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 & Microstructure. The organization has 5817 authors who have published 9157 publications receiving 292559 citations. The organization is also known as: Wright-Patterson AFB & FFO.

Random laser action in organic–inorganic nanocomposites

Abstract: Random laser action is demonstrated in organic–inorganic, disordered hybrid materials consisting of ZnO semiconductor nanoparticles dispersed in an optically inert polymer matrix. The ZnO particles provide both the gain and the strong scattering power that leads to light trapping due to multiple elastic scattering, whereas the polymer matrix offers ease of material fabrication and processability in view of potential applications. Excitation of the nanohybrids by a laser pulse with duration shorter than the ZnO photoluminescence lifetime leads to a dramatic increase in the emitted light intensity accompanied by a significant spectral and temporal narrowing above a certain threshold of the excitation energy density. Critical laser and material parameters that influence the observed laser-like emission behavior are investigated in a series of nanocomposites.

The effect of matrix to reinforcement particle size ratio (PSR) on the microstructure and mechanical properties of a P/M processed AlCuMn/SiCp MMC

Abstract: Matrix to reinforcement particle size ratio (PSR) is the main factor governing the homogeneity of the reinforcement particle distribution in composites manufactured by the powder metallurgy route. To improve the homogeneity of the distribution, reinforcements with larger average particle size should be used. At the same time, increasing the reinforcement particle size leads to worsening of the mechanical properties due to lower work hardening and higher damage accumulation rates. It is therefore important to optimize the microstructure somewhere in between a smaller reinforcement particle size and a more homogeneous spatial distribution. The effect of PSR on the reinforcement spatial distribution, fabricability, and resulting mechanical properties of a P/M processed AlCuMn/SiC/15p composite was investigated. It was shown that increasing the PSR results in a less-uniform reinforcement distribution, which in turn leads to a decrease in the material fabricability and a general worsening of the mechanical properties. A close to linear dependence of the mechanical properties (yield stress, UTS, elongation before fracture, Young’s modulus) on PSR was found. Tensile elongation shows the highest sensitivity to the worsening of the homogeneity of the reinforcement spatial distribution caused by increasing the PSR. The effect of microstructural homogeneity on the relative change of mechanical properties does not seem to depend on matrix alloy plasticity.

Mobility assist for the paralyzed, amputeed and spastic person

Abstract: Apparatus to actively assist neuromotor disabled to have better leg functional control/use This system serves as a strength enhancer, support device, and attenuator of spastic motions The disclosed orthosis is worn on the outside of the leg (or legs) and serves as an active/dynamic brace to prevent leg spasms and other untoward leg motion It is made of lightweight material such as fiberglass or aluminum and is actuated by pneumatic gas sources which are small, portable, and carried with the device The device is totally self contained and has no external connection The system has applicability to patients such as: stroke (cerebral vascular accident), TBI (traumatic brain injury), Muscular Dystrophy, and some spinal cord injured

Development of Hydrocarbon-Fueled Scramjet Engines: The Hypersonic Technology (HyTech) Program

Abstract: The Hypersonic Technology (HyTech) program was initiated in 1995 to maintain a core competency in hypersonictechnologiesafterthecancellation of theNationalAerospacePlaneprogram.HyTech isfocusedon expanding the technology base for liquid-hydrocarbon-fueled scramjet propulsion systems and is complementary in many ways to similar hydrogen-fueled hypersonic programs, such as Hyper-X. The overall effort consists of government sponsored industry efforts and an in-house technology base program. The technical challenges of these efforts associated with successful scramjet operation are addressed, which include activity in inlet/isolator operation, combustor operation and stability, nozzle operation, material advancement, fuel system development and integration and operability. The program has positively demonstrated the technologies that are critical to successful scramjet operation. The current status of work in each of these areas is discussed, followed by a discussion of upcoming activities for the program.

Radiation effects on osteoblasts in vitro: a potential role in osteoradionecrosis.

Abstract: Objective To evaluate the factors involved in bone remodeling and wound healing that may be altered by radiation therapy. Design A prospective, controlled study of biochemical activity in vitro. Subjects MC3T3-E1 mouse osteoblasts. Interventions Cells were irradiated at 0, 2, 4, or 6 Gy. Specimens were harvested at 1, 7, 14, 28, and 42 days following irradiation for immunohistochemical analysis of transforming growth factor β 1 expression and transforming growth factor β 1 type I and II receptor expression. Collagen production was measured at 1, 7, 28, 35, and 49 days after irradiation. The effects of dexamethasone on collagen production and cell proliferation were also examined. Results Irradiated cells demonstrated decreased cell proliferation and a dose-dependent, sustained reduction in collagen production when compared with control cells. An increase in transforming growth factor β 1 type I and II receptor expression was noted in irradiated cells when compared with controls. Conclusion Radiation-induced alterations of factors related to bone remodeling and wound healing have a potential role in the pathogenesis of osteoradionecrosis.