Self-tracking planar concentrator using a solar actuated phase-change mechanism

2013 ◽  
Author(s):  
Eric J. Tremblay ◽  
Volker Zagolla ◽  
Damien Loterie ◽  
Christophe Moser
Keyword(s):  
Phase Change ◽  
Change Mechanism

scholarly journals New Volume Change Mechanism Using Metal Bellows for Buoyancy Control Device of Underwater Robots

ISRN Robotics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Koji Shibuya ◽  
Sho Yoshii
Keyword(s):  
Phase Change ◽  
Volume Change ◽  
Control Method ◽  
Control Device ◽  
Paraffin Wax ◽  
Underwater Robots ◽  
Nichrome Wire ◽  
Change Mechanism ◽  
Metal Bellows ◽  
Buoyancy Control

We propose a new volume change mechanism using a metal bellows for a buoyancy control device of underwater robots and vehicles. Our proposed buoyancy control method utilizes the volume change caused by the phase-change of materials. We chose paraffin wax as a phase-change material because its volume change exceeds other candidates. Our proposed device consists of a metal bellows and an aluminum housing that contains paraffin wax and water. The paraffin wax is heated and cooled by a nichrome wire and a peltier device. We conducted two experiments and confirmed that the heat sink in the aluminum housing increases the speed of the buoyancy change and that the thickness of the air layer is crucial for efficient insulating. Then, we built a prototype robot with the four devices and confirmed that the robot can change its buoyancy up to its maximum value.

New Mechanisms for Cryogenic Solid-Gas Sublimation Refrigeration

2015 ◽  
pp. 106-154
Author(s):  
Lin Chen
Keyword(s):  
Numerical Modeling ◽  
Low Temperature ◽  
Phase Change ◽  
Future Research ◽  
Two Phase ◽  
Food Engineering ◽  
Change Mechanism ◽  
Physical Problems ◽  
Industrial Sectors ◽  
Fast Cooling

Sublimation is one phase change mechanism which usually happens under low-to-moderate temperatures and at the same time large amounts of latent heat is absorbed or released. Low temperature sublimation has been proposed in a lot of applications as one useful fast cooling/refrigeration mechanisms, such as medical cooling, food engineering, chemical synthesis, domestic cooling and many industrial sectors. In this brief chapter, the basic mechanisms of static sublimation process and sublimation two-phase flows are clarified and analyzed first, which covers the theoretical and physical problems of sublimation phase-change. Then the previous studies are classified into numerical modeling and experimental verifications. Representative refrigeration systems are also introduced and compared in this chapter, which may give useful indications for future innovations in this field. Future research focuses are also summarized and proposed in this chapter.

scholarly journals Modeling of MEMS Mirrors Actuated by Phase-Change Mechanism

Micromachines ◽  
2017 ◽  
Vol 8 (5) ◽  
pp. 138 ◽  
Author(s):  
David Torres ◽  
Jun Zhang ◽  
Sarah Dooley ◽  
Xiaobo Tan ◽  
Nelson Sepúlveda
Keyword(s):  
Phase Change ◽  
Change Mechanism

scholarly journals A Phase-Change Mechanism of GST-SL Based Superlattices upon Sb Flipping

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 360
Author(s):  
Teng Sun ◽  
Furong Liu ◽  
Jicheng Guo ◽  
Gang Han ◽  
Yongzhi Zhang
Keyword(s):  
Phase Change ◽  
Length Distribution ◽  
Melting Process ◽  
Ab Initio Molecular Dynamics ◽  
Electron Localization ◽  
Switching Model ◽  
Change Mechanism ◽  
Fast Switching ◽  
Reversible Phase ◽  
Bond Length Distribution

Reversible phase-change behaviors of Ge–Sb–Te based superlattices (GST-SL) were studied by ab initio molecular dynamics (AIMD) simulations based on three models containing Ge/Sb intermixing, namely the Petrov-mix, Ferro-mix, and Kooi-mix models. The flipping behavior of Sb atoms was found in all the three GST-SL models in the melting process. Among them the Kooi-mix model exhibited the best stability, and the analyses of bond length distribution and electron localization function provided a better explanation on the phase transition of GST-SL. Finally, we proposed a fast switching model for GST-SL based on Sb flipping.

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