Edward Nashed Boulos

Absorption of iron and water in the Na2O–CaO–MgO–SiO2 glasses. I. Separation of ferrous and hydroxyl spectra in the near IR region

Abstract A number of 13Na2O–10CaO–6MgO–71SiO2 glasses doped with iron were melted in gas and electric furnaces using for batching both natural materials that are usually used in glass industry, and high purity chemicals. The concentration of Fe2O3 in the glasses was varied from 5×10−4 to 0.9 wt%. Absorption spectra of water and ferrous ions for the spectral region 3000–1000 nm (3300–10 000 cm−1) were separately determined from experimental absorption spectra and tabulated. An absorption band for the ferrous ion was observed in the region of 2985 nm (3350 cm−1) which, to our knowledge, has not been reported. A simple algorithm was developed to describe absorption of water and iron in each glass and to simulate the spectra in both pure and iron doped silicate glasses. Only two parameters are necessary for spectra simulation; both can be determined from experimental absorption spectra.

STATISTICAL PROCESS CONTROL BY THE QUOTIENT OF TWO CORRELATED NORMAL VARIABLES

The relationship between the composition and properties of glass has long been studied by glass scientists and technologists. The glass technologist in a production facility, faced with composition changes, must control the influence of these changes on..

Graded-index AR coatings for large angles of inclination

Abstract Antireflective coatings consisting of a single layer of glass with a graded variation in refractive index offer advantages over multi-layer coatings. These include a weaker dependence on angle of incidence at large angles and a flatter response to different wavelenghts over the visible. Consequently, graded-index films are desirable in automotive applications where colorless coatings are required. A sol-gel process is presented for the formation of a graded-index coating of MgOSiO 2 with in-diffused fluorine. Refractive index variations over a range 1.46-1.40 are achieved over a few hundred micrometers. A theoretical analysis of the angular and wavelength dependence of the reflectivity of uncoated, single-layer coated, triple-layer coated and graded-index-layer coated samples was performed and compared with experimentally derived films. Good agreement between model and experiment was observed.