71 research outputs found
On gravitational interactions for massive higher spins in
In this paper we investigate gravitational interactions of massive higher
spin fields in three dimensional space with arbitrary value of
cosmological constant including flat Minkowski space. We use frame-like gauge
description for such massive fields adopted to three-dimensional case. At
first, we carefully analyze the procedure of switching on gravitational
interactions in the linear approximation on the example of massive spin-3 field
and then proceed with the generalization to the case of arbitrary integer spin
field. As a result we construct a cubic interaction vertex linear in spin-2
field and quadratic in higher spin field on background. As in the
massless case the vertex does not contain any higher derivative corrections to
the Lagrangian and/or gauge transformations. Thus, even after switching on
gravitational interactions, one can freely consider any massless or partially
massless limits as well as the flat one.Comment: 21 pages. Some clarifications and 1 new reference added. Version to
appear in the J.Phys.A special volume on "Higher Spin Theories and AdS/CFT"
edited by Matthias Gaberdiel and Mikhail Vasilie
FEATURES OF OPERATING MODES AND DISPATCHING CONTROL OF ISOLATED POWER SYSTEMS WITH DISTRIBUTED GENERATION
В статье рассмотрены основные задачи, решаемые при ведении режима в изолированной энергосистеме малой мощности. Приведены способы поддержания частоты и напряжения. Так же уделено внимание особенностям автоматических систем управления изолированными энергосистемами.The article describes the main problems solved in the management of the power system mode in an isolated grid with distributed generation. Methods for maintaining frequency and voltage level are given. Attention is also paid to the features of automatic control for isolated power systems
The impact of data filtration on the accuracy of multiple time-domain forecasting for photovoltaic power plants generation
The paper reports the forecasting model for multiple time-domain photovoltaic power plants, developed in response to the necessity of bad weather days’ accurate and robust power generation forecasting. We provide a brief description of the piloted short-term forecasting system and place under close scrutiny the main sources of photovoltaic power plants’ generation forecasting errors. The effectiveness of the empirical approach versus unsupervised learning was investigated in application to source data filtration in order to improve the power generation forecasting accuracy for unstable weather conditions. The k-nearest neighbors’ methodology was justified to be optimal for initial data filtration, based on the clusterization results, associated with peculiar weather and seasonal conditions. The photovoltaic power plants’ forecasting accuracy improvement was further investigated for a one hour-ahead time-domain. It was proved that operational forecasting could be implemented based on the results of short-term day-ahead forecast mismatches predictions, which form the basis for multiple time-domain integrated forecasting tools. After a comparison of multiple time series forecasting approaches, operational forecasting was realized based on the second-order autoregression function and applied to short-term forecasting errors with the resulting accuracy of 87%. In the concluding part of the article the authors from the points of view of computational efficiency and scalability proposed the hardware system composition. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
DYNAMICS MODEL OF THE CONTENT 131-I IN THE THYROID AND DAILY MILK YIELD IN DAIRY COWS
The model of radioiodine metabolism in the body of dairy cows, taking into account the content of stable iodine in the diet of animals, makes it possible to evaluate the effectiveness of the use of iodine preparations in order to reduce the accumulation of isotopes in the thyroid gland and milk
TEFLON-4 IN HIGH-DOSE EPR DOSIMETRY FOR ROUTINE MEASUREMENTS
In this work the possibility of using PTFE as a detector of dosimetric EPR-systems for control of radiation technologies is considered. A series of experimental results confirming the principal possibility of using PTFE-based detectors in high-dose dosimetry of ionizing radiation have been obtained.Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 20-38-90239
An approach to verification and validation of MHD codes for fusion applications
We propose a new activity on verification and validation (V&V) of MHD codes presently employed by the fusion community as a predictive capability tool for liquid metal cooling applications, such as liquid metal blankets. The important steps in the development of MHD codes starting from the 1970s are outlined first and then basic MHD codes, which are currently in use by designers of liquid breeder blankets, are reviewed. A benchmark database of five problems has been proposed to cover a wide range of MHD flows from laminar fully developed to turbulent flows, which are of interest for fusion applications: (A) 2D fully developed laminar steady MHD flow, (B) 3D laminar, steady developing MHD flow in a non-uniform magnetic field, (C) quasi-two-dimensional MHD turbulent flow, (D) 3D turbulent MHD flow, and (E) MHD flow with heat transfer (buoyant convection). Finally, we introduce important details of the proposed activities, such as basic V&V rules and schedule. The main goal of the present paper is to help in establishing an efficient V&V framework and to initiate benchmarking among interested parties. The comparison results computed by the codes against analytical solutions and trusted experimental and numerical data as well as code-to-code comparisons will be presented and analyzed in companion paper/paper
Solving the Noether procedure for cubic interactions of higher spins in (A)dS
The Noether procedure represents a perturbative scheme to construct all
possible consistent interactions starting from a given free theory. In this
note we describe how cubic interactions involving higher spins in any
constant-curvature background can be systematically derived within this
framework.Comment: 17 pages, LaTex. Invited contribution to the J. Phys. A special
volume on "Higher Spin Theories and AdS/CFT" edited by M. Gaberdiel and M. A.
Vasiliev. Final version to appear in J. Phys.
Groundwater Hydrogeochemical and Quality Appraisal for Agriculture Irrigation in Greenbelt Area, Iraq
This study highlights the groundwater hydrogeochemical characteristics and processes (hydrochemistry characteristics, ion exchange, and salinization) and quality suitability assessment for irrigation purposes from five wells in the Greenbelt area located in northwestern Al‐Najaf Gov-ernorate, Iraq. The suitability of groundwater for irrigation was assessed based on the irrigation water quality index (IWQI) for thirteen parameters and groundwater quality indices such as total dissolved solids (TDS), electrical conductivity (EC), sodium adsorption ratio (SAR), soluble sodium percent (SSP), residual sodium carbonate (RSC), total hardness (TH), permeability index (PI), potential salinity (PS), Kelley’s ratio (KR), and magnesium hazard ratio (MHR). The IWQI’s average values ranged between 76–139. The results of IWQI for the first and second sampling sites showed values of 139 and 104, respectively, indicating that the groundwater was unsuitable and unsafe for irrigation. In contrast, the IWQI for the third, fourth, and fifth sites were 83, 97, and 76, respectively, indicating that the groundwater was safe and possibly used for irrigation. The EC, TDS, PS, and MHR indices were all found to be unsuitable for irrigation in all five sites, and the KR index was also found to be unsuitable for agricultural irrigation in about 80% of the sites, while it was found that the indices of SAR, SSP, RSC, PI, and TH for all sites were suitable and safe for irrigation. As a result of this study, it has been determined that groundwater in the study area is unsuitable for agricultural irrigation. For sustainable groundwater exploitation, it is advised that a continuous water‐quality‐monitoring program should be implemented, as well as the development of suitable management practices. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
HYPERFINE INTERACTIONS IN IRON BORATE FeBO3
For the FeBO3 single crystal, the values of isomer shift, quadrupole constant and magnetic hyperfine field were determined for over a wide temperature range.Исследования выполнены при финансовой поддержке РФФИ, проект № 19-29-12016-мк, в части мёссбауэровских исследований и теоретического анализа. Рентгеновские измерения проведены при поддержке Министерства науки и высшего образования РФ в рамках выполнения работ по Государственному заданию ФНИЦ «Кристаллография и фотоника» с использованием оборудования ЦКП (проект RFMEFI62119X0035)
EFFECT OF THE GAS MEDIA AND TEMPERATURE REGIMES OF ANNEALING ON THE PHASE COMPOSITION OF IRON BORATE FeBO3
Iron borate FeBO3 crystals are annealed in neutral, oxidizing, and reducing gas media on a specially designed setup. The effect of the chemical medium and annealing modes on the surface morphology and phase composition of the samples is established.Исследования выполнены при финансовой поддержке РФФИ, проект № 19-29-12016-мк, в части разработки экспериментальной установки и получения кристаллических образцов. Рентгеновские и электронно-микроскопические измерения проведены при под-держке Министерства науки и высшего образования РФ в рамках выполнения работ по Государственному заданию ФНИЦ «Кристаллография и фотоника» с использованием оборудования ЦКП (проект RFMEFI62119X0035)
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