scholarly journals Diffusiophoretically induced interactions between chemically active and inert particles

Soft Matter ◽  
2018 ◽  
Vol 14 (29) ◽  
pp. 6043-6057 ◽  
Author(s):  
Shang Yik Reigh ◽  
Prabha Chuphal ◽  
Snigdha Thakur ◽  
Raymond Kapral
Keyword(s):  
Concentration Gradient ◽  
Active Particle ◽  
Inert Particle ◽  
Inert Particles

In the presence of a chemically active particle, a nearby chemically inert particle can respond to a concentration gradient and move by diffusiophoresis.

Constrained network model for predicting densification behavior of composite powders

1987 ◽  
Vol 2 (1) ◽  
pp. 59-65 ◽  
Author(s):  
F. F. Lange
Keyword(s):  
Network Model ◽  
Powder Compact ◽  
Volume Fraction ◽  
Random Network ◽  
Simple Relation ◽  
Unit Cell ◽  
Densification Behavior ◽  
Inert Particle ◽  
Composite Powders ◽  
Inert Particles

Inert particles that do not contribute to the densification of a composite powder compact are visualized as located on network sites; the network is defined by the distribution of the particles in the powder matrix. Because the distances between neighboring network sites are not identical, the strain produced by the sintering powder between all inert particle pairs cannot be the same as that for the powder compact without the inert particles. The constrained network model is based on the hypothesis that the densification of the composite will be constrained by the network and will mimic that of the network. The shrinkage of the network, and thus the densification of the composite, is estimated with a periodic network. A distance between the minimum and maximum site pairs within the unit cell defines the distance between site pairs in the random network where the powder between the particles densifies in the same manner as that for the powder without the inert particle. When the particles form a continuous touching network, composite shrinkage and densification is nil. The chosen lattice must also conform to this condition. A simple relation was developed relating the densification behavior of the composite to that of the matrix without the inert particles and the parameter associated with the chosen lattice. By choosing the lattice formed by the tetrakaidecahedron unit cell (volume fraction of particles for a touching network = 0.277), remarkable agreement was achieved for the experimental data concerning the densification behavior of the ZnO/SiC composite system reported by De Jonghe et al. [L. C. De Jonghe, M. N. Rahaman, and C. H. Hsueh, Acta Metall. 34, 1467 (1986)]. The universal nature of this lattice for other composites is discussed with respect to site percolation theory. The application of this concept to powder compacts containing either whiskers or agglomerates is briefly discussed.

scholarly journals Motion of an active particle in a linear concentration gradient

2021 ◽  
Vol 33 (3) ◽  
pp. 032011
Author(s):  
Prathmesh M. Vinze ◽  
Akash Choudhary ◽  
S. Pushpavanam
Keyword(s):  
Concentration Gradient ◽  
Active Particle ◽  
Linear Concentration

Aggregation of Platelets and Inert Particles Induced by Thrombin

1976 ◽  
Vol 35 (03) ◽  
pp. 717-736 ◽  
Author(s):  
Frangis C. Chao ◽  
James L. Tullis ◽  
Gail S. Conneely ◽  
John W. Lawler
Keyword(s):  
Platelet Aggregation ◽  
Light Transmission ◽  
Direct Interaction ◽  
Second Phase ◽  
Inert Particle ◽  
Coagulation Mechanism ◽  
Inert Particles ◽  
Platelet Aggregates ◽  
Second Wave

SummaryThrombin-induced platelet aggregation and release were investigated in washed platelet suspensions and in suspensions of inert particles in order to evaluate the role of fibrinogen-fi-brin transformation in aggregometer tracings. Thrombin (0.25–2.0 U/ml) produced two waves of light transmission increase (LTI) in both platelet and inert particle suspensions containing fibrinogen, and concomittantly aggregates were observed under phase microscopy. Without fibrinogen, thrombin induced rapid release of platelet ADP but failed to cause second wave of LTI. The kinetics of LTI in platelet and inert particle systems were related to both thrombin and fibrinogen concentrations. A rapid second wave of LTI could be produced by direct interaction of thrombin-treated platelets or inert particles with polymerizing fibrin, and was inhibited by sodium sulfite and low pH of 5.1 which prevent fibrin monomer polymerization. No fibrin strands were noted in platelet aggregates fixed at the completion of the second wave of LTI. Apyrase and PGE1 inhibited the rate of first but not that of second wave LTI. The results suggest that the release of platelet ADP induced by thrombin primarily affects the first phase aggregation, and the second phase may result from interaction of thrombin-exposed platelets and polymerizing fibrin. Thus, the blood coagulation mechanism may be directly involved in platelet aggregation.

Influence of free convection on the diffusion current to a sphere in a laminar forced flow regime

1985 ◽  
Vol 50 (12) ◽  
pp. 2697-2714
Author(s):  
Arnošt Kimla ◽  
Jiří Míčka
Keyword(s):  
Asymptotic Expansion ◽  
Free Convection ◽  
Boundary Value Problem ◽  
Concentration Gradient ◽  
Empirical Formula ◽  
Convective Diffusion ◽  
Forced Flow ◽  
Diffusion Current ◽  
Wide Range ◽  
Free And Forced Convection

The formulation and solution of a boundary value problem is presented, describing the influence of the free convective diffusion on the forced one to a sphere for a wide range of Rayleigh, Ra, and Peclet, Pe, numbers. It is assumed that both the free and forced convection are oriented in the same sense. Numerical results obtained by the method of finite differences were approximated by an empirical formula based on an analytically derived asymptotic expansion for Pe → ∞. The concentration gradient at the surface and the total diffusion current calculated from the empirical formula agree with those obtained from the numerical solution within the limits of the estimated errors.

scholarly journals A Photochemically Active Particle Derived from Chloroplasts by the Action of the Detergent Triton X-100

1966 ◽  
Vol 241 (17) ◽  
pp. 4101-4109
Author(s):  
Leo P. Vernon ◽  
Elwood R. Shaw ◽  
Bacon Ke
Keyword(s):  
Active Particle ◽  
Triton X
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