11,022 research outputs found
Investigation to relate the chlorophyll and suspended sediment content in the waters of the lower Chesapeake Bay to ERTS-1 imagery
There are no author-identified significant results in this report
Correlation of ERTS multispectral imagery with suspended matter and chlorophyll in lower Chesapeake Bay
The feasibility of using multispectral satellite imagery to monitor the characteristics of estuarine waters is being investigated. Preliminary comparisons of MSS imagery with suspended matter concentrations, particle counts, chlorophyll, transmittance and bathymetry have been made. Some visual correlation of radiance with particulates and chlorophyll has been established. Effects of bathymetry are present, and their relation to transmittance and radiance is being investigated. Greatest detail in suspended matter is revealed by MSS band 5. Near-surface suspended sediment load and chlorophyll can be observed in bands 6 and 7. Images received to date have partially defined extent and location of high suspensate concentrations. Net quantity of suspended matter in the lower Bay has been decreasing since the inception of the study, and represents the diminution of turbid flood waters carried into the Bay in late September, 1972. The results so far point to the utility of MSS imagery in monitoring estuarine water character for the assessment of siltation, productivity, and water types
Evolution of the bilayer nu = 1 quantum Hall state under charge imbalance
We use high-mobility bilayer hole systems with negligible tunneling to
examine how the bilayer nu = 1 quantum Hall state evolves as charge is
transferred from one layer to the other at constant total density. We map
bilayer nu = 1 state stability versus imbalance for five total densities
spanning the range from strongly interlayer coherent to incoherent. We observe
competition between single-layer correlations and interlayer coherence. Most
significantly, we find that bilayer systems that are incoherent at balance can
develop spontaneous interlayer coherence with imbalance, in agreement with
recent theoretical predictions.Comment: 4 pages, 4 figure
The utilization of selection after 100-days lactation in forming a high productive Red and White herd
International audienc
Optically trapped atom interferometry using the clock transition of large Rb-87 Bose-Einstein condensates
We present a Ramsey-type atom interferometer operating with an optically
trapped sample of 10^6 Bose-condensed Rb-87 atoms. The optical trap allows us
to couple the |F =1, mF =0>\rightarrow |F =2, mF =0> clock states using a
single photon 6.8GHz microwave transition, while state selective readout is
achieved with absorption imaging. Interference fringes with contrast
approaching 100% are observed for short evolution times. We analyse the process
of absorption imaging and show that it is possible to observe atom number
variance directly, with a signal-to-noise ratio ten times better than the
atomic projection noise limit on 10^6 condensate atoms. We discuss the
technical and fundamental noise sources that limit our current system, and
outline the improvements that can be made. Our results indicate that, with
further experimental refinements, it will be possible to produce and measure
the output of a sub-shot-noise limited, large atom number BEC-based
interferometer.
In an addendum to the original paper, we attribute our inability to observe
quantum projection noise to the stability of our microwave oscillator and
background magnetic field. Numerical simulations of the Gross-Pitaevskii
equations for our system show that dephasing due to spatial dynamics driven by
interparticle interactions account for much of the observed decay in fringe
visibility at long interrogation times. The simulations show good agreement
with the experimental data when additional technical decoherence is accounted
for, and suggest that the clock states are indeed immiscible. With smaller
samples of 5 \times 10^4 atoms, we observe a coherence time of {\tau} =
(1.0+0.5-0.3) s.Comment: 22 pages, 6 figures Addendum: 11 pages, 6 figure
Correlation of chlorophyll, suspended matter, and related parameters of waters in the lower Chesapeake Bay area to LANDSAT-1 imagery
The author has identified the following significant results. An effort to relate water parameters of the lower Chesapeake Bay area to multispectral scanner images of LANDSAT 1 has shown that some spectral bands can be correlated to water parameters, and has demonstrated the feasibility of synoptic mapping of estuaries by satellite. Bands 5 and 6 were shown to be useful for monitoring total particles. Band 5 showed high correlation with suspended sediment concentration. Attenuation coefficients monitored continuously by ship along three baselines were cross correlated with radiance values on three days. Improved correlations resulted when tidal conditions were taken into consideration. A contouring program was developed to display sediment variation in the lower Chesapeake Bay from the MSS bands
Factors affecting pesticide drift
Minimizing potential drift is a primary responsibility for every applicator. Despite conscientious efforts, about one to three applications per Iowa county each year result in drift complaints investigated by the Iowa Department of Agriculture and Land Stewardship.https://lib.dr.iastate.edu/extension_ag_pubs/1174/thumbnail.jp
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