Vibration-free miniature Joule-Thomson (JT) coolers are of interest for cooling small optical detectors for future space missions. The European Space Agency is interested in on-chip detector cooling for the temperature range 70¶K¶-¶250¶K. This is the topic of a new project at the University of Twente. In this project, the focus is on the integration of Micro-ElectroMechanical Systems (MEMS) bas...

We investigate the Northern Hemisphere Joule heating from several observational and computational sources with the purpose of calibrating a previously identified functional dependence between solar wind parameters and ionospheric total energy consumption computed from a global magnetohydrodynamic (MHD) simulation (Grand Unified Magnetosphere Ionosphere Coupling Simulation, GUMICS-4). In this pa...

C ryotherapy, or the use of freezing temperatures to elicit a specific tissue response, has a long history of safe and effective use in medicine. Cryothermal ablation results in discrete homogenous lesions that are sharply demarcated, with preserved ultrastructural tissue integrity and low propensity for thrombosis. Its unique safety profile is well established. Although cryoenergy has been use...

The temperature separation effects of vortex tubes have been widely studied in open systems, using mainly air or N2as the working fluid. When a tube is employed closed thermal system, more fluid choices, such as refrigerants, could be considered. Different to air, refrigerants quite varied thermal-physical properties, and research properties? influence on effect rather limited. Based CFD simula...

The present study investigates Joule heating in piezoresistive microcantilever sensors. Joule heating and thermal deflections are a major source of noise in such sensors. This work uses analytical and numerical techniques to characterise the Joule heating in 4-layer piezoresistive microcantilevers made of silicon and silicon dioxide substrates but with the same U-shaped silicon piezoresistor. A...

In this work, we have studied the influence of dc joule-heating thermal processing on the structure, magnetoimpedance (MI) and thermal properties of Co64Fe4Ni2B19-xSi8Cr3Alx (x = 0, 1, and 2) rapidly solidified melt-spun ribbons. The nanocrystallization process was carried out by the current annealing of as-spun samples at various current densities. As-spun and joule-heated samples were studied...

This article reports the evaluation of a Joule-Thomson (JT) cooling system that combines two custom micromachined components-a Si/glass-stack recuperative heat exchanger and a piezoelectrically actuated expansion microvalve. With the microvalve controlling the flow rate, this system can modulate cooling to accommodate varying refrigeration loads. The perforated plate Si/glass heat exchanger is ...

Heat recovery from an enhanced geothermal system (EGS) is a complex process involving heat transport in both fracture networks and rock formations. A comprehensive understanding of the ability to model underlying mechanisms important for success EGS commercialization but remains challenging practice due generally insufficient characterization reservoirs. In present study, we analyze extensively...