Relationship Between the Solubility Parameter and the Surface Free Energy of Some Solids

Solubility parameters for a number of drugs and related organic solids were determined from their dispersion and polar surface free energy data by means of an equation found to be valid for solvents. The relation fits quite well all solids investigated with an excellent correlation coefficient. The calculated solubility parameters, _O, were checked with the ones estimated from molecular groups and fragment constants according to Fedors method, _F. A similar _O of 14.6 was obtained for o-hydroxybenzoic and p-hgdroxybensoic acids. The deviations from _F shown in ethyl-p-aminobenzoate, benzoic acid, and aspirin were attributed to the imperfection of their vapor.

The solubility profile of hydrocortisone acetate was obtained in dioxane-water mixtures, and the solubility parameter of the drug was determined from the peak solubility in this binary solvent system. The experimental results for some drugs were compared with their solubility parameters calculated from the surface free energy data. Excellent agreement was found for hydrocortisone acetate, whereas griseofulvin and p-hydroxybenzoic agreed fairly. The “chameleonic” behavior of benzoic acid results in different experimental Solubility parameter, and the percentage deviation from _O ranged from 3.4-20.8. A deviation of 11.8% was obtained for ethyl-p-aminobenzoate and was attributed to the influence of its crystal structure which would account for its low _E value measured. The relation suggested was also applied to the dicarboxylic acids. The odd-even alteration seen in their melting points is not reflected on their solubility parameters. The high _O calculated for these acids were related to their elongated shape.     

Synthesis,Characterization and DFT-D Studies of 2-Aminoethoxycalix[4]resorcinarenes: A Novel Heterogeneous Organocatalyst

Catalysis Letters - The present article reports the synthesis of two novel supramolecular architectures, Phenyl(octa-2-aminoethoxy)calix[4]resorcinarene and...     

Recent Advances in Research on Polyphenols: Effects on Microbiota,Metabolism, and Health

Polyphenols have attracted huge interest among researchers of various disciplines because of their numerous biological activities, such as antioxidative, antiinflammatory, antiapoptotic, cancer chemopreventive, anticarcinogenic, and antimicrobial properties, and their promising applications in many fields, mainly in the medical, cosmetics, dietary supplement and food industries. In this review, the latest scientific findings in the research on polyphenols interaction with the microbiome and mitochondria, their metabolism and health beneficial effects, their involvement in cognitive diseases and obesity development, as well as some innovations in their analysis, extraction methods, development of cosmetic formulations and functional food are summarized based on the papers presented at the 13th World Congress on Polyphenol Applications. Future implications of polyphenols in disease prevention and their strategic use as prophylactic measures are specifically addressed. Polyphenols may play a key role in our tomorrow´s food and nutrition to prevent many diseases.     

Research on Hybrid Renewable Energy Systems with Fault Detection Technology

Early and accurate fault detection and diagnosis for renewable energy systems can increase their safety and ensure the continuity of their service. This paper presents a comprehensive review of different fault detection and diagnosis methods for hybrid renewable energy systems consisting of a wind turbine power generator, a PV （photovoltaic） array, a PEM （polymer electrolyte membrane） fuel cell and a battery storage system. The need of batteries to store the generated power from the solar panel, wind turbine or PEM fuel cell is also emphasized. Finally, an overview of the current methods used in the diagnosing of the lead-acid battery degradation is given.