis and 12 had scabies. The impression with acetate tape test (ITT was shown to be significantly superior to the deep skin scraping test (DSST in finding D. canis and S. scabiei mites (p = 0.007. Based on our results we could conclude that acetate tape impression is a reliable method for diagnosing and monitoring therapy of dermatopathies caused by mites and can be used to replace the traditional deep skin scraping method. In addition, since it is less traumatic for the dog, this method shows more acceptance by the owner.

Production of itaconic acid from acetate by engineering acid-tolerant Escherichia coli W.

Science.gov (United States)

Noh, Myung Hyun; Lim, Hyun Gyu; Woo, Sung Hwa; Song, Jinyi; Jung, Gyoo Yeol

2018-03-01

Utilization of abundant and cheap carbon sources can effectively reduce the production cost and enhance the economic feasibility. Acetate is a promising carbon source to achieve cost-effective microbial processes. In this study, we engineered an Escherichia coli strain to produce itaconic acid from acetate. As acetate is known to inhibit cell growth, we initially screened for a strain with a high tolerance to 10 g/L of acetate in the medium, and the W strain was selected as the host. Subsequently, the WC strain was obtained by overexpression of cad (encoding cis-aconitate decarboxylase) using a synthetic promoter and 5' UTR. However, the WC strain produced only 0.13 g/L itaconic acid because of low acetate uptake. To improve the production, the acetate assimilating pathway and glyoxylate shunt pathway were amplified by overexpression of pathway genes as well as its deregulation. The resulting strain, WCIAG4 produced 3.57 g/L itaconic acid (16.1% of theoretical maximum yield) after 88 hr of fermentation with rapid acetate assimilation. These efforts support that acetate can be a potential feedstock for biochemical production with engineered E. coli. © 2017 Wiley Periodicals, Inc.

New liquid crystalline materials based on two generations of dendronised cyclophosphazenes.

Science.gov (United States)

Jiménez, Josefina; Laguna, Antonio; Gascón, Elena; Sanz, José Antonio; Serrano, José Luis; Barberá, Joaquín; Oriol, Luis

2012-12-21

A divergent approach was used for the synthesis of dendritic structures based on a cyclotriphosphazene core with 12 or 24 hydroxyl groups, by starting from [N(3)P(3)(OC(6)H(4)OH-4)(6)] and using an acetal-protected 2,2-di(hydroxymethyl)propionic anhydride as the acylating agent. Hydroxyl groups in these first- and second-generation dendrimers, G1-(OH)(12) or G2-(OH)(24), were then condensed in turn with mono- or polycatenar pro-mesogenic acids to study their ability to promote self-assembly into liquid crystalline structures. Reactions were monitored by using (31)P{(1)H} and (1)H NMR spectroscopy and the chemical structure of the resulting materials was confirmed by using different spectroscopic techniques and mass spectrometry (MALDI-TOF MS). The results were in accordance with monodisperse, fully functionalised cyclotriphosphazene dendrimers. Thermal and liquid crystalline properties were studied by using optical microscopy, differential scanning calorimetry and X-ray diffraction. The dendrimer with 12 4-pentylbiphenyl mesogenic units gives rise to columnar rectangular organisation, whereas the one with 24 pentylbiphenyl units does not exhibit mesomorphic behaviour. In the case of materials that contain polycatenar pro-mesogenic units with two aromatic rings (A4 vs. A5), the incorporation of a short flexible spacer connected to the periphery of the dendron (acid A5) was needed to achieve mesomorphic organisation. In this case, both dendrimer generations G1 A5 and G2 A5 exhibit a hexagonal columnar mesophase. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lactate- and acetate-based cross-feeding interactions between selected strains of lactobacilli, bifidobacteria and colon bacteria in the presence of inulin-type fructans.

Science.gov (United States)

Moens, Frédéric; Verce, Marko; De Vuyst, Luc

2017-01-16

Cross-feeding interactions were studied between selected strains of lactobacilli and/or bifidobacteria and butyrate-producing colon bacteria that consume lactate but are not able to degrade inulin-type fructans (ITF) in a medium for colon bacteria (supplemented with ITF as energy source and acetate when necessary). Degradation of oligofructose by Lactobacillus acidophilus IBB 801 and inulin by Lactobacillus paracasei 8700:2 and Bifidobacterium longum LMG 11047 resulted in the release of free fructose into the medium and the production of mainly lactate (lactobacilli) and acetate (B. longum LMG 11047). During bicultures of Lb. acidophilus IBB 801 and Anaerostipes caccae DSM 14662 T on oligofructose, the latter strain converted lactate (produced by the former strain from oligofructose) into butyrate and gases, but only in the presence of acetate. During bicultures of Lb. paracasei 8700:2 and A. caccae DSM 14662 T or Eubacterium hallii DSM 17630 on inulin, the butyrate-producing strains consumed low concentrations of lactate and acetate generated by inulin degradation by the Lactobacillus strain. As more acetate was produced during tricultures of Lb. paracasei 8700:2 and B. longum LMG 11047, which degraded inulin simultaneously, and A. caccae DSM 14662 T or E. hallii DSM 17630, a complete conversion of lactate into butyrate and gases by these butyrate-producing strains occurred. Therefore, butyrate production by lactate-consuming, butyrate-producing colon bacterial strains incapable of ITF degradation, resulted from cross-feeding of monosaccharides and lactate by an ITF-degrading Lactobacillus strain and acetate produced by a Bifidobacterium strain. Copyright © 2016 Elsevier B.V. All rights reserved.

Syntrophic acetate oxidation in industrial CSTR biogas digesters.

Science.gov (United States)

Sun, Li; Müller, Bettina; Westerholm, Maria; Schnürer, Anna

2014-02-10

The extent of syntrophic acetate oxidation (SAO) and the levels of known SAO bacteria and acetate- and hydrogen-consuming methanogens were determined in sludge from 13 commercial biogas production plants. Results from these measurements were statistically related to the prevailing operating conditions, through partial least squares (PLS) analysis. This revealed that high abundance of microorganisms involved in SAO was positively correlated with relatively low abundance of aceticlastic methanogens and high concentrations of free ammonia (>160 mg/L) and volatile fatty acids (VFA). Temperature was identified as another influencing factor for the population structure of the syntrophic acetate oxidising bacteria (SAOB). Overall, there was a high abundance of SAOB in the different digesters despite differences in their operating parameters, indicating that SAOB are an enduring and important component of biogas-producing consortia. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites

DEFF Research Database (Denmark)

Peltola, Heidi; Madsen, Bo; Joffe, Roberts

2011-01-01

Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt% and fiber contents of 10 and 40 wt% were used. The compounded composites were injection molded to tensile test specimens...... was noticed. A reduction of fiber length along the increasing fiber content and the decreasing plasticizer content was also detected. This reduction originated from the increasing shear forces during compounding, which again depended on the increased viscosity of the material. Hemp fibers were shown to remain...... longer and fibrillate more than flax fibers, leading to higher aspect ratio. Thus, the reinforcement efficiency of hemp fibers by the processing was improved, in contrast with flax fibers. In addition, the analysis of fiber dispersion and orientation showed a good dispersion of fibers in the matrix...

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

Science.gov (United States)

Lewer, P.; Bandurski, R. S.

1987-01-01

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

Chemistry and electrochemistry in trifluoroacetic acid. Comparison with acetic acid

International Nuclear Information System (INIS)

Petit, Gerard

1972-01-01

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

Solubility of fragrance raw materials in water: Experimental study, correlations, and Mod. UNIFAC (Do) predictions

Energy Technology Data Exchange (ETDEWEB)

Domanska, Urszula, E-mail: ula@ch.pw.edu.p [Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Paduszynski, Kamil; Niszczota, Zaneta K. [Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

2011-01-15

The (liquid + liquid) and (solid + liquid) phase equilibria of nine binary mixtures containing fragrance raw materials (FRM) such as aliphatic ketones and compounds based on cyclohexane with water were investigated. The systems {l_brace}2-heptanone, or 2-nonanone, or 2-undecanone, or 2-tridecanone, or cyclohexyl carboxylic acid (CCA), or cyclohexyl acetic acid (CAA), or 2-cyclohexyl ethanol (2CE) or cyclohexyl acetate (CA), or 2-cyclohexyl ethyl acetate (2CEA) + water (2){r_brace} have been measured by a dynamic method in wide range of temperatures from (290 to 360) K and ambient pressure. For all systems immiscibility in the liquid phase was detected. The experimental data was correlated by means of the NRTL equation, utilizing parameters derived from the (liquid + liquid) equilibrium. Additionally, the binary mixtures were predicted with the Mod. UNIFAC (Do) model, with known from literature parameters, with very good results.

Dynamic changes of carbon isotope apparent fractionation factor to describe transition to syntrophic acetate oxidation during cellulose and acetate methanization.

Science.gov (United States)

Vavilin, Vasily A; Rytov, Sergey V

2017-05-01

To identify predominant metabolic pathway for cellulose methanization new equations that take into account dynamics of 13C are added to the basic model of cellulose methanization. The correct stoichiometry of hydrolysis, acidogenesis, acetogenesis and methanogenesis steps including biomass is considered. Using experimental data by Laukenmann et al. [Identification of methanogenic pathway in anaerobic digesters using stable carbon isotopes. Eng. Life Sci. 2010;10:1-6], who reported about the importance of ace`tate oxidation during mesophilic cellulose methanization, the model confirmed that, at high biomass concentration of acetate oxidizers, the carbon isotope fractionation factor amounts to about 1.085. The same model, suggested firstly for cellulose degradation, was used to describe, secondly, changes in, and in methane and carbon dioxide during mesophylic acetate methanization measured by Grossin-Debattista [Fractionnements isotopiques (13C/12C) engendres par la methanogenese: apports pour la comprehension des processus de biodegradation lors de la digestion anaerobie [doctoral thesis]. 2011. Bordeaux: Universite Bordeaux-1;2011. Available from: http://ori-oai.u-bordeaux1.fr/pdf/2011/GROSSIN-DEBATTISTA_JULIEN_2011.pdf . French].The model showed that under various ammonium concentrations, at dominating acetoclastic methanogenesis, the value decreases over time to a low level (1.016), while at dominating syntrophic acetate oxidation, coupled with hydrogenotrophic methanogenesis, slightly increases, reaching 1.060 at the end of incubation.

Acetate biodegradation by anaerobic microorganisms at high pH and high calcium concentration

International Nuclear Information System (INIS)

Yoshida, Takahiro

2011-01-01

Acetate biodegradation at a high pH and a high calcium concentration was examined to clarify the effect of bacterial activity on the migration of organic 14 C compounds in cementitious repositories. Tamagawa river sediment or Teganuma pond sediment was anaerobically cultured with 5 mM acetate and 10 mM nitrate at pH 9.5-12 at 30 o C. After 20 and 90 days, the acetate concentration of the culture medium was analyzed and found to have decreased below 5 mM at pH ≤ 11. On the other hand, it did not decrease when either sediment was incubated in the absence of nitrate. These results suggest that nitrate-reducing bacteria can biodegrade acetate under more alkaline conditions than the reported pH range in which nitrate-reducing bacteria can exhibit activity. Acetate biodegradation was also examined at a high calcium concentration. Sediments were anaerobically cultured at pH 9.5 with 5 mM acetate and 10 mM nitrate in solution, equilibrated with ordinary Portland cement hydrate, in which the Ca concentration was 14.6 mM. No decrease in acetate concentration after incubation of the sediments was observed, nor was it lower than in the absence of cementitious composition, suggesting that kinetics of acetate biodegradation by anaerobic microorganisms is lowered by a high Ca concentration. - Research highlights: → Acetate biodegradation at a high pH and a high calcium concentration was examined to clarify the effect of bacterial activity on the migration of organic 14 C compounds in cementitious repositories. → Nitrate-reducing bacteria can biodegrade acetate at pH ≤ 11. → Kinetics of acetate biodegradation by anaerobic microorganisms might be lowered by a high Ca concentration.

Naturally Compatible: Starch Acetate/Cellulosic Fiber Composites. I. Processing and Properties

DEFF Research Database (Denmark)

Nättinen, Kalle; Hyvärinen, Sari; Joffe, Roberts

2010-01-01

Composite compounds based on hemp and flax fibers in triethyl citrate plasticized starch acetate were prepared by melt processing. For better properties and processability, compounds with plasticizer contents in the range 20-35 wt% were screened. Composites were prepared with fiber contents up...... to 50 wt%. The composite mechanical properties were measured from injection molded test specimens. A Young's modulus of 8.3 GPa and stress at maximum load of 51 MPa were obtained with 40 wt% flax fiber in a plasticized starch acetate with 20 wt% triethyl citrate. Decreasing the plasticizer...... and increasing the fiber content, the tensile properties were consistently improved. An almost linear relation between fiber content and the tensile properties was found. The increase of the fiber content first improved the impact strength, but at higher fiber contents resulted in a reduction of impact strength...

Improving the environmental profile of wood panels via co-production of ethanol and acetic acid.

Science.gov (United States)

Earles, J Mason; Halog, Anthony; Shaler, Stephen

2011-11-15

The oriented strand board (OSB) biorefinery is an emerging technology that could improve the building, transportation, and chemical sectors' environmental profiles. By adding a hot water extraction stage to conventional OSB panel manufacturing, hemicellulose polysaccharides can be extracted from wood strands and converted to renewably sourced ethanol and acetic acid. Replacing fossil-based gasoline and acetic acid has the potential to reduce greenhouse gas (GHG) emissions, among other possible impacts. At the same time, hemicellulose extraction could improve the environmental profile of OSB panels by reducing the level of volatile organic compounds (VOCs) emitted during manufacturing. In this study, the life cycle significance of such GHG, VOC, and other emission reductions was investigated. A process model was developed based on a mix of laboratory and industrial-level mass and energy flow data. Using these data a life cycle assessment (LCA) model was built. Sensitive process parameters were identified and used to develop a target production scenario for the OSB biorefinery. The findings suggest that the OSB biorefinery's deployment could substantially improve human and ecosystem health via reduction of select VOCs compared to conventionally produced OSB, gasoline, and acetic acid. Technological advancements are needed, however, to achieve desirable GHG reductions.

Thermal Analysis and Degradation Kinetics of Dextran and Highly Substituted Dextran Acetates

International Nuclear Information System (INIS)

Amin, M.; Hussain, M. A.; Shahwar, D.; Hussain, M.

2015-01-01

Dextran acetates were synthesized to study their thermal behavior in comparison with pure dextran. The results have indicated that dextran is significantly stabilized after acetylation. Dextran acetates are thermally 65-74 degree C more stable as compared to pure dextran in terms of maximum decomposition temperature (Td/sub m/). Likewise, degradation of dextran acetates also starts and ends later than dextran as shown by relatively higher initial (Td/sub i/) 3-33 degree C and final decomposition temperature (Td/sub f/) 55-69 degree C. The dextran acetates can be arranged in increasing order of thermal stability: dextran acetate DS 2.91 < dextran DS 2.98 < dextran acetate DS 3. The activation energy (Ea) of dextran and dextran acetates was calculated with the help of Friedman, Broido and Chang kinetic models while order of reaction (n) was calculated from thermal data using Chang and Kissinger models. Several other important parameters were also calculated including frequency factor (Z), enthalpy (delta H), Gibbs free energy (delta G) and entropy (delta S). The integral procedural decomposition temperature (IPDT) and comprehensive index of intrinsic thermal stability (ITS) was also drawn from TG curves using Doyle's method. The dependence of IPDT, ITS and Ea on DS of the acetylation of dextran is also discussed. (author)

Gas chromatography/isotope ratio mass spectrometry: analysis of methanol, ethanol and acetic acid by direct injection of aqueous alcoholic and acetic acid samples.

Science.gov (United States)

Ai, Guomin; Sun, Tong; Dong, Xiuzhu

2014-08-15

Methanol, ethanol, and acetic acid are not easily extracted from aqueous samples and are susceptible to isotope fractionation in gas chromatography/isotope ratio mass spectrometry (GC/IRMS) analysis. Developing a direct dilution GC/IRMS method for aqueous samples, by adjusting the sample concentrations in common solvents to be similar to each other and using a fixed GC split ratio, is very convenient and important because any linearity effects caused by amount-dependent isotope fractionation can be avoided. The suitability of acetonitrile and acetone solvents for the GC/IRMS analysis of pure methanol, ethanol and acetic acid, and commercial liquor and vinegar samples was evaluated using n-hexane and water as control solvents. All the solvents including water were separated from the analyte on a HP-INNOWAX column and were diverted away from the combustion interface. The influence of liquor matrix on the ethanol GC/IRMS analyses was evaluated by adding pure ethanol to liquor samples. Acetonitrile and acetone gave similar δ(13) C values for pure ethanol and pure acetic acid to those obtained in water and n-hexane, and also gave similar δ(13) C values of ethanol in liquor and acetic acid in white vinegar to that obtained in water. For methanol analysis, acetonitrile and refined acetone gave similar δ(13) C values to that obtained in water, but n-hexane was not a suitable solvent. In addition, isotopic fractionation caused by solvent and solute interactions was observed. We recommend using acetonitrile for the GC/IRMS analysis of aqueous alcoholic samples, and acetone for the analysis of aqueous acetic acid samples. This direct dilution method can provide high accurate and precise GC/IRMS analysis of the relative changes in δ(13) C values of methanol, ethanol, and acetic acid. Copyright © 2014 John Wiley & Sons, Ltd.

Acetal-Linked Paclitaxel Polymeric Prodrug Based on Functionalized mPEG-PCL Diblock Polymer for pH-Triggered Drug Delivery

Directory of Open Access Journals (Sweden)

Yinglei Zhai

2017-12-01

Full Text Available The differences in micro-environment between cancer cells and the normal ones offer the possibility to develop stimuli-responsive drug-delivery systems for overcoming the drawbacks in the clinical use of anticancer drugs, such as paclitaxel, doxorubicin, and etc. Hence, we developed a novel endosomal pH-sensitive paclitaxel (PTX prodrug micelles based on functionalized poly(ethylene glycol-poly(ε-caprolactone (mPEG-PCL diblock polymer with an acid-cleavable acetal (Ace linkage (mPEG-PCL-Ace-PTX. The mPEG-PCL-Ace-PTX5 with a high drug content of 23.5 wt % was self-assembled in phosphate buffer (pH 7.4, 10 mM into nanosized micelles with an average diameter of 68.5 nm. The in vitro release studies demonstrated that mPEG-PCL-Ace-PTX5 micelles was highly pH-sensitive, in which 16.8%, 32.8%, and 48.2% of parent free PTX was released from mPEG-PCL-Ace-PTX5 micelles in 48 h at pH 7.4, 6.0, and 5.0, respectively. Thiazolyl Blue Tetrazolium Bromide (MTT assays suggested that the pH-sensitive PTX prodrug micelles displayed higher therapeutic efficacy against MCF-7 cells compared with free PTX. Therefore, the PTX prodrug micelles with acetal bond may offer a promising strategy for cancer therapy.

Clomazone selectivity in cotton seeds treated with dietholate and zinc acetate

Directory of Open Access Journals (Sweden)

Miriam Hiroko Inoue

2014-12-01

Full Text Available The objective of this study objective was to evaluate the selectivity of pre-emergence applications the herbicide clomazone cotton seeds treated with dietholate and zinc acetate. The 4 x 2 factorial arrangement was adopted (4 seed treatment methods and 2 clomazone dosages, distributed in a randomized block design with 4 repetitions. In treatments where dietholate and zinc acetate were applied, rates of 0.4 kg ha-1 and 8 ml per kg of seeds were used respectively. The clomazone rates used refer to 0.8 and 1.0 kg ha- 1. The cotton cultivar used was the Fiber Max 966 LL. Independent of treatment, all seeds were treated with tiametoxam insecticide and fludioxonil + metalaxyl-M fungicide at rates of 2.24 and 0.08 + 0.03 g per kg of seed, respectively, to control pests early and limit losses caused by pathogens in germination and seedling emergence. Dietholate and zinc acetate treatment had greater initial effect on cotton plants at 21, 30 and 45 days after application. In phytointoxication symptoms were observed for treatment with dietholate and zinc acetate during the evaluation periods. Seeds treated with dietholate, dietholate and zinc acetate or zinc acetate alone provided a higher number of bolls and seed cotton production compared to the control.

Sustainable bio-based materials: opportunities and challenges

NARCIS (Netherlands)

van der Meer, Yvonne

2017-01-01

Research in the area of bio-based materials aims to achieve breakthroughs in bio-based materials development. A novel way is presented to organise bio-based materials research with a value chain approach in which sustainability research is integrated in the research program. This research approach

Enzymatic Production of Glutathione by Bifunctional γ-Glutamylcysteine Synthetase/Glutathione Synthetase Coupled with In Vitro Acetate Kinase-Based ATP Generation.

Science.gov (United States)

Jiang, Yu; Tao, Rongsheng; Shen, Zhengquan; Sun, Liangdong; Zhu, Fuyun; Yang, Sheng

2016-12-01

Glutathione (γ-glutamyl-L-cysteinylglycine, GSH) is a pharmaceutical compound often used in food additives and the cosmetics industry. GSH can be produced biologically from L-glutamic acid, L-cysteine, and glycine through an enzymatic process traditionally involving two sequential adenosine triphosphate (ATP)-dependent reactions catalyzed by γ-glutamylcysteine synthetase (γ-GCS or GSHI, EC 6.3.2.2) and GSH synthetase (GS or GSHII, EC 6.3.2.3). Here, we report the enzymatic production of GSH by recombinant cell-free bifunctional γ-glutamylcysteine synthetase/glutathione synthetase (γ-GCS-GS or GshF) coupled with in vitro acetate kinase-based ATP generation. GSH production by an acetate kinase-integrated Escherichia coli Rosetta(DE3) mutant expressing Streptococcus thermophilus GshF reached 18.3 ± 0.1 g l -1 (59.5 ± 0.3 mM) within 3 h, with a molar yield of 0.75 ± 0.00 mol mol -1 added cysteine and a productivity of 6.1 ± 0.0 g l -1  h -1 . This is the highest GSH titer reported to date. This newly developed biocatalytic process offers a promising approach for meeting the industrial requirements for GSH production.

Isotope fractionation during the anaerobic consumption of acetate by methanogenic and sulfate-reducing microorganisms

Science.gov (United States)

Gövert, D.; Conrad, R.

2009-04-01

During the anaerobic degradation of organic matter in anoxic sediments and soils acetate is the most important substrate for the final step in production of CO2 and/or CH4. Sulfate-reducing bacteria (SRB) and methane-producing archaea both compete for the available acetate. Knowledge about the fractionation of 13C/12C of acetate carbon by these microbial groups is still limited. Therefore, we determined carbon isotope fractionation in different cultures of acetate-utilizing SRB (Desulfobacter postgatei, D. hydrogenophilus, Desulfobacca acetoxidans) and methanogens (Methanosarcina barkeri, M. acetivorans). Including literature values (e.g., Methanosaeta concilii), isotopic enrichment factors (epsilon) ranged between -35 and +2 permil, possibly involving equilibrium isotope effects besides kinetic isotope effects. The values of epsilon were dependent on the acetate-catabolic pathway of the particular microorganism, the methyl or carboxyl position of acetate, and the relative availability or limitation of the substrate acetate. Patterns of isotope fractionation in anoxic lake sediments and rice field soil seem to reflect the characteristics of the microorganisms actively involved in acetate catabolism. Hence, it might be possible using environmental isotopic information to determine the type of microbial metabolism converting acetate to CO2 and/or CH4.

Composite materials for thermal energy storage

Science.gov (United States)

Benson, D. K.; Burrows, R. W.; Shinton, Y. D.

1985-01-01

A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations are discussed. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

Composite materials for thermal energy storage

Science.gov (United States)

Benson, D.K.; Burrows, R.W.; Shinton, Y.D.

1985-01-04

A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

Micro-syntheses for the use of carbon 13 or carbon 14. Micro-preparations of methyl alcohol, methyl iodide, and sodium acetate labeled in the methyl group; Microsyntheses pour l'emploi de carbone 13 ou de carbone 14. Micropreparations d'alcool methylique, d'iodure de methyle et d'acetate de sodium marque sur le groupement methyle

Energy Technology Data Exchange (ETDEWEB)

Baret, C; Pichat, L

1951-11-01

Apparatus and technique are described in detail for (1) reduction of CO{sub 2} to CH{sub 3}OH with LiAlH{sub 4}, (2) conversion of the methanol to CH{sub 3}I by HI, (3) formation of the Mg Grignard reagent, and (4) addition of inactive CO{sub 2} to form CH{sub 3}COOH. All these operations have been carried out on 0.005 moles. Methyl-labeled Na acetate has been prepared in 67% yield based on the Ba{sup 14}CO{sub 3} used as starting material. (author) [French] Description detaillee d'une technique deja connue pour la reduction du gaz carbonique en alcool methylique par LiAlH{sub 4}. Conversion du methanol en iodure de methyle. Ce dernier transforme en reactif de Grigard, et carbonate, fournit de l'acide acetique. Toutes ces operations on ete effectuees sur 5 x 10{sup -3} moles. La methode a ete appliquee a la synthese d'acetate de sodium marque par le groupement methyle par {sup 14}C avec un rendement global de 67% base sur le carbonate de baryum radioactif mis en oeuvre. (auteurs)

{sup 1}H-NMR characterization of cellulose acetate obtained from sugarcane bagasse; Caracterizacao de acetato de celulose obtido a partir do bagaco de cana-de-acucar por {sup 1}H-RMN

Energy Technology Data Exchange (ETDEWEB)

Cerqueira, Daniel A., E-mail: daniel.cerqueira@ufba.b [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Ciencias Ambientais e Desenvolvimento Sustentavel; Rodrigues Filho, Guimes [Universidade Federal de Uberlandia (UFU), MG (Brazil). Inst. de Quimica; Carvalho, Rui de A. [Universidade de Coimbra (Portugal). Dept. de Bioquimica; Valente, Artur J.M. [Universidade de Coimbra (Portugal). Dept. de Quimica

2010-07-01

Cellulose from sugarcane bagasse was used for synthesizing cellulose acetate with different degrees of substitution, which were characterized by {sup 1}H-NMR through the relationship between the peak areas of the hydrogen atoms of the acetate groups (-(C=O)OCH{sub 3}) and the peaks of the hydrogen bonded to the carbon atoms of the glycosidic rings. Suppression of some signals was carried out in order to remove the residual water resonance in the materials and those related to impurities in cellulose triacetate as well. A deconvolution method for the computation of the degree of substitution of acetylation is proposed. The degrees of substitution for the cellulose samples were 2.94 and 2.60, in good agreement with those obtained by chemical determination through an acid-base titration. (author)

Future perspectives of resin-based dental materials.

Science.gov (United States)

Jandt, Klaus D; Sigusch, Bernd W

2009-08-01

This concise review and outlook paper gives a view of selected potential future developments in the area of resin-based biomaterials with an emphasis on dental composites. A selection of key publications (1 book, 35 scientific original publications and 1 website source) covering the areas nanotechnology, antimicrobial materials, stimuli responsive materials, self-repairing materials and materials for tissue engineering with direct or indirect relations and/or implications to resin-based dental materials is critically reviewed and discussed. Connections between these fields and their potential for resin-based dental materials are highlighted and put in perspective. The need to improve shrinkage properties and wear resistance is obvious for dental composites, and a vast number of attempts have been made to accomplish these aims. Future resin-based materials may be further improved in this respect if, for example nanotechnology is applied. Dental composites may, however, reach a completely new quality by utilizing new trends from materials science, such as introducing nanostructures, antimicrobial properties, stimuli responsive capabilities, the ability to promote tissue regeneration or repair of dental tissues if the composites were able to repair themselves. This paper shows selected potential future developments in the area of resin-based dental materials, gives basic and industrial researchers in dental materials science, and dental practitioners a glance into the potential future of these materials, and should stimulate discussion about needs and future developments in the area.

Degradation of acetic acid with sulfate radical generated by persulfate ions photolysis.

Science.gov (United States)

Criquet, Justine; Leitner, Nathalie Karpel Vel

2009-09-01

The photolysis of S(2)O(8)(2-) was studied for the removal of acetic acid in aqueous solution and compared with the H(2)O(2)/UV system. The SO(4)(-) radicals generated from the UV irradiation of S(2)O(8)(2-) ions yield a greater mineralization of acetic acid than the ()OH radicals. Acetic acid is oxidized by SO(4)(-) radicals without significant formation of intermediate by-products. Increasing system pH results in the formation of ()OH radicals from SO(4)(-) radicals. Maximum acetic acid degradation occurred at pH 5. The results suggest that above this pH, competitive reactions with the carbon mineralized inhibit the reaction of the solute with SO(4)(-) and also ()OH radicals. Scavenging effects of two naturally occurring ions were tested; in contrast to HCO(3)(-) ions, the presence of Cl(-) ions enhances the efficiency of the S(2)O(8)(2-)/UV process towards the acetate removal. It is attributed to the formation of the Cl() radical and its great reactivity towards acetate.

Acetate metabolism of Saccharomyces cerevisiae at different temperatures during lychee wine fermentation

Directory of Open Access Journals (Sweden)

Yu-hui Shang

2016-05-01

Full Text Available The yeast (Saccharomyces cerevisiae strain 2137 involved in lychee wine production was used to investigate acetate metabolism at different temperatures during lychee wine fermentation. Fermentation tests were conducted using lychee juice supplemented with acetic acid. The ability of yeast cells to metabolize acetic acid was stronger at 20 °C than at 25 °C or 30 °C. The addition of acetic acid suppressed the yeast cell growth at the tested temperatures. The viability was higher and the reactive oxygen species concentration was lower at 20 °C than at 30 °C; this result indicated that acid stress adaptation protects S. cerevisiae from acetic-acid-mediated programmed cell death. The acetic acid enhanced the thermal death of yeast at high temperatures. The fermentation temperature modified the metabolism of the yeasts and the activity of related enzymes during deacidification, because less acetaldehyde, less glycerol, more ethanol, more succinic acid and more malic acid were produced, with higher level of acetyl–CoA synthetase and isocitrate lyase activity, at 20 °C.

Acute effects of ethanol and acetate on glucose kinetics in normal subjects

International Nuclear Information System (INIS)

Yki-Jaervinen, H.; Koivisto, V.A.; Ylikahri, R.; Taskinen, M.R.

1988-01-01

The authors compared the effects of two ethanol doses on glucose kinetics and assessed the role of acetate as a mediator of ethanol-induced insulin resistance. Ten normal males were studied on four occasions, during which either a low or moderate ethanol, acetate, or saline dose was administered. Both ethanol doses similarly inhibited basal glucose production. The decrease in R a was matched by a comparable decrease in glucose utilization (R d ), resulting in maintenance of normoglycemia. During hyperinsulinemia glucose disposal was lower in the moderate than the low-dose ethanol or saline studies. During acetate infusion, the blood acetate level was comparable with those in the ethanol studies. Acetate had no effect on glucose kinetics. In conclusion, (1) in overnight fasted subjects, ethanol does not cause hypoglycemia because its inhibitory effect on R a is counterbalanced by equal inhibition of R d ; (2) basal R a and R d are maximally inhibited already by small ethanol doses, whereas inhibition of insulin-stimulated glucose disposal requires a moderate ethanol dose; and (3) acetate is not the mediator of ethanol-induced insulin resistance

Abiraterone Acetate: A Review in Metastatic Castration-Resistant Prostrate Cancer.

Science.gov (United States)

Scott, Lesley J

2017-09-01

Oral abiraterone acetate (Zytiga ® ) is a selective inhibitor of CYP17 and thereby inhibits androgen biosynthesis, with androgen signalling crucial in the progression from primary to metastatic prostate cancer (PC) and subsequently, in the development of metastatic castration-resistant PC (mCRPC). In large phase 3 trials and in the clinical practice setting, oral abiraterone acetate in combination with prednisone was an effective treatment and had an acceptable, manageable tolerability and safety profile in chemotherapy-naive and docetaxel-experienced men with mCRPC. In the pivotal global phase 3 trials, relative to placebo (+prednisone), abiraterone acetate (+prednisone) prolonged overall survival (OS) at data maturity (final analysis) and radiographic progression-free survival (rPFS) at all assessed timepoints. Given its efficacy in prolonging OS and its convenient once-daily oral regimen, in combination with prednisone, abiraterone acetate is an important first-line option for the treatment of mCRPC.

Analysis of acetal toilet fill valve supply line nut failure

Directory of Open Access Journals (Sweden)

Anthony Timpanaro

2017-10-01

Full Text Available In recent years, there has been a rise in the number of product liability cases involving the failure of toilet water supply line acetal plastic nuts. These nuts can fail in service, causing water leaks that result in significant property and financial losses. This study examines three possible failure modes of acetal plastic toilet water supply nuts. The three failure modes tested were all due to over load failure of the acetal nut and are as follows: (1 Overtightening of the supply line acetal nut, (2 Supply line lateral pull and, (3 Embrittled supply line lateral pull. Additionally, a “hand-tight” torque survey was conducted. The fracture surfaces and characteristics of these failure tests were examined with Stereo Microscopy and Scanning Electron Microscopy (SEM. The failure modes were compared and contrasted to provide guidance in determination of cause in these investigations.

Hydrolysis of Acetic Anhydride in a CSTR

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Veronica N. Coraci

2016-05-01

Full Text Available To find the optimal reactor volume and temperature for the hydrolysis of acetic anhydride at the lowest possible cost with a 90% conversion of acetic anhydride, a formula for the total cost of the reaction was created. Then, the first derivative was taken to find a value for the temperature. This value was then inputted into the second derivative of the equation to find the sign of the value which would indicate whether that point was a minima or maxima value. The minima value would then be the lowest total cost for the optimum reaction to take place.

Micro-syntheses for the use of carbon 13 or carbon 14. Micro-preparations of methyl alcohol, methyl iodide, and sodium acetate labeled in the methyl group

International Nuclear Information System (INIS)

Baret, C.; Pichat, L.

1951-11-01

Apparatus and technique are described in detail for (1) reduction of CO 2 to CH 3 OH with LiAlH 4 , (2) conversion of the methanol to CH 3 I by HI, (3) formation of the Mg Grignard reagent, and (4) addition of inactive CO 2 to form CH 3 COOH. All these operations have been carried out on 0.005 moles. Methyl-labeled Na acetate has been prepared in 67% yield based on the Ba 14 CO 3 used as starting material. (author) [fr

Effect of ionizing radiation on physicochemical and mechanical properties of commercial multilayer coextruded flexible plastics packaging materials

Science.gov (United States)

Goulas, Antonios E.; Riganakos, Kyriakos A.; Kontominas, Michael G.

2003-12-01

The effect of gamma radiation (doses: 5, 10 and 30 kGy) on mechanical properties, gas and water vapour permeability and overall migration values into distilled water, 3% aqueous acetic acid and iso-octane was studied for a series of commercial multilayer flexible packaging materials based on coextruded polypropylene (PP), ethylene vinyl alcohol (EVOH), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), polyamide (PA) and Ionomer. The results showed that radiation doses of 5 and 10 kGy induced no statistically significant differences ( p>0.05) in all polymer properties examined. A dose of 30 kGy induced differences ( pfilms. In addition, the same dose induced differences ( pfilms into 3% acetic acid and iso-octane and in the overall migration from PP/EVOH/LDPE-LLDPE into iso-octane. Differences recorded, are discussed in relation to food irradiation applications of respective packaging materials.

New Cork-Based Materials and Applications

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Luís Gil

2015-02-01

Full Text Available This review work is an update of a previous work reporting the new cork based materials and new applications of cork based materials. Cork is a material which has been used for multiple applications. The most known uses of cork are in stoppers (natural and agglomerated cork for alcoholic beverages, classic floor covering with composite cork tiles (made by the binding of cork particles with different binders, and thermal/acoustic/vibration insulation with expanded corkboard in buildings and some other industrial fields. Many recent developments have been made leading to new cork based materials. Most of these newly developed cork materials are not yet on the market, but they represent new possibilities for engineers, architects, designers and other professionals which must be known and considered, potentially leading to their industrialization. This paper is a review covering the last five years of innovative cork materials and applications also mentioning previous work not reported before.

New Cork-Based Materials and Applications

Science.gov (United States)

Gil, Luís

2015-01-01

This review work is an update of a previous work reporting the new cork based materials and new applications of cork based materials. Cork is a material which has been used for multiple applications. The most known uses of cork are in stoppers (natural and agglomerated cork) for alcoholic beverages, classic floor covering with composite cork tiles (made by the binding of cork particles with different binders), and thermal/acoustic/vibration insulation with expanded corkboard in buildings and some other industrial fields. Many recent developments have been made leading to new cork based materials. Most of these newly developed cork materials are not yet on the market, but they represent new possibilities for engineers, architects, designers and other professionals which must be known and considered, potentially leading to their industrialization. This paper is a review covering the last five years of innovative cork materials and applications also mentioning previous work not reported before. PMID:28787962

New Cork-Based Materials and Applications.

Science.gov (United States)

Gil, Luís

2015-02-10

This review work is an update of a previous work reporting the new cork based materials and new applications of cork based materials. Cork is a material which has been used for multiple applications. The most known uses of cork are in stoppers (natural and agglomerated cork) for alcoholic beverages, classic floor covering with composite cork tiles (made by the binding of cork particles with different binders), and thermal/acoustic/vibration insulation with expanded corkboard in buildings and some other industrial fields. Many recent developments have been made leading to new cork based materials. Most of these newly developed cork materials are not yet on the market, but they represent new possibilities for engineers, architects, designers and other professionals which must be known and considered, potentially leading to their industrialization. This paper is a review covering the last five years of innovative cork materials and applications also mentioning previous work not reported before.

Highly Concentrated Acetic Acid Poisoning: 400 Cases Reviewed

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Konstantin Brusin

2012-12-01

Full Text Available Background: Caustic substance ingestion is known for causing a wide array of gastrointestinal and systemic complications. In Russia, ingestion of acetic acid is a major problem which annually affects 11.2 per 100,000 individuals. The objective of this study was to report and analyze main complications and outcomes of patients with 70% concentrated acetic acid poisoning. Methods: This was a retrospective study of patients with acetic acid ingestion who were treated at Sverdlovsk Regional Poisoning Treatment Center during 2006 to 2012. GI mucosal injury of each patient was assessed with endoscopy according to Zargar’s scale. Data analysis was performed to analyze the predictors of stricture formation and mortality. Results: A total of 400 patients with median age of 47 yr were included. GI injury grade I was found in 66 cases (16.5%, IIa in 117 (29.3%, IIb in 120 (30%, IIIa in 27 (16.7% and IIIb in 70 (17.5%. 11% of patients developed strictures and overall mortality rate was 21%. Main complications were hemolysis (55%, renal injury (35%, pneumonia (27% and bleeding during the first 3 days (27%. Predictors of mortality were age 60 to 79 years, grade IIIa and IIIb of GI injury, pneumonia, stages “I”, “F” and “L” of kidney damage according to the RIFLE scale and administration of prednisolone. Predictors of stricture formation were ingestion of over 100 mL of acetic acid and grade IIb and IIIa of GI injury. Conclusion: Highly concentrated acetic acid is still frequently ingested in Russia with a high mortality rate. Patients with higher grades of GI injury, pneumonia, renal injury and higher amount of acid ingested should be more carefully monitored as they are more susceptible to develop fatal consequences.          

Bioelectrochemical Ethanol Production through Mediated Acetate Reduction by Mixed Cultures

NARCIS (Netherlands)

Steinbusch, K.J.J.; Hamelers, H.V.M.; Schaap, J.D.; Kampman, C.; Buisman, C.J.N.

2010-01-01

Biological acetate reduction with hydrogen is a potential method to convert wet biomass waste into ethanol. Since the ethanol concentration and reaction rates are low, this research studies the feasibility of using an electrode, in stead of hydrogen, as an electron donor for biological acetate

Poly(vinyl acetate-Based Block Copolymer/Clay Nanocomposites Prepared by In Situ Atom Transfer Radical Polymerization

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M.A. Semsarzadeh

2009-12-01

Full Text Available Atom transfer radical polymerization of styrene (St and methyl methacrylate (MMA was performed at 90oC in the absence and presence of nanoclay (Cloisite 30B. Trichloromethyl-terminated poly(vinyl acetate telomerand CuCl/ PMDETA were used as a macroinitiator and catalyst system, respectively. The experimental results showed that the atom transfer radical polymerization of St and MMA in the absence or presence of nanoclay proceeds via a controlled/living mode. It was observed that nanoclay significantly enhances the homopolymerization rate of MMA, which was attributed to the activated conjugated C=C bond of MMA monomer via interaction between the carbonyl group of MMA monomer and the hydroxyl moiety (Al-O-H of nanoclay as well as the effect of nanoclay on the dynamic equilibrium between the active (macro radicals and dormant species.Homopolymerization rate of St (a non-coordinative monomer with nanoclay decreased slightly in the presence of nanoclay. This could be explained by insertion of a portion of macroinitiator into the clay galleries, where no sufficient St monomer exists due to the low compatibility or interaction of St monomer with nanoclay to react with the macroinitiator. The results obtained from XRD, TEM and TGA analyses were fully in agreement with the kinetic data. Structure of the poly(vinyl acetate-bpolystyrene nanocomposite was found to be a combination of stacking layers and exfoliated structures while poly(vinyl acetate-b-poly(methyl methacryale nanocomposite had an exfoliated structure. This difference in the structure of nanocomposites was attributed to the different capability of the monomers (styrene and methyl methacrylate to react with the hydroxyl moiety (Al-O-H of nanoclay.

Sensor-based material tagging system

International Nuclear Information System (INIS)

Vercellotti, L.C.; Cox, R.W.; Ravas, R.J.; Schlotterer, J.C.

1991-01-01

Electronic identification tags are being developed for tracking material and personnel. In applying electronic identification tags to radioactive materials safeguards, it is important to measure attributes of the material to ensure that the tag remains with the material. The addition of a microcontroller with an on-board analog-to-digital converter to an electronic identification tag application-specific integrated-circuit has been demonstrated as means to provide the tag with sensor data. Each tag is assembled into a housing, which serves as a scale for measuring the weight of a paint-can-sized container and its contents. Temperature rise of the can above ambient is also measured, and a piezoelectric detector detects disturbances and immediately puts the tag into its alarm and beacon mode. Radiation measurement was also considered, but the background from nearby containers was found to be excessive. The sensor-based tagging system allows tracking of the material in cans as it is stored in vaults or is moved through the manufacturing process. The paper presents details of the sensor-based material tagging system and describes a demonstration system

Density, dynamic viscosity, and derived properties of binary mixtures of methanol or ethanol with water, ethyl acetate, and methyl acetate at T (293.15, 298.15, and 303.15) K

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, Begona; Calvar, Noelia; Gomez, Elena [Chemical Engineering Department, University of Vigo, 36200 Vigo (Spain); Dominguez, Angeles [Chemical Engineering Department, University of Vigo, 36200 Vigo (Spain)], E-mail: admguez@uvigo.es

2007-12-15

Densities and dynamic viscosities for methanol or ethanol with water, ethyl acetate, and methyl acetate at several temperatures T = (293.15, 298.15, and 303.15) K have been measured over the whole composition range and 0.1 MPa, along with the properties of the pure components. Excess molar volumes, viscosity deviations, and excess free energy of activation for the binary systems at the above-mentioned temperatures, were calculated and fitted to the Redlich-Kister equation to determine the fitting parameters and the root-mean-square deviations. UNIQUAC equation was used to correlate the experimental viscosity data. The UNIFAC-VISCO method and ASOG-VISCO method, based on contribution groups, were used to predict the dynamic viscosities of the binary mixtures.

Density, dynamic viscosity, and derived properties of binary mixtures of methanol or ethanol with water, ethyl acetate, and methyl acetate at T (293.15, 298.15, and 303.15) K

International Nuclear Information System (INIS)

Gonzalez, Begona; Calvar, Noelia; Gomez, Elena; Dominguez, Angeles

2007-01-01

Densities and dynamic viscosities for methanol or ethanol with water, ethyl acetate, and methyl acetate at several temperatures T = (293.15, 298.15, and 303.15) K have been measured over the whole composition range and 0.1 MPa, along with the properties of the pure components. Excess molar volumes, viscosity deviations, and excess free energy of activation for the binary systems at the above-mentioned temperatures, were calculated and fitted to the Redlich-Kister equation to determine the fitting parameters and the root-mean-square deviations. UNIQUAC equation was used to correlate the experimental viscosity data. The UNIFAC-VISCO method and ASOG-VISCO method, based on contribution groups, were used to predict the dynamic viscosities of the binary mixtures

Synthesis of polymer electrolyte membranes from cellulose acetate/poly(ethylene oxide)/LiClO{sub 4} for lithium ion battery application

Energy Technology Data Exchange (ETDEWEB)

Nurhadini,, E-mail: nur-chem@yahoo.co.id; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Division, Faculty of Mathematics and Natural Sciences, Institiut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132 (Indonesia)

2015-09-30

This study was conducted to determine the effect of cellulose acetate on poly(ethylene oxide)-LiClO{sub 4} membranes as the polymer electrolyte. Cellulose acetate is used as an additive to increase ionic conductivity and mechanical property of polymer electrolyte membranes. The increase the percentage of cellulose acetate in membranes do not directly effect on the ionic conductivity, and the highest ionic conductivity of membranes about 5,7 × 10{sup −4} S/cm was observed in SA/PEO/LiClO{sub 4} membrane with cellulose ratio of 10-25% (w/w). Cellulose acetate in membranes increases mechanical strength of polymer electrolyte membranes. Based on TGA analysis, this polymer electrolyte thermally is stable until 270 °C. The polymer electrolyte membrane prepared by blending the cellulose acetate, poly(ethylene oxide), and lithium chlorate could be potentially used as a polymer electrolyte for lithium ion battery application.

Bioelectrochemical ethanol production through mediated acetate reduction by mixed cultures.

Science.gov (United States)

Steinbusch, Kirsten J J; Hamelers, Hubertus V M; Schaap, Joris D; Kampman, Christel; Buisman, Cees J N

2010-01-01

Biological acetate reduction with hydrogen is a potential method to convert wet biomass waste into ethanol. Since the ethanol concentration and reaction rates are low, this research studies the feasibility of using an electrode, in stead of hydrogen, as an electron donor for biological acetate reduction in conjunction of an electron mediator. Initially, the effect of three selected mediators on metabolic flows during acetate reduction with hydrogen was explored; subsequently, the best performing mediator was used in a bioelectrochemical system to stimulate acetate reduction at the cathode with mixed cultures at an applied cathode potential of -550 mV. In the batch test, methyl viologen (MV) was found to accelerate ethanol production 6-fold and increased ethanol concentration 2-fold to 13.5 +/- 0.7 mM compared to the control. Additionally, MV inhibited n-butyrate and methane formation, resulting in high ethanol production efficiency (74.6 +/- 6%). In the bioelectrochemical system, MV addition to an inoculated cathode led directly to ethanol production (1.82 mM). Hydrogen was coproduced at the cathode (0.0035 Nm(3) hydrogen m(-2) d(-1)), so it remained unclear whether acetate was reduced to ethanol by electrons supplied by the mediator or by hydrogen. As MV reacted irreversibly at the cathode, ethanol production stopped after 5 days.

On the materials issues for pefc applications

Directory of Open Access Journals (Sweden)

Savadogo Oumarou

2004-01-01

Full Text Available Current limitations related to the development of effective, durable and reliable MEA components for PEFC applications are addressed. Advancements made in the development of materials (catalysts, high temperature membranes, bipolar plates, etc. for PEFC are shown. The effect of the catalyst on PEFC performances based on cells fed by hydrogen, direct methanol, direct propane, or direct acetal fuels are presented. The progress in cell performance and cathode research are discussed. Perspectives related to CO tolerance anodes are indicated. The effect of the membranes on the cell performance are shown and parameters which may help the development of appropriate membranes depending on the fuel are suggested. Openings for the future in materials processing and development for PEFC mass production are discussed. The development of New Materials is the key factor to meet those requirements. The aim of this paper is to present challenges related to the development of new materials for PEFC applications and perspectives related to components cost issues are discussed.

Acetic acid bacteria: A group of bacteria with versatile biotechnological applications.

Science.gov (United States)

Saichana, Natsaran; Matsushita, Kazunobu; Adachi, Osao; Frébort, Ivo; Frebortova, Jitka

2015-11-01

Acetic acid bacteria are gram-negative obligate aerobic bacteria assigned to the family Acetobacteraceae of Alphaproteobacteria. They are members of the genera Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Neokomagataea, and Komagataeibacter. Many strains of Acetobacter and Komagataeibacter have been known to possess high acetic acid fermentation ability as well as the acetic acid and ethanol resistance, which are considered to be useful features for industrial production of acetic acid and vinegar, the commercial product. On the other hand, Gluconobacter strains have the ability to perform oxidative fermentation of various sugars, sugar alcohols, and sugar acids leading to the formation of several valuable products. Thermotolerant strains of acetic acid bacteria were isolated in order to serve as the new strains of choice for industrial fermentations, in which the cooling costs for maintaining optimum growth and production temperature in the fermentation vessels could be significantly reduced. Genetic modifications by adaptation and genetic engineering were also applied to improve their properties, such as productivity and heat resistance. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of Pb-acetate on Testicle Weight and Volume of Mice

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Israhnanto Isradji

2011-12-01

Design and Method: Eighty male mice placed in individual cages according to the group. Food and drink provided ad libitum. The treatment of male mice given for 6 weeks. Treatment with 0.2 ml distilled water to PI, P II were given a solution of 400 ppm Pb acetate total of 0.2 ml, P III was given a solution of 1000 ppm Pb acetate as many as 0.2 ml, and P IV were given a solution of 2000 ppm Pb acetate total of 0,2 ml by using a gastric sonde, every morning once a day for 42 days. At week 7, mice were surgery to take the testis. Testicular volume was measured and weighed. Data were analyzed by ANOVA, hypothesis is accepted when p 0.05, testis weight obtained by ANOVA test probability of 0.216 (> 0.05, mean Pb -acetate had no effect on testis weight and volume. Conclusion: Pb-acetate had no effect on testis weight and volume (Sains Medika, 3(2:150-156.

Formation of acetals under rhodium-catalyzed hydroformylation conditions in alcohols

NARCIS (Netherlands)

Diebolt, O.H.; Müller, C.; Cruzeuil, C.; Vogt, D.

2012-01-01

Hydroformylation of terminal alkenes in alcohol solvents leads to the selective formation of the corresponding acetals. The Xantphos ligand gave the best results as well as acetal selectivities higher than 99% and linear/branched ratios of up to 52 were obtained. The scope of the reaction was

Tungsten - Yttrium Based Nuclear Structural Materials

Science.gov (United States)

Ramana, Chintalapalle; Chessa, Jack; Martinenz, Gustavo

2013-04-01

The challenging problem currently facing the nuclear science community in this 21st century is design and development of novel structural materials, which will have an impact on the next-generation nuclear reactors. The materials available at present include reduced activation ferritic/martensitic steels, dispersion strengthened reduced activation ferritic steels, and vanadium- or tungsten-based alloys. These materials exhibit one or more specific problems, which are either intrinsic or caused by reactors. This work is focussed towards tungsten-yttrium (W-Y) based alloys and oxide ceramics, which can be utilized in nuclear applications. The goal is to derive a fundamental scientific understanding of W-Y-based materials. In collaboration with University of Califonia -- Davis, the project is designated to demonstrate the W-Y based alloys, ceramics and composites with enhanced physical, mechanical, thermo-chemical properties and higher radiation resistance. Efforts are focussed on understanding the microstructure, manipulating materials behavior under charged-particle and neutron irradiation, and create a knowledge database of defects, elemental diffusion/segregation, and defect trapping along grain boundaries and interfaces. Preliminary results will be discussed.

A molecular molybdenum–schiff base electro-catalyst for generating hydrogen from acetic acid or water

International Nuclear Information System (INIS)

Cao, Jie-Ping; Fang, Ting; Zhou, Ling-Ling; Fu, Ling-Zhi; Zhan, Shuzhong

2014-01-01

Highlights: • The reaction of ligand, H 2 L and MoCl 5 gives a Mo(VI) complex [MoL(O) 2 ] 1. • Complex 1 is capable of catalyzing hydrogen evolution from acetic acid and water. • TOF reaches a maximum of 68 (DMF) and 356 (buffer, pH 6) moles/h, respectively. • Sustained proton reduction catalysis occurs over a 69 h period and no decomposition of 1. - ABSTRACT: The reaction of 2-pyridylamino-N,N-bis(2-methylene-4-ethyl-6-tert-butylphenol) (H 2 L) and MoCl 5 gives a molybdenum(VI) complex [MoL(O) 2 ] 1, a new molecular electrocatalyst, which has been determined by X-ray crystallography. Electrochemical studies show that complex 1 can catalyze hydrogen evolution from acetic acid or aqueous buffer. Turnover frequency (TOF) reaches a maximum of 68 (in N,N-Dimethylformamide (DMF)) and 356 (in buffer, pH 6.0) moles of hydrogen per mole of catalyst per hour, respectively. Sustained proton reduction catalysis occurs at glassy carbon (GC) electrode to give H 2 over a 69 h electrolysis period and no observable decomposition of the catalyst

The effective reaction of 2-chloro-3-formylquinoline and acetic acid ...

African Journals Online (AJOL)

formylquinolines in a single step by treating with sodium acetate and acetic acid under microwave irradiation. The structures of the compounds have been established by IR, NMR and mass spectral data. Unexpectedly ...

Nanocellulose based polymer composite for acoustical materials

Science.gov (United States)

Farid, Mohammad; Purniawan, Agung; Susanti, Diah; Priyono, Slamet; Ardhyananta, Hosta; Rahmasita, Mutia E.

2018-04-01

Natural fibers are biodegradable materials that are innovatively and widely used for composite reinforcement in automotive components. Nanocellulose derived from natural fibers oil palm empty bunches have properties that are remarkable for use as a composite reinforcement. However, there have not been many investigations related to the use of nanocellulose-based composites for wideband sound absorption materials. The specimens of nanocellulose-based polyester composite were prepared using a spray method. An impedance tube method was used to measure the sound absorption coefficient of this composite material. To reveal the characteristics of the nanocellulose-based polyester composite material, SEM (scanning electron microscope), TEM (Transmission Electron Microscope), FTIR (Fourier Transform Infra Red), TGA (Thermogravimetric Analysis), and density tests were performed. Sound absorption test results showed the average value of sound absorption coefficient of 0.36 to 0,46 for frequency between 500 and 4000 Hz indicating that this nanocellulose-based polyester composite materials had a tendency to wideband sound absorption materials and potentially used as automotive interior materials.

Methanogenic archaea and sulfate reducing bacteria co-cultured on acetate: teamwork or coexistence?

NARCIS (Netherlands)

Ozuolmez, D.; Na, H.; Lever, M.A.; Kjeldsen, K.U.; Jørgensen, B.B.; Plugge, C.M.

2015-01-01

Acetate is a major product of fermentation processes and an important substrate for sulfate reducing bacteria and methanogenic archaea. Most studies on acetate catabolism by sulfate reducers and methanogens have used pure cultures. Less is known about acetate conversion by mixed pure cultures and

Effect of various solvents on the viscosity-average molecular weight of poly (vinyl acetate)

International Nuclear Information System (INIS)

Rehman, W.U.; But, M.A.; Chughtai, A.; Jamil, T.; Sattar, A.

2006-01-01

Solution polymerization of Vinyl Acetate was carried out in various solvents (benzene, toluene, ethyl acetate, acetonitrile). Dilute solution viscometry was used to determine the viscosity-average molecular weight of the resulting Poly (Vinyl Acetate) (PV Ac) in each case. The viscosity-average molecular weight (M,J of PVAc was found to increase in the order benzene < toluene < ethyl acetate < acetonitrile, It was concluded that under the same reaction conditions (polymerization time, initiator quantity, solvent/monomer ratio, temperature), acetonitrile served as the best solvent for solution. polymerization of Vinyl Acetate monomer. (author)

Comparative pharmacokinetic study of dosage forms with morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate

Directory of Open Access Journals (Sweden)

I. V. Bushueva

2014-12-01

Full Text Available Using mathematical models of income distribution and excretion of drugs greatly enhances the interpretation of the results of biopharmaceutical research. Pharmacokinetic modeling makes it possible to quantify the biological assessment of pharmaceutical factors, opens the possibility of a science-based regulation of the kinetics of substances introduced through targeted changesof pharmaceutical factors. Results of the study of kinetic models are used to solve some practical problems associated with pharmacological and clinical trials of medicines. Morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate is new organic compound from the 1,2,4-triazole group obtained at the Department of Inorganic Chemistry, Zaporozhye State Medical University. The substance has antioxidant and anti-ischemic action, low toxicity. Aim of this work is to study the kinetics of absorption of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate developed formulations. MATERIALS AND METHODS Pharmacokinetic studies of oral and rectal dosage forms of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate was performed on Chinchilla rabbits weighing an average of 2.5 kg, divided into three groups. The third group for comparison was administered a 1% injectable solution of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate intravenously. Substance dose was 0.1 g and 0.5 g per kg of animal body weight, which were administered once. Sampling from the auricular vein of the rabbits was performed at 5, 10, 15, 30, 45, 60, 75, 90, 120, 150 and 180 minutes after oral administration and rectal dosage forms of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate and after 3, 5, 10, 15, 20, 30, 40, 50 and 60 minutes after intravenous injection. Morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate concentration in serum was adjusted spectrophotometrically. Results.Morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio

Using bio-based polymers for curing cement-based materials

NARCIS (Netherlands)

Zlopasa, J.; Koenders, E.A.B.; Picken, S.J.

2014-01-01

Curing is the process of controlling the rate and extent of moisture loss from the surface of cement based materials. It is the final stage in the production of cement-based materials and it is the essential part for achieving continuous hydration of cement, while avoiding cracking due to drying

Anaerobic biodegradation of cellulosic material: Batch experiments and modelling based on isotopic data and focusing on aceticlastic and non-aceticlastic methanogenesis

International Nuclear Information System (INIS)

Qu, X.; Vavilin, V.A.; Mazeas, L.; Lemunier, M.; Duquennoi, C.; He, P.-J.; Bouchez, T.

2009-01-01

Utilizing stable carbon isotope data to account for aceticlastic and non-aceticlastic pathways of methane generation, a model was created to describe laboratory batch anaerobic decomposition of cellulosic materials (office paper and cardboard). The total organic and inorganic carbon concentrations, methane production volume, and methane and CO 2 partial pressure values were used for the model calibration and validation. According to the fluorescent in situ hybridization observations, three groups of methanogens including strictly hydrogenotrophic methanogens, strictly aceticlastic methanogens (Methanosaeta sp.) and Methanosarcina sp., consuming both acetate and H 2 /H 2 CO 3 as well as acetate-oxidizing syntrophs, were considered. It was shown that temporary inhibition of aceticlastic methanogens by non-ionized volatile fatty acids or acidic pH was responsible for two-step methane production from office paper at 35 o C where during the first and second steps methane was generated mostly from H 2 /H 2 CO 3 and acetate, respectively. Water saturated and unsaturated cases were tested. According to the model, at the intermediate moisture (150%), much lower methane production occurred because of full-time inhibition of aceticlastic methanogens. At the lowest moisture, methane production was very low because most likely hydrolysis was seriously inhibited. Simulations showed that during cardboard and office paper biodegradation at 55 o C, non-aceticlastic syntrophic oxidation by acetate-oxidizing syntrophs and hydrogenotrophic methanogens were the dominant methanogenic pathways.

Selection of nutrient used in biogenic healing agent for cementitious materials

Science.gov (United States)

Tziviloglou, Eirini; Wiktor, Virginie; Jonkers, Henk M.; Schlangen, Erik

2017-06-01

Biogenic self-healing cementitious materials target on the closure of micro-cracks with precipitated inorganic minerals originating from bacterial metabolic activity. Dormant bacterial spores and organic mineral compounds often constitute a biogenic healing agent. The current paper focuses on the investigation of the most appropriate organic carbon source to be used as component of a biogenic healing agent. It is of great importance to use an appropriate organic source, since it will firstly ensure an optimal bacterial performance in terms of metabolic activity, while it should secondly affect the least the properties of the cementitious matrix. The selection is made among three different organic compounds, namely calcium lactate, calcium acetate and sodium gluconate. The methodology that was used for the research was based on continuous and non-continuous oxygen consumption measurements of washed bacterial cultures and on compressive strength tests on mortar cubes. The oxygen consumption investigation revealed a preference for calcium lactate and acetate, but an indifferent behaviour for sodium gluconate. The compressive strength on mortar cubes with different amounts of either calcium lactate or acetate (up to 2.24% per cement weight) was not or it was positively affected when the compounds were dissolved in the mixing water. In fact, for calcium lactate the increase in compressive strength reached 8%, while for calcium acetate the maximum strength increase was 13.4%.

Acetate repression of methane oxidation by supplemental Methylocella silvestris in a peat soil microcosm.

Science.gov (United States)

Rahman, M Tanvir; Crombie, Andrew; Moussard, Hélène; Chen, Yin; Murrell, J Colin

2011-06-01

Methylocella spp. are facultative methanotrophs that grow on methane and multicarbon substrates, such as acetate. Acetate represses transcription of methane monooxygenase of Methylocella silvestris in laboratory culture. DNA stable-isotope probing (DNA-SIP) using (13)C-methane and (12)C-acetate, carried out with Methylocella-spiked peat soil, showed that acetate also repressed methane oxidation by Methylocella in environmental samples.

Investigation of acetic acid-catalyzed hydrothermal pretreatment on corn stover

DEFF Research Database (Denmark)

Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

2010-01-01

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...

modelling and simulation of the batch hydrolysis of acetic ing

African Journals Online (AJOL)

eobe

The kinetic modelling of the batch synthesis of acetic acid from acetic. The kinetic modelling of ... integral method of analysis to determine the kinetic parameters .... Equation (5) is applied to all the components ... In common chemical engineering terminology, the degree of ..... of Physical Organic Chemistry, Vol. 25, Number ...

Potentiometric investigations of (acid+base) equilibria in (n-butylamine+acetic acid) systems in binary (acetone+cyclohexane) solvent mixtures

International Nuclear Information System (INIS)

Czaja, MaIgorzata; Kozak, Anna; Makowski, Mariusz; Chmurzynski, Lech

2005-01-01

By using the potentiometric titration method, standard equilibrium constants have been determined of acid dissociation of molecular acid, K a (HA), cationic acid, K a (BH + ), of anionic and cationic homoconjugation, K AHA - andK BHB + , respectively, and of molecular heteroconjugation, K AHB (K BHA ), in (acid+base) systems without proton transfer consisting of n-butylamine and acetic acid in binary (acetone+cyclohexane) solvent mixtures. The results have shown that both the pK a (HA) and pK a (BH + ), as well as lgK AHA - values change non-linearly as a function of composition of the solvent mixture. On the other hand, standard molecular heteroconjugation constants without proton transfer do not depend on the cyclohexane content in the mixture, i.e. on solvent polarity

[Physiological response to acetic acid stress of Acetobacter pasteuranus during vinegar fermentation].

Science.gov (United States)

Qi, Zhengliang; Yang, Hailin; Xia, Xiaole; Wang, Wu; Leng, Yunwei; Yu, Xiaobin; Quan, Wu

2014-03-04

The aim of the study is to propose a dynamic acetic acid resistance mechanism through analysis on response of cellular morphology, physiology and metabolism of A. pasteurianus CICIM B7003 during vinegar fermentation. Vinegar fermentation was carried out in a Frings 9 L acetator by strain B7003 and cultures were sampled at different cellular growth phases. Simultaneously, percentage of capsular polysaccharide versus dry cells weight, ratio of unsaturated fatty acids to saturated fatty acids, transcription of acetic acid resistance genes, activity of alcohol respiratory chain enzymes and ATPase were detected for these samples to assay the responses of bacterial morphology, physiology and metabolism. When acetic acid was existed, no obvious capsular polysaccharide was secreted by cells. As vinegar fermentation proceeding, percentage of capsular polysaccharide versus dry cells weight was reduced from 2.5% to 0.89%. Ratio of unsaturated fatty acids to saturated fatty acids was increased obviously which can improve membrane fluidity. Also transcription level of acetic acid resistance genes was promoted. Interestingly, activity of alcohol respiratory chain and ATPase was not inhibited but promoted obviously with acetic acid accumulation which could provide enough energy for acetic acid resistance mechanism. On the basis of the results obtained from the experiment, A. pasteurianus CICIM B7003 relies mainly on the cooperation of changes of extracellular capsular polysaccharide and membrane fatty acids, activation of acid resistance genes transcription, enhancement of activity of alcohol respiratory chain and rapid energy production to tolerate acidic environment.

Secondary deuterium isotope effects in the hydrolysis of some acetals

International Nuclear Information System (INIS)

Paterson, R.V.

Secondary α-deuterium kinetic isotope effects have been determined in the hydrolyses of some acetals. Benzaldehyde dimethyl acetal and 2-phenyl-1,3-dioxolan show isotope effects in agreement with an A1 mechanism. 2-Phenyl-4,4,5,5-tetramethyl-1,3-dioxolan, which has been shown to undergo hydrolysis by an A2 type mechanism, has an isotope effect in agreement with participation by water in the transition state. Hydrolysis of benzylidene norbornanediols, although complicated by isomerisation, has an isotope effect in agreement with an A2 mechanism. Kinetic isotope effects in acetals which have a neighbouring carboxyl group have also been determined. Hydrolysis of 2-carboxybenzaldehyde dimethyl acetal in aqueous and 82% w/w dioxan-water buffers has isotope effects in agreement with a large degree of carbonium ion character in the transition state. Anderson and Capon proposed nucleophilic participation in the hydrolysis of this acetal in 82% dioxan-water. The isotope effect determined in this study is not in agreement with this finding. Hydrolysis of 2-(2'-carboxyphenyl)-4,4,5,5-tetramethyl-1,3-dioxolan shows an isotope effect larger than the corresponding dioxolan without the carboxyl group in agreement with some carbonium ion character in the transition state. A new synthesis of a deuterated aldehyde is described which might be general for aldehydes which will not form benzoins readily. (author)

LDEF materials special investigation group's data bases

Science.gov (United States)

Strickland, John W.; Funk, Joan G.; Davis, John M.

1993-01-01

The Long Duration Exposure Facility (LDEF) was composed of and contained a wide array of materials, representing the largest collection of materials flown for space exposure and returned for ground-based analyses to date. The results and implications of the data from these materials are the foundation on which future space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been tasked with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the space user community in an easily accessed, user-friendly form. The format and content of the data bases developed or being developed to accomplish this task are discussed. The hardware and software requirements for each of the three data bases are discussed along with current availability of the data bases.

Cellulose acetate electrospun nanofibrous membrane: fabrication ...

Indian Academy of Sciences (India)

337–343. c Indian Academy of Sciences. ... 1Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81300 Johor, Malaysia ... concentrations were prepared by dissolving the polymer in a mixture of acetic acid/acetone ...

Supramolecular fluorene based materials

OpenAIRE

Abbel, R.J.

2008-01-01

This thesis describes the use of noncovalent interactions in order to manipulate and control the self-assembly and morphology of electroactive fluorene-based materials. The supramolecular arrangement of p-conjugated polymers and oligomers can strongly influence their electronic and photophysical properties. Therefore, a detailed understanding of such organisation processes is essential for the optimisation of the performance of these materials as applied in optoelectronic devices. In order to...

Surface grafting of a dense and rigid coordination polymer based on tri-para-carboxy-polychlorotriphenylmethyl radical and copper acetate

KAUST Repository

Mugnaini, Veró nica; Paradinas, Markos; Shekhah, Osama; Roques, Nans; Ocal, Carmen; Wö ll, Christof H.; Veciana, Jaume

2013-01-01

The step-by-step method is here presented as suitable to anchor on appropriately functionalized gold surfaces a metal-organic coordination polymer based on a non-planar trigonal tri-para-carboxy-polychlorotriphenylmethyl radical derivative and copper acetate. The structural characteristics of the grafted coordination polymer are derived during the step-wise growth from the real time changes in refractive index and oscillation frequency. The film thickness, as measured by scanning force microscopy, combined with the mass uptake value from the quartz crystal microbalance, are used to estimate an average density of the grafted metal-organic coordination polymer that suggests the formation of a dense and rather rigid thin film. This journal is © 2013 The Royal Society of Chemistry.

Synthese und Charakterisierung wasserfreier Seltenerdmetall-Nitrate, -Acetate und -Oxyacetate

OpenAIRE

Heinrichs, Christina

2013-01-01

Durch thermische Entwässerung der Seltenerdmetall(SE)-Nitrat-Hydrate und der SE-Acetat-Hydrate im Argon-Strom/Vakuum konnten wasserfreie SE-Nitrate und SE-Nitrat-Monohydrate bzw. wasserfreie SE-Acetate erhalten werden. Es gelang zudem, SE-Oxyacetate durch thermische Zersetzung der SE-Acetate darzustellen. Des Weiteren wurde beim Erhitzen von Praseodym-Carbonat-Hydrat ein Pr-Carbonat-Hydroxid erhalten. Die Verbindungen wurden mittels Röntgenpulverdiffraktometrie und an ausgewählten Beispielen ...

Isolation of ethyl acetic based AGF bio-nutrient and its application on the growth of Capsicum annum L. plants

Science.gov (United States)

Hendrawan, Sonjaya, Yaya; Khoerunnisa, Fitri; Musthapa, Iqbal; Nurmala, Astri Rizki

2015-12-01

The study aimed to obtain the bionutrient derived from extraction of AGF leafs in ethyl acetic solvents and to explore its application on the plant growth of capsicum annum L. (curly red chili). Particularly, the fraction of secondary metabolites groups composed bionutrient was intensively elucidated by liquid vacuum chromatography technique. The characterization of secondary metabolites groups was conducted through several methods, i.e. thin layer chromatography, phytochemical screening, and FTIR spectroscopy. The AGF extracts based bionutrient then was applied on capsicum annum L. plants with dosage of 2 and 10 mL/L. The ethyl acetic solvent and commercial nutrient of Phonska and pesticide of curacron (EC 500) were selected as a blank and a positive control to evaluate the growth pattern of capsicum annum L., respectively. The result showed that the CF 1 dan CF2 of AGF extract contained alkaloid and terpenoid of secondary metabolite group, the CF 3, and CF 4 of AGF extracts were dominated by alkaloid, flavonoid, and terpenoid, while the CF 5 of AGF extract contained alkaloid, tannin and terpenoid groups. The CF 2 of AGF extract has the highest growth rate constant of 0.1702 week-1 with the number and heaviest mass of the yield of 82 pieces and 186.60, respectively. It was also showed the significant bio-pesticide activity that should be useful to support plant growth, indicating that AGF extract can be applied as both bio-nutrient and bio-pesticide.

A study of 11C-acetate production using 11C-choline commercial module

International Nuclear Information System (INIS)

Zhang Jinming; Tian Jiahe; Yao Shulin; Chen Yan

2008-01-01

Objective: 11 C-acetate is a useful PET tracer in evaluating myocardial metabolism but more interest has been focused on its application in tumor detection in recent years, especially hepatocellular carcinoma (HCC). This study was designed to evaluate the laboratory, preparation of 11 C-acetate with a modified 11 C-choline commercial module and to investigate its biodistribution in tumor (lung adenocarcinoma)-bearing mice as well as its potential as a tumor imaging agent. Methods: 11 C-acetate was synthesized with a modified 11 C choline module: Methyl magnesium bromide Grignard (0.1 ml of 1.5 mol/L) was load- ed to a Teflon loop before 11 CO 2 was recovered from the target. Cartier acetate solution (2 ml of 1 mmol/L) was pushed through the loop, SPE cartridges (mixed AG50 and IC-Ag) and then the QMA. The loop and cartridges were then rinsed with water. The product 11 C-acetate was then washed out from QMA with 0.9% NaCl solution into a collection vial containing diluted HCl. 11 C-carbonate was removed by nitrogen bubbling for 2 min. After neutralization with trisodium citrate, the injectable 11 C-acetate solution was obtained. The tumor-bearing mice were sacrificed. The percentage activity of injected dose per gram of tissue (% ID/g) for tumor and other tissues were calculated. One patient with known diagnosis of moderately differentiated HCC was injected with 11 C-acetate and imaged by PET/CT, followed by 18 F-fluorodeoxyglucose (FDG). Results: The synthesis yield of 11 C-acetate was (60.5 ± 8.7)% (decay conected, n=10); the radio-chemistry purity was > 98% and the synthesis time was 10 min from 11 CO 2 to 11 C-acetate. The radioactivity ratio for tumor/muscle was 1.76 at 30 min. A patient with known HCC showed positive 11 C-acetate accumulation in the tumor but was negative in 18 F-FDG. Conclusion: The synthesis of 11 C-acetate by modification of an 11 C-choline commercial module was feasible and it could be achieved with high yield, high radiochemical purity

Supportive treatment with megestrol acetate during radio-(chemo-)therapy. A randomized trial

International Nuclear Information System (INIS)

Fietkau, R.; Sauer, R.

1996-01-01

Background: The value of megestrol acetate in treating tumor anorexia and cachexia of terminal patients is well known. However, the supportive effect of megestrol acetate during intensive radio-(chemo-)therapy was not investigated up to now. Therefore a randomized trial was performed including patients with advanced tumors in the head and neck region. Patients and Methods: From June 1991 to December 1993 a total of 64 patients were admitted to a randomized, double-blind placebo-controlled study. During and up to 6 weeks following radiotherapy patients received 160 mg/d megestrol acetate or placebo. The nutritional status (anthropometric and laboratory parameters) and the quality-of-life index according to Padilla et al. were determined prior to therapy, 1, 4, 6 weeks later during radiotherapy and 12, 18 weeks after completion. Results: Sixty-one out of 64 patients were evaluable (control group: n=30; megestrol acetate patients: n=31). One patients refused further participation after randomization. One patient in each arm was excluded due to side effects (impotence, diarrhoea). Further side effects were not observed. In the control group the nutrititional parameters (body weight, triceps skinfold) and the subjective feeling of the patients deteriorated during radiotherapy and did not restore following radiotherapy. By contrast, the patients of the megestrol acetate group were able to stabilize these parameters. This difference was most prominent in the orally nourished patients (weight loss during therapy: Control group: -4.1 kg; megestrol acetate group: -0.8 kg; p=0.004); but not in the patients fed by percutaneous endoscopically guided gastrostomy (weight loss control group: -2.4 kg; megestrol acetate group: -0.8 kg; p=0.14). Conclusion: In patients on radiochemotherapy megestrol acetate prevents patients from further deterioration of the nutritional status and quality of life. (orig.) [de

Densified ultra-light cement-based materials

DEFF Research Database (Denmark)

Esteves, Luis Pedro

2015-01-01

be used as a “clean technology” in the production of cement-based materials for structural applications with a low carbon footprint. This paper describes the principles of this concept coupled with experimental results on the basic properties of this enhanced type of cement-based materials with combined...

Materials data base as an interface between fusion reactor designs and materials development

International Nuclear Information System (INIS)

Ishino, S.; Iwata, S.

1983-01-01

The materials data base is an integrated information system of experimental and/or calculated data of materials being compiled to meet the broad needs for materials data by taking advantage of the data base management systems. In this paper the objective of such computerized data base is described from the viewpoint of materials engineers and fusion system designers. Materials data spread themselves widely from the field that relates fundamental understanding of the behaviors of electrons, atoms, vacancies, dislocations and so on to the performance of components, devices, machines and systems. In our approach this information is described as ''relations'' by a set of tables which comprise related variables, for example, a set of values about essential properties for materials selection. This approach based on the relational model enables relational operations, i.e. SELECTION, PROJECTION, JOIN and so on, to select suitable materials, to set trade-off parameters for system designers and to establish design criteria. Stored data comprise (i) fundamental properties for all elements and potential structural materials, (ii) low cycle fatigue, irradiation creep and swelling data for type 316 stainless steels. These data have been selected and evaluated from critical reviews of existing data base of about 2 mega bytes data, some examples of materials selections and extraction of trade-off parameters are shown as a subject of critical issue concerning how to bridge the large gap between materials developments and system designs. (author)

Thermochemical properties of cellulose acetate blends with acetosolv and sawdust lignin: A comparative study.

Science.gov (United States)

Peredo, Karol; Escobar, Danilo; Vega-Lara, Johana; Berg, Alex; Pereira, Miguel

2016-02-01

Sawdust (SD) and cotton-lignin blends (CLB) were acetylated and the effect of lignin type and content on thermoplastic properties of the acetate produced was studied. The lignin in samples did not significantly affect the degree of acetylation. An increase in acetyl groups of 1-3% was observed in acetylated SD (ASD) unlike acetylated CLB (ACLB). Thermogravimetric analysis showed two thermal degradation zones; one at 190-200°C and the other at 330-370°C. The early degradation in ASD corresponds to galactoglucomannans while that in ACLB corresponds to the low-molecular-weight lignin. The second degradation is due to decomposition of cellulose acetate and high-molecular-weight lignin. DSC analysis showed homogeneous behaviour in ASD with only one glass transition temperature (Tg) at 170-180°C, unlike ACLB that showed two Tgs at 170-180°C. Sawdust acetylation, taking advantage of its residual lignin, showed higher reactivity and miscibility as compared to the same material produced by adding previously extracted lignin on cotton. Copyright © 2015 Elsevier B.V. All rights reserved.

Cellulose Acetate/N-TiO2 Biocomposite Flexible Films with Enhanced Solar Photochromic Properties

Science.gov (United States)

Radhika, T.; Anju, K. R.; Silpa, M. S.; Ramalingam, R. Jothi; Al-Lohedan, Hamad A.

2017-07-01

Flexible cellulose acetate/N-TiO2 nanocomposite films containing various concentrations of nanosized N-TiO2 and an intelligent methylene blue ink have been prepared by solution casting. The hydrothermally prepared nitrogen-doped titania (N-TiO2) and the films were characterized in detail. The photochromic properties of the prepared films were investigated under ultraviolet (UV), visible light, and simulated solar irradiation by UV-Vis spectrophotometry. Upon irradiation, the films exhibited rapid photochromic response that was reversible at room temperature. Films with higher content of nano N-TiO2 showed enhanced decoloration/recoloration under all irradiation conditions, with fast decoloration/recoloration under simulated solar irradiation. These results suggest that the amount of nano N-TiO2 in the composite, the concentration of methylene blue, and the solvent greatly influence the photochromic properties of the films. Such flexible and transparent cellulose acetate/N-TiO2 films with enhanced decoloration/recoloration properties under solar irradiation are promising smart materials for use in photoreversible printed electronics applications.

Copper-based nanoparticles prepared from copper (II acetate bipyridine complex

Directory of Open Access Journals (Sweden)

Lastovina Tatiana A.

2016-01-01

Full Text Available We report the synthesis of CuO, Cu/Cu2O and Cu2O/CuO nanoparticles (NPs from the single copper (II acetate bipyridine complex by three different methods:microwave-assisted, solvothermal and borohydride. Presence of bipyridine ligand in the copper complex would impose no need in additional stabilization during synthesis. The phases of formed NPs were identified by X-ray diffraction. CuO NPs of ~11 nm were obtained via solvothermal synthesis from alkaline solution at 160°C. The Cu/Cu2O NPs of ~80 nm were produced via microwave-assisted polyol procedure at 185-200°C, where ethylene glycol can play a triple role as a solvent, a reducing agent and a surfactant. The Cu2O/CuO NPs of ~16 nm were synthesized by a borohydride method at room temperature. Interplanar spacing calculated from the selected-area electron diffraction data confirmed the formation of Cu, CuO and Cu2O phases in respective samples. All NPs are stable and can be used for various applications including biomedicine.

Acetate:succinate CoA-transferase in the hydrogenosomes of Trichomonas vaginalis: Identification and characterization

NARCIS (Netherlands)

K.W.A. Grinsven; S. Rosnowsky (Silke); S.W.H. van Weelden (Susanne); S. Pütz (Simone); M. van der Giezen (Mark); W. Martin (William); J.J. van Hellemond (Jaap); A.G.M. Tielens (Aloysius); K. Henze (Katrin)

2008-01-01

textabstractAcetate:succinate CoA-transferases (ASCT) are acetate-producing enzymes in hydrogenosomes, anaerobically functioning mitochondria and in the aerobically functioning mitochondria of trypanosomatids. Although acetate is produced in the hydrogenosomes of a number of anaerobic microbial

Carbon isotope fractionation by sulfate-reducing bacteria using different pathways for the oxidation of acetate.

Science.gov (United States)

Goevert, Dennis; Conrad, Ralf

2008-11-01

Acetate is a key intermediate in the anaerobic degradation of organic matter. In anoxic environments, available acetate is a competitive substrate for sulfate-reducing bacteria (SRB) and methane-producing archaea. Little is known about the fractionation of carbon isotopes by sulfate reducers. Therefore, we determined carbon isotope compositions in cultures of three acetate-utilizing SRB, Desulfobacter postgatei, Desulfobacter hydrogenophilus, and Desulfobacca acetoxidans. We found that these species showed strong differences in their isotope enrichment factors (epsilon) of acetate. During the consumption of acetate and sulfate, acetate was enriched in 13C by 19.3% per hundred in Desulfobacca acetoxidans. By contrast, both D. postgatei and D. hydrogenophilus showed a slight depletion of 13C resulting in epsilon(ac)-values of 1.8 and 1.5% per hundred, respectively. We suggest that the different isotope fractionation is due to the different metabolic pathways for acetate oxidation. The strongly fractionating Desulfobacca acetoxidans uses the acetyl-CoA/carbon monoxide dehydrogenase pathway, which is also used by acetoclastic methanogens that show a similar fractionation of acetate (epsilon(ac) = -21 to -27% per hundred). In contrast, Desulfobacter spp. oxidize acetate to CO2 via the tricarboxylic acid (TCA) cycle and apparently did not discriminate against 13C. Our results suggestthat carbon isotope fractionation in environments with sulfate reduction will strongly depend on the composition of the sulfate-reducing bacterial community oxidizing acetate.

Dependence of Acetate-Based Antisolvents for High Humidity Fabrication of CH3NH3PbI3 Perovskite Devices in Ambient Atmosphere.

Science.gov (United States)

Yang, Fu; Kapil, Gaurav; Zhang, Putao; Hu, Zhaosheng; Kamarudin, Muhammad Akmal; Ma, Tingli; Hayase, Shuzi

2018-05-16

High-efficiency perovskite solar cells (PSCs) need to be fabricated in the nitrogen-filled glovebox by the atmosphere-controlled crystallization process. However, the use of the glovebox process is of great concern for mass level production of PSCs. In this work, notable efficient CH 3 NH 3 PbI 3 solar cells can be obtained in high humidity ambient atmosphere (60-70% relative humidity) by using acetate as the antisolvent, in which dependence of methyl, ethyl, propyl, and butyl acetate on the crystal growth mechanism is discussed. It is explored that acetate screens the sensitive perovskite intermediate phases from water molecules during perovskite film formation and annealing. It is revealed that relatively high vapor pressure and high water solubility of methyl acetate (MA) leads to the formation of highly dense and pinhole free perovskite films guiding to the best power conversion efficiency (PCE) of 16.3% with a reduced hysteresis. The devices prepared using MA showed remarkable shelf life stability of more than 80% for 360 h in ambient air condition, when compared to the devices fabricated using other antisolvents with low vapor pressure and low water solubility. Moreover, the PCE was still kept at 15.6% even though 2 vol % deionized water was added in the MA for preparing the perovskite layer.

A data base for aging of structural materials

International Nuclear Information System (INIS)

Oland, C.B.; Naus, D.J.; Jerath, S.

1993-01-01

USNRC initiated a Structural Aging (SAG) Program ORNL. The objective of the program is to provide assistance in identifying potential structural safety issues and to establish acceptance criteria for use in nuclear power plant evaluations for continued service. One main part focuses on the development of a Structural Materials Information Center where long-term and environment-dependent material properties are being collected and assembled into a data base. This data base is presented in two complementary formats. The Structural Materials Handbook is an expandable, hard-copy reference document that contains the complete data base for each material. The Structural Materials Electronic Data Base is accessible using an IBM-compatible personal computer. This paper presents an overview of the Structural Materials Information Center and briefly describes the features of the handbook and the electronic data base. In addition, a proposed method for using the data base to establish current property values for materials in existing concrete structures and to estimate the future performance of these materials is also presented

Ultrasound-assisted dyeing of cellulose acetate.

Science.gov (United States)

Udrescu, C; Ferrero, F; Periolatto, M

2014-07-01

The possibility of reducing the use of auxiliaries in conventional cellulose acetate dyeing with Disperse Red 50 using ultrasound technique was studied as an alternative to the standard procedure. Dyeing of cellulose acetate yarn was carried out by using either mechanical agitation alone, with and without auxiliaries, or coupling mechanical and ultrasound agitation in the bath where the temperature range was maintained between 60 and 80 °C. The best results of dyeing kinetics were obtained with ultrasound coupled with mechanical agitation without auxiliaries (90% of bath exhaustion value at 80 °C). Hence the corresponding half dyeing times, absorption rate constants according to Cegarra-Puente modified equation and ultrasound efficiency were calculated confirming the synergic effect of sonication on the dyeing kinetics. Moreover the apparent activation energies were also evaluated and the positive effect of ultrasound added to mechanical agitation was evidenced by the lower value (48 kJ/mol) in comparison with 112 and 169 kJ/mol for mechanical stirring alone with auxiliaries and without, respectively. Finally, the fastness tests gave good values for samples dyed with ultrasound technique even without auxiliaries. Moreover color measurements on dyed yarns showed that the color yield obtained by ultrasound-assisted dyeing at 80 °C of cellulose acetate without using additional chemicals into the dye bath reached the same value yielded by mechanical agitation, but with remarkably shorter time. Copyright © 2014 Elsevier B.V. All rights reserved.

Self-supported poly(methyl methacrylate-acrylonitrile-vinyl acetate)-based gel electrolyte for lithium ion battery

Energy Technology Data Exchange (ETDEWEB)

Liao, Y.H.; Zhou, D.Y.; Rao, M.M.; Cai, Z.P.; Liang, Y. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Li, W.S.; Tan, C.L. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Key Lab of Electrochemical Technology on Energy Storage and Power Generation in Guangdong Universities, Guangzhou 510006 (China)

2009-04-01

Self-supported gel polymer electrolyte (GPE) was prepared based on copolymer, poly(methyl methacrylate-acrylonitrile-vinyl acetate) (P(MMA-AN-VAc)). The copolymer P(MMA-AN-VAc) was synthesized by emulsion polymerization and the copolymer membrane was prepared through phase inversion. The structure and the performance of the copolymer, the membrane and the GPE were characterized by FTIR, NMR, SEM, XRD, DSC/TG, LSV, CA, and EIS. It is found that the copolymer was formed through the breaking of double bond C=C in each monomer. The membrane has low crystallinity and has low glass transition temperature, 39.1 C, its thermal stability is as high as 310 C, and its mechanical strength is improved compared with P(MMA-AN). The GPE is electrochemically stable up to 5.6 V (vs. Li/Li{sup +}) and its conductivity is 3.48 x 10{sup -3} S cm{sup -1} at ambient temperature. The lithium ion transference number in the GPE is 0.51 and the conductivity model of the GPE is found to obey the Vogel-Tamman-Fulcher (VTF) equation. (author)

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

International Nuclear Information System (INIS)

Kim, Young Chan; Oh, Ju Hyung; Yoon, Yup; Ko, Young Tae; Choi, Woo Suk; Kim, Eui Jong; Lim, Joo Won

1997-01-01

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

Isolation and characterization of acetate-utilizing anaerobes from a freshwater sediment

NARCIS (Netherlands)

Scholten, J.C.M.; Stams, A.J.M.

2000-01-01

Acetate-degrading anaerobic microorganisms in freshwater sediment were quantified by the most probable number technique. From the highest dilutions a methanogenic, a sulfate-reducing, and a nitrate-reducing microorganism were isolated with acetate as substrate. The methanogen (culture AMPB-Zg) was

The acetate switch of an intestinal pathogen disrupts host insulin signaling and lipid metabolism.

Science.gov (United States)

Hang, Saiyu; Purdy, Alexandra E; Robins, William P; Wang, Zhipeng; Mandal, Manabendra; Chang, Sarah; Mekalanos, John J; Watnick, Paula I

2014-11-12

Vibrio cholerae is lethal to the model host Drosophila melanogaster through mechanisms not solely attributable to cholera toxin. To examine additional virulence determinants, we performed a genetic screen in V. cholerae-infected Drosophila and identified the two-component system CrbRS. CrbRS controls transcriptional activation of acetyl-CoA synthase-1 (ACS-1) and thus regulates the acetate switch, in which bacteria transition from excretion to assimilation of environmental acetate. The resultant loss of intestinal acetate leads to deactivation of host insulin signaling and lipid accumulation in enterocytes, resulting in host lethality. These metabolic effects are not observed upon infection with ΔcrbS or Δacs1 V. cholerae mutants. Additionally, uninfected flies lacking intestinal commensals, which supply short chain fatty acids (SCFAs) such as acetate, also exhibit altered insulin signaling and intestinal steatosis, which is reversed upon acetate supplementation. Thus, acetate consumption by V. cholerae alters host metabolism, and dietary acetate supplementation may ameliorate some sequelae of cholera. Copyright © 2014 Elsevier Inc. All rights reserved.

Transports of acetate and haloacetate in Burkholderia species MBA4 are operated by distinct systems

Directory of Open Access Journals (Sweden)

Su Xianbin

2012-11-01

Full Text Available Abstract Background Acetate is a commonly used substrate for biosynthesis while monochloroacetate is a structurally similar compound but toxic and inhibits cell metabolism by blocking the citric acid cycle. In Burkholderia species MBA4 haloacetate was utilized as a carbon and energy source for growth. The degradation of haloacid was mediated by the production of an inducible dehalogenase. Recent studies have identified the presence of a concomitantly induced haloacetate-uptake activity in MBA4. This uptake activity has also been found to transport acetate. Since acetate transporters are commonly found in bacteria it is likely that haloacetate was transported by such a system in MBA4. Results The haloacetate-uptake activity of MBA4 was found to be induced by monochloroacetate (MCA and monobromoacetate (MBA. While the acetate-uptake activity was also induced by MCA and MBA, other alkanoates: acetate, propionate and 2-monochloropropionate (2MCPA were also inducers. Competing solute analysis showed that acetate and propionate interrupted the acetate- and MCA- induced acetate-uptake activities. While MCA, MBA, 2MCPA, and butyrate have no effect on acetate uptake they could significantly quenched the MCA-induced MCA-uptake activity. Transmembrane electrochemical potential was shown to be a driving force for both acetate- and MCA- transport systems. Conclusions Here we showed that acetate- and MCA- uptake in Burkholderia species MBA4 are two transport systems that have different induction patterns and substrate specificities. It is envisaged that the shapes and the three dimensional structures of the solutes determine their recognition or exclusion by the two transport systems.

Oxidation of sodium (2-14C) acetate with alkaline permanganate

International Nuclear Information System (INIS)

Zielinski, M.

1983-01-01

The mechanism and kinetics of the oxidation of sodium acetate with permanganate in alkile and neutral media have been investigated using (2- 14 C) acetate. The reaction is first order with respect to both permanganate and acetate ions. The initial second order rate constants depend linearly on the square of the hydroxide ion concentration. Arrhenius activation energy of the oxidation reaction carried out in 12M NaOH is 24.0 kcal/mole in the temperature interval of 50-100 deg C. The mechanism of the principal path leading to the oxalate formation and the mechanism of the side reaction resulting in the carbon dioxide production have been proposed and discussed. (author)

Learning material recommendation based on case-based reasoning similarity scores

Science.gov (United States)

Masood, Mona; Mokmin, Nur Azlina Mohamed

2017-10-01

A personalized learning material recommendation is important in any Intelligent Tutoring System (ITS). Case-based Reasoning (CBR) is an Artificial Intelligent Algorithm that has been widely used in the development of ITS applications. This study has developed an ITS application that applied the CBR algorithm in the development process. The application has the ability to recommend the most suitable learning material to the specific student based on information in the student profile. In order to test the ability of the application in recommending learning material, two versions of the application were created. The first version displayed the most suitable learning material and the second version displayed the least preferable learning material. The results show the application has successfully assigned the students to the most suitable learning material.

Ru decorated carbon nanotubes - a promising catalyst for reforming bio-based acetic acid in the aqueous phase

NARCIS (Netherlands)

de Vlieger, Dennis; Lefferts, Leonardus; Seshan, Kulathuiyer

2014-01-01

Catalytic reforming of biomass derived waste streams in the aqueous phase is a promising process for the production of sustainable hydrogen. Acetic acid will be a major component (up to 20 wt%) in many anticipated gasification feed streams (e.g. the aqueous fraction of pyrolysis oil). Conventional

Endogenous lycopene improves ethanol production under acetic acid stress in Saccharomyces cerevisiae.

Science.gov (United States)

Pan, Shuo; Jia, Bin; Liu, Hong; Wang, Zhen; Chai, Meng-Zhe; Ding, Ming-Zhu; Zhou, Xiao; Li, Xia; Li, Chun; Li, Bing-Zhi; Yuan, Ying-Jin

2018-01-01

Acetic acid, generated from the pretreatment of lignocellulosic biomass, is a significant obstacle for lignocellulosic ethanol production. Reactive oxidative species (ROS)-mediated cell damage is one of important issues caused by acetic acid. It has been reported that decreasing ROS level can improve the acetic acid tolerance of Saccharomyces cerevisiae . Lycopene is known as an antioxidant. In the study, we investigated effects of endogenous lycopene on cell growth and ethanol production of S. cerevisiae in acetic acid media. By accumulating endogenous lycopene during the aerobic fermentation of the seed stage, the intracellular ROS level of strain decreased to 1.4% of that of the control strain during ethanol fermentation. In the ethanol fermentation system containing 100 g/L glucose and 5.5 g/L acetic acid, the lag phase of strain was 24 h shorter than that of control strain. Glucose consumption rate and ethanol titer of yPS002 got to 2.08 g/L/h and 44.25 g/L, respectively, which were 2.6- and 1.3-fold of the control strain. Transcriptional changes of INO1 gene and CTT1 gene confirmed that endogenous lycopene can decrease oxidative stress and improve intracellular environment. Biosynthesis of endogenous lycopene is first associated with enhancing tolerance to acetic acid in S. cerevisiae . We demonstrate that endogenous lycopene can decrease intracellular ROS level caused by acetic acid, thus increasing cell growth and ethanol production. This work innovatively   puts forward a new strategy for second generation bioethanol production during lignocellulosic fermentation.

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria

International Nuclear Information System (INIS)

Aydin, Y. Andelib; Aksoy, Nuran Deveci

2010-01-01

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

The photochemistry of ring-substituted cinnamyl acetates

International Nuclear Information System (INIS)

Fleming, S.A.; Renault, L.; Grundy, E.C.; Pincock, J.A.

2006-01-01

The photochemistry of the (E)-cinnamyl acetates ((E)-1-aryl-3-propenyl acetates, 8a-8e) with substituents H, 4-CH 3 O, 3-CH 3 O, 4-CF 3 , and 3-CF 3 , respectively, was examined in both cyclohexane and methanol solvents. Alkene isomerization (E to Z) occurred more efficiently than other reactions and evidence is presented that this process occurs from the excited triplet state. In a slower process, 1,3-migration of the acetoxy group led to the rearranged 3-aryl-3-propenyl acetate isomers (9a-9e) as the major pathway, particularly in cylohexane. In methanol, the isomeric ethers 3-aryl-3-methoxypropene (14) and 1-aryl-3-methoxypropene (15) were formed by reaction of methanol with the photochemically generated cation. The combined yield of 14 and 15 (95% and 5%, respectively) was quantitative for the 4-methoxyphenyl compound (8b). Independent irradiations of the isomers 9a-9c demonstrated that the ethers 14 and 15 were primary photoproducts from 8 and not secondary photoproducts from 9. Fluorescence quantum yields and excited singlet state lifetimes indicated that the reactions, other than the E to Z isomerization, are from the excited singlet state. (author)

Chemical radiolabeling of carboxyatractyloside by [14C]acetic anhydride

International Nuclear Information System (INIS)

Block, M.R.; Pougeois, R.; Vignais, P.V.

1980-01-01

The authors report the synthesis and biological properties of a radiolabeled derivative of CAT obtained with acetylation of the primary alcohol of CAT with radiolabeled acetic anhydride. They also investigate the question of mutual exclusion of CAT and BA for binding to the mitochondrial ADP/ATP carrier in double labeling experiments based on the use of [ 3 H]BA and [ 14 C]Ac-CAT. The results are consistent with the view that the ADP/ATP carrier possesses two separate interacting binding sites for AT (or CAT) and for BA. (Auth.)

Acetic Acid Causes Endoplasmic Reticulum Stress and Induces the Unfolded Protein Response in Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Nozomi Kawazoe

2017-06-01

Full Text Available Since acetic acid inhibits the growth and fermentation ability of Saccharomyces cerevisiae, it is one of the practical hindrances to the efficient production of bioethanol from a lignocellulosic biomass. Although extensive information is available on yeast response to acetic acid stress, the involvement of endoplasmic reticulum (ER and unfolded protein response (UPR has not been addressed. We herein demonstrated that acetic acid causes ER stress and induces the UPR. The accumulation of misfolded proteins in the ER and activation of Ire1p and Hac1p, an ER-stress sensor and ER stress-responsive transcription factor, respectively, were induced by a treatment with acetic acid stress (>0.2% v/v. Other monocarboxylic acids such as propionic acid and sorbic acid, but not lactic acid, also induced the UPR. Additionally, ire1Δ and hac1Δ cells were more sensitive to acetic acid than wild-type cells, indicating that activation of the Ire1p-Hac1p pathway is required for maximum tolerance to acetic acid. Furthermore, the combination of mild acetic acid stress (0.1% acetic acid and mild ethanol stress (5% ethanol induced the UPR, whereas neither mild ethanol stress nor mild acetic acid stress individually activated Ire1p, suggesting that ER stress is easily induced in yeast cells during the fermentation process of lignocellulosic hydrolysates. It was possible to avoid the induction of ER stress caused by acetic acid and the combined stress by adjusting extracellular pH.

Biological caproate production by Clostridium kluyveri from ethanol and acetate as carbon sources

DEFF Research Database (Denmark)

Yin, Yanan; Zhang, Yifeng; Karakashev, Dimitar Borisov

2017-01-01

Caproate is a valuable industrial product and chemical precursor. In this study, batch tests were conducted to investigate the fermentative caproate production through chain elongation from acetate and ethanol. The effect of acetate/ethanol ratio and initial ethanol concentration on caproate...... production was examined. When substrate concentration was controlled at 100 mM total carbon, hydrogen was used as an additional electron donor. The highest caproate concentration of 3.11 g/L was obtained at an ethanol/acetate ratio of 7:3. No additional electron donor was needed upon an ethanol/acetate ratio...... ≥7:3. Caproate production increased with the increase of carbon source until ethanol concentration over 700 mM, which inhibited the fermentation process. The highest caproate concentration of 8.42 g/L was achieved from high ethanol strength wastewater with an ethanol/acetate ratio of 10:1 (550 m...

A data base for aging of structural materials

International Nuclear Information System (INIS)

Oland, C.B.; Naus, D.J.; Jerath, S.

1993-01-01

The U.S. Nuclear Regulatory Commission (USNRC) initiated a Structural Aging (SAG) Program at the Oak Ridge National Laboratory (ORNL). The objective of the program is to provide assistance in identifying potential structural safety issues and to establish acceptance criteria for use in nuclear power plant evaluations for continued service. One of the main parts of the program focuses on the development of a Structural Materials Information Center where long-term and environment-dependent material properties are being collected and assembled into a data base. This data base is presented in two complementary formats. The Structural Materials Handbook is an expandable, hard-copy reference document that contains the complete data base for each material. The Structural Materials Electronic Data Base is accessible using an IBM-compatible personal computer. This paper presents an overview of the Structural Materials Information Center and briefly describes the features of the handbook and the electronic data base. In addition, a proposed method for using the data base to establish current property values for materials in existing concrete structures and to estimate the future performance of these materials is also presented. (author)

Effect of ammonium and acetate on methanogenic pathway and methanogenic community composition

DEFF Research Database (Denmark)

Fotidis, Ioannis; Karakashev, Dimitar Borisov; Kotsopoulos, T. A.

2013-01-01

exposure to different ammonia concentrations. The methanogenic pathway was determined by following the production of (14) CH(4) and (14) CO(2) from acetate labeled in the methyl group (C-2). Microbial communities' composition was determined by fluorescence in situ hybridization. Upon acclimatization......Methanogenesis from acetate (aceticlastic methanogenesis or syntrophic acetate oxidation (SAO) coupled with hydrogenotrophic methanogenesis) is the most important step for the biogas process. The major environmental factors influencing methanogenesis are volatile fatty acids, ammonia, p...

Kinetics of butyrate, acetate, and hydrogen metabolism in a thermophilic, anaerobic, butyrate-degrading triculture.

Science.gov (United States)

Ahring, B K; Westermann, P

1987-02-01

Kinetics of butyrate, acetate, and hydrogen metabolism were determined with butyrate-limited, chemostat-grown tricultures of a thermophilic butyrate-utilizing bacterium together with Methanobacterium thermoautotrophicum and the TAM organism, a thermophilic acetate-utilizing methanogenic rod. Kinetic parameters were determined from progress curves fitted to the integrated form of the Michaelis-Menten equation. The apparent half-saturation constants, K(m), for butyrate, acetate, and dissolved hydrogen were 76 muM, 0.4 mM, and 8.5 muM, respectively. Butyrate and hydrogen were metabolized to a concentration of less than 1 muM, whereas acetate uptake usually ceased at a concentration of 25 to 75 muM, indicating a threshold level for acetate uptake. No significant differences in K(m) values for butyrate degradation were found between chemostat- and batch-grown tricultures, although the maximum growth rate was somewhat higher in the batch cultures in which the medium was supplemented with yeast extract. Acetate utilization was found to be the rate-limiting reaction for complete degradation of butyrate to methane and carbon dioxide in continuous culture. Increasing the dilution rate resulted in a gradual accumulation of acetate. The results explain the low concentrations of butyrate and hydrogen normally found during anaerobic digestion and the observation that acetate is the first volatile fatty acid to accumulate upon a decrease in retention time or increase in organic loading of a digestor.

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

DEFF Research Database (Denmark)

Xu, Jian; Hedegaard, Mette Christina; Thomsen, Anne Belinda

2009-01-01

Acetic acid-catalyzed hydrothermal pretreatment was done on corn stover under 195 °C, 15 min with the acetic acid ranging from 5 × 10−3 to 0.2 g g−1 corn stover. After pretreatment, the water-insoluble solids (WISs) and liquors were collected respectively. Arabinan recoveries from both WIS...... and liquors were investigated. The results indicate that there was no detectable arabinan left in the WIS when the acetic acid of 0.1 and 0.2 g g−1 corn stover were used in the pretreatment. The arabinan contents in the other WISs were not more than 10%. However, the arabinan found in the liquors...... was not covering the amount of arabinan released from the raw corn stover. For the arabinan recovery from liquor fractions, the highest of 43.57% was obtained by the pretreatment of acetic acid of 0.01 g g−1 of corn stover and the lowest was only 26.77% when the acetic acid of 0.2 g g−1 corn stover was used...

Hydrogenation of ethyl acetate on Re/γ-A12O3 catalyst

International Nuclear Information System (INIS)

Minachev, K.M.; Avaev, V.I.; Ryashentseva, M.A.

1986-01-01

This paper presents a study of the catalytic properties of 5% Re/gamma-A1 2 O 3 contact in the hydrogenation reaction of ethyl acetate (EA). To clarify the paths of formation of the by products, experiments were also carried out with ethanol under the conditions of hydrogenation of EA. It is shown that the main product of the hydrogenation of EA is ethanol. In addition, Et 2 O, water, and traces of acetaldehyde were found in the catalyzate. In the range of conditions studied, the maximal conversion of ethyl acetate into ethanol is 49%. Increase in the temperature and molar ratio, and also decrease in pressure leads to a decrease in the selectivity of hydrogenation of ethyl acetate into ethanol. Byproducts of the hydrogenation of ethyl acetate - diethyl ether and hydrocarbons - are formed not only as a result of dehydration of ethanol on gamma-A1 2 O 3 , but also directly from ethyl acetate (diethyl ether) and also by the hydrogenolysis of the C-O bond in ethanol on rhenium (hydrocarbons)

Formulation development and characterization of cellulose acetate nitrate based propellants for improved insensitive munitions properties

Directory of Open Access Journals (Sweden)

Thelma Manning

2014-06-01

Full Text Available Cellulose acetate nitrate (CAN was used as an insensitive energetic binder to improve the insensitive munitions (IM properties of gun propellants to replace the M1 propellant used in 105 mm artillery charges. CAN contains the energetic nitro groups found in nitrocellulose (NC, but also acetyl functionalities, which lowered the polymer's sensitivity to heat and shock, and therefore improved its IM properties relative to NC. The formulation, development and small-scale characterization testing of several CAN-based propellants were done. The formulations, using insensitive energetic solid fillers and high-nitrogen modifiers in place of nitramine were completed. The small scale characterization testing, such as closed bomb testing, small scale sensitivity, thermal stability, and chemical compatibility were done. The mechanical response of the propellants under high-rate uni-axial compression at, hot, cold, and ambient temperatures were also completed. Critical diameter testing, hot fragment conductive ignition (HFCI tests were done to evaluate the propellants' responses to thermal and shock stimuli. Utilizing the propellant chemical composition, theoretical predictions of erosivity were completed. All the small scale test results were utilized to down-select the promising CAN based formulations for large scale demonstration testing such as the ballistic performance and fragment impact testing in the 105 mm M67 artillery charge configurations. The test results completed in the small and large scale testing are discussed.

Sorption of water vapor in partially hydrolyzed poly(vinyl acetate)

International Nuclear Information System (INIS)

Spencer, H.G.; Honeycutt, S.C.

1973-01-01

The sorption kinetics of H 2 O and D 2 O in copolymers of partially hydrolyzed poly(vinyl acetate) were studied and compared with the sorption kinetics of vinyl acetate--vinyl alcohol copolymers, and poly(vinyl alcohol). The special measurement problems presented by transient-state sorption studies in water vapor--polymer systems and their effects on the results are discussed

Triarylborane-Based Materials for OLED Applications

Directory of Open Access Journals (Sweden)

Gulsen Turkoglu

2017-09-01

Full Text Available Multidisciplinary research on organic fluorescent molecules has been attracting great interest owing to their potential applications in biomedical and material sciences. In recent years, electron deficient systems have been increasingly incorporated into fluorescent materials. Triarylboranes with the empty p orbital of their boron centres are electron deficient and can be used as strong electron acceptors in conjugated organic fluorescent materials. Moreover, their applications in optoelectronic devices, energy harvesting materials and anion sensing, due to their natural Lewis acidity and remarkable solid-state fluorescence properties, have also been investigated. Furthermore, fluorescent triarylborane-based materials have been commonly utilized as emitters and electron transporters in organic light emitting diode (OLED applications. In this review, triarylborane-based small molecules and polymers will be surveyed, covering their structure-property relationships, intramolecular charge transfer properties and solid-state fluorescence quantum yields as functional emissive materials in OLEDs. Also, the importance of the boron atom in triarylborane compounds is emphasized to address the key issues of both fluorescent emitters and their host materials for the construction of high-performance OLEDs.

78 FR 66936 - Advisory Council for the Elimination of Tuberculosis (ACET)

Science.gov (United States)

2013-11-07

... Council for the Elimination of Tuberculosis (ACET) In accordance with section 10(a)(2) of the Federal... Health, and the Director, CDC, regarding the elimination of tuberculosis. Specifically, the Council makes... tuberculosis. Matters To Be Discussed: Agenda items include the following topics: (1) ACET Chair's report to...

Effect of sulfate and nitrate on acetate conversion by anaerobic microorganisms in a freshwater sediment.

Science.gov (United States)

Scholten, Johannes C M; Bodegom, Peter M; Vogelaar, Jaap; Ittersum, Alexander; Hordijk, Kees; Roelofsen, Wim; Stams, Alfons J M

2002-12-01

Acetate is quantitatively the most important substrate for methane production in a freshwater sediment in The Netherlands. In the presence of alternative electron acceptors the conversion of acetate by methanogens was strongly inhibited. By modelling the results, obtained in experiments with and without (13)C-labelled acetate, we could show that the competition for acetate between methanogens and sulfate reducers is the main cause of inhibition of methanogenesis in the sediment. Although nitrate led to a complete inhibition of methanogenesis, acetate-utilising nitrate-reducing bacteria hardly competed with methanogens for the available acetate in the presence of nitrate. Most-probable-number enumerations showed that methanogens (2x10(8) cells cm(-3) sediment) and sulfate reducers (2x10(8) cells cm(-3) sediment) were the dominant acetate-utilising organisms in the sediment, while numbers of acetate-utilising nitrate reducers were very low (5x10(5) cells cm(-3) sediment). However, high numbers of sulfide-oxidising nitrate reducers were detected. Denitrification might result in the formation of toxic products. We speculate that the accumulation of low concentrations of NO (<0.2 mM) may result in an inhibition of methanogenesis.

Interspecies acetate transfer influences the extent of anaerobic benzoate degradation by syntrophic consortia

Energy Technology Data Exchange (ETDEWEB)

Warikoo, V.; McInerney, M.J.; Suflita, J.M. [and others

1997-03-01

Benzoate degradation by an anaerobic, syntrophic bacterium, strain SB, in coculture with Desulfovibrio strain G-11 reached a threshold value which depended on the amount of acetate added, and ranged from about 2.5 to 29.9 {mu}M. Increasing acetate concentrations also uncompetitively inhibited benzoate degradation. The apparent V{sub max} and K{sub m} for benzoate degradation decreased with increasing acetate concentration, but the benzoate degradation capacity (V{sub max}/K{sub m}) of cell suspensions remained comparable. The addition of an acetate-using bacterium to cocultures after the threshold was reached resulted in the degradation of benzoate to below the detection limit. Mathematical simulations showed that the benzoate threshold was not predicted by the inhibitory effect of acetate on benzoate degradation kinetics. With nitrate instead of sulfate as the terminal electron acceptor, no benzoate threshold was observed in the presence of 20 mM acetate even though the degradation capacity was lower with nitrate than with sulfate. When strain SB was grown with a hydrogen-using partner that had a 5-fold lower hydrogen utilization capacity, a 5 to 9-fold lower the benzoate degradation capacity was observed compared to SB/G-11 cocultures. The Gibb`s free energy for benzoate degradation was less negative in cell suspensions with threshold compared to those without threshold. These studies showed that the threshold was not a function of the inhibition of benzoate degradation capacity by acetate, or the toxicity of the undissociated form of acetate. Rather a critical or minimal Gibb`s free energy may exist where thermodynamic constraints preclude further benzoate degradation.

Membrane-based biomolecular smart materials

International Nuclear Information System (INIS)

Sarles, Stephen A; Leo, Donald J

2011-01-01

Membrane-based biomolecular materials are a new class of smart material that feature networks of artificial lipid bilayers contained within durable synthetic substrates. Bilayers contained within this modular material platform provide an environment that can be tailored to host an enormous diversity of functional biomolecules, where the functionality of the global material system depends on the type(s) and organization(s) of the biomolecules that are chosen. In this paper, we review a series of biomolecular material platforms developed recently within the Leo Group at Virginia Tech and we discuss several novel coupling mechanisms provided by these hybrid material systems. The platforms developed demonstrate that the functions of biomolecules and the properties of synthetic materials can be combined to operate in concert, and the examples provided demonstrate how the formation and properties of a lipid bilayer can respond to a variety of stimuli including mechanical forces and electric fields

Ethanol and Acetate Acting as Carbon/Energy Sources Negatively Affect Yeast Chronological Aging

Directory of Open Access Journals (Sweden)

Ivan Orlandi

2013-01-01

Full Text Available In Saccharomyces cerevisiae, the chronological lifespan (CLS is defined as the length of time that a population of nondividing cells can survive in stationary phase. In this phase, cells remain metabolically active, albeit at reduced levels, and responsive to environmental signals, thus simulating the postmitotic quiescent state of mammalian cells. Many studies on the main nutrient signaling pathways have uncovered the strong influence of growth conditions, including the composition of culture media, on CLS. In this context, two byproducts of yeast glucose fermentation, ethanol and acetic acid, have been proposed as extrinsic proaging factors. Here, we report that ethanol and acetic acid, at physiological levels released in the exhausted medium, both contribute to chronological aging. Moreover, this combined proaging effect is not due to a toxic environment created by their presence but is mainly mediated by the metabolic pathways required for their utilization as carbon/energy sources. In addition, measurements of key enzymatic activities of the glyoxylate cycle and gluconeogenesis, together with respiration assays performed in extreme calorie restriction, point to a long-term quiescent program favoured by glyoxylate/gluconeogenesis flux contrary to a proaging one based on the oxidative metabolism of ethanol/acetate via TCA and mitochondrial respiration.

Morphologies of Sol–Gel Derived Thin Films of ZnO Using Different Precursor Materials and their Nanostructures

Directory of Open Access Journals (Sweden)

Chandra Sudhir

2007-01-01

Full Text Available AbstractWe have shown that the morphological features of the sol–gel derived thin films of ZnO depend strongly on the choice of the precursor materials. In particular, we have used zinc nitrate and zinc acetate as the precursor materials. While the films using zinc acetate showed a smoother topography, those prepared by using zinc nitrate exhibited dendritic character. Both types of films were found to be crystalline in nature. The crystallite dimensions were confined to the nanoscale. The crystallite size of the nanograins in the zinc nitrate derived films has been found to be smaller than the films grown by using zinc acetate as the precursor material. Selected area electron diffraction patterns in the case of both the precursor material has shown the presence of different rings corresponding to different planes of hexagonal ZnO crystal structure. The results have been discussed in terms of the fundamental considerations and basic chemistry governing the growth kinetics of these sol–gel derived ZnO films with both the precursor materials.

The study of 2-acetylaminotoluene ozonolysis in acetic ACID

OpenAIRE

Галстян, Андрій Генрійович

2014-01-01

The kinetics and mechanism of ozone reaction with 2-aminotoluene and its acylated derivative in acetic acid were studied in order to determine the possibility of obtaining 2-aminobenzoic acid.It is shown that the 2-aminotoluene ozonolysis reaction in acetic acid solution runs at high speed, and preferably on the free electron pair of the amino group to form mainly resinous compounds; oxidation products by the methyl group of the substrate are not formed under these conditions. The ozone attac...

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

International Nuclear Information System (INIS)

Salehi, E.; Naderi, Reza; Ramezanzadeh, B.

2017-01-01

Highlights: • An organic/inorganic hybrid green corrosion inhibitive pigment was synthesized and characterized. • Chemical structure and morphology of the hybrid complex were characterized. • Zinc acetate/Urtica Dioica showed effective inhibition action in saline solution on carbon steel. • The synergistic effect between Zn 2+ cations and inhibitive compounds existed in U.D resulted in protective film deposition on the steel surface. - Abstract: This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn 2+ and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

Energy Technology Data Exchange (ETDEWEB)

Salehi, E.; Naderi, Reza [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Ramezanzadeh, B., E-mail: ramezanzadeh@aut.ac.ir [Department of Surface Coatings and Corrosion, Institute for Color Science and Technology (ICST), PO 16765-654, Tehran (Iran, Islamic Republic of)

2017-02-28

Highlights: • An organic/inorganic hybrid green corrosion inhibitive pigment was synthesized and characterized. • Chemical structure and morphology of the hybrid complex were characterized. • Zinc acetate/Urtica Dioica showed effective inhibition action in saline solution on carbon steel. • The synergistic effect between Zn{sup 2+} cations and inhibitive compounds existed in U.D resulted in protective film deposition on the steel surface. - Abstract: This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn{sup 2+} and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

New insights into the mechanisms of acetic acid resistance in Acetobacter pasteurianus using iTRAQ-dependent quantitative proteomic analysis.

Science.gov (United States)

Xia, Kai; Zang, Ning; Zhang, Junmei; Zhang, Hong; Li, Yudong; Liu, Ye; Feng, Wei; Liang, Xinle

2016-12-05

Acetobacter pasteurianus is the main starter in rice vinegar manufacturing due to its remarkable abilities to resist and produce acetic acid. Although several mechanisms of acetic acid resistance have been proposed and only a few effector proteins have been identified, a comprehensive depiction of the biological processes involved in acetic acid resistance is needed. In this study, iTRAQ-based quantitative proteomic analysis was adopted to investigate the whole proteome of different acidic titers (3.6, 7.1 and 9.3%, w/v) of Acetobacter pasteurianus Ab3 during the vinegar fermentation process. Consequently, 1386 proteins, including 318 differentially expressed proteins (p150 proteins were differentially expressed. Specifically, proteins involved in amino acid metabolic processes and fatty acid biosynthesis were differentially expressed, which may contribute to the acetic acid resistance of Acetobacter. Transcription factors, two component systems and toxin-antitoxin systems were implicated in the modulatory network at multiple levels. In addition, the identification of proteins involved in redox homeostasis, protein metabolism, and the cell envelope suggested that the whole cellular system is mobilized in response to acid stress. These findings provide a differential proteomic profile of acetic acid resistance in Acetobacter pasteurianus and have potential application to highly acidic rice vinegar manufacturing. Copyright © 2016 Elsevier B.V. All rights reserved.

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

DEFF Research Database (Denmark)

Hanning, Christopher William

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......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...... 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...