ESA: a hybrid bio-inspired metaheuristic optimization approach for engineering problems

In this paper, a hybrid bio-inspired metaheuristic optimization approach namely emperor penguin and salp swarm algorithm (ESA) is proposed. This algorithm imitates the huddling and swarm behaviors of emperor penguin optimizer and salp swarm algorithm, respectively. The efficiency of the proposed ESA is evaluated using scalability analysis, convergence analysis, sensitivity analysis, and ANOVA test analysis on 53 benchmark test functions including classical and IEEE CEC-2017. The effectiveness of ESA is compared with well-known metaheuristics in terms of the optimal solution. The proposed ESA is also applied on six constrained and one unconstrained engineering problems to evaluate its robustness. The results reveal that ESA offers optimal solutions as compared to the other competitor algorithms.

     

Functionalization of poly(4‐vinyl pyridine) grafted cellulose by quaternization reactions and a study on the properties of postquaternized copolymers

Graft copolymers of 4‐vinyl pyridine (4‐VP) synthesized by using simultaneous gamma irradiation method were further functionalized by post polymer quaternization reactions at N: of the pyridine ring of the graft copolymers. Using the optimum grafting conditions reported earlier for the grafting of 4‐VP onto extracted cellulose, graft copolymer was synthesized in bulk and was further functionalized by quaternization with hexyl bromide (C₆H₁₃Br), benzyl chloride (C₆H₅CH₂Cl), n‐butyl bromide (C₄H₉Br), and maleic anhydride (MAnh). The quaternized polymers were studied for treatment of hardness of water, antibacterial action, emulsification properties, metal ion uptake and stability toward thermal degradation, and enzymatic and alkaline hydrolysis to evaluate the suitability of these polymers in harsh chemical, microbial, and thermal environments. The functionalized polymers were also characterized for surface morphology (SEM), elemental analysis and FTIR for investigations of structural aspects, and to obtain evidence for quaternization. The functionalized copolymers exhibit a range of properties that can be used in many fields of water purification technologies including antibacterial agents and ion exchangers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2454–2464, 2004     

Power-law shear-thinning flow around a heated square bluff body under aiding buoyancy at low Reynolds numbers

Power-law shear-thinning fluid flow over a heated square bluff body is numerically investigated under aiding buoyancy mixed convection at low Reynolds numbers. Semi-explicit finite volume code is developed to solve the governing equations along with the appropriate boundary conditions. Both aiding buoyancy and shear-thinning natures are found to augment the heat transfer rate from the surface of the long square bar. In aiding buoyancy, the total drag coefficient is found to be more for the square cylinder than that of the circular cylinder, whereas the average cylinder Nusselt number for the square cylinder is found to be lower than the circular one on equal side/diameter basis. Maximum augmentation in heat transfer is found to be approximately 20% with respect to forced convection. Finally, a heat transfer correlation is established by using the Colburn heat transfer factor.     

Thermal and thermo-hydraulic performance investigation of double-pass packed bed solar air heaters under external recycle

In the present investigation, two types (Type A and Type B) of the double-pass packed bed solar air heater under external recycle are investigated theoretically. In Type A, the porous media is considered in the upper channel, whereas in Type B, the porous media is considered in the lower channel. Iron scraps are used as a packed bed material (porous media) to strengthen the convective heat transfer coefficient for air flowing through the packed bed. The mathematical model for these two air heaters operating under forced convection mode is presented. The results revealed that the thermal and thermo-hydraulic efficiencies of Type A are higher as compared to Type B. In order to validate the models, the theoretical results obtained from the conventional model of Type B are compared with the theoretical results obtained from the previous investigation and showed that good agreement is achieved.     

A 640-Gbps, 15.2344-b/s/Hz full-duplex optical fiber/wireless single-channel coherent communication system using IQM-based DP-256-QAM and DSP techniques

Photonic Network Communications - A full-duplex optical fiber/wireless single-channel coherent communication system is presented for high-speed data center interconnections. In-phase and quadrature...     

Effect of doping of different rare earth (europium,gadolinium, dysprosium and neodymium) metal ions on structural,optical and photocatalytic properties of LaFeO3 perovskites

Different rare earth substituted perovskites LaRE_xFe_(1-x)O_3(where RE=Eu~(3+),Gd~(3+),Dy~(3+),Nd~(3+)and x=0.02,0.04,0.06,0.08,0.1) with orthorhombic structure and narrow band gaps were successfully fabricated via sol-gel autocombustion method.All the substituted perovskites are found to exhibit excellent photocatalytic activity towards the oxidative degradation of dye molecules.An excellent increase in the rate constant values of pure perovskite(LaFeO_3) photocatalytic reactions is observed with the substitution of rare earth metal ions.Best results are obtained for LaNd_(0.1)Fe_(0.9)O_3 which exhibits around 7 times increase in the rate constant values for degradation reaction of SO(1.76×10~(-1) min~(-1))and RBY(1.69×10~(-1) min~(-1)) dyes.     

Performance modelling and analysis of double-pass packed-bed solar air heaters: an analytical framework

In this paper, the thermal performance of double-pass packed-bed solar air heaters is investigated theoretically. A suitable computer program is developed for the analytical solution of the mathematical model which involves the energy balance equations for the different components of the air heaters. Three different characteristics of the double-pass packed-bed solar air heaters are considered for the analysis. The results obtained from the analytical models are compared with the experimental model data obtained from the previous works and showed that good agreement is achieved.     

Energy-Effective and Secure Data Transfer Scheme for Mobile Nodes in Smart City Applications

Wireless Personal Communications - Mobile nodes are deployed at different locations in the smart city to collect meaningful information so captured data can be used as an input in different smart...     

Compression-Robust and Fuzzy-Based Feature-Fusion Model for Optimizing the Iris Recognition

Iris Recognition is gaining popularity in various online and offline authentication and multi-model biometric systems. The non-altering and non-obscuring nature of Iris have increased its reliability in authentication systems. The iris images captured in an uncontrolled environment and situation is the challenging issue of the iris recognition. In this paper, a compression robust and KPCA-Gabor fused model is presented to recognize the iris image accurately under these complexities. The illumination and noise robustness is included in this pre-processing stage for gaining the robustness and reliability against complex capturing. The effective compression features are generated as a phase pre-treatment vector using the Logarithmic quantization method. (Kernel Principal Component Analysis) KPCA and Gabor filters are applied to the rectified image for generating the textural features. The compression is also applied to Gabor and KPCA filtered images. The fuzzy adaptive content level fusion is applied to the compression image, KPCA-Compression, and Gabor-Compression iris-image. (K-Nearest Neighbors) KNN based mapping is used to this composite-fused and reduced feature set to recognize the individual. The proposed compression and fusion-feature based model is applied to CASIA-Iris, UBIRIS, and IITD datasets. The comparative evaluations against earlier approaches identify that the proposed model has improved the recognition accuracy and the reduction in error-rate is also achieved.

     

Modification of structural,thermal, and electrical properties of PVA by addition of silicon carbide nanocrystals

SiC‐PVA nanocomposite films, synthesized using solution‐casting technique were structurally characterized using X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. Morphological studies of the SiC‐PVA nanocomposite films were carried out using Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM). TEM analysis confirms that the size of SiC nanocrystals present in PVA matrix are 23 ± 9 nm, which is consistent with size calculated using XRD. SiC‐PVA nanocomposite films were further characterized for their thermal and electrical properties. Thermogravimetric/differential thermal analysis (TG/DTA) indicates that the char yield of nanocomposite films containing 3 wt % SiC nanocrystal is ～30% more than PVA. This increase in char yield is an indication of the potency of flame retardation of SiC‐PVA nanocomposite films. I‐V analysis reveals that Schottky mechanism is the dominant conduction mechanism which is responsible for the increase in conductivity of PVA with the addition of SiC nanocrystals. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42464.