Excess enthalpy,volume, and gibbs free energy; and viscosity of acetonitrile-methylcellosolve mixtures

Molar excess enthalpies of mixing at 48.2°C, and molar excess volumes at 40°C were measured for acetonitrile-methyl cellosolve system using an isothermal phase change calorimeter and a glass dilatometer respectively. Molar excess Gibbs free energies were calculated from the isothermal vapour-liquid equilibrium data obtained in a circulation still at 70, 60 and 48.2°C. Complete isobaric vapour-liquid equilibrium data at 1 atm pressure are also reported. The kinematic viscosity of binary mixtures were measured at 40°C with an Ostwald viscometer. The VLE data are corrected for vapour phase nonideality, tested for thermodynamic consistency and correlated by Wilson equation. The viscosity data were correlated by McAllister and excess function models.     

Trout‐Skin Gelatin‐Based Edible Films Containing Phenolic Antioxidants: Effect on Physical Properties and Oxidative Stability of Cod‐Liver Oil Model Food

Abstract: Trout‐skin (Oncorhynchus mykiss) gelatin‐based films containing antioxidants (epigallocatechin gallate (EGCG), 50 and 250 ppm w/w) and green tea powder (1% and 20% w/w of gelatin) were tested for tensile strength, elastic modulus, and elongation, and oxygen and water vapor transmission rates, in vitro antioxidant activity using the DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) assay and effect on stabilizing cod‐liver oil held under mild thermal abuse conditions. Cod‐liver oil overlaid with films was stored at 40 °C for 20 d and analyzed for peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Antioxidant activity was retained in films containing green tea powder, but was reduced (P < 0.05) in EGCG films (20 d, 23 °C). Water vapor transmission rate of the films incorporated with antioxidants did not change significantly (P > 0.05), but the oxygen transmission rate for films with 50 ppm EGCG and 20% green tea powder was significant (P < 0.05). Other physical properties varied with antioxidant incorporation. The TBARS and PV of control oil increased from 0.05 ± 0.01 to 4.71 ± 0.30 g MDA/kg oil and from 3.6 ± 0.2 to 178.3 ± 24.5 millieq peroxides/kg oil, respectively, after 20 d. For cod‐liver oil covered with control or antioxidant‐containing films, TBARS remained below 0.37 g MDA/kg oil and PV below 7 millieq peroxides/kg oil. Incorporation of antioxidants to the films did not reduce oil oxidation (P > 0.05) at the levels tested and this was confirmed by activation energy calculations. The rate of oil oxidation was more dependent upon the inherent oxygen barrier property of the films than the presence of antioxidants. Practical Application: This research has the potential to enhance the utilization of fish skins, a valuable food processing by‐product, as edible films with natural antioxidants to extend the shelf life of foods. The film physical properties and barrier to oxygen and water are investigated.     

Effect of optical turbulence in the dye medium on the bandwidth of a narrowband, high-repetition-rate dye laser

An analysis of turbulence in the dye medium of a high-repetition-rate narrowband dye laser is presented, and it is shown that the output bandwidth is proportional to the turbulence length scale, which depends on the Reynolds number. The length scale and the bandwidth both first decrease and then increase as the Reynolds number is increased from -200 to -20,000. The observed bandwidth, as we report and as in the published literature, confirms the validity of the analysis. A Rhodamine 6G grazing-incidence grating, stable dye laser transversely pumped by a copper-vapor laser was used in the experiments.     

Ternary vapour–liquid equilibrium data for the system: n-butanol–n-butyl acetate–1,2-propylene glycol

Vapour–liquid equilibrium data for the ternary system n-butanol–n-butyl acetate–1,2-propylene glycol are reported at pressures between 725 and 735 mm Hg. The activity coefficient data are satisfactorily correlated by Wohl's two-suffix van Laar equation. Thermodynamic consistency is checked by both the McDermott & Ellis point-to-point consistency test and by the Li & Lu closed-loop method.     

Vapour–liquid equilibrium data for n-butyl acetate–1,2-propylene glycol

Vapour–liquid equilibrium data for the binary system n-butyl acetate–1,2-propylene glycol have been obtained at pressures between 725 and 735 mm Hg. The activity coefficient data were correlated by Chao's modified Redlich Kister equation and van Laar's equation. The vapour composition was also correlated by the equations of Nagata and Hirata. Thermodynamic consistency was confirmed by Herington's area test.     

Pseudo diffusion of nonvolatile metals in electro graphite

The apparent diffusion coefficients for Ti, V, Cr, Nb, Mo and Hf as carbides and for elementary Fe, Ni and Cu in electro graphite have been determined by means of an electron-microprobe analyzer. These pseudo diffusion coefficients were found to vary with the heat treatment time. However, after one hour these remain constant and follow the Arrhenius type of relation D = D₀exp(?Q/RT). The activation energy Q was nearly constant for the metals investigated. An attempt was made to correlate the frequency factor D₀ with the heat of formation $\text{ΔH}{}_{\mathrm{?}}{}^{298}$ of the corresponding carbides. A plot of log D₀vsΔH_f yielded two straight lines, one for the negative $\text{ΔH}{}_{\mathrm{?}}$, the other for positive $\text{ΔH}{}_{\mathrm{?}}$. This method was satisfactorily applied to predict the diffusion coefficients of Zr, Sb and Bi.     

Cytocompatible chitosan-graft-mPEG-based 5-fluorouracil-loaded polymeric nanoparticles for tumor-targeted drug delivery

Biodegradable materials like chitosan (CH) and methoxy polyethylene glycol (mPEG) are widely being used as drug delivery carriers for various therapeutic applications. In this study, copolymer (CH-g-mPEG) of CH and carboxylic acid terminated mPEG was synthesized by carbodiimide-mediated acid amine reaction. The resultant hydrophilic copolymer was characterized by Fourier transform infrared spectroscopy and ¹H NMR studies, revealing its relevant functional bands and proton peaks, respectively. Blank polymeric nanoparticles (B-PNPs) and 5-fluorouracil loaded polymeric nanoparticles (5-FU-PNPs) were formulated by ionic gelation method. Furthermore, folic acid functionalized FA-PNPs and FA-5-FU-PNPs were prepared for folate receptor-targeted drug delivery. FA-5-FU-PNPs were characterized by particle size, zeta potential, and in vitro drug release studies, resulting in 197.7?nm,?+29.9?mv, and sustained drug release of 88% in 24?h, respectively. Cytotoxicity studies were performed for FA-PNPs and FA-5-FU-PNPs in MCF-7 cell line, which exhibited a cell viability of 80 and 41%, respectively. In vitro internalization studies were carried out for 5-FU-PNPs and FA-5-FU-PNPs which demonstrated increased cellular uptake of FA-5-FU-PNPs by receptor-mediated transport. Significant (p?相似文献