XRD and SEM Investigation of Swift Heavy Ion-Irradiated Polyvinylidene Fluoride Thin Films

Polyvinylidene fluoride (PVDF) films of different thicknesses are irradiated with 100 meV Ag-ion and 75 meV Oxygen-ion beams at different fluences to study the effects of swift heavy ion (SHI) irradiation in PVDF. The change in physical, chemical, and surface morphological properties of irradiated films are investigated using x-ray diffraction, Field emission scanning electron microscopy (FESEM), and energy dispersive analysis by x-ray (EDAX) techniques by taking unirradiated (pristine) films as reference. The diffraction pattern shows that PVDF polymer is in semi-crystalline form and possesses crystalline α-, β-, and γ-phases. A decrease in the crystallinity and crystallite size has been observed when PVDF is irradiated with 100 meV Ag-, and also Oxygen ions at a higher fluence of 5.675 × 10¹² ions/cm². However, an increase in crystallinity and decrease in crystallite size are observed when PVDF is irradiated with oxygen-ion beam at lower fluence 5.625 × 10¹¹ ions/cm². The structural parameters such as degree of crystallinity, crystallite size, microstrain, and dislocation density have also been estimated. EDAX result shows that the chemical composition of PVDF is invariant under SHI irradiation, which is in agreement with our earlier results of FTIR. FESEM analysis shows granular microstructure with small porosity on SHI irradiation.     

In Vitro Antimicrobial Effect of Encapsulated Vancomycin on Internalized Staphylococcus aureus Within Endothelial Cells

ABSTRACT

Vancomycin (VCN) is a glycopeptide antibiotic that is effective in the treatment of gram-positive bacterial infections, but mainly reserved for methicilin resistant Staphylococcus aureus. It is, however, ineffective against intracellular bacteria and hence a particulate form of VCN would be required. Bovine serum albumin (BSA) microspheres of VCN with a mean particle size of 5 ± 1.6 μm were used. Human microvascular endothelial cells internalized both S. aureus and VCN microspheres in a time and concentration-dependent manner, however, the uptake was inhibited by cytochalasin D. Action of VCN on S. aureus in the intracellular microenvironment decreased the bacterial load considerably.     

A new electrode reactor with in-built recirculation mode for the enhancement of methylene blue dye removal from the aqueous solution: Comparison of adsorption,electrolysis and combined effect

The removal of basic dye such as methylene blue (MB) dye from the synthetic wastewater was experimentally investigated using an electrolytic cell (EC), adsorption and the combined effect of EC and adsorption technology called a three-phase three-dimensional electrode reactor (TPTDER). The performance of the each technology was checked on the basis of the efficiency of the systems. The experimental results are expressed in terms of the removal efficiency of the dye molecules. The results show that the TPTDER could efficiently remove the dye molecules from the aqueous solutions when compared with the EC and adsorption process. The removal efficiency reached as high as about 99% for an initial MB dye concentration in the range of 100–1,000 mg/L by TPTDER for 10 min at 12 V cell voltage and at specific airflow conditions. It was also observed that the removal of dye molecules depends upon the initial solution pH, applied cell voltage, contact time, and initial dye concentration. The recyclability of the particle electrodes in the TPTDER process was also checked. These findings suggest that TPTDER is a promising technology for the removal of dyes from the aqueous solution, and can be applied to the removal of dyes from the industrial effluents.     

Deposition and characterization of electroless Ni-Co-P alloy for diffusion barrier applications

Electroless deposited NiP and NiCoP thin films were studied for their diffusion barrier properties for copper wiring in ultra-large scale integration (ULSI) technology. The thermal stability of the Si/NiP/Cu and Si/NiCoP/Cu structures was evaluated by X-ray diffractometer (XRD), four probe method and field emission-scanning electron microscope (FE-SEM). Results indicated that both structures, i.e. Si/NiP/Cu and Si/NiCoP/Cu are thermally stable up to 500 °C. Further annealing results in formation of various silicided phases.     

Evaluating a Probabilistic Approach for Simulating Pathogen Removal at a Riverbank Filtration Site in India

In this paper, concentrations of pathogens in the influent and bank filtrate water at a riverbank filtration (RBF) site in Haridwar, India, are simulated by using a probabilistic approach. During the study of the RBF water quality in Haridwar in 2005–2006, it was observed that the river water does not meet World Health Organization and other Bureau of Indian Standards requirements for drinking water quality, especially with respect to bacteriological water quality, i.e., total coliform and fecal coliform levels, and therefore, changes to the river water quality as it moves to an infiltration well are of much relevance. By using the river water quality and the quality of abstracted water from nearby pumping wells, a probabilistic approach is used to study the variation of probability of clogging under different bacteriological qualities of source water. It is observed that the probability of clogging the pores varies with the natural logarithm of the concentrations of pathogens in source water, and the probabilistic approach has the potential to be used to simulate variations in pathogens in riverbank filtrate.     

Analysis of consecutive k-out-of-n: F systems with single repair facility

In this paper, a consecutive k-out-of-n:F system with non-identical units and with a single repair facility is analyzed in connection with the reliability and availability of the system. The failure rates of the units are constant and the repair time is arbitrarily distributed. A mathematical model is developed using semi-regenerative phenomena and systems of convolution integral equations satisfied by various state probabilities corresponding to different initial conditions are obtained. A particular case with k = 2 and n = 3 is analyzed numerically to study the effect of various parameters on the availability and reliability of the system.     

Adoptive immunotherapy of murine lymphosarcoma: comparative study using allo-immune or tumor-immune T cells

The antitumor effect of allosensitization with lymphocytes and skin graft of DBA/2 mice was evaluated using immunogeneic, transplantable Lymphosarcoma (LS-A) syngeneic to Swiss mice. A dose dependent tumor inhibitory effect in terms of tumor free mice was observed in mice sensitized i.p. with lymphocyte doses between 10-100 million per animal. Sensitization with allogeneic primary skin graft was more effective than lymphocyte immunization. The antitumor immunity could be adoptively transferred in syngeneic Swiss mice using either allo-immune or tumor-immune T cells. Analysis of T cell phenotypes using monoclonal antibodies against cell surface markers CD4 and CD8, indicated absolute dependence on the CD4+ T cells subset in tumor cure in case of allo-immune as well as tumor-immune T cells. CD8+ T cell subset was found essential only in case of allo-immune T cell therapy. Immunosuppression of mice with whole body gamma irradiation (4 Gy), 6 hr before transfer of allo-immune or tumor-immune T cells did not abrogate the therapeutic ability of allo-immune or tumor-immune T cells. Our results suggest that allosensitization could be an effective method of generating effector lymphocyte populations that might be used to treat tumors that exhibit detectable immunogenecity.