bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining River Absorption Capacity Using Simple Mathematical Model: A Case Study in Palur River, Sukoharjo Regency, Central Java Province, Indonesia
Authors: Nugraha Setya , Purnawan Candra , Rizki Muhammad Habib 
Published: February 2022

Abstract
The increase in population causes a decrease in the quality of river water. Rivers are the most vulnerable ecosystem due to human activities. Humans throw the results of daily activities into rivers both from agricultural activities, domestic waste, and industrial activities. This waste results in a decrease in the quality of river water. Therefore the river needs to be managed properly. One of the efforts to manage the river is to determine the absorption capacity of the river itself. However, not many studies have been conducted regarding the absorption capacity of rivers, especially in small rivers. This study aims to determine the absorption capacity of the Palur River using a simple mathematical model called the Mass Balance (Neraca Massa). The results of calculations using the Mass Balance model obtained the average concentration value (Cr) from each segment of the Palur River. The worst river segment is Segment II with an average concentration (Cr) of TSS 54.22 mg/L, BOD 8.12 mg/L, and COD 26.21 mg/L. The calculation results show that the Palur River Segment II no longer has the capacity for TSS, BOD, and COD parameters. Waste that is dumped directly into the river needs to be processed first so that the load entering the river meets quality standards. Furthermore, it is hoped that the results of this study can be used as the first step in efforts to control water river pollution.
Ensuring of reliability and security of energy systems in the Russian Federation
Authors: Barykina Y N , Chernykh A G 
Published: February 2022

Abstract
Shutdown for maintenance of generating equipment is crucial when planning repairs. In the analysis of this issue, it is necessary to understand the nature of the problem and find ways to solve it. It is necessary to define the concept of reliability in general and reliability of power systems in particular. The article examines electric power systems, their properties and elements. The relationship between functions and properties of energy systems is analyzed, and the main functions (associated with operation of generating equipment and its production) are described. The concept of function means that the object has a task that is being performed. In turn, fulfillment or non-fulfillment of the task is related to the concept of reliability. Reliability is a property of an object to perform a given function associated with its purpose, accounting for the given constraints
Use of a depressant-dispersant additive during storage of diesel fuel
Authors: Iovleva E L 
Published: February 2022

Abstract
The problem of long-term storage of fuel remains relevant for the sparsely populated and inaccessible regions of the Arctic and Priakticheskoy zones. To ensure the heating season, lasting 9-11 months, it is necessary to import diesel fuel during the summer period during navigation, since in winter there is no access to the regions of the North by land. By the decision of the government, large volumes of diesel fuel are imported under the programs for the provision of the northern and arctic regions, so 740 thousand tons of fuel was imported to the Republic of Sakha (Yakutia) in 2020. This amount of fuel is not assimilated in one season and this fuel is stored in tanks. Where, during long-term storage, the quality of raw materials deteriorates. During long-term storage of fuel, depressants do not prevent fuel stratification. Therefore, together with a depressant additive, a paraffin dispersant is used; the composition of such additives includes mainly amides and imides of mono- and dicarboxylic acids. In this article, we have studied the effect of the Dewaxol depressant-dispersant additive on diesel fuel. Considered how at various concentrations and heating temperatures of the fuel, the cloud point decreases and sedimentation stability improves. As a result of the study, it was found that the best sedimentation stability is possessed by a fuel with a high content of a depressant-dispersant additive. In addition, fuel with an additive concentration of 0.1 wt% has the maximum depressant effect and heated to 60 °C.
Distribution network section reliability analysis based on the semi-Markov model
Authors: Sidorov S M , Lugovkin A S 
Published: February 2022

Abstract
The digital training ground of Sevastopol State University (SevSU) is a physical model of a section of an intelligent distribution network of a new generation. In this article, a semi-Markov model of the distribution network section of the SevGU digital training ground is built. The reliability stationary characteristics of the considered section of the network are determined, two cases of consumer nutrition are considered. A numerical example of finding the reliability stationary characteristics using the obtained in the article formulas is given. The obtained results make it possible to analyze the reliability and efficiency of the distribution network sections.
Flow in a channel with porous insert
Authors: Rasulov A , Dalabaev U 
Published: February 2022

Abstract
Filtration of an incompressible liquid (gas) in a non-deformable porou s medium is investigated. The results of numerical simulation of the hydrodynamic features of the flow arising after the passage of the liquid through a layer of an immobile porous medium are presented. An interpenetrating model of multiphase media is used to describe such flows. The porosity and permeability of the porous medium, as well as the force of interfacial interaction, are considered in the framework of compliance with the Kozeny-Karman ratio. The influence of the geometrical shape of the bulk layer on the nature and magnitude of the inhomogeneity of the flow velocity behind the obstacle is shown. Considering the shape of the porous medium significantly affects the flow parameters. Numerical simulation results are compared with experimental data. The effects of the non-uniformity of the fluid velocity field arising from the curvature of the layer surface and the influence of the arising inhomogeneity on the velocity are investigated by the methods of a computational experiment. A qualitative comparison is made of velocity inhomogeneities when a fluid flows through a porous obstacle. For the numerical implementation of the filtration equation of the interpenetrating model, a SIMPLElike algorithm was used.
Mathematical model of optimization of repair activities of power equipment
Authors: Shamraeva V V , Kalinin V M , Morkovkin D E , Koryakov A G , Zakharova M V , Perfilyev A A 
Published: February 2022

Abstract
The tasks related to the efficient operation and maintenance of the power equipment in a working condition are considered. In the work, a model is built and a method is proposed for optimizing the intensity of performance indicators, which does not take into account the structure and with instant indexing of failure. At this stage, a lower estimate is obtained for the minimum average unit costs, taking into account the residual resource of the elements of such a system. This makes it possible to provide the required level of emergency repair frequency. The collection and accumulation of such information is in demand when planning subsequent preventive restorations of elements and equipment of electric power enterprises.
Installation for experimental research of thermal and hydraulic processes of hybrid power systems of high power transmission
Authors: Firsov V P , Antyukhov I V , Yakovlev A A , Golovanov D F 
Published: February 2022

Abstract
An installation for experimental research of thermal and hydraulic processes in hybrid high-power energy transmission systems is considered, in which an increase in power transmission and energy flux density is achieved by the simultaneous transportation of liquid hydrogen or LNG (liquefied natural gas) and in electrical form - using a superconducting cable.
Simulation of the operation of the solar panel of the pilot plant in the Ansys software package
Authors: Moiseev I A , Shishkov A N , Berseneva I A , Osintzev K V 
Published: February 2022

Abstract
The article presents the results of the calculation of the thermal parameters of the solar battery of the pilot plant, performed using the ANSYS program. To analyze the influence of various parameters on the efficiency of the solar battery, when setting data in the preprocessor, such parameters as density, thermal conductivity coefficients, and element sizes were varied. Environmental factors were also analyzed, namely, ambient temperature and heat flow. For the developed installation, the choice of training a neural network without a teacher is justified. The results of calculations are presented in the form of graphs and tables, as well as illustrations of the fields of temperature distribution and heat flow.
Robust-adaptive method of power unit control based on the operational assessment of fuel quality indicators
Authors: Safiullin Ravil , Safiullin Ruslan , Reznichenko Victor , Epishkin Alexander , Gorlatov Dmitriy 
Published: February 2022

Abstract
The article develops systems for the operational assessment of fuel quality indicators, schematic diagrams of sensors, evaluation criteria that allow: to provide the desired values of indicators for the operational assessment and implementation of operational properties of the types of fuel used that determine the quality of the power unit, such as fuel efficiency, emissions of harmful substances, noise level; to identify the main factors at all stages of the transportation process. The article presents the results of a study on the formation of a robust adaptive control method of a power unit based on the developed systems, schemes and evaluation criteria. In order to optimize the control system of the power unit, a three-level information and control model of the fuel quality assessment system on the vehicle has been developed. As a criterion of optimality in terms of the quality of the fuel used, the developed fuel utilization factor of the power unit was used.
Assessing the degree of coal tectonic disturbance by multifractal analysis of scanning electron microscopy images of coal specimen surfaces
Authors: Uchaev Dm V , Uchaev D V , Malinnikova O N 
Published: February 2022

Abstract
The application of a multifractal approach to assessing the degree of coal disturbance is shown using a series of 2D model configurations of coals and scanning electron microscopy (SEM) images of coal specimen surfaces. For this, multifractal spectra, also called multifractal signatures, are used, which are suitable for a comprehensive description of the structural organization of the surface of coals with different degrees of disturbance. It is shown that maximum values of the multifractal signatures can be used to assess the degree of coal disturbance, and higher values of the parameters are obtained for coal specimens taken from more disturbed coal seams. As a result of the study, six coal disturbance classes have been identified, corresponding to the disturbance classes for model coal configurations generated for the following disturbance threshold values: 3/9, 4/9, 5/9, 6/9, 7/9 и 8/9.
Technical and economic optimization of the hydrogen-thermal energy storage at nuclear power plant
Authors: Egorov A N , Yurin V E , Bairamov A N 
Published: February 2022

AbstractThe article discusses and optimizes the system developed by the authors based on closed-cycle hydrogen-thermal storage using external and built-in hydrogen-oxygen steam generator. On the basis of the finite element method with the use of the ANSYS software package, the process of starting up and entering the operating mode of the steam generator was simulated. The distribution dynamics of temperature fields and thermomechanical stresses in the walls of the combustion chamber are shown. When using the built-in combustion chamber, the maximum wall temperature after reaching the operating mode was 391°C and for 179°C for the external combustion chamber. The distribution dynamics of thermomechanical stresses fields practically corresponds to the distribution dynamics of temperature fields. In this case, the thermomechanical stresses for the built-in combustion chamber amounted to 219MPa, for the external – 195MPa. Taking into account the estimation of the calculated lifetime, an optimization technical and economic analysis of the efficiency implementation of hydrogen-oxygen steam generator was carried out. The use of built-in hydrogen-oxygen steam generator makes it possible to increase the efficiency of off-peak electricity use by 14.76% and to reduce the cost of peak electricity production by 18.4%, taking into account the lifetime.
Comparative analysis of lithological and geochemical features and conditions for the formation of oil and gas source rock strata
Authors: Zakharova N S , Morozov V P , Eskin A A , Kolchugin A N , Khayuzkin A S 
Published: February 2022

Abstract
The typification according to the lithological and geochemical characteristics of the deposits that make up the sections of the two oil source strata: Domanik and Bazhen was carried out . Lithotypes are revealed. For each of the objects of study, a complex of laboratory studies of rocks and contained fluids was carried out. The relationships were revealed between the mineral composition of rocks, the content and types of contained organic matter, the degree of organic matter maturity,the chemical composition of the inorganic and component composition of the organic parts of study strata.
Methodological approaches to assessing the toxicity of compounds by changing the behavioral response of soil oligochaetes
Authors: Stom D I , Gelman M M , Antonova E V , Lozovaya T S , Stom A D 
Published: February 2022

Abstract
The methodological aspects of assessing the toxicity of surface-active substances (SAS) by changing the behavioral response of avoiding the substrate by earthworms Eisenia fetida andrei Bouche, 1972 were studied. The conditions for biotesting were selected, under which the method is more sensitive to the tested pollutants. In this method, 30 worms. placed in a Petri dish with a substrate unfavorable for worms (dry sand). Around it, Petri dishes with test samples of moistened sand contaminated with individual toxicants in various concentrations and their mixtures were placed radially. A control sample (wet sand) was also placed among the prototypes. When the worms selected the most favorable of the tested contaminated substrate samples, their movement from dry sand was observed. After 4 h from the start of the experiment, the number of worms in each of the compartments was counted. The toxic effect of the cationic surfactant cetyltrimethylammonium bromide (CTAB) was manifested when its content in the soil sample was from 0.001 g / kg; nonionic surfactant Tween-80 – from 1 ml / kg; anionic surfactant sodium lauryl sulfate – from 20 mg / kg.
Changes in the number and intensity of sorption of Micrococcus luteus on carbon fiber at different degrees of its polarization
Authors: Yu Konovalova E , Khorina N N , Saksonov M N , Stom D I , Yu Tolstoy M 
Published: February 2022

Abstract
The electrogenic activity of many microorganisms used in MFC is due to direct electron transfer. It is achieved by direct contact of microbial cells with an electrode. In this regard, an important aspect of research in the field of MFC is the study of the interaction of electrogenic microorganisms with electrode materials. In this work, the influence of polarization of carbon fiber from an external source of electrical energy on the intensity of sorption on it of cells of the electrogenic strain Micrococcus luteus 1-i is considered. It was shown that the polarization of carbon fiber 0.6-0.8 V positively influenced the sorption of cells of the electrogenic strain M. luteus 1-i, and 0.4-0.6 V positively influenced the increase in the number of cells of the strain. The preliminary application of a voltage of 0.6 V to the MFC anode for 2 h led to an increase in the current generated by the M. luteus strain 1 within a 24hour experiment. The obtained positive effect demonstrates the possibility of using this approach to increase the efficiency of the MFC technology.
Bridge role of weak chemical bonding in photocatalytic performance of asymmetric 2H-MoS2/BiOCl Janus heterostructure
Authors: Xu Te-Te , Zhao Pan , Jiang Zhen-Yi , Zheng Ji-Ming , Lin Yan-Ming 
Published: February 2022

Abstract
The geometric and electronic structure, partial (band decomposed) charge density, charge transfer, electron localization function and photocatalytic mechanism of the asymmetric 2H-MoS2/BiOCl Janus heterostructure were systematically studied with first-principles density functional theory. Our calculations showed that there exist several newly formed weak Bi-S bonds with shorter bond lengths between BiOCl and 2H-MoS2 which act as an electron transport bridge along the direction perpendicular to the heterojunction interface. This newly weak bonds lead to the formation of occupied shallow defect levels approximately 0.0–0.9 eV below the bottom of the conduction band. Electrons located at these defect levels can easily jump into the conduction band as a donor energy level under thermal fluctuations and simultaneously further promote the effective separation of photo-generated electron-hole pairs in the BiOCl. The photogenerated electrons located around Bi-atom layer in the conduction band of BiOCl transfer to the valence band of 2H-MoS2 around the S-atom layer through the interface of the asymmetric 2H-MoS2/BiOCl Janus heterostructure, which significantly reduce photo-generated holes in the 2H-MoS2 and electrons in the BiOCl. The large numbers of photogenerated electrons from the 2H-MoS2 cannot recombine with holes owing to lack of sufficient holes. They will move to the surface and greatly improve the hydrogen production activity in the 2H-MoS2. While the photogenerated holes from the BiOCl will significantly improve the ability of BiOCl to oxidize pollutant in the water owing to the absence of sufficient electrons. Our studies provide new way for the design of asymmetric Janus double-layer heterostructures with newly formed weak chemical bonding.
Towards an approach of disability along a continuum from robustness, pre-frailty, frailty to disability
Authors: Zamudio-Rodríguez Alfonso , Avila-Funes José Alberto , Tabue-Teguo Maturin , Dartigues Jean-François , Amieva Hélène , Pérès Karine 
Published: February 2022

Abstract

Background
frailty and disability are very prevalent in older age and although both are distinct clinical entities, they are commonly used indistinctly in order to identify vulnerable older adults.

Objective
to propose a hierarchical indicator between frailty and disability among older adults along a single continuum.

Design
population-based cohort study.

Setting
the Bordeaux Three-City Study and the Aging Multidisciplinary Investigation (AMI) cohort.

Subjects
the sample included 1800 participants aged 65 and older.

Methods
an additive hierarchical indicator was proposed by combining the phenotype of frailty (robustness, pre-frailty and frailty), instrumental activities of daily living (IADL) and basic activities of daily living (ADL). To test the relevance of this indicator, we estimated the 4-year mortality risk associated with each stage of the indicator.

Results
in total, 34.0% were Robust (n = 612), 29.9% were Pre-frail (n = 538), 3.2% were Robust with IADL-disability (n = 58), 4.6% had pure Frailty (no disability) (n = 82), 11.9% were Pre-frail + IADL (n = 215), 8.6% were Frail + IADL (n = 154) and 7.8% Frail + IADL + ADL (n = 141). After grouping grades with similar mortality risks, we obtained a five-grade hierarchical indicator ranging from robustness to severe stage of the continuum. Each state presented a gradually increasing risk of dying compared to the robust group (from Hazard Ratio (HR) = 2.20 [1.49–3.25] to 15.10 [9.99–22.82]).

Conclusions
We confirmed that combining pre-frailty, frailty, IADL- and ADL-disability into a single indicator may improve our understanding of the aging process. Pre-frailty identified as the ‘entry door’ into the process may represent a key stage that could offer new opportunities for early, targeted, individualized and tailored interventions and care in clinical geriatrics.
Implications of obesity for drug administration and absorption from subcutaneous and intramuscular injections: A primer
Authors: Erstad Brian L , Barletta Jeffrey F 
Published: February 2022

Abstract

Purpose
To discuss the potential implications of obesity for drug administration and absorption from subcutaneous (SC) and intramuscular (IM) injection sites.

Summary
The SC and IM routes are useful for the parenteral administration of medications to optimize pharmacokinetic properties such as time to onset and duration of effect, for cost considerations, or for ease of administration, such as when intravenous access is unavailable. The choice of SC or IM injection depends on the specific medication, with SC administration preferred for products such as insulin where a slower and more sustained response is desirable, while IM administration is usually preferred for products such as vaccines where more rapid absorption leads to a more rapid antibody response. Obesity has the potential to influence the rate and extent of absorption, as well as adverse effects, of medications administered by the SC or IM route through changes in SC tissue composition and depth or by inadvertent administration of IM medications into SC tissue because of improper needle length. Potential adverse effects associated with IM or SC injections in addition to pain, bruising, and hematoma formation include sciatic nerve injury, particularly with IM injection in the upper outer quadrant of the buttock; bone contusion or rarely osteonecrosis if the IM injection is excessively deep; and granulomas, fat necrosis, and calcification with SC injection.

Conclusion
Issues related to medication absorption in obese patients are likely to become more prominent in the future with increasing approvals of a wide range of biotherapeutic agents administered by SC injection. Studies should be directed toward these and other agents to assist with dosing decisions in this challenging population.