scholarly journals Long-wavelength fluctuations and static correlations in quasi-2D colloidal suspensions

Soft Matter ◽  
2019 ◽  
Vol 15 (20) ◽  
pp. 4087-4097 ◽  
Author(s):  
Bo Zhang ◽  
Xiang Cheng
Keyword(s):  
Colloidal Suspensions ◽  
Spherical Particles ◽  
Long Wavelength

Dynamics of quasi-2D colloidal suspensions of binary spherical particles (left) and ellipsoids (right) under circular confinement.

Non-Spheric Colloidal Suspensions in Three-Dimensional Space

1997 ◽  
Vol 08 (04) ◽  
pp. 985-997 ◽  
Author(s):  
Dewei Qi
Keyword(s):  
Reynolds Number ◽  
Dimensional Space ◽  
Low Reynolds Number ◽  
Paper Industry ◽  
Three Dimensional ◽  
Colloidal Suspensions ◽  
Solid Particles ◽  
Spherical Particles ◽  
Dynamic Simulations ◽  
Low Reynolds

The translation and rotation of non-spherical particles, such as ellipsoidal, cylindric or disk-like pigment particles, in a Couette flow system similar to a blade coating system in the paper industry6 have been successfully simulated by using the lattice-Boltzmann method combined with Newtonian dynamic simulations. Hydrodynamic forces and torques are obtained by the use of boundary conditions which match the moving surface of solid particles. Then Euler equations have been integrated to include three-dimensional rotations of the suspensions by using four quaternion parameters as generalized coordinates. The three-dimensional rotations have been clearly observed. Consequently, the motion of the particles suspended in fluids of both low-Reynolds-number and finite-Reynolds-number, up to several hundreds, has been studied. It appears that the 3D translation and rotation of the non-spherical particles are more clearly observed in a high-Reynolds-number fluid than in a low-Reynolds-number fluid.

The Properties of Polymers in Solution. X. Ultrafiltrations of Rubber Solutions

1939 ◽  
Vol 12 (4) ◽  
pp. 774-777
Author(s):  
Kurt H. Meyer ◽  
Jean Jeannerat
Keyword(s):  
Colloidal Suspensions ◽  
Spherical Particles ◽  
Accurate Data ◽  
Colloidal Solutions ◽  
Dilute Solutions ◽  
Chain Molecules

Abstract It is a recognized fact that ultrafiltration is one of the most valuable methods for the study and treatment of colloidal suspensions formed of compact spherical particles. Not only is it possible to separate this type of particle from a solvent by means of a suitable ultrafilter, but it is also possible to determine the size of the particles by means of calibrated ultrafilters. Up to the present time, however, ultrafiltration has been utilized very little in the study of chain molecules, and no accurate data are available on the behavior of colloidal solutions of chain molecules during ultrafiltration. In the following discussion, the results of some experiments on the ultrafiltration of rubber solutions are described. Dilute solutions of rubber in toluene can be separated completely into rubber and solvent by ultrafiltration under pressure through fine ultrafilters with pores as fine as about 50 ḿ (“Fine” Cellafiltres and Membranfiltres). Solutions of crepe and solutions of masticated rubber give the same results.

scholarly journals Co-Loaded Curcumin and Methotrexate Nanocapsules Enhance Cytotoxicity against Non-Small-Cell Lung Cancer Cells

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1913
Author(s):  
Loanda Aparecida Cabral Rudnik ◽  
Paulo Vitor Farago ◽  
Jane Manfron Budel ◽  
Amanda Lyra ◽  
Fernanda Malaquias Barboza ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Drug Release ◽  
Small Cell Lung Cancer ◽  
Cell Lung Cancer ◽  
Colloidal Suspensions ◽  
Chemotherapeutic Agents ◽  
Small Cell ◽  
Spherical Particles ◽  
Small Cell Lung

Background: As part of the efforts to find natural alternatives for cancer treatment and to overcome the barriers of cellular resistance to chemotherapeutic agents, polymeric nanocapsules containing curcumin and/or methotrexate were prepared by an interfacial deposition of preformed polymer method. Methods: Physicochemical properties, drug release experiments and in vitro cytotoxicity of these nanocapsules were performed against the Calu-3 lung cancer cell line. Results: The colloidal suspensions of nanocapsules showed suitable size (287 to 325 nm), negative charge (−33 to −41 mV) and high encapsulation efficiency (82.4 to 99.4%). Spherical particles at nanoscale dimensions were observed by scanning electron microscopy. X-ray diffraction analysis indicated that nanocapsules exhibited a non-crystalline pattern with a remarkable decrease of crystalline peaks of the raw materials. Fourier-transform infrared spectra demonstrated no chemical bond between the drug(s) and polymers. Drug release experiments evidenced a controlled release pattern with no burst effect for nanocapsules containing curcumin and/or methotrexate. The nanoformulation containing curcumin and methotrexate (NCUR/MTX-2) statistically decreased the cell viability of Calu-3. The fluorescence and morphological analyses presented a predominance of early apoptosis and late apoptosis as the main death mechanisms for Calu-3. Conclusions: Curcumin and methotrexate co-loaded nanocapsules can be further used as a novel therapeutic strategy for treating non-small-cell lung cancer.

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 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.

Determination of Limiting Flux and Threshold Pressure in Stirred Ultrafiltration of Colloidal Suspensions

1997 ◽  
Vol 62 (9) ◽  
pp. 1413-1422
Author(s):  
Goran T. Vladisavljevic ◽  
Vladeta Lj. Pavasovic
Keyword(s):  
Experimental Data ◽  
Pressure Difference ◽  
Colloidal Suspensions ◽  
Average Diameter ◽  
Membrane Resistance ◽  
Spherical Particles ◽  
Working Fluid ◽  
Threshold Pressure ◽  
Permeate Flux ◽  
Polarization Model

The stationary permeate flux during ultrafiltration of colloidal suspensions reaches a limiting value, Jl, at high pressure differences. According to the gel polarization model employed here, the existence of this limiting flux is a consequence of gelation of the solution at the membrane-solution interface. The limiting permeate flux, Jl, can easily be determined from experimental data by plotting ∆p/Js against ∆p. Furthermore, the membrane resistance at zero pressure difference, Rm0, and the pressure difference necessary to reach 95 per cent of the limiting flux, i.e. the threshold pressure, ∆pt, may be calculated, too. The agreement between the model and experimental data is satisfactory. The laboratory-made silica sol consisting of uniform spherical particles with a surface average diameter of 18 nm was selected as a working fluid throughout this study.

scholarly journals Divergence of the long-wavelength collective diffusion coefficient in quasi-one- and quasi-two-dimensional colloidal suspensions

2014 ◽  
Vol 89 (2) ◽  
Author(s):  
Binhua Lin ◽  
Bianxiao Cui ◽  
Xinliang Xu ◽  
Ronen Zangi ◽  
Haim Diamant ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Colloidal Suspensions ◽  
Two Dimensional ◽  
Long Wavelength
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