Controlling the flow rate in an implantable rotary blood pump based on the physiological demand made by the body is important. Even though various methods to estimate the flow rate without using a flow meter have been proposed, no adequate method for measuring the blood viscosity, which is necessary for an accurate estimate of the flow rate, without using additional sensors or mechanisms in a noninvasive way, has yet been realized. We have developed a sensorless method for measuring viscosity in magnetically levitated rotary blood pumps, which requires no additional sensors or mechanisms. By applying vibrational excitation to the impeller using a magnetic bearing, we measured the viscosity of the working fluid by measuring the phase difference between the current in the magnetic bearing and the displacement of the impeller. The measured viscosity showed a high correlation (R(2) > 0.992) with respect to a reference viscosity. The mean absolute deviation of the measured viscosity was 0.12 mPa·s for several working fluids with viscosities ranging from 1.18 to 5.12 mPa·s. The proposed sensorless measurement method has the possibility of being utilized for estimating flow rate.
Direct conversion of CH 4 to syngas (H 2 and CO) via CH 4 partial oxidation was investigated using a narrow-gap co-axial dielectric barrier discharge reactor. Partial oxidation is initiated by electron impact dissociation of CH 4 , while complete oxidation is suppressed due to low temperature condition (200-400 °C): CH 4 conversion and selectivity for products were determined by the specific energy input (SEI) ambiguously, which is calculated by the input power (J/s) over the total flow rate (cm 3 /s), producing syngas via direct route with H 2 /CO = 0.8-1.3 and CO selectivity of 29-41%. However, H 2 was oxidized rather preferentially which subsequently produces oxidative species such as H 2 O 2 , HOO, and OH; H 2 oxidation was promoted by those species and H 2 selectivity decreased markedly. Suppression of H 2 oxidation is crucial issue to reach higher syngas yield with large H 2 /CO ratio.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.