Ground water is the major source of freshwater on the earth. Groundwater containing dissolved ions beyond the permissible limit is harmful and not suitable for domestic use. Fluoride beyond desirable amounts (0.6 to 1.5mg/l) in groundwater is a major problem in many parts of the world. The fluorides belong to the halogen group of minerals and are natural constituents of the environment. Fluorid...

An approach to modeling the material removal rate (MRR) during rotary ultrasonic machining (RUM) of ceramics is proposed and applied to predicting the MRR for the case of magnesia stabilized zirconia. The model, a first attempt at predicting the MRR in RUM, is based on the assumption that brittle fracture is the primary mechanism of material removal. To justify this assumption, a model paramete...

We have used electron backscattered diffraction patterns to determine the misorientation of 201 adjacent pairs of grains in a magnesia polycrystal. The width and depth of the thermal grooves formed by these same grain boundaries were also measured by atomic force microscopy (AFM). By simulating the errors associated with the AFM observations and comparing our observations to existing data for m...

in this study, slag penetration into a magnesia refractory monolithic was investigated by the crucible test method. a synthetic calcium aluminate slag system has been used to study commercial magnesia mix refractory for 1, 2, 3, 4, 5 and 6 hours at 1450°c and 1600°c. it has been shown that the penetration rate is controlled by a diffusion mechanism at 1450°c. in this case, capillaries are the ...

The magnesia (MgO) hydroxylation behavior in dilute suspensions (below 50% volumetric solid loads) has been extensively studied over the past decades due to its role refractory castables. However, equivalent effects on concentrated systems have not analyzed such a systemic way, although they are known be as or more deleterious than those observed systems. This study focuses of different sources...

  ABSTRACT Dolomite refractories have a good production potential in Iran due to the existence of high-quality dolomite ore in many regions of the country, particularly in Isfahan and Hamedan. The basic problem associated with the production and use of this type of refractories is inherent tendency to hydration of calcined dolomite. One of the methods to overcome this problem is to increase the...

Inelastic electron tunneling spectroscopy (IETS) is a unique surface and interface analytical technique using electron tunneling through a metal/insulator/metal tunneling junction at cryogenic temperatures. It gives the vibrational spectrum of a very thin (nm) insulator film and the adsorbed species on it. The high sensitivity, good resolution, and wide spectral range inherent in IETS enable us...