2,155 research outputs found
Land application of sewage effluent for Missouri water resources conservation and pollution control
The overall objectives of this study are twofold: 1) to demonstrate the viability and effectiveness of land treatment system to renovate lagoon effluent quality in Missouri and elsewhere in the Midwest; and 2) to conduct a comprehensive and systematic study to develop pertinent design and operating parameters that can be successfully used by other communities in the region. The report described herein represents the results that is necesssary before further development can be initiated. These results are: 1) community background survey; 2) current and proposed waste management methods; and 3) existing surface and subsurface water qualities at application site. Emphasis of the discussion is placed on the technical data which have a direct bearing on the future evaluation of the water quality improvement as a result of land application.Project # G-852 Agreement # 14-08-000
Theory of coherent acoustic phonons in InGaN/GaN multi-quantum wells
A microscopic theory for the generation and propagation of coherent LA
phonons in pseudomorphically strained wurzite (0001) InGaN/GaN multi-quantum
well (MQW) p-i-n diodes is presented. The generation of coherent LA phonons is
driven by photoexcitation of electron-hole pairs by an ultrafast Gaussian pump
laser and is treated theoretically using the density matrix formalism. We use
realistic wurzite bandstructures taking valence-band mixing and strain-induced
piezo- electric fields into account. In addition, the many-body Coulomb
ineraction is treated in the screened time-dependent Hartree-Fock
approximation. We find that under typical experimental conditions, our
microscopic theory can be simplified and mapped onto a loaded string problem
which can be easily solved.Comment: 20 pages, 17 figure
Selection rules in three-body B decay from factorization
Extending the dynamics underlying the factorization calculation of two-body
decays, we propose simple selection rules for nonresonant three-body B decays.
We predict, for instance, that in the Dalitz plot of B^0-->D^0-bar\pi^+\pi^-,
practically no events should be found in the corner of E(\pi^+) < \Lambda_{QCD}
as compared with the corner of E(\pi^-) < \Lambda_{QCD}. We also predict that
there should be very few three-body decay events with a soft meson resonance
and two energetic mesons or meson resonances. The selection rules are quite
different from the soft pion theorem, since they apply to different kinematical
regions. For B^0 -->D^0-bar\pi^+\pi^-, the latter predicts that the decay
matrix element vanishes in the zero-four-momentum limit of \pi^+ instead of
\pi^-. Since this marked difference from the soft pion theorem is directly
related to the issue of short-distance QCD dominance in the FSI of two-body B
decays, experimental test of the selection rules will shed light on strong
interaction dynamics of B decay.Comment: 12 pages in REVTEX including 3 eps figure
Recommended from our members
Evaluation of multi-phase heat transfer and droplet evaporation in petroleum cracking flows
A computer code ICRKFLO was used to simulate the multiphase reacting flow of fluidized catalytic cracking (FCC) riser reactors. The simulation provided a fundamental understanding of the hydrodynamics and heat transfer processes in an FCC riser reactor, critical to the development of a new high performance unit. The code was able to make predictions that are in good agreement with available pilot-scale test data. Computational results indicate that the heat transfer and droplet evaporation processes have a significant impact on the performance of a pilot-scale FCC unit. The impact could become even greater on scale-up units
Massive vector trapping as a gauge boson on a brane
We propose a mechanism to trap massive vector fields as a photon on the
Randall-Sundrum brane embedded in the five dimensional AdS space. This
localization-mechanism of the photon is realized by considering a brane action,
to which a quadratic potential of the bulk-vector fields is added. We also
point out that this potential gives several constraints on the fluctuations of
the vector fields in the bulk space.Comment: 11 pages, no figure, LaTe
flatIGW - an inverse algorithm to compute the Density of States of lattice Self Avoiding Walks
We show that the Density of States (DoS) for lattice Self Avoiding Walks can
be estimated by using an inverse algorithm, called flatIGW, whose step-growth
rules are dynamically adjusted by requiring the energy histogram to be locally
flat. Here, the (attractive) energy associated with a configuration is taken to
be proportional to the number of non-bonded nearest neighbor pairs (contacts).
The energy histogram is able to explicitly direct the growth of a walk because
the step-growth rule of the Interacting Growth Walk \cite{IGW} samples the
available nearest neighbor sites according to the number of contacts they would
make. We have obtained the complex Fisher zeros corresponding to the DoS,
estimated for square lattice walks of various lengths, and located the
temperature by extrapolating the finite size values of the real zeros to their
asymptotic value, (reasonably close to the known value,
\cite{barkema}).Comment: 18 pages, 7 eps figures; parts of the manuscript are rewritten so as
to improve clarity of presentation; an extra reference adde
Skyrmion Excitation in Two-Dimensional Spinor Bose-Einstein Condensate
We study the properties of coreless vortices(skyrmion) in spinor
Bose-Einstein condensate. We find that this excitation is always energetically
unstable, it always decays to an uniform spin texture. We obtain the skyrmion
energy as a function of its size and position, a key quantity in understanding
the decay process. We also point out that the decay rate of a skyrmion with
high winding number will be slower. The interaction between skyrmions and other
excitation modes are also discussed.Comment: 5 pages, 4 figures, final version published in Phys. Rev.
- …