scholarly journals Theoretical Analysis of Fractional Viscoelastic Flow in Circular Pipes: General Solutions

2020 ◽  
Vol 10 (24) ◽  
pp. 9093
Author(s):  
Dmitry Gritsenko ◽  
Roberto Paoli
Keyword(s):  
Fractional Calculus ◽  
Biomedical Applications ◽  
Viscoelastic Flow ◽  
Shear Stresses ◽  
Viscoelastic Flows ◽  
Extensive Literature ◽  
Circular Pipes ◽  
Different Types ◽  
Pipe Radius ◽  
Fractional Orders

Fractional calculus is a relatively old yet emerging field of mathematics with the widest range of engineering and biomedical applications. Despite being an incredibly powerful tool, it, however, requires promotion in the engineering community. Rheology is undoubtedly one of the fields where fractional calculus has become an integral part of cutting-edge research. There exists extensive literature on the theoretical, experimental, and numerical treatment of various fractional viscoelastic flows in constraint geometries. However, the general theoretical approach that unites several most commonly used models is missing. Here we present exact analytical solutions for fractional viscoelastic flow in a circular pipe. We find velocity profiles and shear stresses for fractional Maxwell, Kelvin–Voigt, Zener, Poynting–Thomson, and Burgers models. The dynamics of these quantities are studied with respect to normalized pipe radius, fractional orders, and elastic moduli ratio. Three different types of behavior are identified: monotonic increase, resonant, and aperiodic oscillations. The models developed are applicable in the widest material range and allow for the alteration of the balance between viscous and elastic properties of the materials.

scholarly journals Theoretical Analysis of Fractional Viscoelastic Flow in Circular Pipes: Parametric Study

2020 ◽  
Vol 10 (24) ◽  
pp. 9080
Author(s):  
Dmitry Gritsenko ◽  
Roberto Paoli
Keyword(s):  
Fluid Dynamics ◽  
Pipe Flow ◽  
Mutual Influence ◽  
Viscoelastic Flow ◽  
Elastic Parameters ◽  
Time Dynamics ◽  
Circular Pipes ◽  
Classical Models ◽  
Fractional Orders ◽  
Limiting Value

Pipe flow is one of the most commonly used models to describe fluid dynamics. The concept of fractional derivative has been recently found very useful and much more accurate in predicting dynamics of viscoelastic fluids compared with classic models. In this paper, we capitalize on our previous study and consider space-time dynamics of flow velocity and stress for fractional Maxwell, Zener, and Burgers models. We demonstrate that the behavior of these quantities becomes much more complex (compared to integer-order classical models) when adjusting fractional order and elastic parameters. We investigate mutual influence of fractional orders and consider their limiting value combinations. Finally, we show that the models developed can be reduced to classical ones when appropriate fractional orders are set.

A high-density nanowire electrode on paper for biomedical applications

RSC Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 8680-8687 ◽  
Author(s):  
P. Mostafalu ◽  
S. Sonkusale
Keyword(s):  
Biomedical Applications ◽  
High Density ◽  
Different Types ◽  
Paper Substrates

Different types of nanowires made from platinum, nickel and copper are fabricated and patterned with microscale resolution on paper substrates and employed for biomedical applications.

The Mechanism of Size-Based Particle Separation by Dielectrophoresis in the Viscoelastic Flows

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Teng Zhou ◽  
Yongbo Deng ◽  
Hongwei Zhao ◽  
Xianman Zhang ◽  
Liuyong Shi ◽  
...  
Keyword(s):  
Electric Field ◽  
Newtonian Fluid ◽  
Finite Size ◽  
Particle Separation ◽  
Weissenberg Number ◽  
Viscoelastic Flow ◽  
Viscoelastic Flows ◽  
Arbitrary Lagrangian Eulerian ◽  
Particle Movement ◽  
Physical Insight

Viscoelastic solution is encountered extensively in microfluidics. In this work, the particle movement of the viscoelastic flow in the contraction–expansion channel is demonstrated. The fluid is described by the Oldroyd-B model, and the particle is driven by dielectrophoretic (DEP) forces induced by the applied electric field. A time-dependent multiphysics numerical model with the thin electric double layer (EDL) assumption was developed, in which the Oldroyd-B viscoelastic fluid flow field, the electric field, and the movement of finite-size particles are solved simultaneously by an arbitrary Lagrangian–Eulerian (ALE) numerical method. By the numerically validated ALE method, the trajectories of particle with different sizes were obtained for the fluid with the Weissenberg number (Wi) of 1 and 0, which can be regarded as the Newtonian fluid. The trajectory in the Oldroyd-B flow with Wi = 1 is compared with that in the Newtonian fluid. Also, trajectories for different particles with different particle sizes moving in the flow with Wi = 1 are compared, which proves that the contraction–expansion channel can also be used for particle separation in the viscoelastic flow. The above results for this work provide the physical insight into the particle movement in the flow of viscous and elastic features.

Surface Modification of Gold Nanostars Through the Changes on Gold Seed Concentrations

MRS Advances ◽  
2018 ◽  
Vol 3 (41) ◽  
pp. 2449-2454
Author(s):  
Juan Carlos Martinez Espinosa ◽  
Miguel Jose Yacaman ◽  
German Plascencia Villa ◽  
Victor Hugo Romero Arellano ◽  
Ana Karen Zavala Raya
Keyword(s):  
Biomedical Applications ◽  
Surface Enhanced Raman Spectroscopy ◽  
Diameter Distribution ◽  
Biological Assays ◽  
Surface Enhanced ◽  
Different Types ◽  
Surface Enhanced Raman ◽  
Gold Seed ◽  
Gold Nanomaterials ◽  
Specific Membrane

AbstractDue to its excellent optical properties, gold nanomaterials with anisotropic morphology are playing an important role in biomedical applications, specifically in the use of Surface Enhanced Raman Spectroscopy (SERS) technique for biological assays. In this work, we verified the behavior of the star shape nanoparticle peaks obtained by chemical synthesis (precursor reactant: HAuCl4, cationic surfactant: CTAB) and whose peaks were formed from the different concentrations of gold seeds (55, 65, 75 and 85 ul) which were added to the total solution (5.275 ml). The shape and size of the nanoparticles was verified with a Hitachi S-5500 microscope with a BF & DF SEM / STEM detector, and for the diameter distribution (hydrodynamic) was carried out by the dynamic light distribution technique with a Malvern DLS system Zetasizer Nano ZS. Particle sizes (peak-to-peak considering) were obtained with variations from 107 to 166 nm. The results suggest adding 75 ul of gold seeds to obtain uniform nanostars with well defined peaks. These gold nano-stars could be applied for identification of specific membrane markers for the study of different types of cancer by the SERS technique.

Axisymmetric Stress Analysis and Strength Evaluation of Bonded Shrink Fitted Joints of Circular Pipes Subjected to Internal Pressure and Tensile Loads

2000 ◽  
Author(s):  
Masahide Katsuo ◽  
Toshiyuki Sawa ◽  
Masahiro Yoneno
Keyword(s):  
Internal Pressure ◽  
Stress Analysis ◽  
Joint Strength ◽  
Tensile Load ◽  
Theory Of Elasticity ◽  
Shear Stresses ◽  
Stress Distributions ◽  
Strength Evaluation ◽  
Circular Pipes ◽  
Hollow Cylinders

Abstract This study deals with the stress analysis and the strength evaluation of a bonded shrink fitted joint of circular pipes subjected to an internal pressure and a tensile load. In the analysis, two pipes and the adhesive are replaced with finite hollow cylinders, and the stress distributions in the joint are analyzed by using the axisymmetric theory of elasticity. From the numerical calculations, the following results are obtained: (1) Both the compressive and shear stresses at the interface between the adherend and the adhesive increase as Young’s modulus of the adherend increases. (2) The stress becomes singular at the edges of the interfaces. (3) The joint strength can be evaluated using the compressive and shear stresses near the edge of the interface. In the experiments, bonded shrink fitted joints consisting of dissimilar circular pipes were manufactured, and rupture tests of the joints were carried out by applying an internal pressure, and a tensile load to the joints. From the results, the joint strength of the bonded shrink fitted joint was found to be greater than that of the shrink fitted joint. Furthermore, the numerical results are in fairly good agreement with the experimental ones.

Applications of Nanomaterials for Activation and Suppression of Immune Responses

2015 ◽  
pp. 205-220
Author(s):  
Akhilesh Kumar Shakya ◽  
Kutty Selva Nandakumar
Keyword(s):  
Side Effects ◽  
Immune Responses ◽  
Biomedical Applications ◽  
Inflammatory Diseases ◽  
Host Proteins ◽  
Different Types ◽  
Potential Therapeutics

Evaluation of immuno-modulating properties of nanomaterials is important to develop new potential therapeutics for inflammatory diseases and cancer. Activation and suppressive effects of nanomaterials on immune responses occur through various interactions with different host proteins. They can also be engineered as carriers and/or adjuvants for different proteins or antigens. Particles, emulsions, and tubes/rods are the major formats of nanomaterials currently used in biomedical applications. Sometimes, nanomaterials induce side effects like undesired immunosuppression and toxicities, which are major concerns at present in designing optimal nanotherapeutics. This chapter summarizes different types of nanomaterials and their effect on immune responses.

Applications of Nanomaterials for Activation and Suppression of Immune Responses

2017 ◽  
pp. 859-875
Author(s):  
Akhilesh Kumar Shakya ◽  
Kutty Selva Nandakumar
Keyword(s):  
Side Effects ◽  
Immune Responses ◽  
Biomedical Applications ◽  
Inflammatory Diseases ◽  
Host Proteins ◽  
Different Types ◽  
Potential Therapeutics

Evaluation of immuno-modulating properties of nanomaterials is important to develop new potential therapeutics for inflammatory diseases and cancer. Activation and suppressive effects of nanomaterials on immune responses occur through various interactions with different host proteins. They can also be engineered as carriers and/or adjuvants for different proteins or antigens. Particles, emulsions, and tubes/rods are the major formats of nanomaterials currently used in biomedical applications. Sometimes, nanomaterials induce side effects like undesired immunosuppression and toxicities, which are major concerns at present in designing optimal nanotherapeutics. This chapter summarizes different types of nanomaterials and their effect on immune responses.

Lack of null controllability of viscoelastic flows

2019 ◽  
Vol 25 ◽  
pp. 60
Author(s):  
Debayan Maity ◽  
Debanjana Mitra ◽  
Michael Renardy
Keyword(s):  
Approximate Controllability ◽  
Momentum Equation ◽  
Null Controllability ◽  
Viscoelastic Flow ◽  
Viscoelastic Flows ◽  
Relaxation Mode ◽  
Maxwell Fluids ◽  
Linear Viscoelastic ◽  
Exact Null Controllability

We consider controllability of linear viscoelastic flow with a localized control in the momentum equation. We show that, for Jeffreys fluids or for Maxwell fluids with more than one relaxation mode, exact null controllability does not hold. This contrasts with known results on approximate controllability.

scholarly journals Plasma and Nanomaterials: Fabrication and Biomedical Applications

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 98 ◽  
Author(s):  
Nagendra Kaushik ◽  
Neha Kaushik ◽  
Nguyen Linh ◽  
Bhagirath Ghimire ◽  
Anchalee Pengkit ◽  
...  
Keyword(s):  
Thermal Plasma ◽  
Reactive Nitrogen Species ◽  
Biomedical Applications ◽  
Medical Personnel ◽  
Plasma Jets ◽  
Dielectric Barrier Discharges ◽  
Different Types ◽  
Non Thermal Plasma ◽  
Review Reports ◽  
Barrier Discharges

Application of plasma medicine has been actively explored during last several years. Treating every type of cancer remains a difficult task for medical personnel due to the wide variety of cancer cell selectivity. Research in advanced plasma physics has led to the development of different types of non-thermal plasma devices, such as plasma jets, and dielectric barrier discharges. Non-thermal plasma generates many charged particles and reactive species when brought into contact with biological samples. The main constituents include reactive nitrogen species, reactive oxygen species, and plasma ultra-violets. These species can be applied to synthesize biologically important nanomaterials or can be used with nanomaterials for various kinds of biomedical applications to improve human health. This review reports recent updates on plasma-based synthesis of biologically important nanomaterials and synergy of plasma with nanomaterials for various kind of biological applications.

scholarly journals Determination of Cohesion values of Rock Materials using Double Shear Jaws

2018 ◽  
Author(s):  
Eren Komurlu ◽  
Aysegul Durmus Demir
Keyword(s):  
Failure Mechanisms ◽  
Shear Stresses ◽  
Compressive Test ◽  
Contact Conditions ◽  
Testing Conditions ◽  
Rock Materials ◽  
Double Shear ◽  
Different Types ◽  
Shear Planes

In this study, experimental and numerical analyses were carried out for determination of cohesion values of different types of rock materials using double shear jaws (DSJ) which can be practically used with the conventional compressive test equipment, to make shear planes in the rock core specimens. Effects of various parameters like jaw dimensions, gaps between triple blocks of the DSJ and contact conditions of the jaw on the results and validity of the cohesion test were investigated considering failure mechanisms of rock core specimens. Instead of a failure induced due to the shear stresses, tensile failures are mostly seen from conventional shear testing conditions. For a valid failure under the control of shear stresses, a DSJ design was suggested to be used in cohesion determination tests according to the results obtained from this study.

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