Hydrogen storage properties of Ti0.72Zr0.28Mn1.6V0.4 alloy prepared by mechanical alloying and copper boat induction melting

In the present study, two process techniques, mechanical alloying and innovative vacuum copper boat induction melting, were used to produce Ti_0.72Zr_0.28Mn_1.6V_0.4 alloy for hydrogen storage applications. The hydrogen absorption and desorption properties of the alloy were studied. The material structure and phases were characterized by XRD and SEM. The hydrogen absorption and desorption properties of the alloy were measured by an automatically controlled Sieverts apparatus. The results showed that the samples consisted of two main phases, C14 Lave phase and V-base solid solution phase. The maximum capacity of abs/desorption was achieved at mediate temperature (150 °C). The hydrogen capacity of the induction melted samples in various temperatures was higher than that for the samples produced by mechanical alloying method. The maximum absorption capacity of the induction melted and mechanically alloyed samples were 2 and 1.2 wt%, respectively. The maximum desorption capacity of the induction melted and mechanically alloyed samples were 0.45 and 0.1 wt%, respectively.     

Dynamic relationship between CO2 emissions,energy consumption and economic growth in three North African countries

This paper investigated the causal relationship between energy consumption (EC), carbon dioxide (CO₂) emissions and economic growth for three selected North African countries. It uses a panel co-integration analysis to determine this econometric relationship using data during 1980–2012. Recently developed tests for panel unit root and co-integration tests are applied. In order to test the Granger causality, a panel Vector Error Correction Model is used. The conservation hypothesis is found; the short run panel results show that there is a unidirectional relationship from economic growth to EC. In addition, there is a unidirectional causality running from economic growth to CO₂ emissions. A unidirectional relationship from EC to CO₂ emissions is detected. Findings shown that there is a big interdependence between EC and economic growth in the long run, which indicates the level of economic activity and EC mutually influence each other in that a high level of economic growth leads to a high level of EC and vice versa. Similarly, a unidirectional causal relationship from EC to CO₂ emissions is detected. This study opens up new insights for policy-makers to design comprehensive economic, energy and environmental policy to keep the economic green and a sustainable environment, implying that these three variables could play an important role in the adjustment process as the system changes from the long run equilibrium.     

On‐demand transmission model for remote visualization using image‐based rendering

Interactive distributed visualization is an emerging technology with numerous applications. However, many of the present approaches to interactive distributed visualization have limited performance because they are based on the traditional polygonal processing graphics pipeline. In contrast, image‐based rendering uses multiple images of the scene instead of a three‐dimensional geometrical representation, and so has the key advantage that the final output is independent of the scene complexity and depends on the desired final image resolution. Furthermore, the discrete nature of the light field dataset maps well to a hybrid solution, which can overcome the identified drawbacks. In this paper, we propose an on‐demand solution for efficiently transmitting visualization data to remote users/clients. This is achieved through sending selected parts of the dataset based on the current client viewpoint, and is done instead of downloading a complete replica of the light field dataset to each client, or remotely sending a single rendered view back from a central server to the user each time the user updates their viewing parameters. The on‐demand approach shows stable performance as the number of clients increases because the load on the server and the network traffic are reduced. Furthermore, detailed performance studies show that the proposed scheme outperforms the current solution in terms of interactivity measured in frames per second. Copyright © 2012 John Wiley & Sons, Ltd.