CONCAVE–  Hollowed or rounded inward like the inside of a bowl. CONTAMINANTS–  Substances  that  contaminant other  substances. CONVEX–  Curving  outward  like  the  surface  of  a sphere. COUNTERSINK–  To set the head of a screw at or below the surface. CRES– Comosion-resistant   steel. CRYSTALLINE– Composed  of  crystals. CYLINDRICAL–  Relating to or having the form or properties of a cylinder. DEAERATE– To remove air or gas from. DECONTAMINATE– To rid of contamination. DESICCANT– A drying agent. DETERIORATION– The act or process of becoming impaired in quality, functioning, or conditioning. DYNAMIC  SEAL–   Seal  between  two  parts  with relative  motion. ELECTROHYDRAULIC–  A  combination  of  electric and  hydraulic  mechanisms. ELONGATED–  Stretched  out. EMULSION– A suspension of small globules of one liquid in a second liquid with which the first will not mix, such as milk fats in milk. EPOXY–  A compound in which an oxygen atom is joined  to  each  of  two  attached  atoms,  usually carbon.   Designation   of   various   thermosetting resins,  containing  epoxy  groups,  that  are  blended with   other   chemicals   to   form   strong,   hard, chemically  resistant  substances,  such  as  adhesives, paints, etc. ERRATIC– Deviating  from  the  normal,  conventional, or customary course. EUTECTIC–  Mixture or alloy with a melting point lower than that of any other combination of the same components. EXTRUDED–  To push or force out, expel. To force (metal, plastic, etc.) through a die or very small holes to give it a certain shape. FERROUS– Substances  containing  iron. FIBER– A single strand of material that is rolled or formed in one direction, and used as a principal constituent in composite material because of its high axial strength and modulus. FUSIBLE– Liquified  by  heat,  easily  melted. GALLING– Chafing. GPM– Gallons per minute. HALOGEN–  Any of the five elements  fluorine,  chlorine, iodine. nonmetallic   chemical bromine,  astatine,  and HELICAL–  Something  spiral  in  shape. HONEYCOMB– A strong, lightweight, cellular struc- tural  material. HP– Horsepower. HYDRAULICALLY–   Operated  by  the  resistance offered  or  by  the  pressure  transmitted  when  a quantity  of  liquid,  such  water  or  oil,  is  forced through a small orifice or tube. HYDROCARBON– An  organic  compound  containing only carbon and hydrogen and often occurring in petroleum, natural gas, coal and bitumens. HYDROCHLORIC ACID– A strong, highly corrosive acid that is a water solution of the gas hydrogen chloride, and is widely used in the processing of ore and for cleaning metals. HYDROLYZE– To decompose a compound by split- ting it into other compounds by taking up water. IMBEDDED– To make something an integral part of. IMPREGNATED–   To  furnish  one  substance  with some  actuating  or  modifying  substance  that  is infused or introduced. An example is the nonwoven, non- metallic, abrasive mats that are used for the removal of corrosion products and paint scuffing prior to painting. These abrasive mats are, in effect, nylon  webbing,  impregnated  with  aluminum  oxide. INERT– Lacking a usual or anticipated chemical or biological  action. INHIBITOR–  An agent that slows or interferes with a chemical  reaction. INTEGRAL FUEL CELL–  A  structural  configuration in which a component of the aircraft serves as a fuel container. KEVLAR®– tough, light, aramid synthetic fiber used in making bulletproof vests, boat hulls, airplane parts, etc. AI-2