The oral retention of fluoride (F) following the topical application of a newly developed APF foam was compared with a conventional APF gel. Twenty adults aged 16-26 years participated in the study. Ten of the subjects received the F foam and gel treatments, on separate occasions, with a saliva ejector while another 10 subjects received the same treatment without saliva ejector. Approximately 4...

Dual fuel engines with LNG as have become a feasible solution for ship power units in the current situation, but their efficiency needs to be further enhanced meet increasingly stringent emission requirements. This paper designs dual-loop system, including supercritical CO2 cycle and thermally driven ejector refrigeration cycle, recovering exhaust gas charge air heat of marine dual engine. The ...

The performance of Joule-Thomson (JT) cryocoolers can be improved by introducing ejectors. Ejectors with various geometric features have been proposed and investigated for cryogenic cooling in earlier studies, but only limited research is done on ejectors a nozzle throat diameter less than 1 mm. In this paper, we present miniature ejector 162 ?m that was measured using X-ray computed tomography...

Increasing production and recovery from mature oil and gas fields often requires a boosting system. Introducing natural gas ejectors can be considered to be a cost-effective way for boosting the production of low-pressure natural gas wells. The CFD technique was employed to investigate the effects of the geometrical factors of natural gas ejectors, the optimal geometrical factors were obtained ...

This paper studies the impact of installing noise-suppressing deflector vanes in the bypass flow on the aerodynamic performance of the dual-stream supersonic nozzle of a turbofan engine by using a three-dimensional Reynolds-averaged Navier-Stokes computer program. A series of nozzle configurations using a single pair or double pairs of vanes with NACA0012, NACA4412, and NACA7514 airfoil profile...

Cavitation and turbulence in a diesel injector nozzle has a great effect on the development and primary breakup of spray. However, the mechanism of the cavitation flow inside the nozzle and its influence on spray characteristics have not been clearly known yet because of the internal nozzle flow complexities. In this paper, a comprehensive numerical simulation is carried out to study the intern...

compressible gas flow inside a convergent-divergent nozzle and its exhaust plume atdifferent nozzle pressure ratios (npr) have been numerically studied with severalturbulence models. the numerical results reveal that, the sst k–ω model give the bestresults compared with other models in time and accuracy. the effect of changes in value ofdivergence half-angle (ε ) on the nozzle performance, thru...

A device for ejecting several streams based on the flow of a stream in slit gap and designed mixing liquid gaseous media is considered