Validation of in situ wave spectrum with JONSWAP in the Indian Ocean

The moored data buoys deployed by the National Institute of Ocean Technology (NIOT) are floating platforms designed to carry a specific suit of sensors to measure wave parameters. Waves are measured by the Motion Reference Unit (MRU), which outputs roll, pitch, compass, and heave. These data are recorded at a rate of 1 Hz for 17 minutes every three hours. For this study, wave measurements were carried out at two locations (deep and shallow water) over the same period. The wave spectra were generated from the hard disk data (roll, pitch, heave, and compass) of the moored buoys. A Matrix Laboratory (MATLAB) program was developed for generating the wave spectrum using the hard disk data. The spectrum exhibits significant features for deep- and shallow-water buoys. In a single peak spectrum the dominant peaks are observed at 0.08 and 0.1 Hz and the multi-peak spectrum energy is distributed over a wide range, from 0.05 to 0.25 Hz. The buoy spectra were compared to the Joint North Sea Wave Project (JONSWAP) spectrum in deep- and shallow-water locations in the Bay of Bengal, and also the deep-water buoy spectrum was compared to the wave model (WAM) output spectrum in the Arabian Sea. The JONSWAP spectrum mostly conforms to the buoy spectrum in regard to marine wind conditions.     

Microwave dielectric and elastic properties of glass-added Ba6−3xR8+2xTi18O54 (x = 2/3)

Microwave dielectric properties of Ba_6−3xSm_8+2xTi₁₈O₅₄ (x = 2/3) [BST] ceramics with the addition of 0–3 wt.% of various glasses have been studied. It has been found that the addition of 0.5 wt.% of the glasses decreases the sintering temperature by about 150 °C. In general, addition of 0.5 wt.% of Zn, Mg and Pb-based glasses deteriorate the quality factor, whereas aluminum and barium borosilicates do not decrease it considerably. The quality factor and dielectric constant decrease with increasing amount of glass. The temperature coefficient of resonant frequency shifts towards positive or negative depending on the composition of the glass. A glass–ceramic composite with a dielectric constant 64, Q × f nearly 8500 GHz and near to zero τ_f could be obtained at a sintering temperature of 1175 °C when 3–4 wt.% Al₂O₃–B₂O₃–SiO₂ glass was added to BST ceramic. The Young's modulus decreases with increasing amount of glass, irrespective of the composition of glass.     

AgNPs doped TEOS sol–gel coatings to prevent the adhesion of marine fouling organisms

Biosynthesis of silver nanoparticles (AgNPs) using plants is considered to be cost effective and more eco‐friendly than conventional techniques. In the authors’ previous study, they reported the biosynthesis of AgNPs using fruit extract of Aegle marmelos which were of spherical shape and high crystallinity. In order to achieve enhanced synthesis, optimisation of process parameters influencing the yield of AgNPs has been carried out in this study. Box–Behnken design has been employed to optimise the parameters in order to enhance the synthesis of AgNPs. The antimicrofouling activity of the optimised AgNPs was determined by preparing AgNPs doped TEOS sol–gels (SNSGs) and evaluating their antibiofilm activity. In addition to this, antimacrofouling activity of the AgNPs was studied against molluscs viz. Patella sp. and Trochus sp. as model organisms. Anticrustacean assay was also performed with the larvae of brine shrimp (Artemia salina) as a model crustacean fouling organism. The results indicated that the AgNPs could completely inhibit the attachment of molluscs and significantly increased the percentage of mortality against crustacean fouling larvae. Thus, this study gives scope for the possible development of formulations containing AgNPs as effective antifouling agents that could prevent the adhesion of micro and macrofoulers thereby preventing marine biofouling.Inspec keywords: silver, nanoparticles, adhesion, nanobiotechnology, microorganisms, nanofabrication, sol‐gel processing, liquid phase deposited coatings, thin films, organic compoundsOther keywords: biosynthesis, silver nanoparticle doped TEOS sol‐gel coatings, adhesion, marine fouling organisms, Box‐Behnken design, process parameter optimisation, antimicrofouling activity, antibiofilm activity, antimacrofouling activity, molluscs, Patella sp, Trochus sp, model organisms, anticrustacean assay, brine shrimp larvae, Artemia salina, model crustacean fouling organism, crustacean fouling larvae, antifouling agents, Ag     

Resource prediction and management in active networks

Active networks provide a programmable user–network interface that supports dynamic modification of the network's behavior. Network nodes, in addition to forwarding packets, perform customized computation on the messages flowing through them. Resources in an active network mainly consist of CPU and bandwidth. The inherent unpredictability of processing times of active packet poses a significant challenge in CPU scheduling. It has been identified that prior estimation of the resource requirements of a packet is very difficult since it is platform dependent and also depends on processing load at the time of execution, operating system scheduling, etc. An efficient allocation is required for the optimal utilization of resources. In this paper, resources are estimated using prediction techniques such as single exponential smoothing (SES), adaptive‐response‐rate single exponential smoothing (ARRSES) and Holt's two‐parameter estimation models. The estimated results agreed most with the actual requirements. The estimation models were compared with model criteria. An algorithm was also designed for the allocation of resources. Effectiveness of the algorithm was measured through simulation and achieved almost perfect fairness for all flows and also provided much superior delay guarantees under a highly dynamic environment. Copyright © 2008 John Wiley & Sons, Ltd.     

Fabrication of silver nanocomposite films impregnated with curcumin for superior antibacterial applications

Silver nanocomposite films are found to be very effective material for anti-bacterial application. In the present work, sodium carboxylmethyl cellulose silver nanocomposite films (SCMC SNCF) were tried for antibacterial applications. To enhance their applicability novel film-silver nanoparticle-curcumin composites have been developed. SCMC SNCF are developed from sodium carboxylmethyl cellulose (SCMC), N,N ¹ -methylenebisacrylamide (MBA) and silver nitrate solution. These films were characterized by FTIR, UV–visible, XRD, TGA, DSC and TEM techniques. The formed silver nanoparticles have an average particle size of ~15 nm as observed by transmission electron microscopy (TEM). Curcumin loading into SCMC SNCF is achieved by diffusion mechanism. The UV–Visible analysis indicated that higher encapsulation of curcumin in the films with higher SCMC content. Further, it was observed that the presence of silver nanoparticles in the films enhanced the encapsulation of curcumin indicating an interaction between them. Moreover, the antibacterial activity showed that the SCMC films generated with silver nanoparticles have a synergistic effect in the antimicrobial activity against Escherichia coli (E. coli). In order improve the healing efficacy as antibacterial agents, curcumin loaded with SCMC SNCFs were developed which showed significant inhibition of E. coli growth than the silver nanoparticles and curcumin alone film. Therefore, the present study clearly provides novel antimicrobial films which are potentially useful in preventing/treating infections.     

MHD Boundary Layer Flow of a Nanofluid Over an Exponentially Stretching Sheet in the Presence of Radiation

Effects of thermal radiation on the steady laminar magnetohydrodynamic boundary layer flow of a nanofluid over an exponentially stretching sheet is studied theoretically. The governing boundary layer equations of the problem are formulated and transformed into ordinary differential equations, using a similarity transformation. The resulting ordinary differential equations are solved numerically by the shooting method. The effects of the parameters, namely, the magnetic parameter M, radiation parameter N_R, and the solid volume fraction parameter ?, are discussed and presented in detail. Different types of nanoparticles namely, Cu, Ag, Al₂O₃, and TiO₂ with the base fluid water, are studied. It is found that the nanoparticles with low thermal conductivity, TiO₂ have better enhancement on heat transfer, compared to Cu, Ag, and Al₂O₃. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res, 43(4): 321–331, 2014; Published online 3 October 2013 in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21077     

Modeling of Source Pocket Engineered PNPN Tunnel FET on High-K Buried Oxide (H-BOX) Substrate for Improved ON Current

Silicon - In this paper, an analytical model has been developed for a single gate tunnel FET, introduced with a highly doped pocket in the vicinity of the source-channel junction and the bottom...     

Simultaneous wireless information and power transmission-based power transfer and energy prediction for efficient communication with golden Taylor sea lion optimization in wireless sensor network

Wireless Sensor Network (WSN) is an emerging lower cost and resourceful solution, which enables controlled observation of the environment. The high amount of energy is required in wireless networks during the transmission of data. Here, Golden Ant Lion Whale Optimization (GALWO) and Golden Taylor Sea Lion Optimization (GTSLnO) techniques are presented for cluster head (CH) selection and prediction of neighbor nodes' age. The six stages performed in this work are setup, steady-state, prediction, power transfer, communication or route discovery, and route maintenance stages. In the setup level, CH selection is carried out by GALWO, which is the combination of Ant Lion Whale Optimization (ALWO) with Golden Search Optimization (GSO). Moreover, ALWO is an integration of Ant Lion Optimizer (ALO) with the Whale Optimization Algorithm (WOA). In the steady state, the distance, energy, delay, throughput, and trust update are considered as objective functions. In the prediction stage, the Deep Convolutional Neural Network (Deep CNN) is utilized for age prediction of neighbor nodes, wherein Deep CNN is tuned by employing GTSLnO. The GTSLnO is an incorporation of GSO and Taylor series with Sea Lion Optimization (SLnO). Then, the power transfer stage is done utilizing simultaneous wireless information and power transmission (SWIPT). Thereafter, the communication/route discovery stage is conducted for path selection through neighbor node, and lastly, the route maintenance stage is carried out. The GTSLnO–Deep CNN achieved a minimal delay of 0.089 s, maximal residual energy, throughput, and trust of 0.500 J, 98,843 kbps, and 0.452 for DoS attack.     

Electrostatic characteristics of a high-k stacked gate-all-around heterojunction tunnel field-effect transistor using the superposition principle

Journal of Computational Electronics - We use the superposition method to model the electrostatic characteristics of a high-k stacked gate-all-around heterojunction tunneling field-effect...     

TFET Biosensor Simulation and Analysis for Various Biomolecules

Silicon - This paper investigates the simulation and performance of Tunnel field effect transistor (TFET) with a nanocavity in it, which can be used for bio sensing application. The entire...