Visible light-mediated photocatalyzed synthesis of oxazole via intermolecular C?N and C?O bond formation

An efficient visible light-mediated, eosin Y-catalyzed synthesis of oxazole has been developed from benzil with primary amines, that providing a straightforward, green, and environmentally benign access to a wide variety of substituted oxazole-2-amines under mild reaction conditions.     

Morphological effects on mechanical properties of polystyrene-polyvinylchloride blends

The morphological effects on mechanical properties of polystyrene/polyvinylchloride (PS/PVC) polymer blends were investigated through dynamic mechanical analyzer. Study reveals that the peaks of Tan δ curves of pure PVC and pure PS samples fall at temperatures 58.9 ± 0.2°C and 113.1 ± 0.1°C, respectively. Tan δ curves of 30, 50 and 70-wt% of PVC blends show two peaks indicating the immiscibility of PS/PVC blend. It has been observed that peak falling at lower temperature side shifts towards the higher temperature with the increase of PS concentration and the other one which falls at higher temperature side shifts towards lower temperature side with the increase of PVC concentration in PS/PVC blends. The variation in mechanical performance is attributed to the polymer domain interactions resulting from the different morphologies of various blend compositions.     

Morphology,miscibility and mechanical properties of PMMA/PC blends

This study deals with some results on morphology, miscibility and mechanical properties for polymethyl methacrylate/polycarbonate (PMMA/PC) polymer blends prepared by solution casting method at different concentration between 0 and 100 wt%. Dynamic storage modulus and tan δ were measured in a temperature range from 30 to 180°C using dynamical mechanical analyzer (DMA). The value of the storage modulus was found to increase with the addition of the PC in the matrix. Transition temperature of pure PMMA and pure PC is found to be 83.8 and 150°C, respectively. The result shows that the two polymers are miscible for whole concentration of PC in PMMA. The distribution of the phases in the blends was studied through scanning electron microscopy (SEM). Also the mechanical properties like elongation at break and fracture energy of the PMMA/PC blends increase with the increase in concentration of PC in PMMA.     

High speed,long reach OFDM-FSO transmission link incorporating OSSB and OTSB schemes

Free Space Optics (FSO) link is extremely responsive to the diverse climate state of affairs that bound the FSO range. A demonstration of fading resistant FSO system using a simulated test-bed employing OFDM scheme is reported in this work to realize the prolonged FSO link with acceptable SNR and BER with the highest stream rate of 5 Gb ps under the impact of diverse weather conditions. Simulations point toward that the proposed hybrid OFDM-FSO transmission system incorporating OTSB- and OSSB-schemes promises significantly enhanced FSO link compared to conventional FSO systems.     

Dendrimer building toolkit: Model building and characterization of various dendrimer architectures

We have developed a graphical user interface based dendrimer builder toolkit (DBT) which can be used to generate the dendrimer configuration of desired generation for various dendrimer architectures. The validation of structures generated by this tool was carried out by studying the structural properties of two well known classes of dendrimers: ethylenediamine cored poly(amidoamine) (PAMAM) dendrimer, diaminobutyl cored poly(propylene imine) (PPI) dendrimer. Using full atomistic molecular dynamics (MD) simulation we have calculated the radius of gyration, shape tensor and monomer density distribution for PAMAM and PPI dendrimer at neutral and high pH. A good agreement between the available simulation and experimental (small angle X‐ray and neutron scattering; SAXS, SANS) results and calculated radius of gyration was observed. With this validation we have used DBT to build another new class of nitrogen cored poly(propyl ether imine) dendrimer and study it's structural features using all atomistic MD simulation. DBT is a versatile tool and can be easily used to generate other dendrimer structures with different chemistry and topology. The use of general amber force field to describe the intra‐molecular interactions allows us to integrate this tool easily with the widely used molecular dynamics software AMBER. This makes our tool a very useful utility which can help to facilitate the study of dendrimer interaction with nucleic acids, protein and lipid bilayer for various biological applications. © 2012 Wiley Periodicals, Inc.     

On $\Psi$-projective expansion, quasi partial metrics aggregation with an application

In the present article, the notion of expansion between quasi partial metric spaces through aggregation is defined. With the help of aggregation functions, the concept of projective $\Psi$-expansion is introduced and some fixed point results are obtained through this notion. Furthermore, sufficient conditions are provided to characterize aggregation function and to ensure the existence and uniqueness of fixed point. All the results presented in this paper are new and an application to asymptotic complexity analysis is also given after the results.     

Methyltrioxorhenium catalyzed aerobic oxidation of organonitrogen compounds

A variety of tertiary, secondary and primary organonitrogen compounds have been efficiently and selectivity oxidized to their corresponding N-oxides, nitrones, and nitro compounds with molecular oxygen using methyltrioxorhenium as catalyst.     

Electrical and compositional properties of TaSi2 films

Tantalum silicide (TaSi₂) thin films were sputter deposited on p- and n-type silicon substrates using ultrapure TaSi₂ targets. The TaSi₂/Si samples were annealed in nitrogen or forming gas or oxygen containing steam at temperatures in the range of 400–900°C. The sheet resistances of TaSi₂/Si were measured by four-point probe before and after anneal. The structure of these films was investigated using x-ray diffraction (XRD) methods. It has been found that the sheet resistance decreases with the increase in annealing temperature and also with the increase in film thickness. X-ray diffraction patterns show changes in the morphological structure of the films. Oxidation characteristics of the film have been investigated in the temperature range of 400–900°C in oxygen containing steam ambient. The oxidation time ranged from 0.5 to 1.5 h. No oxide formation of the tantalum silicide films was observed in this investigation. This has been attributed to the high purity of TaSi₂ sputter targets used in the preparation of the films.     

Bromamine-T/RuCl3 as an efficient system for the oxidation of tertiary amines to N-oxides

A variety of tertiary amines were efficiently and selectively oxidized to the corresponding N-oxides by bromamine-T using ruthenium trichloride as catalyst in alkaline (pH 8.4) acetonitrile/water (1:1) at 80 °C.