33,337 research outputs found
Invariant lengths using existing Special Relativity
A field of random space-time events exhibiting complete spatial-temporal
randomness appears statistically identical to all observers. Boost invariant
lengths naturally emerge when we examine fluctuation scales of this field such
as the nearest neighbor distance. If we interpret Planck's length as the
characteristic fluctuation scale of quantum gravity, its boost invariance can
then be understood without modifying Special Relativity.Comment: 5 pages, no figure
Verdi’s six-fours and la parola scenica
Verdi’s operas display many non-normative six-four chords. The question for the opera analyst, however, is not only what occurs musically, but why it does. Is there a dramatic function being served by this mix of harmonic-intervallic instability? We discuss four types of non-normative six-fours in Verdi: the arrival, wonder, evasion, and dissolving. But, even as we individuate these types, we note that they are all similar in one regard: they are all linked to a crucial dramatic statement that Verdi termed la parola scenica, a textual-musical signal that makes a dramatic situation suddenly evident
A Single-armed Manta-board as a New Diver-controlled Planing Board and Its Use for Underwater Surveys
Due to inadequacies of previous underwater towing techniques and the special needs of a recent underwater survey, a modified mania-board technique was developed. With this new technique, the diver holds on to the manta-board with one arm; consequently, the board is referred to as a single-armed manta-board (sam-board). The sam-board proved inexpensive and highly maneuverable, allowing the divers to freely collect samples or record information. Through some experimenting with the board and changing some of the variables, such as rope lengths, towing speeds, etc., a highly efficient towing method can be achieved. Preplanning and strict diving safety procedures must, however, be implemented to assure efficiency. This paper presents the materials, guidelines for board construction, equipment, and preplanning and diving safety procedures necessary for the sam-board towing operation
Geodesic systems of tunnels in hyperbolic 3-manifolds
It is unknown whether an unknotting tunnel is always isotopic to a geodesic
in a finite volume hyperbolic 3-manifold. In this paper, we address the
generalization of this problem to hyperbolic 3-manifolds admitting tunnel
systems. We show that there exist finite volume hyperbolic 3-manifolds with a
single cusp, with a system of at least two tunnels, such that all but one of
the tunnels come arbitrarily close to self-intersecting. This gives evidence
that systems of unknotting tunnels may not be isotopic to geodesics in tunnel
number n manifolds. In order to show this result, we prove there is a
geometrically finite hyperbolic structure on a (1;n)-compression body with a
system of core tunnels such that all but one of the core tunnels
self-intersect.Comment: 19 pages, 4 figures. V2 contains minor updates to references and
exposition. To appear in Algebr. Geom. Topo
Dry Matter and Minerals in Loblolly Pine Plantation on Four Arkansas Soils
Average contents of N, P, K, Ca, and Na and total above ground dry matter were determined in 19-year-old unthinned loblolly pine (Pinus taeda L.) plantations in southeastern Arkansas. Three stands were sampled on each of four sites: well and poorly drained coastal plain soils and well and poorly drained loessial soils. Total dry weights, determined from 15 felled trees on each of the 12 plots, ranged from 127,000 kg/ha on poorly drained loessial soil to 173,300 kg/ha on poorly drained coastal plain soil. Ranking of sites, in descending order of production of dry matter, P, K, and Na was: coastal plain poorly drained, coastal plain well drained, loess well drained, and loess poorly drained. Quantity of Ca in stemwood and stembark was 36% higher on well than poorly drained soils; P was 30% higher on coastal plain than loess soils. Results permit calculation of nutrient drain in timber harvests. Bark in 19-year-old plantations contained 44, 44, 25, and 50% of total N, P, K, and Ca in the stems
Loren Miller: The Petitioners: The Story of the Supreme Court of the United States and the Negro
An improved rocket-borne electric field meter for the middle atmosphere
Improvements in a rocketborne electric field meter designed to measure the atmosphere's electric field and conductivity in the middle atmosphere are described. The general background of the experiment is given as well as changes in the instrument and data processing schemes. Calibration and testing procedures are documented together with suggestions for future work
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