Variable characteristics of viscosity and thermal conductivity in peristalsis of magneto-Carreau nanoliquid with heat transfer irreversibilities.

BACKGROUND: Peristaltic is a basic way of fluid transportation in physiology, engineering and nuclear industry. Importance of peristalsis is due to its contraction and compulsion property of symmetric and asymmetric type channel walls. Another beauty of this mechanism is that the channel walls propagates and push the material along the tube/conduit channel walls. This mechanism shows its presence in physiology while food particles are transferred through esophagus and stomach, urine through intestines, spermatoza transportation in reproductive tract. In industry it is found in roller and finger pumps, drug delivery and various nuclear materials e.g. toxic, corrosive, noxious etc. Magnetic field in peristalsis is found helpful in treatment of various treatments using magnets. Actually earth and human body as a whole comprises of magnetic and electric fields. The medical specialists found that unbalances of electromagnetic field in human body is the reason for emotional and physical disturbance. In addition it has significant and potential utilizations in modification of medical, industrial and chemical, procedures for example MRI, evaporation, convection, thermoregulation, MHD throttles, and in various types of tumor treatments. Entropy production work out irreversibility in complex systems which are frequently encountered in industrial mechanisms. In view of that, this methodology is effectually implemented in distinct technological applications covering porous media, propulsion ducts, electronic cooling, turbo-machinery and combustion. METHOD: Modelled flow mechanism is nonlinear and coupled due to considered assumptions (i.e. nanofluid, nonlinear porous channel, mixed convection, variable viscosity and thermal conductivity, activation energy and chemical reaction). Such nonlinear and coupled system is difficult to tackle analytically. Thus to obtain the solution we employed RK algorithm for numerical simulations. RESULTS: Stronger magnetic parameter shows resistive characteristics to the flow field. Nonlinear Darcy medium assists the fluid motion at channel center and resits at walls vicinity. Variable characteristics of thermal conductivity moderate the soak or disperse up heat ability which corresponds to temperature reduction. Thermal slip quantity increase the temperature whereas concentration slip deduct the concentration of Carreau nanomaterial. Entropy and Bejan number shows maximum response for higher dissipation estimations. Brownian and thermopherotic motions aspects has reverse impact on nanomaterial concentration. CONCLUSION: Entropy and Bejan number deduces for higher variable thermal conductivity values. Carreau material variable enhance the entropy of the system as a whole.

Effects of acacia honey on wound healing in various rat models.

Honey is a traditional remedy for the treatment of infected wounds, and is becoming more important as microbial resistance to conventional therapeutic agents increases. A study was conducted to assess the wound-healing activity of Acacia honey using incision, excision, burn and dead-space wound models in rats. Different formulations of honey were used and rats were treated topically as well as orally. Both the higher and lower doses of honey produced a significant effect on healing (p < 0.05). The area of epithelization was found to increase, followed by an increase in wound contraction, skin-breaking strength, tissue granulation. The hydroxyproline content also increased in the rats treated with higher doses of honey compared to control, indicating an increase in collagen formation.

Effect of left atrial size on recurrence of atrial fibrillation after electrical cardioversion: atrial dimension versus volume.

UNLABELLED: There are conflicting reports on the relationship between left atrial dimension (LAD) determined by echo-cardiography and the incidence of atrial fibrillation (AF) recurrence after electrical cardioversion (EC). We hypothesized that left atrial volume (LAV) by echocardiography might better differentiate patients who will have recurrence of AF after EC. METHODS: Forty-one patients having EC for AF were prospectively studied by echocardiography. LAD was measured by American Society of Echocardiography guidelines as the anterior-posterior dimension in the parasternal view. LAV was measured by Simpson's method using an off-line analysis system and reported as the average of values from the apical four-chamber and two-chamber views. RESULTS: (Data are mean +/- SEM): Patient follow-up was 15 +/- 10 months. No cutoff value of LAV predicted AF recurrence, but all three patients with LAD greater than 65 mm had AF recurrence. Compared with patients maintaining normal sinus rhythm (NSR) (N = 18), the AF group (N = 23) had a lower percentage of antiarrhythmic drug use, especially type IA agents (p < .02). Patients who stayed in NSR tended to have shorter AF duration before EC (16 +/- 15 v 63 +/- 122 weeks, p = .08) but did not differ in age (53 +/- 27 v 58 +/- 23 years), LAD (51.1 +/- 7.7 v 54.2 +/- 9.4 mm) or LAV (85.1 +/- 24.3 v 95.1 +/- 33.3 mL). CONCLUSIONS: (1) LAV by echocardiography does not improve identification of patients at risk for recurrence of AF after EC, (2) patients with LAD up to 65 mm may maintain NSR after EC, (3) LAD greater than 65 mm is associated with AF recurrence, and (4) use of antiarrhythmic drugs and the duration of AF before EC may be better predictors of maintenance of NSR than echocardiographic measures of left atrial parameters.