Replication Quality of Flow-Through Microfilters in Microfluidic Lab-on-a-Chip for Blood Typing by Microinjection Molding

Author(s):  
Bong-Kee Lee ◽  
Chul Jin Hwang ◽  
Dong Sung Kim ◽  
Tai Hun Kwon

In the present study, replication of flow-through microfilters in the newly developed microfluidic lab-on-a-chip for blood typing by microinjection molding process was experimentally investigated. As a precise replication of the microfilters was required in order to effectively filter out agglutinated red blood cells, the effects of important processing conditions on the replication of the flow-through microfilters were investigated. By using a mold insert fabricated by a nickel electroplating process and a newly designed mold base, microinjection molding experiments were carried out. A three-dimensional solid model reconstruction method was proposed with the help of specific features characterizing the geometry of microfilters, and accordingly, the feature values of the replicated microfilters were measured by a noncontact optical measurement system. So reconstructed solid modeling result was then used to investigate the effects of various processing conditions, such as a flow rate, a mold temperature, and a packing pressure. Amongst the processing conditions investigated in the present study, the flow rate was found to be the most important one.

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.


2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.


2018 ◽  
Vol 8 (8) ◽  
pp. 1309 ◽  
Author(s):  
Andrzej Polanczyk ◽  
Aleksandra Piechota-Polanczyk ◽  
Christoph Domenig ◽  
Josif Nanobachvili ◽  
Ihor Huk ◽  
...  

Background: We aimed to verify the accuracy of the Computational Fluid Dynamics (CFD) algorithm for blood flow reconstruction for type IIIb aortic dissection (TBAD) before and after thoracic endovascular aortic repair (TEVAR). Methods: We made 3D models of the aorta and its branches using pre- and post-operative CT data from five patients treated for TBAD. The CFD technique was used to quantify the displacement forces acting on the aortic wall in the areas of endograft, mass flow rate/velocity and wall shear stress (WSS). Calculated results were verified with ultrasonography (USG-Doppler) data. Results: CFD results indicated that the TEVAR procedure caused a 7-fold improvement in overall blood flow through the aorta (p = 0.0001), which is in line with USG-Doppler data. A comparison of CFD results and USG-Doppler data indicated no significant change in blood flow through the analysed arteries. CFD also showed a significant increase in flow rate for thoracic trunk and renal arteries, which was in accordance with USG-Doppler data (accuracy 90% and 99.9%). Moreover, we observed a significant decrease in WSS values within the whole aorta after TEVAR compared to pre-TEVAR (1.34 ± 0.20 Pa vs. 3.80 ± 0.59 Pa, respectively, p = 0.0001). This decrease was shown by a significant reduction in WSS and WSS contours in the thoracic aorta (from 3.10 ± 0.27 Pa to 1.34 ± 0.11Pa, p = 0.043) and renal arteries (from 4.40 ± 0.25 Pa to 1.50 ± 0.22 Pa p = 0.043). Conclusions: Post-operative remodelling of the aorta after TEVAR for TBAD improved hemodynamic patterns reflected by flow, velocity and WSS with an accuracy of 99%.


1999 ◽  
Author(s):  
Alan M. Tom ◽  
Akihisa Kikuchi ◽  
John P. Coulter

Abstract The current investigation focused on contributing to the development of a novel injection molding process by attempting to understand the scientific relationship that exist between the applied vibrational parameters involved in this process and the effect it has on final product polymeric characterization. Although previous and current attempts at understanding the connection between applied oscillatory or vibrational motion to an injection molding process has shown positive quantitative advantages to final product properties, there still exists a void in the scientific explanation on a molecular level linking these effects. This experimental study, in particular, involved an evaluation on a range of processing conditions applied to Polystyrene and the effects it produced on resultant product quality and polymer properties. Optimal control and mechanical vibrational molding conditions were obtained for Polystyrene. As a result of this, optimal opportunities for initial commercial utilization of the technology can be proposed.


2021 ◽  
Author(s):  
Ekhwaiter Abobaker ◽  
Abadelhalim Elsanoose ◽  
Mohammad Azizur Rahman ◽  
Faisal Khan ◽  
Amer Aborig ◽  
...  

Abstract Perforation is the final stage in well completion that helps to connect reservoir formations to wellbores during hydrocarbon production. The drilling perforation technique maximizes the reservoir productivity index by minimizing damage. This can be best accomplished by attaining a better understanding of fluid flows that occur in the near-wellbore region during oil and gas operations. The present work aims to enhance oil recovery by modelling a two-phase flow through the near-wellbore region, thereby expanding industry knowledge about well performance. An experimental procedure was conducted to investigate the behavior of two-phase flow through a cylindrical perforation tunnel. Statistical analysis was coupled with numerical simulation to expand the investigation of fluid flow in the near-wellbore region that cannot be obtained experimentally. The statistical analysis investigated the effect of several parameters, including the liquid and gas flow rate, liquid viscosity, permeability, and porosity, on the injection build-up pressure and the time needed to reach a steady-state flow condition. Design-Expert® Design of Experiments (DoE) software was used to determine the numerical simulation runs using the ANOVA analysis with a Box-Behnken Design (BBD) model and ANSYS-FLUENT was used to analyses the numerical simulation of the porous media tunnel by applying the volume of fluid method (VOF). The experimental data were validated to the numerical results, and the comparison of results was in good agreement. The numerical and statistical analysis demonstrated each investigated parameter’s effect. The permeability, flow rate, and viscosity of the liquid significantly affect the injection pressure build-up profile, and porosity and gas flow rate substantially affect the time required to attain steady-state conditions. In addition, two correlations obtained from the statistical analysis can be used to predict the injection build-up pressure and the required time to reach steady state for different scenarios. This work will contribute to the clarification and understanding of the behavior of multiphase flow in the near-wellbore region.


Abstract.—Aquatic Filter Barrier (AFB) is a permeable fabric material used to reduce the entrainment of ichthyoplankton at water intakes. To determine the potential for this material to protect a wide range of species, we evaluated the retention and survival of the early life stages of common carp <em>Cyprinus carpio</em>, rainbow smelt <em>Osmerus mordax</em>, white sucker <em>Catostomus commersonii</em>, striped bass <em>Morone saxatilis</em>, and bluegill <em>Lepomis macrochirus </em>exposed to AFB fabric in the laboratory. Twelve flow-through testing apparatuses were used in a closed-loop system to evaluate two flow rates (0.04 L/min/cm2) and 0.08 L/min/cm2) and three sizes of fabric perforation (0.5, 1.0, and 1.5 mm) with each species. The results indicate that, with one exception (pair-wise comparison of bluegill survival between 1.0-mm and 1.5- mm perforations; <em>p </em>= 0.0481), survival of organisms was not significantly correlated (<em>p </em>≤ 0.05) to either flow rate or perforation size. Retention of organisms decreased significantly with increasing flow rate for one species of fish (pair-wise comparison of rainbow smelt between 0.04 and 0.08 L/min/cm<sup>2</sup>; <em>p </em>= 0.0084). In addition, larger perforation sizes resulted in significant decreases in retention for three of the test species (common carp, rainbow smelt, and striped bass; <em>p </em>≤ 0.05). Consequently, the potential effectiveness AFB material is reduced by the use of larger perforation sizes. Provided that the material can be maintained and perforation sizes remain small (0.5 mm), AFB should prevent the entrainment of the majority of the organisms of the species tested in the laboratory.


2019 ◽  
Vol 35 (5) ◽  
pp. 745-749
Author(s):  
L. E. Christianson ◽  
R. D. Christianson ◽  
A. E. Lipka ◽  
S. Bailey ◽  
J. Chandrasoma ◽  
...  

Abstract. Dependable flow rate measurements are necessary to calculate flow volumes and resulting nutrient loads from subsurface drainage systems and associated conservation practices. The objectives of this study were (1) to develop appropriate weir equations for a new stainless steel-edged 45° V-notch weir developed for AgriDrain inline water level control structures and (2) to determine if the equation was independent of flow depth in the structure. Weirs for 15 cm (6 in.) and 25 cm (10 in.) inline water level control structures were placed at three heights in each structure: at the base, 48 cm from the base, or 97 cm from the base, and the height of the nappe above the weir crest was recorded over a range of flow rates. The resulting data were fitted to equations of the form Q = aHb where Q is the flow rate, H is the height of the nappe above the weir crest, and a and b are fitted parameters. There were no significant differences in the fitted parameters across the two structure sizes or across the three weir placements. The fitted equation for these new stainless steel-edged V-notch weirs was Q = 0.011H2.28 with Q in liters per second and H in centimeters, and Q = 1.44H2.28, with Q in gallons per minute and H in inches. These equations can be used for measuring flow through AgriDrain in-line structures, although in-house weir calibration is highly recommended for specific applications, when possible. Keywords: Drainage, Flow monitoring, Subsurface drainage, V-notch weir, Weir calibration.


1981 ◽  
Vol 54 (4) ◽  
pp. 556-558 ◽  
Author(s):  
Sherman C. Stein ◽  
Stewart Apfel

✓ A method of measuring flow rate through cerebrospinal fluid (CSF) shunts is reported. It consists of two thermistors in series applied to the skin over the shunt tubing. The thermistors respond by a drop in measured temperature following application of an ice cube placed on the skin overlying the proximal shunt tube. The time required for the thermal response to travel between the two thermistors is related to the velocity of flow through the shunt tubing. Flow rate can then be calculated using the internal diameter of the tubing. A series of animal experiments employing a constant infusion of mock CSF through subcutaneously implanted shunt tubing showed excellent correlation between calculated flow rates and actual infusion rates. The device is noninvasive and easily adapted to use in patients. The measurements are readily repeatable.


Author(s):  
Alicia B. Rodríguez ◽  
Esmeralda Niño ◽  
Jose M. Castro ◽  
Marcelo Suarez ◽  
Mauricio Cabrera

In this work, two criteria in conflict are considered simultaneously to determine a process window for injection molding. The best compromises between the two criteria are identified through the application of multiple criteria optimization concepts. The aim with this work is to provide a formal and realistic strategy to set processing conditions in injection molding operations. In order to keep the main ideas manageable, the development of the strategy is constrained to two controllable variables in computer simulated parts.


Sign in / Sign up

Export Citation Format

Share Document