Dense flat-sheet membranes were prepared from poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) using the casting solvents chloroform and 1,1,2-trichloroethylene. X-ray diffraction, tapping mode atomic force microscopy (TM-AFM), and contact angle studies were used to characterize the membranes. The surface energy and the solubility parameters of the PPO membranes were determined from the measured co...

Gas chromatography used to calculate the specific retention volume of several hydrocarbons in different chromatographic liquid phases (Squalane, Carbowax-400, Carbowax-1500, Carbowax-4000, Amine220, Dinonyl phthalate, Tributyl phosphate and Trixylenyl phosphate). Some thermodynamic parameters, such as enthalpy of sorption and Flory-Huggins parameters relating the interaction between liquid phas...

Statins are mainly used as the inhibitors of enzyme 3-hydroxy-3 methyl glutaryl coenzyme A (HMG COA) reductase which is responsible for the synthesis of cholesterol. Apart from the cholesterol reducing activity they also facilitate as antiinflammatory and cardio-protective agents. Solubility is one of the main parameter for any drug to achieve the expected therapeutic effects. Since Simvastatin...

Sulfonamides are drugs extensively used for the treatment of certain infections caused by gram-positive and gram-negative microorganisms, some fungi, and certain protozoa. Several physical and chemical parameters of these compounds have been correlated with their chemotherapeutic activity: pK a , protein binding, and electronic charge distribution, among others. Unfortunately, no single paramet...

A series of basic carboxamides of actagardine (1), a lantibiotic possessing good antistreptococcal activity, were synthetized. Some physico-chemical characteristics, in particular charge and lipophilicity, that influence water solubility were determined. The in vitro and in vivo activity was evaluated. The monocarboxamides were generally more active than actagardine against selected Gram-positi...

The water solubility in fatty acid esters and biodiesels and the vapor–liquid equilibria (VLE) of fatty acid ester + methanol/ethanol systems, formed at biodiesel production and purification industrial units, were modeled in this work to complete the development and application of the soft-SAFT equation of state (EoS) to the design and optimization of biodiesel production plants. The soft-SAFT ...

barium sulfate (barite) is one of the widely used weighting materials in the preparation of drilling fluid for deep oil and gas wells. barite is not soluble in the regular solvents; such as, hydrochloric acid (hcl) and other acids. therefore, in this study, we focused on evaluating the dissolution of the industrial barite particles in different chelating agents. chelating agents; such as, dieth...

Phase transitions in constraint satisfaction problems (CSP's) are the subject of intense study. We identify a control parameter for random binary CSP's. There is a rapid transition in the probability of a CSP having a solution at a critical value of this parameter. This parameter allows diierent phase transition behaviour to be compared in an uniform manner, for example CSP's generated under di...

GAWRYS, KEITH LOUIS. How Asphaltenes Aggregate: Role of Chemistry and Solvent. (Under the direction of Peter K. Kilpatrick) Asphaltenes from three crude oils were separated on a preparatory-scale into 20 30 discrete subfractions by sequential precipitation from mixtures of n-heptane and toluene. The earliest fractions precipitated were characterized by lower than average aromaticity and atomic ...

The properties of a variety of mouth protectors and sheet materials used to fabricate custom mouth protectors were determined in order to recommend limits for a specification. Hardness, water sorption, water solubility, impact absorption, and tear strength were measured, and limits for these properties were suggested.