bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neural network architecture choice for modelling various configurations power system
Authors: Kavalerov B , Kilin G , Suslov A 
Published: April 2021

Abstract
Gas turbine power plants based on converted aircraft engines have been successfully produced in Perm city since 1991. Their power range is steadily expanding. Such gas turbine electro power stations have significant advantages. However, the need to make full use of these advantages requires power station control processes significant intellectualization. Intellectualization will provide an opportunity to improve the electricity quality, increase the power supply reliability and improve environmental friendliness. To achieve these goals, it is necessary to study the behavior of gas turbine power electro station in different operation modes and in various configurations power system. Such research can only be carried out on the basis of mathematical models. Moreover, these models should be high-speed, since the research of control algorithms requires a large number of various experiments in a limited time. One of the promising ways to obtain such mathematical models is to use the artificial neural networks apparatus. To construct a gas turbine power electro station mathematical model, it is necessary to choose such a neural network architecture that will allow obtaining a model for an acceptable period of time and will allow modeling the processes with the required accuracy. Therefore, the problem of choosing the neural network architecture is an urgent research priority. On the basis of the performed studies, the architecture of a neural network for modeling various configurations power system is proposed and substantiated.
Simulation of three-phase induction motor different bearing faults in Matlab Simulink environment
Authors: Salnikov S , Solodkiy E , Vishnyakov D 
Published: April 2021

Abstract
The article describes the simulation of bearing failures in a three-phase induction motor in the Matlab Simulink environment. According to statistics most of induction motor faults happens due to bearings destruction or stator winding insulation degradation. Vibration analysis is often used to diagnose the bearings condition. This paper considered the model designing principles of different types of bearing faults of induction motor.
Common approaches in vector control design of induction motor and permanent-magnet syncronous motor
Authors: Solodkiy E , Salnikov S , Vishnyakov D 
Published: April 2021

Abstract
The article describes a way to generalize current control loop structure for AC drives, by implementing general PI gains calculation block. Article contains block diagram of generalized current control loop for smooth-air-gap and salient-pole machines. Electromagnetic torque estimator is represented, whose design based on stator voltage and current measurements. Results of simulation modeling of electromagnetic torque estimator in pair with field-oriented control are represented.
Regional differentiation of energy consumption in urban households
Authors: Mokhov V , Eltsova M , Bauer M 
Published: April 2021

Abstract
The paper considers a very important problem for modern world - the energy consumption and energy saving. Nowadays households consume more than a quarter of global energy consumption (29%), which means that this sector has great savings potential. However, this potential for savings can only benefit upon development of proper structural policy measures and laws and implementation of appropriate energy-saving measures. This requires information on the future trends of energy demand and on the factors influencing this demand and the actual energy consumption. The main challenge for researchers presents the fact that energy consumption in the regional aspect is extremely uneven, structurally heterogeneous, which assumes the different measures for the energy saving in each region of the country. Besides, we were unable to find publications describe the contribution of various factors to the dynamics of the energy consumption of the regional economy at the municipal level. Hence, the paper analyzes stream-lined trends in the energy consumption in households of Germany which is one of the world leaders in these issues. So the paper highlights some factors as well as some trends affecting the energy consumption in households in the Perm region.
Similarity Detection of Natural-Language Questions and Answers using the VANiLLa dataset
Authors: Both A , Gashkov A , Eltsova M 
Published: April 2021

Abstract
Question Answering refers to the task of providing a matching answer for a given user’s natural-language question. We assume here that the received response from a Question Answering system is also given as a natural-language output. From this scenario the task is raised to validate if the received natural-language answer is valid w.r.t. the given question. In this paper, we will present our approach to compute the similarity of a question to the corresponding natural-language answer while using the features of the surface form of the question and the answer. Our metrics is the distinction between a matching answer and inappropriate answers to a given question. Hence, our research agenda is dedicated to improving the answer quality of Question Answering systems by using the natural-language representation of its input and output.
Application of Enzymes for Coconut Oil Extraction
Authors: Eshtiaghi M N , Nakthong N 
Published: April 2021

Abstract
Coconut oil is edible oil extracted from endosperm of coconut (Cocos Nucifera) using different methods. In this report the coconut oil extraction from coconut meat rasp using pineapple enzymes were studied and compared with commercial enzymatic oil extraction. Pineapple enzymes were extracted from fresh pineapple fruit. The effectiveness of pineapple enzyme extract on coconut oil extraction from coconut meat rasp was studied at different enzyme concentrations of 0.5 to 2% (W/W) and pH of 4.5 to 7.5 with incubation times of 2 to 8 hr at 40 to 70 °C respectively. The commercial technical enzymes used in this study were from different companies (Valley enzyme®, Novozyme® and AB-enzyme®). Valley enzyme® at 1% (w/w) enzyme concentration and 1:1 enzyme solution to coconut rasp ratio found to be the most effective commercial enzyme in comparison with Novozyme® and AB-enzyme®. The optimum conditions for coconut oil extraction from coconut meat rasp using pineapple enzyme were at 1% (W/W) enzyme concentration, pH 6.5, 60 °C and 6 hr, while the optimum conditions for Valley enzyme were at pH 5.5, 60 °C and 6 hr. Oil yield obtained from Valley enzyme® and pineapple enzyme extract under optimum conditions were 21.89% and 20.50%, respectively. Therefore, the pineapple enzyme extract is a promising natural alternative to commercial technical enzymes for coconut oil extraction.
Chemical Composition and Calorific Power of tree species in the Peruvian Andes
Authors: Belito E. E. , Alvarez-Montalván E. C. , Alvarez-Orellana C. J. , Laredo R. I. , Manrique-León S. , Julian-Laime E. 
Published: April 2021

Abstract
Many forest species of the Peruvian Andes are considered exceptional for having innumerable powers, such is the case of the calorific power product of the chemical composition of the species. This study was carried out in the Department of Huancavelica, Izcuchaca District, the analysis of samples was carried out at the National University of Central Peru and the National University of Agraria la Molina, where ASTM Standards were used to obtain data. The species that presented the highest calorific value was Caesalpinia spinosa with 4658.25 kcal / kg, since within its chemical composition it presented a greater amount of extractables and lignin, while the Vachellia macracantha and Tecoma stans species obtained 4422.05 and 4077.1 kcal / kg respectively. However, the three species studied prove to have an excellent calorific value due they are above 4000 kcal / kg.
Element specification in small lakes of the Kola Peninsula: geochemical and technogenic factors
Authors: Dinu M I 
Published: April 2021

Abstract
This study focuses on metal speciation research in Arctic lakes with technogenic pollution and other areas where natural processes prevail (background lakes and lakes with marine influence). Element speciation in 75 lakes in the Kola Peninsula was investigated in 2014 and 2018 taking into account the influence of different geochemical factors. The geochemical features of lake water in the investigated regions are documented and discussed. Membrane filtration was used with the following features: mechanical suspension and oxidized contaminants (>8 μm, 1.2 μm) for lakes near smelters and those subject to marine effects; light suspension colloids (0.45–0.1 μm) for the natural waters of background lakes; low molecular weight complexes, inorganic ions, bacteria, and viruses (less than 0.1 μm) for identification of labile and non-labile components. It has been proven that the bioavailable speciation (unbound with organic components) is determined by the physicochemical properties of organic matter, such as zeta potential, molecular weight, and colloid stability. In conventional background lakes, Fe and Al complexes with humic substances dominate, and the most associative elements of the lanthanide/actinide group repeat the tendency of Fe. In lakes with a clear marine influence, the complexation potential of organic substances is reduced due to Na ions, which deactivate humic functional groups. Multivariate statistical methods showed significant differences between the selected gradations of lake waters and the genetic similarities and differences in the behavior of element speciation.
Power systems’ performance under high renewables’ penetration rates: a natural experiment due to the COVID-19 demand shock
Authors: Colelli Francesco Pietro , Witkop Daan , De Cian Enrica , Tavoni Massimo 
Published: April 2021

Abstract
COVID-19 lockdowns make it possible to investigate the extent to which an unprecedented increase in renewables’ penetration may have brought unexpected limitations and vulnerabilities of current power systems to the surface. We empirically investigate how power systems in five European countries have dealt with this unexpected shock, drastically changing electricity load, the scheduling of dispatchable generation technologies, electricity day-ahead wholesale prices, and balancing costs. We find that low-cost dispatchable generation from hydro and nuclear sources has fulfilled most of the net-load even during peak hours, replacing more costly fossil-based generation. In Germany, the UK, and Spain coal power plants stood idle, while gas-fired generation has responded in heterogeneous ways across power systems. Falling operational costs of generators producing at the margin and lower demand, both induced by COVID-19 lockdowns, have significantly decreased wholesale prices. Balancing and other ancillary services’ markets have provided the flexibility required to respond to the exceptional market conditions faced by the grid. Balancing costs for flexibility services have increased heterogeneously across countries, while ancillary markets’ costs, measured only in the case of Italy, have increased substantially. Results provide valuable evidence on current systems’ dynamics during high renewables’ shares and increased demand volatility. New insights into the market changes countries will be facing in the transition towards a clean, secure, and affordable power system are offered.
The connection between forest degradation and urban energy demand in sub-Saharan Africa: a characterization based on high-resolution remote sensing data
Authors: Sedano F , Lisboa S N , Sahajpal R , Duncanson L , Ribeiro N , Sitoe A , Hurtt G , Tucker C J 
Published: April 2021

Abstract
Charcoal is a key energy source for urban households in sub-Saharan Africa and charcoal production is the main cause of forest degradation across the region. We used multitemporal high-resolution remote sensing optical imagery to quantify the extent and intensity of forest degradation associated with charcoal production and its impact on forest carbon stocks for the main supplying area of an African capital. This analysis documents the advance of forest degradation and quantifies its aboveground biomass removals over a seven-year period, registering that, between 2013 and 2016, the average annual area under charcoal production was 103 km2 and the annual aboveground biomass removals reached 1081 000 (SD = 2461) Mg. Kiln densities in the study area rose to 2 kilns-ha, with an average of 90.7 Mg ha−1 of extracted aboveground biomass. Charcoal production was responsible for the degradation of 55.5% of the mopane woodlands in the study area between 2013 and 2019. We estimated post-disturbance recovery times using an ecosystem model calibrated for the study area. The simulations showed that recovery times could require up to 150 years for current aboveground biomass extraction rates. The results of the remote sensing analysis and the simulations of the ecosystem model corroborate the unsustainability of the present patterns of charcoal production. The detailed characterization of the spatial and temporal patterns of charcoal production was combined with household survey information to quantify the impact of the urban energy demand of the Maputo urban area on forest carbon stocks. The analysis shows that Maputo charcoal demand was responsible for the annual degradation of up to 175.3 km2 and that the contribution of the study area to this demand fluctuated between 75% and 33% over the study period. The extent, advance pace and distance from urban centers documented in this study support the idea that forest degradation from charcoal production cannot merely be considered a peri-urban process. The intensity of the aboveground biomass (AGB) removals and its contribution to forest carbon stocks changes is significant at the national and regional levels.
Climatic controls on the hydrologic effects of urban low impact development practices
Authors: Voter Carolyn B , Loheide Steven P 
Published: April 2021

Abstract
To increase the adoption and reliability of low impact development (LID) practices for stormwater runoff management and other co-benefits, we must improve our understanding of how climate (i.e. patterns in incoming water and energy) affects LID hydrologic behavior and effectiveness. While others have explored the effects of precipitation patterns on LID performance, the role of energy availability and well-known ecological frameworks based on the aridity index (ratio of potential evapotranspiration (ET) to precipitation, PET:P) such as Budyko theory are almost entirely absent from the LID scientific literature. Furthermore, it has not been tested whether these natural system frameworks can predict the fate of water retained in the urban environment when human interventions decrease runoff. To systematically explore how climate affects LID hydrologic behavior, we forced a process-based hydrologic model of a baseline single-family parcel and a parcel with infiltration-based LID practices with meteorological records from 51 U.S. cities. Contrary to engineering design practice which assumes precipitation intensity is the primary driver of LID effectiveness (e.g. through use of design storms), statistical analysis of our model results shows that the effects of LID practices on long-term surface runoff, deep drainage, and ET are controlled by the relative balance and timing of water and energy availability (PET:P, 30 d correlation of PET and P) and measures of precipitation intermittency. These results offer a new way of predicting LID performance across climates and evaluating the effectiveness of infiltration-based, rather than retention-based, strategies to achieve regional hydrologic goals under current and future climate conditions.
Climate-induced stressors to peace: a review of recent literature
Authors: Sharifi Ayyoob , Simangan Dahlia , Lee Chui Ying , Reyes Sheryl Rose , Katramiz Tarek , Josol Jairus Carmela , Dos Muchangos Leticia , Virji Hassan , Kaneko Shinji , Tandog Thea Kersti , Tandog Leorence , Islam Moinul 
Published: April 2021

Abstract
Climate change is increasingly recognized as a threat to global peace and security. This paper intends to provide a better understanding of the nature of interactions between climate change and events that undermine peace through a systematic review of recent literature. It highlights major methodological approaches adopted in the literature, elaborates on the geographic focus of the research at the nexus of climate change and peace, and provides further information on how various climatic stressors, such as extreme temperature, floods, sea-level rise, storms, and water stress may be linked to different events that undermine peace (e.g. civil conflict, crime, intercommunal violence, interstate conflict, political conflict, and social conflict) through direct and indirect pathways. Results confirm previous findings that statistical techniques and qualitative case studies are dominant methods in climate-conflict research but show that there has been an increase in the geographic information system based risk analyses and qualitative comparative analyses in the recent years. In line with previous reviews, results show that the literature is mainly focused on certain regions of the world and several major regions that have experienced numerous conflicts over the past few years and/or are vulnerable to adverse climatic events are understudied. However, a new finding is that, in the past few years, there has been an increasing focus on Asia, which contrasts with previous reviews that show an African focus in the literature. Also, there is an unbalanced attention to different climatic stressors and peace-related events. Interactions between water stress/extreme temperature and civil and interstate conflicts have received more attention. A major finding is that, only under certain conditions climatic stressors may act as driving forces or aggravating factors. In fact, there is a strong consensus that climate change is less likely to undermine peace in isolation from a wide range of contextual socio-economic and institutional factors such as political instability, poor governance, poverty, homogeneous livelihood structures, and ethnic fractionalization. However, such contextual factors can contribute to undermining peace via either direct or indirect pathways. The former may occur through direct psychological/physiological effects of climatic impacts or via competition over scarce resources. In contrast, in indirect pathways climate change may lead to conflict through diminishing livelihood capacities and/or inducing migration. In addition to synthesizing literature on contextual factors and direct/indirect pathways, the review identifies gaps that need further research.
Airy gas model: from three to reduced dimensions
Authors: Bencheikh K , Putaja A , Räsänen E 
Published: April 2021

Abstract
By using the propagator of linear potential as a main tool, we extend the Airy gas (AG) model, originally developed for the three-dimensional (d = 3) edge electron gas, to systems in reduced dimensions (d = 2, 1). First, we derive explicit expressions for the edge particle density and the corresponding kinetic energy density (KED) of the AG model in all dimensions. The densities are shown to obey the local virial theorem. We obtain a functional relationship between the positive KED and the particle density and its gradients and analyze the results inside the bulk as a limit of the local-density approximation. We show that in this limit the KED functional reduces to that of the Thomas–Fermi model in d dimensions.
Identification of the optimal parameters of the torsional vibration damper of the internal combustion engine crankshaft for normal power settings
Authors: Khaliullin Farit , Pikmullin Gennady , Aladashvili Joseph , Vakhrameev Dmitry , Potapov Evgeny 
Published: April 2021

Abstract
This article is devoted to determining the parameters of torsional vibration dampers of the internal combustion engine crankshaft in the entire high-speed mode of its operation. Currently, these parameters are set only for one main harmonic of the distributing moment. At the same time, it is assumed that the remaining harmonics give a slight increase in the amplitude of torsional vibrations. Changing the rotation rate of the crankshaft in the entire range of the operating mode leads to the appearance of other resonant modes, although not as significant as the main resonant mode. Therefore, for more stable quenching of torsional vibrations, a quenching device with variable characteristics is required. The proposed method for determining the parameters of the torsional vibration damper under changing speed and load modes of the internal combustion engine, which ensure efficient use, can be useful in the design of new highly accelerated internal combustion engines.
Seismic hazard analyses for North Java Offshore Indonesia using ISO 19901-2:2004
Authors: Hendriyawan H , Aditramulyadi D D , Syahbana A J 
Published: April 2021

Abstract
Most offshore platforms in Indonesia use API RP 2A WSD as a guideline for designing earthquake-resistance offshore structures. However, this guideline does not explicitly state the return periods and the procedures for developing the designed response spectrum for used in seismic design. The procedures are described in more detail in ISO 19901-2 which stated explicitly requirement design parameter of 1.0s oscillator period and for a 0.2s oscillator period for a 1000-years return period of the earthquake. The paper presented a development of seismic hazard maps for 1.000 years return period for North Java Offshore Indonesia. The seismic hazard maps were modeled by the USGS PSHA program based on probabilistic concepts. The seismic sources used in the analyses were based on the latest researches published by National Center for Earthquake Studies (PuSGeN) in 2017. The study reveals that, generally, North Java Offshore Indonesia can be categorized as seismic zone 1 and 2 and East Madura as seismic zone 3 in accordance to ISO 19901-2.
Study of runway crosswind and tailwind potential for airport sustainability: A study of Soekarno Hatta airport, Cengkareng, Indonesia
Authors: Sardjono W , Zulkarnain  , Kusnoputranto H , Soesilo TEB , Utama DN , Sudirwan J 
Published: April 2021

Abstract
Airport runway designs must consider wind climatology to reduce the potential for crosswind and tailwind events that can cause accidents and aircraft delays. The large potential of crosswind and tailwind on a runway at the airport is very detrimental to aircraft passengers and airlines. Therefore, it is necessary to know the potential of crosswind and tailwind on the runway of Soekarno Hatta Airport and find the right parameters for the approximate direction and speed of the wind on the airport runway. Analysis was carried out using the direction and wind speed data from the Soekarno Hatta meteorological station in 2007-2017 to determine the potential for crosswind and tailwind on the runway of Soekarno Hatta airport and run a Weather Research and Forecasting (WRF) weather model to determine the parameterization of the right weather model for wind forecast at Soekarno Hatta airport. The highest maximum crosswind component in the 2007-2017 period occurred in August 30.53 knots, while the highest maximum tailwind of 25 knots occurred in January for a 250-degree runway and 24 knots occurred in August for a 070-degree runway. The potential for crosswind and tailwind is different every month. The scheme produces forecasts of wind direction and speed with a strong level of correlation with observations of wind direction and speed from the Soekarno Hatta meteorological station, the correlation value is 0.61. The most significant social impact of plane delays is time loss for passengers. While the economic impact on one of the crosswind events at Soekarno Hatta airport was an economic loss for one airline of US $ 43,392.