590 research outputs found
Empirically Investigating the Impact of Antenna Polarization and Modulation Parameters on Subsoil Communication Range in LoRa Networks
The Long Range (LoRa) network has been widely acknowledged for its efficiency and reliability in terrestrial sensing applications. However, building a robust LoRa network in the subsoil environment, which presents challenges for radio communication, remains challenging. This study evaluates the impact of antenna polarization and LoRa modulation parameters, such as bandwidth and spreading factor, on subsoil communication ranges. Based on the results of our experiments, we propose practical LoRa network configurations for the seamless transmission of subsoil sensory data to the surface.</p
Further investigations into immunization of cattle against rinderpest
1. Kabete goat virus was not transmitted from reacting to susceptible
cattle under conditions of close contact.
2. A single doubtful transmission was recorded under conditions of
open grazing.
3. A febrile condition of unknown aetiology transmissible from cattle
to goats was encountered.
4. Urine from reacting animals was non-infective, but faeces in one
out of two cases was infective by drenching.
5. Immunity produced by a single injection of formal-glycerine spleen-vaccine
had completely disappeared after 8 months.
6. Immunity produced by triple vaccination with formal-saline vaccine
had diminished considerably after 8 months.
7. Triple vaccination followed by a single injection of formal-glycerine
spleen vaccine 9 months later produced an immunity which persisted for
at least 20 months.
8. The rapid production of immunity induced by a single injection
of formal-glycerine spleen-vaccine could be used to control the reaction
to K.G.V. An interval of 7 days between vaccine and virus appeared to
be the optimum.
9. Spleen-vaccine prepared from cattle reacting to K.G.V. has an
inferior antigenic potency.
10. The reaction produced by K.G.V. in grade cattle (British breeds
of cattle x Zebu) are severe but usually non-fatal. A durable immunity
follows the reaction.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
On the equivalence between the Boltzmann equation and classical field theory at large occupation numbers
We consider a system made up of exictations of a neutral scalar field, \phi,
having a \lambda\phi^4 interaction term. Starting from an ensemble where the
occupation number f is large, but \lambda f is small, we develop a classical
field theory description of the evolution of the system toward equilibrium. A
Boltzmann equation naturally emerges in this description and we show by
explicit calculation that the collision term is the same as that coming from
elastic scattering. This shows the equivalence of a Boltzmann equation
description and a classical field theory description of the same system.Comment: 15 pages, 7 figure
On chip optical neural networks based on MMI microring resonators for image classification
We propose a new on-chip optical neural network (OONN) based on multimode interference-microring resonators (MMI-RRs). The suggested structure eliminates the need for wavelength division multiplexers (WDM) to create an optical neuron on a single chip. New microring resonator structure based on 4×4 MMI coupler with a size of 24µm × 2900 µm is used for the basic elements of the computation matrix, as a result a higher bandwidth and free spectral range (FSR) can be achieved. The Si3N4 platform along with the graphene sheet is designed to modulate the signals and weights of the neural networks at a very high speed. The Si3N4 can provide wide range of operating wavelengths and can work directly with the wavelengths of color images. The structure's benefits include rapid computing speed, little loss, and the ability to handle both positive and negative values. The OONN has been applied to the MNIST dataset with a speed faster than 2.8 to 14x times compared with the conventional GPU methods.This research is funded by Vietnam National Founda-tion for Science and Technology Development (NA-FOSTED) under grant number 103.03-2018.354
Gluon self-energy in a two-flavor color superconductor
The energy and momentum dependence of the gluon self-energy is investigated
in a color superconductor with two flavors of massless quarks. The presence of
a color-superconducting quark-quark condensate modifies the gluon self-energy
for energies which are of the order of the gap parameter. For gluon energies
much larger than the gap, the self-energy assumes the form given by the
standard hard-dense loop approximation. It is shown that this modification of
the gluon self-energy does not affect the magnitude of the gap to leading and
subleading order in the weak-coupling limit.Comment: 21 pages, 6 figures, RevTeX, aps and epsfig style files require
Debye screening and Meissner effect in a two-flavor color superconductor
I compute the gluon self-energy in a color superconductor with two flavors of
massless quarks, where condensation of Cooper pairs breaks SU(3)_c to SU(2)_c.
At zero temperature, there is neither Debye screening nor a Meissner effect for
the three gluons of the unbroken SU(2)_c subgroup. The remaining five gluons
attain an electric as well as a magnetic mass. For temperatures approaching the
critical temperature for the onset of color superconductivity, or for gluon
momenta much larger than the color-superconducting gap, the self-energy assumes
the form given by the standard hard-dense loop approximation. The gluon
self-energy determines the coefficient of the kinetic term in the effective
low-energy theory for the condensate fields.Comment: 29 pages, RevTe
Stochastic String Motion Above and Below the World Sheet Horizon
We study the stochastic motion of a relativistic trailing string in black
hole AdS_5. The classical string solution develops a world-sheet horizon and we
determine the associated Hawking radiation spectrum. The emitted radiation
causes fluctuations on the string both above and below the world-sheet horizon.
In contrast to standard black hole physics, the fluctuations below the horizon
are causally connected with the boundary of AdS. We derive a bulk stochastic
equation of motion for the dual string and use the AdS/CFT correspondence to
determine the evolution a fast heavy quark in the strongly coupled
plasma. We find that the kinetic mass of the quark decreases by while the correlation time of world sheet
fluctuations increases by .Comment: 27 pages, 5 figures; v2 final version, small changes, references
adde
On the Perturbative Nature of Color Superconductivity
Color superconductivity is a possible phase of high density QCD. We present a
systematic derivation of the transition temperature, T_C, from the QCD
Lagrangian through study of the di-quark proper vertex. With this approach, we
confirm the dependence of T_C on the coupling g, namely , previously obtained from the one-gluon exchange approximation
in the superconducting phase. The diagrammatic approach we employ allows us to
examine the perturbative expansion of the vertex and the propagators. We find
an additional O(1) contribution to the prefactor of the exponential from the
one-loop quark self energy and that the other one-loop radiative contributions
and the two gluon exchange vertex contribution are subleading.Comment: 13 pages, 3 figures, revtex, details and discussion expande
Supersymmetry of the Schrodinger and PP Wave Solutions in Einstein-Weyl Supergravities
We obtain the Schrodinger and general pp-wave solutions with or without the
massive vector in Einstein-Weyl supergravity. The vector is an auxiliary field
in the off-shell supermultiplet and it acquires a kinetic term in the
Weyl-squared super invariant. We study the supersymmetry of these solutions and
find that turning on the massive vector has a consequence of breaking all the
supersymmetry. The Schrodinger and also the pp-wave solutions with the massive
vector turned off on the other hand preserve 1/4 of the supersymmetry.Comment: 13 pages, no figur
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