4,647 research outputs found
Use of Deeply Weathered Rock as Landfill Cover Material, Patacon Landfill, Republic of Panama
Under normal conditions weathered rock provides poor landfill cover because of its permeable nature. However, a recent hydrogeological investigation conducted by the US Army Environmental Hygiene Agency (AEHA) of the Patacon Landfill in the Republic of Panama revealed the contrary. The operators were using weathered rock from the surrounding saprolitic outcrops of the Panama formation and Tertiary andesite intrusions for landfill cover. The AEHA selected samples of the weathered rock from the borrow sites for engineering tests at their soils engineering lab at Aberdeen Proving Ground, Maryland. The following are test results. Water induces the weathered rock to slake very quickly to a gravely silt. Compaction of the samples yielded an average Proctor density of 1.74 gm/cm3 at 19 percent optimum moisture content. The lab achieved a low permeability of 6 x 10-7 cm/sec on the compacted samples. The test results suggest that properly prepared weathered rock will substitute as borrow material for landfill cover
Theoretical analysis of the longitudinal behavior of an automatically controlled supersonic interceptor during the attack phase
A theoretical analysis of the effect of engine angular momentum on longitudinal and directional stability in steady rolling maneuvers
Theoretical Analysis of the Longitudinal Behavior of an Automatically Controlled Supersonic Interceptor During the Attack Phase
Theoretical analysis of the longitudinal behavior of an automatically controlled supersonic interceptor during the attack phase against a nonmaneuvering target is presented. Control of the interceptor's flight path is obtained by use of a pitch rate command system. Topics lift, and pitching moment, effects of initial tracking errors, discussion of normal acceleration limited, limitations of control surface rate and deflection, and effects of neglecting forward velocity changes of interceptor during attack phase
A method for estimating variations in the roots of the lateral-stability quartic due to changes in mass and aerodynamic parameters of an airplane
A theoretical analysis of the effect of engine angular momentum on longitudinal and directional stability in steady rolling maneuvers
Theoretical analysis of the longitudinal behavior of an automatically controlled supersonic interceptor during the attack phase against maneuvering and nonmaneuvering targets
Cosmological Supergravity from a Massive Superparticle and Super Cosmological Black Holes
We describe in superspace a classical theory of two dimensional
dilaton supergravity with a cosmological constant, both with and without
coupling to a massive superparticle. We give general exact non-trivial
superspace solutions for the compensator superfield that describes the
supergravity in both cases. We then use these compensator solutions to
construct models of two-dimensional supersymmetric cosmological black holes.Comment: 20 pages, Late
Effective Symmetries of the Minimal Supermultiplet of N = 8 Extended Worldline Supersymmetry
A minimal representation of the N = 8 extended worldline supersymmetry, known
as the `ultra-multiplet', is closely related to a family of supermultiplets
with the same, E(8) chromotopology. We catalogue their effective symmetries and
find a Spin(4) x Z(2) subgroup common to them all, which explains the
particular basis used in the original construction. We specify a constrained
superfield representation of the supermultiplets in the ultra-multiplet family,
and show that such a superfield representation in fact exists for all adinkraic
supermultiplets. We also exhibit the correspondences between these
supermultiplets, their Adinkras and the E(8) root lattice bases. Finally, we
construct quadratic Lagrangians that provide the standard kinetic terms and
afford a mixing of an even number of such supermultiplets controlled by a
coupling to an external 2-form of fluxes.Comment: 13 Figure
Nonequilibrium stationary states with Gibbs measure for two or three species of interacting particles
We construct explicit examples of one-dimensional driven diffusive systems
for two and three species of interacting particles, defined by asymmetric
dynamical rules which do not obey detailed balance, but whose nonequilibrium
stationary-state measure coincides with a prescribed equilibrium Gibbs measure.
For simplicity, the measures considered in this construction only involve
nearest-neighbor interactions. For two species, the dynamics thus obtained
generically has five free parameters, and does not obey pairwise balance in
general. The latter property is satisfied only by the totally asymmetric
dynamics and the partially asymmetric dynamics with uniform bias, i.e., the
cases originally considered by Katz, Lebowitz, and Spohn. For three species of
interacting particles, with nearest-neighbor interactions between particles of
the same species, the totally asymmetric dynamics thus obtained has two free
parameters, and obeys pairwise balance. These models are put in perspective
with other examples of driven diffusive systems. The emerging picture is that
asymmetric (nonequilibrium) stochastic dynamics leading to a given
stationary-state measure are far more constrained (in terms of numbers of free
parameters) than the corresponding symmetric (equilibrium) dynamics.Comment: 18 pages, 8 tables, 1 figure. Stylistic and other minor improvement
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