9,366 research outputs found
A Eutrophication Model of the White River Basin Above Beaver Reservoir in Northwest Arkansas
With national interest focused on manâs ever increasing degradation of the waters in this nation, it is clearly evident that an accurate assessment of all parameters influencing water quality needs to be made. Moreover, nutrient levels and budgets reflecting eutrophication trends are important parameters in the overall factors effecting water quality in lakes and reservoirs. The ability to predict future eutrophication levels will greatly enhance the retardation of the eutrophication process. Through mathematical simulation of this process, eutrophication can be analyzed and intelligent decisions regarding water quality management can be made
Finding Business "Idols": A New Model to Accelerate Start-Ups
Explores a novel approach to finding high-tech entrepreneurial enterprises that is transforming how high-tech entrepreneurs are identified, their businesses launched, and the growth of their operations accelerated
Note on Shape Moduli Stabilization, String Gas Cosmology and the Swampland Criteria
In String Gas Cosmology, the simplest shape modulus fields are naturally
stabilized by taking into account the presence of string winding and momentum
modes. We determine the resulting effective potential for these fields and show
that it obeys the de Sitter conjecture, one of the swampland criteria for
effective field theories to be consistent with superstring theory.Comment: 4 page
Brief Note Effects of Diquat on Amphibian Embryo Development
Author Institution: Department of Biology, State University of New York at Fredoni
Planar Airy beam light-sheet for two-photon microscopy
We demonstrate the first planar Airy light-sheet microscope. Fluorescence
light-sheet microscopy has become the method of choice to study large
biological samples with cellular or sub-cellular resolution. The
propagation-invariant Airy beam enables a ten-fold increase in field-of-view
with single-photon excitation; however, the characteristic asymmetry of the
light-sheet limits its potential for multi-photon excitation. Here we show how
a planar light-sheet can be formed from the curved propagation-invariant Airy
beam. The resulting symmetric light sheet excites two-photon fluorescence
uniformly across an extended field-of-view without the need for deconvolution.
We demonstrate the method for rapid two-photon imaging of large volumes of
neuronal tissue.Comment: 7 pages, 4 figure
Seismic Interferometry using Seismic Noise from Wind Turbines and other Anthropogenic Sources
We investigate seismic noise from anthropogenic sources, in particular wind turbines, for seismic interferometry. The data is from the 17-station Autocorr Seismic Array located in the Midwestern United States. The array has a linear component that extends about 30 km from north to south and a subarray to the south with a diameter of 10 km. The array was deployed from August 2019 to July 2020, which included the initial months of the Covid-19 pandemic. The northernmost seismic stations of the array are located within the southern end of one of the largest onshore wind farms in the world. To the south of the array there are regularly occurring east-west running trains. However even during times when trains are present, the frequency signatures of the wind turbines are dominant over much of the array, including seismic stations well to the south of the wind farm. Although there is vehicle traffic in the region, time windows in the late evening and early morning were chosen to reduce its effect. Shallow refraction data are available nearby individual seismic stations of the array, and since the spectral peaks do not vary for stations with differing basement depths, they are inferred to be source effects of wind turbines. When utilizing seismic interferometry, coherent Rayleigh wave signals are observed for time windows of seismic noise as short as 15 minutes. There are also concurrent estimates of average hourly wind speeds and wind gusts at the locations of the seismic stations. These data show that for ambient noise correlations, clear south propagating Rayleigh waves are observed for moderate to large average hourly wind speeds. For lower wind speeds, less coherent Rayleigh wave signals are observed in the one-hour ambient noise correlations. For seismic stations within the wind farm, both north and south propagating Rayleigh waves are observed in the correlations. However, for seismic stations to the south of the wind farm, only south propagating waves are observed, which are inferred to be coming from the wind farm
Indenture, Marshall County, MS 12 November 1855
https://egrove.olemiss.edu/aldrichcorr_c/1106/thumbnail.jp
The 67 Hz Feature in the Black Hole Candidate GRS 1915+105 as a Possible ``Diskoseismic'' Mode
The Rossi X-ray Timing Explorer (RXTE) has made feasible for the first time
the search for high-frequency (~ 100 Hz) periodic features in black hole
candidate (BHC) systems. Such a feature, with a 67 Hz frequency, recently has
been discovered in the BHC GRS 1915+105 (Morgan, Remillard, & Greiner). This
feature is weak (rms variability ~0.3%-1.6%), stable in frequency (to within ~2
Hz) despite appreciable luminosity fluctuations, and narrow (quality factor Q ~
20). Several of these properties are what one expects for a ``diskoseismic''
g-mode in an accretion disk about a 10.6 M_sun (nonrotating) - 36.3 M_sun
(maximally rotating) black hole (if we are observing the fundamental mode
frequency). We explore this possibility by considering the expected luminosity
modulation, as well as possible excitation and growth mechanisms---including
turbulent excitation, damping, and ``negative'' radiation damping. We conclude
that a diskoseismic interpretation of the observations is viable.Comment: 4 Pages, Latex (emulateapj.sty included), to Appear in ApJ Letters,
Vol. 477, Final Version with Updated Reference
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