6.3. A. Microemulsions (135-143) Microemulsions are clear, stable, isotropic mixtures of oil, water, and surfactant, frequently in combination with a cosurfactant 135-137. Microemulsions have several advantages such as enhanced drug solubility, good thermodynamic stability, and higher transdermal permeability over conventional formulations 138,139. Many studies reported the use of microemulsions as topical drug delivery vehicles showed their ability to improve transdermal and dermal delivery…
Esterification is a Nucleophilic Acyl Substitution Reaction wherein a carboxylic acid or a derivative of a carboxylic acid accepts a nucleophile which in turns substitutes for a leaving group. In esterification a leaving group connected to the carbonyl carbon is substituted by an alkoxide ion which forms the formula RCOOR’ which is an ester. For this particular experiment the esterification used was the Fischer esterification reaction which involves a carboxylic acid and an alcohol mixed in…
fuel resources such as coal, but we are getting religion. With the right amount of will and leadership we can certainly avoid the worst ' ' ' (Marsa 124). Australia has started to work on reforms to change their nasty habits such as putting a tax on carbon, which has provided an incentive to lower the usage of fossil…
In the Acid-Catalyzed Hydration of norbornene, water and sulfuric acid were added to the C=C double bond to form norborneol. Sulfuric acid acted as a catalyst, where it was not consumed in the reaction and helped to propel the reaction forward, as it was vital in forming hydronium ion and breaking the double bond. Both the products endo-norborneol and exo-norborneol were synthesized; however regioselectivity and stereoselectivity played a role as to which product was more preferred and whether…
goal of the OMCVD process, to produce zero-valent state of metal element with existing technology and producing units is only possible for the Ni(CO)4. The processes which apply other precursors usually produce the thin film of metal polluted by the carbon or…
Introduction 1.1 Polyurethane polyurethanes were first developed by Otto Bayer and coworkers in 1937. Shortly thereafter, Schollenberger and coworkers used formula modification to prepare elastomeric polyurethane products from Bayer's products that were like nylon or other engineering plastics in physical characteristics. PUs are widely used in coatings, flexible and rigid foams, elastomers, and composites. Reasons for the use of polyurethane coatings include: high performance characteristics…
In this study, we use the modified organo nanoclay as a new sorbent for separation and preconcentration trace amounts of Au(III) in aqueous solutions. Nanoclay was modified with 5-(4'-dimethylamino benzyliden)-rhodanine. Modified nanoclay was used as a solid sorbent for separation and preconcentration trace amounts of Au(III) ions. The sorption of gold ions was quantitative in pH range of 2.0 to 6.0, whereas quantitative desorption occurs instantaneously with 6.0 mL of 1.0 mol L-1 Na2S2O3. The…
Cyclohexene distillation A fraction containing primarily cyclohexene primarily cyclohexene and water is separated from raw cyclohexanone in Cyclohexene column. Raw Cyclohexanone is fed from storage tank to Cyclohexene Column via Cyclohexene heater. In Cyclohexene Heater, the feed is heated up to about 1200C with the heat carried by the bottom product from Alcohols column. The Cyclohexene column is operated at atmospheric pressure and temperatures of 850C at top and 1650C at bottom. The vapours…
staggered conformation,dihedral angle and a few more. Eclipsed conformation is the conformation whereby the C-H bonds on one carbon is directly aligned with the C-H bonds of the adjacent carbon. When the C-H bond of one carbon bisects the H-C-H bond on the adjacent carbon, it is known as staggered conformation. Dihedral angle is the angle which separates the the bond on carbon atom from another bond of the adjacent atom. The conformer is each possible structure of the isomerism. Conformational…
2. Materials and methods 2.1. Chemicals Zingerone was obtained from Alfa Aesar, Heysham, UK. Cisplatin, Bradford reagent, trichloroacetic acid (TCA), thiobarbituric acid (TBA), reduced glutathione (GSH), glacial metaphosphoric acid (Gmpa), 5,5ˊ-dithiobis-(2-nitrobenzoic acid) (DTNB), proteinase K and agarose were purchased from Sigma-Aldrich Co, MO, USA. All other chemicals and solvents used were of the highest purity grade available. 2.2. Animals Sixty Adult male albino rats (180-200g) were…