A theoretical model of turbulent fiber suspension and its application to the channel flow

2010 ◽  
Vol 53 (9) ◽  
pp. 1659-1670 ◽  
Author(s):  
JianZhong Lin ◽  
SuHua Shen
Keyword(s):  
Theoretical Model ◽  
Channel Flow ◽  
Fiber Suspension ◽  
Turbulent Fiber Suspension

NUMERICAL RESEARCH ON THE EFFECT OF FIBERS ON THE PROPERTY OF TURBULENT FIBER SUSPENSION IN A CHANNEL

2009 ◽  
Vol 23 (03) ◽  
pp. 509-512 ◽  
Author(s):  
SUHUA SHEN ◽  
JIANZHONG LIN
Keyword(s):  
Reynolds Number ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Channel Flow ◽  
Turbulent Channel Flow ◽  
Fiber Suspension ◽  
Additional Stress ◽  
Mean Velocity ◽  
Navier Stokes Equation ◽  
Fiber Concentration

To explore the rheological property in turbulent channel flow of fiber suspensions, the equation of probability distribution function for mean fiber orientation and the Reynolds averaged Navier-Stokes equation with the term of additional stress resulted from fibers were solved with numerical methods to get the distributions of the mean velocity and turbulent kinetic energy. The simulation results show that the effect of fibers on turbulent channel flow is equivalent to an additional viscosity. The turbulent velocity profiles of fiber suspension become gradually sharper by increasing the fiber concentration and/or decreasing the Reynolds number. The turbulent kinetic energy will increase with increasing Reynolds number and fiber concentration.

scholarly journals CFD simulation of a turbulent fiber suspension flow – a modified near-wall treatment

2015 ◽  
Vol 9 (1) ◽  
pp. 233-246 ◽  
Author(s):  
Carla Cotas ◽  
Dariusz Asendrych ◽  
Fernando Garcia ◽  
Pedro Faia ◽  
Maria Graça Rasteiro
Keyword(s):  
Cfd Simulation ◽  
Fiber Suspension ◽  
Suspension Flow ◽  
Fiber Suspension Flow ◽  
Turbulent Fiber Suspension ◽  
Near Wall

Reactivity of Pulmonary Alveolar Cells to Crocidolite Asbestos Fibers

1982 ◽  
Vol 40 ◽  
pp. 334-335
Author(s):  
Charles L. Sanders ◽  
Roy R. Adee
Keyword(s):  
Osmium Tetroxide ◽  
Intratracheal Instillation ◽  
Uranyl Acetate ◽  
Fiber Suspension ◽  
Nacl Solution ◽  
Alveolar Cells ◽  
Asbestos Fibers ◽  
Fischer Rats ◽  
Mineral Silicates

Asbestos is a generic name for a group of hydrated mineral silicates that occur naturally in a fibrous form. The early interactions of asbestos fibers with alveolar cells in large part determines their long-term toxicity. Young adult, SPF, Fischer rats were given a single intratracheal instillation of 2 mg crocidolite asbestos suspended in 0.5 ml of 0.9% NaCl solution. About 80% of the fibers had lengths of less than 10 ym as measured on light micrographs of the fiber suspension. Two rats were killed at 3 hr, 1 d and 1, 4, 8, 12 and 16 wk after instillation and the lungs instilled with 8 ml McDowell - Trumps at 20 cm H2O. Lung tissue was dehydrated and sputtered coated with palladium-gold for SEM or post-fixed in osmium tetroxide, embedded in epoxy resin and sections stained with uranyl acetate and lead citrate for TEM.

A Model for Analyzing Suicide Prevention

Crisis ◽  
2000 ◽  
Vol 21 (2) ◽  
pp. 80-89 ◽  
Author(s):  
Maila Upanne
Keyword(s):  
Risk Factors ◽  
Theoretical Model ◽  
Protective Factors ◽  
Suicide Prevention ◽  
Suicide Risk ◽  
Practical Work ◽  
Individual Risk ◽  
Self Assessment ◽  
Prevention Project ◽  
Individual Risk Factors

This study monitored the evolution of psychologists' (n = 31) conceptions of suicide prevention over the 9-year course of the National Suicide Prevention Project in Finland and assessed the feasibility of the theoretical model for analyzing suicide prevention developed in earlier studies [ Upanne, 1999a , b ]. The study was formulated as a retrospective self-assessment where participants compared their earlier descriptions of suicide prevention with their current views. The changes in conceptions were analyzed and interpreted using both the model and the explanations given by the subjects themselves. The analysis proved the model to be a useful framework for revealing the essential features of prevention. The results showed that the freely-formulated ideas on prevention were more comprehensive than those evolved in practical work. Compared to the earlier findings, the conceptions among the group had shifted toward emphasizing a curative approach and the significance of individual risk factors. In particular, greater priority was focused on the acute suicide risk phase as a preventive target. Nonetheless, the overall structure of prevention ideology remained comprehensive and multifactorial, stressing multistage influencing. Promotive aims (protective factors) also remained part of the prevention paradigm. Practical working experiences enhanced the psychologists' sense of the difficulties of suicide prevention as well as their criticism and feeling of powerlessness.

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