bluuebunny/crossref_metadata_2025_split huggingface dataset:
The “Bi-drifting” Subpulses of PSR J0815+0939 Observed with the Five-hundred-meter Aperture Spherical Radio Telescope
Authors: Shang Lun-Hua , Bai Jun-Tao , Dang Shi-Jun , Zhi Qi-Jun 
Published: December 2021

Abstract
We report the “Bi-drifting” subpulses observed in PSR J0815+0939 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The observation at band from 1050 to 1450 MHz is evenly divided into two bands, i.e., the bands at center frequencies of 1150 and 1350 MHz. The mean pulse profiles and the “Bi-drifting” subpulses at these two bands are investigated. It is found that the pulse profiles at these two frequencies show four emission components, and the peak separations between four emission components decrease with the increase of frequency. In addition, the ratio of peak intensity of each component to the intensity of component IV at 1150 MHz is larger than that at 1350 MHz. We carry out an analysis of the longitude-resolved fluctuation spectrum and two-dimensional fluctuation spectrum for each emission component, and find that the P3 of components I, II and III is about 10.56, 10.57 and 10.59 s at 1150 and 1350 MHz. However, the reliable measurements of P3 of component IV and P2 for these four components were not obtained due to the low signal-to-noise ratio of observation data. The pulse energy distributions at frequencies 1150 and 1350 MHz are presented, and it is found that no nulling phenomenon has been found in this pulsar. With our observation from the FAST, the “Bi-drifting” subpulse phenomenon of PSR J0815+0939 is expanded from 400 to 1350 MHz, which is helpful for the relevant researchers to test and constrain the pulsar emission model, especially the model of “Bi-drifting” subpulse.
Calibrating Photometric Redshift Measurements with the Multi-channel Imager (MCI) of the China Space Station Telescope (CSST)
Authors: Cao Ye , Gong Yan , Zheng Zhen-Ya , Xu Chun 
Published: December 2021

Abstract
The China Space Station Telescope (CSST) photometric survey aims to perform a high spatial resolution (∼0.″15) photometric imaging for the targets that cover a large sky area (∼17,500 deg2) and wide wavelength range (from NUV to NIR). It expects to explore the properties of dark matter, dark energy, and other important cosmological and astronomical areas. In this work, we evaluate whether the filter design of the Multi-channel Imager (MCI), one of the five instruments of the CSST, can provide accurate photometric redshift (photoz) measurements with its nine medium-band filters to meet the relevant scientific objectives. We generate the mock data based on the COSMOS photometric redshift catalog with astrophysical and instrumental effects. The application of upper limit information of low signal-to-noise ratio data is adopted in the estimation of photoz. We investigate the dependency of photoz accuracy on the filter parameters, such as band position and width. We find that the current MCI filter design can achieve good photoz measurements with accuracy σ

z
≃ 0.017 and outlier fraction f
c ≃ 2.2%. It can effectively improve the photoz measurements of the main CSST survey using the Survey Camera to an accuracy σ

z
≃ 0.015 and outlier fraction f
c ≃ 1.5%. This indicates that the original MCI filters are proper for the photoz calibration.
Neural tracking to go: auditory attention decoding and saliency detection with mobile EEG
Authors: Straetmans L , Holtze B , Debener S , Jaeger M , Mirkovic B 
Published: December 2021

Abstract

Objective. Neuro-steered assistive technologies have been suggested to offer a major advancement in future devices like neuro-steered hearing aids. Auditory attention decoding (AAD) methods would in that case allow for identification of an attended speaker within complex auditory environments, exclusively from neural data. Decoding the attended speaker using neural information has so far only been done in controlled laboratory settings. Yet, it is known that ever-present factors like distraction and movement are reflected in the neural signal parameters related to attention. Approach. Thus, in the current study we applied a two-competing speaker paradigm to investigate performance of a commonly applied electroencephalography-based AAD model outside of the laboratory during leisure walking and distraction. Unique environmental sounds were added to the auditory scene and served as distractor events. Main results. The current study shows, for the first time, that the attended speaker can be accurately decoded during natural movement. At a temporal resolution of as short as 5 s and without artifact attenuation, decoding was found to be significantly above chance level. Further, as hypothesized, we found a decrease in attention to the to-be-attended and the to-be-ignored speech stream after the occurrence of a salient event. Additionally, we demonstrate that it is possible to predict neural correlates of distraction with a computational model of auditory saliency based on acoustic features. Significance. Taken together, our study shows that auditory attention tracking outside of the laboratory in ecologically valid conditions is feasible and a step towards the development of future neural-steered hearing aids.
Implementation of planar 3D hydraulic fracture model in rock with layered compressive stress
Authors: Lapin V 
Published: December 2021

Abstract
Plane 3D model of hydraulic fracture propagation is implemented. Fluid flow inside the fracture, leak-of, rock deformation and breaking are taken into account. Asymptotic solution for tip of semi-infinite plane fracture is used to set boundary conditions for fluid flow problem and to calculate fracture front propagation velocity. Elastic and fluid flow equations are united in one system of nonlinear equations and solved simultaneously by Newton method with analytically calculated Jacoby matrix. The implemented model may be used as a start point for testing various methods of solution of “hydrodynamic-elasticity” problem and improving their convergence speed. Also model can be used for developed hydraulic fracture simulation.
Application of various ice accretion simulation approaches in the LOGOS software package
Authors: Galanov N G , Sarazov A V , Zhuchkov R N , Kozelkov A S 
Published: December 2021

Abstract
This paper presents results of the ice accretion simulations by the techniques implemented in the LOGOS-Aero module of the LOGOS software package. The results of the Eulerian and the Lagrangian ice accretion simulations are reported for NACA verification problems, which are used to test the software package Lewice. The approaches implemented in the LOGOS-Aero enable simulations of the aircraft icing conditions and the predictions of the shapes and locations of ice deposits on computational models.
Analysis of aerosol pollution processes in the vicinity of the Irkutsk aluminum plant
Authors: Raputa V F , Grebenshchikova V I , Lezhenin A A , Yaroslavtseva T V , Amikishieva R A 
Published: December 2021

AbstractThe issues of assessing the pollution fields in the vicinity of industrial enterprises are discussed according to the monitoring studies of the snow cover. The formulations of problems of low-parameter reconstruction of concentration fields are considered on the basis of model descriptions of the processes of transport of impurities in the surface layer of the atmosphere. With regard to the Irkutsk aluminum plant, the results of studies of the pollution of its surroundings with aluminum are presented. Using the data of route observations, a numerical reconstruction of the fluoride content in the snow cover was carried out. The quality control of the results obtained is carried out by comparing the measured and calculated concentrations of impurities at the control points of observation.
Sensitivity of functionals in variational data assimilation for a sea thermodynamics model
Authors: Shutyaev V P , Parmuzin E I , Yu Gejadze I 
Published: December 2021

Abstract
The sensitivity of functionals of the optimal solution to a variational data assimilation problem for the sea thermodynamics model is studied. The variational data assimilation problem is formulated as an optimal control problem to find the initial state and the boundary condition. The sensitivity of the response functions as functionals of the optimal solution with respect to the observation data is determined by the gradient of the response function and reduces to the solution of a non-standard problem being a coupled system of direct and adjoint equations with mutually dependent initial and boundary values. The algorithm to compute the gradient of the response function is presented, based on the Hessian of the original cost functional. The sensitivity analysis of the response function with respect to errors of observation data is carried out. Numerical examples are presented for the Black Sea thermodynamics model.
Studying the interaction of a reservoir with an ideal compressible fluid with an elastic half-space
Authors: Telyatnikov I S , Pavlova A V , Rubtsov S E 
Published: December 2021

Abstract
We solve in a flat formulation the problem of harmonic oscillations for a basin with an ideal compressible fluid on an elastic half-space exposed to a localized surface vibration load. The problem reduces to an integral equation (IE) of the first kind for the amplitude of the contact hydrodynamic pressure with a kernel that depends on the difference and the sum of arguments. The IE was solved by the factorization method. A semi-analytical method is presented for determining the main parameters of the contact interaction in hydroelastic systems «liquid-soil» taking into account the effect of natural and man-made vibration loads on them. This makes it possible to identify the conditions for the occurrence of dynamic modes that are dangerous for the construction integrity and to estimate their frequencies range depending on defining characteristics of the system.
Emergence of optimal disturbances in a stratified turbulent shear flow under the stochastic forcing
Authors: Zasko G V , Perezhogin P A , Glazunov A V , Mortikov E V , Nechepurenko Y M 
Published: December 2021

Abstract
Large-scale inclined organized structures in stably stratified turbulent shear flows were revealed in the numerical simulation and indirectly confirmed by the field measurements in the stable atmospheric boundary layer. Spatial scales and forms of these structures coincide with those of the optimal disturbances of a simplified linear model. In this paper, we clarify the relation between the organized structures and the optimal disturbances, analyzing a time series of turbulent fields obtained by the RANS model with eddy viscosity/diffusivity and stochastic forcing generating the small-scale turbulence.
Formalization of target invariants and designing an adaptive control system for the model of anaerobic biological wastewater treatment
Authors: Fomenkova A A , Klucharev A A , Kolesnikova S I 
Published: December 2021

Abstract
A model of a two-step anaerobic fermentation in a bioreactor-mixer, whose mathematical description is a system of nonlinear mathematical equations, is discussed. The purpose is to design an algorithm of an energy-saving control relying on the principles of nonlinear adaptation on target manifolds with an attractive property, which are referred to as invariants or invariable laws of the target system behavior for the object under study. A necessary preliminary step is the formalization of possible target invariants in the form of prescribed (desired) laws of the controlled object behavior. An example is given of designing a vector regulator with a compensation of random disturbances over the control channel in a system of anaerobic biological waste water treatment.
Determination of the bottom scattering coefficient discontinuity lines in the multibeam ocean sounding
Authors: Kovalenko E O , Prokhorov I V 
Published: December 2021

Abstract
In this paper the problems of constructing sonar images of the seabed according to measurements of the multibeam side scan sonar are considered. The inverse problem for the non-stationary equation of radiation transfer with the diffuse reflection conditions at the boundary which consists in finding the discontinuity lines of the bottom scattering coefficient is investigated. A numerical algorithm for solving the inverse problem is developed, and an analysis of the quality of reconstructing the boundaries of inhomogeneities of the seabed is carried out, depending on the number of views and the width of a radiation pattern and the sounding range.
An inverse problem for a system of nonlinear parabolic equations
Authors: Tabarintseva E 
Published: December 2021

Abstract
The inverse problem for a system of nonlinear parabolic equations is considered in the present paper. Namely, it is required to restore the initial condition by a given time-average value of the solution to the system of the nonlinear parabolic equations. An exact in the order error estimate of the optimal method for solving the inverse problem through the error estimate for the corresponding linear problem is obtained. A stable approximate solution to the unstable nonlinear problem under study is constructed by means of the projection regularization method which consists of using the representation of the approximate solution as a partial sum of the Fourier series. An exact in the order estimate for the error of the projection regularization method is obtained on one of the standard correctness classes. As a consequence, it is proved the optimality of the projection regularization method. As an example of a nonlinear system of parabolic equations, which has important practical applications, a spatially distributed model of blood coagulation is considered.
Earthquake record processing algorithms to form a strong motion database
Authors: Mironov V A , Peretokin S A , Simonov K V 
Published: December 2021

Abstract
This study is devoted to the development of algorithms and software for earthquake record processing. The algorithms are based on the methodology used by the Pacific Earthquake Engineering Research Center for the implementation of the scientific project NGA-West2. The purpose of processing is to determine reliable values of ground acceleration and other parameters of earthquakes from the available records of velocity time series. To analyze the operation of the algorithms, earthquake records (simultaneously recorded time series of acceleration and velocity) taken from the European Rapid Raw Strong-Motion database were used. The developed algorithms and the implemented software will allow in the future to form a database of strong motions for building regional attenuation models on the territory of the Russian Federation.
A divide-and-conquer algorithm for seismic data approximation by the Laguerre series
Authors: Terekhov Andrew V 
Published: December 2021

Abstract
An algorithm of the Laguerre transform for approximating functions on large intervals is proposed. The idea of the considered approach is that the calculation of improper integrals of rapidly oscillating functions is replaced by a solution of an initial boundary value problem for the one-dimensional transport equation. It allows one to successfully avoid the problems associated with the stable implementation of the Laguerre transform. A divide-and-conquer algorithm based on shift operations made it possible to significantly reduce the computational cost of the proposed method. Numerical experiments have shown that the methods are economical in the number of operations, stable, and have satisfactory accuracy for seismic data approximation.
Study on The Characteristics of NaCl Treated Kenaf Fiber Epoxy Composite Board
Authors: Setyayunita T , Widyorini R , Marsoem S N , Irawati D 
Published: December 2021

AbstractThe treatment of kenaf fiber surfaces with chemicals has proven to be an effective method to improve composite properties. Meanwhile, natrium chloride (NaCl) is one of the chemicals that has great potential to be used for modifying natural fibers. Therefore, this study aims to investigate the characteristics of a composite board made from NaCl-treated kenaf fiber and epoxy. The method used was a completely randomized design with two factors, namely the level of NaCl in the treatment solution including 1, 3, and 5%wt, as well as the epoxy content of 10, 20, and 30%wt based on the dry weight fiber. The NaCl treatment was carried out by soaking the fibers in the solution for 1 hour at room temperature, rinsed using water until the pH of the water reached 7, and then dried in an oven at 80ᵒC for 6 hours. Furthermore, the Kenaf fiber and epoxy were mixed manually, while the boards were manufactured using a heat pressing system at 120ᵒC, with a pressure of 3.5 MPa for 10 minutes, and a thickness of 10 mm. The physical and mechanical properties were then evaluated based on JIS A5908. The results showed that the composite board properties were optimum at NaCl 5%, 20% of epoxy, modulus of elasticity and rupture of 2.02 GPa, and 18.63 MPa respectively, internal bonding 1.94 MPa, thickness swelling 2.89 %, and water absorption of 10.49%. The results showed that the physical and mechanical properties of the composite board increased with a high NaCl concentration.
The Efficacy of Pine Wood Pellets reinforced with Active Hexaflumuron Against the Subterranian Termite Coptotermes curvignathus Holmgren
Authors: Arinana  , Silalahi A R E , Hendra D , Nandika D 
Published: December 2021

AbstractBait formulation using hexaflumuron is the most used baiting techniques because it is relatively friendly to the environment. One of the potential wood species for bait formulation for termites is pine wood. The resin in pine wood can reduce termites preference. Therefore, the resin contained in pine wood needs to be reduced so that the level of termites preference for pine wood can be increased. This study aims to determine the efficacy of the bait formulation in the form of pellets from pine wood (Pinus merkusiiJungh er de Vries) which was pre-treated with presto (0.4 bar, 100 °C) for one, two, three, four, and five hours with active hexaflumuron (0.25%) against subterranean termitesCoptotermes curvignathus.Pine wood chips were treated with presto for one hour, two hours, three hours, four hours, and five hours. The treated pine wood chips then made into sawdust by 40-60 mesh. Pine sawdust then added with hexaflumuron (0.25%) and formed into pellets without adding any adhesive material and then fed to the subterranean termitesC. curvignathus(JIS K 1571: 2010). Solid pine wood used as a control sample. The result showed that palatability of formulation pellet bait with active hexaflumuron (14.33%) was higher than solid pine wood (6.58%). The formulation of pellet bait with 0.25% active hexaflumuron with presto pre-treatment was able to eliminateC. curvignathustermites.
Specific gravity, Extractive Content, and Natural Durability of Balsa (Ochroma pyramidale) Wood at 3 and 4 years old
Authors: Listyanto T , Poedyastanto E P F , Abqoriah S M , Lukmandaru G 
Published: December 2021

AbstractThe aim was to investigate the specific gravity, extractive content, and natural durability of balsa (Ochroma pyramidale) wood. A total of six trees of balsa at 3 and 4 years old were harvested and cut into the sample of specific gravity, extractive content, and natural durability test. Natural durability was tested according to SNI 01-7207-2006 against dry wood termites (Cryptotermes cynocephalusLight.). Specific gravity, extractive content, mass losses, and termite mortality were measured. Variance analysis was used to find the differences. The results showed that age influenced significantly on specific gravity and mass losses, while axial direction/position influenced significantly on extractive content and mass losses. Variance analysis also showed that radial direction influenced significantly on specific gravity and extractive content. The specific gravity of three years balsa wood is 0.14, which is lower than that of four years old three, which is 0,19. Extractive content in the bottom part (3.95%) is higher than that of in the middle (2.87%) and top (2.74%). Mortality in the bottom part (33.83%) is higher than that of in the middle (10.5%) and top part (5,8%) of the stem. In general, balsa wood is classified into durability class II-III.
Coconut (Cocos nucifera Linn.) Root Extraction and Application as A Fabric Dye with Different Particle Sizes and Extraction Methods
Authors: Pujiarti R , Putri O A 
Published: December 2021

Abstract
Coconut (Cocos nucifera Linn.) root can be used as an alternative to natural dyes because it contains color pigments in the form of flavonoids. Extraction of natural dyes is affected by several factors such as the type of solvent, extraction temperature, ratio of solvent and raw material, particle size, stirring, and extraction time. This study ware aims to determine combination factor of the particles size and extraction methods of coconut root dye on the characteristics and colour fastness of the fabric products. The coconut root powder in 60 and 40 mesh sizes were extracted by boiling distilled water and maceration with 70 and 95% ethanol, respectively. The coconut root dye was tested for the color characteristics and the dye solution was applied to the fabric and tested for the color fastness. The results showed that the particle size and extraction methods used had a significant effect on color intensity while pH value and color index were not significantly different. The highest color intensity was 2.044, the effect of temperature at 30 was 1.949, and the effect of temperature at 100°C was 1.920. The pH value of the coconut root dye solution is acidic with an average pH of 5.85 while the color names from the test results using NADIM 2021 produce three color categories, namely foxtrot, tobacco brown, and pale gold. Although it is not significantly affected by the combination of material size factors and the extraction methods of coconut root dye solution, the results of the color fastness test tend to meet the standards of SNI 8302-2016 regarding the quality requirements for the fastness of written batik. The average grey scale value for each test is 3-4 (Good enough), the staining scale value is 4-5 (Good), and the sunlight resistance test value is 4 (Good).
Total Phenolic Content, Antioxidant, and Sunscreen Activities of Daemonorops draco Resin Extracts from Extraction at Various Ethanol Concentrations and Resin-Solvent Ratio
Authors: Asidah N , Sari R K , Rafi Mohamad , Syafitri UD 
Published: December 2021

AbstractThis research aimed to determine the yield, total phenolic content (TPC), in vitro sunscreen (SPF), and antioxidant activities (AA) ofDamonorops dracoresin (DDR). The DDR was macerated with ethanol at various concentration (EC) namely 100% (E100), 90% (E90), 80% (E80), and 70% (E70) and the DDR:solvent ratio (D:S) were 1:5, 1:10, and 1:15. This research showed that the interaction between the EC and D:S affected AA, SPF, and TPC of DDR extract (DDRE), but it didn’t affect the DDRE yield. The DDR extraction with E70, E100, and D:S of 1:15 produced the highest DDRE yield. The extraction with E70 and three different D:S produced DDRE with the highest TPC. The highest AA of DDRE was obtained from extraction with E80 and D:S 1:10 (E80-10), E70-15, and E90-5 respectively. The highest SPF of DDRE was obtained from the extraction with E90-15, E70-15, E90-5, and E70-10, respectively. The extraction with E70 and D:S of 1:15 is the best extraction condition because it produces DDRE with a yield of 17.4±3.9%-20.71±1.6%; TPC of 263.93±5.25 mg GAE/g DDRS; AA with an IC value of 78.3±0.3 ppm, and sunscreen with an SPF value of 33.1±0.0.