scholarly journals 3D Hydrodynamic Focusing in Microscale Optofluidic Channels Formed with a Single Sacrificial Layer

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 349 ◽  
Author(s):  
Erik S. Hamilton ◽  
Vahid Ganjalizadeh ◽  
Joel G. Wright ◽  
Holger Schmidt ◽  
Aaron R. Hawkins
Keyword(s):  
Cross Sections ◽  
Optical Waveguides ◽  
Sacrificial Layer ◽  
Three Dimensional ◽  
Single Layer ◽  
Detection Sensitivity ◽  
Low Flow ◽  
Hydrodynamic Focusing ◽  
Induced Focusing ◽  
Pressure Driven Flow

Optofluidic devices are capable of detecting single molecules, but greater sensitivity and specificity is desired through hydrodynamic focusing (HDF). Three-dimensional (3D) hydrodynamic focusing was implemented in 10-μm scale microchannel cross-sections made with a single sacrificial layer. HDF is achieved using buffer fluid to sheath the sample fluid, requiring four fluid ports to operate by pressure driven flow. A low-pressure chamber, or pit, formed by etching into a substrate, enables volumetric flow ratio-induced focusing at a low flow velocity. The single layer design simplifies surface micromachining and improves device yield by 1.56 times over previous work. The focusing design was integrated with optical waveguides and used in order to analyze fluorescent signals from beads in fluid flow. The implementation of the focusing scheme was found to narrow the distribution of bead velocity and fluorescent signal, giving rise to 33% more consistent signal. Reservoir effects were observed at low operational vacuum pressures and a balance between optofluidic signal variance and intensity was achieved. The implementation of the design in optofluidic sensors will enable higher detection sensitivity and sample specificity.

Analysis of beams with piezo-patches by node-dependent kinematic finite element method models

2017 ◽  
Vol 29 (7) ◽  
pp. 1379-1393 ◽  
Author(s):  
Erasmo Carrera ◽  
Enrico Zappino ◽  
Guohong Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Sections ◽  
Constitutive Relations ◽  
Three Dimensional ◽  
Single Layer ◽  
Present Contribution ◽  
Stiffness Matrices ◽  
Carrera Unified Formulation ◽  
Element Method

This article presents a family of one-dimensional finite element method models with node-dependent kinematics for the analysis of beam structures with piezo-patches. The models proposed are built by applying Carrera unified formulation. Carrera unified formulation permits to obtain finite element method stiffness matrices through so-called fundamental nuclei whose form is independent of the assumptions made for the displacement/electrical field over the cross section of a beam. In the previous works, uniform kinematic assumptions have been applied to all the nodes within the same element. The present contribution proposes to use different kinematics on different nodes, leading to node-dependent kinematic finite element method formulations. In such an approach, non-uniform cross sections introduced by piezo-patches can be considered. With the help of layer-wise models, piezoelectric and mechanical domains each can possess individual constitutive relations. Meanwhile, node-dependent kinematics can integrate equivalent single layer models and layer-wise models to reach an optimal balance between accuracy and use of computational resources. Static governing equations for beam elements with node-dependent kinematics accounting for electromechanical effects are derived from the principle of virtual displacements. The competence of the proposed approach is validated by comparing the obtained results with solutions taken from the literature and ABAQUS three-dimensional modelling. Both extension and shear actuation mechanisms are considered.

scholarly journals Accuracy of 2D modeling approach for performance simulation of noncircular single- and dual-layer monolithic catalysts

2021 ◽  
Author(s):  
Behnam Mozaffari
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Single Layer ◽  
Flow Region ◽  
3D Models ◽  
Catalytic Performance ◽  
Cross Sectional ◽  
2D Modeling ◽  
Modeling Approach ◽  
Monolithic Catalysts

This study aims to evaluate the accuracy of widely applied approach of modeling noncircular channels and washcoats of monolithic catalysts with equivalent circular geometrical shapes. For this purpose, catalytic performance of equivalent circular and square channel cross-sectional shapes with single-layer Pt/Al2O3 and dual-layer Fe-ZSM-5+Pt/Al2O3 washcoats are investigated. For the noncircular cross-sections, three-dimensional computational fluid dynamics models that consider species gases convection inside the channel bulk flow region, and reaction and diffusion of species inside the washcoat layer(s) are utilized to simulate the performance of one channel of the monolithic catalytic converters. In addition, in order to investigate the amount of inaccuracy of 2D modeling approach for noncircular channels, 2D models are applied to simulate the equivalent monolithic catalysts with circular cross-sections, and the results of the 2D and 3D models are compared together, and also, with the experimental and 1D+1D modeling technique results available in the literature.

Implications of pericline geometries on 3D fold shape analysis, stress distribution and fracture analysis

2021 ◽  
Author(s):  
Andreas Eckert ◽  
Xiaolong Liu ◽  
Avery Welker ◽  
Peter Connolly ◽  
John Hogan ◽  
...  
Keyword(s):  
Shape Analysis ◽  
Cross Sections ◽  
Three Dimensional ◽  
Single Layer ◽  
Fracture Analysis ◽  
Cross Sectional ◽  
3D Geometry ◽  
Deformation Event ◽  
Dip Isogons ◽  
Distribution Of Stress

<p>The characterization of folds is often limited to two-dimensional cross-sectional views where folds are approximated as cylindrical. This enables simplification of fold shape analysis (using principles such as dip isogons, stereographs, tangent diagrams, and Bezier curve analysis), allows for a simplified analysis of the distribution of stress and strain, and enables and the analysis and visualization of folding associated fractures. However, in a heterogenous medium folds have to terminate somewhere, resulting in more complex three-dimensional geometries. In this study, a 3D finite element modeling approach using a Maxwell visco-elastic rheology is utilized to simulate 3D periclinal folds resulting from single layer buckle folding. With respect to fold shape analysis, we use the forward modeled pericline geometries to demonstrate that geometrical attitude data collected for various cross sections and plotted using traditional 2D methods such as stereographs and tangent diagrams may lead to the misinterpretation of the fold shape as conical. In contrast 3D geometric data such as Gaussian curvature can describe and quantify the 3D fold geometry in its entirety. With respect to folding associated fracture analysis, the 3D modeling results show that shear fractures of various orientations in the fold limb, which cannot be intuitively explained by the strain/stress regimes during 2D buckling and require unrealistic boundary conditions, are feasible to occur during a single deformation event during the development of a pericline. In summary, accounting for the true 3D geometry of buckle fold structures will lead to a better classification of folds, a better understanding of the processes and parameters affecting their development, and enable post-folding failure analysis.</p>

Three dimensional simulation of air permeability of single layer woven structures

2011 ◽  
Vol 1 (4) ◽  
Author(s):  
Radostina Angelova ◽  
Peter Stankov ◽  
Iskra Simova ◽  
Idoya Aragon
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Single Layer ◽  
Woven Fabrics ◽  
Transverse Permeability ◽  
Woven Structures ◽  
Dimensional Simulation ◽  
Jet Cross Sections ◽  
Woven Structure

AbstractThe paper deals with a CFD based study of the transverse permeability of a textile woven structure. The reported numerical investigation is preconditioned by both previous experimental and CFD study on jet systems. It is also based on detailed experimental investigation of the porous structure of single layer woven fabrics, made of staple fiber yarns. The flow in through-thickness direction of the woven structures is presented as jet systems, issuing from set of orifices. Two different types of jet system (3×3 jets and 5×5 jets) with two types of jet cross sections (square and circular), corresponding to two different woven structures, are simulated. An analysis is made in terms of the structure of the woven fabrics (area and shape of the interstices between the threads), the parameters of the flow passing through the textile (velocity profiles and velocity fields through isosurfaces), the role of the type of the jet systems, representing the flow and the influence of the shape of the interstices between the threads on the flow pattern. It was found that the applied approach could be effectively used for studying of the transverse permeability of the woven fabrics.

Single-layer planar on-chip flow cytometer using microfluidic drifting based three-dimensional (3D) hydrodynamic focusing

Lab on a Chip ◽  
2009 ◽  
Vol 9 (11) ◽  
pp. 1583 ◽  
Author(s):  
Xiaole Mao ◽  
Sz-Chin Steven Lin ◽  
Cheng Dong ◽  
Tony Jun Huang
Keyword(s):  
Three Dimensional ◽  
Single Layer ◽  
Flow Cytometer ◽  
Hydrodynamic Focusing ◽  
Chip Flow ◽  
On Chip

STATIC AND DYNAMIC BEHAVIOUR OF LAMINATED COMPOSITE BEAMS

2001 ◽  
Vol 01 (04) ◽  
pp. 545-560 ◽  
Author(s):  
M. A. RAMOS LOJA ◽  
J. INFANTE BARBOSA ◽  
C. M. MOTA SOARES
Keyword(s):  
Cross Sections ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Shear Deformation Theory ◽  
Single Layer ◽  
Laminated Composite ◽  
Element Model ◽  
Composite Beams ◽  
Straight Beam ◽  
Transverse Stresses

A higher order shear deformation theory, assuming a non-linear variation for the displacement field, is used to develop a finite element model to predict static and free vibration behaviour of anisotropic multilaminated thick and thin beams. The model is based on a single-layer Lagrangean four-node straight beam element with fourteen degrees of freedom per node. It considers bending into two orthogonal planes, stretching and twisting to enable three-dimensional analysis of frames. The most common cross sections and symmetric and asymmetric lay-ups are studied. The behaviour of the model is tested on thin and thick isotropic and composite beams. Comparisons show that the model is accurate and versatile. The good performance of the present model is evident on the prediction of displacements, normal and transverse stresses and natural frequencies of thin and thick isotropic or anisotropic beam structures.

Universally applicable three-dimensional hydrodynamic focusing in a single-layer channel for single cell analysis

2018 ◽  
Vol 10 (28) ◽  
pp. 3489-3497 ◽  
Author(s):  
Yingying Zhao ◽  
Qin Li ◽  
Xiaoming Hu
Keyword(s):  
Single Cell ◽  
Single Cell Analysis ◽  
Three Dimensional ◽  
Single Layer ◽  
Optical Systems ◽  
Cell Analysis ◽  
Hydrodynamic Focusing ◽  
Integrated Optical ◽  
Microfluidic Structure

A microfluidic cytometer which integrated 3D hydrodynamic focusing and integrated optical systems on a single-layer microfluidic structure was demonstrated.

scholarly journals Flow patterns over vegetation patches in the natural channel

2018 ◽  
Vol 40 ◽  
pp. 02059
Author(s):  
Yonguk Ryu ◽  
Joongu Kang ◽  
Un Ji ◽  
Sanghwa Jung ◽  
Changlae Jang ◽  
...  
Keyword(s):  
Cross Sections ◽  
Longitudinal Velocity ◽  
Three Dimensional ◽  
Acoustic Doppler Current Profiler ◽  
Low Flow ◽  
Cross Sectional ◽  
Hydraulic Conditions ◽  
Current Profiler ◽  
Vegetation Patches ◽  
Submerged Conditions

This study carried out experiments to investigate the effects of vegetation patches of rooted willows on the flow pattern. Stream-scale experiments on vegetated flows were performed for various hydraulic conditions: emergent and submerged conditions of vegetation. Vegetation patches were arranged by alternative bar formation and the flows in vegetated and non-vegetated sections were compared. Three-dimensional flow velocity was measured by ADV (Acoustic Doppler Velocimeter) and ADCP (Acoustic Doppler Current Profiler). Vertical, cross-sectional, and longitudinal velocity distributions were provided for different hydraulic conditions at various points. Flow velocities through the sparse patch were similar to those of non-vegetation area for low flow condition of emergent vegetation. Dense and submerged vegetation produced more complicated and non-uniform flows over the cross-sections of vegetation patches.

Sign in / Sign up

Export Citation Format

Share Document