Modelling the damage evolution in unidirectional hybrid laminates

Although composite materials are durable, strong and light, their brittleness limits their use in several industrial applications. The lack of ductility of composites can be overcome by hybridisation where low strain materials (LSM) are sandwiched between two layers of high strain materials (HSM). Hybridisation tends to improve composite properties by acting either on the overall mechanical properties or on the damage propagation mechanisms leading to failure. UD hybrid composites have complex failure mechanisms including multiple interacting damage modes, such as ply fragmentation and interface delamination. The damage mechanisms in UD hybrid composites varies with the thickness ratio of LSM/HSM. To study the behaviour of UD hybrid composites in different load and boundary conditions, a numerical model is required. The aim of this study is to simulate the damage evolution in unidirectional hybrid carbon/glass and carbon/carbon composites subjected to tensile loading by finite element models

Phase equilibrium modeling of structure H clathrate hydrates of methane + water "insoluble" hydrocarbon promoter using group contribution-support vector machine technique

In this work, the group contribution (GC) method is coupled with the least-squares support vector machine (LSSVM) mathematical algorithm to develop a model for representation/prediction of the dissociation conditions of structure H (sH) clathrate hydrates of methane with 21 hydrocarbon promoters namely as water "insoluble" promoters. Almost all of available literature data are studied to present a reliable model validated by the following statistical parameters: absolute average relative deviations (AARD) of the represented/predicted dissociation pressures from the reported experimental values: about 1.6%, and squared correlation coefficient: 0.99. © 2011 American Chemical Society.Ali Eslamimanesh, Farhad Gharagheizi, Amir H. Mohammadi, Dominique Richon, Mohammad Illbeigi, Alireza Fazlali, Amir Ahmad Forghani, and Mohammad Yazdizade

Keggin heteropolyacid supported on BN and C3N4: Comparison between catalytic and photocatalytic alcohol dehydration

The Keggin heteropolyacid (HPA), H3PW12O40 (PW12) has been supported on commercial boron nitride (BN) and two types of home prepared carbon nitride (C3N4). The supported PW12 was used in the gas-solid (photo)catalytic 2-propanol dehydration reaction to give propene at atmospheric pressure and temperatures in the range 70–120 °C and resulted more active than the pristine PW12. Reaction rate increased by increasing the temperature. Noticeably, the propene formation rate was higher by irradiating the catalytic system. The PW12/BN material resulted more active than PW12/C3N4. The acidity of the HPA cluster accounts for the catalytic role, whereas both the acidity and the redox properties of the HPA species were responsible for the increase of the reaction rate in the photo-assisted catalytic reaction.Peer reviewe

Efficient datapath merging for the overhead reduction of run-time reconfigurable systems

High latencies in FPGA reconfiguration are known as a major overhead in run-time reconfigurable systems. This overhead can be reduced by merging multiple data flow graphs representing different kernels of the original program into a single (merged) datapath that will be configured less often compared to the separate datapaths scenario. However, the additional hardware introduced by this technique increases the kernels execution time. In this paper, we present a novel datapath merging technique that reduces both the configuration and execution times of kernels mapped on the reconfigurable fabric. Experimental results show up to 13% reduction in the configuration and execution times of kernels from media-bench workloads, compared to previous art on datapath merging. When compared to conventional high-level synthesis algorithms, our proposal reduces kernels configuration and execution times by up to 48%.Software Computer TechnologyElectrical Engineering, Mathematics and Computer Scienc