14,803 research outputs found
Survival of the Fittest: Federal Law v. State Law in the Context of Successor Liability under CERCLA
Low-temperature embrittlement of Ti-6Al-4V and Inconel-718 by high pressure hydrogen
Notched specimens of titanium alloy and Inconel-718 exhibit little reduction of notch strength at certain low temperatures under 2000 lb/sq in. hydrogen, unnotched specimens are not embrittled at these temperatures. The degree of Inconel-718 embrittlement is lower than earlier observations under 1000 lb/sq in. hydrogen
Micelle Formation and the Hydrophobic Effect
The tendency of amphiphilic molecules to form micelles in aqueous solution is
a consequence of the hydrophobic effect. The fundamental difference between
micelle assembly and macroscopic phase separation is the stoichiometric
constraint that frustrates the demixing of polar and hydrophobic groups. We
present a theory for micelle assembly that combines the account of this
constraint with a description of the hydrophobic driving force. The latter
arises from the length scale dependence of aqueous solvation. The theoretical
predictions for temperature dependence and surfactant chain length dependence
of critical micelle concentrations for nonionic surfactants agree favorably
with experiment.Comment: Accepted for publication in J. Phys. Chem.
Influence of gaseous hydrogen on metals
Tensile, fracture toughness, threshold stress intensity for sustained-load crack growth, and cyclic and sustained load crack growth rate measurements were performed on a number of alloys in high-pressure hydrogen and helium environments. The results of tensile tests performed in 34.5 MN/m2 (5000 psi) hydrogen indicated that Inconel 625 was considerable embrittled at ambient temperature but was not embrittled at 144 K (-200 F). The tensile properties of AISI 321 stainless steel were slightly reduced at ambient temperature and 144 K (-200 F). The tensile properties of Ti-5Al-2.5 Sn ELI were essentially unaffected by hydrogen at 144 K (-200 F). OFHC copper was not embrittled by hydrogen at ambient temperature or at 144 K (-200 F)
Apollo experience report: The cryogenic storage system
A review of the design, development, and flight history of the Apollo cryogenic storage system and of selected components within the system is presented. Discussions are presented on the development history of the pressure vessels, heaters, insulation, and selected components. Flight experience and operational difficulties are reported in detail to provide definition of the problems and applicable corrective actions
Turner, Beard, Chandler: Progressive Historians
For almost half a century, Alfred D. Chandler Jr. has enjoyed an enviable reputation as the most influential business historian in the world. Even in history departments that have shifted their primary focus from politics and economics to society and culture, Chandler remains required reading. Yet, there is one dimension of his scholarship that has thus far been mostly overlooked. And that is its indebtedness to, and refinement of, the genre of historical writing that we customarily label "progressive," a genre whose most prominent exemplars include Frederick Jackson Turner and Charles A. Beard
The First Lunar Ranging Constraints on Gravity Sector SME Parameters
We present the first constraints on pure-gravity sector Standard-Model
Extension (SME) parameters using Lunar Laser Ranging (LLR). LLR measures the
round trip travel time of light between the Earth and the Moon. With 34+ years
of LLR data, we have constrained six independent linear combinations of SME
parameters at the level of to . There is no evidence for
Lorentz violation in the LLR dataset.Comment: 7 pages, presented at the Fourth Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, August 200
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