Solid–liquid equilibria measurements for binary systems comprising (butyric acid+propionic or pentanoic acid) and (heptanoic acid+propionic or butyric or pentanoic or hexanoic acid)

2013 ◽  
Vol 57 ◽  
pp. 485-492 ◽  
Author(s):  
Margreth Tadie ◽  
Indra Bahadur ◽  
Prashant Reddy ◽  
Peterson Thokozani Ngema ◽  
Paramespri Naidoo ◽  
...  
Keyword(s):  
Butyric Acid ◽  
Binary Systems ◽  
Hexanoic Acid ◽  
Heptanoic Acid ◽  
Pentanoic Acid ◽  
Solid Liquid

scholarly journals Solubility of Anthraquinone Derivatives in Supercritical Carbon Dioxide: New Correlations

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 460
Author(s):  
Ratna Surya Alwi ◽  
Chandrasekhar Garlapati ◽  
Kazuhiro Tamura
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Supercritical Carbon Dioxide ◽  
Binary Systems ◽  
Relative Deviation ◽  
Anthraquinone Derivatives ◽  
New Models ◽  
Solubility Isotherms ◽  
Solid Liquid ◽  
Supercritical Carbon

Solubility of several anthraquinone derivatives in supercritical carbon dioxide was readily available in the literature, but correcting ability of the existing models was poor. Therefore, in this work, two new models have been developed for better correlation based on solid–liquid phase equilibria. The new model has five adjustable parameters correlating the solubility isotherms as a function of temperature. The accuracy of the proposed models was evaluated by correlating 25 binary systems. The proposed models observed provide the best overall correlations. The overall deviation between the experimental and the correlated results was less than 11.46% in averaged absolute relative deviation (AARD). Moreover, exiting solubility models were also evaluated for all the compounds for the comparison purpose.

scholarly journals Establishment of a Gastric Cell-Based Assay System for Exploring Inhibitors of Octanoylated Ghrelin Production

2013 ◽  
Vol 18 (9) ◽  
pp. 1035-1042 ◽  
Author(s):  
Shigeru Oiso ◽  
Miyuki Nobe ◽  
Yuhei Yamaguchi ◽  
Shigeru Umemoto ◽  
Kazuo Nakamura ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Butyric Acid ◽  
Posttranslational Modification ◽  
Culture Medium ◽  
Octanoic Acid ◽  
Assay System ◽  
Heptanoic Acid ◽  
Ags Cells ◽  
Gastric Cell ◽  
Low Levels

Ghrelin, a gastric hormone, is a growth hormone-releasing peptide. Its serine-3 acylation with octanoic acid is essential for its orexigenic activity, and therefore, inhibition of the acylation of ghrelin may help in decreasing appetite and preventing obesity. This study aimed to establish a human gastric cell-based assay system to evaluate candidate inhibitors of octanoylated ghrelin production. In human gastric carcinoma AGS cells, obligatory factors for the posttranslational modification of ghrelin, such as certain prohormone convertases responsible for processing of proghrelin to the mature ghrelin and the enzyme-catalyzing acyl-modification of ghrelin, were well expressed, but ghrelin was expressed at low levels. Accordingly, we transfected a ghrelin-expressing vector into AGS cells and isolated a stable ghrelin-expressing cell line (AGS-GHRL8). AGS-GHRL8 cells secreted octanoylated ghrelin in accordance with the concentrations of octanoic acid in the culture medium. Given that ingested heptanoic acid is used for the acyl-modification of ghrelin, we evaluated whether heptanoic acid inhibits production of octanoylated ghrelin in AGS-GHRL8 cells. Butyric acid was used as a control. Indeed, heptanoic acid predictably decreased the secretion of octanoylated ghrelin, whereas butyric acid did not. The AGS-GHRL8 line established in this study will facilitate the screening of inhibitors of octanoylated ghrelin production.

scholarly journals Effect of Cation Structure in Quinolinium-Based Ionic Liquids on the Solubility in Aromatic Sulfur Compounds or Heptane: Thermodynamic Study on Phase Diagrams

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5687
Author(s):  
Marta Królikowska ◽  
Marek Królikowski ◽  
Urszula Domańska
Keyword(s):  
Ionic Liquids ◽  
Phase Diagrams ◽  
Binary Systems ◽  
Ambient Pressure ◽  
Equilibrium Phase ◽  
Sulfur Compounds ◽  
Solution Temperature ◽  
Organic Sulfur Compounds ◽  
Nrtl Equation ◽  
Solid Liquid

Experimental and theoretical studies on thermodynamic properties of quinolinium-based ionic liquids (ILs) based on bis(trifluoromethylsulfonyl)imide anion (namely N-butyl-quinoloinium bis(trifluoromethylsulfonyl)imide, [BQuin][NTf2], N-hexylquinoloinium bis(trifluoromethyl-sulfonyl)imide, [HQuin][NTf2], and N-octylquinoloinium bis(trifluoromethyl-sulfonyl)imide, [OQuin][NTf2]) with aromatic sulfur compounds and heptane, as a model compound of fuel were examined in order to assess the applicability of the studied ionic liquids for desulfurization of fuels. With this aim, the temperature-composition phase diagrams of 13 binary mixtures composed of organic sulfur compounds (thiophene, benzothiophene, or 2-methylthiophene) or heptane and ionic liquid (IL) were investigated at ambient pressure. A dynamic method was used to determine the (solid–liquid) equilibrium phase diagrams in binary systems over a wide composition range and temperature range from T = 255.15 to 365.15 K up to the fusion temperature of ILs. The immiscibility gap with an upper critical solution temperature (UCST) was observed for each binary system under study. The influence of the alkane chain length of the substituent on the IL cation and of the sulfur compounds (the aromaticity of the solvent) was described. The experimental (solid + liquid) phase equilibrium dataset were successfully correlated using the well-known NRTL equation.

scholarly journals The boundary integral theory for slow and rapid curved solid/liquid interfaces propagating into binary systems

2018 ◽  
Vol 376 (2113) ◽  
pp. 20170218 ◽  
Author(s):  
Peter K. Galenko ◽  
Dmitri V. Alexandrov ◽  
Ekaterina A. Titova
Keyword(s):  
Binary Systems ◽  
Computational Modelling ◽  
Selection Criterion ◽  
Type Equation ◽  
Boundary Integral ◽  
Boundary Integral Method ◽  
Isotropic Case ◽  
Liquid Interfaces ◽  
Stationary Growth ◽  
Solid Liquid

The boundary integral method for propagating solid/liquid interfaces is detailed with allowance for the thermo-solutal Stefan-type models. Two types of mass transfer mechanisms corresponding to the local equilibrium (parabolic-type equation) and local non-equilibrium (hyperbolic-type equation) solidification conditions are considered. A unified integro-differential equation for the curved interface is derived. This equation contains the steady-state conditions of solidification as a special case. The boundary integral analysis demonstrates how to derive the quasi-stationary Ivantsov and Horvay–Cahn solutions that, respectively, define the paraboloidal and elliptical crystal shapes. In the limit of highest Péclet numbers, these quasi-stationary solutions describe the shape of the area around the dendritic tip in the form of a smooth sphere in the isotropic case and a deformed sphere along the directions of anisotropy strength in the anisotropic case. A thermo-solutal selection criterion of the quasi-stationary growth mode of dendrites which includes arbitrary Péclet numbers is obtained. To demonstrate the selection of patterns, computational modelling of the quasi-stationary growth of crystals in a binary mixture is carried out. The modelling makes it possible to obtain selected structures in the form of dendritic, fractal or planar crystals. This article is part of the theme issue ‘From atomistic interfaces to dendritic patterns’.

Sign in / Sign up

Export Citation Format

Share Document