ACO–EEOLSR: enhanced energy model based link stability routing protocol in mobile ad hoc networks

A mobile ad hoc network (MANET) has abundant mobile nodes that are free to communicate independently in many locations. Many existing energy models address the inadequacy of resources based on Ad hoc On-demand Multipath Distance Vector and Optimized Link State Protocol (OLSP) routing protocols for MANET along with various parameters. The architecture of energy-efficient routing mechanisms is a challenging problem in a MANET. In this work, a novel energy-aware routing model is introduced for MANET comprising an ant colony optimization (ACO) enhanced approach to energy-efficient-optimized link state routing (named ACO–EEOLSR). Initially, the route discovery is progressed by means of neighbor estimation and also with the authentication of link stability. Parameters such as energy, distance, and hop count are employed as willingness nodes, where both the energy and distance are entrenched through the OLSP. Consequently, the hop count is applied via the ACO system that is beneficial for link stability. After the acceptance of an acknowledgement, the hop count is authorized for further performance analysis. This approach increases the Quality of Service and also uses less energy compared to other energy models. The accomplished simulation upshot depicts that the ACO–EEOLSR outperforms the EEOLSR scheme with respect to the performance metrics of energy consumption, packet delivery ratio, total remaining time, average network lifetime, and a variance of energy.     

Effect of carbide ceramics and coke on the properties of dispersion strengthened aluminium-silicon7-magnesium hybrid composites

In this study, aluminium-silicon7-magnesium alloy was reinforced with carbide ceramics (silicon carbide and boron carbide) and coke microparticles. The composite samples (S1, S2, and S3) with 4 %, 8 %, and 12 % by weight of silicon carbide and boron carbide microparticles and 8 % by weight of coke micro particles respectively, were prepared through the ultrasonic assisted melt-stir casting route. It was observed from the literature that only a few research works reported the cumulative effect of adding these micro-particulate reinforcements within aluminium-silicon7-magnesium alloy. The microstructural evaluation revealed uniform dispersion of particulate reinforcements. Area energy dispersive x-ray spectroscopy scan results proved the presence of the reinforcement particles as heterogeneous phases at distinct zones. The samples undergone tensile tests failed under the brittle fracture mode. The ultimate tensile strength of the composites improved by about 27.4 %, the % elongation improved by about 6.8 %, and Vickers microhardness dropped 1.9 % to the maximum. Dimples were observed in the fracture morphology analysis and it was mainly due to the mixed ductility of the sample S2. An abrasive wear mechanism was observed in the worn-out sample S2. The wear rate decreased significantly with an increase in weight fraction of the reinforcements.     

Investigations on the Effect of Tungsten Carbide and Graphite Reinforcements during Spark Erosion Machining of Aluminium Alloy (AA 5052) Hybrid Composite

Silicon - Reinforcements introduced to metal matrix composites are known for their inherent properties like corrosion resistance, wear resistance and machinability. This study deals with the...     

Enhanced DSSC performance with high surface area thin anatase TiO2 nanoleaves

Thin anatase TiO₂ nanoleaves (NLs) with high surface area (∼93 m²/g) are synthesized by hydrothermal route and dye-sensitized solar cells (DSSC) made using such NLs are compared with those made with hydro-thermally synthesized TiO₂ nanoparticles and the Degussa P25 powder. The NLs-based DSSCs show increment of 16% and 24% in the total conversion efficiency over the cells made with NPs and P25 respectively. Interestingly, the highest increment in the conversion efficiency (∼35%) is achieved for cells made using a 50:50 (wt/wt) mixture of NLs and NPs. In this case the dye loading is found to be >50% higher than the case of NP films. Moreover the DC resistance of diffusion of in electrolyte (as revealed by the electrochemical impedance spectroscopy) is substantially lower than the NP film case, other cell parameters being nominally comparable.     

Oxide-ion conductivity of calcia- and yttria-stabilized zirconias prepared by a rapid-combustion route

Calcia- and yttria-stabilized zirconias have been synthesised by a novel rapid-combustion route. The oxide-ion conductivities of these stabilized zirconias are comparable to these of commercially prepared samples. Variations in grain boundary impedance of calcia- and yttria-stabilized zirconias with composition and temperature are presented.     

Growth and characterization of dl-Alanine — A new NLO material from the amino acid family

Single crystals of dl-Alanine (C₃H₇NO₂), one among the rare amino acid racemates crystallizing in a non-centrosymmetric space group and a new NLO material, were grown from aqueous solution by slow evaporation method. They were characterized by single crystal X-ray diffraction. Fourier transform infrared spectroscopy (FTIR) showed the presence of the different functional groups. The thermal stability and decomposition of the sample was studied by thermal analysis (TGA/DTA). The optical transparency was studied by UV–Vis–NIR spectral analysis. The above experimental results showed that dl-Alanine is stable up to 280 °C and transparent in the region of 220 nm–1100 nm. The second harmonic generation (SHG) efficiency was determined using Kurtz and Perry method and found to be 1.7 times higher than that of standard KDP.