Introduction to life modeling of thermal barrier coatings

Thermal barrier coatings may be applied to air-cooled turbine section airfoils to insulate such components from hot gases in the engine. The coatings, which typically consist of about 0.01 to 0.04 cm of zirconia-yttria ceramic over about 0.01 cm of NiCrAlY or NiCrAlZr alloy bond coat, allow increased gas temperatures or reduced cooling air flows. This, in turn, leads to marked improvements in engine efficiency and performance. However, certain risks are associated with designing for maximum benefits, and eventually a point is reached where coating loss would immediately jeopardize the underlying component. Therefore, designers must be able to accurately predict the life of a given bill-of-material coating in any particular design. The results of an in-house aeronautics, base research and technology program which is designed to provide the first steps towards developing mission-capable life-prediction models are outlined

Reliable low-cost battery voltage indicator for light aircraft and automobiles

Voltage indicator fits into cigarette lighter socket and utilizes light emitting and Zener diodes to display three levels of battery voltage. Indicator is superior to typical conventional electrical system indicators in that it gives a positive discrete indication of battery voltage. It is simple, inexpensive, and rugged

RETSCP-A computer program for analysis of rocket engine thermal strains with cyclic plasticity

Finite element program employs three-dimensional isoparametric element for analysis of rocket engine thermal strains with cyclic plasticity

Remote measurements by telephone

Inexpensive device permits measurement and remote interrogation of variables such as voltage, temperature, pressure, or humidity by standard telephone equipment. Remote interrogation of wind direction and velocity, humidity, or water levels on flood-prone river are other possible representative uses for this device

Identification of the Pink Hibiscus Mealybug, Maconellicoccus hirsutus (Green) (Hemiptera: Sternorrhyncha: Pseudococcidae)

The pink hibiscus mealybug, Maconellicoccus hirsutus (Green), has spread rapidly in the tropical and subtropical areas of the New World especially throughout the Caribbean Islands, and has rece~t1y been discovered in California, Mexico, and Belize. All instal's of the pink hibiscus mealybug are descrIbed and illustrated to facilitate discovery of infestations. Comparisons with other common pest species are provided for most of the 8 instars, and a table is included that distinguishes the pink hibiscus mealybug from other pest species in the field

Passive zero-gravity leg restraint

A passive zero or microgravity leg restraint is described which includes a central support post with a top and a bottom. Extending from the central support post are a calf pad tab, to which calf pad is attached, and a foot pad tab, to which foot tab is attached. Also extending from central support post are knee pads. When the restraint is in use the user's legs are forced between pads by a user imposed scissors action of the legs. The user's body is then supported in a zero or microgravity neutral body posture by the leg restraint. The calf pad has semi-ridig elastic padding material covering structural stiffener. The foot pad has padding material and a structural stiffener. Knee pads have s structural tube stiffener at their core