By applying the micro-electro-mechanical-system (MEMS) fabrication technology, we developed a micro-thermal sensor to measure surface shear stress. The heat transfer from a polysilicon heater depends on the normal velocity gradient and thus provides the surface shear stress. However, the sensitivity of the shear-stress measurements in air is less than desirable due to the low heat capacity of a...

Vacuum-assist venous drainage (VAVD) can increase venous blood return during cardiopulmonary bypass (CPB) procedures. However, the negative pressure created in the closed cardiotomy reservoir can be transmitted to the oxygenator if a nonocclusive or centrifugal arterial pump is used, resulting in bubble transgression (BT) from the gas to blood compartment of the oxygenator. We analyzed the vacu...

Auger electron spectroscopy and thermoresistive methods are used to study the physical processes leading gas cooling of heated molybdenum filaments in a wide temperature range 350-1300 K pressures 760-10 -3 Torr, corresponding operating Pirani-type vacuum sensor. Nitrogen was as gas. It is shown that nitrogen atoms chemisorbed on surface do not contribute cooling, which occurs only due physisor...

Vacuum: continued on page 12 Sap exudation from maple trees is driven by the gradient in pressure from the inside to the outside of the tree. Under certain weather conditions (fluctuations above and below the freezing point of water) a dynamic period of tree pressure can be observed (Heiligmann et al. 2006, Chapeskie and Staats 2006). In most cases, the greater the difference in pressure, the g...

This work demonstrates a low-power, light-weight, and cost-efficient vacuum pressure sensor air leak detector based on 2 mm $\times2$ Cu/HfO 2 / notation="LaTeX">$\text{p}^{+}$ -Si...

Yttria-stabilized zirconia (YSZ) thin films were deposited using direct current (reactive and metallic) radio frequency magnetron sputtering. The effect of the deposition technique annealing treatment on microstructure crystallinity was assessed. Using produced in this work, oxygen gas sensors built their performance under vacuum conditions evaluated. All exhibited a cubic crystalline structure...