Search results for " Acetate"
showing 10 items of 517 documents
Considering syntrophic acetate oxidation and ionic strength improves the performance of models for food waste anaerobic digestion.
2021
Current mechanistic anaerobic digestion (AD) models cannot accurately represent the underlying processes occurring during food waste (FW) AD. This work presents an update of the Anaerobic Digestion Model no. 1 (ADM1) to provide accurate estimations of free ammonia concentrations and related inhibition thresholds, and model syntrophic acetate oxidation as acetate-consuming pathway. A modified Davies equation predicted NH3 concentrations and pH more accurately, and better estimated associated inhibitory limits. Sensitivity analysis results showed the importance of accurate disintegration kinetics and volumetric mass transfer coefficients, as well as volatile fatty acids (VFAs) and hydrogen up…
In Vitro Evaluation of Enteric-Coated HPMC Capsules—Effect of Formulation Factors on Product Performance
2020
A comparative study on different enteric-coated hard capsules was performed. The influence of different formulation factors like choice of enteric polymer, triethyl citrate (TEC) concentration (plasticizer), talc concentrations (anti-tacking agent), and different coating process parameters on the sealing performance of the capsule and the disintegration time were investigated. Furthermore, the influence of different disintegration test methods (with disc vs. without disc and 50 mM U.S. Pharmacopoeia (USP) buffer pH 6.8 vs. biopredictive 15 mM phosphate buffer pH 6.5) was evaluated. All formulations showed sufficient but not equivalent acid resistance when tested. Polymer type was the main f…
Novel solutions for closed-loop Reverse Electrodialysis: thermodynamic characterisation and perspective analysis
2019
Abstract Closed-loop Reverse Electrodialysis is a novel technology to directly convert low-grade heat into electricity. It consists of a reverse electrodialysis (RED) unit where electricity is produced exploiting the salinity gradient between two salt-water solutions, coupled with a regeneration unit where waste-heat is used to treat the solutions exiting from the RED unit and restore their initial composition. One of the most important advantages of closed-loop systems compared to the open systems is the possibility to select ad-hoc salt solutions to achieve high efficiencies. Therefore, the properties of the salt solutions are essential to assess the performance of the energy generation a…
Prediction of Maxwell – Stefan diffusion coefficients in polymer – multicomponent fluid systems
2014
Abstract Calculations of mass fluxes in multicomponent fluids based on the system of generalized Maxwell–Stefan equations (GMSE) is preferably used because Maxwell–Stefan (M–S) diffusion coefficients are symmetrical and have a clear physical meaning, as they reflect the binary friction forces between compounds in the system. For the calculation of the mass transport of a multicomponent fluid in the polymer basing on GMSE, it is necessary to have M–S diffusion coefficients. This paper proposes a method that allows their calculation using widely available self-diffusion coefficients and binary diffusion coefficients for infinitely diluted mixtures. The proposed method was compared with the me…
Phase equilibria in the ternary system isobutyl alcohol+isobutyl acetate+1-hexanol and the binary systems isobutyl alcohol+1-hexanol, isobutyl acetat…
2005
Abstract Consistent vapor–liquid equilibrium (VLE) data at 101.3 kPa have been determined for the ternary system isobutyl alcohol (IBA) + isobutyl acetate (IBAc) + 1-hexanol and two constituent binary systems: IBA + 1-hexanol and IBAc + 1-hexanol. The IBA + 1-hexanol system exhibits no deviation from ideal behaviour and IBAc + 1-hexanol system show lightly positive deviation from Raoult's law. The activity coefficients of the solutions were correlated with its composition by the Wilson, NRTL, UNIQUAC models. The ternary system is well predicted from binary interaction parameters. 1-Hexanol eliminates the IBA–IBAc binary azeotrope. However, the change of phase equilibria behaviour is small t…
Phase equilibria in the systems isobutyl alcohol+N,N-dimethylformamide, isobutyl acetate+N,N-dimethylformamide and isobutyl alcohol+isobutyl acetate+…
2005
Abstract Consistent vapor–liquid equilibria (VLE) were determined for the ternary system isobutyl alcohol (IBA) + isobutyl acetate (IBAc) + N,N-dimethylformamide (DMF) and two constituent binary systems at 101.3 kPa. The IBA + DMF system exhibits negative deviation from ideal behaviour and IBAc + DMF system deviates positively from ideal behaviour. The activity coefficients of the solutions were correlated with its composition by the Wilson, NRTL and UNIQUAC models. The ternary system is well predicted from binary interaction parameters.
Vapor–liquid equilibria in the ternary system isobutyl alcohol+isobutyl acetate+butyl propionate and the binary systems isobutyl alcohol+butyl propio…
2005
Abstract Consistent vapor–liquid equilibrium (VLE) data at 101.3 kPa have been determined for the ternary system isobutyl alcohol (IBA) + isobutyl acetate (IBAc) + butyl propionate (BUP) and two constituent binary systems: IBA + BUP and IBAc + BUP. The IBA + BUP system show lightly positive deviation from Raoult's law and IBAc + BUP system exhibits no deviation from ideal behaviour. The activity coefficients of the solutions were correlated with its composition by the Wilson, NRTL, UNIQUAC models. The ternary system is very well predicted from binary interaction parameters. BUP eliminates the IBA–IBAc binary azeotrope. The change of phase equilibria behaviour is significant therefore this s…
Phase Equilibrium for the Esterification Reaction of Acetic Acid + Butan-1-ol at 101.3 kPa
2007
In this work, the thermodynamic behavior of catalytic esterification reaction equilibrium and vapor–liquid equilibria (VLE) for the quaternary reactive system acetic acid + butan-1-ol + butyl acetate + water and constituent binary systems acetic acid + butyl acetate, butan-1-ol + butyl acetate, and butan-1-ol + water have been determined at 101.3 kPa, and liquid–liquid equilibria (LLE) of the binary system butan-1-ol + water have also been determined. The esterification reaction rate of the acetic acid and butan-1-ol mixture is very slow. So, in this study, p-toluenesulfonic acid was selected as the catalyst to accelerate the chemical reaction. The measured VLE data were correlated by the N…
Isobaric vapor–liquid equilibria for the binary systems isobutyl alcohol+isobutyl acetate and tert-butyl alcohol+tert-butyl acetate at 20 and 101.3kPa
2005
Abstract New consistent vapor–liquid equilibrium data for the binary systems isobutyl alcohol (IBA) + isobutyl acetate (IBAc) and tert-butyl alcohol (TBA) + tert-butyl acetate (TBAc) are reported at 20 and 101.3 kPa. The IBA + IBAc system, which deviates positively from ideal behavior, can be described as symmetric solution and presents azeotrope at both pressures. The TBA + TBAc system shows positive deviations from ideal behavior and presents azeotrope only at 20 kPa. The activity coefficients and boiling points of the solutions were correlated with their composition by the Wilson, UNIQUAC, NRTL and Wisniak–Tamir equations.
Effect of the basidiomycete Poria cocos on experimental dermatitis and other inflammatory conditions.
1997
The hydroalcoholic extract from P. cocos was examined for oral and topical anti-inflammatory activities. It proved to be active against carrageenan, arachidonic acid, tetradecanoyl phorbol acetate (TPA) acute edemas, TPA chronic inflammation and oxazolone delayed hypersensitivity in mice. Two lanostane-type triterpenes were isolated and identified by spectroscopic methods as dehydrotumulosic and pachymic acids. Their ID50 on acute TPA edema was 4.7 x 10(-3) and 6.8 x 10(-4) mumol/ear, respectively.