scholarly journals Analysis of the Binding of Analyte-Receptor in a Micro-Fluidic Channel for a Biosensor Based on Brownian Motion

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 570
Author(s):  
Sunghak Choi ◽  
Woo Il Lee ◽  
Gyu Hee Lee ◽  
Yeong-Eun Yoo
Keyword(s):  
Mathematical Model ◽  
Brownian Motion ◽  
Flow Rate ◽  
Channel Height ◽  
Micro Channel ◽  
Analyte Concentration ◽  
Fluidic Channel ◽  
Binding Characteristics ◽  
Detection Characteristics ◽  
The Mathematical Model

This study experimentally analyses the binding characteristics of analytes mixed in liquid samples flowing along a micro-channel to the receptor fixed on the wall of the micro-channel to provide design tools and data for a microfluidic-based biosensor. The binding or detection characteristics are analyzed experimentally by counting the number of analytes bound to the receptor, with sample analyte concentration, sample flow rate, and the position of the receptor along the micro-channel length as the main variables. A mathematical model is also proposed to predict the number of analytes transported and bound to the receptor based on a probability density function for Brownian motion. The coefficient in the mathematical model is obtained by using a dimensionless mathematical model and the experimental results. The coefficient remains valid for all different conditions of the sample analyte concentration, flow rate, and the position of the receptor, which implies the possibility of deriving a generalized model. Based on the mathematical model derived from mathematical and experimental analysis on the detection characteristics of the microfluidic-based biosensor depending on previously mentioned variables and the height of the micro-channel, this study suggests a design for a microfluidic-based biosensor by predicting the binding efficiency according to the channel height. The results show the binding efficiency increases as the flow rate decreases and as the receptor is placed closer to the sample-injecting inlet, but is unaffected by sample concentration.

Low-cost flow-rate estimate in separate layers along gas wells from temperature and pressure profiles

2013 ◽  
Vol 53 (1) ◽  
pp. 285
Author(s):  
Emile Barrett ◽  
Imran Abbasy ◽  
Chii-Rong Wu ◽  
Zhenjiang You ◽  
Pavel Bedrikovetsky
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Flow Rate ◽  
Low Cost ◽  
Pressure Sensors ◽  
Gas Wells ◽  
Production Rates ◽  
Pressure Profiles ◽  
Temperature And Pressure ◽  
The Mathematical Model

Estimation of rate profile along the well is important information for reservoir characterisation since it allows distinction of the production rates from different layers. The temperature and pressure sensors in a well are small and inexpensive; while flow meters are cumbersome and expensive, and affect the flow in the well. The method presented in this peer-reviewed paper shows its significance in predicting the gas rate from temperature and pressure data. A mathematical model for pressure and temperature distributions along a gas well has been developed. Temperature and pressure profiles from nine well intervals in field A (Cooper Basin, Australia) have been matched with the mathematical model to determine the flow rates from different layers in the well. The presented model considers the variables as functions of thermal properties at each location, which is more accurate and robust than previous methods. The results of tuning the mathematical model to the field data show good agreement with the model prediction. Simple and robust explicit formulae are derived for the effective estimation of flow rate and thermal conductivity in gas wells. The proposed approach has been applied to determine the well gas rate and formation thermal conductivity from the acquired well pressure and temperature data in field A. It allows for recommending well stimulation of layers with low production rates.

Bubble Removal in Microfluidic Devices Using Nanofibrous Membranes

2014 ◽  
Author(s):  
Ravindra Vundavilli ◽  
Jeff Darabi
Keyword(s):  
Pore Size ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Microfluidic Devices ◽  
Channel Height ◽  
Hydrophobic Membrane ◽  
Fluidic Channel ◽  
Nanofibrous Membranes ◽  
Bubble Removal

This paper presents an experimental study to determine bubble removal characteristics of nanofibrous membranes in microfluidic devices. It is well known that the presence of gas bubbles in fluidic channels can cause significant flow disturbances and adversely affect the overall performance and operation of microfluidic devices. In this study, a microfluidic device is designed and fabricated to generate and extract bubbles from a microfluidic channel. A T-junction is used to produce controllable bubbles at the entrance of fluidic channel. The generated bubbles are then transported to a bubble removal region and vented through a highly porous hydrophobic membrane. Four different hydrophobic PTFE membranes with different pore sizes ranging from 0.45 to 3 μm were used to permeate air bubbles. The fluidic channel width was 500 μm and channel height ranged from 100 to 300 μm. The effects of pore size, channel height, and liquid flow rate on the bubble removal rate are investigated. The results reveal that the rate of bubble removal increases with increasing the pore size and channel height but decreases with increasing the liquid flow rate.

scholarly journals Mathematical model of a steam turbine condenser

2021 ◽  
Vol 80 (2) ◽  
pp. 41-46
Author(s):  
N. G. Borissova ◽  
◽  
M. D. Shavdinova ◽  
Keyword(s):  
Mathematical Model ◽  
Vapor Pressure ◽  
Steam Turbine ◽  
Flow Rate ◽  
Cooling Water ◽  
Calculation Methods ◽  
Turbine Condenser ◽  
Passport Data ◽  
Steam Turbine Condenser ◽  
The Mathematical Model

The paper analyses the existing calculation methods for steam turbine condenser. The refined methods for calculating the condenser have also been considered. The dependency of the vapor pressure in the condenser on the temperature of the cooling water and the steam flow rate into the condenser have been considered. It can be seen from the obtained dependencies that the calculation of the condenser according to the ARTI and HEI (USA) methods coincides with the passport data. It is recommended to use the ARTI and HEI (USA) techniques for equipment diagnostics, and to use the KTP and USTU-UPI techniques when studying ways to increase the efficiency of the condenser. The mathematical model of the KG2-6200 condenser has been tested at the Almaty СHPP-2.

scholarly journals Nozzle-Shaped Electrode Configuration for Dielectrophoretic 3D-Focusing of Microparticles

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 585 ◽  
Author(s):  
Krishna ◽  
Alnaimat ◽  
Mathew
Keyword(s):  
Mathematical Model ◽  
Microfluidic Device ◽  
Flow Rate ◽  
Electric Potential ◽  
Performance Metrics ◽  
Volumetric Flow Rate ◽  
Electrode Configuration ◽  
Electrode Length ◽  
The Mathematical Model ◽  
Applied Electric Potential

: An experimentally validated mathematical model of a microfluidic device with nozzle-shaped electrode configuration for realizing dielectrophoresis based 3D-focusing is presented in the article. Two right-triangle shaped electrodes on the top and bottom surfaces make up the nozzle-shaped electrode configuration. The mathematical model consists of equations describing the motion of microparticles as well as profiles of electric potential, electric field, and fluid flow inside the microchannel. The influence of forces associated with inertia, gravity, drag, virtual mass, dielectrophoresis, and buoyancy are taken into account in the model. The performance of the microfluidic device is quantified in terms of horizontal and vertical focusing parameters. The influence of operating parameters, such as applied electric potential and volumetric flow rate, as well as geometric parameters, such as electrode dimensions and microchannel dimensions, are analyzed using the model. The performance of the microfluidic device enhances with an increase in applied electric potential and reduction in volumetric flow rate. Additionally, the performance of the microfluidic device improves with reduction in microchannel height and increase in microparticle radius while degrading with increase in reduction in electrode length and width. The model is of great benefit as it allows for generating working designs of the proposed microfluidic device with the desired performance metrics.

Sea Water Pump Station Basin Mathematical Hydraulic Model Test (CFD Analysis)

2009 ◽  
Author(s):  
Sadegh Barzegar ◽  
Alireza Elhami Amiri ◽  
Pooyan Rahbar ◽  
Mehdi Assadi Niazi
Keyword(s):  
Mathematical Model ◽  
Free Surface ◽  
Model Test ◽  
Flow Rate ◽  
Sea Water ◽  
Water Pump ◽  
Pumping Station ◽  
Water Pumping ◽  
Pump Station ◽  
The Mathematical Model

Background and aim: A sea water intake, with original design of the six drum screen and twenty sea water pump intake with very different flow rate connected to header bay. The capacity of Origin Sea water intake including huge pump station and drum screen is 200,000 m3/hr. The purpose of the mathematical hydraulic model test of the sea water pumping station is to verify that the basin allows a good operating condition for each pump. To ensure a good operating condition for each pump, the design of the seawater basin has to insure: • A correct filter working; • Low transversal velocities; • A flow without vortex. Method and material: The mathematical model of the basin allows to know the flow and to verify: • The main dimensions of the pumping station; • The distance between the inlet ducts and the filters; • The distance between the filters and pump chambers. Result: in the first basin, the flow patterns no problems. Only swirl at the exit of culverts and near the free surface, and two areas where the flow has no velocity were observed. In the downstream other filters, we observe also a circulation that generates a tangential velocity. Conclusion: The mathematical model of the sea water pumping station has allowed calculating three cases (without and with filter stopped) for the low water level and nominal flow rate. In most difficult case, we observe some recirculation, mainly near the free surface, without more influence on principal flow. In the three cases, the distribution of the flow rate between the drum screens is uniform; the gap is inferior to 2%. At the entry of the pump chambers, the velocity fluctuations and the angle are low. Consequently, the secondary flows in pump chambers will be limited.

Experimental and Theoretic Research on Solar Power Membrane Distillation

2010 ◽  
Vol 97-101 ◽  
pp. 2300-2305
Author(s):  
Hong Jiang Cui ◽  
Pei Ting Sun ◽  
Ming Hai Li
Keyword(s):  
Mathematical Model ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Solar Power ◽  
Membrane Distillation ◽  
Working Fluid ◽  
Air Gap Membrane Distillation ◽  
The Mathematical Model

Air gap membrane distillation experiments of different temperature and mass flow rate of working fluid were done for the use of solar power and setting up the mathematical model of AGMD’ heat and mass transfer. The calculation correctness of mathematical model was discussed and the thermal efficiency of membrane distillation system was calculated. The results showed that the experimental flux of membrane distillation reached 49kg/m2•h and the biggest relative error is less than 9% between results of experiment and mathematical model calculation. The mathematical model can be used to forecast the process parameters of membrane distillation. The highest thermal efficiency of this system is 68% and the main influencing factors of thermal efficiency are temperature and mass flow rate of working fluid.

Concentration of Samples in Microfluidic Structure Using Joule Heating Effects

2009 ◽  
Author(s):  
Zhengwei Ge ◽  
Chun Yang
Keyword(s):  
Mathematical Model ◽  
Joule Heating ◽  
Electroosmotic Flow ◽  
Scaling Analysis ◽  
Analyte Concentration ◽  
Governing Equations ◽  
Sample Concentration ◽  
Heating Effects ◽  
Concentration Enhancement ◽  
The Mathematical Model

Microfluidic concentration is achieved using temperature gradient focusing (TGF) in a microchannel with a step change in cross-section. A mathematical model is developed to describe the complex TGF processes. The proposed mathematical model includes a set of governing equations for the applied electric potential, electroosmotic flow field, Joule heating induced temperature field, and sample analyte concentration distributions as well. Scaling analysis was conducted to estimate time scales so as to simplify the mathematical model. Numerical computations were performed to obtain the temperature, velocity and sample concentration distributions. Experiments were carried out to study the effects of applied voltage, buffer concentration, and channel size on sample concentration in the TGF processes. These effects were analyzed and summarized using a dimensionless Joule number that was introduced in this study. In addition, Joule number effect in the PDMS/PDMS microdevice was compared with the PDMS/Glass microdevice. A more than 450-fold concentration enhancement was obtained within 75 seconds in the PDMS/PDMS microdevice. Overall, the numerical simulations were found in a reasonable agreement with the experimental results.

The Design and Analyses of Magnetorheological Fluid Throttle Valve

2011 ◽  
Vol 383-390 ◽  
pp. 1208-1214
Author(s):  
Rong Wu ◽  
Wen Xiang Lin ◽  
Wen Tang
Keyword(s):  
Mathematical Model ◽  
Computational Model ◽  
Flow Rate ◽  
Electromagnetic Induction ◽  
Fluid Model ◽  
Scientific Research ◽  
Magnetorheological Fluid ◽  
Research Field ◽  
Throttle Valve ◽  
The Mathematical Model

Magnetorheological (MR) Fluid is an intellectual material with comprehensive prospect. In recent years, it is widely attended in the scientific-research field. Flow rate computational model of the MR throttle valve is derived by using Binham fluid model. The mathematical model of electromagnetic induction intensity for the MR throttle valve is established. The designed magnetorheological throttle valve is simple, compact and has some creativity. Proposed use of magnetorheological hydraulic components presents a problem.

Filtration of anomalous thermoviscous liquid in layered non-uniform formation

2006 ◽  
Vol 4 ◽  
pp. 251-257
Author(s):  
S.F. Khizbullina
Keyword(s):  
Mathematical Model ◽  
Porous Medium ◽  
Flow Rate ◽  
Pressure Difference ◽  
Viscosity Coefficient ◽  
Filtration Flow ◽  
Nonmonotonic Dependence ◽  
Flow Features ◽  
Numerical Research ◽  
The Mathematical Model

The mathematical model is developed and the numerical research of a filtration flow features of liquid with model nonmonotonic dependence of viscosity on temperature is conducted. Existence of the ”viscous barrier“ defining character of a filtration flow of anomalous thermoviscous liquid in the porous medium is established. Characteristic pictures of the steady distribution of viscosity and temperature in layered non-uniform formation are constructed. It is established that formation flow rate depends on a maximum of viscosity coefficient and pressure difference essentially.

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