Annealing properties of a pre-irradiation annealed plastic track detector

The studies regarding the annealing properties of a pre-irradiation annealed Makrofol N track detector showed that under “moderate annealing conditions”, the maximum etched track length l_max, can be increased. The increase becomes maximum at pre- and post-irradiation annealing temperatures of 80°C and 60°C respectively.     

Measurement of gamma radiation from rocks used as building material in Tiruchirappalli district,Tamil Nadu,India

Tiruchirappalli district is naturally endowed with rich building material resources which are also used in neighboring districts. Hence, measurements of activity concentrations and absorbed dose rate of primordial radionuclides (²³⁸U, ²³²Th and ⁴⁰K) in the rock samples collected from 14 sedimentary rocks and 9 igneous rocks were carried out employing gamma ray spectrometry. In sedimentary rocks the geometric mean activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K were found to be 7.4, 29.5 and 233.6 Bq kg^?1, respectively. On the other hand in igneous rocks geometric mean activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K were distinctly higher and found to be 13.1, 105.7 and 888.8 Bq kg^?1, respectively. The mean radium equivalent activity (Ra_eq) recorded in both sedimentary (20.8 Bq kg^?1) and igneous rocks (245.4 Bq kg^?1) were well within the limit prescribed for dwellings (370 Bq kg^?1) except Vilathupatti (689.3 Bq kg^?1) and Narthamalai (371.6 Bq kg^?1). The mean absorbed dose rate from igneous rock (115 nGy h^?1) exceeded the prescribed limit of 55 nGy h^?1. The mean indoor annual effective dose from the sedimentary rock (0.056 mSv y^?1) and igneous rock (0.580 mSv y^?1) did not exceed the prescribed limit (1 mSv y^?1) except the igneous rock from Vilathupatti (1.51 mSv y^?1). The study concludes that sedimentary and igneous rocks analyzed were radiologically safe when used as building materials except igneous rock from Vilathupatti and Narthamalai.     

The environmental applications of activated carbon/zeolite composite materials

Over the past couple of years, the resurgence of placing an effective and sustainable amendment to combat against the auxiliary industrial entities, remains a highly contested agenda from a global point. With the renaissance of activated carbon, there has been a steadily growing interest in the research field. Recently, the adoption of zeolite composite, a prestigious advanced catalyst which formulates the enhancement of adsorption rate and hydrogen storage capability, has fore fronted to be a new growing branch in the scientific community. Confirming the assertion, this paper presents a state of art review of activated carbon/zeolite composite technology, its fundamental background studies, and environmental implications. Moreover, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbon/zeolite composite represents a potentially viable and powerful tool, leading to the plausible improvement of environmental preservation.     

Surface phases and photocatalytic activity correlation of Bi2O3/Bi2O4-x nanocomposite

UV-visible irradiation induces surface alteration of Bi2O3 leading to Bi2O3/Bi2O4-x nanocomposites with excellent photocatalytic activity.     

A second generation formal synthesis of (-)-cephalotaxine

A second generation formal synthesis of the alkaloid (-)-cephalotaxine has been achieved using an alkylidene carbene 1,5-CH insertion reaction to establish a key quaternary stereocenter. The carbene precursor was readily derived from L-proline, and the 1,5-CH insertion reaction was performed under Ohira's conditions using lithiotrimethylsilyldiazomethane (LTDM), which gave the desired spirocyclic product in 74% yield. The hydroxymethyl group was then oxidized and then decarbonylated (93%), and this material was easily transformed into the desired Friedel-Crafts cyclization precursor. Exposure of this material to SnCl4 then gave the desired pentacyclic product, which was identical to that previously prepared by Mori and thus represents a formal total synthesis of (-)-cephalotaxine.     

Direct Electrochemical Sensing of Phenazine‐1‐carboxylic Acid Secreted by Pseudomonas chlororaphis subsp. aureofaciens BCRC 11057T Using Disposable Screen‐printed Carbon Electrode

A novel electrochemical approach for direct recognition of antibiotic phenazine‐1‐carboxylic acid (PCA) was developed. PCA was electropolymerized on preanodized screen‐printed carbon electrode (SPCE*‐PCA) through repetitive cyclic voltammetry and characterized by XPS and FESEM. Electron transfer involved intermediate phenomenon of diffusion‐controlled redox process and surface bound redox reaction. At pH 8 (optimum), SPCE*‐PCA had a detection limit of 0.51±0.04 μM, a quantification limit of 1.7±0.13 μM, linearity of up to 50 µM, a repeatability of 15.5 % and a reproducibility of 1.7 %. PCA secreted by Pseudomonas chlororaphis subsp. aureofaciens BCRC 11057^T was investigated successfully using present single run approach.     

Influence of Metal Oxides on Platinum Activity towards Methanol Oxidation in H2SO4 solution

Pt–CeO₂/C, Pt–TiO₂/C, and Pt–ZrO₂/C electrocatalysts were prepared by using a modified microwave‐assisted polyol process. Physical characterization was performed by using XRD, TEM, and EDX analyses. The incorporation of different metal oxides increased the dispersion degree of Pt nanoparticles and reduced their diameter to 2.50 and 2.33 nm when TiO₂ and ZrO₂ were introduced to Pt/C, respectively. The electrocatalytic activity of various electrocatalysts was examined towards methanol oxidation in H₂SO₄ solution by using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Among the studied composites, Pt–ZrO₂/C was selected to be a candidate electrocatalyst for better electrochemical performance in direct methanol fuel cells.     

Eco-friendly micellar HPTLC technique for the simultaneous analysis of co-formulated antibiotic cefoperazone and sulbactam in pure form and vial pharmaceutical formulation

JPC – Journal of Planar Chromatography – Modern TLC - A rapid, sensitive, and eco-friendly micellar high-performance thin-layer chromatography (HPTLC) technique for the simultaneous...     

Families of univariate and bivariate subdivision schemes originated from quartic B-spline

Families of parameter dependent univariate and bivariate subdivision schemes are presented in this paper. These families are new variants of the Lane-Riesenfeld algorithm. So the subdivision algorithms consist of both refining and smoothing steps. In refining step, we use the quartic B-spline based subdivision schemes. In smoothing step, we average the adjacent points. The bivariate schemes are the non-tensor product version of our univariate schemes. Moreover, for odd and even number of smoothing steps, we get the primal and dual schemes respectively. Higher regularity of the schemes can be achieved by increasing the number of smoothing steps. These schemes can be nicely generalized to contain local shape parameters that allow the user to adjust locally the shape of the limit curve/surface.