scholarly journals Mathematical Model Represents the Effect of Flexible Endoscopy on Suspension Fluid Flow

2021 ◽  
Vol 89 (1) ◽  
pp. 42-61
Author(s):  
Amal Bahnasy ◽  
A. M. Abdel-Wahab
Keyword(s):  
Traveling Wave ◽  
Flexible Endoscopy ◽  
Industrial Applications ◽  
Spherical Particles ◽  
Friction Forces ◽  
Long Wavelength ◽  
Peristaltic Pumping ◽  
Special Cases ◽  
Wavelength Approximation ◽  
Future Work

In this manuscript, peristaltic transport induced by a sinusoidal traveling wave in the case for a viscous incompressible Newtonian fluid mixed with rigid spherical particles in the presence of a flexible inner tube, where the inner tube is also moving with a sinusoidal traveling wave of moderate amplitude is studied. The governing equations of the mixture (fluid-particle suspension) are written in two-dimensional cylindrical coordinates. The long-wavelength approximation is used to simplify the system of equations (d<<1). The velocities distribution for both fluid and particles are obtained and evaluated numerically with discussion for special cases. The flow rate, pressure drop, friction forces and shear stress at the outer and inner walls of tubes are derived and represented graphically. In the urinary system, peristalsis is due to involuntary muscular contractions of the ureter wall which drives urine from the kidneys to the bladder through the ureters. A mathematical analysis of peristaltic flow with application to the ureter in presence of flexible endoscopy (Peristaltic Endoscope) is taken as a real application in this study. Finally, conclusions of the research and recommendations for future work are discussed. The results obtained may be relevant to the transport of other physiological fluids and industrial applications in which peristaltic pumping is used.

Peristaltic thrusting of a thermal-viscosity nanofluid through a resilient vertical pipe

2020 ◽  
Vol 75 (8) ◽  
pp. 727-738 ◽  
Author(s):  
Ramzy M. Abumandour ◽  
Islam M. Eldesoky ◽  
Mohamed H. Kamel ◽  
Mohamed M. Ahmed ◽  
Sara I. Abdelsalam
Keyword(s):  
Pressure Gradient ◽  
Hartmann Number ◽  
Amplitude Ratio ◽  
Variable Viscosity ◽  
Friction Forces ◽  
Long Wavelength ◽  
Viscosity Parameter ◽  
Long Wavelength Approximation ◽  
Wavelength Approximation ◽  
Theoretical Results

AbstractIn the article, the effects of the thermal viscosity and magnetohydrodynamic on the peristalsis of nanofluid are analyzed. The dominant neutralization is deduced through long wavelength approximation. The analytical solution of velocity and temperature is extracted by using steady perturbation. The pressure gradient and friction forces are obtained. Numerical results are calculated and contrasted with the debated theoretical results. These results are calculated for various values of Hartmann number, variable viscosity parameter and amplitude ratio. It is observed that the pressure gradient is reduced with an increase in the thermal viscosity parameter and that the Hartmann number enhances the pressure difference.

scholarly journals Peristaltic Transport of a Particle–Fluid Suspension through a Uniform and Non-Uniform Annulus

2008 ◽  
Vol 5 (2) ◽  
pp. 47-57 ◽  
Author(s):  
K. S. Mekheimer ◽  
Y. Abd Elmaboud
Keyword(s):  
Amplitude Ratio ◽  
Pressure Rise ◽  
Fluid Phase ◽  
Spherical Particles ◽  
Physical Parameters ◽  
Pressure Gradients ◽  
Long Wavelength ◽  
Long Wavelength Approximation ◽  
Wavelength Approximation ◽  
Uniform Tube

This study looks at the influence of an endoscope on the peristaltic flow of a particle–fluid suspension (as blood model) through tubes. A long wavelength approximation through a uniform and non-uniform infinite annulus filled with an incompressible viscous and Newtonian fluid mixed with rigid spherical particles of identical size is investigated theoretically. The inner tube is uniform, rigid and moving with a constant velocity V0, whereas the outer non-uniform tube has a sinusoidal wave travelling down its wall. The axial velocity of the fluid phase uf, particulate phase upand the pressure gradients have been obtained in terms of the dimensionless flow rateQ, the amplitude ratioɸ, particle concentrationC, the velocity constant V0and the radius ratio ϵ (the ratio between the radius of the inner tube and the radius of the outer one at the inlet). Numerical calculations for various values of the physical parameters of interest are carried out for the pressure rise and the friction force on the inner and the outer tubes.

scholarly journals A highly thermotolerant laccase produced by Cerrena unicolor strain CGMCC 5.1011 for complete and stable malachite green decolorization

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yanhua Yao ◽  
Guimei Zhou ◽  
Yonghui Lin ◽  
Xinqi Xu ◽  
Jie Yang
Keyword(s):  
Malachite Green ◽  
Fermentation Broth ◽  
Nitrogen Sources ◽  
Life Time ◽  
Industrial Applications ◽  
Dynamics Simulation ◽  
Carbon And Nitrogen ◽  
Cdna Sequences ◽  
Cerrena Unicolor ◽  
Future Work

Abstract Laccases are a class of multi-copper oxidases with important industrial values. A thermotolerant laccase produced by a basidiomycete fungal strain Cerrena unicolor CGMCC 5.1011 was studied. With glycerin and peptone as the carbon and nitrogen sources, respectively, a maximal laccase activity of 121.7 U/mL was attained after cultivation in the shaking flask for 15 days. Transcriptomics analysis revealed an expressed laccase gene family of 12 members in C. unicolor strain CGMCC 5.1011, and the gene and cDNA sequences were cloned. A glycosylated laccase was purified from the fermentation broth of Cerrena unicolor CGMCC 5.1011 and corresponded to Lac2 based on MALDI-TOF MS/MS identification. Lac2 was stable at pH 5.0 and above, and was resistant to organic solvents. Lac2 displayed remarkable thermostability, with half-life time of 1.67 h at 70 ºC. Consistently, Lac2 was able to completely decolorize malachite green (MG) at high temperatures, whereas Lac7 from Cerrena sp. HYB07 resulted in accumulation of colored MG transformation intermediates. Molecular dynamics simulation of Lac2 was conducted, and possible mechanisms underlying Lac2 thermostability were discussed. The robustness of C. unicolor CGMCC 5.1011 laccase would not only be useful for industrial applications, but also provide a template for future work to develop thermostable laccases.

scholarly journals Crossbreed impact of double-diffusivity convection on peristaltic pumping of magneto Sisko nanofluids in non-uniform inclined channel: A bio-nanoengineering model

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110336
Author(s):  
Safia Akram ◽  
Maria Athar ◽  
Khalid Saeed ◽  
Alia Razia
Keyword(s):  
Mathematical Modeling ◽  
Magnetic Field ◽  
Physical Parameters ◽  
Induced Magnetic Field ◽  
Long Wavelength ◽  
Inclined Channel ◽  
Graphical Data ◽  
Peristaltic Pumping ◽  
Highly Nonlinear ◽  
Linear Pdes

The consequences of double-diffusivity convection on the peristaltic transport of Sisko nanofluids in the non-uniform inclined channel and induced magnetic field are discussed in this article. The mathematical modeling of Sisko nanofluids with induced magnetic field and double-diffusivity convection is given. To simplify PDEs that are highly nonlinear in nature, the low but finite Reynolds number, and long wavelength estimation are used. The Numerical solution is calculated for the non-linear PDEs. The exact solution of concentration, temperature and nanoparticle are obtained. The effect of various physical parameters of flow quantities is shown in numerical and graphical data. The outcomes show that as the thermophoresis and Dufour parameters are raised, the profiles of temperature, concentration, and nanoparticle fraction all significantly increase.

scholarly journals EN The wave model of secondary flows and coherent structures in pipes

2020 ◽  
Vol 55 (5-6) ◽  
pp. 273-281
Author(s):  
S. Surkov
Keyword(s):  
Wave Equation ◽  
Stream Function ◽  
Coherent Structures ◽  
Large Scale ◽  
Experimental Studies ◽  
Viscous Friction ◽  
Orthogonal Decomposition ◽  
Secondary Flows ◽  
Friction Forces ◽  
Special Cases

In this article, a theoretical analysis of the flows arising in the cross sections of fluid and gas flows is performed. Such flows are subdivided into secondary flows and coherent structures. From experimental studies it is known that both types of flows are long-lived large-scale movements (LSM) stretched along the flow. The relative stability of the vortices is traditionally explained by the fact that the viscous friction forces that inhibit the rotation are compensated by the intensification of the swirl when moving slowly rotating peripheral layers to the center of the vortex due to longitudinal tension. An analysis of this mechanism made it possible to develop a relatively simple model of vortex structures in which the viscous friction forces and axial expansion are considered to be infinitesimal. Under these assumptions, one can use the equations of motion of an ideal fluid in the variables “stream function - vorticity”. It is shown that under certain assumptions these equations take the form of a wave equation, and the boundary conditions are the condition that the stream function on the solid walls of the flow equals zero. The obtained solutions of the wave equation describe the following special cases: Goertler’s vortices between rotating cylinders, secondary flows in a pipe with a square cross section, swirling flow in a round pipe, paired vortex after bend of the pipe. The physical sense of more complex solutions of the wave equation has become clear relatively recently. Very similar structures were found in experimental studies using orthogonal decomposition (POD) of a turbulent pulsations field. This may mean that the eigenfunctions in the POD correspond to coherent structures that really arise in the flow. The results obtained confirm the hypothesis that secondary flows and coherent structures have a common nature. The solutions obtained in this paper can be used in processing the experiment as eigenfunctions for the orthogonal decomposition method. In addition, they can be used in direct numerical simulation (DNS) of turbulent flows

scholarly journals Industrial Automation using Zigbee Communication Protocol

2019 ◽  
Vol 8 (3) ◽  
pp. 7240-7243
Keyword(s):  
Wireless Communication ◽  
Ieee 802.11 ◽  
Industrial Application ◽  
Lower Cost ◽  
Communication Protocol ◽  
Industrial Applications ◽  
Video Content ◽  
Industrial Automation ◽  
Future Work ◽  
Wired Communication

If we compare wireless communication over wired communication, wireless communication offer more advantages when compared to wired communication such as lower cost, fast deployment, higher flexibility & scalability and mobile nature of system communicated wirelessly. In Industrial automation, industrial communication has very challenging requirements like packet deadline, low transmission jitter, etc. In some places wired communication is only accepted and it cannot be replaced by wireless communication. Industrial applications also run more flexible requirements applications such as email, Video content or any other application. Those services are known as Best Effort (BE) services. In order to do both the industrial application and BE services we have proposed Zigbee communication together with the IEEE 802.11 standard in this article along with comparison between the two standards using physical layer solutions. This Zigbee communication is performed using a industrial automation design and it leads to less power consumption. Result and analysis in terms of real time services is left as a future work in this paper. It is proposed that through Zigbee solution it is possible to obtain better result in certain cases than those achieved using IEEE 802.11 standards.

scholarly journals Heat Transfer Augmentation through Different Jet Impingement Techniques: A State-of-the-Art Review

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6458
Author(s):  
Liaqat Hussain ◽  
Muhammad Mahabat Khan ◽  
Manzar Masud ◽  
Fawad Ahmed ◽  
Zabdur Rehman ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Phase Change Materials ◽  
Jet Impingement ◽  
Target Surface ◽  
Industrial Applications ◽  
Heat Transfer Augmentation ◽  
Numerical Studies ◽  
Single Jet ◽  
Jet Nozzle ◽  
Future Work

Jet impingement is considered to be an effective technique to enhance the heat transfer rate, and it finds many applications in the scientific and industrial horizons. The objective of this paper is to summarize heat transfer enhancement through different jet impingement methods and provide a platform for identifying the scope for future work. This study reviews various experimental and numerical studies of jet impingement methods for thermal-hydraulic improvement of heat transfer surfaces. The jet impingement methods considered in the present work include shapes of the target surface, the jet/nozzle–target surface distance, extended jet holes, nanofluids, and the use of phase change materials (PCMs). The present work also includes both single-jet and multiple-jet impingement studies for different industrial applications.

scholarly journals Surface and subsurface contributions to the build-up of forces on bed particles

2018 ◽  
Vol 851 ◽  
pp. 558-572 ◽  
Author(s):  
Alessandro Leonardi ◽  
D. Pokrajac ◽  
F. Roman ◽  
F. Zanello ◽  
V. Armenio
Keyword(s):  
Mutual Influence ◽  
Subsurface Flow ◽  
Porous Wall ◽  
Industrial Applications ◽  
Solid Particles ◽  
Free Flow ◽  
Spherical Particles ◽  
Large Eddy ◽  
Lift Forces ◽  
Surface And Subsurface Flow

In nature and in many industrial applications, the boundary of a channel flow is made of solid particles which form a porous wall, so that there is a mutual influence between the free flow and the subsurface flow developing inside the pores. While the influence of the porous wall on the free flow has been well studied, less well characterized is the subsurface flow, due to the practical difficulties in gathering information in the small spaces given by the pores. It is also not clear whether the subsurface flow can host turbulent events able to contribute significantly to the build-up of forces on the particles, potentially leading to their dislodgement. Through large eddy simulations, we investigate the interface between a free flow and a bed composed of spherical particles in a cubic arrangement. The communication between surface and subsurface flow is in this case enhanced, with relatively strong turbulent events happening also inside the pores. After comparing the simulation results with a previous experimental work from a similar setting, the forces experienced by the boundary particles are analysed. While it remains true that the lift forces are largely dependent on the structure of the free flow, turbulence inside the pores can also give a significant contribution. Pressure inside the pores is weakly correlated to the pressure in the free flow, and strong peaks above and below a particle can happen independently. Ignoring the porous layer below the particle from the computations leads then in this case to an underestimation of the lift forces.

Phase Drift in Networks of Coupled Colpitts Oscillators

2021 ◽  
Vol 31 (04) ◽  
pp. 2130010
Author(s):  
Lourdes Coria ◽  
Horacio Lopez ◽  
Antonio Palacios ◽  
Visarath In ◽  
Patrick Longhini
Keyword(s):  
Collective Behavior ◽  
Traveling Wave ◽  
Scaling Law ◽  
Industrial Applications ◽  
Basins Of Attraction ◽  
Navigation Systems ◽  
Negative Effects ◽  
Phase Drift ◽  
Wide Range ◽  
Wave Patterns

In modern times, satellite-based global positioning and navigation systems, such as the GPS, include precise time-keeping devices, e.g. atomic clocks, which are crucial for navigation and for a wide range of economic and industrial applications. However, precise timing might not be available when the environment renders satellite equipment inoperable. In response to this critical need, we have been carrying out, over the past three years, theory and preliminary experiments [Buono et al., 2018a; Buono et al., 2018b; Palacios et al., 2020], towards developing a novel and inexpensive precision timing device that can function independently of GPS availability. The fundamental idea is to exploit collective behavior generated by networks of coupled nonlinear oscillators. Common sense may suggest that synchronized oscillations may lead to higher accuracy. Previous works show, however, that it is not synchronization but rather, traveling wave patterns, in which consecutive oscillators are out of phase by a constant amount, that can better reduce the negative effects of noise and material imperfections which cause phase drift. In this work we advance the state-of-art in the network-based concept by studying, mainly computationally, collective behavior in networks of Colpitts oscillators. These type of oscillators are chosen because they offer a wide range of advantages (such as the ability to tune up the oscillations over a broad frequency range). The results highlight the regions of parameter space, including coupling strength, where traveling wave patterns have the largest basins of attraction and the ability to reduce phase drift by a [Formula: see text] scaling law, where [Formula: see text] is the number of oscillators in the network. The results should also provide guidelines for follow-up design and fabrication tasks of a network-based technology for precision timing.

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