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.

Numerical Investigation of Plasma-Based Flow Control for Transitional Highly-Loaded Low-Pressure Turbine

Abstract: Plasma-based active flow control was simulated numerically for the subsonic flow through a highly loaded low-pressure turbine. The configuration corresponded to previous experiments and computations which considered flow at a Reynolds number of 25,000 based upon axial chord and inlet conditions. In this situation, massive separation occurs on the suction surface of each blade due to uncovered turning. The present exploratory numerical study was performed to investigate the use of asymmetric dielectric-barrier-discharge actuators for mitigating separation, thereby decreasing turbine wake losses and increasing efficiency. Solutions were obtained for the Navier-Stokes equations, which were augmented by a phenomenological model that was used to represent plasma-induced body forces imparted by the actuator on the fluid. The numerical method used a high-fidelity time-implicit scheme, employing domain decomposition to carry out calculations on a parallel computing platform. A high-order overset grid approach preserved spatial accuracy in a locally refined embedded region. The magnitude of the plasma-induced body force required for control is examined, and both continuous and pulse-modulated actuations are considered. Novel use of counterflow actuation is also investigated, and the effects of pulsing frequency and duty cycle are considered. Features of the flowfields are described, and resultant solutions are compared with each other, with previous mass-injection control cases, and with the baseline situation where no control was enforced.

Textured magnetoplumbite fiber-matrix interphase derived from sol-gel fiber coatings

Abstract: A calcium hexaluminate (CaAl{sub 12}O{sub 19}, magnetoplumbite structure) sol was used to coat alumina and yttrium-aluminum-garnet (YAG) single-crystal fibers and single-crystal alumina plates. When the coated substrates were either annealed or hot-pressed in polycrystalline alumina and YAG matrices, the calcium hexaluminate basal cleavage planes were aligned parallel with the fiber-matrix interface. A complex series of reactions and phase transformations contributed to texture formation on alumina substrates. The alumina fibers and plates seeded the phase transformation of sol-derived transition aluminas to {alpha}-Al{sub 2}O{sub 3}, CaAl{sub 12}O{sub 19} and CaAl{sub 4}O{sub 7} formed between the seeded {alpha}-Al{sub 2}O{sub 3}, and CaAl{sub 4}O{sub 7} later reacted with the seeded {alpha}-Al{sub 2}O{sub 3} to form CaAl{sub 12}O{sub 19}, resulting in a single-phase coating. Several different mechanisms may be responsible for the texture. The microstructure, phase evolution, and possible mechanisms for texture formation of CaAl{sub 12}O{sub 19} powders, sol-derived thin films, and coated plates and fibers, with and without hot-pressed matrices, were studied and are discussed. Deflection and propagation of cracks within the fiber-matrix interphase in thin foils suggests that such an interphase may protect fibers from matrix cracks.

The Effect of Moderate Changes in Blood Volume on Left and Right Atrial Pressures

Abstract: The blood volume of 15 dogs was progressively increased an estimated 30 per cent by repeated blood infusions and decreased 30 per cent by stepwise hemorrhage. The pressures in the venous system, both atria and the pulmonary artery, rose and fell in unison with these moderate changes in blood volume and the new levels remained stable for at least 10 to 20 minutes. Although the right ventricle anatomically separates the systemic venous bed from the pulmonary circulation, small hemorrhages and transfusions have so little effect on its activity that, from the point of view of pressure volume relationships, the systemic veins and the left atrium are parts of the same functional unit.

Inkjet and Aerosol Jet Printing of Electrochemical Devices for Energy Conversion and Storage

Abstract: Inkjet and aerosol jet printing have recently emerged as promising fabrication techniques for a broad range of devices for electrochemical energy conversion and storage – batteries, fuel cells, and supercapacitors. If fully realized, these printing techniques may enable device performance advantages accruing from precise micron scale patterning, thin layer deposition, and materials grading. Printing may also allow scalable, low materials waste manufacturing, and conformal integration of power elements into structural elements. This article reviews the fundamental capabilities of inkjet and aerosol jet printing relevant to electrochemical devices, surveys current literature, and presents future challenges which must be tackled to achieve high performance, printed electrochemical energy storage, and conversion devices.

Wartime decompressive craniectomy: technique and lessons learned.

Abstract: Object Decompressive craniectomy (DC) with dural expansion is a life-saving neurosurgical procedure performed for recalcitrant intracranial hypertension due to trauma, stroke, and a multitude of other etiologies. Illustratively, we describe technique and lessons learned using DC for battlefield trauma. Methods Neurosurgical operative logs from service (October 2007 to September 2009) in Afghanistan that detail DC cases for trauma were analyzed. Illustrative examples of frontotemporoparietal and bifrontal DC that depict battlefield experience performing these procedures are presented with attention drawn to the L.G. Kempe hemispherectomy incision, brainstem decompression techniques, and dural onlay substitutes. Results Ninety craniotomies were performed for trauma over the time period analyzed. Of these, 28 (31%) were DCs. Of the 28 DCs, 24 (86%) were frontotemporoparietal DCs, 7 (25%) were bifrontal DCs, and 2 (7%) were suboccipital DCs. Decompressive craniectomies were performed for 19 penetrating head i...