scholarly journals Chemisorption of acetic acid onSi(100)−2×1at room temperature

2008 ◽  
Vol 77 (11) ◽  
Author(s):  
Han-Koo Lee ◽  
Ki-jeong Kim ◽  
Jin-hee Han ◽  
Tai-Hee Kang ◽  
J. W. Chung ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Room Temperature

Color and Antioxidant Changes in Various Natural Rubber Processes

2015 ◽  
Vol 754-755 ◽  
pp. 230-234 ◽  
Author(s):  
Suwimon Siriwong ◽  
Adisai Rungvichaniwat ◽  
Pairote Klinpituksa ◽  
Khalid Hamid Musa ◽  
Aminah Abdullah
Keyword(s):  
Acetic Acid ◽  
Natural Rubber ◽  
Retention Index ◽  
Total Phenolic Content ◽  
Room Temperature ◽  
Phenolic Content ◽  
Total Phenolic ◽  
Lovibond Colorimeter

Fresh field natural rubber was coagulated by acetic acid, soaked in water at room temperature (WRT) or 70°C (W70) for 1 hr, and then dried in an oven at 40°C. Non-soaked natural rubber samples (NoW) served as a control. Two grades of natural rubber, namely air-dry sheet (ADS) and ribbed smoked sheet No.3 (RSS3) derived from the same latex, were also investigated. All dry rubber samples were characterized with Lovibond colorimeter according to ASTM D3157, as well as with a HunterLab spectrophotometer. Furthermore, all the dry rubber samples were dissolved in a chloroform:methanol mixture (4:1 v:v). The rubber was then precipitated out of the solution with methanol, and the remaining solution was quantitatively analyzed for total phenolic content (TPC). The plasticity retention index (PRI) was determined for all the dried rubber samples according to ASTM D3194. It was found that WRT, W70 and ADS were similar in lightness L*, while RSS3 had the lowest L*. W70 had the lowest redness a*, which increased in the order WRT, NoW, RSS3 and ADS. W70 also had the lowest yellowness b*, which increased in the order RSS3, NoW and WRT and ADS. Moreover, TPC was the lowest for the W70 sample, increasing in the order ADS, WRT, NoW and RSS3. The PRI was highest for W70, and decreased in the order WRT, RSS3, NoW and ADS. All of the PRI values observed were comparatively high relative to blocked standard Thai rubber 20 (STR20).

scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
The Other ◽  
Other Hand ◽  
Three Component Reaction ◽  
High Yields

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

Mitigating the Antimicrobial Activities of Selected Organic Acids and Commercial Sanitizers with Various Neutralizing Agents

2011 ◽  
Vol 74 (5) ◽  
pp. 820-825 ◽  
Author(s):  
YOEN JU PARK ◽  
JINRU CHEN
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Organic Acids ◽  
Shiga Toxin ◽  
Room Temperature ◽  
Sodium Thiosulfate ◽  
Antimicrobial Activities ◽  
Phosphate Buffered Saline ◽  
Lactic Acids

This study was conducted to evaluate the abilities of five neutralizing agents, Dey-Engley (DE) neutralizing broth (single or double strength), morpholinepropanesulfonic acid (MOPS) buffer, phosphate-buffered saline (PBS), and sodium thiosulfate buffer, in mitigating the activities of acetic or lactic acid (2%) and an alkaline or acidic sanitizer (a manufacturer-recommended concentration) againt the cells of Shiga toxin–producing Escherichia coli (STEC; n = 9). To evaluate the possible toxicity of the neutralizing agents to the STEC cells, each STEC strain was exposed to each of the neutralizing agents at room temperature for 10 min. Neutralizing efficacy was evaluated by placing each STEC strain in a mixture of sanitizer and neutralizer under the same conditions. The neutralizing agents had no detectable toxic effect on the STEC strains. PBS was least effective for neutralizing the activity of selected organic acids and sanitizers. Single-strength DE and sodium thiosulfate neutralized the activity of both acetic and lactic acids. MOPS buffer neutralized the activity of acetic acid and lactic acid against six and five STEC strains, respectively. All neutralizing agents, except double-strength DE broth, had a limited neutralizing effect on the activity of the commercial sanitizers used in the study. The double-strength DE broth effectively neutralized the activity of the two commercial sanitizers with no detectable toxic effects on STEC cells.

scholarly journals Synthesis of Some 2-Amino-5-substituted-1,3,4-oxadiazole Derivatives in the Acetic Acid

2011 ◽  
Vol 8 (s1) ◽  
pp. S448-S454 ◽  
Author(s):  
Sanjeev Kumar
Keyword(s):  
Acetic Acid ◽  
Room Temperature ◽  
Platinum Electrode ◽  
Supporting Electrolyte ◽  
Saturated Calomel Electrode ◽  
Reference Electrode ◽  
Lithium Perchlorate ◽  
Environmentally Benign ◽  
Controlled Potential ◽  
Oxadiazole Derivatives

An environmentally benign method for the preparation of 2-amino-5-substituted-1,3,4-oxadiazoles (1a-n) at platinum electrode through the electrooxidation of semicarbazone at room temperature is reported. The electrolysis were carried out at controlled potential in acetic acid solvent using lithium perchlorate as supporting electrolyte in an undivided cell assembly. Square shaped plates of platinum were used for working as well as counter electrode and a third electrode saturated calomel electrode was used as a reference electrode for the measurement of potential difference between two electrodes during the electrolysis.

scholarly journals Dinuclear thiazolylidene copper complex as highly active catalyst for azid–alkyne cycloadditions

2016 ◽  
Vol 12 ◽  
pp. 1566-1572 ◽  
Author(s):  
Anne L Schöffler ◽  
Ata Makarem ◽  
Frank Rominger ◽  
Bernd F Straub
Keyword(s):  
Acetic Acid ◽  
Organic Solvents ◽  
Copper Complex ◽  
Room Temperature ◽  
Active Catalyst ◽  
Catalyst Design ◽  
Ancillary Ligand ◽  
Click Reactions ◽  
Highly Active ◽  
Cost Efficient

A dinuclear N-heterocyclic carbene (NHC) copper complex efficiently catalyzes azide–alkyne cycloaddition (CuAAC) “click” reactions. The ancillary ligand comprises two 4,5-dimethyl-1,3-thiazol-2-ylidene units and an ethylene linker. The three-step preparation of the complex from commercially available starting compounds is more straightforward and cost-efficient than that of the previously described 1,2,4-triazol-5-ylidene derivatives. Kinetic experiments revealed its high catalytic CuAAC activity in organic solvents at room temperature. The activity increases upon addition of acetic acid, particularly for more acidic alkyne substrates. The modular catalyst design renders possible the exchange of N-heterocyclic carbene, linker, sacrificial ligand, and counter ion.

scholarly journals Syntheses, Structures, and Characteristics of Three Metal Complexes Constructed Using Hexacarboxylic Acid

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4431 ◽  
Author(s):  
Lingshu Meng ◽  
Lun Zhao ◽  
Guanlin Guo ◽  
Xin Liu ◽  
Zhijun Liang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Thermogravimetric Analysis ◽  
Coordination Polymers ◽  
Electrochemical Behavior ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Hexadentate Ligand ◽  
Xrd Techniques

In this study, three new 3D coordination polymers (CPs), {[Cd3(L)(H2O)6]·H2O}n (1), {[Cu1.5(L)0.5(bimb)1.5]·5H2O·DMF}n (2), and {[Mn1.5(H3L)(bibp)0.5(H2O)2]·3H2O}n (3) (bimb= 1,3-bis(imidazol-1-yl)benzene, bibp= 1,4-bis((4-imidazol-1-yl)benzyl)piperazine), were prepared under solvothermal or hydrothermal conditions based on a hexadentate ligand (1,3,5-triazine-2,4,6-triamine hexa-acetic acid (H6L)). Structural elucidations were carried out by IR spectra along with single-crystal X-ray diffraction analysis, while thermogravimetric analysis (TGA) (dynamic and isothermal) and XRD techniques were used for property evaluations of the polymers. Furthermore, the fluorescence properties and detection of the Fe3+ ions in 1 were tested at room temperature, and the electrochemical behavior of 2 is also stated in this article.

Cold smoking of Lebranche mullet (Mugil liza): Physicochemical, sensory, and microbiological evaluation

2020 ◽  
pp. 108201322095167
Author(s):  
Rolando Jimenez Lugo ◽  
Silvina Paola Agustinelli ◽  
María Isabel Yeannes ◽  
Marina Czerner
Keyword(s):  
Acetic Acid ◽  
Room Temperature ◽  
Microbial Growth ◽  
Stability Range ◽  
Overall Acceptability ◽  
Smoked Fish ◽  
Ph Values ◽  
Nacl Concentration ◽  
Salty Taste ◽  
Bacterial Groups

The suitability of Mugil liza for cold smoking was evaluated and the effect of four different salting treatments on physicochemical, microbiological, and sensory characteristics was assessed. The addition of sucrose (3%) and acetic acid (0.5%) to the brine lead to fillet dehydration with lower NaCl penetration, combined with higher reduction of pH. Brining at refrigerated temperature (5 ± 1 ℃) instead of room temperature (16 ± 2 ℃) was more effective in preventing microbial growth. Loads of bacterial groups assessed in all smoked samples were below 100 CFU/g and the aw, moisture, NaCl, and pH values achieved were within the typical stability range of smoked fish products. The obtained products were characterized by the smoked aroma and salty taste, differing in 7 of the 21 evaluated descriptors. The use of acetic acid in brine formulation showed an effect over color and texture descriptors. The affective test indicated the overall acceptability of products, being preferred the samples treated in the lowest NaCl concentration (5%).

A LABORATORY STUDY OF GLEYING

1965 ◽  
Vol 45 (2) ◽  
pp. 199-206 ◽  
Author(s):  
J. A. McKeague
Keyword(s):  
Organic Matter ◽  
Acetic Acid ◽  
Room Temperature ◽  
Rate Of Change ◽  
Redox Potentials ◽  
Soil Columns ◽  
Flooded Soils ◽  
Soil Material ◽  
Effects Of Temperature ◽  
Extractable Iron

Columns of different soil materials with ground leaves at the surface were maintained for 18 months with the water table continuously above the surface, or fluctuating between the surface and 15 cm. Redox potentials, colors, and extractable iron were determined. The effects of temperature and of organic matter on the rate of change of Eh were studied with flooded soils in test tubes.The rate and degree of development of dull colors and mottling in the soil columns was influenced greatly by the nature of the soil material. Reduction effected marked increases in acetic acid extractable iron from all of the soil materials. Low redox potentials developed rapidly at room temperature in flooded soils containing appreciable amounts of organic matter. Eh values below 0 mv developed slowly in soils at 1 °C and at room temperature in some soils that were almost devoid of organic matter. Release of Fe+2 from ferrous minerals was thought to account for these low Eh values.

Infrared Study of Acetic Acid Solutions in CCl4

1995 ◽  
Vol 60 (7) ◽  
pp. 1094-1100 ◽  
Author(s):  
Ivona Malijevská ◽  
Martin Polášek
Keyword(s):  
Acetic Acid ◽  
Regression Analysis ◽  
Carbon Tetrachloride ◽  
Room Temperature ◽  
Equilibrium Constants ◽  
Acid Solutions ◽  
Standard State ◽  
Infrared Study ◽  
Mean Values ◽  
Linear Dimer

Spectra of acetic acid solutions in carbon tetrachloride were taken at room temperature over the concentration range 0.025-0.00125 mol dm-3. Solutions of acetic acid were modelled as an ideal mixture of monomers, and cyclic and linear dimers. Regression analysis effected separation of the experimental envelope into its component bands. Band shapes were approximated by a Lorenzian function with the resolved band peak frequencies 1 712 cm-1 for the cyclic dimer, 1 724 cm-1 for the linear dimer and 1 765 cm-1 for the acetic acid monomer. Mean values of equilibrium constants for the standard state of unit concentration are 2 700 for the cyclic and 393 for the linear dimer, respectively.

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