Effect of nanoparticles on heat transfer in heat exchangers

In this paper, forced convection flow and heat transfer of a Al2O3/Water nanofluid have beeninvestigated numerically by single and two phase (volume of fluid) models. Nanofluid flows inside the innertube of the isothermally concentric circular and sinusoidal double tube heat exchangers while hot pure waterflows in the outer tube. The single-phase and two-phase models is used to simulate the nanofluid forcedconvection of 2% and 3% volume concentrations. The renormalization group k-ε model is used to simulateturbulence in ANSYS FLUENT 15.0. Results show that the overall heat transfer coefficient increases withnanoparticle volume concentrations in the heat exchangers. The highest overall heat transfer coefficient rates aredetected, for each concentration and shape, corresponding to the highest flow rate for the sinusoidal tube heatexchanger . The maximum overall heat transfer coefficient enhancement is 220% for the particle volumeconcentration of 3% at the inner tube of concentric sinusoidal double tube heat exchanger corresponding to flowrate =10 LPM. The results reveal that the Al2O3/water pressure drop along the inner tube of circular andsinusoidal double tube heat exchanger increases by about 3% and 5% for volume concentrations of 2% and 3%,respectively, given flow rate compared to the base fluid.Comparison of these results with Rohit S. Khedkar‘spublished experimental data, showed good agreement

Methanol Poisoning as a Trigger for the Presentation of Diabetes Mellitus: A Case Report

Background: The clinical and laboratory manifestations of methanol poisoning and Diabetic Ketoacidosis (DKA) might be very similar.Case Presentation: A 15-year-old male, who lived in Mashhad, Iran, was referred to a medical toxicology center because of the loss of consciousness following the consumption of home-made alcohol. Laboratory tests revealed metabolic acidosis, the high blood levels of methanol, and ketonuria and glucosuria in urine analysis. The treatment of DKA and methanol poisoning was started simultaneously.Conclusion: Methanol poisoning, as physical stress or because of pancreatitis as a complication, could be a trigger for diabetes in susceptible individuals, and physicians should be aware of the similarity of presentation of these situations.

Brooke-Spiegler Syndrome

The Brooke-Spiegler syndrome (BSS) is an uncommon autosomal dominant disorder characterized by a high affinity to form multiple adnexal neoplasia (skin appendage tumors), especially trichoepitheliomas and cylindromas, and occasionally spiradenomas, which usually appear in the second or third decade of life. To date, only a few cases with this syndrome have been reported. This case report describes a 26-year-old woman who presented to the dermatology department of Qaem Hospital with tumoral lesions on her scalp, face, and forearm. Her father and younger brother were also affected. On examination, several round-to-oval skin-colored papules with a smooth pearly surface measuring 2 to 6 mm in diameter were seen on the mid-face, particularly in the nasolabial folds, the upper lip. Tumors and nodules seen on the scalp were pinkish red, dome-shaped, and to some extent, pedunculated with surface telangiectasia and induration. Histopathology of the facial papules showed trichoepithelioma while that of a scalp nodule showed cylindroma