Predicting Natural Gas Hydrate Formation Temperature Using Levenberg-Marquardt Algorithm

In this study, two new correlations are proposed to predict the natural gas hydrate formation temperature as a function of pressure and specific gravity. The first correlation has been developed using Vandermonde matrix and the coefficients of the second correlation have been obtained by Levenberg-Marquardt algorithm. The error analysis shows the good performance of the two new proposed correlations to predict hydrate formation temperature compared to correlations presented earlier and also the experimental values.     

k-Connected Relay Node Deployment in Heterogeneous Wireless Sensor Networks

Wireless Personal Communications - Compressive sensing (CS) is a new sampling theory used in many signal processing applications due to its simplicity and efficiency. However, signal reconstruction...     

Deep convolution network for surveillance records super-resolution

Multimedia Tools and Applications - The aim of image super resolution (SR) is to recover low resolution (LR) input image or video to a visually desirable high-resolution (HR) one. The task of...     

Deep semantic preserving hashing for large scale image retrieval

Multimedia Tools and Applications - Hashing approaches have got a great attention because of its efficient performance for large-scale images. This paper, aims to propose a deep hashing method...     

Designing of some platinum or palladium-based nanoalloys as effective electrocatalysts for methanol oxidation reaction

Nano alloys contain noble metal nanostructures exhibit a wide theoretical and experimental interest in the field of fuel cells. Hard endeavors have been enhanced to improve the catalytic performance and minimize the usage of precious metals by alloying them with non-precious ones. Formation of bimetallic and trimetallic noble metal alloys with well-designed structures provide the opportunity to reach this goal. In this study, we first discuss the synthesis of noble metal alloy nanostructured thin films such as PtCu, PdCu, PtCu/reduced-graphene oxide (RGO), PdCu/RGO, PtCo, PtCo/RGO, PtPdCu and PtPdCu/RGO via a simple reduction of organometallic precursors including [PtCl₂ (cod)] and [PdCl₂(cod)], (cod = cis, cis-1,5-cyclooctadiene), in the presence of [Cu(acac)₂] and [Co(acac)₃] (acac = acetylacetonate) at oil/water interface and room temperature, including nanoparticles and nanosheets. Then the effects of the well-defined nanostructures on the improved electrochemical properties are outlined. Finally, we conclude that these non-precious bi and trimetallic alloy nanostructured thin films have better electrocatalytic performance than Pt monometallic thin films and other Pt nanostructures due to the geometric, electronic and stabilizer effect.     

A new approach to multi-objective optimisation method in PEM fuel cell

This paper presents an optimisation model for polymer electrolyte membrane fuel cell system based on simultaneous power maximisation and cost minimisation. The results show that, by employing appropriate relation between the objectives, the innovative design could be proposed. Genetic algorithm is applied to solve the optimisation problem. Power maximisation results reveal that at maximum amount of power (1.95 kW), unit cost of energy is $0.64. In contrast, minimisation of cost decreases unit cost of energy to $0.33. In this condition, output power is reduced approximately to 0.93 kW. To consider both optimisation problems concurrently, weighting method and Pareto set are employed. Our outcomes proposed that applying Pareto set to any optimisation problem leads to realistic decision-making. Eventually, sensitivity analysis is done on Pareto set, based on different Nafion membrane types and hydrogen cost variation.     

Experimental study of perforation of multi-layered targets by hemispherical-nosed projectiles

In this paper, perforation of single and three layered metallic targets by hemispherical-nosed cylindrical projectiles are studied experimentally. The circular targets of Al 1100 have a diameter of 220 mm and the hemispherical-nosed projectiles are silver steel cylinders with a mass of 12.15 g which are hardened to 56RC. The single layer target is 3 mm thick and the thicknesses of layers of the three layered targets are 0.5, 1 and 1.5 mm. The multi-layered targets are tested both when the layers are in-contact and spaced (with air gaps). Tests are carried out using a one stage gas gun. The ballistic limit velocity is obtained and the effects of order of layers and the width of air gaps between them on the ballistic limit velocity are investigated. The results show that the single layer targets have greater ballistic limit velocities than multi-layered targets. Furthermore, the ballistic limit velocity of in-contact layered targets is greater than that of spaced layered targets.