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The paper describes the calculation and design steps of deep excavations and foundations of a high-rise building on a territory with a high groundwater level and existing buildings with a physical wear of their bearing structures and foundations located in the zone of mutual influence. The aim is to find a rational solution for the diaphragm wall, pile-raft foundation of the high-rise building in order to protect adjacent objects and consider various factors that determine the nonlinear behavior of subsoil layers and the elements of geotechnical protection. As an example, a project of a high-rise building with a multi-level underground parking located in the central part of Krasnodar is shown. It is designed and calculated considering the staged construction of the pile-raft foundation, non-linear behavior of the subsoil layers, the influence of a variable groundwater level, the risk of technological settlements and liquefaction of the underlying sandy soil layers. Due to the performed researches and by following the construction methods, it became possible to keep the existing buildings and structures safe during the construction period and further operations. The observed methods of construction of the pile-raft foundations and deep excavations in difficult subsoil conditions using the example of the central part of Krasnodar make it possible to recommend the obtained results as a rational solution applicable for similar cases in conditions of a dense urban infrastructure.

UHECR propagation in a turbulent intergalactic magnetic field in the small-angle scattering regime is well understood for propagation distances much larger than the field coherence scale. The diffusion theory doesn’t work and unexpected effects may appear for propagation over smaller distances, from a few and up to 10–20 coherence scales. We study the propagation of UHECRs in this regime, which may be relevant for intermediate mass UHECR nuclei and nG scale intergalactic magnetic fields with 1 Mpc coherence scale. We found that the trajectories form a non-trivial caustic-like pattern with strong deviation from isotropy. Thus, measurements of the flux from a source at a given distance will depend on the position of the observer.

A new scenario for creation of galactic magnetic fields is proposed which is operative at the cosmological epoch of the galaxy formation, and which relies on unconventional properties of dark matter. Namely, it requires existence of feeble but long range interaction between the dark matter particles and electrons. In particular, millicharged dark matter particles or mirror particles with the photon kinetic mixing to the usual photon can be considered. We show that in rotating protogalaxies circular electric currents can be generated by the interactions of free electrons with dark matter particles in the halo, while the impact of such interactions on galactic protons is considerably weaker. The induced currents may be strong enough to create the observed magnetic fields on the galaxy scales with the help of moderate dynamo amplification. In addition, the angular momentum transfer from the rotating gas to dark matter component could change the dark matter profile and formation of cusps at galactic centers would be inhibited. The global motion of the ionized gas could produce sufficiently large magnetic fields also in filaments and galaxy clusters.

In this work we present a keV-scale sterile-neutrino search with a low-tritium-activity data set of the KATRIN experiment, acquired in a commissioning run in 2018. KATRIN performs a spectroscopic measurement of the tritium β -decay spectrum with the main goal of directly determining the effective electron anti-neutrino mass. During this commissioning phase a lower tritium activity facilitated the measurement of a wider part of the tritium spectrum and thus the search for sterile neutrinos with a mass of up to 1.6 keV . We do not find a signal and set an exclusion limit on the sterile-to-active mixing amplitude of sin 2 θ < 5 × 10 - 4 ( 95 % C.L.) at a mass of 0.3 keV. This result improves current laboratory-based bounds in the sterile-neutrino mass range between 0.1 and 1.0 keV.

In this paper, we present the first high‐speed video observation of a cloud‐to‐ground lightning flash and its associated downward‐directed Terrestrial Gamma‐ray Flash (TGF). The optical emission of the event was observed by a high‐speed video camera running at 40,000 frames per second in conjunction with the Telescope Array Surface Detector, Lightning Mapping Array, interferometer, electric‐field fast antenna, and the National Lightning Detection Network. The cloud‐to‐ground flash associated with the observed TGF was formed by a fast downward leader followed by a very intense return stroke peak current of −154 kA. The TGF occurred while the downward leader was below cloud base, and even when it was halfway in its propagation to ground. The suite of gamma‐ray and lightning instruments, timing resolution, and source proximity offer us detailed information and therefore a unique look at the TGF phenomena. Plain Language Summary This study provides the very first simultaneous observations of a downward‐directed terrestrial gamma‐ray flash (TGF) together with its associated cloud‐to‐ground lightning flash using a high‐speed camera in addition to gamma‐ray and radio measurements. The camera, running at 40,000 frames per second, allowed us to check the characteristics of the downward leader, the development stage of the lightning flash, and the luminosity variations in coincidence with TGF production. Key Points Simultaneous recordings of a downward‐directed terrestrial gamma‐ray flash (TGF), high‐speed video images, and radio emissions TGF events occurred while the leader was already branching below cloud base and even when it was halfway in its propagation to ground Energetic downward‐directed TGFs were associated with fast downward leaders that produced high return stroke peak currents

Due to the unusual architectural forms of modern high-rise buildings, as well as an increase in design loads on their bases, geotechnics is developing. Experts in the field of bases and foundations solve increasingly complicated problems, as a result of which methods for calculating, designing and building hidden from the eyes, but very responsible and costly elements of the buildings that are the foundations, are improved. Hazardous natural processes, high seismicity, the risk of developing landslide processes complicate the task and make the problem of foundation engineering in such conditions even more urgent. The methods being developed for the construction of effective foundations have made it possible to erecting a number of high-rise buildings in seismic areas in recent years.

Solving of the light scattering problem of atmospheric ice crystals is necessary for interpreting data of laser sensing of the atmosphere. Light backscattering matrices for cloud ice crystals of arbitrary form of 10 to 300 μm in size with the number of faces of 15, 20, and 40 are calculated within the physical optics approximation for the case of arbitrary spatial orientation of particles and single scattering of light at wavelengths of 0.532 and 1.064 μm. According to the statistical analysis of crystals, their optical properties slightly differ. Optical properties of an etalon particle taken from the IAO SB RAS data bank are shown to satisfy the above distribution, thus confirming the validity of using the database for the case of a large set of particles with the number of faces from 15 to 40. The results are necessary for constructing algorithms for interrelating data of lidar sensing of cirrus clouds.

We present the results of measuring intensity variations of atmospheric emission in the 630, 557.7, and 391.4 nm lines, caused by the impact of high-power short-wave radio emission of the Sura heating facility on the ionosphere. The data were obtained using a three-channel photometer located in the immediate vicinity of the heater. In the experiments of 2023 and 2024, a regular increase in the emission intensity in the 391.4 and 557.7 nm lines, induced by the Sura radiation, was recorded for the first time.

The KATRIN experiment is designed for a direct and model-independent determination of the effective electron anti-neutrino mass via a high-precision measurement of the tritium β-decay endpoint region with a sensitivity on mν of 0.2 eV/c2 (90% CL). For this purpose, the β-electrons from a high-luminosity windowless gaseous tritium source traversing an electrostatic retarding spectrometer are counted to obtain an integral spectrum around the endpoint energy of 18.6 keV. A dominant systematic effect of the response of the experimental setup is the energy loss of β-electrons from elastic and inelastic scattering off tritium molecules within the source. We determined the energy-loss function in-situ with a pulsed angular-selective and monoenergetic photoelectron source at various tritium-source densities. The data was recorded in integral and differential modes; the latter was achieved by using a novel time-of-flight technique. We developed a semi-empirical parametrization for the energy-loss function for the scattering of 18.6-keV electrons from hydrogen isotopologs. This model was fit to measurement data with a 95% T2 gas mixture at 30 K, as used in the first KATRIN neutrino-mass analyses, as well as a D2 gas mixture of 96% purity used in KATRIN commissioning runs. The achieved precision on the energy-loss function has abated the corresponding uncertainty of σ(mν2)<10-2eV2 [1] in the KATRIN neutrino-mass measurement to a subdominant level.

The KATRIN experiment aims to measure the effective electron antineutrino mass \\[m_{\\overline{\\nu }_e}\\] with a sensitivity of \\[{0.2}\\,{\\hbox {eV}/\\hbox {c}^2}\\] using a gaseous tritium source combined with the MAC-E filter technique. A low background rate is crucial to achieving the proposed sensitivity, and dedicated measurements have been performed to study possible sources of background electrons. In this work, we test the hypothesis that gamma radiation from external radioactive sources significantly increases the rate of background events created in the main spectrometer (MS) and observed in the focal-plane detector. Using detailed simulations of the gamma flux in the experimental hall, combined with a series of experimental tests that artificially increased or decreased the local gamma flux to the MS, we set an upper limit of \\[{0.006}\\,{\\hbox {count}/\\hbox {s}}\\] (90% C.L.) from this mechanism. Our results indicate the effectiveness of the electrostatic and magnetic shielding used to block secondary electrons emitted from the inner surface of the MS.