6,268 research outputs found
Data reduction analysis and application technique development for atmospheric trace gas constituents derived from remote sensors on satellite or airborne platforms
The applicability of the gas filter correlation radiometer (GFCR) to the measurement of tropospheric carbon monoxide gas was investigated. An assessment of the GFRC measurement system to a regional measurement program was conducted through extensive aircraft flight-testing of several versions of the GFRC. Investigative work in the following areas is described: flight test planning and coordination, acquisition of verifying CO measurements, determination and acquisition of supporting meteorological data requirements, and development of supporting computational software
A modular radiative transfer program for gas filter correlation radiometry
The fundamentals of a computer program, simulated monochromatic atmospheric radiative transfer (SMART), which calculates atmospheric path transmission, solar radiation, and thermal radiation in the 4.6 micrometer spectral region, are described. A brief outline of atmospheric absorption properties and line by line transmission calculations is explained in conjunction with an outline of the SMART computational procedures. Program flexibility is demonstrated by simulating the response of a gas filter correlation radiometer as one example of an atmospheric infrared sensor. Program limitations, input data requirements, program listing, and comparison of SMART transmission calculations are presented
Three field tests of a gas filter correlation radiometer
Test flights to remotely measure nonurban carbon monoxide (CO) concentrations by gas filter correlation radiometry are discussed. The inferred CO concentrations obtained through use of the Gas Filter Correlation Radiometer (GFCR) agreed with independent measurements obtained by gas chromatography air sample bottle analysis to within 20 percent. The equipment flown on board the aircraft, the flight test procedure, the gas chromatograph direct air sampling procedure, and the GFCR data analysis procedure are reported
QLC relation and neutrino mass hierarchy
Latest measurements have revealed that the deviation from a maximal solar
mixing angle is approximately the Cabibbo angle, i.e. QLC relation. We argue
that it is not plausible that this deviation from maximality, be it a
coincidence or not, comes from the charged lepton mixing. Consequently we have
calculated the required corrections to the exactly bimaximal neutrino mass
matrix ansatz necessary to account for the solar mass difference and the solar
mixing angle. We point out that the relative size of these two corrections
depends strongly on the hierarchy case under consideration. We find that the
inverted hierarchy case with opposite CP parities, which is known to guarantee
the RGE stability of the solar mixing angle, offers the most plausible scenario
for a high energy origin of a QLC-corrected bimaximal neutrino mass matrix.
This possibility may allow us to explain the QLC relation in connection with
the origin of the charged fermion mass matrices.Comment: 7 pages, 0 figure
Nonlocality and entanglement in the XY model
Nonlocality and quantum entanglement constitute two special features of
quantum systems of paramount importance in quantum information theory (QIT).
Essentially regarded as identical or equivalent for many years, they constitute
different concepts. Describing nonlocality by means of the maximal violation of
two Bell inequalities, we study both entanglement and nonlocality for two and
three spins in the XY model. Our results shed a new light into the description
of nonlocality and the possible information-theoretic task limitations of
entanglement in an infinite quantum system.Comment: 4 pages, 2 figure
Higgs-Mediated tau -> 3 mu in the Supersymmetric Seesaw Model
Recent observations of neutrino oscillations imply non-zero neutrino masses
and flavor violation in the lepton sector, most economically explained by the
seesaw mechanism. Within the context of supersymmetry, lepton flavor violation
(LFV) among the neutrinos can be communicated by renormalization group flow to
the sleptons and from there to the charged leptons. We show that LFV can appear
in the couplings of the neutral Higgs bosons, an effect that is strongly
enhanced at large tan(beta). In particular, we calculate the branching fraction
for tau -> 3 mu and mu -> 3 e mediated by Higgs and find that they can be as
large as 10^{-7} and 5x10^{-14} respectively. These modes, along with B^0 -> mu
mu, can provide important evidence for supersymmetry before direct discovery of
supersymmetric partners occurs. Along with tau -> mu gamma and mu -> e gamma,
they can also provide key insights into the form of the neutrino Yukawa mass
matrix.Comment: 9 pages LaTeX, 2 figures. Added a discussion of mu -> 3e and its
ramifications for probing neutrino mass matrix. Also added references, fixed
typos, and made one notational chang
Stability of Neutrino Mass Degeneracy
Two neutrinos of Majorana masses with mixing angle are
unstable against radiative corrections in the limit , but are stable
for (i.e. opposite CP eigenstates) with which
corresponds to an additional symmetry.Comment: 7 pages, no figure, one reference adde
Bounds on the Higgs-Boson Mass in the Presence of Non-Standard Interactions
The triviality and vacuum stability bounds on the Higgs-boson mass are
revisited in the presence of new interactions parameterized in a
model-independent way by an effective lagrangian. When the scale of new physics
is below 50 TeV the triviality bound is unchanged but the stability lower bound
is increased by 40-60 GeV. Should the Higgs-boson mass be close to its current
lower experimental limit, this leads to the possibility of new physics at the
scale of a few TeV, even for modest values of the effective lagrangian
parameters.Comment: 5 pages, 2 figures, RevTex, submitted to PR
Classification of symmetric periodic trajectories in ellipsoidal billiards
We classify nonsingular symmetric periodic trajectories (SPTs) of billiards
inside ellipsoids of R^{n+1} without any symmetry of revolution. SPTs are
defined as periodic trajectories passing through some symmetry set. We prove
that there are exactly 2^{2n}(2^{n+1}-1) classes of such trajectories. We have
implemented an algorithm to find minimal SPTs of each of the 12 classes in the
2D case (R^2) and each of the 112 classes in the 3D case (R^3). They have
periods 3, 4 or 6 in the 2D case; and 4, 5, 6, 8 or 10 in the 3D case. We
display a selection of 3D minimal SPTs. Some of them have properties that
cannot take place in the 2D case.Comment: 26 pages, 77 figures, 17 table
COST Action TU 1406 quality specifications for roadway bridges (BridgeSpec)
Roadway bridges, being one of the most critical road infrastructures components, require regular maintenance actions. Therefore, it becomes important to define strategies to maximize societal benefits, derived from the investment made in these assets. Consequently, this investment should be planned, effectively managed and technically supported by appropriate management systems, supported in quality control plans. For this purpose, authorities need to produce an asset management plan which should, not only define the goals to be achieved by exploiting the roadway bridge network, but also identify the investment needs and priorities based on a life cycle cost criteria. Additionally, a proper condition assessment of these assets must be conducted to support the decision-making process regarding their preservation. A COST Action recently started in Europe with the aim of standardizing the establishment of quality control plans for roadway bridges. This paper describes this Action and, particularly, its most recent developments.
MaintenanceThis article is based upon work from COST Action TU-1406, Quality specifications for roadway bridges, standardization at a European level (BridgeSpec), supported by COST (European Cooperation in Science and Technology)
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