Studies on Indoor and Outdoor Radon/Thoron Concentration and Estimation of Radiological Parameters from Gamma Dose Rates along the Coastal Regions of Trivandrum and Kollam Districts,Kerala, India

Radiochemistry - The indoor and outdoor radon and thoron and γ-exposure rates were measured in different types of houses in selected locations along coastal regions of Trivandrum and Kollam...     

Mobile App Usage Pattern Prediction Using Hierarchical Flexi-Ensemble Clustering (HFEC) for Mobile Service Rating

Nowadays, the mobile app market becomes rapidly increased in world wide. The mobile app marketers have smart enough to understand the requirements and demands of customers and perform their aspirations. They delight them. It provides growth, profitability, and creativity with lot of inventions. The main aim of this research is to analyze the customer interest and preferences of mobile service providers. This paper proposed the clustering model named as Hierarchical Flexi-Ensemble Clustering. It provides the final result with robustness and improved quality. Before clustering, the unwanted features are removed by using the Genetic Algorithm based on the Collective Materials technique. The customer preferences are analyzes with the clustering of mobile usage patterns. The analysis determined that the app usage pattern based on the most frequent word, rating category, rating character count, rating word count and content-based rating in the google play store app dataset. Finally, the results are compared with the existing methods to analyze the superior performance of proposed method. The comparison analysis is estimated based on the based on the average hit rate at different cache sizes. The work is concluded with the app pattern prediction in the form of clustering for app marketing service. From the marketing side, they can analyze the customer preferences and satisfaction.

     

Nanoscale CuTe electrocatalyst immobilized at conductor surface for remarkable hydrogen evolution reaction

Hydrogen generation from electrocatalytic water splitting is of supreme significance for resolving energy crisis and environmental concerns. However, developing earth-abundant, efficient, and durable electrocatalyst for high-performance hydrogen evolution and complete water splitting catalysis is a rare instance. We present here the first demonstration of unique copper tellurides nano-structures (CuTe-NS) based electrocatalyst executing HER with high activity and remarkable stability. CuTe-NS based electrocatalysts grown over conductive NiF via drop-casting approach and employed for HER, while achieving a current decade and a current density of 100 mA/cm² just at 0.25 V vs. RHE and 0.27 V vs. RHE, which is comparable to the benchmark Pt/C based HER catalyst. The catalyst demonstrates well-balanced kinetic behavior, low Tafel slope of 36 mV/dec, low charge transfer resistance of 1.71 Ω, high roughness factor, and remarkable stability for more than 60 h of electrolysis. Furthermore, post-catalysis characterizations demonstrate no change in catalyst integrity, morphological, and structural attributes even after many hours of electrolysis which show sustainable behavior of catalyst for long term HER activity. Because of electrochemical and structural stabilities after long term electrolysis experiments, accessible method of preparations, and cost-effectiveness, the catalysis is highly encouraging for real-life applications.     

All‐carbon hybrids for high performance supercapacitors

A hybrid nanostructure with partially reduced graphene oxide (rGO) and carbon nanofibers (CNFs) was fabricated and used as supercapacitor electrodes. A straightforward, environmentally friendly, and low‐cost microwave‐assisted reduction process was developed for the synthesis of rGO/CNF hybrid structures. The fabricated supercapacitor devices showed a specific capacitance of 95.3 F g^?1 and a superior long‐term cycling stability. A capacitance retention of more than 97% after 11 000 galvanostatic charge discharge cycles was obtained. These and other results reported in this paper indicate that high‐rate, all‐carbon, rGO/CNF hybrid nanostructures are highly promising supercapacitor electrode materials.     

Performance Analysis of Machine Learning Classification Algorithms in Static Object Detection for Video Surveillance Applications

Video surveillance system plays a pivotal role in automatic detection of abandoned luggage/bag in public places which causes threats to the public. As, the terrorist attacks are increasing world-wide, the detection and prevention of such attack is necessary to safeguard the people in public places. In this, a novel framework for the detection and classification of static object is proposed. In the proposed work first the static objects are identified and then it is classified to check the detected object is bag or anything else. In this study, the performance of machine learning techniques like Support Vector Machine (SVM), Artificial Neural Network (ANN), K-Nearest Neighbour, and Random Forest methods are analyzed. The performance is tested in standard (PETS 2006, PETS 2007 and AVSS i-LIDS) and custom datasets. The SVM and ANN produce best results in terms of classification and accuracy. Applications of various machine learning algorithms could clearly assist for identification and prevention of terrorist attacks in public places.

     

Structural and Textural Modifications of Ternary Phosphate Glasses by Thermal Treatment

Phosphate-based glasses of composition xNa₂O−(45+(10−x))CaO−45P₂O₅ with different Na₂O, CaO (x = 1, 5, 10, 15, and 20 mol%), and invariable P₂O₅ (45 mol%) contents were prepared using the rapid melt quench technique. The obtained thermal data from differential thermal analysis revealed a decline in glass transition (T_g) and crystallization (T_c) temperatures of glasses against the compositional changes. The inclusion of Na₂O at the cost of CaO in the glass network led to a reduction in its thermal stability. The thermal treatment carried out on glasses helped to derive their glass-ceramic counterparts. The amorphous and crystalline features of samples were characterized using X-ray diffraction patterns. The crystalline species that emerged out of the calcium phosphate phases confirmed the dominance of Q¹ and Q² structural distributions in the investigated glass-ceramics. The obtained scanning electron micrographs and atomic force microscopic images confirmed the surface crystallization and textural modification of the samples after thermal treatment. The N₂-adsorption–desorption studies explored the reduction of porous structures due to thermal treatment on the melt-driven glass surface. The measured elastic moduli and Vicker's hardness values of the glasses showed an increase after thermal treatment, which were reduced against the inclusion of alkali content in both glass and glass-ceramics.     

Investigation for possible source(s) of contamination of ready-to-eat meat products with Listeria spp. and other pathogens in a meat processing plant in Trinidad

In 2003, there was a recall of three processed (chicken franks, spice ham and turkey ham ready-to-eat (RTE) meat products by a large processing plant in Trinidad as a result of contamination by Listeria monocytogenes. The study was conducted to investigate the possible source(s) of Listeria contamination of recalled RTE meat products and to determine the prevalence of Listeria spp., Salmonella spp., Escherichia coli and Campylobacter spp. in the products and air within the plant. Raw and processed meat products, as well as food contact surfaces were also tested for Salmonella spp., Listeria spp. and Campylobacter spp. initially after thorough clean-up and close-down of the plant. Faecal and effluent samples from the piggery, in close proximity to the plant, were tested for the presence of Salmonella spp., Listeria spp. and Campylobacter spp. Air samples and food contact surfaces were negative for the tested organisms. Ten (58.8%) of the 17 effluent samples and 4 (11.8%) of the 34 faecal samples were positive for Campylobacter coli. Of the 11 raw meat products tested, 10 (90.9%) were positive for E. coli and Listeria spp. either singly or in combination. Of the 32 processed RTE products tested, 11 (34.4%) were positive for E. coli, Salmonella spp., Listeria spp. and Campylobacter spp. in combination or singly. Eleven (61.1%) of 18 processed products contained unacceptable levels of aerobic bacteria using international standards. Four months later, following the implementation of recommended cleaning, sanitizing and hygienic practices at the plant, pre- and post-processed products were sampled and Listeria spp. were identified in 4 (80.0%) of the 5 raw products and in 1 of the 5 (20.0%) finished products. Two (40.0%) of the finished products contained unacceptable microbial levels. It was concluded that the close proximity of the piggery to the processing plant was not the probable source of Listeria contamination of the recalled meat products. The data suggested that improved sanitary practices on food contact surfaces and during handling of products, reduced the risk of Listeria spp. and other pathogens studied. The problem at the plant can therefore, be inferred to be due to lapses in good sanitary practices, inadequate heat treatments or the presence of pathogens particularly Listeria in biofilms on different surfaces continuously or occasionally contaminating finished products.     

Preparation of an ion-exchange chromatographic support by a "grafting from" strategy based on atom transfer radical polymerization

A new "grafting from" strategy based on surface-initiated atom transfer radical polymerization (ATRP) was first used for the preparation of a polymer-based ion-exchange support for HPLC. The most important property of the proposed method is to be applicable for the synthesis of any type of ion exchanger in both the strong and the weak forms. Monodisperse, porous poly(glycidyl methacrylate-co-ethylene dimethacrylate), poly(GMA-co-EDM) particles 5.8 mum in size were synthesized by "modified seeded polymerization". Poly(dihydroxypropyl methacrylate-co-ethylene dimethacrylate), poly(DHPM-co-EDM) particles were then obtained by the acidic hydrolysis of poly(GMA-co-EDM) particles. The ATRP initiator, 3-(2-bromoisobutyramido)propyl(triethoxy)silane was covalently attached onto poly(DHPM-co-EDM) particles via the reaction between triethoxysilane and diol groups. In the next stage, the selected monomer carrying strong cation exchanger groups, 3-sulfopropyl methacrylate (SPM), was polymerized on the initiator-immobilized particles via surface-initiated ATRP. The degree of polymerization of SPM (i.e., length of polyionic ligand) on the particles was precisely controlled by adjusting ATRP conditions. Poly(SPM)-grafted poly(DHPM-co-EDM) particles obtained with different ATRP formulations were tried as chromatographic packing in the separation of proteins by ion-exchange chromatography. The proteins were successfully separated with higher column yields with respect to the previously proposed materials. The plate heights between 100 and 150 mum were achieved with the column packed with the particles carrying the shortest poly(SPM) chains. The plate height showed no significant increase with increasing flow rate in the range of 0.5-16 cm/min.