4,730 research outputs found
Excerpts from selected LANDSAT 1 final reports in geology
The standard formats for the summaries of selected LANDSAT geological data are presented as checklists. These include: (1) value of LANDSAT data to geology, (2) geologic benefits, (3) follow up studies, (4) cost benefits, (5) optimistic working scales, (6) statistical analysis, and (7) enhancement effects
Quantum equilibration in finite time
It has recently been shown that small quantum subsystems generically
equilibrate, in the sense that they spend most of the time close to a fixed
equilibrium state. This relies on just two assumptions: that the state is
spread over many different energies, and that the Hamiltonian has
non-degenerate energy gaps. Given the same assumptions, it has also been shown
that closed systems equilibrate with respect to realistic measurements. We
extend these results in two important ways. First, we prove equilibration over
a finite (rather than infinite) time-interval, allowing us to bound the
equilibration time. Second, we weaken the non degenerate energy gaps condition,
showing that equilibration occurs provided that no energy gap is hugely
degenerate.Comment: 7 page
Noise-Induced Linearisation and Delinearisation
It is demonstrated, by means of analogue electronic simulation and
theoretically, that external noise can markedly change the character of the
response of a nonlinear system to a low-frequency periodic field. In general,
noise of sufficient intensity {\it linearises} the response. For certain
parameter ranges in particular cases, however, an increase in the noise
intensity can sometime have the opposite effect and is shown to {\it
delinearise} the response. The physical origins of these contrary behaviours
are discussed.Comment: 17 pages. No special macros. Figures on reques
Geology
Papers from private industry reporting applications of remote sensing to oil and gas exploration were presented. Digitally processed LANDSAT images were successfully employed in several geologic interpretations. A growing interest in digital image processing among the geologic user community was shown. The papers covered a wide geographic range and a wide technical and application range. Topics included: (1) oil and gas exploration, by use of radar and multisensor studies as well as by use of LANDSAT imagery or LANDSAT digital data, (2) mineral exploration, by mapping from LANDSAT and Skylab imagery and by LANDSAT digital processing, (3) geothermal energy studies with Skylab imagery, (4) environmental and engineering geology, by use of radar or LANDSAT and Skylab imagery, (5) regional mapping and interpretation, and digital and spectral methods
Techniques for the realization of ultra- reliable spaceborne computer Final report
Bibliography and new techniques for use of error correction and redundancy to improve reliability of spaceborne computer
Recommended from our members
Winter 1973
Field Evaluation of Insecticides for Controlling Mole Crickets in Turf (page 3) Calculations for Turfgrass Culture II: Pesticides (6) Progress in the Control of Turfgrass Weevil, a Species of Hyperodes (9) A Look at USDA\u27s Biological Control of Insect Pests: 1888 to Present (14) Turf Bulletin Index 1970-1973 (23
No evidence for killer sperm or other selective interactions between human spermatozoa in ejaculates of different males in vitro
This study examines one of the possible mechanisms of sperm competition, i.e. the kamikaze sperm hypothesis. This hypothesis states that sperm from different males interact to incapacitate each other in a variety of ways. We used ejaculates from human donors to compare mixes of semen in vitro from the same or different males. We measured the following parameters: (i) the degree of sperm aggregation, velocity and proportion of morphologically normal sperm after 1 and 3 h incubation in undiluted semen samples, (ii) the proportion of viable sperm plus the same parameters as in (i) in 'swim-up' sperm suspensions after 1 and 3 h incubation, (iii) the degree of self and non-self sperm aggregation using fluorescent dyes to distinguish the sperm of different males, and (iv) the extent of sperm capacitation and acrosome-reacted sperm in mixtures of sperm from the same and different males. We observed very few significant changes in sperm aggregation or performance in mixtures of sperm from different males compared with mixtures from the same male and none that were consistent with previously reported findings. The incapacitation of rival sperm therefore seems an unlikely mechanism of sperm competition in humans
On the speed of fluctuations around thermodynamic equilibrium
We study the speed of fluctuation of a quantum system around its
thermodynamic equilibrium state, and show that the speed will be extremely
small for almost all times in typical thermodynamic cases. The setting
considered here is that of a quantum system couples to a bath, both jointly
described as a closed system. This setting, is the same as the one considered
in [N. Linden et al., Phys. Rev. E 79:061103 (2009)] and the ``thermodynamic
equilibrium state'' refers to a situation that includes the usual thermodynamic
equilibrium case, as well as far more general situations
Witnessing eigenstates for quantum simulation of Hamiltonian spectra
The efficient calculation of Hamiltonian spectra, a problem often intractable
on classical machines, can find application in many fields, from physics to
chemistry. Here, we introduce the concept of an "eigenstate witness" and
through it provide a new quantum approach which combines variational methods
and phase estimation to approximate eigenvalues for both ground and excited
states. This protocol is experimentally verified on a programmable silicon
quantum photonic chip, a mass-manufacturable platform, which embeds entangled
state generation, arbitrary controlled-unitary operations, and projective
measurements. Both ground and excited states are experimentally found with
fidelities >99%, and their eigenvalues are estimated with 32-bits of precision.
We also investigate and discuss the scalability of the approach and study its
performance through numerical simulations of more complex Hamiltonians. This
result shows promising progress towards quantum chemistry on quantum computers.Comment: 9 pages, 4 figures, plus Supplementary Material [New version with
minor typos corrected.
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