bluuebunny/crossref_metadata_2025 huggingface dataset:
A multi-population state optimization algorithm for rail crack fault diagnosis
Authors: Liu Mengmeng , Gao Ruipeng , Zhao Jiao , Wang Yiran , Shao Wei
Published: December 2021

Rails usually operate in complex environments, which makes them prone to mechanical failures. In order to better diagnose crack faults, a multi-population state optimization algorithm (MPVHGA) is proposed in this paper, which is used to solve the problems of low efficiency, easy precocity, and easy convergence of local optimal solutions in traditional genetic algorithms. The fault signal detection results show that the MPVHGA has the advantages of fast convergence rate, high stability, no stagnation, and no limitation of the number of fixed iterations. The average iterations number of MPVHGA in 100 independent iterations is about one-fifth of the traditional single genetic algorithm (SGA for short) and about one-third of the population state optimization algorithm (VHGA for short), and the total convergence number of the MPVHGA converges to 55 and 10 more than the SGA and VHGA, respectively, and the accuracy of its fault diagnosis can reach 95.04%. On the basis of improving the performance of simple genetic algorithms, this paper provides a new detection method for rail crack fault diagnosis, which has important practical value in engineering.
Oxygen-plasma-assisted formaldehyde adsorption mechanism of SnO2 electrospun fibers
Authors: Du Haiying , Wu Yuxia , Zhang Zhaorui , He Wanmin , Wang Jing , Sun Yanhui , Cong Liying
Published: December 2021

Chemisorbed oxygen acts a crucial role in the redox reaction of semiconductor gas sensors, and which is of great significance for improving gas sensing performance. In this study, an oxygen-plasma-assisted technology is presented to enhance the chemisorbed oxygen for improving the formaldehyde sensing performance of SnO2 electropun fiber. An inductively coupled plasma device was used for oxygen plasma treatment of SnO2 electrospun fibers. The surface of SnO2 electrospun fibers was bombarded with high-energy oxygen plasma for facilitating the chemisorption of electronegative oxygen molecules on the SnO2 (110) surface to obtain an oxygen-rich structure. Oxygen-plasma-assisted SnO2 electrospun fibers exhibited excellent formaldehyde sensing performance. The formaldehyde adsorption mechanism of oxygen-rich SnO2 was investigated using density functional theory. After oxygen plasma modification, the adsorption energy and the charge transfer number of formaldehyde to SnO2 were increased significantly. And an unoccupied electronic state appeared in the SnO2 band structure, which could enhance the formaldehyde adsorption ability of SnO2. The gas sensing test revealed that plasma-treated SnO2 electrospun fibers exhibited excellent gas sensing properties to formaldehyde, low operating temperature, high response sensitivity, and considerable cross-selectivity. Thus, plasma modification is a simple and effective method to improve the gas sensing performance of sensors.
Effect of dielectric surface passivation on organic field-effect transistors: spectral analysis of the density of trap-states
Authors: Yadav Yogesh , Singh Samarendra Pratap
Published: December 2021

The semiconductor/dielectric interface is arguably the most important region in field-effect transistors. This article investigates the performance-enhancing effects of passivation of the dielectric surface by a self-assembled layer (SAM) of silanes on organic field-effect transistors. Apart from conventional figures of merit for the devices, the energetic distribution of the density of the in-gap trap-states (trap-DOS) and the contact resistance are evaluated using numerical methods. The investigation reveals that the surface passivation of the dielectric SiO2 has a dual effect on device operation. Firstly, it establishes quantitatively that the surface passivation leads to a significant reduction in the density of both shallow and deep traps in the organic semiconductor PBTTT-C14. This effect outweighs the impact of the SAM dipoles on the device turn-on. Secondly, the contact resistance gets lowered by a factor of more than 10 due to the improved top-surface morphology of the PBTTT-C14 thin film. The lower contact resistance in devices is corroborated by lower contact potential difference between PBTTT-C14 and gold, measured using scanning kelvin probe microscopy.
Single particle detection system for strong-field QED experiments
Authors: Salgado F C , Cavanagh N , Tamburini M , Storey D W , Beyer R , Bucksbaum P H , Chen Z , Di Piazza A , Gerstmayr E , Harsh  , Isele E , Junghans A R , Keitel C H , Kuschel S , Nielsen C F , Reis D A , Roedel C , Sarri G , Seidel A , Schneider C , Uggerhøj U I , Wulff J , Yakimenko V , Zepter C , Meuren S , Zepf M
Published: December 2021

Measuring signatures of strong-field quantum electrodynamics (SF-QED) processes in an intense laser field is an experimental challenge: it requires detectors to be highly sensitive to single electrons and positrons in the presence of the typically very strong x-ray and γ-photon background levels. In this paper, we describe a particle detector capable of diagnosing single leptons from SF-QED interactions and discuss the background level simulations for the upcoming Experiment-320 at FACET-II (SLAC National Accelerator Laboratory). The single particle detection system described here combines pixelated scintillation LYSO screens and a Cherenkov calorimeter. We detail the performance of the system using simulations and a calibration of the Cherenkov detector at the ELBE accelerator. Single 3 GeV leptons are expected to produce approximately 537 detectable photons in a single calorimeter channel. This signal is compared to Monte-Carlo simulations of the experiment. A signal-to-noise ratio of 18 in a single Cherenkov calorimeter detector is expected and a spectral resolution of 2% is achieved using the pixelated LYSO screens.
Handling EEG artifacts and searching individually optimal experimental parameter in real time: a system development and demonstration
Authors: Ouyang Guang , Dien Joseph , Lorenz Romy
Published: December 2021

Objective. Neuroadaptive paradigms that systematically assess event-related potential (ERP) features across many different experimental parameters have the potential to improve the generalizability of ERP findings and may help to accelerate ERP-based biomarker discovery by identifying the exact experimental conditions for which ERPs differ most for a certain clinical population. Obtaining robust and reliable ERPs online is a prerequisite for ERP-based neuroadaptive research. One of the key steps involved is to correctly isolate electroencephalography artifacts in real time because they contribute a large amount of variance that, if not removed, will greatly distort the ERP obtained. Another key factor of concern is the computational cost of the online artifact handling method. This work aims to develop and validate a cost-efficient system to support ERP-based neuroadaptive research. Approach. We developed a simple online artifact handling method, single trial PCA-based artifact removal (SPA), based on variance distribution dichotomies to distinguish between artifacts and neural activity. We then applied this method in an ERP-based neuroadaptive paradigm in which Bayesian optimization was used to search individually optimal inter-stimulus-interval (ISI) that generates ERP with the highest signal-to-noise ratio. Main results. SPA was compared to other offline and online algorithms. The results showed that SPA exhibited good performance in both computational efficiency and preservation of ERP pattern. Based on SPA, the Bayesian optimization procedure was able to quickly find individually optimal ISI. Significance. The current work presents a simple yet highly cost-efficient method that has been validated in its ability to extract ERP, preserve ERP effects, and better support ERP-based neuroadaptive paradigm.
I-mode pedestal relaxation events in the Alcator C-Mod and ASDEX Upgrade tokamaks
Authors: Silvagni D. , Terry J.L. , McCarthy W. , Hubbard A.E. , Eich T. , Faitsch M. , Gil L. , Golfinopoulos T. , Grenfell G. , Griener M. , Happel T. , Hughes J.W. , Stroth U. , Viezzer E. , the ASDEX Upgrade Team  , the EUROfusion MST1 Team
Published: December 2021

In some conditions, I-mode plasmas can feature pedestal relaxation events (PREs) that transiently enhance the energy reaching the divertor target plates. To shed light on their appearance, characteristics and energy reaching the divertor targets, a comparative study between two tokamaks — Alcator C-Mod and ASDEX Upgrade — is carried out. It is found that PREs appear only in a subset of I-mode discharges, mainly when the plasma is close to the H-mode transition. Also, a growing oscillating precursor before the PRE onset is observed in the region close to the separatrix in both devices, and a discussion on a possible triggering mechanism is outlined. The PRE relative energy loss from the confined region is found to increase with decreasing pedestal top collisionality

ν

ped

*

. Similarly, also the relative electron temperature drop at the pedestal top, which is related to the conductive energy loss, rises with decreasing

ν

ped

*

. Based on these relations, the PRE relative energy loss in future devices such as DEMO and ARC is estimated. Finally, the divertor peak energy fluence due to the PRE is measured on each device. Those values are then compared to the model introduced in Eich et al (2017 Nucl. Mater. Energy
12 84–90) for type-I edge localized modes. The model is shown to provide an upper boundary for PRE energy fluence data, while a lower boundary is found by dividing the model by three. These two boundaries are used to make projections of the PRE divertor energy fluence to DEMO and ARC.
Mesh filtration problems with a two-flow structure of phase velocities
Authors: Ivanov M , Kremer I , Laevsky Yu
Published: December 2021

This paper deals with the problem of filtration of a two-phase incompressible fluid within the Buckley-Leverett model. From a general point of view, a two-flow structure of conservation laws is investigated. In addition, since the solution in the Buckley-Leverett model is discontinuous, conservation laws are presented in the generalized integral form. A good illustration of the approach presented is the problem of gravitational segregation of oil and water in a porous medium. For this problem, a two-flow mesh structure of conservation laws is described.
Adaptive preconditioning for a stream of SLAEs
Authors: Karpov A P , Erzunov V A , Shchanikova E B , Bartenev Yu G
Published: December 2021

The paper considers the way of reducing the time consumed to solve SLAEs with iterative methods by reusing the data structures obtained in the solution of a previous SLAE, or selecting a preconditioner from the available set of preconditioners to minimize the time of solving the next SLAEs. Such adaptive preconditioning is used to solve time-dependent nonlinear problems. SLAEs generated at the Newton iteration n-1 of every computation step are solved using the SLAE structure of the first Newton iteration and the selection of a preconditioner from the given set allows reducing the time of solving SLAEs of a varying complexity at different time steps. The adaptive preconditioning idea and its application are demonstrated for a stream of SLAEs in some RFNC-VNIIEF’s codes.
Multidimensional computational models of gas combustion in heterogeneous porous medium
Authors: Laevsky Yu , Nosova T
Published: December 2021

The processes of filtration gas combustion in heterogeneous porous medium is studying. The presence of two opposite modes of front propagation made it possible to stabilize the combustion front in a composite porous medium with piecewise constant porosity. A feature of this study is the presentation of the original model not in the traditional form of a system of parabolic equations, but in the form of integral conservation laws in terms of the temperature of the porous medium, the total gas enthalpy, and the mass of gas mixture, and the fluxes corresponding to these functions.
On solutions of the Yang-Mills equations in the algebra of h-forms
Authors: Shirokov D S
Published: December 2021

We study the Yang-Mills equations in the algebra of h-forms, which is developed in the works of N. G. Marchuk and the author. The algebra of h-forms is a special geometrization of the Clifford algebra and is a generalization of the Atiyah-K¨ahler algebra. We discuss an invariant subspace of the constant Yang-Mills operator in the algebra of h-forms and present particular classes of solutions of the Yang-Mills equations.
On the seven-diagonals splitting for the cubic spline wavelets with six vanishing moments on an interval
Authors: Shumilov B M
Published: December 2021

This study uses a zeroing property of the first six moments for constructing a splitting algorithm for the cubic spline wavelets. First, we construct a system of cubic basic spline-wavelets, realizing orthogonal conditions to all polynomials up to any degree. Then, using the homogeneous Dirichlet boundary conditions, we adapt spaces to the orthogonality to all polynomials up to the fifth degree on the closed interval. The originality of the study consists of obtaining implicit finite relations connecting the coefficients of the spline decomposition at the initial scale with the spline coefficients and wavelet coefficients at the nested scale by a tape system of linear algebraic equations with a non-degenerate matrix. After excluding the even rows of the system, the resulting transformation matrix has seven diagonals, instead of five as in the previous case with four zero moments. A modification of the system is performed, which ensures a strict diagonal dominance, and, consequently, the stability of the calculations. The comparative results of numerical experiments on approximating and calculating the derivatives of a discrete function are presented.
Estimates for solutions of systems of linear equations with circulant matrices
Authors: Volkov Yu S , Novikov S I
Published: December 2021

In the present paper we consider the problem to estimate a solution of the system of equations with a circulant matrix in uniform norm. We give the estimate for circulant matrices with diagonal dominance. The estimate is sharp. Based on this result and an idea of decomposition of the matrix into a product of matrices associated with factorization of the characteristic polynomial, we propose an estimate for any circulant matrix.
Russian-English dataset and comparative analysis of algorithms for cross-language embedding-based entity alignment
Authors: Gnezdilova V A , Apanovich Z V
Published: December 2021

The problem of data fusion from data bases and knowledge graphs in different languages is becoming increasingly important. The main step of such a fusion is the identification of equivalent entities in different knowledge graphs and merging their descriptions. This problem is known as the identity resolution, or entity alignment problem. Recently, a large group of new entity alignment methods has emerged. They look for the so called “embeddings” of entities and establish the equivalence of entities by comparing their embeddings. This paper presents experiments with embedding-based entity alignment algorithms on a Russian-English dataset. The purpose of this work is to identify language-specific features of the entity alignment algorithms. Also, future directions of research are outlined.
The selective regularization of a linear regression model
Authors: Lutay V N , Khusainov N S
Published: December 2021

This paper discusses constructing a linear regression model with regularization of the system matrix of normal equations. In contrast to the conventional ridge regression, where positive parameters are added to all diagonal terms of a matrix, in the method proposed only those matrix diagonal entries that correspond to the data with a high correlation are increased. This leads to a decrease in the matrix conditioning and, therefore, to a decrease in the corresponding coefficients of the regression equation. The selection of the entries to be increased is based on the triangular decomposition of the correlation matrix of the original dataset. The effectiveness of the method is tested on a known dataset, and it is performed not only with a ridge regression, but also with the results of applying the widespread algorithms LARS and Lasso.
A lobster-inspired multi-robot control strategy for monitoring non-stationary concentration fields
Authors: Bychkov I V , Tolstikhin A A , Ulyanov S A
Published: December 2021

We propose a new lobster-inspired chemotaxis decentralized control strategy for monitoring a non-stationary concentration field using a team of nonholonomic mobile robots. The task of the team is to locate and trace the movement of the point (or points) with the highest field value (i.e. source), provided that the robots are not aware of the dynamics of the field and can only periodically sample the field at their locations. As an example of the concentration field we consider a population of biological species modeled by a self-organizing multi-agent system with agents acting as individuals of the population in accordance with some flocking rules. The proposed strategy combines the lobsters’ plume localization behavior and flocking mechanisms to efficiently solve the problem even with a small group of robots. Simulations and experimental works on physical unicycle robots are performed to validate the efectiveness of the approach for the cases of non-stationary fields.
A computational model of the cereal leaves hydraulics
Authors: Nikolaev S V , Zubairova U S
Published: December 2021

Environmental factors and plant architectonics significantly determine its water regime, namely, the water content and its movement through the tissues forced by the difference in water potentials, turgor pressure in cells, etc. In turn, the cumulative water regime affects the functioning and growth of cells, photosynthesis, and, as a result, the plant’s growth. The leaf contributes to the formation of the water regime and characterizes the contour of the plant’s adaptive system. Nevertheless, the data on the contribution of leaves to the total resistance to water transport in the plant and the structure of the hydraulic resistance of the leaf itself is still contradictory. This paper presents the formulation and justification of the monocots leaf hydraulics model based on Darcy’s law. The model was tested in computational experiments in the Comsol 4.3b package on idealized geometric models of leaf blades. Simulations showed the dependence of water potential distribution in xylem vessels and leaf mesophyll on the permeability of these tissues and on microclimatic parameters around the leaf. The adequacy of the model parameters selected as a result of testing is discussed.
The problem of identification an unknown substance by the radiographic method
Authors: Nazarov V G
Published: December 2021

This paper considers the problem of partial identification of the chemical composition of an unknown medium by the multiple X-ray of this medium. A sample of an unknown substance is assumed to be homogeneous in its chemical composition, and the photon flux, collimated both in direction and in energy. A mathematical model for the identification problem is formulated. The approach proposed to solving the problem is based on the method of singular value decomposition of a matrix. At the first stage of the solution the problem is reduced to finding singular numbers and singular vectors for the series systems of algebraic equations linear with respect to products of unknown quantities. Then, based on the data obtained, a special function is built, called an indicator to the distinguishability of substances, which enables the sufficient conditions for the distinguishability of various substances. Based on the tabular data, calculations were made for a number of specific groups of chemical elements.
Regularization of inclusions of differential equations solutions based on the kinematics of a vector field in stability problems
Authors: Rogalev A N
Published: December 2021

This paper presents the new results of computing the inclusions of sets of solutions of ordinary differential equations corresponding to perturbations acting on the solutions of the system. The regularization of algorithms for the inclusion of solutions is investigated. Inclusions of solutions are used to study the stability over a finite time interval under perturbations of the system parameters. The boundaries of solutions sets using methods that construct symbolic formulas that characterize the behavior of the system are computed. In this case, the Influence of permanent disturbances on the solutions is taken into account. It is proposed to use the parameters of the vector field of the problem in order to compensate for a strong growth of the computable solution boundaries, which is often encountered in many methods. This means the regularization of the problem of estimating inclusions of solution sets.
On the protective layer boundary determining error in the thermal conductivity inverse problem
Authors: Tanana V P , Korzhova M E , Markov B A
Published: December 2021

The article studies the problem of determining the error introduced by the inaccuracy of determining the thickness of a protective heat-resistant coating for composite materials. The mathematical problem is the heat conduction equation on an inhomogeneous half-line. The temperature on the outer side of the half-line (x = 0) is considered unknown on an infinite time interval. To find it, the temperature is measured at the media section at the point x = x0. An analytical study of the direct problem is carried out in the work. It made it possible to formulate the inverse problem mathematically rigorously and to define functional spaces in which it is convenient to solve the inverse problem. The main difficulty to be solved in the article is to obtain an estimate of the approximate solution error. The projection regularization method is used to estimate the modulus of conditional correctness, with the help of which order-exact estimates are obtained.
A circular layout algorithm for attributed hierarchical graphs with ports
Authors: Kasyanov V N , Merculov A M , Zolotuhin T A
Published: December 2021

Information visualization based on graph models is a key component of support tools for many applications in science and engineering. The Visual Graph system is intended for visualization of big amounts of complex information on the basis of attributed hierarchical graph models. In this paper, a circular layout algorithm for attributed hierarchical graphs with ports and its effective implementation in the Visual Graph system are presented.
Support tools for functional programming distance learning and teaching
Authors: Kasyanov V N , Kasyanova E V , Malishev A A
Published: December 2021

The cloud parallel programming system CPPS being under development at the A.P. Ershov Institute of Informatics Systems SB RAS is based on the Cloud Sisal language which carries on the traditions of previous versions of the Sisal language while remaining a functional data-flow language focused on writing large scientific programs and expanding their capabilities by supporting cloud computing. In this paper, the online environment of the CPPS system which allows a user on any device with Internet access to develop and execute functional programs in the Cloud Sisal language is considered.
The diameter vulnerability of two-dimensional optimal circulant networks
Authors: Monakhova E A , Monakhov O G
Published: December 2021

This paper studies the effect of changing the diameter of the network in circulant networks of dimension two with unreliable elements (nodes, links). The well-known (Δ,D,D′, s)-problem is to find (Δ, D)-graphs with maximum degree Δ and diameter D such that the subgraphs obtained from the original graph by deleting any set of up to s vertices (edges) have diameter at most D′. For a family of optimal circulants of degree four we found the ranges of the orders of the graphs that preserve the diameter of the graph for one (two) vertex or edge failures. It is proved that in the investigated circulant networks in case of failure of one or two edges (vertices), the diameter can increase by no more than one, and in case of failure of three elements by no more than two (edge failures) or three (vertex failures). It is shown that two-dimensional optimal circulants, in comparison with two-dimensional tori, have a better diameter in case of element failures.
Co-authorship network structure analysis
Authors: Scherbakova N G , Bredikhin S V
Published: December 2021

The analysis of networks of collaboration between scientists reveals features of academic communities that help in understanding the specifics of collaborative scientific work and identifying the notable researchers. In these networks, the set of nodes consists of authors and there exists a link between two authors if they have coauthored one or more papers. This article presents an analysis of the co-authorship network based on bibliometric data retrieved from the distributed economic database. Here we use the simple network model without taking into account the strength of collaborative ties. The data were analyzed using statistical techniques in order to get such parameters as the number of papers per author, the number of authors per paper, the average number of coauthors per author and collaboration indices. We show that the largest component occupies near 90 % of the network and the node degree distribution follows a power-law. The study of typical distances between nodes and the degree of clustering makes it possible to classify the network as a ‘small world’ network.
Recovery of the parameters of a focal zone by the data of earthquakes
Authors: Bogdanov V V , Yu Derevtsov E , Volkov Yu S
Published: December 2021

We present an approach for solving the inverse kinematic problem of seismic with internal sources, based on the method of multidimensional data approximation on irregular grids. The times of arrival of elastic waves to the seismic stations are considered as known. The hodographs from earthquake to the stations are approximated for further determining the velocities of longitudinal and transverse waves using the eikonal equation. The ratio of these velocities determines the Poisson’s ratio, and the other elastic parameters of the medium can be found in units of the density. The results of implementation of the approach, based on the real data, are presented.
Modeling of solar magnetic field using the kinematic-gravitational ion dynamo model
Authors: Kochnev V A
Published: December 2021

In present article the kinematic-gravitational ion dynamo model accounting for influence of tidal forces on electric currents in ionized substances is applied to modeling of the magnetic field of the Sun. Estimates of currents and field values obtained using a seven-layer model indicate that tidal forces influence is not insignificant. A correlation method for assessment of the Sun’s polarity was created and applied for a detailed analysis of the polarity of magnetic field of the Sun in the 21 and 22 cycles.
Estimation of the probability of two consecutive passages through resonance during the descent of an asymmetric rigid body in a rarefied atmosphere
Authors: Lyubimov V V
Published: December 2021

A two-frequency nonlinear system of ordinary differential equations is considered. This system describes the perturbed motion of a rigid body with considerable asymmetry in a rarefied atmosphere. It is known that when the frequencies of this system of equations coincide, the phenomena of capture or passage through the principal resonance, which have a random nature, are possible. In this case, the probability of a passage through the resonance is calculated from the initial conditions on the separatrix. The objective of this study is to obtain an expression for estimating the probability of two consecutive passages through the resonance regions during the descent in the rarefied atmosphere of Mars of a rigid body with significant geometric and aerodynamic asymmetry.
Monte Carlo simulation of halos in the crystal clouds
Authors: Mu Q , Kablukova E G , Kargin B A , Prigarin S M
Published: December 2021

In this paper, we try to answer the question: how the multiple scattering, the sun elevation, shape and orientation of ice crystals in the cirrus clouds affect a halo pattern. To study the radiation transfer in optically anisotropic clouds, we have developed the software based on Monte Carlo method and ray tracing. In addition to halos, this software enables one to simulate “anti-halos”, which above the cloud layer can be seen by observers. We present the visualization of halos and anti-halos generated by the cirrus clouds for different shapes and orientations of ice crystals.
Measurement of the angular distribution of wavelength-shifted light emitted by TPB
Authors: Schrott J. , Sakai M. , Naugle S. , Orebi Gann G.D. , Kravitz S. , McKinsey D. , Smith R.J.
Published: December 2021

We present measurements of the angular distribution of
re-emitted light from tetraphenyl butadiene thin films when exposed
to 128 nm light, which is the peak of the liquid Argon (LAr)
scintillation spectrum, in vacuum. Films ranging from 250 nm to
5.5 μm in thickness are measured. All films were fabricated
by evaporation deposition on ultraviolet transmitting (UVT) acrylic
substrates. Preliminary comparisons of the angular distribution to
that produced by a detailed Monte Carlo model are also
presented. The current shortcomings of the model are discussed and
future plans briefly outlined.
A storyline view of the projected role of remote drivers on summer air stagnation in Europe and the United States
Authors: Garrido-Perez Jose M , Ordóñez Carlos , Barriopedro David , García-Herrera Ricardo , Schnell Jordan L , Horton Daniel E
Published: December 2021

Storylines of atmospheric circulation change, or physically self-consistent narratives of plausible future events, have recently been proposed as a non-probabilistic means to represent uncertainties in climate change projections. Here, we apply the storyline approach to 21st century projections of summer air stagnation over Europe and the United States. We use a Climate Model Intercomparison Project Phase 6 (CMIP6) ensemble to generate stagnation storylines based on the forced response of three remote drivers of the Northern Hemisphere mid-latitude atmospheric circulation: North Atlantic warming, North Pacific warming, and tropical versus Arctic warming. Under a high radiative forcing scenario (SSP5-8.5), models consistently project increases in stagnation over Europe and the U.S., but the magnitude and spatial distribution of changes vary substantially across CMIP6 ensemble members, suggesting that future projections are not well-constrained when using the ensemble mean alone. We find that the diversity of projected stagnation changes depends on the forced response of remote drivers in individual models. This is especially true in Europe, where differences of ∼2 summer stagnant days per degree of global warming are found amongst the different storyline combinations. For example, the greatest projected increase in stagnation for most European regions leads to the smallest increase in stagnation for southwestern Europe; i.e. limited North Atlantic warming combined with near-equitable tropical and Arctic warming. In the U.S., only the atmosphere over the northern Rocky Mountain states demonstrates comparable stagnation projection uncertainty, due to opposite influences of remote drivers on the meteorological conditions that lead to stagnation.
Utilization of Water Hyacinth (Eichhornia crassipes) and Corncob (Zea mays) in Epoxy-based Biocomposite Board for Cool Box Thermal Insulation Material
Authors: Sruti N M K S , Jenaneswari P R , Rahayu M R , Syamani FA
Published: December 2021

Generally, the cool box is produced using styrofoam as the main thermal insulation material. However, the use of styrofoam potentially cause pollution to the environment at the end of its useful life because it cannot decompose naturally. The effort to overcome this problem is by producing thermal insulation materials from natural sources such as water hyacinth and corncob. The purpose of this study was to determine the characteristics of biocomposite board made from combination of water hyacinth powder and corncob ash based on physical, mechanical, and thermal conductivity analysis. Biocomposite boards were produced by introducing combination of water hyacinth powder and corncorb ash (5, 10, 15%wt) into epoxy resin. The ratio of water hyacinth powder and corncob ash were 100:0 (P0), 95:5 (P1), 90:10 (P2), 85:15 (P3). The biocomposite boards were also made from water hyacinth powder and corncob powder, which ratio of 15:85 (P4) and 0:100 (P5). The results of this research revealed that type P5 board had the lowest density value (0.927 g / cm3) and the lowest water absorption value (1.53%). The P2 type board shows the highest bending strength (8.6 N/mm2) which met the requirements of JIS A 5908 for particleboards type 8. The highest value of compressive strength was observed at P5 type board which was 2.94 ± 0.53 N / mm2. The lowest thermal conductivity values were observed at P2 type boards (0.305 W / mK). It can be concluded that, P2 type board had the best thermal insulator properties among other boards in this study. The thermal insulation effectiveness assessment of biocomposite board for cool box application was conducted using P2 and P5 type boards. The assessment results demonstrated that the styrofoam cool box and commercial cool box performance for maintaining temperature were superior compared to biocomposite cool box. Therefore, it is necessary to re-examine the biocomposite cool box, especially in terms of panel assembling and the shape of the lid, to produce biocomposite cool box with thermal insulator properties comparable to the commercial cool box.
Enhancement of maltodextrin-based adhesive properties using ammonium dihydrogen phosphate (ADP)
Authors: Dewi G K , Widyorini R , Lukmandaru G
Published: December 2021

Maltodextrin is a new saccharide-based adhesive that can be potentially developed as an alternative for particleboard due to its abundant resources. The addition of ammonium dihydrogen phosphate (ADP) was expected to be able to improve the properties of the maltodextrin, especially the water resistance of the cured adhesive. This study aimed to investigate the properties of maltodextrin/ADP adhesive in the ratios of 100/0, 90/10 and 80/20 wt%. The results showed that the increasing ratio of ADP in maltodextrin-based adhesive can increase not only the insoluble matter rate during boiling condition, but also the other adhesive properties of maltodextrin by lowering the viscosity and increasing the wettability tested in salacca frond particles. The pH adhesive decreased along with the increased ADP ratio. Oneway analysis of variance and Tukey test showed that the maltodextrin/ADP ratios significantly affected the adhesive properties. The thermogravimetric analysis (TGA) of dried mixture adhesive showed the significant changes in the onset and the highest weight reduction temperature of maltodextrin after the ADP addition. The FTIR analysis detected some new peaks that were expected to be related to furan ring and carbonyl groups after the maltodextrin/ADP 90/10 and 80/20 wt% were heated at 200°C for 10 minutes and/or 15 minutes. Maltodextrin/ADP 80/20 wt% had the best adhesive properties for particleboard application.
Physical and mechanical properties of impregnated polystyrene jabon (Anthocephalus cadamba) glulam
Authors: Hadi Y S , Herliyana E N , Sulastiningsih I M , Basri E , Pari R , Abdillah I B
Published: December 2021

Jabon (Anthocephalus cadamba) laminas were impregnated with polystyrene and reached 21.2% polymer loading. The laminas were manufactured for three-layer glued laminated timber (glulam) using isocyanate glue with glue spread 280 g/m2and cold-press process. For comparison purposes, untreated glulam as control and also solid wood were prepared. The physical-mechanical properties were evaluated according to the Japanese Agricultural Standard (JAS) 234-2003. The results showed that the color of glulam was not different from polystyrene glulam. The density of polystyrene glulam was higher than untreated glulam and solid wood, but the moisture content was lower than the other. The product kinds of solid wood, untreated glulam, and polystyrene glulam did not affect shear strength and modulus of rupture (MOR), while the modulus of elasticity (MOE) of untreated glulam and hardness of polystyrene glulam were the highest values and the other products were not different one each other. Both kinds of glulam fulfilled the Japanese standard in terms of moisture content, MOR, and delamination in hot water, but MOE and shear strength did not. Regarding its advantages, polystyrene glulam could be further developed using a higher wood density.
2000 Uglegorsk earthquake
Authors: Polets A Yu
Published: December 2021

The paper presents the results of waveform inversion of the Mw 6.8 August 4 (5), 2000 Uglegorsk earthquake (Sakhalin Island, Russia). The detailed rupture process of the 2000 Uglegorsk earthquake was simulated using the waveform inversion method. The average parameters were calculated for both nodal planes. Waveform inversion was carried out on the basis of Global Seismographic Network (GSN) data. Only P-waves from BHZ channels of all stations from the GSN were used. The simulated source parameters included a double-couple source, the scalar seismic moment, the source time function, and the slip directions. The performed studies made it possible to investigate the features of the rupture development and the amplitude of displacements along the east and west-dipping nodal planes of the August 4 (5), 2000 Uglegorsk earthquake. The obtained P-slip model for the 2000 Uglegorsk earthquake source area is in good agreement with the surface manifestations of the rupture according to the field geology data and the results of geodetic inversion.
Types of strong earthquake precursor behavior obtained from world and regional catalogs of earthquakes
Authors: Rodkin M V , Andreeva M Yu , Liperovskaya E V
Published: December 2021

Typical features of seismicity inherent to the period prior to the strong earthquake occurrence are examined using the regional and world-wide earthquake catalogs by the method of construction of the Generalized vicinity of a large earthquake (GVLE). These features are foreshock power-law cascade, the weak long-term background increase in seismic activity, and the definite clustering of the main events. Worth to note, that all these features appear to indicate the loss of a stability of a system, without any reference to the physical mechanism of development of the instability. Thus, these features are expected to occur in connection with the bifurcation points in systems of other physical nature, examples of such behavior are given. Besides, a tendency of a decrease in earthquakes depth in the close GVLE vicinity was found. This precursor feature has a specific character and evidences in favor of a fluid involvement in the mechanism of earthquake occurrence.
Geomechanical parameters of sedimentary rocks of Southern Sakhalin
Authors: Kamenev P A , Bogomolov L M , Usoltseva O M , Tsoi P A , Semenov V N
Published: December 2021

The samples of terrigenous rocks of the Sakhalin were selected for geomechanical studies: the rocks of the Nevelskaya and Kholmskaya Formations from the Petropavlovsk quarry; ones of the Kholmskaya Formation on the west coast of the south of Sakhalin, rocks of the Junonskaya Formation on the east coast. The Kholmskaya Formation N1hl is represented by siltstones and interlayers of fine-grained sandstone. The Nevelskaya Formation N1nv is represented by siltstones with inclusions of tufogenic material. The Junonskaya Formation T2-Jun is represented by variegated greyish-green jaspers. Their static and dynamic parameters (strength limits, static Young’s modulus and Poisson’s ratio, cohesion and angle of internal friction) were determined. The obtained results are characterized by a significant spread of values, which is likely explained by the significant fracturing of the initial samples and the effect of anisotropy.
Mud volcanism as a dangerous phenomenon for oil and gas facilities
Authors: Ustyugov G V , Ershov V V
Published: December 2021

The research dwells on the danger of mud volcanism for human economic activity, namely, oil and gas production. We performed quantitative assessment of mud volcanoes activities, using Azerbaijan and Kerch-Taman region as examples. Average annual number of mud volcanoes eruptions is 3–4 for Azerbaijan and 1–2 for Kerch-Taman region. We estimate the catalogues of mud volcanic eruptions for those areas to be 52 % and 39 % complete, respectively. Mud volcanoes eruptions are quite frequent. In both regions, over 50 % of all recorded eruptions occur within ten years of the latest eruption. Analysis of mud volcanic eruptions catalogues shows that the volume of breccia ejected during an eruption is practically not related to how long the mud volcano was quiescent. Analysis of potential impact of seismicity on mud volcanic activity shows that the probability of mud volcanoes responding to an earthquake is 6 % and 10 % for Azerbaijan and Kerch-Taman region, respectively.
The role of anthropogenic factors in forest transformation in Southern Sakhalin
Authors: Sabirov R N
Published: December 2021

The article analyzes the forests changes in the south part of Sakhalin Island from the original, natural state as a result of its habitation and economic development. The most essential disturbances of forest cover occurred in the first half of the last century when 9 pulp-and-paper mills were built by Japanese in southern island. All acceptable and more productive dark coniferous forests for providing these mills were cut down. Moreover, significant share of the forests was destroyed because of repeated and large-scale fires, creating agricultural lands and habitable territories, construction of roads, power lines, oil-and-gas pipelines, etc. The most considerable forests transformation was on the territory of Yuzhno-Sakhalinsk, and also in Korsakovsky, Dolinsky, Anivsky, Kholmsky and Nevelsky districts.
Secondary phloem traits in mature stems of Betula ermanii in stressful environments of volcanic activity
Authors: Talskikh A I , Kopanina A V , Vlasova I I
Published: December 2021

This research summarizes the results of study of structural peculiarities of Betula ermanii growing around Baransky Volcano close to the thermal Golubye Ozera. We have performed statistical analysis of parameters of the secondary phloem of multiyear shoots and stems and found some features tied to extreme environmental conditions. We have found that structural reaction of the secondary phloem of multiyear shoots and stems of B. ermanii to the extreme conditions of post-volcanic activity of Baransky Volcano manifests itself as changes in the geometry of the conductive elements and dilatation of the radial parenchyma in the non-conductive phloem. We believe these changes to be adaptive in nature due to the need for increased conductivity in volcanic landscapes.
Pivotal role of magnetic ordering and strain in lattice thermal conductivity of chromium-trihalide monolayers
Authors: Pandey T , Peeters F M , Milošević M V
Published: December 2021

Understanding the coupling between spin and phonons is critical for controlling the lattice thermal conductivity (κ

l
) in magnetic materials, as we demonstrate here for CrX3 (X = Br and I) monolayers. We show that these compounds exhibit large spin-phonon coupling (SPC), dominated by out-of-plane vibrations of Cr atoms, resulting in significantly different phonon dispersions in ferromagnetic (FM) and paramagnetic (PM) phases. Lattice thermal conductivity calculations provide additional evidence for strong SPC, where particularly large κ

l
is found for the FM phase. Most strikingly, PM and FM phases exhibit radically different behavior with tensile strain, where κ

l
increases with strain for the PM phase, and strongly decreases for the FM phase—as we explain through analysis of phonon lifetimes and scattering rates. Taken all together, we uncover the high significance of SPC on the phonon transport in CrX3 monolayers, a result extendable to other 2D magnetic materials, that will be useful in further design of thermal spin devices.
Anomalous transport driven by ion temperature gradient instability in an anisotropic deuterium-tritium plasma
Authors: ZHANG Debing , YU Limin , XUE Erbing , ZHANG Xianmei , REN Haijun
Published: December 2021

In this work, the anomalous transport driven by the ion temperature gradient instability is investigated in an anisotropic deuterium-tritium (D-T) plasma. The anisotropic factor α, defined as the ratio of perpendicular temperature to parallel temperature, is introduced to describe the temperature anisotropy in the equilibrium distribution function. The linear dispersion relation in local kinetic limit is derived, and then numerically evaluated to study the dependence of mode frequency on the anisotropic factor α of D and the fraction of T particle ε
T by choosing three sets of typical parameters, denoted as the cyclone base case, ITER and CFETR cases. Based on the linear results, the mixing length model approximation is adopted to analyze the quasi-linear particle and energy fluxes for D and T. It is found that choosing small α and large ε
T is beneficial for the confinement of particle and energy for D and T. This work may be helpful for the estimation of turbulent transport level in the ITER and CFETR devices.
Agriculture is the primary driver of tree cover loss across the Forestière region of the Republic of Guinea, Africa
Authors: Fitzgerald Maegan , Nackoney Janet , Potapov Peter , Turubanova Svetlana
Published: December 2021

Biodiversity hotspots are conservation priority areas that feature exceptionally high levels of species endemism and high levels of habitat loss. The Guinean Forests of West Africa hotspot, home to a quarter of all the mammal species of Africa, has experienced high levels of forest loss within its protected areas. Here, we analyzed tree cover loss and its proximate drivers within Guinée Forestière, a high biodiversity region within the Guinean Forests of West Africa hotspot, both inside and outside protected areas. Using Landsat analysis ready data and a regionally calibrated, annual forest change detection model, we mapped tree cover loss occurring across this region from 2000 to 2018. We quantified the area of tree cover loss and identified proximate drivers using a statistical sample of reference data. The total tree cover loss in Guinée Forestière between years 2000 and 2018 was 10,907 km2 (SE 889 km2), which consists of approximately 25% of the region’s total land area. Of this total loss, 364 km2 (SE 91 km2) occurred within protected areas of high biodiversity value. Tree cover loss was not consistent across high biodiversity areas and did not appear to be related to protected area classification. Smallholder agriculture (subsistence and cash crop farming) was the primary driver of tree cover loss across Guinée Forestière. This research provides multitemporal spatial data on tree cover dynamics that is required for effective implementation of sustainable management and biodiversity conservation strategies within the broader socioecological landscape of Guinée Forestière. We also highlight important limitations to consider and address when using remote sensing to automate change detection across landscapes.