Starved area

The International Atomic Energy Agency was formed in 1957 with a first mission focused on safeguards, and other missions expressed by President Eisenhower in his famous address about atoms for peace before the United Nations three years before apply atomic energy to the needs of agriculture, medicine and other peaceful activities and provide abundant electrical energy in the power-starved areas of the world . 

Fig. 12.26. Since the availability of oxygen varies on a metal, metal dissolution takes place at oxygen-starved areas.

Another important factor with regard to adherends is the uniformity and tolerances allowed in the joint fit-up. Improper tolerances on the geometry of the joint can lead to adhesive-starved areas or areas where the bond is so thick that unwanted peel and cleavage forces can easily develop. 

This process also called just bag molding. It is the conventional hand lay-up or spray-up that is allowed to cure without the use of external pressure. For many applications this is sufficient, but maximum consolidation may not be reached. There can be some porosity fibers may not fit closely into internal corners with sharp radii but tend to spring back. Resin-rich and/or resin-starved areas may occur because of draining, even with thixotropic agents. With moderate pressure (hand rollers, etc.) these defects or limitations can be overcome with significant improvement in mechanical properties. 

The scope of this discussion will be limited to those spectroscopic applications where low light levels are involved. It is in these applications where most of the problems occur, and where an in-depth knowledge of detector performance is required in selecting a detector for a particular application. By definition, in this category are included all "photon-starved" areas of spectrometry. It is instructive to consider some of the causes of photon starvation in spectroscopy. 

Dicy is soluble in 2-methoxyethanol, DMF and an acetone/H20 mix. In solventless systems, pulverized dicy is used, which is well dispersed into the resin system using either a ball or a 3-roll mill. If the dicy is in suspension in a prepreg system and the particle size is too great, it is possible that the carbon fiber reinforcement will filter the dicy out from the resin matrix, producing dicy starved areas, and result in a partial cure. Dicy can be dissolved prior to use by a technique called spiking, when the dicy/resin mix is held at 120°C for one hour. If lower temperatures are used, say 65°C, the dicy becomes encapsulated within the resin and subsequent heating at 120°C will not allow the dicy to diffuse into the resin, resulting in a product with a Tg some 50° C lower. 

Resin-starved area (dry spot) n. An area of a reinforced-plastic article that has an insufficient amount of resin to wet out the reinforcement completely, evidenced by low gloss, dry spots, or exposure of fiber. The condition may be caused by improper wetting or impregnation, or by excessive molding pressure. 

Differential aeration cells can be caused by crevices, lap joints, dirt and debris, and moist insulation. Under these conditions, the oxygen starved areas are anodic, while the areas with free access to oxygen are cathodic. Common terms for this type of corrosion include crevice corrosion, oxygen screening, and poultice action. 

The handling and reliability advantages of tape and film adhesive include that they are ready to use, and there is no need for mixing, no degassing, and no possibility for error in adding catalyst. Tapes permit a variety of lay-up techniques, which facilitate the production of virtually defect-free structures. The use of a mesh support helps to control the bond-line thickness with tape adhesives, avoiding thin, adhesive-starved areas where curvature or external pressure is the greatest. 

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