Nicotine stomatitis and its relation to carcinoma of the hard palate in reverse smokers of chuttas

Clinical surveys and biopsy studies demonstrated a close correlation among reverse smoking, nicotine stomatitis, and carcinoma of the palate

Density Marching Method for Drawing Phase Envelopes. 3. <i>P‑xy</i> Diagrams of Binary Mixtures

Some of the most widely used commercial process simulators and property programs cannot calculate <i>P-xy</i> diagrams of even simple binary mixtures satisfactorily when the specified temperature is greater than the critical temperature of one of the two components because of the limitations of the methods used by them currently. In this paper, we present a new method for drawing <i>P-xy</i> diagrams of binary mixtures that overcomes the limitations of the present methods. In the proposed method, the density of the vapor/liquid phase is varied systematically and the saturation point calculated at each of the specified density (instead of the conventional specified concentration) to generate <i>P-xy</i> diagrams. Two different approaches have been presented for the calculation of saturation points at specified density. The methods presented are an extension of the density marching method presented earlier for drawing two-phase and three-phase isopleths. A number of zeotropic and azeotropic mixture examples are presented to demonstrate the methods

An Analysis of Coupled PEM Fuel Cell - Metal Hydride Hydrogen Storage Tank System

Abstract Thermal coupling of PEM fuel cells (PEMFC) and metal hydride hydrogen storage tanks is an interesting possibility. While, hydrogen desorption from metal hydrides is an endothermic process, the fuel cell generates considerable amount of waste heat to be rejected. Hence one can visualize a self-sustainable system by utilizing the fuel cell heat output at the metal hydride storage device for hydrogen desorption. Moreover, the metal hydride device can also act as a thermal compressor to deliver hydrogen at higher pressures which can improve the performance of the fuel cell. Due to the difference between the rates of desorption of hydrogen from the metal hydride bed and consumption of hydrogen in the fuel cell, an interface between the two components needs to be introduced. In the case studied in this paper, the interface is a gas buffer tank together with a control valve to deliver hydrogen at preset pressure and varying flow rate as demanded by the fuel cell. Such a system has been analyzed for different operating conditions and load requirements