Mold Filling Simulation of Semi-Solid Magnesium Alloys

Peer reviewed: YesNRC publication: Ye

Energy Harvesting Using Piezoelectric Thick Films Fabricated by a Sol-Gel Process

Peer reviewed: YesNRC publication: Ye

Cloud computing: survey on energy efficiency

International audienceCloud computing is today’s most emphasized Information and Communications Technology (ICT) paradigm that is directly or indirectly used by almost every online user. However, such great significance comes with the support of a great infrastructure that includes large data centers comprising thousands of server units and other supporting equipment. Their share in power consumption generates between 1.1% and 1.5% of the total electricity use worldwide and is projected to rise even more. Such alarming numbers demand rethinking the energy efficiency of such infrastructures. However, before making any changes to infrastructure, an analysis of the current status is required. In this article, we perform a comprehensive analysis of an infrastructure supporting the cloud computing paradigm with regards to energy efficiency. First, we define a systematic approach for analyzing the energy efficiency of most important data center domains, including server and network equipment, as well as cloud management systems and appliances consisting of a software utilized by end users. Second, we utilize this approach for analyzing available scientific and industrial literature on state-of-the-art practices in data centers and their equipment. Finally, we extract existing challenges and highlight future research directions

Ultrasonic monitoring of die-casting process using clad buffer rod sensor

In-line monitoring of die-casting of aluminum (A356, A357, 86S), magnesium (AZ91) and a metal matrix composite (Gra-NiRTM 6S:3G) will be monitored using the reflection coefficient obtained by using an ultrasonic technique, the pulse/echo. For each of the materials enumerated above, the average temperature of the mold through its thickness, the end of filling of the part, the solidification of the part in the cavity of the mold, the gap and/or the detachment of the part, the sound velocity and the attenuation of the material will be measured by this ultrasonic technique during the process.For the materials the melt temperature will not exceed 600°C because the casting is made at the semi-solid state, between the solidus and liquidus, of the materials. A novel high performance buffer rod with a cooling system is integrated into the die. Therefore, ultrasonic measurements can be carried out with high signal-to-noise ratio at elevated temperatures

Measurement of the heat transfer coefficient under transient and steady state conditions during magnesium semi-solid casting process

Peer reviewed: YesNRC publication: Ye