bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non-uniqueness of the solution of one mathematical model of an autocatalytic reaction with diffusion and the Showalter – Sidorov condition
Authors: Gavrilova O V , Manakova N A 
Published: April 2021

Abstract
The article is devoted to the numerical study of the phase space of one mathematical model of an autocatalytic reaction with diffusion, based on a degenerate system of equations for a distributed brusselator. We will obtain conditions for the existence, uniqueness or multiplicity of solutions to the Showalter – Sidorov problem and reveal the dependence of these conditions on the parameters of the system. The approach used in the numerical research of this problem is based on the reduction of the semilinear Sobolev-type equation to a system of algebraic-differential equations with the subsequent solution of this system using the Runge – Kutta method of order 4-5. The article also provides the result of a computational experiment which illustrates the operation of a program complex based on an algorithm for the numerical solution of the problem. The results of numerical simulation in the case of existence of two solutions of the investigated model are presented.
Determination of functional parameters in boundary conditions of linear hyperbolic systems by optimal control methods
Authors: Arguchintsev A V , Kedrina M S 
Published: April 2021

Abstract
An inverse problem of a functional parameter determination is considered for a hybrid system of population dynamics. Dynamics of several interacting populations is described by a system of first-order linear hyperbolic equations. The boundary conditions for this system are determined from the initial problem for ordinary differential equations. The problem is interpreted as an optimal control problem. A non-classic optimality condition of variational maximum principle type is proved. The original problem in distributed parameter systems is reduced to the optimal control problem for ordinary differential equations.
Application of hierarchical structures based on binary matrices with the generalized arithmetic of Pascal’s triangle in route building problems
Authors: Kuzmin O V , Starkov B A 
Published: April 2021

Abstract
The paper describes a method for constructing binary matrices based on Pascal’s triangle. It provides the definitions of vertical and horizontal generatrices, consisting of binary elements, and the recurrent rule of Pascal’s triangle, with the help of which a binary matrix is formed. The possibility of parametrization of generatrices is shown by identifying a combinatorial root word, called a generatrix pattern, in terms of word combinatorics. A comparative analysis is provided with the method of generalizing Pascal’s triangle using reduction modulo a prime. Combinatorial differences are shown. Discrete mathematical objects (an integer lattice and combinatorial lattice paths) are described. The paper provides the definitions of lattice paths and describes specific types of paths - the Motzkin paths and the McMahon paths. It gives some combinatorial properties of the Motzkin paths. A method for mapping a binary matrix of the Pascal triangle type to the set of points of an integer combinatorial lattice is described. A method for constructing and predicting the qualitative characteristics of navigation routes by combining binary matrices and integer lattices is developed. Possibilities of parametrization of a binary matrix and an integer lattice, taking into account practical problems, are presented.
Representations of simple Lie algebras with vectors having a zero stationary subalgebra
Authors: Yu Kuzmina E 
Published: April 2021

Abstract
The paper solves the problem of describing the representations V of compact Lie groups G and vectors v ∈ V with single stationary subgroups. It builds the classification of the representation of simple Lie algebras with vectors having a zero stationary subalgebra. If the codimension of the submanifold M
0 of dimension m in an N-dimensional Euclidean space RN
is less than the dimension and the group G is simple, then all these cases are described in the corresponding tables in sections 3 and 4.
Optimization of isolated power systems with renewables and storage batteries based on nonlinear Volterra models for the specially protected natural area of lake Baikal
Authors: Karamov D N , Sidorov D N , Muftahov I R , Zhukov A V , Liu F 
Published: April 2021

Abstract
Lake Baikal conservation as UNESCO World Heritage property, national and international environmental laws dictate specific requirements and rules for the operation of energy facilities in the specially protected areas of Lake Baikal. Such restrictions have given particular strength to penetration of the renewables and storage systems. This article presents the universal method for optimizing the structure and installed capacity of isolated power systems using the example of a real tourist base. On the basis of the pool of mathematical models and control algorithms for power equipment the unified model of isolated power system was formed. The choice of mathematical models is made in accordance to the problem specifics and the climatic indicators. For optimal control of the processes of charging and discharging and determining the operating modes of the storage batteries the model based on nonlinear integral Volterra equations was used, which takes into account the nonlinear dependence of efficiency on the state of charge. In order to solve the problem of optimizing the installed capacity of the equipment the brute-force method was used. The results showed that the optimal use is polycrystalline solar panels with a total capacity of 60 kW and storage batteries with a capacity of 336 kWh.
Mathematical modelling and design of isolation diaphragms for pressure gauges
Authors: Karyakin M I , Ustinov Yu A 
Published: April 2021

Abstract
The paper discusses some questions of equilibrium, stability and shape optimization of circular membranes with arbitrary profile along the meridian. Such membranes can be used as a flexible barrier to isolate the media on one side of a diaphragm from media on the other side, whilst allowing the transmission of pressure with minimal loss. The main goal of the analysis is to propose techniques for designing such shape of corrugated membranes that satisfy the requirements of so call “slow growing linear or almost linear” behavior of the pressure-volume diagram. The applied Kirchhoff-Love theory for non-shallow shells was used as a base for deriving nonlinear as well as linearized boundary value problems of equilibrium. A genetic algorithm was used to evaluate and optimize the characteristics of corrugated membranes. The presented analysis of the membrane with the maximum linear stroke showed its efficiency and reliability. At the same time, special attention should be paid to the basic parametrization used in modelling, since the mathematically optimal solution is not always suitable from the point of view of membrane production technology.
Finite element simulation of fibrous composites strain with stress concentrators
Authors: Polatov A M , Khaldjigitov A A , Ikramov A M , Pulatov S I 
Published: April 2021

Abstract
In the paper the problems of numerical modeling of nonlinear physical processes of elements stress-strain state of the construction materials are considered. The effect and mutual influence of stress concentrators in the form of a circular cavity, vertically located two cavities and a horizontally located system of two cavities on the strain of construction is studied.
Choosing a solvation model for simulating reactions in KOH(KOBut)/DMSO superbasic media
Authors: Kobychev V B 
Published: April 2021

Abstract
The ability of protocols based on the B2PLYPD/6-311+G**//B3LYP/6-31+G* method with various schemes for accounting for nonspecific solvation to reproduce C-H, N-H, O-H and S-H acidity in a dimethyl sulfoxide medium is considered. For a selected set of 20 compounds, typical reagents for reactions in superbasic media, the IEFPCM scheme with UFF cavity and α = 1.35 multiplier yields better results than the popular SMD model.
Discrimination of the mechanistic hypotheses for two- and three-component cross-coupling reactions by using mathematical modeling of the differential selectivity patterns
Authors: Kurokhtina A A , Larina E V , Vidyaeva E V , Lagoda N A , Schmidt A F 
Published: April 2021

Abstract
Distinguishing between several probable mechanistic hypotheses for complex catalytic reactions is a very complicated task. The main cause of such complication is the simultaneous realization of several consecutive-parallel processes under the reactions proceeding including side reactions with the participation of a catalyst. Under these circumstances, using kinetic studies of the reactions can provide unique possibilities to discriminate alternative mechanistic proposals. To achieve the goal, we offer to use the studies of the differential selectivity of such complex reactions by analysing possible correspondence of its patterns to different mathematical models describing alternative mechanistic hypotheses. Using this approach the fine mechanistic details of the catalytic cycles of two-component cross-coupling Suzuki-Miyaura and Mizoroki-Heck reactions as well as of three-component Sonogashira-type reaction coupling have been established.
The effect of the reagents nature on nucleophilic addition of acetylenes to the C=N bond of aldimines: a quantum-chemical investigation
Authors: Zubarev A A , Orel V B 
Published: April 2021

Abstract
A quantum-chemical simulation of the mechanism of ethynylation of aldimines with substituted acetylenes was carried out. Kinetic and thermodynamic characteristics of this reaction for various reacting pairs were estimated by the B2PLYPD/6-311+G**//B3LYP/6-31+G * method. It was shown that in the reaction with N-alkylaldimines, the ethynylation barrier was significantly higher than in the reaction with N-arylaldimines. The change in the substituents at acetylene has no effect on the ethynylation barriers.
Effects of mycorrhiza biofertilizer on anthocyanin contents and yield of various red rice genotypes under aerobic irrigation systems
Authors: Wangiyana W , Aryana I G P M , Dulur N W D 
Published: April 2021

Abstract
Red color in red rice kernels is because of anthocyanins, making red rice to have high health values. Mycorrhizas are reported to affect anthocyanin contents of other crops. This research aimed to examine the effects of mycorrhiza biofertilizer on grain anthocyanin contents and yield of various promising lines of red rice under aerobic irrigation systems, by conducting field experiment in Beleke, West Lombok, Indonesia, from March to July 2018, in Split Plot design with three blocks and two treatment factors, namely red rice genotypes as main plots (G04, G10, G15, G21) and AMF bio-fertilizer as sub-plots (M0= without, M1= with biofertilizer application). Results of data analysis using ANOVA and Tukey’s HSD test indicated that anthocyanin contents and almost all yield components were significantly higher on red rice supplied with AMF biofertilizer than without AMF, while those variables were mostly non-significantly different between red rice genotypes, except for 100 grain weight. Despite no interaction effects, there was a significantly positive correlation between anthocyanin contents and harvest biomass weight on red rice fertilized with AMF biofertilizers, but not on those receiving no AMF, which indicates positive effects of AMF in increasing harvest biomass and grain anthocyanins of those red rice genotypes.
Visualization of polygon topology in R2 by dividing the outer plane of the polygon
Authors: Panglipur I R , Putra E D D , Sulisawati D N 
Published: April 2021

Abstract
In geometric topology, it is very interesting to develop especially related to the visualization of similar polygons to show the existence of each topology in a two-dimensional plane (R2). The aim to be achieved is to evaluate the conceptual application through the application of the development of the theory of polygon duplication images that are similar with the aided triangle and rectangle. The method chosen in this study is basic research for aiming at discovering new knowledge that had not been previously known. of a visual illustration of a polygon where the number of duplications can be determined and the R2 field. The instrument used is a validated assessment sheet. The validity test result is 2.68 so it is included in the valid category. The visualization of polygon topology on R2 can determine the number of polygons produced by dividing the number of corner points (n) into 2 parts, namely even and odd. The phenomenon of the research result shows that the odd and even n shows an arithmetic sequence. With this division, the formula for the total polygon topology ∑ ?? is obtained using the formula for (Un) in the arithmetic sequence.
Discrete numerical solution for modelling of Phytoplankton growth
Authors: Dinnullah R N I , Fayeldi T 
Published: April 2021

AbstractPhytoplankton growth model has been observed extensively to track the movement of elements through aquatic food webs and ecological processes. This study is purposed to find numerical solution of The modelling of phytoplankton growth and know the dynamic behavior. The method used to transform the phytoplankton growth model is Finite Difference Euler Method. We focused on the existence and stability of the fixed-points. We break into two cases. The result is that all of cases is dynamically consistent with its continous model only for relatively small-step size. We present some numerical simulation to illustrate those cases. We break into two cases. The result is that all cases is dynamically consistent with its continous model only for relatively small-step size. We present some numerical simulation to illustrate those cases.
Dynamical analysis of diphtheria epidemic model with natural immunity rate on exposed individuals
Authors: Izzati N , Andriani A 
Published: April 2021

Abstract
Diphtheria disease remains endemic in some countries due to the lack of immunization coverage, such as Indonesia, where health care are something need to be pursued and optimized. In the last three years, there are still some areas in Indonesia that its complete basic immunization coverage are less than 50%. Apart from being caused by low immunization coverage, other factors as nutritional adequacy, environmental hygiene and virulence levels of the disease also influence the occurrence of diphtheria outbreaks. In this study, we propose a mathematical model that considers natural immunity rate of the exposed individuals in the spread of diphtheria. This study aims to understand the dynamics of the proposed model. The behavior of the system is known by analysing the stability of its equilibrium points. Numerical simulations using Maple are also carried out to illustrate the dynamics of the system. The stability analysis and numerical simulations show that the disease-free equilibrium point is stable if ?0 < 1, whereas the endemic equilibrium point is only feasible and stable if ?0 > 1. The results shown that complete basic immunization coverage and natural immunity rate of the population affect the basic reproduction number.
Long exact sequence of U-extension modules
Authors: Mahatma Y , Hadi I , Sumargo B 
Published: April 2021

Abstract
Let R be commutative algebra with unit element. Given any R -modules M and N, and any nonzero submodule U of M, Mahatma and Muchtadi-Alamsyah defined the k -th U -extension module of N by M for every positive integer k. Further, Mahatma showed that given any short exact sequence of R -modules and R -module homomorphisms, there exists an exact sequence of U -extension modules of N by M. It is just that the sequence consists of only limited number of nonzero modules. In this paper we investigate the conditions needed by the sequence so that it can be extended into a longer one.
Root square mean labelling of some graphs obtained from path
Authors: Ramdani R , Fanisa A Y , Gumilar S , Sarbini S 
Published: April 2021

Abstract
Let G be a graph with q edges. A labelling f of G is said to be root square mean labelling if f: V(G)UE(G)→{1,2,…,q+1} such that when each edge e = uv labelled with f(e)=[f(u)2+f(v)2/2] or f(e)=[f(u)2+f(v)2/2] then the resulting edge labels are distinct. A graph G is called a root square mean graph if G can be labelled by a root square mean labelling. In this paper we determine a root mean square labelling of two graphs obtained from path, which are corona product of ladder and complete graph with order 1, and a graph obtained from triangular snake by join one vertex with degree 2 in each triangle to a new vertex. The method of labelling construction is we need to do labeling to the vertices of the graph with label 1, 2, 3, …, q+1. The labels of the vertices are not necessarily different. The next step is we need to do labeling to the edges with the certain formula by using the vertex labeling. The edge labels must be different. By the labelling we construct, we proof that the two graphs are root square mean graphs.
Progress in climate change adaptation research
Authors: Sietsma Anne J , Ford James D , Callaghan Max W , Minx Jan C 
Published: April 2021

Abstract
The scientific literature on climate change adaptation has become too large to assess manually. Beyond standard scientometrics, questions about if and how the field is progressing thus remain largely unanswered. Here we provide a novel, inquisitive, computer-assisted evidence mapping methodology that combines expert interviews (n = 26) and structural topic modelling to evaluate open-ended research questions on progress in the field. We apply this to 62 191 adaptation-relevant scientific publications (1988–2020), selected through supervised machine learning from a comprehensive climate change query. Comparing the literature to key benchmarks of mature adaptation research, our findings align with trends in the adaptation literature observed by most experts: the field is maturing, growing rapidly, and diversifying, with social science and implementation topics arising next to the still-dominant natural sciences and impacts-focused research. Formally assessing the representativeness of IPCC citations, we find evidence of a delay effect for fast-growing areas of research like adaptation strategies and governance. Similarly, we show significant topic biases by geographic location: especially disaster and development-related topics are often studied in Southern countries by authors from the North, while Northern countries dominate governance topics. Moreover, there is a general paucity of research in some highly vulnerable countries. Experts lastly signal a need for meaningful stakeholder involvement. Expanding on the methods presented here would aid the comprehensive and transparent monitoring of adaptation research. For the evidence synthesis community, our methodology provides an example of how to move beyond the descriptive towards the inquisitive and formally evaluating research questions.
Adsorption behaviors of Congo red onto Fe2O3/Fe3O4 heterogeneous nanoparticles prepared via an alcohol-assisted combustion process
Authors: Deng Peng , Wang Zhou , Pan Zhongjun , Zhang Shuanglong , Rong Guoxiang 
Published: April 2021

Abstract
Magnetic Fe2O3/Fe3O4 heterogeneous nanoparticles were prepared through an alcohol-assisted combustion process. The composition, morphology and magnetic properties of the nanomaterials were characterized by XRD, TEM and VSM techniques. The magnetic Fe2O3/Fe3O4 heterogeneous nanomaterials were soft magnetic nanoparticles with a saturation magnetization of 38.6 emu g−1 and an average particle size of approximate 29 nm. The adsorption behavior of Congo red (CR) onto Fe2O3/Fe3O4 heterogeneous nanoparticles was examined by UV-visible absorption spectroscopy, and the data for the kinetics and the isotherm of CR adsorption onto Fe2O3/Fe3O4 heterogeneous nanoparticles were in good agreement with the pseudo-second-order model and Langmuir model, respectively, which suggested that the adsorption mechanism of CR onto Fe2O3/Fe3O4 heterogeneous nanoparticles was the chemical and monolayer adsorption. Moreover, the influence of pH on the adsorption process was investigated, and when pH was equal to and less than 7, there would be larger adsorbances.
Hybrid nanomaterials-based biomedical phototheranostic platforms
Authors: Ye Jing , Dong Xiawei , Jiang Hui , Chen Yun , Wu Chunhui , Wang Xuemei 
Published: April 2021

Abstract
The new hybrid nanomaterials have unique nanoparticle surface modification or core characteristics, with two or more chemical, physical, and optical properties. They have shown more personalized application prospects in disease management and treatment, and can significantly improve the diagnosis and treatment of various diseases. This article reviews the synthesis methods and structural characteristics of a series of new hybrid nanomaterials recently produced, including metallic oxide-containing hybrid nanomaterials, biopolymers-containing hybrid nanomaterials and in situ biosynthesis of hybrid nanomaterials. We focus on applying various types of hybrid nanomaterials in magnetic resonance imaging, photoacoustic, fluorescence imaging, and computed tomography imaging technology. At the same time, it summarizes the therapeutic effects of theranostics, cancer immunotherapy, photomedicine, and photothermal therapy under the guidance of imaging diagnosis. Finally, we briefly analyze the challenges in biomedical applications by hybrid materials as a nano-platform for imaging diagnosis and treatment and provides suggestions for future research in this field.
scConnect: a method for exploratory analysis of cell–cell communication based on single-cell RNA-sequencing data
Authors: Jakobsson Jon E T , Spjuth Ola , Lagerström Malin C 
Published: April 2021

Abstract

Motivation
Cell to cell communication is critical for all multicellular organisms, and single-cell sequencing facilitates the construction of full connectivity graphs between cell types in tissues. Such complex data structures demand novel analysis methods and tools for exploratory analysis.

Results
We propose a method to predict the putative ligand–receptor interactions between cell types from single-cell RNA-sequencing data. This is achieved by inferring and incorporating interactions in a multi-directional graph, thereby enabling contextual exploratory analysis. We demonstrate that our approach can detect common and specific interactions between cell types in mouse brain and human tumors, and that these interactions fit with expected outcomes. These interactions also include predictions made with molecular ligands integrating information from several types of genes necessary for ligand production and transport. Our implementation is general and can be appended to any transcriptome analysis pipeline to provide unbiased hypothesis generation regarding ligand to receptor interactions between cell populations or for network analysis in silico.

Availability and implementation
scConnect is open source and available as a Python package at https://github.com/JonETJakobsson/scConnect. scConnect is directly compatible with Scanpy scRNA-sequencing pipelines.

Supplementary information
Supplementary data are available at Bioinformatics online.
Analytical redundancy relationship generation on a progressive horizon for fault diagnosis of a labelled Petri net
Authors: Chouchane Amira 
Published: April 2021

Abstract
In this article, a diagnosis approach for partially observed labelled Petri nets is developed based on building a set of analytical redundancy relationships on a progressive horizon. A nominal model is used for fault detection based on a set of relationships linking the known data of the nominal behaviour. A fault model is used for fault isolation by establishing a set of relationships for each fault transition connecting the known data of the fault behaviour. The above-mentioned analytical redundancy relationships are established offline by eliminating unknown variables from the considered model. The proposed online procedure for fault diagnosis is polynomial with respect to the number of unobservable events.