Preparation and characterization of novel semi‐interpenetrating 2‐hydroxyethyl methacrylate‐g‐chitosan copolymeric microspheres for sustained release of indomethacin

A novel semi‐interpenetrating (semi‐IPN) graft copolymer of 2‐hydroxyethyl methacrylate (HEMA) with chitosan (CS) has been prepared in the form of microspheres, using water‐in‐oil (W/O) emulsion technique. Microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X‐ray diffractometry (X‐RD) to confirm the crosslinking and polymorphism of indomethacin (IDM). The X‐RD and DSC techniques indicated a molecular‐level dispersion of IDM in the IPN matrix. Scanning electron micrographs (SEM) taken at the cross section of the microspheres have shown rough surfaces around the microspheres. The sustained release characteristics of the matrices for IDM, an anti‐inflammatory drug, were investigated in pH 7.4 media. Particle size and size distribution of the microspheres were studied by laser light diffraction particle size analyzer. The drug was released in a sustained manner for up to 12 h. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Vernolic acid intabebuia argentia seed oil: A moderate source of oil

Tabebuia argentia, Britt, Syn.Tkcoma argentia, Burr and Schum, belonging to the Bignoniaceae plant family, contains palmitic (21.7%), stearic (3.8%), oleic (9.8%), linoleic (52.7%), linolenic (3.0%) and vernolic (9.0%) acids. These fatty acids were characterized by infrared (IR), nuclear magnetic resonance (NMR), mass spectrometry (MS), gas-liquid chromatography (GLC) and chemical degradations. To whom correspondence should be addressed.     

Cassia siamea seed oil: A minor source of vernolic and cyclopropenoid fatty acids

Cassia siamea oil contains plamitic (19.0%), stearic (7.6%), oleic (11.6%), linoleic (42.7%), malvalic (2.0%), sterculic (3.1%) and vernolic (14.0%) acids.     

Cyclopropenoid fatty acids in leguminosae oils

Seed oils ofCassia grandis, Linn andDelonix elata, Gamble, Syn.Poinciana elata, Linn, belonging to the Leguminosae family contain small amounts of sterculic and malvalic acids as determined by conversion of esters with AgNO₃/MeOH, NMR and IR.     

Influence of Combined Addition of Boron and Strontium on High-Temperature Wear Behavior of A356 Alloy

In the present study, the effect of the combined addition of boron (B) and strontium (Sr) on the high-temperature dry sliding wear behavior of A356 alloy has been investigated using a pin-on-disc wear testing machine attached with a furnace. During wear studies, the effect of alloy composition, normal pressure, sliding speed, and sliding distance on A356 alloy at four temperatures, namely, room temperature and 100, 200, and 300°C, have been investigated. Further, the cast alloys and worn surfaces of A356 alloy with and without B and Sr were characterized by scanning electron microscopy (SEM)/energy-dispersive spectroscopy (EDS) microanalysis. Results indicate that the combined addition of B and Sr to A356 alloy has led to improvements in wear properties. This is due to a change in microstructure, improvement in mechanical properties, and the formation of an oxide layer between the mating surfaces during the sliding wear process.     

A minor source of vernolic,malvalic, and sterculic acids inPithecollobium dulce (syn.Inga dulcis) seed oil

Pithecollobium dulce, Benth (syn.Inga dulcis, Willd) seed oil, belonging to the Leguminosae plant family, contains minor amounts of vernolic acid (12,13-epoxy-octadec-cis-9-enoic acid, 10.0%), malvalic acid [7-(2-octacyclopropen-1-yl)heptanoic acid, 3.2%], and sterculic acid [8-(2-octacyclopropen-1-yl)octanoic acid, 2.0%]. The other normal fatty acids are palmitic (12.1%), stearic (4.2%), behenic (10.6%), oleic (34.1%), and linoleic (23.8%). These fatty acids have been characterized by Fourier transform infrared,¹H nuclear magnetic resonance, mass spectrometry and gas-liquid chromatography techniques and by chemical degradations.     

Effect of oxides on the reaction kinetics during hot-dip galvanizing of high strength steels

Selective oxidation of the minor alloying elements during annealing prior to hot-dip galvanizing cause poor wetting with liquid zinc, resulting in bare spot defects. The effect of surface coverage, morphology (i.e., size and distribution) of the oxides on the reaction kinetics was examined. The Zn wettability has been determined by sessile drop contact angle measurement method and the Fe–Al interfacial layer was investigated by the use of a novel hot temperature spinning process. It has been found that besides the overall surface oxide coverage, size of the oxide islands is a dominant factor in affecting the reaction kinetics.