Experimental Study of the Deposition of Magnetic Particles on the Walls of Microchannels

This study analyzes experimentally the deposition of magnetic beads on the walls of a square microchannel by the action of a nearby cubical magnet. The deposition has been studied for different magnetic bead sizes, flow rates, magnetic conditions and with solutions of magnetic and non-magnetic particles. Images of the time evolution of the deposition under the different conditions have been analyzed to determine the spatial distribution of the accumulation and the growth rate of the depositions. It has been found that the way in which the magnetic beads are deposited on the walls of the microchannel depends strongly on their size and the magnetic configuration. The accumulation of the major part of particles is on the wall closest to the magnet and, depending on the size of the particles, near the magnet leading and trailing edges or near the center of the magnet. The experiments with magnetic and non-magnetic particles revealed the screening effect of the non-magnetic particles on the deposition. In this case, the non-magnetic particles displace the deposition toward the region near the center of the magnet and near the trailing edge.

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Experimental Study of Particle-Liquid Flow Behaviour in a Microchannel Attached to an Inlet Reservoir

ASME 2008 6th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2008-62365 ◽

2008 ◽

Author(s):

Clement K. M. Kong ◽

Sasan Raghibizadeh ◽

Masahiro Kawaji

Keyword(s):

Experimental Study ◽

Fluid Flow ◽

Liquid Mixture ◽

Average Distance ◽

Liquid Mixtures ◽

Average Density ◽

Flow Rates ◽

Carrier Fluid ◽

Square Microchannel ◽

Cylindrical Reservoir

An experimental study of a solid particle-liquid mixture in a microchannel was conducted by injecting a particle-liquid mixture into a 3.0 mm diameter cylindrical reservoir connected to a square microchannel. Glass particles with diameters ranging from 8 to 12 μm and density between 0.95 and 1.15g/ml, as well as polystyrene particles with diameters ranging from 8 to 50μm and an average density of 1.03–1.05 g/ml were mixed with de-ionized water to create particle-liquid mixtures. The mixture could be continuously stirred in the reservoir using a small magnetic stir bar. The number of particles entering the microchannel was found to depend on the concentration and density of the particles in the reservoir, stirring and fluid flow rates. The particles with a density larger than the carrier fluid entered the microchannel, settled at the bottom of the channel and became immobile at low fluid flow rates, blocking the subsequent particle flow. In many cases, the particles flowed in small groups or clusters, which were separated by short distances. The average distance between the particles or particle clusters was found to vary both with the stirring rate in the reservoir as well as the fluid flow rate in the microchannel.

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Magnetophoresis ‘meets’ viscoelasticity: deterministic separation of magnetic particles in a modular microfluidic device

Lab on a Chip ◽

10.1039/c5lc00106d ◽

2015 ◽

Vol 15 (8) ◽

pp. 1912-1922 ◽

Cited By ~ 38

Author(s):

Francesco Del Giudice ◽

Hojjat Madadi ◽

Massimiliano M. Villone ◽

Gaetano D'Avino ◽

Angela M. Cusano ◽

...

Keyword(s):

Microfluidic Device ◽

Magnetic Particles ◽

Magnetic Beads ◽

Microfluidic Channel

Deflection of magnetic beads in a microfluidic channel can be improved through viscoelastic focusing.

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The Clogging Behavior of a Vortex Pump: An Experimental Study on the Influence of Impeller Designs

Volume 1A, Symposia: Keynotes; Advances in Numerical Modeling for Turbomachinery Flow Optimization; Fluid Machinery; Industrial and Environmental Applications of Fluid Mechanics; Pumping Machinery ◽

10.1115/fedsm2017-69021 ◽

2017 ◽

Author(s):

Angela Gerlach ◽

Dorian Perlitz ◽

Flemming Lykholt-Ustrup ◽

Christian Brix Jacobsen ◽

Paul Uwe Thamsen

Keyword(s):

Experimental Study ◽

Power Consumption ◽

Clear Water ◽

Blade Angle ◽

Flow Rates ◽

Blade Number ◽

Outlet Angle ◽

Vortex Pump ◽

Efficiency Losses ◽

Angle Blade

This paper analyzes the clogging behavior of a vortex pump with different impeller designs. The influence of blade outlet angle, blade number, and impeller diameter were tested. Non-woven textiles in different concentrations served as the clogging material. The results suggest that a smaller outlet blade angle, a higher blade number, and a larger impeller diameter allow pumping more textiles. Impellers that were capable of pumping more textiles, however, were less efficient. Overall, pumping textiles causes efficiency losses. However, this could not be only related to increased power consumption. Flow rates under clogging operation were close to the flow rates under clear water operation irrespective of the amount of clogging material and the impellers design. Further, in all tests clogging material accumulated at the suction mouth in the casing.

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Growth of GaN from elemental Gallium and Ammonia via Modified Sandwich Growth Technique

MRS Proceedings ◽

10.1557/proc-831-e11.38 ◽

2004 ◽

Vol 831 ◽

Cited By ~ 1

Author(s):

E. Berkman ◽

R. Collazo ◽

R. Schlesser ◽

Z. Sitar

Keyword(s):

Growth Rate ◽

Gas Flow ◽

Transport Model ◽

Theoretical Calculations ◽

Substrate Surface ◽

Maximum Growth ◽

Direct Reaction ◽

Pure Nitrogen ◽

Flow Rates ◽

Reactor Pressure

ABSTRACTGallium nitride (GaN) films were grown on (0001) sapphire substrates at 1050°C by controlled evaporation of gallium (Ga) metal and reaction with ammonia (NH3) at a total reactor pressure of 800 Torr. Pure nitrogen (N2) was flowed directly above the molten Ga source to prevented direct reaction between the molten Ga and ammonia, which causes Ga spattering and GaN crust formation. At the same time, this substantially enhanced the Ga transport to the substrate. A simple mass-transport model based on total reactor pressure, gas flow rates and source temperature was developed and verified. The theoretical calculations and growth rate measurements at different ammonia flow rates and reactor pressures showed that the maximum growth rate was controlled by transport of both Ga species and reactive ammonia to the substrate surface.

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Experimental study of solar desalination performance due to water depths, flow rates, and using heat recovery from disposed brine

International Journal of Ambient Energy ◽

10.1080/01430750.2021.1999324 ◽

2021 ◽

pp. 1-24

Author(s):

M. R. Assari ◽

H. Basirat Tabrizi ◽

M. Parvar ◽

E. Esfandeh

Keyword(s):

Experimental Study ◽

Heat Recovery ◽

Flow Rates ◽

Solar Desalination ◽

Water Depths

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Experimental study of slug flow for condensation in a single square microchannel

Experimental Thermal and Fluid Science ◽

10.1016/j.expthermflusci.2011.10.013 ◽

2012 ◽

Vol 38 ◽

pp. 1-13 ◽

Cited By ~ 17

Author(s):

Ahmad Odaymet ◽

Hasna Louahlia-Gualous

Keyword(s):

Experimental Study ◽

Slug Flow ◽

Square Microchannel

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Spatial distribution and hydrochemistry of springs and seepage springs in the Lubuska Upland of western Poland

Hydrology Research ◽

10.2166/nh.2013.249 ◽

2013 ◽

Vol 45 (3) ◽

pp. 379-390 ◽

Cited By ~ 6

Author(s):

Anna Maria Szczucińska

Keyword(s):

Electrical Conductivity ◽

Spatial Distribution ◽

Trace Metals ◽

Calcium Ions ◽

Major Part ◽

Major Ions ◽

Water Type ◽

Average Temperature ◽

Last Glaciation ◽

River Valleys

The major part of the Polish Plain (central Europe) was shaped during the last glaciation and so far has been considered to be poor in groundwater outflows. The present study aimed to map the groundwater outflows and to analyse their water properties in the Lubuska Upland, western Polish Plain. The mapping of the groundwater outflows was supplemented by hydrochemical analyses (major ions and trace metals) of selected outflows. Altogether, approximately 600 groundwater outflows were recorded, of which 45% were springs. The outflow water discharges ranged from 0.001 to 45 L s−1. Most of them were located at the bottom of the slopes of river valleys. The water was neutral (pH 6.9 to 8.11), with electrical conductivity from 261 to 652 μS cm−1 and average temperature ~10 °C. The most common water type was dominated by bicarbonate, sulphates and calcium ions. The waters often exceeded the quality limits for total Fe and Mn2+. This study revealed that groundwater outflows are a common feature of the areas shaped by former glaciations and are most likely supplied by shallow aquifers.

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The Research of a New Method for Manipulating Magnetic Beads through Multi-Layered Flat Micro-Coils Coupled with Permanent Magnet

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.753-755.1571 ◽

2013 ◽

Vol 753-755 ◽

pp. 1571-1575

Author(s):

Zhi Hua Liu ◽

Yu Feng Huang ◽

Jian Peng Li ◽

Xin Wei Xu

Keyword(s):

Magnetic Field ◽

Permanent Magnet ◽

Flow Velocity ◽

Magnetic Beads ◽

Magnetic Bead ◽

New Method ◽

Viscous Resistance ◽

Main Factors ◽

The Magnetic Field

Magnetic bead droplet's non-contacted manipulation can be realized in Electromagnetic MEMS, but how to achieve magnetic beads manipulation is the major problem. A new method of multi-layered flat coils coupled with permanent magnet was proposed. Firstly, the theory of magnetic bead manipulation was analyzed and the main factors affected the magnetic beads manipulation was identified; then the magnetic field of multi-layered flat coils and Stokes viscous resistance of magnetic beads were analyzed and simulated quantificationally; finally the magnetic bead capture area was got under different flow velocity. Consequently the feasibility and correctness of this method was verified.

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The Magnetic Bead Computing Model of the 0-1 Integer Programming Problem Based on DNA Cycle Hybridization

Mathematical Problems in Engineering ◽

10.1155/2021/6692294 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Rujie Xu ◽

Zhixiang Yin ◽

Zhen Tang ◽

Jing Yang ◽

Jianzhong Cui ◽

...

Keyword(s):

Integer Programming ◽

Programming Problem ◽

Magnetic Beads ◽

Specific Binding ◽

Optimal Solution ◽

High Sensitivity ◽

Magnetic Bead ◽

Integer Programming Problem ◽

Computing Model ◽

Dna Strands

Magnetic beads and magnetic Raman technology substrates have good magnetic response ability and surface-enhanced Raman technology (SERS) activity. Therefore, magnetic beads exhibit high sensitivity in SERS detection. In this paper, DNA cycle hybridization and magnetic bead models are combined to solve 0-1 integer programming problems. First, the model maps the variables to DNA strands with hairpin structures and weights them by the number of hairpin DNA strands. This result can be displayed by the specific binding of streptavidin and biotin. Second, the constraint condition of the 0-1 integer programming problem can be accomplished by detecting the signal intensity of the biological barcode to find the optimal solution. Finally, this model can be used to solve the general 0-1 integer programming problem and has more extensive applications than the previous DNA computing model.

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