scholarly journals High-Throughput Particle Concentration Using Complex Cross-Section Microchannels

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 440 ◽  
Author(s):  
Asma Mihandoust ◽  
Sajad Razavi Bazaz ◽  
Nahid Maleki-Jirsaraei ◽  
Majid Alizadeh ◽  
Robert A. Taylor ◽  
...  

High throughput particle/cell concentration is crucial for a wide variety of biomedical, clinical, and environmental applications. In this work, we have proposed a passive spiral microfluidic concentrator with a complex cross-sectional shape, i.e., a combination of rectangle and trapezoid, for high separation efficiency and a confinement ratio less than 0.07. Particle focusing in our microfluidic system was observed in a single, tight focusing line, in which higher particle concentration is possible, as compared with simple rectangular or trapezoidal cross-sections with similar flow area. The sharper focusing stems from the confinement of Dean vortices in the trapezoidal region of the complex cross-section. To quantify this effect, we introduce a new parameter, complex focusing number or CFN, which is indicative of the enhancement of inertial focusing of particles in these channels. Three spiral microchannels with various widths of 400 µm, 500 µm, and 600 µm, with the corresponding CFNs of 4.3, 4.5, and 6, respectively, were used. The device with the total width of 600 µm was shown to have a separation efficiency of ~98%, and by recirculating, the output concentration of the sample was 500 times higher than the initial input. Finally, the investigation of results showed that the magnitude of CFN relies entirely on the microchannel geometry, and it is independent of the overall width of the channel cross-section. We envision that this concept of particle focusing through complex cross-sections will prove useful in paving the way towards more efficient inertial microfluidic devices.

Author(s):  
Frank Altmann ◽  
Jens Beyersdorfer ◽  
Jan Schischka ◽  
Michael Krause ◽  
German Franz ◽  
...  

Abstract In this paper the new Vion™ Plasma-FIB system, developed by FEI, is evaluated for cross sectioning of Cu filled Through Silicon Via (TSV) interconnects. The aim of the study presented in this paper is to evaluate and optimise different Plasma-FIB (P-FIB) milling strategies in terms of performance and cross section surface quality. The sufficient preservation of microstructures within cross sections is crucial for subsequent Electron Backscatter Diffraction (EBSD) grain structure analyses and a high resolution interface characterisation by TEM.


2020 ◽  
Vol 10 (8) ◽  
pp. 2642 ◽  
Author(s):  
Łukasz Drobiec ◽  
Rafał Wyczółkowski ◽  
Artur Kisiołek

The article describes the results of numerical analyses and traditional calculations of the heat transfer coefficient in ceilings with a complex cross-section, and with materials of varying density built-in inside the cross-section. Prefabricated prestressed reinforced concrete, composite reinforced, and ribbed reinforced concrete ceilings were analyzed. Traditional calculations were carried out in accordance with the EN ISO 6946:2017 standard, while the numerical analyses were carried out in a program based on the finite element method (FEM). It has been shown that calculations can be a good alternative to nondestructive testing (NDT) and laboratory tests, whose use in the case of ceilings with different geometries is limited. The differences between the calculations carried out in accordance with EN ISO 6946:2017, and the results of numerical analyses are 12%–39%. The way the air voids are taken into account has an impact on the calculation results. In the traditional method, an equivalent thermal conductivity coefficient was used, while in the numerical analysis, the coefficient was selected from the program’s material database. Since traditional calculations require simplifications, numerical methods should be considered to give more accurate results.


Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3304
Author(s):  
Hyon Wook Ji ◽  
Jeong-Hee Kang ◽  
Dan Daehyun Koo ◽  
Sung Soo Yoo

A complex cross-section reinforced concrete pipe that combines a sub-pipe for the flow of sewage in dry weather and a main pipe for the flow of rainwater was developed to reduce sedimentation of the combined sewer system in dry weather. The sub-pipe was designed, considering the flow velocity, constructability, and maintenance. By fitting the sewage data in the dry weather to the normal distribution, the ratio of the cross-sectional area of sewage flow to that of the pipe was determined to be approximately 0.418, which could cover 99.85% of the sewage volume of the target site. Based on this ratio, the diameter of the sub-pipe corresponding to the combined sewer system with a pipe diameter between 450 and 1300 mm was determined. The hydraulic performance analysis results showed that the flow velocity increased by 11 to 12% compared to the circular pipe based on the full sub-pipe and by more than 15% depending on the water level. The shear stress increased by more than 16.5%, and higher tractive force was observed. Structural safety was determined as the crack load and failure load far exceeded the minimum criteria, thereby verifying the feasibility and field applicability of the complex cross-section reinforced concrete pipe.


2019 ◽  
Vol 28 (12) ◽  
pp. 1950105 ◽  
Author(s):  
Pooja Kaushal ◽  
Manoj K. Sharma

The decay analysis of [Formula: see text]Po[Formula: see text] compound nucleus (CN), formed via [Formula: see text]Ca+[Formula: see text]Gd reaction, with inclusion of additional degrees-of-freedom, i.e., the higher multipole deformations, the octupole ([Formula: see text]) and hexadecupole ([Formula: see text]), the corresponding “compact” orientations ([Formula: see text]), and noncoplanarity degree-of-freedom ([Formula: see text]0), is investigated within the collective clusterization approach. The Quantum Mechanical Fragmentation Theory (QMFT)-based Dynamical Cluster-decay Model (DCM), wherein the point of penetration [Formula: see text], fixed via the in-built neck-length parameter [Formula: see text] in [Formula: see text] (equivalently, the “barrier lowering” [Formula: see text]), is used to best fit the channel cross-section ([Formula: see text]) and predict the quasi-fission (qf)-like nCN cross-section [Formula: see text], if any, and the fusion–fission ([Formula: see text]) cross-sections. We also look for other target-projectile (t-p) combinations for the synthesis of CN [Formula: see text]Po[Formula: see text].


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3291
Author(s):  
Hyon Wook Ji ◽  
Sung Soo Yoo ◽  
Dan Daehyun Koo ◽  
Jeong-Hee Kang

The difference in the amount of stormwater and sewage in a combined sewer system is significantly large in areas where heavy rainfall is concentrated. This leads to a low water level and slow flow velocity inside the pipes, which causes sedimentation and odor on non-rainy days. A complex cross-section module increases the flow velocity by creating a small waterway inside the pipe for sewage to flow on non-rainy days. While considering Manning’s equation, we applied the principle where the flow velocity is proportional to two-thirds of the power of the hydraulic radius. The flow velocity of a circular pipe with a diameter of 450 mm and the corresponding complex cross-section module was analyzed by applying Manning’s equation and numerical modeling to show the effects of the complex cross-section module. The tractive force was compared based on a lab-scale experiment. When all conditions were identical except for the cross-sectional shape, the average flow velocity of the complex cross-section module was 14% higher while the size of the transported sand grains was up to 0.5 mm larger. This increase in flow velocity can be even higher if the roughness coefficient of aging pipes can be decreased.


2012 ◽  
Vol 174-177 ◽  
pp. 102-108 ◽  
Author(s):  
Guang Hong Feng ◽  
Hong Liang Zhang ◽  
Pei Zhang ◽  
Xu Chang Zhou ◽  
Yong Zhao

Through analyzing the molding process characteristics of cold-formed steel sheet piling, mechanical testing and metallographic analysis was made on the curved position of the U-shaped cold-formed steel sheet piling , the following conclusions was drawn: Cold formed steel sheet pile was subjected to the complex cross-section cold roll forming process, resulting in the uneven performance of a steel sheet piling along the horizontal. For the open cold formed steel of asymmetric steel sheet piling and complex cross section, a simple test at flat panel location is difficult to represent the overall performance of cold-formed steel, therefore it is necessary to make a comprehensive performance test on locking. A test method to check the locking occlusion performance on the cold bending steel plate is put forward. The experimental tensile strength of the Q235 level of ordinary carbon steel production of cold-formed steel sheet piling locking bite is 66MPa.


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