Hilbert resonator-based multiband tunable graphene metasurface polarizer for lower THz frequency

Journal of Computational Electronics - In this article, we propose different Hilbert shape-based tunable and multiband polarizers for the lower-terahertz frequency range. The tunability of this...     

Performance Evaluation of Multilayer Clustering Network Using Distributed Energy Efficient Clustering with Enhanced Threshold Protocol

Wireless Personal Communications - In this research, pure deterministic system has been established by a new Distributed Energy Efficient Clustering Protocol with Enhanced Threshold (DEECET) by...     

Microstructure and Property Characterization of Sintered Si3N4, SiC, and SiAlON

Commercially produced pressureless sintered Si₃N₄, SiC, and SiAlON were characterized with respect to density, phases present, bend strength, and oxidation resistance. The room-temperature bend strengths of sintered Si₃N₄, SiC, and SiAlON are comparable. However, the room-temperature strengths are much lower (=40 to 50%) than the room-temperature strength of hot–pressed Si₃N₄ (NC-132). The strength loss in Si₃N₄ and SiAlON materials at high temperature was attributed to a viscous grain-boundary phase retained during cooling from the sintering temperature. The oxidation resistance of sintered a-SiC was the best of any materials tested.     

An energy optimization in wireless sensor networks by using genetic algorithm

Wireless sensor networks (WSNs) are used for several commercial and military applications, by collecting, processing and distributing a wide range of data. Maximizing the battery life of WSNs is crucial in improving the performance of WSN. In the present study, different variations of genetic algorithm (GA) method have been implemented independently on energy models for data communication of WSNs with the objective to find out the optimal energy \(\hbox {(E)}\) consumption conditions. Each of the GA methods results in an optimal set of parameters for minimum energy consumption in WSN related to the type of selected energy model for data communication, while the best performance of the GA method [energy consumption \((\hbox {E}=3.49\times 10^{-4}\,\hbox {J})\)] is obtained in WSN for communication distance (d) \({\ge }87\,\hbox {m}\) in between the sensor cluster head and a base station.     

A cellular Trojan Horse for delivery of therapeutic nanoparticles into tumors

Destruction of hypoxic regions within tumors, virtually inaccessible to cancer therapies, may well prevent malignant progression. The tumor's recruitment of monocytes into these regions may be exploited for nanoparticle-based delivery. Monocytes containing therapeutic nanoparticles could serve as "Trojan Horses" for nanoparticle transport into these tumor regions. Here we report the demonstration of several key steps toward this therapeutic strategy: phagocytosis of Au nanoshells, and photoinduced cell death of monocytes/macrophages as isolates and within tumor spheroids.     

Low cycle fatigue behaviour of Inconel® alloy 783

Low cycle fatigue (LCF) tests were performed on Inconel® Alloy 783 at a strain rate of 3×10^?3s^?1 and a strain amplitude of ±0.6%. The tests were conducted in the temperature range, 573 to 923 K besides room temperature. Further, influence of strain amplitude on LCF behaviour was studied at a constant temperature of 923 K using strain amplitudes in the range, ±0.3 to ±0.8%. Creep-fatigue interaction tests were conducted at a strain amplitude of ±0.4%, at 923 K. The material generally showed a stable stress response followed by a region of continuous softening upto failure. Also, the alloy was seen to exhibit dynamic strain ageing (DSA) in the temperature range, 573 to 723 K as evidenced by the observed peaks in the half-life stress in the above temperature range. Dynamic strain ageing was seen to offset the softening exhibited by the alloy outside the above temperature range. Fractography/EDS analysis of the failed samples showed numerous brittle Nb-rich precipitates that were seen to influence crack propagation. A continuous reduction in the LCF life was noticed with increase in the test temperature. The observed material behaviour has been correlated with the damage mechanisms through microstructural observations.     

Synthesis of CuO samples by co-precipitation and green mediated combustion routes: Comparison of their structural,optical properties,photocatalytic, antibacterial,haemolytic and cytotoxic activities

The goal of this research is to prepare novel, inexpensive, environment friendly and efficient crystalline CuO samples by green mediated combustion and co-precipitation routes towards environmental remediation and biomedical applications. The influence of preparation routes and Aloe barbadensis miller (Aloe vera) gel on the morphology, size, crystallinity, band gap, defects, photocatalytic, antibacterial, haemolytic and anticancer behaviour of CuO samples were explored. The PXRD, XPS, SEM, TEM, HRTEM and FT-IR were performed to confirm the formation of CuO samples. FTIR studies showed all possible bands of Aloe barbadensis miller gel. FTIR displaying the occurrence of new peaks and peak shifts in the CuO synthesized by green mediated combustion route compared to co-precipitation route is an evidence of the effective interactions between CuO and Aloe vera gel. The PL and UV–Vis-DRS techniques measured the optical sensitivity and tuning of band gap of the CuO samples. The crystallinity and surface properties dependent photocatalytic activities for decolourization of MB and RhB under both UV and Sunlight irradiation were investigated. The results indicated that green mediated synthesized CuO sample displayed high photocatalytic activity compared with co-precipitation route synthesized CuO sample, which mainly resulted from the low crystallinity and crystallite size (6 nm), narrow band gap (1.73 eV) and lower recombination of charge carriers. These synthesized CuO samples also demonstrate excellent antibacterial activity against the bacteria Gram-positive (S. aureus) and Gram-negative (E. coli). The present study probes into the cytotoxicity of CuO samples employing root cells of Allium cepa. In addition, we report the haemolytic activity on goat and human blood along with the implementation of green synthesized CuO sample using an Aloe barbadensis miller extract for the evaluation of anticancer activity in human cervical cancer (HeLa) cells with IC50 value of 310.1 μg/ml. Our studies focus on developing biosynthesized nanomaterials for environmental remediation and biomedical applications.     

Impedance spectra analysis to characterize interdigitated electrodes as electrochemical sensors

Interdigitated electrode (IDE) arrays have been used widely for electrochemical impedance spectroscopy (EIS). Here, we present an in-depth analysis of interdigitated electrode impedance spectra. Such an analysis is necessary for the identification of the contribution of each interdigitated electrode circuit element to the impedance change. We also discuss the importance of the solution conductivity in impedance spectroscopy showing that the use of low conductivity solutions is advantageous when inter-digit solution resistance and geometric capacitance need to be monitored.     

Effectiveness of radiation processing in elimination of Salmonella typhimurium and Listeria monocytogenes from sprouts

The effectiveness of radiation treatment in eliminating Salmonella Typhimurium and Listeria monocytogenes on laboratory inoculated ready-to-eat sprouts was studied. Decimal reduction doses (D10-values) for Salmonella Typhimurium and L. monocytogenes in dry seeds of mung (green gram), matki (dew gram), chana (chick pea), and vatana (garden pea) ranged from 0.189 to 0.303 kGy and 0.294 to 0.344 kGy, respectively. In sprouts made from these seeds, the D10-values ranged from 0.192 to 0.208 kGy for Salmonella Typhimurium and from 0.526 to 0.588 kGy for L. monocytogenes. Radiation treatment with a 2-kGy dose resulted in complete elimination of 10(4) CFU/g of Salmonella Typhimurium and 10(3) CFU/g of L. monocytogenes from all the four varieties of sprouts. No recovery of Salmonella Typhimurium and L. monocytogenes was observed in the radiation treated samples stored at 4 and 8 degrees C up to 12 days. Radiation treatment with 1 kGy and 2 kGy resulted in a reduction of aerobic plate counts and coliform counts by 2 and 4 log CFU/g, respectively; the yeast and mold counts and staphylococci counts decreased by 1 and 2 log CFU/g, respectively. However, during postirradiation storage at 4 and 8 degrees C, aerobic plate counts, coliform counts, yeast and mold counts, and staphylococci counts remained constant throughout the incubation period. This study demonstrates that a 2-kGy dose of irradiation could be an effective method of processing to ensure microbial safety of sprouts.     

Production of Cellulases through Solid State Fermentation Using Kinnow Pulp as a Major Substrate

A study was conducted to appraise the potential of using kinnow pulp for production of cellulases by Trichoderma reesei Rut C-30. Out of the different combinations tried out, dried kinnow pulp supplemented with wheat bran in the ratio of 4:1 resulted in the highest filter paper cellulase (FPase) activity of 13.4 IU/gds whereas endo-1,4-β-glucanase (CMCase) activity was found to be best when kinnow pulp was supplemented with wheat bran in the ratio 3:2 using Mandel Weber (MW) medium. β-glucosidase activity of 18 IU/gds was again found to be maximum in treatment involving 3:2 ratio of kinnow pulp to wheat bran in MW medium. However, supplementing kinnow pulp with wheat bran in 3:2 using water as medium resulted in an FPase:β-glucosidase ratio of nearly 1:1 which is considered to be most appropriate for achieving ideal saccharification efficiency in case of pretreated lignocellulosic material. Thus, this study involved the utilisation of kinnow pulp for production of cellulases and demonstrated that a substrate which does not find any commercial significance and causes environmental pollution due to its poor disposal holds promise as a substrate for production of cellulases.