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Breast cancer is the most prevalent form of cancer in women with over 266,000 new cases diagnosed every year in the United States. The various methods used for breast cancer screening range in accuracy and cost; however, there is no easily reproducible, reliable, low-cost, nonradiative screening modality currently available, especially for dense breast tissue. Steady-state infrared imaging (IRI) is promising in this area as it is unaffected by tissue density and has the potential to detect tumors by measuring and capturing the thermal profile on the breast surface induced by increased blood perfusion and metabolic activity associated with the tumor. In our proposed clinical IRI and simulation approach (CIRIS™), women with biopsy-proven breast cancer are imaged with IRI in the prone position. The prone position is able to provide a thermal profile of the entire breast without any gravitational deformation or thermal abnormalities in the inframammary fold. A digital model, created using clinical images, is thermally simulated through a commercially available software using known tumor characteristics obtained from the available magnetic resonance imaging (MRI) data. The resulting surface thermal profile is compared with the IRI images. In the three cases discussed here, the digital model was able to accurately predict the breast surface temperature distribution, showing the promise of this approach in breast cancer screening. This preliminary work is expected to lead the way for a larger clinical study in the future to establish IRI as an adjunctive screening technique.

The increasing demand for designing effective cooling solutions in high power density electronic components has resulted in exploring advanced thermal management strategies. Over the past decade, phase-change cooling has received widespread recognition due to its ability to dissipate large heat fluxes while maintaining low temperature differences. In this paper, a radial flow boiling configuration through a central inlet was studied. This configuration is particularly suited for chip cooling application. Two heat transfer surfaces with (a) radial microchannels, and (b) offset strip fins were fabricated and their flow boiling performance with distilled water was obtained. Furthermore, the effect of the liquid flow rate on the boiling performance and enhancement mechanisms was also investigated in this study. At a flow rate of 240 mL/min, a maximum heat flux of 369 W/cm2 at a wall superheat of 49 °C and a pressure drop of 59 kPa was achieved with the radial microchannels, while the offset strip fins achieved a maximum heat flux of 618 W/cm2 at a wall superheat of 20 °C. Increasing the flow rate to 320 mL/min resulted in a heat flux of 897 W/cm2 demonstrating the potential of using a radial configuration for enhancing the boiling performance. The increase in flow cross-sectional area was shown to be responsible for the reduced pressure drop when compared to straight microchannel configurations. The high-speed imaging incorporated in each test provided valuable insight and understanding into the flow patterns and underlying mechanism in these geometries. With the ease of implementation, highly stable flow, and further optimization possibilities with different microchannel and taper configurations, the radial geometry is expected to provide significant performance enhancement well beyond a critical heat flux (CHF) of 1 kW/cm2.

Flow boiling has the ability to remove high heat fluxes while maintaining a low wall superheat. Various researchers have developed enhanced microchannel geometries to improve the heat transfer performance of the system. Recently, a number of new studies have used the increasing flow cross-sectional area concept to overcome flow instabilities and record high CHF. In this work, a new geometry is experimentally investigated utilizing a radial cross-section, which provides the increasing fluid flow cross-sectional area in the flow direction. The flow boiling performance is studied using radial microchannels and water as the working fluid. Four different flow rates ranging from 120–400 mL/min are studied for this new geometry. Heat transfer performance (boiling curve and heat transfer coefficient) and pressure drop characteristics are discussed for all flow rates. Furthermore, the work is supported by high speed visualization of the bubble dynamics. The boiling performance obtained is compared to the existing data in the literature.