7,653 research outputs found
N=2 supersymmetric Yang-Mills theory and the superparticle: twistor transform and kappa-symmetry
Lagrangian and Hamiltonian dynamics of de Azcarraga-Lukierski N=2 massive
superparticle is considered in the framework of twistor-like Lorentz-harmonic
approach. The emphasis is on the study of the interaction with external Abelian
gauge superfield. The requirement of preservation of all gauge symmetries of
the free model including kappa-symmetry yields correct expressions for the
superfield strength constraints and determines the form of nonminimal
interaction. We also show that for de Azcarraga-Lukierski N=2 massive
superparticle the pullback of field strength 2-superform to the superworld line
is not integrable in contrast to the massless superparticle.Comment: 16 pages, LaTe
Effective application of mass balance method: case of organic fertiliser produced from pig slurry
Received: January 26th, 2021 ; Accepted: May 8th, 2021 ; Published: May 11th, 2021 ; Correspondence: [email protected] study aimed to verify the applicability of the mass balance method in calculating
quantity and quality of an organic fertiliser produced from unseparated pig slurry in a pigfattening complex in the Leningrad Region. The amount of manure at ex-animal level and its
nutrient content, required for further calculations of ex-housing manure and resulting organic
fertiliser at ex-storage, were calculated by applied diets and feed DM digestibility. Calculated
values were compared with the norms from relevant Russian regulatory documents. The
regulatory values of manure nitrogen were 22% smaller than the calculated ones. On the contrary,
the standard values of manure phosphorus and potassium exceeded the calculated ones by 72%
and 73%, respectively. The nutrient content of the organic fertiliser was calculated by the farm
data on pig housing and slurry processing systems. The values calculated by the mass balance
method were compared with those from the analysis reports issued by the certified laboratory.
The difference did not exceed 20%: 11.2% for N, 13.3% for P, and 18.7% for K. This way, the
mass balance method can be effectively used for calculating the characteristics of pig slurry-based
organic fertiliser. On the contrary, the data from the current regulatory manure management
documents showed the low reliability in the part of the physicochemical properties of fattening
pig manure. These documents do not take into account the changes in the fattening pig diets with
modern special concentrated feeds, which have a major effect on the manure nutrient content
Aerobic solid-state fermentation of the solid fraction of pig slurry
Current expansion in the pig number in Russia and their concentration in separate
locations contribute to higher environmental risks. One key risk factor is the slurry produced. To
utilize it more efficiently, many pig farms introduce its solid-liquid separation. The study
objective was to explore the feasibility of accelerated aerobic solid-state fermentation of the solid
fraction of pig slurry in closed installations. The stable thermophilic process under the
temperature above +55 °C achieves shorter processing time of 3–4 days. To date, however, there
is no representative evidence of such an experience. Four options of fermented mixture
composition were tested based on two types of the solid fraction of pig slurry: Type 1 fraction
coming from a screw separator and Type 2 fraction coming from a decanter centrifuge. The
fermenter operating modes were tested in the authors’ previous studies associated with processing
of the solid fraction of cattle manure and bedding poultry manure. The intensity measure of
fermentation was the temperature reached by the processed material in the fermenter. Under the
investigated operation modes, the stable temperature was observed for nine days in the mesophilic
process: 20 °С to 55 °С; in some cases, the transition to the thermophilic process – above 55 °С
was recorded. Adding the catalytic components to the processed material accelerated the substrate
self-heating and a higher temperature up to 59 °С was reached. This suggests that the considered
operating modes of the fermenter were suitable for the fermentation of the specified substrate
AdS_4 x CP^3 superstring and D=3 N=6 superconformal symmetry
Motivated by the isomorphism between osp(4|6) superalgebra and D=3 N=6
superconformal algebra we consider the superstring action on the AdS_4 x CP^3
background parametrized by D=3 N=6 super-Poincare and CP^3 coordinates
supplemented by the coordinates corresponoding to dilatation and superconformal
generators. It is also discussed the relation between the degeneracy of
fermionic equations of motion and the action kappa-invariance in the framework
of the supercoset approach.Comment: revtex, 12 pages. Version accepted to Phys. Rev. D; v4 corrected
misprints in Eqs.(65), (71); v5 corrected discussion of Z_4 grading on page
Variation in the mass and moisture content of solid organic waste originating from a pig complex during its fermentation
The focus of the study was the fermentation of an organic waste mixture originating
from a pig-rearing complex. The organic waste was processed in the laboratory-scale drum
fermenter. Through the fermentation process, the fermented material was weighed by a system
of four strain gauges installed under the fermenter. In our previous study, the following initial
mixture characteristics were justified to have the fermentation process going – 65% to 70%
moisture content and 400–600 kg m-3 density. The optimal operation mode of the fermenter was
identified depending on the initial mixture composition – aeration frequency of 5 min h-1
; air
consumption of 11.3 m3 h
-1 per 1.7 m3 of the fermenter volume; drum rotation interval – three
times every 12 hours. Under this operating mode, the mass loss was 3% already on the third
fermentation day and 7% – on the fifth day. As a result, the mass of the finished organic fertiliser
was 9% smaller than that of the loaded mixture. The moisture content of the processed material
also decreased: under the average moisture content of the loaded mixture of 68.7%, the average
moisture content of the organic fertiliser was 66.4%. Based on the resulting experimental data,
the mathematical models describing the dependence of the mass and moisture content of the
processed material on the fermentation time were created. The study outcomes allow concluding
that the solid-state aerobic fermentation is one of the promising options for the utilisation of the
solid fraction of pig slurry
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