Methods for forming an irrigation network for a mole subsurface irrigation system

The article presents the results of field studies carried out in 2022 on light chestnut soils of the Lower Volga region, which were aimed at studying the methods of forming soil pipes for the mole irrigation system using various designs of the mole tine (a special working body for cutting molehills) and the speed of the tractor during the formation of the irrigation network. The considered method of irrigation in the soil and climatic conditions of this region has not been previously studied. As a result, it was found that the use of a trapezoidal stand with a “knife” (a front cutting edge 30 mm wide along the entire height of the stand) and a “chisel” (a rectangular cutting surface of the drainer) was the most effective for arranging an irrigation network of mole irrigators (molehills), since here, regardless of the shape and size of the expanders, the degree of their shedding was 5–38% lower than in the variants with a rectangular post with an ellipsoid shape of the cutting surface of the drainer. Also, our studies showed that when the tractor was moving at 0.9 ... 2.6 km / h, the degree of destruction of molehills was 42 ... 87%, and at 3.4 ... 4.3 km / h this figure decreased to 13 ... 18%, therefore, this speed allowed more efficient formation of soil pipes for the creation of mole subsoil irrigation systems. The study was supported by a grant from the Russian Science Foundation and the Administration of the Volgograd Region under project No. 22-26-20070, https://rscf.ru/project/22-26-20070

Determination of the main parameters of the mole irrigation network in the Lower Volga region

The article presents the results of studies to determine the main parameters of the irrigation network for the mole irrigation system on light chestnut soils of the Volgograd region, a typical region of the Lower Volga region. This method of irrigating crops will be used for the first time in this region. For this, 3 variants of the depth (0.3; 0.4 and 0.5 m) of the location of mole sprinklers - soil pipes with a diameter of 58 ... 63 mm for supplying water to plants were studied. Based on the study of moisture contours, it was found that the most effective was the location of molehills at a depth of 0.3 ... 0.4 m, since 99.3 ... 95.1% of the moisture in the zone of normal moistening (90…110% SMC the next day after watering) was within the active soil layer of 0.0-0.8 m in the absence of deep filtration into the underlying layers. Further study of the moisture contours showed that at a mole irrigation depth of 0.3…0.5 m, the zone of normal moisture (90…110% SMC) extended 40…51 cm to the left and 42…45 cm to the right, and the zone of low moisture (75 ...90% SMC) - 69...91 cm to the left and 63...68 cm to the right of the molehill axis, which allows soil sprinklers to be located at a distance of 1.0...1.5 m from each other if it is necessary to uniformly moisten the active soil layer throughout the irrigation area. The study was supported by a grant from the Russian Science Foundation and the Administration of the Volgograd Region under project No. 22-26-20070, https://rscf.ru/project/22-26-20070

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Constraints on the galactic magnetic field with two-point cumulative autocorrelation function

2012 Spring.Includes bibliographical references.The fact that ultra high energy cosmic rays are charged particles complicates identication of their sources due to deflections by the intervening cosmic magnetic fields. The information about the fields is encoded in the amount of deflection experienced by a charged particle. Unfortunately, the positions of sources are unknown as is the structure of the magnetic field. However, it is possible to deduce the most favorable galactic magnetic field by examining the parameter space of different models of the galactic magnetic field. The method presented in this work is valid under some plausible assumptions, such as extragalactic origin of the UHECR, pure protonic composition above 50 EeV and sufficiently weak randomly oriented galactic and extragalactic components of the magnetic field. I use a two point cumulative autocorrelation function combined with the backtracking method to find regions in the parameter space that are compatible with statistically significant clustering on the extragalactic sky. This approach is independent of any catalog of sources. The ratio between the number of pairs within a certain angular window at the Earth sky and at the extragalactic sky after backtracking serves to indicate focusing or de-focusing properties of a particular field configuration. The results suggest that among several tested fields, the Harari-Mollerach-Roulet model with a bi-symmetric spiral and even vertical symmetry favors clustering of arrival directions at the extragalactic sky with the probability of 2.5% being from an isotropic distribution. Addition of the toroidal halo field improves clustering for the Harari-Mollerach-Roulet field for both bi-symmetric and axisymmetric spirals with even vertical symmetry, and the isotropic probabilities are 2.5% and 5.3% correspondingly. The bi-symmetric and axisymmetric spirals with odd vertical symmetry are disfavored, as well as the models with annular structure

Determination of the main parameters of the mole irrigation network in the Lower Volga region

The article presents the results of studies to determine the main parameters of the irrigation network for the mole irrigation system on light chestnut soils of the Volgograd region, a typical region of the Lower Volga region. This method of irrigating crops will be used for the first time in this region. For this, 3 variants of the depth (0.3; 0.4 and 0.5 m) of the location of mole sprinklers - soil pipes with a diameter of 58 ... 63 mm for supplying water to plants were studied. Based on the study of moisture contours, it was found that the most effective was the location of molehills at a depth of 0.3 ... 0.4 m, since 99.3 ... 95.1% of the moisture in the zone of normal moistening (90…110% SMC the next day after watering) was within the active soil layer of 0.0-0.8 m in the absence of deep filtration into the underlying layers. Further study of the moisture contours showed that at a mole irrigation depth of 0.3…0.5 m, the zone of normal moisture (90…110% SMC) extended 40…51 cm to the left and 42…45 cm to the right, and the zone of low moisture (75 ...90% SMC) - 69...91 cm to the left and 63...68 cm to the right of the molehill axis, which allows soil sprinklers to be located at a distance of 1.0...1.5 m from each other if it is necessary to uniformly moisten the active soil layer throughout the irrigation area. The study was supported by a grant from the Russian Science Foundation and the Administration of the Volgograd Region under project No. 22-26-20070, https://rscf.ru/project/22-26-2007

Methods for forming an irrigation network for a mole subsurface irrigation system

The article presents the results of field studies carried out in 2022 on light chestnut soils of the Lower Volga region, which were aimed at studying the methods of forming soil pipes for the mole irrigation system using various designs of the mole tine (a special working body for cutting molehills) and the speed of the tractor during the formation of the irrigation network. The considered method of irrigation in the soil and climatic conditions of this region has not been previously studied. As a result, it was found that the use of a trapezoidal stand with a “knife” (a front cutting edge 30 mm wide along the entire height of the stand) and a “chisel” (a rectangular cutting surface of the drainer) was the most effective for arranging an irrigation network of mole irrigators (molehills), since here, regardless of the shape and size of the expanders, the degree of their shedding was 5–38% lower than in the variants with a rectangular post with an ellipsoid shape of the cutting surface of the drainer. Also, our studies showed that when the tractor was moving at 0.9 ... 2.6 km / h, the degree of destruction of molehills was 42 ... 87%, and at 3.4 ... 4.3 km / h this figure decreased to 13 ... 18%, therefore, this speed allowed more efficient formation of soil pipes for the creation of mole subsoil irrigation systems. The study was supported by a grant from the Russian Science Foundation and the Administration of the Volgograd Region under project No. 22-26-20070, https://rscf.ru/project/22-26-20070