4,336 research outputs found
Encouraging Corporate Innovation for Our Homeland During the Best of Times for the Worst of Times: Extending Safety Act Protections to Natural Disasters’
This article first analyzes the innovative tort reform of the SAFETY Act and then argues for expansion of SAFETY Act type risk protection to natural disasters such as hurricanes, earthquakes and wildfires. The SAFETY Act was drafted to stimulate the development and deployment of technologies that combat terrorism by providing liability protection. Applying the same type of legislation to natural disasters will provide a commensurate benefit of encouraging preparedness and development of technologies that could mitigate harms resulting from natural disasters. The Department of Homeland Security voiced a desire to increase the use of the SAFETY Act by private industry. This article argues that one way to increase the utility of the SAFETY Act and provide more value for the American public is for Congress to extend SAFETY Act protections, by amendment or new legislation, to cover risk related to national catastrophes
Military Space Communications
A worldwide network of military communication satellites is now being deployed to function both as a long-haul strategic trunking system and as a system capable of supporting contingency operations. Another network is under development to handle voice and teletype messages between users with small mobile terminals. Other more specialized satellite systems are well along in the planning stage. This paper describes the evolving deployment and utilization of satellite-based systems and anticipates the trend in future operational capability
High-speed measurement of rotational anisotropy nonlinear optical harmonic generation using position sensitive detection
We present a method of performing high-speed rotational anisotropy nonlinear
optical harmonic generation experiments at rotational frequencies of several
hertz by projecting the harmonic light reflected at different angles from a
sample onto a stationary position sensitive detector. The high rotational speed
of the technique, to times larger than existing methods, permits
precise measurements of the crystallographic and electronic symmetries of
samples by averaging over low frequency laser power, beam pointing, and pulse
width fluctuations. We demonstrate the sensitivity of our technique by
resolving the bulk four-fold rotational symmetry of GaAs about its [001] axis
using second harmonic generation
KINEMATIC AND TEMPORAL CHARACTERISfICS OF SELECTED JUDO HIP THROWS
The sport of judo, developed In 1882 in Japan by Jigoro Kano, is a refined version of the ancient martial art of jujitsu. Typically when one envisions martial arts, the mental image includes kicks, punches, and other striking techniques. The sport of judo involves none of these, but does permit the use of throwing techniques, mat work similar to wrestling, strangle holds and joint
locks at the elbow. Despite its original role as a martial art, judo as practiced today is essentially the highest form of wrestling practiced anywhere in the world (Reay &Hobbs, 1979)
Lack of neuromuscular origins of adaptation after a long-term stretching program
pre-printContext: Static stretching is commonly used during the treatment and rehabilitation of orthopedic injuries to increase joint range of motion (ROM) and muscle flexibility. Understanding the physiological adaptations that occur in the neuromuscular system as a result of long-term stretching may provide insight into the mechanisms responsible for changes in flexibility. Objective: To examine possible neurological origins and adaptations in the Ia-reflex pathway that allow for increases in flexibility in ankle ROM, by evaluating the reduction in the synaptic transmission of Ia afferents to the motoneuron pool. Design: Repeated-measures, case-controlled study. Setting: Sports medicine research laboratory. Participants: 40 healthy volunteers with no history of cognitive impairment, neurological impairment, or lower extremity surgery or injury within the previous 12 mo. Intervention: Presynaptic and postsynaptic mechanisms were evaluated with a chronic stretching protocol. Twenty subjects stretched 5 times a wk for 6 wk. All subjects were measured at baseline, 3 wk, and 6 wk. Main Outcome Measures: Ankle-dorsiflexion ROM, Hmax:Mmax, presynaptic inhibition, and disynaptic reciprocal inhibition. Results: Only ROM had a significant interaction between group and time, whereas the other dependent variables did not show significant differences. The experimental group had significantly improved ROM from baseline to 3 wk (mean 6.2 ± 0.9, P < .001), 3 wk to 6 wk (mean 5.0 ± 0.8, P < .001), and baseline to 6 wk (mean 11.2 ±0.9, P < .001). Conclusions: Ankle dorsiflexion increased by 42.25% after 6 wk of static stretching, but no significant neurological changes resulted at any point of the study, contrasting current literature. Significant neuromuscular origins of adaptation do not exist in the Ia-reflex-pathway components after a long-term stretching program as currently understood. Thus, any increases in flexibility are the result of other factors, potentially mechanical changes or stretch tolerance
Enhanced heat capacity and a new temperature instability in superfluid He-4 in the presence of a constant heat flux near T-lambda
We present the first experimental evidence that the heat capacity of superfluid 4He, at temperatures very close to the lambda point Tλ, is enhanced by a constant heat flux Q. The heat capacity at constant Q, CQ, is predicted to diverge at a temperature Tc(Q)<Tλ at which superflow becomes unstable. In agreement with previous measurements, we find that dissipation enters our cell at a temperature, TDAS(Q), below the theoretical value, Tc(Q). We argue that TDAS(Q) can be accounted for by a temperature instability at the cell wall, and is therefore distinct from Tc(Q). The excess heat capacity we measure has the predicted scaling behavior as a function of T and Q, but it is much larger than predicted by current theory
Nuclear Tetrahedral Symmetry: Possibly Present Throughout the Periodic Table
More than half a century after the fundamental, spherical shell structure in
nuclei has been established, theoretical predictions indicate that the
shell-gaps comparable or even stronger than those at spherical shapes may
exist. Group-theoretical analysis supported by realistic mean-field
calculations indicate that the corresponding nuclei are characterized by the
('double-tetrahedral') group of symmetry, exact or approximate. The
corresponding strong shell-gap structure is markedly enhanced by the existence
of the 4-dimensional irreducible representations of the group in question and
consequently it can be seen as a geometrical effect that does not depend on a
particular realization of the mean-field. Possibilities of discovering the
corresponding symmetry in experiment are discussed.Comment: 4 pages in LaTeX and 4 figures in eps forma
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