Wright-Patterson Air Force Base

About: Wright-Patterson Air Force Base is a other organization based out in Wright-Patterson AFB, Ohio, United States. It is known for research contribution in the topics: Laser & Mach number. The organization has 5817 authors who have published 9157 publications receiving 292559 citations. The organization is also known as: Wright-Patterson AFB & FFO.

The mechanical impedance of the human body in sitting and standing position at low frequencies.

Abstract: The theory of the mechanical impedance of systems with one or more degrees of freedom is applied to the human body. A method of measuring mechanical impedance and determining the parameters of the vibrating systems is developed. Impedance curves for longitudinal vibrations of a sitting and standing subject are established for the frequency range of 1 to 20 c/s. The influence of varied posture and restraining systems is investigated. Dynamic movements of body parts are measured, directly or indirectly, and compared with the impedance curves. The responsible elements in the body for the apparent resonances are identified. Correlations between the impedance function of the body and the subjective tolerance curve to vibration are found and the reasons for the tolerance limits are elucidated. The variability of subjective tolerances due to varying posture, restraining systems, cushions, duration of exposure and vibrations are discussed, and conclusions for the development of protective devices are drawn. The c...

Preparation of High-Purity Submicron Barium Titanate Powders

Abstract: Simultaneous hydrolytic decomposition of barium bis isopropoxide and titanium tetrakis tertiary amyloxide was used to produce stoichiometric BaTiO3. The particle size range was 50 to 150 A. The purity was 99.98+%, the major contaminant being silicon from the glass apparatus. The homogeneity and stoichiometry of the powder were demonstrated by electron microscopy and wet chemical analysis. X-ray and infrared analyses indicate that the material, as-prepared and helium-dried at 5O°C, has the titanate crystal structure. The powder sinters at 1300°C to a high density, translucent body with a uniform microstructure. The experiments suggest that the alkoxy-based preparation of oxides may provide a broad base for improving the quality and reproducibility of electrical and structural ceramics.