Study of 160 MeV Ni ion irradiation effects on electrodeposited polypyrrole films

Conducting polymer polypyrrole thin films doped with LiCF₃SO₃, [CH₃(CH₂)₃]₄NBF₄ and [CH₃(CH₂)₃]₄NPF₆ have been electrodeposited potentiodynamically on ITO coated glass substrate. The polymer films are irradiated with 160 MeV Ni¹²⁺ ions at three different fluences of 5 × 10¹⁰, 5 × 10¹¹ and 3 × 10¹² ions cm⁻². An increase in dc conductivity of polypyrrole films from 100 S/cm to 170 S/cm after irradiation with highest fluence is observed in four-probe measurement. X-ray diffractogram shows increase in the crystallinity of the polypyrrole films upon SHI irradiation, which goes on increasing with the increase in fluence. Absorption intensity increase in the higher wavelength region is observed in the UV–Vis spectra. The SEM studies show that the cauliflower like flaky microstructure of the surface of polypyrrole films turns globular upon SHI irradiation at fluence 5 × 10¹¹ ions cm⁻² and becomes smooth and dense at the highest fluence used. The cyclic voltammetry studies exhibit that the redox properties of the polypyrrole films do not change much on SHI irradiation.     

Atanassov’s intuitionistic fuzzy submodules with respect to a t-norm

In this paper, t-norm based intuitionistic fuzzy submodules are defined, and their various properties are investigated. We also show that if an intuitionistic fuzzy set of a module is an intuitionistic fuzzy submodule with respect to a t-norm, then it is also an intuitionistic fuzzy submodule with respect to the annihilation t-norm. We investigate the nature of intuitionistic fuzzy submodules of a module with the help of their respective cut sets. We obtain some results based on (α, β)-level sets and t-norm based α-cut sets of an intuitionistic fuzzy submodule with respect to a t-norm T.     

Controlled release of curcumin from thiolated starch-coated iron oxide magnetic nanoparticles: An in vitro evaluation

Thiolated starch-coated iron oxide nanoparticles containing curcumin were developed to investigate their cytotoxicity on lymphocytes and cancer cell lines. These nanoparticles were prepared using different concentrations of thiolated starch to study the effect of polymer coating on various properties of nanoparticles, namely, yield percentage, particle size, drug encapsulation, etc. Zeta potential confirmed the stability of nanoparticles. The nanoparticles with 5% polymer coating showed drug encapsulation efficiency up to 78%, while loading efficiency was higher than 80%. The cytotoxicity assay revealed excellent compatibility of the system with lymphocyte cells while considerable amount of cytotoxicity on cancer cell lines.     

Controlled radical polymerization of n-hexadecyl methacrylate mediated by tris(2,2′-bipyridine)iron(III) complexes

Poly(n-hexadecyl methacrylate) (PHMA) with narrow molecular weight distribution has been synthesized by atom transfer radical polymerization (ATRP) and reverse ATRP of n-hexadecyl methacrylate (HMA) at 80 °C in N, N-dimethylformamide (DMF) using the CBr₄/tris(2,2′-bipyridine)iron(III) complex initiation system in the presence of 2,2′-azobisisobutyronitrile (AIBN). From the kinetic studies and molecular weight data, it reveals the controlled nature of polymerization. The effect of various reaction parameters on number-average molecular weight (M _n ) and molecular weight distribution (M _w /M _n ) have been investigated. For the reverse ATRP, the catalyst tris(2,2′-bipyridine)iron(III)complex, [Fe(bpy)₃]³⁺, played an important role in polymerization rate and M _w /M _n . The resulting PHMA that obtained by reverse ATRP shows the best control of molecular weights and its distribution as compared to normal ATRP system. PHMA has been characterized by different techniques such as GPC, XRD and NMR spectroscopy.     

Carbonization of Eight Bamboo Species of Northeast India

Abstract

Eight bamboo species of northeast India were carbonized in a laboratory-scale fixed bed reactor at temperature ranging from 300°C to 600°C with a heating rate of 5°C/min, and their mass balance experiments of decomposition products were done at 600°C. At this temperature, the yields of charcoal, tar, gas, and condensable liquid ranged from 23.35–28.25%, 6.46–8.85%, 6.93–10.05%, and 51.98–57.96%, respectively. Fixed carbon content of the charcoal samples varied from 62.10–67.52% indicating their suitability only for domestic use or as a fuel for gasification and not for metallurgical use.     

Hollow ZnO from assembly of nanoparticles: photocatalytic and antibacterial activity

Hollow shells of ZnO were formed by the assembly of nanoparticles using PEG 400 wherein PEG-400 acted like both a solvent and a structure directing agent. The structure, morphology and optical properties were characterized by using PXRD, SEM, TEM and absorption studies. The hollow shells were found to possess high crystallinity with a surface area of 8 m² g^?1. The assembly was formed by nanoparticles ranging from 50 to 60 nm, whereas the size of the hollow shell ranged from 500 nm to 1 micron. Photocatalytic activity of these nanostructures was studied using Rhodamine B (RhB) and methyl orange (MO). Nearly 99% of the RhB dye was found to be degraded in 60 min while for MO, the degradation was 97% in 50 min. The pseudo-first-order rate constant was calculated as 0.072 min^?1 for the degradation of RhB and 0.075 min^?1 for the degradation of MO. The hollow shells were found to exhibit significant bacterial inhibiting efficacy at a low concentration of the particles. Comparative studies were carried out for photodegradation of Rhodamine B dye and antibacterial activity using spherical particles of ZnO and assembly of particles to form rods of ZnO. The results indicated that these hollow nanostructures could be used as a potential catalyst for the removal of dyes from water and as an antibacterial agent.     

Effect of Pressure on Plasma-Assisted Chemical Vapor. Deposition of Silicon Oxide(s)

In most chemical vapor deposition processes, the film growth rate increases with the concentrations of the reactant gases. However, in the plasma-assisted chemical vapor deposition of silicon oxide films, the deposition rate decreases when the concentrations of silane and nitrous oxide are increased by enhancing the reactor pressure from 0.5 to 2 torr (66 to 270 Pa). The deposition rate and the plasma properties have been examined for various reactor pressures to seek an improved understanding of the deposition process. Photo emissions from the plasma were monitored to determine the species present in the plasma and to calculate electron energy and density. With the increase in pressure, both the electron temperature and density decreased, and, consequently, the concentration of active species decreased. Although the concentrations of both silane and nitrous oxide increased with total pressure, the deposition rate decreased. The results emphasize the crucial importance of electron energy and density to generate sufficient concentration of active species responsible for film growth.     

Coronary heart disease: How do the benefits of ω-3 fatty acids compare with those of aspirin, alcohol/red wine, and statin drugs?

At the present time the primary cause of death of most Americans is cardiovascular disease. Approximately 20 million Americans are currently being treated with some form of statin drugs as a means to lower their blood cholesterol levels, and many of these same people also consume some combination of omega-3 FA, aspirin, and alcohol/red wine because of clinical data indicating that each of these, taken alone, seems to improve mortality. Recent studies with omega-3 FA have demonstrated a positive impact on mortality from coronary heart disease as well as from “all causes,” and this article compares their metabolic benefits with those of aspirin, alcohol/red wine, and statin drugs. The article suggests that these four compounds may have synergistic qualities and that clinical trials to study this possibility are warranted.