Stabilization of melon phase during the formation of g-C3N4 from melamine and its structure-property relationship towards photocatalytic degradation of dyes under sunlight

Journal of Materials Science: Materials in Electronics - The structure-property relationship of various intermediates formed during the step-wise dwell-in thermal condensation of melamine to g-C3N4...     

Opposition-based equilibrium optimizer algorithm for identification of equivalent circuit parameters of various photovoltaic models

Journal of Computational Electronics - The simulation, assessment, and harvesting of maximum energy of the solar photovoltaic (PV) system require accurate and fast parameter estimation for solar...     

Secure and reliable routing in cognitive radio networks

Due to the mobility of node and different spectrum availability pattern, CR networks are frequently divided into unpredictable partitions. Usually, these partitions are irregularly connected; hence, secure and reliable routing becomes major issue for these types of network. In order to overcome these issues, we propose a secure and reliable routing in CRN based on distributed Boltzmann–Gibbs learning algorithm. This algorithm is implemented for relay node selection phase. In addition, the authentication is done based on secure routing distributed Boltzmann–Gibbs learning algorithm. We consider the metrics such as trust value and total delay for the successful and reliable transmission of the packet. Also, in order to increase the reliability, we implement LDPC code at the time of relay node selection phase. The proposed code helps to cancel any kind of electronic interference and channel noise interference.     

Experimental characterization of woven jute‐fabric‐reinforced isothalic polyester composites

In this article, mechanical performance of isothalic polyester‐based untreated woven jute‐fabric composites subjected to various types of loading has been experimentally investigated. The laminates were prepared by hand lay‐up technique in a mold. Specimens for tests were fabricated as per ASTM standards. All the tests (except impact) were conducted on closed loop servo hydraulic MTS 810 material test system using data acquisition software Test Works‐II. From the results obtained, it was found that the tensile strength and tensile modulus of jute‐fabric composite are 83.96% and 118.97% greater than the tensile strength and modulus of unreinforced resin, respectively. The results of other properties, such as flexural, in‐plane shear, interlaminar shear, impact, etc., also revealed that the isothalic‐polyester‐based jute‐fabric composite have good mechanical properties and can be a potential material for use in medium load‐bearing applications. The failure mechanism and fiber‐matrix adhesion were analyzed by scanning electron microscope. Effects of long‐term immersion in water on mechanical properties are also presented. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2650–2662, 2007     

Static contact stress analysis of a spur gear tooth using the finite element method, including frictional effects

The literature available on gear tooth contact stress problems is not very extensive and that available does not explain the method by which analysis was carried out. In this paper an attempt has been made to study the contact stresses of a pair of mating gear teeth, under static conditions, by using a two-dimensional finite element method and the Lagrangian multiplier technique. The contact condition at the neighbouring node pair, namely, the contact existing over a number of node pairs in the contact zone, has been considered. To study the effect of friction between the mating gear teeth a range of average static friction coefficients, from 0.0 to 0.3, has been considered. The actual length of contact against the calculated length of contact is discussed. The variation of contact stress along the contact surface in a direction normal to the mating surfaces, which will give an idea about the depth of hardening required, is also presented.     

Lagenaria siceraria – synthesised ZnO NPs – a valuable green route to control the malaria vector Anopheles stephensi

Malaria is a dangerous disease affecting humans and animals in tropical and subtropical areas worldwide. According to recent estimates, 3.2 billion people are at risk of malaria. Many drugs are in practices to control this disease and their vectors. Eco‐friendly control tools are needed to fight vectors of this important disease. Nanotechnology is playing a key role in the fight against many public health emergencies. In the present study, Lagenaria siceraria aqueous peel extract was used to prepare zinc oxide nanoparticles (ZnO NPs), then tested on Anopheles stephensi eggs, larvae and pupae. The L. siceraria ‐synthesised ZnO NPs were characterized additionally by FTIR, AFM, XRD, UV‐Vis spectroscopy, EDX, and SEM spectroscopy The ovicidal, larvicidal, pupicidal and repellent activities of L. siceraria and green‐synthesised ZnO NPs were analysed on A. stephensi. The potential mechanism of action of ZnO NPs was studied investigating the changes in various enzyme activities in A. stephensi IV instar larvae. Furthermore, the smoke toxicity of L. siceraria ‐based cones against A. stephensi evoked higher mortality if compared with the control. Overall, the present study concluded that L. siceraria peel extract and its mediated green synthesised ZnO NPs represent a valuable green option to manage against malaria vectors.Inspec keywords: X‐ray diffraction, Fourier transform spectra, nanomedicine, silver, enzymes, zinc compounds, nanotechnology, nanoparticles, diseases, pest control, transmission electron microscopy, pharmaceutical technology, health hazardsOther keywords: ZnO, nanotechnology, drugs, diseases, siceraria peel, scanning electron microscope spectroscopy, Fourier‐transform infrared spectroscopy, anopheles stephensi, malaria vector, lagenaria siceraria     

A static analysis of metal matrix composite spur gear by three-dimensional finite element method

A number of engineering components have recently been made using metal matrix composite (MMC) materials, due to their overwhelming advantages, such as light weight high strength, higher dimensional stability and minimal attack by environment, when compared with polymer-based composite materials, even though the cost of MMCs are very high. Power transmission gears are one such area able to make use of MMC materials. Here an attempt is made to study and compare the performance of gears made of MMC materials with that of conventional steel material gears. It may be concluded from this study that MMC materials are highly suitable for making gears that are to transmit even fairly large power.     

Characterization Studies of Mullite Coatings on Cast Aluminum

Thermal barrier coating of mullite was plasma sprayed on cast aluminum A 356.0, in the T6 condition (solution treated, quenched and artificially aged) for use in internal combustion engine applications. This study pertains to the mechanical, thermal, wear, corrosion and micro structural characterization of the coating. An average coating tensile strength of 50 MPa and average adhesive bond strength of 20 MPa was measured in the mechanical tests. A wear factor of 0.7 × 10⁻³ mg/Nm was measured in the wear studies using a pin on disk apparatus. An average value of 0.151 W/m K was measured in the thermal conductivity test. The coating withstood 100 cycles in the thermal shock test, without any sign of spallation. Corrosion tests showed no signs of corrosion even after 500 h. The microstructural and porosity studies were conducted using an optical microscope and scanning electron microscope with an energy dispersive spectroscopy (EDS) attachment. The studies revealed a crystalline microstructure of the substrate, which correspond to the splat structure of the coating. The porosity of the coated layers ranged from 6 to 21% by volume, at an average of 12-16%. EDS studies showed the elements present in the coating. X-ray diffraction patterns taken on coated specimens, showed the phases present in the coating, and indicated a crystalline structure of the coating along with some amorphous matter.     

Static stress analysis of a composite bevel gear using a three-dimensional finite element method

The possibility of using composite materials for power transmission spur gear, from a static strength point of view, have been proved by the authors in their previous study. In this present work an attempt has been made to study the behaviour of composite bevel gear from a static load point of view using a three-dimensional finite element method. The performance of two composite material bevel gears are presented and compared with a carbon steel gear. From a static strength point of view a glass epoxy bevel gear is slightly closer to a carbon steel bevel gear than a boron/epoxy bevel gear; but from a displacement point of view glass/epoxy deviates from that of carbon steel much more than boron/epoxy, unlike the case of a composite spur gear, where boron/epoxy was better both from strength and displacement points of view. Hence from the results it is concluded that composite materials such as boron/epoxy can be very much thought of as a material for power transmission bevel gears.