Quantitative Monitoring of Dynamic Blood Flows Using Coflowing Laminar Streams in a Sensorless Approach

Determination of blood viscosity requires consistent measurement of blood flow rates, which leads to measurement errors and presents several issues when there are continuous changes in hematocrit changes. Instead of blood viscosity, a coflowing channel as a pressure sensor is adopted to quantify the dynamic flow of blood. Information on blood (i.e., hematocrit, flow rate, and viscosity) is not provided in advance. Using a discrete circuit model for the coflowing streams, the analytical expressions for four properties (i.e., pressure, shear stress, and two types of work) are then derived to quantify the flow of the test fluid. The analytical expressions are validated through numerical simulations. To demonstrate the method, the four properties are obtained using the present method by varying the flow patterns (i.e., constant flow rate or sinusoidal flow rate) as well as test fluids (i.e., glycerin solutions and blood). Thereafter, the present method is applied to quantify the dynamic flows of RBC aggregation-enhanced blood with a peristaltic pump, where any information regarding the blood is not specific. The experimental results indicate that the present method can quantify dynamic blood flow consistently, where hematocrit changes continuously over time.

Microfluidic Device Engineered to Study the Trafficking of Multiple Myeloma Cancer Cells Through the Sinusoidal Niche of Bone Marrow

Multiple myeloma (MM) is an incurable B cell malignancy characterized by the accumulation of monoclonal abnormal plasma cells in the bone marrow (BM). It has been a significant challenge to study the spatiotemporal interactions of MM cancer cells with the embedded microenvironments of BM. Here we report a microfluidic device which was designed to mimic several physiological features of the BM niche: (1) sinusoidal circulation, (2) sinusoidal endothelium, and (3) stroma. The endothelial and stromal compartments were constructed and used to demonstrate the device’s utility by spatiotemporally characterizing the CXCL12-mediated egression of MM cells from the BM stroma and its effects on the barrier function of endothelial cells (ECs). We found that the egression of MM cells resulted in less organized and loosely connected ECs, the widening of EC junction pores, and increased permeability through ECs, but without significantly affecting the number density of viable ECs. The results suggest that the device can be used to study the physical and secreted factors determining the trafficking of cancer cells through BM. The sinusoidal flow feature of the device provides an integral element for further creating systemic models of cancers that reside or metastasize to the BM niche.

Performance analysis of AS-SOFC fuel cell combining single and sinusoidal flow field: numerical study

The performance of a solid oxide fuel cell (SOFC) was examined using 3D computational fluid dynamics to model mass and heat flows inside the channels. In the present investigation, a SOFC fuel cell with a new flow field based on a sinusoidal flow has been studied. The latter was tested and compared with a single flow using ANSYS FLUENT. The obtained results showed that at a given operating voltage, the maximum power for the sinusoidal and the single flow fields were 1.43 and 1.35 W/cm2, respectively. By taking in addition, into account the concentration, activation and Ohmic losses; it was noticed that the distribution of velocity and temperature for the sinusoidal flow led to bettered results. Furthermore, it was observed that the maximum use of H2 mass fraction consumed in sinusoidal and single flow field designs were 60% and 55% respectively. Similarly, the highest H2O mass fraction values produced for the sinusoidal and single flow designs were 42% and 34% respectively. This model was validated and confronted to previous data. The present results agree well with reported studies in literature.

Experimental Study of Mean Flow Characteristics in the Near Field of Wedge-Shaped Swirling Jets

In this investigation experiment was carried out in 80 mm diameter swirling pipe jet, where swirl was generated by attaching wedge-shaped helixes in the pipe. All measurements were taken at Re 5.3e4. In the plain pipe jet the potential core was found to exist up to x/D=5 but in the swirling jet there was no existence of potential core. The mean velocity profiles were found to be influenced by the presence of wedge-shaped helixes in the pipe. The velocity profiles indicated the presence of sinusoidal flow field in the radial direction existed only in the near field of the jet. This flow field died out after x/D=3 and the existence of jet flow diminished after x/D=5.

Effect of Sinusoidal Oscillatory Flow on a Vertical Wall-Mounted Cylinder

The purpose of this study is to numerically investigate the bed shear stress and near-bed mixing due to coherent vortex structures in the vicinity of a vertically wall-mounted circular cylinder subject to an imposed finite-depth oscillatory sinusoidal flow. Previous studies reveal that the Keulegan–Carpenter (KC) number influences the formation of lee-side wake vortex structures as well as the horseshoe vortex in front of a cylinder. Therefore, parametric studies in a moderately wide range of KC from 5 to 20 are numerically performed. In the present study, Direct Numerical Simulation (DNS) is conducted using the open-source software, OpenFOAM, that solves the three-dimensional unsteady incompressible Navier-Stokes equations using finite volume method. Nondimensional parameters used in the simulations are carefully chosen to represent the real physics. The numerical solutions are first validated using an analytical solution for the oscillating Stokes flow and the results are then systematically and quantitatively compared with the experimental measurements. The results show that the lee-side wake is significantly influenced by KC, and distinctive types of the lee-side wake are generated and classified based on KC. It is also found that both KC and the ratio of the thickness of the Stokes boundary layer to the water depth are heavily associated with the stability of the lee-side wake. In addition, the simulated size and lifespan of the horseshoe vortex agree well with the experimental data.

Single-Phase to Three-Phase Unified Power Quality Conditioner for Power Factor Improvement Using Fuzzy Logic Controller

This paper manages the arrangement of a nearby three stage four wire (3P4W) electrical power appropriation framework (EPDS), utilizing a solitary to three stage bound together power quality conditioner (UPQC) topology with fluffy controller , called UPQC 1Ph to 3Ph. The topology is shown for applications in country or remote zones in which, for financial reasons, just EPDS with single wire earth return are open to the buyer. Since the utilization of three stage loads is expanding in these regions, access to a three stage dispersion framework ends up dominant. By embracing a double pay methodology, the proposed UPQC 1Ph to 3Ph is capable of depleting from the single stage electrical framework a sinusoidal flow and in stage with the voltage, coming about high power factor. Moreover, the framework is likewise ready to stifle lattice voltage sounds, just as to make up for different aggravations, for example, voltage lists. In this proposed topology we are utilizing fluffy rationale controller to Single-Phase To Three-Phase Unified Power Quality Conditioner to decrease of the music and execution will be expanded. Along these lines, a 3P4W framework with fluffy managed, offset and sinusoidal voltages with low consonant substance is accommodated single and three stage loads. An examination of the power move through the arrangement and parallel converters is performed so as to help the structuring of the power converters. Reenactment results are exhibited for approving the proposition of fluffy, just as assessing the static and dynamic exhibitions of the proposed topology.

Effect of inspiratory flow waveforms on the mechanical work of ventilation; a fluid dynamic analysis

In most intensive care patients, the mechanical work (MW) is increased due to airway obstruction and/or tracheal intubation. Increasing MW is known as a risk factor for ventilator induced lung injury (VILI). Moeover, minimizing of MW is crucial to facilitate weaning process. In this paper MW is compared between three different inspiratory flow waveforms. The fluid dynamic analysis is used to compute the resistive pressure drop and the resistive work. We have compared square, sinusoidal and decelerating flow waveforms under the same tidal volume. The results show that under the constant tidal volume and I:E ratio, for tidal volumes below 1 lit, an square flow profile is beneficial for minimizing MW while a sinusoidal flow profile is prefered for tidal volumes of 1 lit or higher. It is shown that for make a decision about most beneficial flow profile in terms of less MW, both tidal volume and I:E ratio is important. By the way the results suggest to use decelerating flow waveforms with higher 1:E ratio. The qualitative conclusion is that in order to lower the MW especially in patients with obstructive lung diseases, sinusoidal, square and decelerating flow became preferable respectively with increasing I:E ratio. Our study suggest the square and sinusoidal profile for tidal volumes below and equal or over 1 lit, respectively in pointwiew of less MW. This paper also encouraged the engineers to add an option to select sinusoidal flow waveform in VCV mode to lower MW when tidal volume is l lit or higher.