Mass Transfer In Dispersed And Continous Phases For Creeping Flow Of Fluid Spheres Through Power Law Fluids

The diffusion equation was numerically solved by an implicit finite-difference method for the purpose of calculating the continuous phase Sherwood number, Sh, for mass transfer from an internally circulating Newtonian droplet traveling through a non-Newtonian power-law-type continuous phase in the creeping flow regime. The Mohan stream functions were used in the calculations in order to approximate the velocity profile inside and outside the droplet. The calculated Sh is presented as a function of the Peclet number, Pe, power-law index, n, and a viscosity ratio parameter, X. Sh increases as n decreases in the pseudoplastic region. The dependence of Sh on n is important when Pe is greater than 102, except when both X \u3e 1 and Pe \u3e 104. When used with the Mohan stream functions, the Baird and Hamielec short-range diffusion equation provides a close approximation for Sh when X \u3c 3, provided that Pe \u3e 104. The mass transfer model for the dispersed phase was also numerically solved in order to determine the effect of continuous phase pseudoplasticity, n. Although a slight increase in the total amount of mass transferred, Amt, with a decrease in n was determined, it is concluded that the power-law behavior in the continuous phase does not affect to any appreciable extent the internal mass transfer, either with or without chemical reaction in the fluid sphere. Amt increases with decreasing X, and this dependency is particularly important when mass transfer occurs with chemical reaction in the dispersed phase. © 1976, American Chemical Society. All rights reserved

Mass Transfer To Drops Moving Through Power Law Fluids In The Intermediate Reynolds Number Region

The mass transfer rate to fluid spheres is calculated for power law and Newtonian fluids by using the intermediate Reynolds number stream functions of Nakano and Tien (1970) and Yamaguchi et al. (1974), respectively. The Sh increases with increases in Re and Pe and decreases in n. Better results are obtained with Nakano and Tien\u27s functions when Re \u3e 10 and with Yamaguchi\u27s functions when Re \u3c 10. Copyright © 1976 American Institute of Chemical Engineer

Optimal location for eliciting the tibial H-reflex and motor response

INTRODUCTION: Although there are numerous protocols to adjust the amplitude of the Hoffmann reflex (H‐reflex) relative to the size of the direct motor response (M‐response), the optimal stimulating location has not been described. We sought to determine the optimal positioning of the stimulating cathode when evoking the tibial nerve H‐reflex and M‐response. METHODS: A small cathode was placed on defined points in the popliteal fossa while an anode was fixed on the patella. The tibial nerve was stimulated electrically, and the response of the soleus muscle was recorded using intramuscular and surface electromyography. RESULTS: We found that more‐lateral points along a line drawn across the popliteal fossa were the best locations to obtain only the M‐response, whereas stimulating the midpoint was optimal for obtaining only the H‐reflex. DISCUSSION: By using specified locations for electrical stimulation to evoke H‐reflex and M‐response, the functionality of the tibial nerve can be assessed. Muscle Nerve 58:828–833, 201

Is neck circumference measurement an indicator for abdominal obesity? A pilot study on Turkish Adults

Background: Neck circumference (NC) measurement is one of the simple screening measurements which can be used as an index of upper body fat distribution to identify obesity.Objectives: The aim of this study was to determine the relationship between neck circumferences and obesity.Methods:A total 411 volunteer adults participated in this study (174 men, 237 women). A questionnaire which consisted of anthropometric measurements and demographic features was used. Patients with NC ≥37 cm for men and ≥34 cm for women require evaluation of overweight status.Results: The percentages of the men and women with BMI ≥ 25kg/m2 were 55.2% and 27.0% respectively and with high neck circumferences were 85.1% and 38.8%, respectively. The percentages of the men and women with high waist circumference were 31.6% and 79.3%, respectively. In both gender there were positive significant correlations between neck circumference, body weight (men, r=0.576; women, r=0.702; p=0.000), waist circumferences (men, r=0.593; women r=0.667; p=0.000), hip circumferences (men, r=0.568; women, r=0.617; p=0.000) and BMI (men, r=0.587; women, r=0.688; p=0.000).Conclusions: This study indicates that NC was associated with body weight, BMI, waist and hip circumferences and waist/hip ratio for men and women. A significant association was found between NC and conventional overweight and obesity indexes. NC was associated with waist/hip ratio for men and women.Key words: Neck circumference, obesity