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• The transient liquid temperature was measured surrounding a growing bubble on oriented surfaces. • A highly oriented surface induces a larger bubble diameter with a lower departure frequency. • Liquid temperature distribution shows a progressive change on a perpendicular surface. • The heat transfer coefficient near the bubble interface is 1.3 times higher than that in bulk liquid. Nucleate boiling is perhaps one of the most efficient cooling methodologies due to its large heat flux with a relatively low superheat. Nucleate boiling often occurs on surfaces oriented at different angles; therefore, understanding the behavior of bubble growth on various surface orientations is of importance. Despite significant advancement, numerous questions remain regarding the fundamentals of bubble growth mechanisms on oriented surfaces, a major source of enhanced heat dissipation. This work aims to accurately measure three-dimensional (3D), space- and time-resolved, local liquid temperature distributions surrounding a growing bubble on oriented surfaces that quantify the heat transfer from the superheated liquid layer during bubble growth. The dual tracer laser-induced fluorescence thermometry technique combined with high-speed imaging captures transient 2D temperature distributions within a 0.3 ºC accuracy at a 30 μm resolution. The results show that the temperature close to the heated surface and bubble interface exhibits an acute transient behavior at the time of bubble departure, and the growing bubble works as a pump to remove heat from the surface with a temperature difference of up to 10 °C during its growth and departure. The experimental results are compared with data available in the literature to validate the accuracy of the technique. It was found that the heat transfer coefficient close to the bubble interface and heater is approximately 1.3 times higher than the heat transfer coefficient in the bulk liquid. [ABSTRACT FROM AUTHOR]

A device is proposed for the measurement of diffuse solar irradiance on tilted surfaces pointing-to as well as fixed on the equatorial direction. Most commercial devices are not designed for this purpose. Here, we present a specific design for a system based on a single multi-lobe shadow-ring that allows us to measure diffuse irradiance with several tilted pyranometers – from 60 to 90 degrees from the horizontal plane – and on different azimuth angles. This first prototype allows us to measure in the four cardinal directions. The ring is designed to minimize the covered celestial dome observed by each sensor. Moreover, the complete device needs a very small installation area and its simplicity means it is inexpensive and easy to operate. The measurements have subsequently to be corrected with a geometrical correction factor that takes into account the portion of the sky vault blocked by the shadow-ring. These measurements are essential for estimating solar potential on tilted surfaces – such as building façades – and for improving current anisotropic solar models, among many other applications. [ABSTRACT FROM AUTHOR]

Surface reconstruction is rarely been investigated to reconstruct 3D surfaces from data obtained from the internal human body organs. The 3D cloud of points can view objects in R space, however, it will not clearly demonstrate the curvatures of the outside of objects. Our 3D clouds of points are obtained from coronary artery trees. Each single-view angiogram can produce a 3D coronary artery tree. An approach to reconstruct 3D-oriented surfaces of 3D coronary artery trees is proposed. The approach leverages the Poisson problem for 3D surfaces from oriented data. The approach does not require the establishment of topological relations between adjacent points and involves no implicit parameter fitting. The approach consists of three stages: first, calculation of Euclidean distances between the clouds of points. Second, 3D-oriented data structuring. Finally, Poisson surface reconstruction of the 3D-oriented data (oriented cloud of points). An additional stage is added to measure the curvatures inside the 3D surfaces. Experimental evaluation has been done to raw of clinical data sets and results revealed that the proposed approach is efficient to reconstruct 3D surfaces of coronary artery trees. Results show that our proposed approach has high robustness for a variety of 3D cloud of points. The output surface can clearly display all the details and curvatures of the cloud of points. Our proposed algorithm of surface reconstruction plus the curvatures estimation is able to automatically indicate the locations of arteries and warn specialists of any abnormal medical cases of artery's penetration inside the heart. [ABSTRACT FROM AUTHOR]