1,285 research outputs found
Perspectives for biogas generation from manure on the farms in the Leningrad Region of the Russian Federation
Received: January 27th, 2021 ; Accepted: March 28th, 2021 ; Published: April 8th, 2021 ; Correspondence: [email protected] interest in biogas in the Leningrad Region is consistently growing. Biogas can
replace fossil fuels in different applications and reduce greenhouse gas emissions. The study aimed
to demonstrate the perspectives for its generation from livestock waste and further farm application.
The farm energy audits identified the pattern of fuel and energy consumption. Computational and
statistical methods were applied to estimate the biogas generation. First, the study considered a
cattle farm with 1,800 head and manure output of 43,300 t year-1
. According to calculations, the
farm can fully meet its own needs for electricity or motor fuel by converting the manure into
biogas. Meanwhile, the fuel use of biogas can reduce pollutant emissions by almost 30% against
conventional fuel. Secondly, the study estimated the biogas production potential from the farm
organic waste in the whole Leningrad Region with the total cattle stock of 165,000 head, pig
stock of 184,000 head, and poultry stock of 29,180,000 head, producing about 8 million t year-1
of animal/poultry manure. According to calculations, the livestock waste processing will yield up
to 500 million m3 of biogas. This is enough to fully cover the energy inputs of the farms in this
region. However, the payback period for biogas plants is above eight years. The positive aspects
of biogas application are introducing biogas in the farm energy balance as an energy resource;
reducing the hazardous emissions owing to the improved processing of organic farm waste;
obtaining high-quality fertilisers to consequently increase crop yields
Goldstone mode of Skyrmion Crystal
We discuss the Goldstone mode of skyrmion crystal in a model of
two-dimenssional ferromagnet with Dzyaloshinskii-Moriya interaction in magnetic
field. We use stereographic projection approach to construct skyrmion crystal
and consider skyrmion's displacement field. The small overlap of the individual
skyrmion images restricts the potential energy to the interaction of nearest
neighboring displacements. The closed form of the Goldstone mode dispersion is
found and its dependence on the magnetic field is studied. We use semiclassical
quantization to define the Green's function and show that the propagation of
displacements through the crystal changes its tensorial form from isotropic to
anisotropic one at large distances.Comment: 6 pages, 4 figure
Generation of powerful terahertz emission in a beam-driven strong plasma turbulence
Generation of terahertz electromagnetic radiation due to coalescence of
upper-hybrid waves in the long-wavelength region of strong plasma turbulence
driven by a high-current relativistic electron beam in a magnetized plasma is
investigated. The width of frequency spectrum as well as angular
characteristics of this radiation for various values of plasma density and
turbulence energy are calculated using the simple theoretical model adequately
describing beam-plasma experiments at mirror traps. It is shown that the power
density of electromagnetic emission at the second harmonic of plasma frequency
in the terahertz range for these laboratory experiments can reach the level of
1 with 1% conversion efficiency of beam energy losses to
electromagnetic emission
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