Experimental and CFD Characterization of a Double-Orifice Synthetic Jet Actuator for Flow Control

The paper presents a joint experimental and numerical characterization of double-orifice synthetic jet actuators for flow control. Hot-wire measurements of the flow field generated by the device into a quiescent air environment were collected. The actuation frequency was systematically varied to obtain the frequency response of the actuator; its coupled resonance frequencies were detected and the velocity amplitude was measured. Direct numerical simulations (DNS) of the flow field generated by the device were subsequently carried out at the actuation frequency maximizing the jet output. The results of a fine-meshed parametric analysis are outlined to discuss the effect of the distance between the orifices: time-averaged flow fields show that an intense jet interaction occurs for small values of the orifice spacing-to-diameter ratio; phase-averaged velocity and turbulent kinetic energy distributions allow to describe the vortex motion and merging. A novel classification of the main regions of dual synthetic jets is proposed, based on the time- and phase-averaged flow behaviour both in the near field, where two distinct jets converge, and in the far field, where an unique jet is detected. The use of three-dimensional DNS also allows to investigate the vortex merging for low values of the jet spacing. The work is intended to provide guidelines for the design of synthetic jet arrays for separation control and impinging configurations.

A Young Girl with Barely Symptomatic Congenital Mitral Valve Disease

Congenital mitral valve disease or malformation may be isolated or associated with other cardiac anomalies. Mitral valve may affect its different segments during development. This anomaly is due to mitral valve with a single fibrous annulus with two orifices (Double orifices mitral valve) that open into the left ventricle. It may be associated with stenosis and or mitral regurgitation. Here we describe a 17 years young girl with palpitation and shortness of breath on moderate to severe exertion. Examination of the cardiovascular system, chest including precordium revealed no abnormality. She is acyanotic and there is no clubbing. On Trans thoracic Echocardiogram isolated double orifice mitral valve was found with no other associated congenital anomalies. Cardiovasc j 2021; 14(1): 79-81

Rare double orifice mitral valve malformation associated with bicuspid aortic valve in Turner syndrome: diagnosed by a series of novel three-dimensional echocardiography and literature review

Background Patients with both double orifice mitral valve (DOMV) and bicuspid aortic valve (BAV) malformation are rare. Although DOMV or BAV can be detected in some genetic syndromes, it has not been reported to simultaneously appear in Turner syndrome (TS). TrueVue, TouchVue, and TrueVue Glass are the latest technologies in advanced three-dimensional echocardiography (3DE), which is an important information supplement to two-dimensional echocardiography (2DE) for the diagnosis of congenital cardiac malformations. Herein we report the novel use of the above-mentioned technologies in the diagnosis and evaluation of a rare, combined valve malformation. Meanwhile, we also reviewed the literature for cases involving both DOMV and BAV and their association with various genetic syndromes. Case presentation We present the case of a 5-year-old girl diagnosed with TS because of a developmental delay. DOMV and BAV were found through echocardiographic examination. Three-dimensional transthoracic echocardiography as well as a series of novel advanced techniques were applied to clearly display the spatial structure of all tiers of the mitral valve apparatus, aortic valve, and arch to facilitate an accurate diagnosis. Conclusions This is the first case in which both DOMV and BAV were associated with TS. Innovative TrueVue and TrueVue Glass offer unprecedented photographic stereoscopic images, while TouchVue technology greatly improved the ultrasonic diagnostic workflow and the diagnostic performance of rare valve malformations by adding virtual light sources to display realistic light-shadow effects.

Synchronized resistive-pulse analysis with flow visualization for single micro- and nanoscale objects driven by optical vortex in double orifice

Resistive-pulse analysis is a powerful tool for identifying micro- and nanoscale objects. For low-concentration specimens, the pulse responses are rare, and it is difficult to obtain a sufficient number of electrical waveforms to clearly characterize the targets and reduce noise. In this study, we conducted a periodic resistive-pulse analysis using an optical vortex and a double orifice, which repetitively senses a single micro- or nanoscale target particle with a diameter ranging from 700 nm to 2 $$\mu$$ μ m. The periodic motion results in the accumulation of a sufficient number of waveforms within a short period. Acquired pulses show periodic ionic-current drops associated with the translocation events through each orifice. Furthermore, a transparent fluidic device allows us to synchronously average the waveforms by the microscopic observation of the translocation events and improve the signal-to-noise ratio. By this method, we succeed in distinguishing single particle diameters. Additionally, the results of measured signals and the simultaneous high-speed observations are used to quantitatively and systematically discuss the effect of the complex fluid flow in the orifices on the amplitude of the resistive pulse. The synchronized resistive-pulse analysis by the optical vortex with the flow visualization improves the pulse-acquisition rate for a single specific particle and accuracy of the analysis, refining the micro- and nanoscale object identification.

Bilateral coronary ostial atresia in a patient with pulmonary atresia and ventricular septal defect

This is a case of a female infant with bilateral coronary ostial atresia associated with pulmonary atresia and ventricular septal defect. She developed coronary ischemia at 1-month of age, when she underwent an aortopulmonary shunt and an aorta-right ventricle shunt. The double-orifice tricuspid valve was separating the right ventricle from the left ventricle. She required extracorporeal cardiopulmonary support because of ventricular dysfunction and mitral regurgitation. Although she was temporarily weaned off the support after mitral valvuloplasty, she died from multiple organ failure. To the best of our knowledge, bilateral coronary ostial atresia associated with pulmonary atresia with ventricular septal defect has not been reported previously.