Transport processes in the sorption of colored ions by peat particles

A three-step model has been proposed for the adsorption of Astrazone Blue dye (Basic Blue 69) on peat. The initial rate of uptake of dye ions due to physical adsorption and chemisorption (ion exchange) has been correlated using a surface mass transfer coefficient. These coefficients have been determined and expressed in the dimensionless mass transfer form, Sh/Sc^0.33, as a function of agitation, initial dye concentration, peat particle size range, dye solution temperature, and mass of peat.     

Individually addressable submicron scale light-emitting devices based on electroluminescence of solid Ru(bpy)3(ClO4)2 films

A submicron light-emitting device (LED) was fabricated from lithographically fabricated parallel indium-tin oxide (ITO) finger electrodes (0.9 mum wide) separated by a 1.1 mum gap. A single layer of an amorphous (a) Ru(bpy)3(ClO4)2 film ( approximately 100 nm thick) was spin-coated on the electrode array. Ga:In or carbon paste was employed as a liftable upper contact electrode. Films ( approximately 1.5 mum thick) of single-crystal Ru(bpy)3(ClO4)2 (xyl) between two ITO electrodes in a sandwich cell were also prepared and produce electroluminescence. As with larger cells of this type, the high-resolution electroluminescence produced showed a high external efficiency ( approximately 3.4%), a low turn-on voltage (2.3 V), and reasonable stability. The single-crystal cells also behaved as photovoltaic devices and a short-circuit photocurrent was observed when they were irradiated without a bias voltage.     

The carbocyclic analog of cytidine,synthesis and antineoplastic activity

The carbocyclic analog (VI) of cytidine was prepared from the carbocyclic analog (I) of uridine. The intermediate stages were a tetrabenzoyl derivative of I, the tribenzoyl derivative of the uridine analog, and the tribenzoyl 4-chloropyrimidinone obtained from the latter derivative. The cytidine analog (VI) is active against KB cells in culture and against L1210 leukemia in mice. In the initial tests against L1210 leukemia, the highest dose (200 mg./kg./day, q.d. 1-9), of three active doses, increased lifespan by 82% and showed no evidence of toxicity.     

Destruction of carbonyl and hydroperoxide groups in oxidised polypropylene: Effect on photo-oxidation

The effect of destroying carbonyl and hydroperoxide groups in oxidised polypropylene on the subsequent rate of photo-oxidation has been examined using infra-red spectroscopy. The results show that carbonyl groups dominate the rate of photo-oxidation in severely oxidised polymer. In mildly oxidised polymer hydroperoxide groups control the rate, but to a much smaller extent. Destruction of the photo-active carbonyl and hydroperoxide groups in the unoxidised and oxidised polymers by prior photolysis in an inert atmosphere gave rise to some interesting and complex effects on subsequent photo-oxidation. The results indicate that although carbonyl and hydroperoxide groups may control the rates of photo-oxidation of thermally oxidised/processed polymer, their importance as primary photo-initiators is highly questionable. Oxygen-polymer charge transfer complexes appear to be the more likely photo-initiators.