4,703 research outputs found
The bond stress in a viscoelastic propellant disk during thermal shock
Analysis of bond stress in viscoelastic case bonded solid propellant rocket assembly during thermal shoc
Thermal stresses in chemically hardening elastic media with application to the molding process
Thermal stresses in chemically hardened elastic media and applications to molding processe
Transient temperature distribution during an exothermic chemical reaction
Heat conduction equation for determining temperature distribution during exothermic chemical reactio
Residual stresses developed in molding a flat sheet of a chemically-hardening relatively incompressible material
Approximation of residual thermal stresses in flat sheet molded from chemical hardening material
A Strategic Approach to Agricultural Research Program Planning in Sub-Saharan Africa
Recent studies have shown that agricultural research can have high payoffs in Africa, but impact depends on how well technology fits with evolving needs and capacity in the agricultural sector and the rest of the economy. Structural adjustment policies (e.g., market liberalization, currency devaluation) and political change are transforming user demands for new technology and the economic environment in which technology must perform. The challenge is how to design agricultural research as a strategic input to promote broad-based economic growth, structural transformation, and food security in the increasingly market-driven, but fragile, economies of Africa.Food Security, Food Policy, Agricultural Research, Research and Development/Tech Change/Emerging Technologies, Downloads May 2008-July 2009: 44, Q18,
A Strategic Approach to Agricultural Research Program Planning in Sub-Saharan Africa
Research and Development/Tech Change/Emerging Technologies, Downloads May 2008-July 2009: 13,
Low Frequency Tilt Seismology with a Precision Ground Rotation Sensor
We describe measurements of the rotational component of teleseismic surface
waves using an inertial high-precision ground-rotation-sensor installed at the
LIGO Hanford Observatory (LHO). The sensor has a noise floor of 0.4 nrad at 50 mHz and a translational coupling of less than 1 rad/m
enabling translation-free measurement of small rotations. We present
observations of the rotational motion from Rayleigh waves of six teleseismic
events from varied locations and with magnitudes ranging from M6.7 to M7.9.
These events were used to estimate phase dispersion curves which shows
agreement with a similar analysis done with an array of three STS-2
seismometers also located at LHO
Rydberg trimers and excited dimers bound by internal quantum reflection
Quantum reflection is a pure wave phenomena that predicts reflection of a
particle at a changing potential for cases where complete transmission occurs
classically. For a chemical bond, we find that this effect can lead to
non-classical vibrational turning points and bound states at extremely large
interatomic distances. Only recently has the existence of such ultralong-range
Rydberg molecules been demonstrated experimentally. Here, we identify a broad
range of molecular lines, most of which are shown to originate from two
different novel sources: a single-photon associated triatomic molecule formed
by a Rydberg atom and two ground state atoms and a series of excited dimer
states that are bound by a so far unexplored mechanism based on internal
quantum reflection at a steep potential drop. The properties of the Rydberg
molecules identified in this work qualify them as prototypes for a new type of
chemistry at ultracold temperatures.Comment: 6 pages, 3 figures, 1 tabl
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