The effects of temperature gradient and growth rate on the morphology and fatigue properties of MAR-M246(Hf)

MAR-M246(Hf) is a nickel based superalloy used in the turbopump blades of the Space Shuttle main engines. The effects are considered of temperature gradient (G) and growth rate (R) on the microstructure and fatigue properties of this superalloy. The primary dendrite arm spacings were found to be inversely proportional to both temperature gradient and growth rate. Carbide and gamma - gamma prime morphology trends were related to G/R ratios. Weibull analysis of fatigue results shows the characteristic life to be larger by a factor of 10 for the low gradient/fast rate pairing of G and R, while the reliability (beta) was lower

The Ranger 4 Flight Path and Its Determination from Tracking Data

The ranger iv flight path and its determination from tracking dat

Research to develop and define concepts for reliable control sensors - The solid state rate sensors Final report

Solid state device for sensing angular rate by detecting presence of coriolis force

A Survey of the Enteric Group of Fevers in the Middle East, with Special Reference to the Post-War Period, and to the Influence of Immunisation by T.A.B. Vaccine

Abstract Not Provided

Noncontacting devices to indicate deflection and vibration of turbopump internal rotating parts

Published report discusses feasibility of ultrasonic techniques; neutron techniques; X-radiography; optical devices; gamma ray devices; and conventional displacement sensors. Use of signal transmitters in place of slip rings indicated possible improvement and will be subject of futher study

Geology of Northeastern Victoria Land, Antarctica

The northeastern corner of Victoria Land-an area of 50,000 square kilometers east of the Rennick Glacier and north of the Newnes Ice Shelf-was studied geologically during a helicopter-supported reconnaissance in 1964,extending and refining previous work by New Zealand geologists. The oldest rocks of the region are the plutonic rocks of the Freyberg Mountains and other ranges in the southwest part of the region. These schists, gneisses, migmatites, and granitic rocks are presumed to be correlative with the late Precambrian and early Paleozoic terrane of the Transantarctic Mountains. Lying east of these plutonic rocks are low-grade metamorphosed clastic sedimentary rocks presumed to be of middle Paleozoic age; the steep contact with the plutonic rocks appears to be a sheared unconformity. The basal (?) formation, polymict conglomerate and black slate, forms a northwest-trending outcrop belt 10km wide of steeply dipping rocks. Further northeast and presumably next higher stratigraphically is quartzite and quartz conglomerate, forming an outcrop belt 8-15km wide. The remaining metasedimentary rocks belong to the Robertson Bay Formation of metasiltstone and metagraywacke, tightly folded about northwest-trending axes and forming an outcrop belt 150km wide, from the Millen Range to Robertson Bay. Numerous stocks and small batholiths of hornblende-biotite granodiorite intrude and bake the Robertson Bay Formation. The continental Beacon Sandstone, intruded by thick dikes and sills of Jurassic (?) diabase, overlies the older rocks of the southwestern part of the region, and has been brocken by normal faults and folded gently. The Beacon is in turn overlain by plateau basalts. Late Cenozoic basalt-trachyte volcanism along the Ross Sea coast has formed large, north-trending Adare, Hallett, and Daniell Peninsulas and similar Coulman Island. Each of these masses consists largely of volcanic rocks extruded beneath ice sheets at least as thick as 1500m; the continental ice cap was much more extensive at times past than it is now. The volcanic rocks are chaotic palagonite breccias, flow breccias, pillow lavas, and complexes intrusive into them. Subaerial calderas, flows, and cones formed along the crestal rift zones. The pre-Tertiary rocks are upraised along faults at the edge of the Ross Sea. Peaks reaching altitudes of 4000m near the coast attest to the magnitude of late Cenozoic uplift

Parasites and sex

Book ChapterParasites of many kinds have long been recognized as important regulators of population size (e.g., May, 1983b), but only during the last decade or two have they been widely viewed as the protagonists in fast-paced (and long-running) evolutionary thrillers involving subtle features of the biochemistry, anatomy, and behavior of their hosts. On this view, their power as agents of evolution derives from their ubiquity and from the great amounts of mortality they can cause (which are also the properties that make them effective agents of population regulation) and, just as importantly, from their imperfect (but improvable) abilities to defeat the imperfect (but improvable) defenses of their hosts. Thus each party is expected to experience the other as a changeable (and generally worsening) part of its environment

The Generalized Ricci Flow for 3D Manifolds with One Killing Vector

We consider 3D flow equations inspired by the renormalization group (RG) equations of string theory with a three dimensional target space. By modifying the flow equations to include a U(1) gauge field, and adding carefully chosen De Turck terms, we are able to extend recent 2D results of Bakas to the case of a 3D Riemannian metric with one Killing vector. In particular, we show that the RG flow with De Turck terms can be reduced to two equations: the continual Toda flow solved by Bakas, plus its linearizaton. We find exact solutions which flow to homogeneous but not always isotropic geometries

Filler bar heating due to stepped tiles in the shuttle orbiter thermal protection system

An analytical study was performed to investigate the excessive heating in the tile to tile gaps of the Shuttle Orbiter Thermal Protection System due to stepped tiles. The excessive heating was evidence by visible discoloration and charring of the filler bar and strain isolation pad that is used in the attachment of tiles to the aluminum substrate. Two tile locations on the Shuttle orbiter were considered, one on the lower surface of the fuselage and one on the lower surface of the wing. The gap heating analysis involved the calculation of external and internal gas pressures and temperatures, internal mass flow rates, and the transient thermal response of the thermal protection system. The results of the analysis are presented for the fuselage and wing location for several step heights. The results of a study to determine the effectiveness of a half height ceramic fiber gap filler in preventing hot gas flow in the tile gaps are also presented