Synthesis and biological activity of new β-lactam and thiazolidinones containing a sulphanilamide moeity

Some new sulpha drugs containing both β-lactam and/or thiazolidinone moieties have been prepared. The biological screening of the prepared compounds has been carried out on some strains of pathogenic bacteria. It is clear that these compounds have a different mechanism of action other than that already known for the sulpha drugs.     

A study of the optical absorption edge in silicate glasses containing TiO2 oxide

A detailed study of the optical absorption as a function of temperature and composition for a series of soda-lime-silica glasses doped with TiO₂ oxide is presented. The variations of the optical energy gap with temperature in the range 296 to 483 K are reported. The UV results are analysed assuming optical absorption by indirect transitions. It was found from these optical absorption data that the present glass system can be divided into three compositional regions.     

Synthesis and antibacterial activity of some new diarylsulphides and diarylsulphones containing azetidin-2-one and/or diazetidin-2-onyl moities

Cyclonucleophilic addition of N-phthaloylaminoacid chlorides (II on 4-(N-ary-lideneamino)-4′-nitrodiphenyl sulphides (I) in dioxane and triethylamine afforded 4-(4″-aryl-3″-phthalylamino-2″-oxo-azetidin-1″-yl)-4′-nitro-diphenyl sulphides (III). Hydrazinolysis of III yielded 4-(4″-aryl-3″-amino-2″-oxo-azetidin-1″-yl)-4′-nitro-diphenyl sulphide hydrochlorides (IV). Condensation of IV with anisaldehyde using ethanol and piperidine as a basic catalyst gave 4-(4″-aryl-3″-anisylidine amino-2″-oxoazetidin-1″-yl)-4′-nitrodiphenylsulphides (V) in good yields. Interaction of V with chloroacetyl chloride in dioxane and triethylamine produced 4-(4″-aryl-3″-substituted β-lactamyl-2″-oxo-azetidin-1″-yi)-4′-nitrodiphenyl sulphides VI. Oxidation of IV, V and VI using hydrogen peroxide/glacial acetic acid mixtures gave the corresponding sulphones (VII), (VIII) and (IX). Sulphones of the type IX were obtained by unequivocal synthesis through interaction of sulphone-anils VIII with chloroacetyl chloride. The antibacterial activities of some of these compounds were determined.     

Einfluß von Silicium auf das Perlitwachstum eutektoidischer Stähle

Metallographische Untersuchungen zur Ermittlung der Perlitwachstumsgeschwindigkeit in einem Stahl mit 2% Si im Vergleich zu einem unlegierten eutektoidischen Stahl hoher Reinheit. Ermittlung der Ae₁-Temperatur und Erörterung der Versuchsergebnisse im Vergleich zu Schrifttumsangaben.     

A survey of vitamin A and D contents of fortified fluid milk in Ontario

High performance liquid chromatographic methods for measuring the concentration of vitamins A and D in fluid milk were validated and used to assess the level of these nutrients in Ontario retail milk samples. Thirteen and fifteen fortified milk samples were tested for vitamins A and D, respectively. Repeatability relative standard deviation values for vitamins A and D in milk were generally less than 10%. Recoveries varied from 87 to 107%. Vitamin D results indicated that only 20% of skim, 40% of 2% fat milk, and 20% of whole milk contained the recommended levels, whereas 46% of skim, and 77% of 2% fat milk had the required levels of vitamin A. The results indicate that vitamin level varies widely in Ontario retail milk.     

A scalable multicast routing protocol for building shortest path trees

Scalability is a great concern in the design of multicast routing protocols for the global Internet. Building shortest path trees (SPT) is currently one of the most widely used approaches to supporting multicast routing because of the simplicity and low per‐destination cost of such trees. However, the construction of an SPT typically involves high protocol overhead, which leads to the scalability problem as the number of concurrent multicast sessions increases. In this paper, we present a destination‐initiated shortest path tree (DSPT) routing protocol. The design objective is to effectively reduce the protocol overhead associated with SPT constructions for providing scalable multicast. To achieve this objective, we introduce destination‐initiated joining operations in constructing SPTs. With DSPT, each router receiving a request to join a specific multicast group makes a local decision on selecting its parent node through which it connects to the existing tree. A source‐rooted SPT is built as a result of such collaborative operations at nodes. DSPT requires only limited routing information at routers. Analytical results demonstrate that DSPT scales well with respect to computation, storage and communication overhead when the number of concurrent multicast requests is large. Simulation experiments are also conducted to verify the correctness of the theoretically deduced analytical results. Copyright © 2006 John Wiley & Sons, Ltd.     

Synthesis of Fe3O4/polyaniline nanocomposite and its application for nitrate removal from aqueous solutions

The aim of this work was to investigate the sorption characteristics of Fe₃O₄ coated on polyaniline (Fe₃O₄/PAn) for the removal of NO₃^? ions from aqueous solutions. The sorption of NO₃^? ions by the batch method was carried out. The optimum conditions of sorption were found to be a Fe₃O₄/PAn dose of 0.4 g in 100 mL of NO₃^? solution, a contact time of 10 min, pH and temperature 7 and 40°C, respectively. Temperature had a negative effect on the removal efficiency. Three equations, i.e., Morris–Weber, Lagergren, and pseudo‐second‐order, were tested to track the kinetics of the removal process. The Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models were subjected to sorption data in order to estimate sorption capacity, intensity, and energy. The thermodynamic parameters ΔH, ΔS, and ΔG were evaluated. They showed that the adsorption of NO₃^? onto Fe₃O₄/PAn was feasible, spontaneous, and exothermic under the studied conditions. It can be concluded that Fe₃O₄/PAn has potential to remove NO₃^? ions from aqueous solutions at different concentrations. The system Fe₃O₄/Pan was successfully tested for a high removal efficiency of NO₃^? from urban wastewater. J. VINYL ADDIT. TECHNOL., 19:147–156, 2013. © 2013 Society of Plastics Engineers