648 research outputs found
Assessment of shelf sea tides and tidal mixing fronts in a global ocean model
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148272/1/ocemod_2019_shelftidesandfronts_timkoetal.pdfDescription of ocemod_2019_shelftidesandfronts_timkoetal.pdf : Main articl
Efficiency of molecular markers to select for Striga gesnerioides resistance in cowpca [Vigna unguiculata (L.)Walp]
Striga gesnerioides (Willd) Vatke is a major biological constraint to cowpea productivity in the dl)
savannas of sub-Saharan Africa. Over the last two decades, the use of molecular markers in crop improvemem
has gained prominence owing to its ability to sh0l1en the breeding cycle. The available molecular markel
techniques are being improved upon and continuously tested for higher preci sion, shOl1er duration of application
and better cost effectiveness. [n the present study, a total of four molecular markers developed for selecting
Slriga resistant cowpea were used to genotype F2 population derived from a cross between Borno Brown and
[T97K-499-35 to identify markers more close ly linked to S. gesnerioides resistance. SSRI and 2 were found 10
be tight ly linked to Striga gesnerioides with a genetic distance of 1 and 2cM.The selection efficiency of SS~I
and SSR-2 were 99 and 98 % and was better than that of C42-B 85.5%
Peculiarities of nonadditive changes in conductivity of nano-PDLC under influence of magnetite and single-wall carbon nanotubes
Studied in this work has been the effect of nanoparticles – magnetite and
single-wall carbon nanotubes – separately and together on the conductivity of nematic
liquid crystal 6CHBT dispersed in polyvinyl alcohol. Morphology of these films was
analyzed using an electron microscope. When using selected technologyof homogenizing
the mixture components, there takes place formation of liquid crystals dispersed in the
polymer matrix with the average sizes of liquid-crystal droplets close to 500 nm (nanoPDLC).
It has been found that simultaneous introduction of magnetite and nanotubes
results in lowering the conductivity of nano-PDLC as compared to the total conductivity
of nano-PDLC with each kind of nanoparticles separately. It has been suggested that the
main mechanism of this effect lies in formation of deep centers for electron capture by
complexes with different types of nanoparticles, which leads to a decrease in electronic
conductivity through the polymer matrix
Nonadditive changes in conductivity of micro PDLC under the influence of carbon nanotubes and magnetic nanoparticles
Investigated in this work has been the effect of impurities – magnetic
nanoparticles (MN) and multiwall carbon nanotubes (MWNT) – separately and together
on morphology and dielectric properties of nematic liquid crystal 6CHBT dispersed in
polyvinyl alcohol (PDLC). It has been shown that the nanoparticles and nanotubes
together change the morphology of PDLC practically in the same manner as every type
of impurity singly. The impurities influence also additively on the permittivity at low
frequencies and electron component of the conductivity in the polymer matrix. We have
found that when MN and MWNT act jointly their ion component of the conductivity
exceeds the total changes in conductivity by six times greater than when each type of
impurity acts singly. The most probable reason for this nonadditive change in
conductivity can be aggregation of these nanoparticles
Effect of magnetic nanoparticles with various geometrical shapes on morphology and dielectric properties of nanodispersions of nematic liquid crystal in polymer matrix
Prepared in this work are dispersions of nematic liquid crystal in polyvinyl
alcohol with sizes of liquid phase inclusions less than one micrometer (nano-polymer
dispersed liquid crystal (PDLC)) by changing technology of mixing the components. It
was shown that, like to the case of earlier examined dispersions with the droplet sizes 6
to 10 μm (micro-PDLC), the conductivity of nano-PDLC has two components: the ion
one, which value does not depend on frequency, and the electron one, the value of which
depends on frequency according to a power law. It was found that the ion conductivity of
nano-PDLC is three orders of magnitude higher than that for micro-PDLC, and the
exponent for the electron components of nano-PDLC conductivity is less than that for
micro-PDLC. It was shown that the spherical and rod-like magnetic nanoparticles (MNs)
influence in a different manner on the conductivity components of nano-PDLC. If for the
maximum concentration of spherical MNs 2 * 10⁻³ wt.% the ion conductivity is 2-fold
increased, then at the same concentration of rod-like MNs the ion conductivity value
increases by more than one order of magnitud
Morphology and dielectric properties of polymer dispersed liquid crystal with magnetic nanoparticles
It has been shown that introduction of magnetic nanoparticles (MN) of various
shapes with the concentration 10⁻¹ wt.% into polymer dispersed liquid crystal (PDLC)
causes two effects: the size of liquid crystal droplets decreases, and the amount of the
latter with through holes increases. MN increase the effective value of permittivity by
more than one order within the frequency range 10⁻¹⁺ -10² HZ , as well as the electron
and ion components of conductivity. MN reduce the exponent in the frequency
dependence of the electron component of conductivity. The changes caused by the
presence of the nanoparticles quantitatively depend on their shape
Search for charged Higgs decays of the top quark using hadronic tau decays
We present the result of a search for charged Higgs decays of the top quark,
produced in collisions at 1.8 TeV. When the charged
Higgs is heavy and decays to a tau lepton, which subsequently decays
hadronically, the resulting events have a unique signature: large missing
transverse energy and the low-charged-multiplicity tau. Data collected in the
period 1992-1993 at the Collider Detector at Fermilab, corresponding to
18.70.7~pb, exclude new regions of combined top quark and charged
Higgs mass, in extensions to the standard model with two Higgs doublets.Comment: uuencoded, gzipped tar file of LaTeX and 6 Postscript figures; 11 pp;
submitted to Phys. Rev.
Search for Chargino-Neutralino Associated Production at the Fermilab Tevatron Collider
We have searched in collisions at = 1.8 TeV for events
with three charged leptons and missing transverse energy. In the Minimal
Supersymmetric Standard Model, we expect trilepton events from
chargino-neutralino (\chione \chitwo) pair production, with subsequent decay
into leptons. We observe no candidate , ,
or events in 106 pb integrated
luminosity. We present limits on the sum of the branching ratios times cross
section for the four channels: \sigma_{\chione\chitwo}\cdot
BR(\chione\chitwo\to 3\ell+X) 81.5 \mgev\sp and
M_\chitwo > 82.2 \mgev\sp for , ~\mgev\sp and
M_\squark= M_\gluino.Comment: 9 pages and 3 figure
Inclusive jet cross section in collisions at TeV
The inclusive jet differential cross section has been measured for jet
transverse energies, , from 15 to 440 GeV, in the pseudorapidity region
0.10.7. The results are based on 19.5 pb of data
collected by the CDF collaboration at the Fermilab Tevatron collider. The data
are compared with QCD predictions for various sets of parton distribution
functions. The cross section for jets with GeV is significantly
higher than current predictions based on O() perturbative QCD
calculations. Various possible explanations for the high- excess are
discussed.Comment: 8 pages with 2 eps uu-encoded figures Submitted to Physical Review
Letter
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