МЕТОДИКА ПРОВЕДЕНИЯ ЭКСПЕРИМЕНТАЛЬНЫХ ИССЛЕДОВАНИЙ ПО ОПРЕДЕЛЕНИЮ МАССОВОЙ ДОЛИ ЭЛЕМЕНТОВ В СТАЛЯХ ПРИ ФОТОЭЛЕКТРИЧЕСКОМ СПЕКТРАЛЬНОМ МЕТОДЕ

Мethod for the measurement and selection of reference materials for photoelectric method of spectral analysis of steels (according ГОСТ 18 895) shows for research on atomic emission spectrometer DFS-71. Приведена методика проведений измерений и выбора стандартных образцов при фотоэлектрическом методе спектрального анализа состава сталей (в соответствии с ГОСТом 18895) при проведении исследований на атомно-эмиссионном спектрометре ДФС-71.

Analyzing the discharge regime of a large tropical river through remote sensing, ground-based climatic data, and modeling

This study demonstrates the potential for applying passive microwave satellite sensor data to infer the discharge dynamics of large river systems using the main stem Amazon as a test case. The methodology combines (1) interpolated ground-based meteorological station data, (2) horizontally and vertically polarized temperature differences (HVPTD) from the 37-GHz scanning multichannel microwave radiometer (SMMR) aboard the Nimbus 7 satellite, and (3) a calibrated water balance/water transport model (WBM/WTM). Monthly HVPTD values at 0.25° (latitude by longitude) resolution were resampled spatially and temporally to produce an enhanced HVPTD time series at 0.5° resolution for the period May 1979 through February 1985. Enhanced HVPTD values were regressed against monthly discharge derived from the WBM/WTM for each of 40 grid cells along the main stem over a calibration period from May 1979 to February 1983 to provide a spatially contiguous estimate of time-varying discharge. HVPTD-estimated flows generated for a validation period from March 1983 to February 1985 were found to be in good agreement with both observed arid modeled discharges over a 1400-km section of the main stem Amazon. This span of river is bounded downstream by a region of tidal influence and upstream by low sensor response associated with dense forest canopy. Both the WBM/WTM and HVPTD-derived flow rates reflect the significant impact of the 1982–1983 El Niño-;Southern Oscillation (ENSO) event on water balances within the drainage basin

ЭКСПЕРИМЕНТАЛЬНАЯ ОЦЕНКА ВЛИЯНИЯ РАЗЛИЧНЫХ МАСЕЛ, ВХОДЯЩИХ В СОСТАВ АЛМАЗНОЙ СУСПЕНЗИИ, НА АДГЕЗИЮ ПОЛУЧАЕМОГО АЛМАЗОСОДЕРЖАЩЕГО ПОКРЫТИЯ К ПОВЕРХНОСТИ РАСПИЛОВОЧНОГО ДИСКА

The paper contains an experimental estimation of influence rate of various oil being included in diamond suspension on adhesion of the obtained diamond-containing coating to cutting disk surface  which is applied for working a mono-crystal diamond.Статья посвящена экспериментальной оценке степени влияния различных видов масел, входящих в состав алмазной суспензии, на адгезию получаемого алмазосодержащего покрытия к поверхности распиловочного диска, применяемого для обработки монокристаллов алмаза

Экспресс-методы определения коэффициентов передаточных функций пароперегревательных участков котлов при различных нагрузках

The paper proposes rapid methods for transfer function coefficient determination of superheater sections under various loads while using a universal nomogram based on initial data of one load. The rapid methods make it possible to obtain analytical nonlinear dependences pertaining to changes of superheater transfer function parameters through the channel of regulatory impact, that provides parameter optimization of the dynamic knob injection adjustment throughout the whole range of power block load changes.Предложены экспресс-методы определения коэффициентов передаточных функций пароперегревательных участков при различных нагрузках с использованием универсальной номограммы на основе исходных данных одной нагрузки. Экспресс-методы дают возможность получить аналитические нелинейные зависимости изменения параметров передаточных функций пароперегервателей по каналу регулирующего воздействия, что позволяет оптимизировать параметры динамической настройки регуляторов впрысков во всем диапазоне изменения нагрузки энергоблоков

Multiwavelength Observations of the Blazar PKS 0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A

We report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.°2 away from the best-fit position of the IceCube neutrino event IceCube-211208A detected on 2021 December 8. The source was in a high-flux state in the optical, ultraviolet, X-ray, and GeV γ-ray bands around the time of the neutrino event, exhibiting daily variability in the soft X-ray flux. The X-ray data from Swift-XRT and NuSTAR characterize the transition between the low-energy and high-energy components of the broadband spectral energy distribution (SED), and the γ-ray data from Fermi-LAT, VERITAS, and H.E.S.S. require a spectral cutoff near 100 GeV. Both the X-ray and γ-ray measurements provide strong constraints on the leptonic and hadronic models. We analytically explore a synchrotron self-Compton model, an external Compton model, and a lepto-hadronic model. Models that are entirely based on internal photon fields face serious difficulties in matching the observed SED. The existence of an external photon field in the source would instead explain the observed γ-ray spectral cutoff in both the leptonic and lepto-hadronic models and allow a proton jet power that marginally agrees with the Eddington limit in the lepto-hadronic model. We show a numerical lepto-hadronic model with external target photons that reproduces the observed SED and is reasonably consistent with the neutrino event despite requiring a high jet power

Search for Ultraheavy Dark Matter from Observations of Dwarf Spheroidal Galaxies with VERITAS

Dark matter is a key piece of the current cosmological scenario, with weakly interacting massive particles (WIMPs) a leading dark matter candidate. WIMPs have not been detected in their conventional parameter space (100 GeV $\lesssim M_{\chi} \lesssim$ 100 TeV), a mass range accessible with current Imaging Atmospheric Cherenkov Telescopes. As ultraheavy dark matter (UHDM; $M_{\chi} \gtrsim$ 100 TeV) has been suggested as an under-explored alternative to the WIMP paradigm, we search for an indirect dark matter annihilation signal in a higher mass range (up to 30 PeV) with the VERITAS gamma-ray observatory. With 216 hours of observations of four dwarf spheroidal galaxies, we perform an unbinned likelihood analysis. We find no evidence of a $\gamma$-ray signal from UHDM annihilation above the background fluctuation for any individual dwarf galaxy nor for a joint-fit analysis, and consequently constrain the velocity-weighted annihilation cross section of UHDM for dark matter particle masses between 1 TeV and 30 PeV. We additionally set constraints on the allowed radius of a composite UHDM particle.Comment: 10 pages, 7 figure

A VERITAS/Breakthrough Listen Search for Optical Technosignatures

The Breakthrough Listen Initiative is conducting a program using multiple telescopes around the world to search for "technosignatures": artificial transmitters of extraterrestrial origin from beyond our solar system. The VERITAS Collaboration joined this program in 2018, and provides the capability to search for one particular technosignature: optical pulses of a few nanoseconds duration detectable over interstellar distances. We report here on the analysis and results of dedicated VERITAS observations of Breakthrough Listen targets conducted in 2019 and 2020 and of archival VERITAS data collected since 2012. Thirty hours of dedicated observations of 136 targets and 249 archival observations of 140 targets were analyzed and did not reveal any signals consistent with a technosignature. The results are used to place limits on the fraction of stars hosting transmitting civilizations. We also discuss the minimum-pulse sensitivity of our observations and present VERITAS observations of CALIOP: a space-based pulsed laser onboard the CALIPSO satellite. The detection of these pulses with VERITAS, using the analysis techniques developed for our technosignature search, allows a test of our analysis efficiency and serves as an important proof-of-principle.Comment: 15 pages, 7 figure

VERITAS discovery of very high energy gamma-ray emission from S3 1227+25 and multiwavelength observations

We report the detection of very high energy gamma-ray emission from the blazar S3 1227+25 (VER J1230+253) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). VERITAS observations of the source were triggered by the detection of a hard-spectrum GeV flare on May 15, 2015 with the Fermi-Large Area Telescope (LAT). A combined five-hour VERITAS exposure on May 16th and May 18th resulted in a strong 13$\sigma$ detection with a differential photon spectral index, $\Gamma$ = 3.8 $\pm$ 0.4, and a flux level at 9% of the Crab Nebula above 120 GeV. This also triggered target of opportunity observations with Swift, optical photometry, polarimetry and radio measurements, also presented in this work, in addition to the VERITAS and Fermi-LAT data. A temporal analysis of the gamma-ray flux during this period finds evidence of a shortest variability timescale of $\tau_{obs}$ = 6.2 $\pm$ 0.9 hours, indicating emission from compact regions within the jet, and the combined gamma-ray spectrum shows no strong evidence of a spectral cut-off. An investigation into correlations between the multiwavelength observations found evidence of optical and gamma-ray correlations, suggesting a single-zone model of emission. Finally, the multiwavelength spectral energy distribution is well described by a simple one-zone leptonic synchrotron self-Compton radiation model.Comment: 18 pages, 6 figures. Accepted for publication in the Astrophysical Journal (ApJ

EXPERIMENTAL TECHNIQUE FOR DETERMINATE OF MASS FRACTION OF ELEMENTS IN STEELS FOR PHOTOELECTRIC SPECTRAL METHOD

Мethod for the measurement and selection of reference materials for photoelectric method of spectral analysis of steels (according ГОСТ 18 895) shows for research on atomic emission spectrometer DFS-71