Woodcock C.,Rensselaer Polytechnic Institute |
Houshmand F.,Rensselaer Polytechnic Institute |
Plawsky J.,Rensselaer Polytechnic Institute |
Izenson M.,Creare |
And 4 more authors.
Thermomechanical Phenomena in Electronic Systems -Proceedings of the Intersociety Conference | Year: 2014
A novel approach to embedded electronics cooling with a multi-phase microfluidic heat sink termed the Piranha Pin-Fin (PPF) is presented. Several first-generation PPF devices, as well as plain-channel and solid pin-fin heat sinks, have been fabricated and experimentally tested under single-phase adiabatic conditions. Details of the PPF device geometry and microfabrication process are provided. Plots showing pressure drop and friction factor are also provided. © 2014 IEEE.
Swan J.G.,One Medical Center Dr |
Wilbur J.C.,Creare |
Moodie K.L.,One Medical Center Dr |
Kane S.A.,One Medical Center Dr |
And 6 more authors.
Journal of Applied Physiology | Year: 2014
Using dual-frequency ultrasound (DFU), microbubbles (<10 (xm diameter) have been detected in tissue following decompression. It is not known if these micro-bubbles are the precursors for B-mode ultrasound-detectable venous gas emboli (bmdVGE). The purpose of this study was to determine if microbubbles could be detected intravascularly postdecompression and to investigate the temporal relationship between microbubbles and larger bmdVGE. Anesthetized swine (n = 15) were exposed to 4.0-4.5 ATA for 2 h, followed by decompression to 0.98 ATA. Microbubble presence and VGE grade were measured using DFU and B-mode ultrasound, respectively, before and for 1 h postdecompression, approximately every 4-5 min. Microbubbles appeared in the bloodstream postdecompression, both in the presence and absence of bmdVGE. In swine without bmdVGE, microbubbles remained elevated for the entire 60-min postdecompression period. In swine with bmdVGE, microbubble signals were detected initially but then returned to baseline. Microbubbles were not detected with the sham dive. Mean bmdVGE grade increased over the length of the postdecompression data collection period. Comparison of the two response curves revealed significant differences at 5 and 10 min postdecompression, indicating that microbubbles preceded bmdVGE. These findings indicate that decompression-induced microbubbles can 1) be detected intravascularly at multiple sites, 2) appear in the presence and absence of bmdVGE, and 3) occur before bmdVGE. This supports the hypothesis that microbubbles precede larger VGE bubbles. Micro-bubble presence may be an early marker of decompression stress. Since DFU is a low-power ultrasonic method, it may be useful for operational diving applications. Copyright © 2014 the American Physiological Society.