Functionalization of Surfaces with Optical Coatings Produced by PVD Magnetron Sputtering

This chapter describes the functionalization of the surface of the glass through thin film inorganic coatings. Such filters called dichroic filters, following the physical principle of interference of light using the rules of optical physics. The design of the optical multilayer materials with high and low refractive index and optimizing the predetermined optical responses. The AFM quantify the real thickness and, calibrate the deposition plant, using as an input data for the simulation to evaluate the dispersion index refraction and absorption. The dichroic filters separate the incident radiation into two or more predetermined optical bands. The materials used are deposited using PVD Reactive Magnetron Sputtering, allows to increase the deposition rate, to obtain good homogeneity range of the surface deposited. The set point of deposition which allows to obtain stoichiometric oxides is analyzed with the technique RBS. These optical filters, also called dichroic are applied in the research field of the splitting photovoltaic concentration.

The thickness of laminar flames in pre-mixed reactants: optical considerations

The concept of flame thickness and the necessary criteria for its definition and measurement are briefly discussed. Owing to ray deflexions occasioned by the flames’ refractive index fields, the apparent thicknesses of luminous zones are always in part optical illusion. Expres­sions in terms of burning velocity, flame geometry and physical properties of the reactants are derived for the apparent thickness of an idealized luminous zone of no real thickness and numerical values are deduced for typical flames used in combustion research. Their similarity to measured values leads to the conclusion that, at normal pressures, such measurements do not, in general, furnish a true measure of luminous flame thickness. The second part deals with the examination of flame by extraneous light. Simple optical methods of measuring flame thickness according to various definitions are presented, their theory is discussed and their use is illustrated by sample results.

Sedimentary Formations of Abnormal Thickness

For many years past the writer of the present note has devoted much thought to the problem of the origin of sedimentary series of enormous thickness, such as occur or are said to occur in many parts of the world. In one group of instances the answer is easy: that the great thickness is apparent and not real. Such for example are some types of delta deposit, where the material has been laid down on a submarine slope in a manner analogous to the formation of a railway embankment or a slag heap, by tipping trucks over the end. Here obviously the total attained by adding together the thicknesses of all the inclined layers is quite misleading. This effect may be seen in the foreset beds of almost any deltaic deposit on almost all scales, and its true nature is generally revealed by the occurrence of topset or bottomset, more or less horizontal beds above or below. This effect is very well seen on the south coast of Devon westwards from the mouth of the Exe, where for some miles the bright red New Red Sandstone strata, usually considered to be Permian, dip consistently eastwards at 25 or 30 degrees. The conditions of formation of these brilliantly red strata are obscure, but in one railway cutting at the eastern end an obvious horizontal topset bed proves clearly that the dip is deceptive, and that the real thickness at that point need not be much more than the small depth of the cutting.