61 research outputs found
Geant4 simulation study of low-Z material detection using muon tomography
Traditional X-ray scanning systems for cargo use ionising radiation which can be harmful to operators and the environment and requires shielding. Fully passive muon tomography is a promising alternative or a complementary approach to X-ray scanners. Muon tomography is a non-invasive technique that uses naturally occurring cosmic-ray muons and their scattering in various materials to create images of cargo in trucks or containers without applying ionising radiation. Muons are high-energy particles that are produced when primary cosmic rays collide with the Earth's atmosphere. These muons can penetrate through thick materials, such as concrete or metal, and are therefore useful for detecting hidden objects, including contraband. Muon tomography is expected to be used for detection of a wide range of materials, including metals, plastics, and organic materials like drugs or cigarettes, as well as weapons and explosives. In this work we have used the GEANT4 toolkit to simulate the performance of muon tomography in identifying the contraband hidden inside the legal cargo. We have used the Point of Closest Approach (PoCA) reconstruction algorithm to reconstruct the three-dimensional image of a loaded truck
THE PROCEDURE FOR THE PARTICIPATION OF SMALL BUSINESS ENTITIES-AGRICULTURAL PRODUCERS IN THE PUBLIC PROCUREMENT PROCESS
Background. Currently, agro-industrial holdings occupy a dominant position in Russia, which creates certain imbalances both in the agricultural and processing industries of the agro-industrial sector of the economy. In this connection, it is necessary to create conditions for the full functioning of SMP-agricultural producers. For this purpose, cooperation, conclusion of contracts or participation in state and municipal procurement can be used.
Purpose. Determination of the algorithm of participation of SMP-agricultural producers in the procurement process at the state and municipal levels. The work is theoretical in nature and is aimed at developing methodological approaches to the implementation of state and municipal purchases from agricultural producers.
Materials and methods. The study is based on legislative and regulatory acts and, at the same time, on the opinions of various authors on the problem of the participation of SMEs in the contract system of state and municipal procurement.
Results. In the course of the study, legislative and regulatory acts were considered in relation to procurement of various levels; an assessment of the participation of small businesses-agricultural producers in the field of public procurement was given; algorithms for the participation of this kind of entities in the procurement process were formed.
Conclusion. As a result, various aspects and features of the participation of small businesses in public procurement were identified
A Search for various Double Beta Decay Modes of Cd, Te and Zn Isotopes
Various double beta decay modes of Cd, Zn and Te isotopes are explored with
the help of CdTe and CdZnTe semiconductor detectors. The data set is splitted
in an energy range below 1 MeV having a statistics of 134.5 gd and one
above 1 MeV resulting in 532 gd. No signals were observed in all
channels under investigation. New improved limits for the neutrinoless double
beta decay of Zn70 of (90% CL), the longest
standing limit of all double beta isotopes, and 0EC of Te120 of
(90% CL) are given. For the first time a
limit on the half-life of the 2ECEC of Te of (90% CL) is obtained. In addition, limits on 2ECEC for ground
state transitions of Cd106, Cd108 and Zn64 are improved. The obtained results
even under rough background conditions show the reliability of CdTe
semiconductor detectors for rare nuclear decay searches.Comment: Extended introduction and summar
Two neutrino positron double beta decay of Cd for transition
The two neutrino positron double beta decay of Cd for 0
0 transition has been studied in the Hartree-Fock-Bogoliubov model in
conjunction with the summation method. In the first step, the reliability of
the intrinsic wave functions of Cd and Pd nuclei has been
tested by comparing the theoretically calculated results for yrast spectra,
reduced : transition probabilities, quadrupole moments
and gyromagnetic factors with the available experimental
data. In the second step, the nuclear transition matrix element and
the half-life for 0 0 transition have been
calculated with these wave functions. Moreover, we have studied the effect of
deformation on nuclear transition matrix element MComment: 20 page
On the alpha activity of natural tungsten isotopes
The indication for the alpha decay of 180-W with a half-life
T1/2=1.1+0.8-0.4(stat)+-0.3(syst)x10^18 yr has been observed for the first time
with the help of the super-low background 116-CdWO_4 crystal scintillators. In
conservative approach the lower limit on half-life of 180-W has been
established as T1/2>0.7x10^18 yr at 90% C.L. Besides, new T1/2 bounds were set
for alpha decay of 182-W, 183-W, 184-W and 186-W at the level of 10^20 yr.Comment: 16 pages, 8 figures, accepted in Phys. Rev.
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