Degradation in polytetrafluoro ethylene by 62 mev protons

The aim of our study is to describe the dose dependent proton induced modifications in Polytetrafluoro ethylene (PTFE) by using Fourier Transform Infra-red spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and X-ray diffraction analysis (XRD). The shifting of the main peak along with a decrease in its intensity, the decrease in thermal stability and melting point and the formation of stable free radicals were observed in the polymer by proton irradiation.     

A novel technique to measure the sucrose concentration in hydrogel sucrose solution using two dimensional photonic crystal structures

We propose a novel technique to measure the concentration of sucrose in PAm-hydrogel sucrose solution using two dimensional photonic crystal structures consists of air holes. PAm-hydrogel is an organic hydrogels, which is used as biomedical applications. The principle of measurement is based on the linear variation of photonic band gap with the change of dielectric constant of the solution infiltrated in air holes of photonic crystal structure. Plane wave expansion method is used to find the band gap and linear variation (R² = 0.9949) of photonic band gap with respect to sucrose concentration is observed. Besides this, an excellent linear variation (R² = 0.9949) of transmitted intensity of light with respect to sucrose concentration is also seen. Since the simulation is based on optical principle, it gives accurate results. This suggests the possible use of 2-D photonic crystal structure as a sucrose sensor. Experimental procedure for measuring the concentration of sucrose is also mentioned.     

Influence of the microstructure and its stability on the electrochemical properties of EMD produced from a range of precursors

The influence of the microstructure and the stable crystal structure on the electrochemical properties of the electrolytic manganese dioxide (EMD) produced from manganese cake (EMD_MC), low-grade manganese ore (EMD_LMO), and synthetic manganese sulfate solutions (EMD_SMS) is reported. X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry/differential thermal analysis, field emission scanning electron microscopy (FESEM), and chemical analyses were used to determine the structural and chemical characteristics of the EMD samples. The charge–discharge profile was studied in 9 M KOH using a galvanostatic charge–discharge unit. All the samples were found to contain predominantly γ-phase MnO₂, which is electrochemically active for energy storage applications. FESEM images show that preparation method significantly influences surface morphology, shape, and size of the EMD particles. In almost all cases, nanoparticles were obtained, with spindle-shaped nanoparticles for EMD_MC, platy nanoparticles in the case of EMD_LMO, and anisotropic growth of tetra-branched star-like nanoparticles of EMD_SMS. These nanoparticles arrange themselves in a near net-like fashion, resulting in porosity of the flakes of EMD during electrochemical deposition. Thermal studies showed loss of structural water and formation of lower manganese oxides. The EMD_MC showed superior discharge capacity of ~280 mAh g^?1 as compared to EMD_LMO (275 mAh g^?1) and EMD_SMS (245 mAh g^?1).     

Studies on Vinyl Polymerization: Polymerization of Methyl Methacrylate by Permanganate-Malonic Acid Initiator System

Aqueous polymerization of methyl methacrylate initiated by the permanganate-malonic acid redox pair has been studied under atmospheric conditions in the temperature range of 35 to 45°C. The effect of monomer, permanganate, and malonic acid concentrations and temperature on the rate of polymerization was studied. The effect of various water-soluble salts and solvents has been investigated. The rate of polymerization of the permanganate-malonic acid system was compared with the rates involved in various other systems consisting of oxalic acid, citric acid, and tartaric acid coupled with permanganate under similar conditions. The end-group of the polymer has been characterized by IR spectra. A suitable kinetic scheme has been proposed, and appropriate rate expressions have been derived on this basis and explained in the light of experimental findings.     

Direct detection of structurally resolved dynamics in a multiconformation receptor-ligand complex

Structure-based drug design relies on static protein structures despite significant evidence for the need to include protein dynamics as a serious consideration. In practice, dynamic motions are neglected because they are not understood well enough to model, a situation resulting from a lack of explicit experimental examples of dynamic receptor-ligand complexes. Here, we report high-resolution details of pronounced ~1 ms time scale motions of a receptor-small molecule complex using a combination of NMR and X-ray crystallography. Large conformational dynamics in Escherichia coli dihydrofolate reductase are driven by internal switching motions of the drug-like, nanomolar-affinity inhibitor. Carr-Purcell-Meiboom-Gill relaxation dispersion experiments and NOEs revealed the crystal structure to contain critical elements of the high energy protein-ligand conformation. The availability of accurate, structurally resolved dynamics in a protein-ligand complex should serve as a valuable benchmark for modeling dynamics in other receptor-ligand complexes and prediction of binding affinities.     

On some new type generalized difference sequence spaces

In this paper we introduce a new type of difference operator Δ _m ⁿ for fixed m, n ∈ ℕ. We define the sequence spaces ℓ_∞(Δ _m ⁿ ), c(Δ _m ⁿ ) and c ₀(Δ _m ⁿ ) and study some topological properties of these spaces. We obtain some inclusion relations involving these sequence spaces. These notions generalize many earlier existing notions on difference sequence spaces.