Effect of Cathode Designs on Radiation Emission of Compact Diode (CD) Device

A comparative study on the radiation emission such as X-ray yield and efficiency has been carried out in compact diode device. Two different designs of cathode having sharp-edged razor blade (of 0.5 mm thickness with width 2 mm) and a sewing machine needle (of 0.5 mm diameter at tip with length of 39 mm) have been tested for this study. The radiation emission (X-ray yield) was determined by employing two set of PIN diodes at fixed positions. The maximum X-ray yield depends on cathode designs and electrodes separation in few mm. The yield of X-ray is small in the case of sharp-edged razor blade cathode than the sewing machine needle cathode. The X-ray yield, measured by 4π-geometry, shows its dependence on the cathode designs. The maximum X-ray yield is found to be 939.2 ± 65.7 mJ with efficiency of 0.4142 ± 0.0289%. This study indicates that the compact diode device could be optimized to a great extent for optimal X-ray yield by using an appropriate cathode design.     

Perspectives of Polystyrene Composite with Fullerene,Carbon Black,Graphene, and Carbon Nanotube: A Review

The use of polystyrene-based materials has become very important due to a wide range of industrial applications. Different types of nanofillers such as fullerene, carbon black, graphite, graphene, and carbon nanotube have been used with polystyrene to attain high-performance materials. Fabrication and unique properties of composites are considered here. Use of fullerene to improve thermal stability of polystyrene/fullerene composite has been explored. Polystyrene /carbon black composite have found to improve thermal, electrical, and rheological properties. Polystyrene/graphite nanosheet composite have been used in different applications due to mechanical and electrical properties. Polystyrene/carbon nanotube composite have been studied for enhanced tribological properties.     

Thermally and mechanically superior hybrid epoxy–silica polymer films via sol–gel method

Hybrid organic–inorganic polymer films composed of an epoxy resin crosslinked with a flexible diamine hardener, and a silica reinforcing phase were produced and their thermo-mechanical properties were determined. Two types of hybrid epoxy–silica polymer films, named EAS-1 and EAS-2, were obtained by hydrolysis and condensation of various amounts of tetraethoxysilane within epoxy network matrix. In EAS-2 hybrids, minor amounts of an amine silane coupling agent were added to enhance interfacial compatibility. FTIR spectroscopy confirmed the formation of organic and inorganic networks. The grafting of amine silane on to the epoxy resin influenced the size and distribution of hyper-branched clusters of silica as indicated by transmission electron microscopy (TEM). The dynamic mechanical and thermal analysis (DMTA) and thermo-gravimetric analysis (TGA) results showed an increase in the storage modulus, the glass-transition temperature, and the thermal stability of hybrid polymer films as compared to the neat matrix. The integration of amine silane coupling agent produced smaller, effectively dispersed silica nanoparticles and consequently improved the ultimate properties of polymer films.     

A systematic review of search-based testing for non-functional system properties

Search-based software testing is the application of metaheuristic search techniques to generate software tests. The test adequacy criterion is transformed into a fitness function and a set of solutions in the search space are evaluated with respect to the fitness function using a metaheuristic search technique. The application of metaheuristic search techniques for testing is promising due to the fact that exhaustive testing is infeasible considering the size and complexity of software under test. Search-based software testing has been applied across the spectrum of test case design methods; this includes white-box (structural), black-box (functional) and grey-box (combination of structural and functional) testing. In addition, metaheuristic search techniques have also been applied to test non-functional properties. The overall objective of undertaking this systematic review is to examine existing work into non-functional search-based software testing (NFSBST). We are interested in types of non-functional testing targeted using metaheuristic search techniques, different fitness functions used in different types of search-based non-functional testing and challenges in the application of these techniques. The systematic review is based on a comprehensive set of 35 articles obtained after a multi-stage selection process and have been published in the time span 1996–2007. The results of the review show that metaheuristic search techniques have been applied for non-functional testing of execution time, quality of service, security, usability and safety. A variety of metaheuristic search techniques are found to be applicable for non-functional testing including simulated annealing, tabu search, genetic algorithms, ant colony methods, grammatical evolution, genetic programming (and its variants including linear genetic programming) and swarm intelligence methods. The review reports on different fitness functions used to guide the search for each of the categories of execution time, safety, usability, quality of service and security; along with a discussion of possible challenges in the application of metaheuristic search techniques.     

Chiral Polyamino Alcohols via Hydroaminomethylation: A New Class of Polyamines for Dendritic Cores and Ligand Precursors

In this contribution, the synthesis of a new class of chiral polyamino alcohols (PAA) via a two‐step hydroaminomethylation/hydrolysis procedure is reported. The chiral polyamines are obtained by hydroaminomethylation of N‐olefinic oxazolidinones with different amines in first step followed by hydrolysis of the resulting polyamines to give the chiral PAA in the second step. The dendritic chiral PAA (Mw=1300–1400 g mol⁻¹) are also synthesized efficiently through a multifold hydroaminomethylation/hydrolysis procedure. Furthermore, chiral PAA are investigated as ligands in ruthenium‐catalyzed asymmetric hydrogen transfer reduction of acetophenone to 1‐phenyl alcohol.     

Experimental analysis of a metal hydride hydrogen storage system with hexagonal honeycomb-based heat transfer enhancements-part B

This study is a continuation of the computational analysis of the reactor equipped with hexagonal honeycomb based heat transfer enhancements, performed in Part A of the study. In the present study, the performance of the metal alloy and the reactor is investigated experimentally. The gravimetric capacity and reaction kinetics of the alloy La_0.9Ce_0.1Ni₅ are determined. The performance of the reactor under different external environments is noted. The influence of operating conditions such as supply pressure, heat transfer fluid, heat transfer fluid temperature on the reactor performance is investigated. Evaporative cooling as a heat removal technique for metal hydride based hydrogen storage reactors is tested for the first time and compared to conventional heat removal methods. It is found to improve the heat transfer from the alloy bed significantly.     

Enhanced stability and permeation potential of nanoemulsion containing sefsol-218 oil for topical delivery of amphotericin B

Aim: To characterize the enhanced stability and permeation potential of amphotericin B nanoemulsion comprising sefsol-218 oil at varying pH and temperature of aqueous continuous phase.

Methodology: Several batches of amphotericin B loaded nanoemulsion were prepared and evaluated for their physical and chemical stability at different pH and temperature. Also, a comparative study of ex vivo drug permeation across the albino rat skin was investigated with commercial Fungisome® and drug solution at 37?°C for 24?h. The extent of drug penetrated through the rat skin was thereby evaluated using the confocal laser scanning microscopy (CLSM).

Results and conclusions: The optimized nanoemulsion demonstrated the highest flux rate 17.85?±?0.5?µg/cm²/h than drug solution (5.37?±?0.01?µg/cm²/h) and Fungisome® (7.97?±?0.01?µg/cm²/h). Ex vivo drug penetration mechanism from the developed formulations at pH 6.8 and pH 7.4 of aqueous phase pH using the CLSM revealed enhanced penetration. Ex vivo drug penetration studies of developed formulation comprising of CLSM revealed enhanced penetration in aqueous phase at pH 6.8 and 7.4. The aggregation behavior of nanoemulsion at both the pH was found to be minimum and non-nephrotoxic. The stability of amphotericin B was obtained in terms of pH, optical density, globular size, polydispersity index and zeta potential value at different temperature for 90 days. The slowest drug degradation was observed in aqueous phase at pH 7.4 with shelf life 20.03-folds higher when stored at 4?°C (3.8 years) and 5-fold higher at 25?°C (0.951 years) than at 40?°C. The combined results suggested that nanoemulsion may hold an alternative for enhanced and sustained topical delivery system for amphotericin B.     

AdDroid: Rule-Based Machine Learning Framework for Android Malware Analysis

Mobile Networks and Applications - Recent years have witnessed huge growth in Android malware development. Colossal reliance on Android applications for day to day working and their massive...     

Control design approach for improved voltage stability in microgrid energy storage system

Microsystem Technologies - Nowadays, microgrid energy storage system is in great demand in order to compensate the demand-generation mismatch. In this study a new control design strategy is...