Joining techniques for fabrication of composite air-cooled turbine blades and vanes

Activated diffusion brazing studies of joining methods for composite air-cooled turbine blade and vane fabricatio

Investigations of the potential performance characteristics of selected contact lubricants for applications in miniature slip-ring capsules of the type used in ST 124 M stabilized inertial guidance platforms Final technical report, 27 Mar. 1968 - 30 Apr. 1970

Performance characteristics of liquid and solid lubricants for contacts of miniature slip-ring capsule

Protein-mediated DNA Loop Formation and Breakdown in a Fluctuating Environment

Living cells provide a fluctuating, out-of-equilibrium environment in which genes must coordinate cellular function. DNA looping, which is a common means of regulating transcription, is very much a stochastic process; the loops arise from the thermal motion of the DNA and other fluctuations of the cellular environment. We present single-molecule measurements of DNA loop formation and breakdown when an artificial fluctuating force, applied to mimic a fluctuating cellular environment, is imposed on the DNA. We show that loop formation is greatly enhanced in the presence of noise of only a fraction of $k_B T$, yet find that hypothetical regulatory schemes that employ mechanical tension in the DNA--as a sensitive switch to control transcription--can be surprisingly robust due to a fortuitous cancellation of noise effects

Bromoform emission over the Antarctic sea ice

Bromoform is one of the volatile organic compounds emitted from the ocean surface to the atmosphere, and it is believed to affect ozone depletion in the atmosphere through photochemical reactions. While estimates of air−sea flux of bromoform are well examined in open ocean areas, fluxes have rarely been estimated in ice-covered seas, and so far, no observations have been made to evaluate the bromoform flux between the sea ice surface and atmosphere. Here, we present the first direct measurements of the air−sea ice bromoform flux obtained from first-year sea ice off east Antarctica. Measurements were made in early austral spring (September to November 2012) as part of the Sea Ice Physics and Ecosystem Experiment II (SIPEX-2). Vertical profiles of bromoform concentrations in snow and sea ice indicated that high concentrations were mainly found in the bottom of the snow and the surface layers of the sea ice (Figure 1) (including slush and brine) ranging from 281−1360 pM. Sea ice–atmosphere bromoform fluxes measured by the chamber method ranged from +0.3 to +7.5 nmol CHBr3 m–2 day–1 (positive value indicates the emission of the bromoform from ice surface to the atmosphere), and flux values increased with increasing bromoform concentrations at the surface layers (Figure 2). The mean flux estimate (+2.4 nmol CHBr3 m–2 day–1) obtained in this study was consistent with the flux estimate for the ice-free part of the Southern Ocean (+2.6 nmol CHBr3 m–2 day–1; Quack and Wallace, 2003). Our results suggest that the bromoform emitted from the sea ice surface to the atmosphere may account for an important fraction of the global bromine budget.第4回極域科学シンポジウム個別セッション：[OM] 気水圏11月14日（木） 統計数理研究所 ３階セミナー室１（D305

Development of a chromium-thoria alloy

Low temperature ductility and high temperature strength of pure chromium and chromium-thoria alloy prepared from vapor deposited powder

Hydrodynamic Coupling of Two Brownian Spheres to a Planar Surface

We describe direct imaging measurements of the collective and relative diffusion of two colloidal spheres near a flat plate. The bounding surface modifies the spheres' dynamics, even at separations of tens of radii. This behavior is captured by a stokeslet analysis of fluid flow driven by the spheres' and wall's no-slip boundary conditions. In particular, this analysis reveals surprising asymmetry in the normal modes for pair diffusion near a flat surface.Comment: 4 pages, 4 figure

Mechanical properties and LOX compatibility of stainless steel-clad titanium prepared by explosive welding and vacuum deposition Final report

Tensile and fatigue properties and liquid oxygen compatibility of bilaminate stainless steel-clad titanium prepared by vacuum deposition and explosive weldin

Development of gas-pressure bonding process for air-cooled turbine blades

An investigation was conducted on the application of gas-pressure bonding to the joining of components for convectively cooled turbine blades and vanes. A processing procedure was established for joining the fins of Udimet 700 and TD NiCr sheet metal airfoil shells to cast B1900 struts without the use of internal support tooling. Alternative methods employing support tooling were investigated. Testing procedures were developed and employed to determine shear strengths and internal burst pressures of flat and cylindrical bonded finned shell configurations at room temperature and 1750 F. Strength values were determined parallel and transverse to the cooling fin direction. The effect of thermal cycles from 1750 F to room temperature on strength was also investigated

Flip the Script

Each one of us must understand education reform as inseparable from our concurrent struggles in other sectors, including labor and healthcare, and the movements to secure full human and civil rights for all. --Authors