Propionic Acid Solutions Research Articles

Formation of cubic defined Sm-Sn pyrochlore structures: application to OCM

A series of Sm-Sn pyrochlores were synthesized from propionic acid solutions of Sm 2O 3, SnCl 2 and BaCO 3. The addition of increasing amounts of water during preparation is shown to influence the BaCl 2 precipitation and the nature of the Sm, Sn containing species remaining in the solution. The mastership on this parameter permits the synthesis of doped Sm-Sn pyrochlores with well-known contents of barium and chlorine. The changes in conversion and C 2 selectivity observed in the oxidative coupling reaction is interpreted in the light of a better knowledge of the preparation procedure ( species present on the surface and in the bulk).

ゾル・ゲル法によるＢｉ系銅酸化物超伝導膜の作製と評価 ＩＩ

Bi-Pb-Sr-Ca-Cu-O superconducting films were prepared on poly- or single crystal MgO substrate by sol-gel method. For the starting solution, we used acetates-solutes propionic(C2H5COOH) or butyric acid(C3H7COOH) with or without the addition of aqueous ammonia. The films were prepared by repeating the process of coating and decomposition(at 700°Cfor30 min) 3-10 times and by fin ally sintering at 855°C for 12h. The increase of CH2 number of solvent and the addition of NH3⋅H2O increase the values of pH and viscosity of the solution. These increases make a film twice thickerthan the film obtained from propionic acid solution. For the film sample prepared using butyric acid solution with 6 vol% of NH3⋅H2O, the percentage of high-Tc phase was determined by XRD(002) lines to be 40%, which was higher by 7% than that of the film prepared using propionic acid solution. The highest value of Tco(77K) was obtained for the film using butyric acid-NH3⋅20 system.

Is droplet evaporation crucial in the mechanism of electrospray mass spectrometry?

AbstractEvaporation of solvent from charged droplets was found not to be a prerequisite to ion desorption in electrospray mass spectrometry. Evidence of evaporation was absent in an examination of the electrospray mass spectral profiles of cytochrome c and myoglobin in 0.2% acetic and propionic acid solutions; the pHs of these two acid solutions are expected to change in opposite directions with evaporation. The results strongly suggest that ions, as observed in electrospray mass spectrometry, are desorbed from solutions that have undergone minimal evaporation, in other words, at the beginning rather than later parts of the electrospray process. It is speculated that ions are desorbed directly from the solution‐air interface at the needle tip.

Effects of different organic acids on the adhesion between polyethylene film and aluminium foil

The effect of organic acids on the adhesion between the polyethylene layer and the aluminium foil in laminated food packaging material was studied after test packaging. A 3% (wt/wt) solution of acetic acid and equivalent solutions of propionic acid, citric acid and lactic acid were packed in envelopes consisting of: LDPE/paper/LDPE/Al foil/LDPE and stored at room temperature for 4 weeks. As previously reported, acetic acid caused a total delamination within a few days followed by a recovery back to 50% of the initial value after 2 weeks. The material stored in propionic acid showed a total delamination of LDPE and aluminium after 8 days of storage and remained at this level during the rest of the observing period. FR-IR scans and ESCA analysis showed a formation of a salt for both acetic acid and propionic acid. The package material in contact with citric acid, lactic acid and water did not show any marked change in adhesion or salt layer formation during the storage time.

Ultrasonic absorption spectroscopy between 5 and 3100 MHz on some aqueous polyelectrolyte solutions

The ultrasonic absorption coefficient has been measured as a function of frequency between 5 MHz and 3.1 GHz for aqueous solutions of polyacrylic acid and of its sodium, potassium, and tetraethylammonium salts. Unlike an aqueous solution of propionic acid, all polymer solutions clearly exhibit excess absorption. Within the frequency range under consideration the excess absorption spectra can be analytically represented by two Debye-type relaxation terms. At 25°C the corresponding relaxation times adopt values between 3 and 12.4 ns, and between 0.12 and 0.22ns, respectively. The former process is discussed in accordance with previous models. The relaxation of the polyacrylic acid solutions is assumed to be related to the formation of hydrogen bonds of the polymeric molecules and that of the polyacrylate solutions may be due to interactions of counterions with chain segments. The latter process, the existence of which has been first proven in this study, is likely to reflect rotational motions of carboxyl groups.

Salting-Out and Salting-in Effects in the Reversed-Phase Thin-Layer Chromatography of Dansylated Amino Acids. Effect of Acids

Abstract The retention of 15 dansylated amino acid derivatives was determined in aqueous solutions of formic, acetic, propionic and perchloric acid in reversed-phase thin-layer chromatography. The acids increased the retention of each derivatives at the low concentration range. This effect has been tentatively explained by the suppression of dissociation of polar groups in the solute molecules resulting in increased apparent lipophilicity (salting-out phenomenon). The higher concentrations of acid solutions decreased the retention (salting-in effect), the undissociated acid molecules probably act as an organic mobile phase. Both salting-in and salting-out phenomena can be simultaneously described by bilinear function. The polarity parameters of the amino acids, their hydrophobicity and the strength of the acid in the eluent simultaneously influence the retention.

Optical resolution and absolute configuration of a nonsteroidal antiinflammatory drug, 2‐(10,11‐Dihydro‐10‐oxodibenzo‐[b,f]thiepin‐2‐yl)propionic acid

The title compound (+/-)-1 (CN-100) was efficiently resolved into a pair of enantiomers by fractional crystallization of the diastereomeric salts of (-)- and (+)-phenylethylamine. The purity of the enantiomers was determined using the chiral cellulose column (CHIRALCEL OJ) which was allowed direct separation of the enantiomers. A separation factor (alpha) of 1.73 was obtained. X-Ray crystallographic analysis of the (+)-isomer [salt of (-)-1-(4-bromophenyl)ethylamine] showed that this enantiomer has S-configuration. Biological studies have shown that only the (+)-isomer has antiinflammatory activity. Racemizaiton of (-)-isomer was carried out by heating its propionic acid solution in the presence of mineral acid, such as HBr.

Photochemical conversion of o‐phenylenediamine and o‐aminophenol into heterocyclics

Abstracto‐Phenylenediamine is photo‐oxidized to phenazine‐2,3‐diamine in ethanolic or aqueous hydrochloric acid solution. In acetic or propionic acid solutions it forms benzimidazole derivatives. o‐Aminophenol in ethanol is photo‐oxidized to 2‐amino‐3H‐phenoxazin‐3‐one and two tetracyclic solvent addition products.

Penetration of theophylline and adenosine into excised human skin from binary and ternary vehicles: effect of a nonionic surfactant.

A nonionic surfactant, diethyleneglycol lauryl ether (PEG-2-L), increases the flux of either theophylline or adenosine by a factor of 2.2-2.7, when these are delivered from propionic acid solutions into human skin samples, with respect to propionic acid alone. At the same time, the flux of propionic acid from the same vehicles is decreased. Significant expansion of the partial molal volumes vi of both purines occurs following incorporation of PEG-2-L into their propionic acid solution. Hence, the enhancing effect of this surfactant arises mainly from an increase in the excess free energy of these solutes in the donor phase ("push" effect). Paraffin oil increases the flux of either drug from propionic acid by an entirely different mechanism. It enhances the flux of propionic acid into the skin, thus promoting the partitioning of the purine solute in the modified skin barrier ("pull" effect). Indeed, the magnitude of vi of either purine in propionic acid:paraffin oil solution gives no indication of a significant interaction between paraffin oil and the purine solute. Finally, the penetration enhancing effects of PEG-2-L and paraffin oil combined together in the same propionic acid vehicle are additive, resulting in a flux which is approximately the sum total of fluxes obtained separately with PEG-2-L or paraffin oil.

Thin-layer chromatography can resolve phosphotyrosine, phosphoserine, and phosphothreonine in a protein hydrolyzate

A solution of propionic acid, 1 m ammonium hydroxide, and isopropyl alcohol (45/17.5/17.5, v v ) was the ascending solvent in the separation of phosphotyrosine, phosphothreonine, and phosphoserine by thin-layer chromatography. The immobile phase was cellulose. The relative migrations were 0.44, 0.38, and 0.26, respectively. A previously described thin-layer system consisting of isobutyric acid and 0.5 m ammonium hydroxide ( 50 30 , v v ) gave very similar relative migrations. To determine the usefulness of thin-layer chromatography in phosphoamino acid analysis, the propionic acid/ammonium hydroxide/isopropyl alcohol solution was used to characterize phosphorylated residues in a plasma membrane protein which is a substrate for the insulin receptor kinase, in insulin receptor phosphorylated histone H2B, and in an in vivo phosphorylated 90000-Da protein from IM9 cells. 32P-labeled proteins were separated by dodecyl sulfate-gel electrophoresis, digested with trypsin, and then hydrolyzed with 6 n HCl, 2h, 110°C. Following thin-layer chromatography of the hydrolyzates and autoradiography, phosphotyrosine was detected in insulin receptor substrates, and phosphoserine and phosphothreonine were found in the in vivo-phosphorylated protein. This study supports previous reports about the practicality of thin-layer chromatography in phosphoamino acid analysis and it demonstrates that a propionic acid, ammonium hydroxide, isopropyl alcohol solution may be a useful ascending solvent mixture for this purpose.

Study on the synergistic extraction of cobalt(II) with lower fatty acids in the presence of heterocyclic amines and some metal ion separations

The synergistic extraction of cobalt(II) with a chloroform solution of propionic, butyric or valeric acid in the presence of β-picoline, pyridine or quinoline has been investigated. The effect of different variables, such as pH of the aqueous phase, and concentration of metal ion, acid and amine, is reported. On the basis of slope analysis the species extracted were generally found to be CoA 2.2HA.2B where HA is the acid and B the base, but CoA 2.HA.2B.H 2O for the butyric acid—quinoline system. The extraction constants were used to assess the relative effectiveness of the amines as synergists. From the extraction data, methods for separation of Co(II) from Mn(II), Cr(III), Fe(III), Zn(II), Cd(II) and Hg(II), with fairly high separation factors, have been worked out.

プロピオン酸水溶液およびクエン酸水溶液の逆浸透濃縮

Reverse osmotic concentration of aqueous propionic acid and citric acid solutions were carried out using composite membrane PEC-1000 supplied from Toray Co. Ltd., Separation of propionic acid and citric acid, and flux through the membrane were measured under the following conditions : concentration of propionic acid, 2.28, 4.67, 9.25, 12.3wt%, concentration of citric acid, 2, 4.3, 9, 12.3wt%, operating pressure, 2.94, 3.92, 5.49, 6.86Mpa. The measured separations of propionic acid were always above 94% and those of citric acid above 99.95%.An analysis of data with Spiegler-Kedem's transport model shows that the value of reflection coefficient σ, soulute and hydraulic permeabilities ω and Lp for propionic acid were 0.988, 2×10-11, 8.15×10-8, (mol/m2 pa. s), respectively, and those for citric acid 1.0, . 033×10-11, 8.52×10-8 (mol/m2pa. s) respectively.Energy and membrane area required were calculated to concentrate dilute propionic acid and citric acid solutions by reverse osmosis. The energy per one kilogram of concentrated propionic acid is propotional to pressure difference and depends on the final concentration and concentration polarization, and found 0.3 and 0.7 kwh/kg-PAc at 5 and 10 MPa respectively to concentrate up to 14.7wt% from 0.5wt%. The energy of concentrated citric acid is proportional to pressure difference and independs on the concentration polarization. The area for two solutions are inversely propotional to operating pressure, and found to be 0.2-0.9m2/ (kgPAc/day), 0.06-0.2m2/ (kgCAc/day).

Aggregation of larvae of the house cricket,Acheta domesticus (L.), by propionic acid present in the excreta

Acetic, propionic, butyric, isobutyric, valeric, and isovaleric acids have been identified in extracts of the excreta of the house cricket,Acheta domesticus (L.), by gas-liquid chromatography. Solutions of propionic acid applied to filter paper aggregated 1- to 2-week-old larvae, while solutions of acetic, butyric, valeric, and isovaleric acids were without effect.

Evaluation of Covering, Dry Matter, and Preservative at Ensiling of Alfalfa in Bunker Silos

In 1978, alfalfa at 30 or 40% dry matter was ensiled in four bunker silos. Propionic acid (.02% wet basis) was applied to one bunker of each dry matter. Bunkers were covered with black plastic. Dry matter recovery, temperatures during storage, and weight gain of heifers fed these silages were similar between treatments. In 1979, alfalfa (44% dry matter) was ensiled in four bunker silos of which two were not covered. Two silos, one covered and one not, were treated with propionic acid (.02% wet basis). Average temperatures during storage (7 wk) 34.1, 36.4, 42.6, and 50.3°C and dry matter recovery 84.1, 96.2, 86.3, and 68.0% were recorded for treated-covered, covered, treated-uncovered, and uncovered silos. Heifers gained more when fed untreated and covered silages. In 1980, alfalfa (32% dry matter) was ensiled in two bunkers. One silo was covered and untreated (covered), and the other was treated topically (treated) with a 100% propionic acid solution. Average temperatures during storage (7 wk) were 33.7 and 43.0° C, dry matter recovery 86.2 and 77.6%, average daily gain .58 and .44kg/day, and dry matter consumption 7.3 and 5.8kg/dry matter per day for silages or heifers fed covered and treated silages. In general, covering with black plastic was as effective as or more effective than treatment with propionic acid for preserving alfalfa stored in bunker silos.

Mechanical properties of chitosan films: Effect of solvent acid

AbstractThe apparent Young's modulus shows a linear relationship with junction density of chitosan films. The linear relationship of apparent Young's modulus with chitosan concentration is also observed. The linear relationship depends of the acid used in the casting solution. Relaxation times were of the order of 104 seconds, indicating a slow physical process. Stress‐relaxation behavior of swollen chitosan films, prepared by solvent casting from dilute acetic or propionic acid solutions, can be represented by a one‐component Maxwell model.

Concentration dependence of surface diffusion coefficient of propionic acid in activated carbon particles

AbstractA Wicke Kallenbach type steady state diffusion experiment was performed for varying concentrations of propionic acid solution through activated carbon pellets. Since surface diffusion is a dominant mechanism, concentration dependence of the surface diffusion coefficient is precisely determined from the change of diffusion flux with concentration. Strong dependence of surface diffusion coefficient on amount adsorbed is partially interpreted in terms of the change of heat of adsorption with surface coverage as determined from separate equilibrium runs.

Beef production from additive-treated silages

SUMMARY1. Wilted (32% dry matter) Italian ryegrass was conserved: (A) untreated; (B) with 16·3 g/kg dry matter (4·6 1/t of fresh material) of an 85% w/w formic acid additive; (C) 12·1 g/kg dry matter (2·3 1/t fresh material) each of 85% formic acid additive and formalin (40% w/v formaldehyde); (D) 5·8 g/kg dry matter (1·3 1/t fresh material) each of 85% formic acid additive, formalin and a 96% w/v solution of propionic acid. The silages were individually fed ad libitum to 40 15-mo-old British Friesian steers of about 350 kg initial live weight.2. Treatment with additives inhibited fermentation, resulting in silages with higher levels of water soluble carbohydrates and lower levels of organic acids than untreated material. Lower levels of ammonia N and higher levels of true protein indicated that some protein protection resulted from the formaldehyde treatment.3. Formic acid alone (B) had little effect on digestibility but significantly (P<0·05) enhanced dry-matter intake, live-weight gain and nitrogen retention relative to the control (A)4. Whereas the application of formaldehyde (Treatments C and D reduced the digestability in vivo of nitrogen, significant increases in nitrogen retention were recorde relative to the control (A). Dry matter intake was not affected significantly by treatment with formaldehyde, but at the higher level of application (Treatment C) daily gain was significantly reduced compared with the control (A). These effects are discussed in relation to possible changes in VFA patterns within the rumen and to the levels of formaldehyde used.

Structure and Properties of Precipitates of Poly(γ-benzyl glutamate)

Precipitates of poly(γ-benzyl glutamate) (PBG) were prepared from dimethylformamide—propionic acid solutions under various conditions. Electron micrographic observations and X-ray diffraction analyses of the precipitates thus obtained were carried out. The electron micrographs of the precipitates exhibited patterns similar to those reported by Ishikawa and Kurita, and Tachibana and Kambara (super helices), though lamella-like patterns (platelets) were observed under certain conditions. The viscoelastic properties, thermal analyses, and specific volume vs. temperature curves of the precipitates were investigated. As for the viscoelastic properties, the precipitates showed peaks of tanδ at 50°C and 120°C (110 Hz). The moduli E′ decreased remarkably near 120°C. In the thermal analyses an endothermic peak appeared in the vicinity of 130°C and a transition appeared at 132°C in the specific volume vs. temperature curve. The phenomena observed in the vicinity of 130°C were considered to be related to a breakdown of stacks of the benzene rings of PBG in the precipitates, from comparison with the properties of cast films reported previously. The electron micrographs of the precipitates from various helicogenic solvent—precipitant mixtures were the same as those of the precipitates from dimethylformamide—propionic acid solution.

Oxidation of propionic acid solutions

AbstractWet air oxidation is a process in which organic materials in the aqueous phase are oxidized by air at temperatures between 300°F and 600°F and pressures of 1000‐1800 psia. To improve our understanding of the process, its kinetics were studied using a propionic acid solution to simplify both analysis and rate measurements. The aim of the research was to define the regime where the reaction rate is kinetically controlled, to develop a model for the reaction rate and to interpret the model in terms of mechanism. Oxidation appears to proceed homogeneously in the aqueous phase and is probably kinetically controlled between 450° and 550°F. The oxidation appears to take place via two principal routes. Approximately half the propionic acid is oxidized completely to carbon dioxide while the oxidation of the remainder apparently proceeds via acetaldehyde as an intermediate to acetic acid. Acetic acid oxidizes only at a very low rate. A power law rate expression was developed which adequately described the oxidation of propionic acid solutions.

Effect of Ultrasonic Wave on the Electric Conductivity of Electrolyte Solutions

The electric conductivity of aqueous solutions of formic acid, acetic acid, propionic acid, hydrochloric acid, sodium chloride, sodium formate, sodium acetate, and sodium propionate was measured under the irradiation of ultrasonic wave. The conductivity increased and reached a limiting value within ten minutes. This change was found to be reversible. It was confirmed that the increase of conductivity was larger than that due to the rise in temperature caused by ultrasonic irradiation. In the case of hydrochloric acid, a pronounced increase of conductivity was observed. It seems that the protonic transition is affected more effectively by ultrasonic wave than the Stokes type migration.